xref: /src/common/lib/libx86emu/x86emu.c

/*	$NetBSD: x86emu.c,v 1.9 2014/08/04 21:40:11 joerg Exp $	*/

/****************************************************************************
*
*  Realmode X86 Emulator Library
*
*  Copyright (C) 1996-1999 SciTech Software, Inc.
*  Copyright (C) David Mosberger-Tang
*  Copyright (C) 1999 Egbert Eich
*  Copyright (C) 2007 Joerg Sonnenberger
*
*  ========================================================================
*
*  Permission to use, copy, modify, distribute, and sell this software and
*  its documentation for any purpose is hereby granted without fee,
*  provided that the above copyright notice appear in all copies and that
*  both that copyright notice and this permission notice appear in
*  supporting documentation, and that the name of the authors not be used
*  in advertising or publicity pertaining to distribution of the software
*  without specific, written prior permission.  The authors makes no
*  representations about the suitability of this software for any purpose.
*  It is provided "as is" without express or implied warranty.
*
*  THE AUTHORS DISCLAIMS ALL WARRANTIES WITH REGARD TO THIS SOFTWARE,
*  INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS, IN NO
*  EVENT SHALL THE AUTHORS BE LIABLE FOR ANY SPECIAL, INDIRECT OR
*  CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF
*  USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR
*  OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR
*  PERFORMANCE OF THIS SOFTWARE.
*
****************************************************************************/

#ifndef _KERNEL
#include <stdbool.h>
#endif

#include <x86emu/x86emu.h>
#include <x86emu/x86emu_regs.h>

static void 	x86emu_intr_raise (struct X86EMU *, uint8_t type);

static void	X86EMU_exec_one_byte(struct X86EMU *);
static void	X86EMU_exec_two_byte(struct X86EMU *);

static void	fetch_decode_modrm (struct X86EMU *);
static uint8_t	fetch_byte_imm (struct X86EMU *);
static uint16_t	fetch_word_imm (struct X86EMU *);
static uint32_t	fetch_long_imm (struct X86EMU *);
static uint8_t	fetch_data_byte (struct X86EMU *, uint32_t offset);
static uint8_t	fetch_byte (struct X86EMU *, uint segment, uint32_t offset);
static uint16_t	fetch_data_word (struct X86EMU *, uint32_t offset);
static uint16_t	fetch_word (struct X86EMU *, uint32_t segment, uint32_t offset);
static uint32_t	fetch_data_long (struct X86EMU *, uint32_t offset);
static uint32_t	fetch_long (struct X86EMU *, uint32_t segment, uint32_t offset);
static void	store_data_byte (struct X86EMU *, uint32_t offset, uint8_t val);
static void	store_byte (struct X86EMU *, uint32_t segment, uint32_t offset, uint8_t val);
static void	store_data_word (struct X86EMU *, uint32_t offset, uint16_t val);
static void	store_word (struct X86EMU *, uint32_t segment, uint32_t offset, uint16_t val);
static void	store_data_long (struct X86EMU *, uint32_t offset, uint32_t val);
static void	store_long (struct X86EMU *, uint32_t segment, uint32_t offset, uint32_t val);
static uint8_t*	decode_rl_byte_register(struct X86EMU *);
static uint16_t*	decode_rl_word_register(struct X86EMU *);
static uint32_t* 	decode_rl_long_register(struct X86EMU *);
static uint8_t* 	decode_rh_byte_register(struct X86EMU *);
static uint16_t* 	decode_rh_word_register(struct X86EMU *);
static uint32_t* 	decode_rh_long_register(struct X86EMU *);
static uint16_t* 	decode_rh_seg_register(struct X86EMU *);
static uint32_t	decode_rl_address(struct X86EMU *);

static uint8_t 	decode_and_fetch_byte(struct X86EMU *);
static uint16_t 	decode_and_fetch_word(struct X86EMU *);
static uint32_t 	decode_and_fetch_long(struct X86EMU *);

static uint8_t 	decode_and_fetch_byte_imm8(struct X86EMU *, uint8_t *);
static uint16_t 	decode_and_fetch_word_imm8(struct X86EMU *, uint8_t *);
static uint32_t 	decode_and_fetch_long_imm8(struct X86EMU *, uint8_t *);

static uint16_t 	decode_and_fetch_word_disp(struct X86EMU *, int16_t);
static uint32_t 	decode_and_fetch_long_disp(struct X86EMU *, int16_t);

static void	write_back_byte(struct X86EMU *, uint8_t);
static void	write_back_word(struct X86EMU *, uint16_t);
static void	write_back_long(struct X86EMU *, uint32_t);

static uint16_t	aaa_word (struct X86EMU *, uint16_t d);
static uint16_t	aas_word (struct X86EMU *, uint16_t d);
static uint16_t	aad_word (struct X86EMU *, uint16_t d);
static uint16_t	aam_word (struct X86EMU *, uint8_t d);
static uint8_t	adc_byte (struct X86EMU *, uint8_t d, uint8_t s);
static uint16_t	adc_word (struct X86EMU *, uint16_t d, uint16_t s);
static uint32_t	adc_long (struct X86EMU *, uint32_t d, uint32_t s);
static uint8_t	add_byte (struct X86EMU *, uint8_t d, uint8_t s);
static uint16_t	add_word (struct X86EMU *, uint16_t d, uint16_t s);
static uint32_t	add_long (struct X86EMU *, uint32_t d, uint32_t s);
static uint8_t	and_byte (struct X86EMU *, uint8_t d, uint8_t s);
static uint16_t	and_word (struct X86EMU *, uint16_t d, uint16_t s);
static uint32_t	and_long (struct X86EMU *, uint32_t d, uint32_t s);
static uint8_t	cmp_byte (struct X86EMU *, uint8_t d, uint8_t s);
static uint16_t	cmp_word (struct X86EMU *, uint16_t d, uint16_t s);
static uint32_t	cmp_long (struct X86EMU *, uint32_t d, uint32_t s);
static void	cmp_byte_no_return (struct X86EMU *, uint8_t d, uint8_t s);
static void	cmp_word_no_return (struct X86EMU *, uint16_t d, uint16_t s);
static void	cmp_long_no_return (struct X86EMU *, uint32_t d, uint32_t s);
static uint8_t	daa_byte (struct X86EMU *, uint8_t d);
static uint8_t	das_byte (struct X86EMU *, uint8_t d);
static uint8_t	dec_byte (struct X86EMU *, uint8_t d);
static uint16_t	dec_word (struct X86EMU *, uint16_t d);
static uint32_t	dec_long (struct X86EMU *, uint32_t d);
static uint8_t	inc_byte (struct X86EMU *, uint8_t d);
static uint16_t	inc_word (struct X86EMU *, uint16_t d);
static uint32_t	inc_long (struct X86EMU *, uint32_t d);
static uint8_t	or_byte (struct X86EMU *, uint8_t d, uint8_t s);
static uint16_t	or_word (struct X86EMU *, uint16_t d, uint16_t s);
static uint32_t	or_long (struct X86EMU *, uint32_t d, uint32_t s);
static uint8_t	neg_byte (struct X86EMU *, uint8_t s);
static uint16_t	neg_word (struct X86EMU *, uint16_t s);
static uint32_t	neg_long (struct X86EMU *, uint32_t s);
static uint8_t	rcl_byte (struct X86EMU *, uint8_t d, uint8_t s);
static uint16_t	rcl_word (struct X86EMU *, uint16_t d, uint8_t s);
static uint32_t	rcl_long (struct X86EMU *, uint32_t d, uint8_t s);
static uint8_t	rcr_byte (struct X86EMU *, uint8_t d, uint8_t s);
static uint16_t	rcr_word (struct X86EMU *, uint16_t d, uint8_t s);
static uint32_t	rcr_long (struct X86EMU *, uint32_t d, uint8_t s);
static uint8_t	rol_byte (struct X86EMU *, uint8_t d, uint8_t s);
static uint16_t	rol_word (struct X86EMU *, uint16_t d, uint8_t s);
static uint32_t	rol_long (struct X86EMU *, uint32_t d, uint8_t s);
static uint8_t	ror_byte (struct X86EMU *, uint8_t d, uint8_t s);
static uint16_t	ror_word (struct X86EMU *, uint16_t d, uint8_t s);
static uint32_t	ror_long (struct X86EMU *, uint32_t d, uint8_t s);
static uint8_t	shl_byte (struct X86EMU *, uint8_t d, uint8_t s);
static uint16_t	shl_word (struct X86EMU *, uint16_t d, uint8_t s);
static uint32_t	shl_long (struct X86EMU *, uint32_t d, uint8_t s);
static uint8_t	shr_byte (struct X86EMU *, uint8_t d, uint8_t s);
static uint16_t	shr_word (struct X86EMU *, uint16_t d, uint8_t s);
static uint32_t	shr_long (struct X86EMU *, uint32_t d, uint8_t s);
static uint8_t	sar_byte (struct X86EMU *, uint8_t d, uint8_t s);
static uint16_t	sar_word (struct X86EMU *, uint16_t d, uint8_t s);
static uint32_t	sar_long (struct X86EMU *, uint32_t d, uint8_t s);
static uint16_t	shld_word (struct X86EMU *, uint16_t d, uint16_t fill, uint8_t s);
static uint32_t	shld_long (struct X86EMU *, uint32_t d, uint32_t fill, uint8_t s);
static uint16_t	shrd_word (struct X86EMU *, uint16_t d, uint16_t fill, uint8_t s);
static uint32_t	shrd_long (struct X86EMU *, uint32_t d, uint32_t fill, uint8_t s);
static uint8_t	sbb_byte (struct X86EMU *, uint8_t d, uint8_t s);
static uint16_t	sbb_word (struct X86EMU *, uint16_t d, uint16_t s);
static uint32_t	sbb_long (struct X86EMU *, uint32_t d, uint32_t s);
static uint8_t	sub_byte (struct X86EMU *, uint8_t d, uint8_t s);
static uint16_t	sub_word (struct X86EMU *, uint16_t d, uint16_t s);
static uint32_t	sub_long (struct X86EMU *, uint32_t d, uint32_t s);
static void	test_byte (struct X86EMU *, uint8_t d, uint8_t s);
static void	test_word (struct X86EMU *, uint16_t d, uint16_t s);
static void	test_long (struct X86EMU *, uint32_t d, uint32_t s);
static uint8_t	xor_byte (struct X86EMU *, uint8_t d, uint8_t s);
static uint16_t	xor_word (struct X86EMU *, uint16_t d, uint16_t s);
static uint32_t	xor_long (struct X86EMU *, uint32_t d, uint32_t s);
static void	imul_byte (struct X86EMU *, uint8_t s);
static void	imul_word (struct X86EMU *, uint16_t s);
static void	imul_long (struct X86EMU *, uint32_t s);
static void	mul_byte (struct X86EMU *, uint8_t s);
static void	mul_word (struct X86EMU *, uint16_t s);
static void	mul_long (struct X86EMU *, uint32_t s);
static void	idiv_byte (struct X86EMU *, uint8_t s);
static void	idiv_word (struct X86EMU *, uint16_t s);
static void	idiv_long (struct X86EMU *, uint32_t s);
static void	div_byte (struct X86EMU *, uint8_t s);
static void	div_word (struct X86EMU *, uint16_t s);
static void	div_long (struct X86EMU *, uint32_t s);
static void	ins (struct X86EMU *, int size);
static void	outs (struct X86EMU *, int size);
static void	push_word (struct X86EMU *, uint16_t w);
static void	push_long (struct X86EMU *, uint32_t w);
static uint16_t	pop_word (struct X86EMU *);
static uint32_t	pop_long (struct X86EMU *);

/****************************************************************************
REMARKS:
Handles any pending asychronous interrupts.
****************************************************************************/
static void
x86emu_intr_dispatch(struct X86EMU *emu, uint8_t intno)
{
	if (emu->_X86EMU_intrTab[intno]) {
		(*emu->_X86EMU_intrTab[intno]) (emu, intno);
	} else {
		push_word(emu, (uint16_t) emu->x86.R_FLG);
		CLEAR_FLAG(F_IF);
		CLEAR_FLAG(F_TF);
		push_word(emu, emu->x86.R_CS);
		emu->x86.R_CS = fetch_word(emu, 0, intno * 4 + 2);
		push_word(emu, emu->x86.R_IP);
		emu->x86.R_IP = fetch_word(emu, 0, intno * 4);
	}
}

static void
x86emu_intr_handle(struct X86EMU *emu)
{
	uint8_t intno;

	if (emu->x86.intr & INTR_SYNCH) {
		intno = emu->x86.intno;
		emu->x86.intr = 0;
		x86emu_intr_dispatch(emu, intno);
	}
}
/****************************************************************************
PARAMETERS:
intrnum - Interrupt number to raise

REMARKS:
Raise the specified interrupt to be handled before the execution of the
next instruction.
****************************************************************************/
void
x86emu_intr_raise(struct X86EMU *emu, uint8_t intrnum)
{
	emu->x86.intno = intrnum;
	emu->x86.intr |= INTR_SYNCH;
}
/****************************************************************************
REMARKS:
Main execution loop for the emulator. We return from here when the system
halts, which is normally caused by a stack fault when we return from the
original real mode call.
****************************************************************************/
void
X86EMU_exec(struct X86EMU *emu)
{
	emu->x86.intr = 0;

#ifdef _KERNEL
	if (setjmp(&emu->exec_state))
		return;
#else
	if (setjmp(emu->exec_state))
		return;
#endif

	for (;;) {
		if (emu->x86.intr) {
			if (((emu->x86.intr & INTR_SYNCH) && (emu->x86.intno == 0 || emu->x86.intno == 2)) ||
			    !ACCESS_FLAG(F_IF)) {
				x86emu_intr_handle(emu);
			}
		}
		if (emu->x86.R_CS == 0 && emu->x86.R_IP == 0)
			return;
		X86EMU_exec_one_byte(emu);
		++emu->cur_cycles;
	}
}

void
X86EMU_exec_call(struct X86EMU *emu, uint16_t seg, uint16_t off)
{
	push_word(emu, 0);
	push_word(emu, 0);
	emu->x86.R_CS = seg;
	emu->x86.R_IP = off;

	X86EMU_exec(emu);
}

void
X86EMU_exec_intr(struct X86EMU *emu, uint8_t intr)
{
	push_word(emu, emu->x86.R_FLG);
	CLEAR_FLAG(F_IF);
	CLEAR_FLAG(F_TF);
	push_word(emu, 0);
	push_word(emu, 0);
	emu->x86.R_CS = (*emu->emu_rdw)(emu, intr * 4 + 2);
	emu->x86.R_IP = (*emu->emu_rdw)(emu, intr * 4);
	emu->x86.intr = 0;

	X86EMU_exec(emu);
}
/****************************************************************************
REMARKS:
Halts the system by setting the halted system flag.
****************************************************************************/
void
X86EMU_halt_sys(struct X86EMU *emu)
{
#ifdef _KERNEL
	longjmp(&emu->exec_state);
#else
	longjmp(emu->exec_state, 1);
#endif
}
/****************************************************************************
PARAMETERS:
mod		- Mod value from decoded byte
regh	- Reg h value from decoded byte
regl	- Reg l value from decoded byte

REMARKS:
Raise the specified interrupt to be handled before the execution of the
next instruction.

NOTE: Do not inline this function, as (*emu->emu_rdb) is already inline!
****************************************************************************/
static void
fetch_decode_modrm(struct X86EMU *emu)
{
	int fetched;

	fetched = fetch_byte_imm(emu);
	emu->cur_mod = (fetched >> 6) & 0x03;
	emu->cur_rh = (fetched >> 3) & 0x07;
	emu->cur_rl = (fetched >> 0) & 0x07;
}
/****************************************************************************
RETURNS:
Immediate byte value read from instruction queue

REMARKS:
This function returns the immediate byte from the instruction queue, and
moves the instruction pointer to the next value.

NOTE: Do not inline this function, as (*emu->emu_rdb) is already inline!
****************************************************************************/
static uint8_t
fetch_byte_imm(struct X86EMU *emu)
{
	uint8_t fetched;

	fetched = fetch_byte(emu, emu->x86.R_CS, emu->x86.R_IP);
	emu->x86.R_IP++;
	return fetched;
}
/****************************************************************************
RETURNS:
Immediate word value read from instruction queue

REMARKS:
This function returns the immediate byte from the instruction queue, and
moves the instruction pointer to the next value.

NOTE: Do not inline this function, as (*emu->emu_rdw) is already inline!
****************************************************************************/
static uint16_t
fetch_word_imm(struct X86EMU *emu)
{
	uint16_t fetched;

	fetched = fetch_word(emu, emu->x86.R_CS, emu->x86.R_IP);
	emu->x86.R_IP += 2;
	return fetched;
}
/****************************************************************************
RETURNS:
Immediate lone value read from instruction queue

REMARKS:
This function returns the immediate byte from the instruction queue, and
moves the instruction pointer to the next value.

NOTE: Do not inline this function, as (*emu->emu_rdw) is already inline!
****************************************************************************/
static uint32_t
fetch_long_imm(struct X86EMU *emu)
{
	uint32_t fetched;

	fetched = fetch_long(emu, emu->x86.R_CS, emu->x86.R_IP);
	emu->x86.R_IP += 4;
	return fetched;
}
/****************************************************************************
RETURNS:
Value of the default data segment

REMARKS:
Inline function that returns the default data segment for the current
instruction.

On the x86 processor, the default segment is not always DS if there is
no segment override. Address modes such as -3[BP] or 10[BP+SI] all refer to
addresses relative to SS (ie: on the stack). So, at the minimum, all
decodings of addressing modes would have to set/clear a bit describing
whether the access is relative to DS or SS.  That is the function of the
cpu-state-varible emu->x86.mode. There are several potential states:

	repe prefix seen  (handled elsewhere)
	repne prefix seen  (ditto)

	cs segment override
	ds segment override
	es segment override
	fs segment override
	gs segment override
	ss segment override

	ds/ss select (in absense of override)

Each of the above 7 items are handled with a bit in the mode field.
****************************************************************************/
static uint32_t
get_data_segment(struct X86EMU *emu)
{
	switch (emu->x86.mode & SYSMODE_SEGMASK) {
	case 0:		/* default case: use ds register */
	case SYSMODE_SEGOVR_DS:
	case SYSMODE_SEGOVR_DS | SYSMODE_SEG_DS_SS:
		return emu->x86.R_DS;
	case SYSMODE_SEG_DS_SS:/* non-overridden, use ss register */
		return emu->x86.R_SS;
	case SYSMODE_SEGOVR_CS:
	case SYSMODE_SEGOVR_CS | SYSMODE_SEG_DS_SS:
		return emu->x86.R_CS;
	case SYSMODE_SEGOVR_ES:
	case SYSMODE_SEGOVR_ES | SYSMODE_SEG_DS_SS:
		return emu->x86.R_ES;
	case SYSMODE_SEGOVR_FS:
	case SYSMODE_SEGOVR_FS | SYSMODE_SEG_DS_SS:
		return emu->x86.R_FS;
	case SYSMODE_SEGOVR_GS:
	case SYSMODE_SEGOVR_GS | SYSMODE_SEG_DS_SS:
		return emu->x86.R_GS;
	case SYSMODE_SEGOVR_SS:
	case SYSMODE_SEGOVR_SS | SYSMODE_SEG_DS_SS:
		return emu->x86.R_SS;
	}
	X86EMU_halt_sys(emu);
}
/****************************************************************************
PARAMETERS:
offset	- Offset to load data from

RETURNS:
Byte value read from the absolute memory location.

NOTE: Do not inline this function as (*emu->emu_rdX) is already inline!
****************************************************************************/
static uint8_t
fetch_data_byte(struct X86EMU *emu, uint32_t offset)
{
	return fetch_byte(emu, get_data_segment(emu), offset);
}
/****************************************************************************
PARAMETERS:
offset	- Offset to load data from

RETURNS:
Word value read from the absolute memory location.

NOTE: Do not inline this function as (*emu->emu_rdX) is already inline!
****************************************************************************/
static uint16_t
fetch_data_word(struct X86EMU *emu, uint32_t offset)
{
	return fetch_word(emu, get_data_segment(emu), offset);
}
/****************************************************************************
PARAMETERS:
offset	- Offset to load data from

RETURNS:
Long value read from the absolute memory location.

NOTE: Do not inline this function as (*emu->emu_rdX) is already inline!
****************************************************************************/
static uint32_t
fetch_data_long(struct X86EMU *emu, uint32_t offset)
{
	return fetch_long(emu, get_data_segment(emu), offset);
}
/****************************************************************************
PARAMETERS:
segment	- Segment to load data from
offset	- Offset to load data from

RETURNS:
Byte value read from the absolute memory location.

NOTE: Do not inline this function as (*emu->emu_rdX) is already inline!
****************************************************************************/
static uint8_t
fetch_byte(struct X86EMU *emu, uint32_t segment, uint32_t offset)
{
	return (*emu->emu_rdb) (emu, ((uint32_t) segment << 4) + offset);
}
/****************************************************************************
PARAMETERS:
segment	- Segment to load data from
offset	- Offset to load data from

RETURNS:
Word value read from the absolute memory location.

NOTE: Do not inline this function as (*emu->emu_rdX) is already inline!
****************************************************************************/
static uint16_t
fetch_word(struct X86EMU *emu, uint32_t segment, uint32_t offset)
{
	return (*emu->emu_rdw) (emu, ((uint32_t) segment << 4) + offset);
}
/****************************************************************************
PARAMETERS:
segment	- Segment to load data from
offset	- Offset to load data from

RETURNS:
Long value read from the absolute memory location.

NOTE: Do not inline this function as (*emu->emu_rdX) is already inline!
****************************************************************************/
static uint32_t
fetch_long(struct X86EMU *emu, uint32_t segment, uint32_t offset)
{
	return (*emu->emu_rdl) (emu, ((uint32_t) segment << 4) + offset);
}
/****************************************************************************
PARAMETERS:
offset	- Offset to store data at
val		- Value to store

REMARKS:
Writes a word value to an segmented memory location. The segment used is
the current 'default' segment, which may have been overridden.

NOTE: Do not inline this function as (*emu->emu_wrX) is already inline!
****************************************************************************/
static void
store_data_byte(struct X86EMU *emu, uint32_t offset, uint8_t val)
{
	store_byte(emu, get_data_segment(emu), offset, val);
}
/****************************************************************************
PARAMETERS:
offset	- Offset to store data at
val		- Value to store

REMARKS:
Writes a word value to an segmented memory location. The segment used is
the current 'default' segment, which may have been overridden.

NOTE: Do not inline this function as (*emu->emu_wrX) is already inline!
****************************************************************************/
static void
store_data_word(struct X86EMU *emu, uint32_t offset, uint16_t val)
{
	store_word(emu, get_data_segment(emu), offset, val);
}
/****************************************************************************
PARAMETERS:
offset	- Offset to store data at
val		- Value to store

REMARKS:
Writes a long value to an segmented memory location. The segment used is
the current 'default' segment, which may have been overridden.

NOTE: Do not inline this function as (*emu->emu_wrX) is already inline!
****************************************************************************/
static void
store_data_long(struct X86EMU *emu, uint32_t offset, uint32_t val)
{
	store_long(emu, get_data_segment(emu), offset, val);
}
/****************************************************************************
PARAMETERS:
segment	- Segment to store data at
offset	- Offset to store data at
val		- Value to store

REMARKS:
Writes a byte value to an absolute memory location.

NOTE: Do not inline this function as (*emu->emu_wrX) is already inline!
****************************************************************************/
static void
store_byte(struct X86EMU *emu, uint32_t segment, uint32_t offset, uint8_t val)
{
	(*emu->emu_wrb) (emu, ((uint32_t) segment << 4) + offset, val);
}
/****************************************************************************
PARAMETERS:
segment	- Segment to store data at
offset	- Offset to store data at
val		- Value to store

REMARKS:
Writes a word value to an absolute memory location.

NOTE: Do not inline this function as (*emu->emu_wrX) is already inline!
****************************************************************************/
static void
store_word(struct X86EMU *emu, uint32_t segment, uint32_t offset, uint16_t val)
{
	(*emu->emu_wrw) (emu, ((uint32_t) segment << 4) + offset, val);
}
/****************************************************************************
PARAMETERS:
segment	- Segment to store data at
offset	- Offset to store data at
val		- Value to store

REMARKS:
Writes a long value to an absolute memory location.

NOTE: Do not inline this function as (*emu->emu_wrX) is already inline!
****************************************************************************/
static void
store_long(struct X86EMU *emu, uint32_t segment, uint32_t offset, uint32_t val)
{
	(*emu->emu_wrl) (emu, ((uint32_t) segment << 4) + offset, val);
}
/****************************************************************************
PARAMETERS:
reg	- Register to decode

RETURNS:
Pointer to the appropriate register

REMARKS:
Return a pointer to the register given by the R/RM field of the
modrm byte, for byte operands. Also enables the decoding of instructions.
****************************************************************************/
static uint8_t *
decode_rm_byte_register(struct X86EMU *emu, int reg)
{
	switch (reg) {
	case 0:
		return &emu->x86.R_AL;
	case 1:
		return &emu->x86.R_CL;
	case 2:
		return &emu->x86.R_DL;
	case 3:
		return &emu->x86.R_BL;
	case 4:
		return &emu->x86.R_AH;
	case 5:
		return &emu->x86.R_CH;
	case 6:
		return &emu->x86.R_DH;
	case 7:
		return &emu->x86.R_BH;
	default:
		X86EMU_halt_sys(emu);
	}
}

static uint8_t *
decode_rl_byte_register(struct X86EMU *emu)
{
	return decode_rm_byte_register(emu, emu->cur_rl);
}

static uint8_t *
decode_rh_byte_register(struct X86EMU *emu)
{
	return decode_rm_byte_register(emu, emu->cur_rh);
}
/****************************************************************************
PARAMETERS:
reg	- Register to decode

RETURNS:
Pointer to the appropriate register

REMARKS:
Return a pointer to the register given by the R/RM field of the
modrm byte, for word operands.  Also enables the decoding of instructions.
****************************************************************************/
static uint16_t *
decode_rm_word_register(struct X86EMU *emu, int reg)
{
	switch (reg) {
	case 0:
		return &emu->x86.R_AX;
	case 1:
		return &emu->x86.R_CX;
	case 2:
		return &emu->x86.R_DX;
	case 3:
		return &emu->x86.R_BX;
	case 4:
		return &emu->x86.R_SP;
	case 5:
		return &emu->x86.R_BP;
	case 6:
		return &emu->x86.R_SI;
	case 7:
		return &emu->x86.R_DI;
	default:
		X86EMU_halt_sys(emu);
	}
}

static uint16_t *
decode_rl_word_register(struct X86EMU *emu)
{
	return decode_rm_word_register(emu, emu->cur_rl);
}

static uint16_t *
decode_rh_word_register(struct X86EMU *emu)
{
	return decode_rm_word_register(emu, emu->cur_rh);
}
/****************************************************************************
PARAMETERS:
reg	- Register to decode

RETURNS:
Pointer to the appropriate register

REMARKS:
Return a pointer to the register given by the R/RM field of the
modrm byte, for dword operands.  Also enables the decoding of instructions.
****************************************************************************/
static uint32_t *
decode_rm_long_register(struct X86EMU *emu, int reg)
{
	switch (reg) {
	case 0:
		return &emu->x86.R_EAX;
	case 1:
		return &emu->x86.R_ECX;
	case 2:
		return &emu->x86.R_EDX;
	case 3:
		return &emu->x86.R_EBX;
	case 4:
		return &emu->x86.R_ESP;
	case 5:
		return &emu->x86.R_EBP;
	case 6:
		return &emu->x86.R_ESI;
	case 7:
		return &emu->x86.R_EDI;
	default:
		X86EMU_halt_sys(emu);
	}
}

static uint32_t *
decode_rl_long_register(struct X86EMU *emu)
{
	return decode_rm_long_register(emu, emu->cur_rl);
}

static uint32_t *
decode_rh_long_register(struct X86EMU *emu)
{
	return decode_rm_long_register(emu, emu->cur_rh);
}

/****************************************************************************
PARAMETERS:
reg	- Register to decode

RETURNS:
Pointer to the appropriate register

REMARKS:
Return a pointer to the register given by the R/RM field of the
modrm byte, for word operands, modified from above for the weirdo
special case of segreg operands.  Also enables the decoding of instructions.
****************************************************************************/
static uint16_t *
decode_rh_seg_register(struct X86EMU *emu)
{
	switch (emu->cur_rh) {
	case 0:
		return &emu->x86.R_ES;
	case 1:
		return &emu->x86.R_CS;
	case 2:
		return &emu->x86.R_SS;
	case 3:
		return &emu->x86.R_DS;
	case 4:
		return &emu->x86.R_FS;
	case 5:
		return &emu->x86.R_GS;
	default:
		X86EMU_halt_sys(emu);
	}
}
/*
 *
 * return offset from the SIB Byte
 */
static uint32_t
decode_sib_address(struct X86EMU *emu, int sib, int mod)
{
	uint32_t base = 0, i = 0, scale = 1;

	switch (sib & 0x07) {
	case 0:
		base = emu->x86.R_EAX;
		break;
	case 1:
		base = emu->x86.R_ECX;
		break;
	case 2:
		base = emu->x86.R_EDX;
		break;
	case 3:
		base = emu->x86.R_EBX;
		break;
	case 4:
		base = emu->x86.R_ESP;
		emu->x86.mode |= SYSMODE_SEG_DS_SS;
		break;
	case 5:
		if (mod == 0) {
			base = fetch_long_imm(emu);
		} else {
			base = emu->x86.R_EBP;
			emu->x86.mode |= SYSMODE_SEG_DS_SS;
		}
		break;
	case 6:
		base = emu->x86.R_ESI;
		break;
	case 7:
		base = emu->x86.R_EDI;
		break;
	}
	switch ((sib >> 3) & 0x07) {
	case 0:
		i = emu->x86.R_EAX;
		break;
	case 1:
		i = emu->x86.R_ECX;
		break;
	case 2:
		i = emu->x86.R_EDX;
		break;
	case 3:
		i = emu->x86.R_EBX;
		break;
	case 4:
		i = 0;
		break;
	case 5:
		i = emu->x86.R_EBP;
		break;
	case 6:
		i = emu->x86.R_ESI;
		break;
	case 7:
		i = emu->x86.R_EDI;
		break;
	}
	scale = 1 << ((sib >> 6) & 0x03);
	return base + (i * scale);
}
/****************************************************************************
PARAMETERS:
rm	- RM value to decode

RETURNS:
Offset in memory for the address decoding

REMARKS:
Return the offset given by mod=00, mod=01 or mod=10 addressing.
Also enables the decoding of instructions.
****************************************************************************/
static uint32_t
decode_rl_address(struct X86EMU *emu)
{
	if (emu->x86.mode & SYSMODE_PREFIX_ADDR) {
		uint32_t offset, sib;
		/* 32-bit addressing */
		switch (emu->cur_rl) {
		case 0:
			offset = emu->x86.R_EAX;
			break;
		case 1:
			offset = emu->x86.R_ECX;
			break;
		case 2:
			offset = emu->x86.R_EDX;
			break;
		case 3:
			offset = emu->x86.R_EBX;
			break;
		case 4:
			sib = fetch_byte_imm(emu);
			offset = decode_sib_address(emu, sib, 0);
			break;
		case 5:
			if (emu->cur_mod == 0) {
				offset = fetch_long_imm(emu);
			} else {
				emu->x86.mode |= SYSMODE_SEG_DS_SS;
				offset = emu->x86.R_EBP;
			}
			break;
		case 6:
			offset = emu->x86.R_ESI;
			break;
		case 7:
			offset = emu->x86.R_EDI;
			break;
		default:
			X86EMU_halt_sys(emu);
		}
		if (emu->cur_mod == 1)
			offset += (int8_t)fetch_byte_imm(emu);
		else if (emu->cur_mod == 2)
			offset += fetch_long_imm(emu);
		return offset;
	} else {
		uint16_t offset;

		/* 16-bit addressing */
		switch (emu->cur_rl) {
		case 0:
			offset = emu->x86.R_BX + emu->x86.R_SI;
			break;
		case 1:
			offset = emu->x86.R_BX + emu->x86.R_DI;
			break;
		case 2:
			emu->x86.mode |= SYSMODE_SEG_DS_SS;
			offset = emu->x86.R_BP + emu->x86.R_SI;
			break;
		case 3:
			emu->x86.mode |= SYSMODE_SEG_DS_SS;
			offset = emu->x86.R_BP + emu->x86.R_DI;
			break;
		case 4:
			offset = emu->x86.R_SI;
			break;
		case 5:
			offset = emu->x86.R_DI;
			break;
		case 6:
			if (emu->cur_mod == 0) {
				offset = fetch_word_imm(emu);
			} else {
				emu->x86.mode |= SYSMODE_SEG_DS_SS;
				offset = emu->x86.R_BP;
			}
			break;
		case 7:
			offset = emu->x86.R_BX;
			break;
		default:
			X86EMU_halt_sys(emu);
		}
		if (emu->cur_mod == 1)
			offset += (int8_t)fetch_byte_imm(emu);
		else if (emu->cur_mod == 2)
			offset += fetch_word_imm(emu);
		return offset;
	}
}

static uint8_t
decode_and_fetch_byte(struct X86EMU *emu)
{
	if (emu->cur_mod != 3) {
		emu->cur_offset = decode_rl_address(emu);
		return fetch_data_byte(emu, emu->cur_offset);
	} else {
		return *decode_rl_byte_register(emu);
	}
}

static uint16_t
decode_and_fetch_word_disp(struct X86EMU *emu, int16_t disp)
{
	if (emu->cur_mod != 3) {
		/* TODO: A20 gate emulation */
		emu->cur_offset = decode_rl_address(emu) + disp;
		if ((emu->x86.mode & SYSMODE_PREFIX_ADDR) == 0)
			emu->cur_offset &= 0xffff;
		return fetch_data_word(emu, emu->cur_offset);
	} else {
		return *decode_rl_word_register(emu);
	}
}

static uint32_t
decode_and_fetch_long_disp(struct X86EMU *emu, int16_t disp)
{
	if (emu->cur_mod != 3) {
		/* TODO: A20 gate emulation */
		emu->cur_offset = decode_rl_address(emu) + disp;
		if ((emu->x86.mode & SYSMODE_PREFIX_ADDR) == 0)
			emu->cur_offset &= 0xffff;
		return fetch_data_long(emu, emu->cur_offset);
	} else {
		return *decode_rl_long_register(emu);
	}
}

uint16_t
decode_and_fetch_word(struct X86EMU *emu)
{
	return decode_and_fetch_word_disp(emu, 0);
}

uint32_t
decode_and_fetch_long(struct X86EMU *emu)
{
	return decode_and_fetch_long_disp(emu, 0);
}

uint8_t
decode_and_fetch_byte_imm8(struct X86EMU *emu, uint8_t *imm)
{
	if (emu->cur_mod != 3) {
		emu->cur_offset = decode_rl_address(emu);
		*imm = fetch_byte_imm(emu);
		return fetch_data_byte(emu, emu->cur_offset);
	} else {
		*imm = fetch_byte_imm(emu);
		return *decode_rl_byte_register(emu);
	}
}

static uint16_t
decode_and_fetch_word_imm8(struct X86EMU *emu, uint8_t *imm)
{
	if (emu->cur_mod != 3) {
		emu->cur_offset = decode_rl_address(emu);
		*imm = fetch_byte_imm(emu);
		return fetch_data_word(emu, emu->cur_offset);
	} else {
		*imm = fetch_byte_imm(emu);
		return *decode_rl_word_register(emu);
	}
}

static uint32_t
decode_and_fetch_long_imm8(struct X86EMU *emu, uint8_t *imm)
{
	if (emu->cur_mod != 3) {
		emu->cur_offset = decode_rl_address(emu);
		*imm = fetch_byte_imm(emu);
		return fetch_data_long(emu, emu->cur_offset);
	} else {
		*imm = fetch_byte_imm(emu);
		return *decode_rl_long_register(emu);
	}
}

static void
write_back_byte(struct X86EMU *emu, uint8_t val)
{
	if (emu->cur_mod != 3)
		store_data_byte(emu, emu->cur_offset, val);
	else
		*decode_rl_byte_register(emu) = val;
}

static void
write_back_word(struct X86EMU *emu, uint16_t val)
{
	if (emu->cur_mod != 3)
		store_data_word(emu, emu->cur_offset, val);
	else
		*decode_rl_word_register(emu) = val;
}

static void
write_back_long(struct X86EMU *emu, uint32_t val)
{
	if (emu->cur_mod != 3)
		store_data_long(emu, emu->cur_offset, val);
	else
		*decode_rl_long_register(emu) = val;
}

static void
common_inc_word_long(struct X86EMU *emu, union X86EMU_register *reg)
{
	if (emu->x86.mode & SYSMODE_PREFIX_DATA)
		reg->I32_reg.e_reg = inc_long(emu, reg->I32_reg.e_reg);
	else
		reg->I16_reg.x_reg = inc_word(emu, reg->I16_reg.x_reg);
}

static void
common_dec_word_long(struct X86EMU *emu, union X86EMU_register *reg)
{
	if (emu->x86.mode & SYSMODE_PREFIX_DATA)
		reg->I32_reg.e_reg = dec_long(emu, reg->I32_reg.e_reg);
	else
		reg->I16_reg.x_reg = dec_word(emu, reg->I16_reg.x_reg);
}

static void
common_binop_byte_rm_r(struct X86EMU *emu, uint8_t (*binop)(struct X86EMU *, uint8_t, uint8_t))
{
	uint32_t destoffset;
	uint8_t *destreg, srcval;
	uint8_t destval;

	fetch_decode_modrm(emu);
	srcval = *decode_rh_byte_register(emu);
	if (emu->cur_mod != 3) {
		destoffset = decode_rl_address(emu);
		destval = fetch_data_byte(emu, destoffset);
		destval = (*binop)(emu, destval, srcval);
		store_data_byte(emu, destoffset, destval);
	} else {
		destreg = decode_rl_byte_register(emu);
		*destreg = (*binop)(emu, *destreg, srcval);
	}
}

static void
common_binop_ns_byte_rm_r(struct X86EMU *emu, void (*binop)(struct X86EMU *, uint8_t, uint8_t))
{
	uint32_t destoffset;
	uint8_t destval, srcval;

	fetch_decode_modrm(emu);
	srcval = *decode_rh_byte_register(emu);
	if (emu->cur_mod != 3) {
		destoffset = decode_rl_address(emu);
		destval = fetch_data_byte(emu, destoffset);
	} else {
		destval = *decode_rl_byte_register(emu);
	}
	(*binop)(emu, destval, srcval);
}

static void
common_binop_word_rm_r(struct X86EMU *emu, uint16_t (*binop)(struct X86EMU *, uint16_t, uint16_t))
{
	uint32_t destoffset;
	uint16_t destval, *destreg, srcval;

	fetch_decode_modrm(emu);
	srcval = *decode_rh_word_register(emu);
	if (emu->cur_mod != 3) {
		destoffset = decode_rl_address(emu);
		destval = fetch_data_word(emu, destoffset);
		destval = (*binop)(emu, destval, srcval);
		store_data_word(emu, destoffset, destval);
	} else {
		destreg = decode_rl_word_register(emu);
		*destreg = (*binop)(emu, *destreg, srcval);
	}
}

static void
common_binop_byte_r_rm(struct X86EMU *emu, uint8_t (*binop)(struct X86EMU *, uint8_t, uint8_t))
{
	uint8_t *destreg, srcval;
	uint32_t srcoffset;

	fetch_decode_modrm(emu);
	destreg = decode_rh_byte_register(emu);
	if (emu->cur_mod != 3) {
		srcoffset = decode_rl_address(emu);
		srcval = fetch_data_byte(emu, srcoffset);
	} else {
		srcval = *decode_rl_byte_register(emu);
	}
	*destreg = (*binop)(emu, *destreg, srcval);
}

static void
common_binop_long_rm_r(struct X86EMU *emu, uint32_t (*binop)(struct X86EMU *, uint32_t, uint32_t))
{
	uint32_t destoffset;
	uint32_t destval, *destreg, srcval;

	fetch_decode_modrm(emu);
	srcval = *decode_rh_long_register(emu);
	if (emu->cur_mod != 3) {
		destoffset = decode_rl_address(emu);
		destval = fetch_data_long(emu, destoffset);
		destval = (*binop)(emu, destval, srcval);
		store_data_long(emu, destoffset, destval);
	} else {
		destreg = decode_rl_long_register(emu);
		*destreg = (*binop)(emu, *destreg, srcval);
	}
}

static void
common_binop_word_long_rm_r(struct X86EMU *emu,
    uint16_t (*binop16)(struct X86EMU *, uint16_t, uint16_t), uint32_t (*binop32)(struct X86EMU *, uint32_t, uint32_t))
{
	if (emu->x86.mode & SYSMODE_PREFIX_DATA)
		common_binop_long_rm_r(emu, binop32);
	else
		common_binop_word_rm_r(emu, binop16);
}

static void
common_binop_ns_word_rm_r(struct X86EMU *emu, void (*binop)(struct X86EMU *, uint16_t, uint16_t))
{
	uint32_t destoffset;
	uint16_t destval, srcval;

	fetch_decode_modrm(emu);
	srcval = *decode_rh_word_register(emu);
	if (emu->cur_mod != 3) {
		destoffset = decode_rl_address(emu);
		destval = fetch_data_word(emu, destoffset);
	} else {
		destval = *decode_rl_word_register(emu);
	}
	(*binop)(emu, destval, srcval);
}


static void
common_binop_ns_long_rm_r(struct X86EMU *emu, void (*binop)(struct X86EMU *, uint32_t, uint32_t))
{
	uint32_t destoffset;
	uint32_t destval, srcval;

	fetch_decode_modrm(emu);
	srcval = *decode_rh_long_register(emu);
	if (emu->cur_mod != 3) {
		destoffset = decode_rl_address(emu);
		destval = fetch_data_long(emu, destoffset);
	} else {
		destval = *decode_rl_long_register(emu);
	}
	(*binop)(emu, destval, srcval);
}

static void
common_binop_ns_word_long_rm_r(struct X86EMU *emu,
    void (*binop16)(struct X86EMU *, uint16_t, uint16_t), void (*binop32)(struct X86EMU *, uint32_t, uint32_t))
{
	if (emu->x86.mode & SYSMODE_PREFIX_DATA)
		common_binop_ns_long_rm_r(emu, binop32);
	else
		common_binop_ns_word_rm_r(emu, binop16);
}

static void
common_binop_long_r_rm(struct X86EMU *emu, uint32_t (*binop)(struct X86EMU *, uint32_t, uint32_t))
{
	uint32_t srcoffset;
	uint32_t *destreg, srcval;

	fetch_decode_modrm(emu);
	destreg = decode_rh_long_register(emu);
	if (emu->cur_mod != 3) {
		srcoffset = decode_rl_address(emu);
		srcval = fetch_data_long(emu, srcoffset);
	} else {
		srcval = *decode_rl_long_register(emu);
	}
	*destreg = (*binop)(emu, *destreg, srcval);
}

static void
common_binop_word_r_rm(struct X86EMU *emu, uint16_t (*binop)(struct X86EMU *, uint16_t, uint16_t))
{
	uint32_t srcoffset;
	uint16_t *destreg, srcval;

	fetch_decode_modrm(emu);
	destreg = decode_rh_word_register(emu);
	if (emu->cur_mod != 3) {
		srcoffset = decode_rl_address(emu);
		srcval = fetch_data_word(emu, srcoffset);
	} else {
		srcval = *decode_rl_word_register(emu);
	}
	*destreg = (*binop)(emu, *destreg, srcval);
}

static void
common_binop_word_long_r_rm(struct X86EMU *emu,
    uint16_t (*binop16)(struct X86EMU *, uint16_t, uint16_t), uint32_t (*binop32)(struct X86EMU *, uint32_t, uint32_t))
{
	if (emu->x86.mode & SYSMODE_PREFIX_DATA)
		common_binop_long_r_rm(emu, binop32);
	else
		common_binop_word_r_rm(emu, binop16);
}

static void
common_binop_byte_imm(struct X86EMU *emu, uint8_t (*binop)(struct X86EMU *, uint8_t, uint8_t))
{
	uint8_t srcval;

	srcval = fetch_byte_imm(emu);
	emu->x86.R_AL = (*binop)(emu, emu->x86.R_AL, srcval);
}

static void
common_binop_word_long_imm(struct X86EMU *emu,
    uint16_t (*binop16)(struct X86EMU *, uint16_t, uint16_t), uint32_t (*binop32)(struct X86EMU *, uint32_t, uint32_t))
{
	if (emu->x86.mode & SYSMODE_PREFIX_DATA) {
		uint32_t srcval;

		srcval = fetch_long_imm(emu);
		emu->x86.R_EAX = (*binop32)(emu, emu->x86.R_EAX, srcval);
	} else {
		uint16_t srcval;

		srcval = fetch_word_imm(emu);
		emu->x86.R_AX = (*binop16)(emu, emu->x86.R_AX, srcval);
	}
}

static void
common_push_word_long(struct X86EMU *emu, union X86EMU_register *reg)
{
	if (emu->x86.mode & SYSMODE_PREFIX_DATA)
		push_long(emu, reg->I32_reg.e_reg);
	else
		push_word(emu, reg->I16_reg.x_reg);
}

static void
common_pop_word_long(struct X86EMU *emu, union X86EMU_register *reg)
{
	if (emu->x86.mode & SYSMODE_PREFIX_DATA)
		reg->I32_reg.e_reg = pop_long(emu);
	else
		reg->I16_reg.x_reg = pop_word(emu);
}

static void
common_imul_long_IMM(struct X86EMU *emu, bool byte_imm)
{
	uint32_t srcoffset;
	uint32_t *destreg, srcval;
	int32_t imm;
	uint64_t res;

	fetch_decode_modrm(emu);
	destreg = decode_rh_long_register(emu);
	if (emu->cur_mod != 3) {
		srcoffset = decode_rl_address(emu);
		srcval = fetch_data_long(emu, srcoffset);
	} else {
		srcval = *decode_rl_long_register(emu);
	}

	if (byte_imm)
		imm = (int8_t)fetch_byte_imm(emu);
	else
		imm = fetch_long_imm(emu);
	res = (int32_t)srcval * imm;

	if (res > 0xffffffff) {
		SET_FLAG(F_CF);
		SET_FLAG(F_OF);
	} else {
		CLEAR_FLAG(F_CF);
		CLEAR_FLAG(F_OF);
	}
	*destreg = (uint32_t)res;
}

static void
common_imul_word_IMM(struct X86EMU *emu, bool byte_imm)
{
	uint32_t srcoffset;
	uint16_t *destreg, srcval;
	int16_t imm;
	uint32_t res;

	fetch_decode_modrm(emu);
	destreg = decode_rh_word_register(emu);
	if (emu->cur_mod != 3) {
		srcoffset = decode_rl_address(emu);
		srcval = fetch_data_word(emu, srcoffset);
	} else {
		srcval = *decode_rl_word_register(emu);
	}

	if (byte_imm)
		imm = (int8_t)fetch_byte_imm(emu);
	else
		imm = fetch_word_imm(emu);
	res = (int16_t)srcval * imm;

	if (res > 0xffff) {
		SET_FLAG(F_CF);
		SET_FLAG(F_OF);
	} else {
		CLEAR_FLAG(F_CF);
		CLEAR_FLAG(F_OF);
	}
	*destreg = (uint16_t) res;
}

static void
common_imul_imm(struct X86EMU *emu, bool byte_imm)
{
	if (emu->x86.mode & SYSMODE_PREFIX_DATA)
		common_imul_long_IMM(emu, byte_imm);
	else
		common_imul_word_IMM(emu, byte_imm);
}

static void
common_jmp_near(struct X86EMU *emu, bool cond)
{
	int8_t offset;
	uint16_t target;

	offset = (int8_t) fetch_byte_imm(emu);
	target = (uint16_t) (emu->x86.R_IP + (int16_t) offset);
	if (cond)
		emu->x86.R_IP = target;
}

static void
common_load_far_pointer(struct X86EMU *emu, uint16_t *seg)
{
	uint16_t *dstreg;
	uint32_t srcoffset;

	fetch_decode_modrm(emu);
	if (emu->cur_mod == 3)
		X86EMU_halt_sys(emu);

	dstreg = decode_rh_word_register(emu);
	srcoffset = decode_rl_address(emu);
	*dstreg = fetch_data_word(emu, srcoffset);
	*seg = fetch_data_word(emu, srcoffset + 2);
}

/*----------------------------- Implementation ----------------------------*/
/****************************************************************************
REMARKS:
Handles opcode 0x3a
****************************************************************************/
static void
x86emuOp_cmp_byte_R_RM(struct X86EMU *emu)
{
	uint8_t *destreg, srcval;

	fetch_decode_modrm(emu);
	destreg = decode_rh_byte_register(emu);
	srcval = decode_and_fetch_byte(emu);
	cmp_byte(emu, *destreg, srcval);
}
/****************************************************************************
REMARKS:
Handles opcode 0x3b
****************************************************************************/
static void
x86emuOp32_cmp_word_R_RM(struct X86EMU *emu)
{
	uint32_t srcval, *destreg;

	fetch_decode_modrm(emu);
	destreg = decode_rh_long_register(emu);
	srcval = decode_and_fetch_long(emu);
	cmp_long(emu, *destreg, srcval);
}

static void
x86emuOp16_cmp_word_R_RM(struct X86EMU *emu)
{
	uint16_t srcval, *destreg;

	fetch_decode_modrm(emu);
	destreg = decode_rh_word_register(emu);
	srcval = decode_and_fetch_word(emu);
	cmp_word(emu, *destreg, srcval);
}

static void
x86emuOp_cmp_word_R_RM(struct X86EMU *emu)
{
	if (emu->x86.mode & SYSMODE_PREFIX_DATA)
		x86emuOp32_cmp_word_R_RM(emu);
	else
		x86emuOp16_cmp_word_R_RM(emu);
}
/****************************************************************************
REMARKS:
Handles opcode 0x3c
****************************************************************************/
static void
x86emuOp_cmp_byte_AL_IMM(struct X86EMU *emu)
{
	uint8_t srcval;

	srcval = fetch_byte_imm(emu);
	cmp_byte(emu, emu->x86.R_AL, srcval);
}
/****************************************************************************
REMARKS:
Handles opcode 0x3d
****************************************************************************/
static void
x86emuOp32_cmp_word_AX_IMM(struct X86EMU *emu)
{
	uint32_t srcval;

	srcval = fetch_long_imm(emu);
	cmp_long(emu, emu->x86.R_EAX, srcval);
}

static void
x86emuOp16_cmp_word_AX_IMM(struct X86EMU *emu)
{
	uint16_t srcval;

	srcval = fetch_word_imm(emu);
	cmp_word(emu, emu->x86.R_AX, srcval);
}

static void
x86emuOp_cmp_word_AX_IMM(struct X86EMU *emu)
{
	if (emu->x86.mode & SYSMODE_PREFIX_DATA)
		x86emuOp32_cmp_word_AX_IMM(emu);
	else
		x86emuOp16_cmp_word_AX_IMM(emu);
}
/****************************************************************************
REMARKS:
Handles opcode 0x60
****************************************************************************/
static void
x86emuOp_push_all(struct X86EMU *emu)
{
	if (emu->x86.mode & SYSMODE_PREFIX_DATA) {
		uint32_t old_sp = emu->x86.R_ESP;

		push_long(emu, emu->x86.R_EAX);
		push_long(emu, emu->x86.R_ECX);
		push_long(emu, emu->x86.R_EDX);
		push_long(emu, emu->x86.R_EBX);
		push_long(emu, old_sp);
		push_long(emu, emu->x86.R_EBP);
		push_long(emu, emu->x86.R_ESI);
		push_long(emu, emu->x86.R_EDI);
	} else {
		uint16_t old_sp = emu->x86.R_SP;

		push_word(emu, emu->x86.R_AX);
		push_word(emu, emu->x86.R_CX);
		push_word(emu, emu->x86.R_DX);
		push_word(emu, emu->x86.R_BX);
		push_word(emu, old_sp);
		push_word(emu, emu->x86.R_BP);
		push_word(emu, emu->x86.R_SI);
		push_word(emu, emu->x86.R_DI);
	}
}
/****************************************************************************
REMARKS:
Handles opcode 0x61
****************************************************************************/
static void
x86emuOp_pop_all(struct X86EMU *emu)
{
	if (emu->x86.mode & SYSMODE_PREFIX_DATA) {
		emu->x86.R_EDI = pop_long(emu);
		emu->x86.R_ESI = pop_long(emu);
		emu->x86.R_EBP = pop_long(emu);
		emu->x86.R_ESP += 4;	/* skip ESP */
		emu->x86.R_EBX = pop_long(emu);
		emu->x86.R_EDX = pop_long(emu);
		emu->x86.R_ECX = pop_long(emu);
		emu->x86.R_EAX = pop_long(emu);
	} else {
		emu->x86.R_DI = pop_word(emu);
		emu->x86.R_SI = pop_word(emu);
		emu->x86.R_BP = pop_word(emu);
		emu->x86.R_SP += 2;/* skip SP */
		emu->x86.R_BX = pop_word(emu);
		emu->x86.R_DX = pop_word(emu);
		emu->x86.R_CX = pop_word(emu);
		emu->x86.R_AX = pop_word(emu);
	}
}
/*opcode 0x62   ILLEGAL OP, calls x86emuOp_illegal_op() */
/*opcode 0x63   ILLEGAL OP, calls x86emuOp_illegal_op() */

/****************************************************************************
REMARKS:
Handles opcode 0x68
****************************************************************************/
static void
x86emuOp_push_word_IMM(struct X86EMU *emu)
{
	if (emu->x86.mode & SYSMODE_PREFIX_DATA) {
		uint32_t imm;

		imm = fetch_long_imm(emu);
		push_long(emu, imm);
	} else {
		uint16_t imm;

		imm = fetch_word_imm(emu);
		push_word(emu, imm);
	}
}
/****************************************************************************
REMARKS:
Handles opcode 0x6a
****************************************************************************/
static void
x86emuOp_push_byte_IMM(struct X86EMU *emu)
{
	int16_t imm;

	imm = (int8_t) fetch_byte_imm(emu);
	if (emu->x86.mode & SYSMODE_PREFIX_DATA) {
		push_long(emu, (int32_t) imm);
	} else {
		push_word(emu, imm);
	}
}
/****************************************************************************
REMARKS:
Handles opcode 0x6c
****************************************************************************/
/****************************************************************************
REMARKS:
Handles opcode 0x6d
****************************************************************************/
static void
x86emuOp_ins_word(struct X86EMU *emu)
{
	if (emu->x86.mode & SYSMODE_PREFIX_DATA) {
		ins(emu, 4);
	} else {
		ins(emu, 2);
	}
}
/****************************************************************************
REMARKS:
Handles opcode 0x6f
****************************************************************************/
static void
x86emuOp_outs_word(struct X86EMU *emu)
{
	if (emu->x86.mode & SYSMODE_PREFIX_DATA) {
		outs(emu, 4);
	} else {
		outs(emu, 2);
	}
}
/****************************************************************************
REMARKS:
Handles opcode 0x7c
****************************************************************************/
static void
x86emuOp_jump_near_L(struct X86EMU *emu)
{
	bool sf, of;

	sf = ACCESS_FLAG(F_SF) != 0;
	of = ACCESS_FLAG(F_OF) != 0;

	common_jmp_near(emu, sf != of);
}
/****************************************************************************
REMARKS:
Handles opcode 0x7d
****************************************************************************/
static void
x86emuOp_jump_near_NL(struct X86EMU *emu)
{
	bool sf, of;

	sf = ACCESS_FLAG(F_SF) != 0;
	of = ACCESS_FLAG(F_OF) != 0;

	common_jmp_near(emu, sf == of);
}
/****************************************************************************
REMARKS:
Handles opcode 0x7e
****************************************************************************/
static void
x86emuOp_jump_near_LE(struct X86EMU *emu)
{
	bool sf, of;

	sf = ACCESS_FLAG(F_SF) != 0;
	of = ACCESS_FLAG(F_OF) != 0;

	common_jmp_near(emu, sf != of || ACCESS_FLAG(F_ZF));
}
/****************************************************************************
REMARKS:
Handles opcode 0x7f
****************************************************************************/
static void
x86emuOp_jump_near_NLE(struct X86EMU *emu)
{
	bool sf, of;

	sf = ACCESS_FLAG(F_SF) != 0;
	of = ACCESS_FLAG(F_OF) != 0;

	common_jmp_near(emu, sf == of && !ACCESS_FLAG(F_ZF));
}

static
uint8_t(*const opc80_byte_operation[]) (struct X86EMU *, uint8_t d, uint8_t s) =
{
	add_byte,		/* 00 */
	or_byte,		/* 01 */
	adc_byte,		/* 02 */
	sbb_byte,		/* 03 */
	and_byte,		/* 04 */
	sub_byte,		/* 05 */
	xor_byte,		/* 06 */
	cmp_byte,		/* 07 */
};
/****************************************************************************
REMARKS:
Handles opcode 0x80
****************************************************************************/
static void
x86emuOp_opc80_byte_RM_IMM(struct X86EMU *emu)
{
	uint8_t imm, destval;

	/*
         * Weirdo special case instruction format.  Part of the opcode
         * held below in "RH".  Doubly nested case would result, except
         * that the decoded instruction
         */
	fetch_decode_modrm(emu);
	destval = decode_and_fetch_byte(emu);
	imm = fetch_byte_imm(emu);
	destval = (*opc80_byte_operation[emu->cur_rh]) (emu, destval, imm);
	if (emu->cur_rh != 7)
		write_back_byte(emu, destval);
}

static
uint16_t(* const opc81_word_operation[]) (struct X86EMU *, uint16_t d, uint16_t s) =
{
	add_word,		/* 00 */
	or_word,		/* 01 */
	adc_word,		/* 02 */
	sbb_word,		/* 03 */
	and_word,		/* 04 */
	sub_word,		/* 05 */
	xor_word,		/* 06 */
	cmp_word,		/* 07 */
};

static
uint32_t(* const opc81_long_operation[]) (struct X86EMU *, uint32_t d, uint32_t s) =
{
	add_long,		/* 00 */
	or_long,		/* 01 */
	adc_long,		/* 02 */
	sbb_long,		/* 03 */
	and_long,		/* 04 */
	sub_long,		/* 05 */
	xor_long,		/* 06 */
	cmp_long,		/* 07 */
};
/****************************************************************************
REMARKS:
Handles opcode 0x81
****************************************************************************/
static void
x86emuOp32_opc81_word_RM_IMM(struct X86EMU *emu)
{
	uint32_t destval, imm;

	/*
         * Weirdo special case instruction format.  Part of the opcode
         * held below in "RH".  Doubly nested case would result, except
         * that the decoded instruction
         */
	fetch_decode_modrm(emu);
	destval = decode_and_fetch_long(emu);
	imm = fetch_long_imm(emu);
	destval = (*opc81_long_operation[emu->cur_rh]) (emu, destval, imm);
	if (emu->cur_rh != 7)
		write_back_long(emu, destval);
}

static void
x86emuOp16_opc81_word_RM_IMM(struct X86EMU *emu)
{
	uint16_t destval, imm;

	/*
         * Weirdo special case instruction format.  Part of the opcode
         * held below in "RH".  Doubly nested case would result, except
         * that the decoded instruction
         */
	fetch_decode_modrm(emu);
	destval = decode_and_fetch_word(emu);
	imm = fetch_word_imm(emu);
	destval = (*opc81_word_operation[emu->cur_rh]) (emu, destval, imm);
	if (emu->cur_rh != 7)
		write_back_word(emu, destval);
}

static void
x86emuOp_opc81_word_RM_IMM(struct X86EMU *emu)
{
	if (emu->x86.mode & SYSMODE_PREFIX_DATA)
		x86emuOp32_opc81_word_RM_IMM(emu);
	else
		x86emuOp16_opc81_word_RM_IMM(emu);
}

static
uint8_t(* const opc82_byte_operation[]) (struct X86EMU *, uint8_t s, uint8_t d) =
{
	add_byte,		/* 00 */
	or_byte,		/* 01 *//* YYY UNUSED ???? */
	adc_byte,		/* 02 */
	sbb_byte,		/* 03 */
	and_byte,		/* 04 *//* YYY UNUSED ???? */
	sub_byte,		/* 05 */
	xor_byte,		/* 06 *//* YYY UNUSED ???? */
	cmp_byte,		/* 07 */
};
/****************************************************************************
REMARKS:
Handles opcode 0x82
****************************************************************************/
static void
x86emuOp_opc82_byte_RM_IMM(struct X86EMU *emu)
{
	uint8_t imm, destval;

	/*
         * Weirdo special case instruction format.  Part of the opcode
         * held below in "RH".  Doubly nested case would result, except
         * that the decoded instruction Similar to opcode 81, except that
         * the immediate byte is sign extended to a word length.
         */
	fetch_decode_modrm(emu);
	destval = decode_and_fetch_byte(emu);
	imm = fetch_byte_imm(emu);
	destval = (*opc82_byte_operation[emu->cur_rh]) (emu, destval, imm);
	if (emu->cur_rh != 7)
		write_back_byte(emu, destval);
}

static
uint16_t(* const opc83_word_operation[]) (struct X86EMU *, uint16_t s, uint16_t d) =
{
	add_word,		/* 00 */
	or_word,		/* 01 *//* YYY UNUSED ???? */
	adc_word,		/* 02 */
	sbb_word,		/* 03 */
	and_word,		/* 04 *//* YYY UNUSED ???? */
	sub_word,		/* 05 */
	xor_word,		/* 06 *//* YYY UNUSED ???? */
	cmp_word,		/* 07 */
};

static
uint32_t(* const opc83_long_operation[]) (struct X86EMU *, uint32_t s, uint32_t d) =
{
	add_long,		/* 00 */
	or_long,		/* 01 *//* YYY UNUSED ???? */
	adc_long,		/* 02 */
	sbb_long,		/* 03 */
	and_long,		/* 04 *//* YYY UNUSED ???? */
	sub_long,		/* 05 */
	xor_long,		/* 06 *//* YYY UNUSED ???? */
	cmp_long,		/* 07 */
};
/****************************************************************************
REMARKS:
Handles opcode 0x83
****************************************************************************/
static void
x86emuOp32_opc83_word_RM_IMM(struct X86EMU *emu)
{
	uint32_t destval, imm;

	fetch_decode_modrm(emu);
	destval = decode_and_fetch_long(emu);
	imm = (int8_t) fetch_byte_imm(emu);
	destval = (*opc83_long_operation[emu->cur_rh]) (emu, destval, imm);
	if (emu->cur_rh != 7)
		write_back_long(emu, destval);
}

static void
x86emuOp16_opc83_word_RM_IMM(struct X86EMU *emu)
{
	uint16_t destval, imm;

	fetch_decode_modrm(emu);
	destval = decode_and_fetch_word(emu);
	imm = (int8_t) fetch_byte_imm(emu);
	destval = (*opc83_word_operation[emu->cur_rh]) (emu, destval, imm);
	if (emu->cur_rh != 7)
		write_back_word(emu, destval);
}

static void
x86emuOp_opc83_word_RM_IMM(struct X86EMU *emu)
{
	if (emu->x86.mode & SYSMODE_PREFIX_DATA)
		x86emuOp32_opc83_word_RM_IMM(emu);
	else
		x86emuOp16_opc83_word_RM_IMM(emu);
}
/****************************************************************************
REMARKS:
Handles opcode 0x86
****************************************************************************/
static void
x86emuOp_xchg_byte_RM_R(struct X86EMU *emu)
{
	uint8_t *srcreg, destval, tmp;

	fetch_decode_modrm(emu);
	destval = decode_and_fetch_byte(emu);
	srcreg = decode_rh_byte_register(emu);
	tmp = destval;
	destval = *srcreg;
	*srcreg = tmp;
	write_back_byte(emu, destval);
}
/****************************************************************************
REMARKS:
Handles opcode 0x87
****************************************************************************/
static void
x86emuOp32_xchg_word_RM_R(struct X86EMU *emu)
{
	uint32_t *srcreg, destval, tmp;

	fetch_decode_modrm(emu);
	destval = decode_and_fetch_long(emu);
	srcreg = decode_rh_long_register(emu);
	tmp = destval;
	destval = *srcreg;
	*srcreg = tmp;
	write_back_long(emu, destval);
}

static void
x86emuOp16_xchg_word_RM_R(struct X86EMU *emu)
{
	uint16_t *srcreg, destval, tmp;

	fetch_decode_modrm(emu);
	destval = decode_and_fetch_word(emu);
	srcreg = decode_rh_word_register(emu);
	tmp = destval;
	destval = *srcreg;
	*srcreg = tmp;
	write_back_word(emu, destval);
}

static void
x86emuOp_xchg_word_RM_R(struct X86EMU *emu)
{
	if (emu->x86.mode & SYSMODE_PREFIX_DATA)
		x86emuOp32_xchg_word_RM_R(emu);
	else
		x86emuOp16_xchg_word_RM_R(emu);
}
/****************************************************************************
REMARKS:
Handles opcode 0x88
****************************************************************************/
static void
x86emuOp_mov_byte_RM_R(struct X86EMU *emu)
{
	uint8_t *destreg, *srcreg;
	uint32_t destoffset;

	fetch_decode_modrm(emu);
	srcreg = decode_rh_byte_register(emu);
	if (emu->cur_mod != 3) {
		destoffset = decode_rl_address(emu);
		store_data_byte(emu, destoffset, *srcreg);
	} else {
		destreg = decode_rl_byte_register(emu);
		*destreg = *srcreg;
	}
}
/****************************************************************************
REMARKS:
Handles opcode 0x89
****************************************************************************/
static void
x86emuOp32_mov_word_RM_R(struct X86EMU *emu)
{
	uint32_t destoffset;
	uint32_t *destreg, srcval;

	fetch_decode_modrm(emu);
	srcval = *decode_rh_long_register(emu);
	if (emu->cur_mod != 3) {
		destoffset = decode_rl_address(emu);
		store_data_long(emu, destoffset, srcval);
	} else {
		destreg = decode_rl_long_register(emu);
		*destreg = srcval;
	}
}

static void
x86emuOp16_mov_word_RM_R(struct X86EMU *emu)
{
	uint32_t destoffset;
	uint16_t *destreg, srcval;

	fetch_decode_modrm(emu);
	srcval = *decode_rh_word_register(emu);
	if (emu->cur_mod != 3) {
		destoffset = decode_rl_address(emu);
		store_data_word(emu, destoffset, srcval);
	} else {
		destreg = decode_rl_word_register(emu);
		*destreg = srcval;
	}
}

static void
x86emuOp_mov_word_RM_R(struct X86EMU *emu)
{
	if (emu->x86.mode & SYSMODE_PREFIX_DATA)
		x86emuOp32_mov_word_RM_R(emu);
	else
		x86emuOp16_mov_word_RM_R(emu);
}
/****************************************************************************
REMARKS:
Handles opcode 0x8a
****************************************************************************/
static void
x86emuOp_mov_byte_R_RM(struct X86EMU *emu)
{
	uint8_t *destreg;

	fetch_decode_modrm(emu);
	destreg = decode_rh_byte_register(emu);
	*destreg = decode_and_fetch_byte(emu);
}
/****************************************************************************
REMARKS:
Handles opcode 0x8b
****************************************************************************/
static void
x86emuOp_mov_word_R_RM(struct X86EMU *emu)
{
	if (emu->x86.mode & SYSMODE_PREFIX_DATA) {
		uint32_t *destreg;

		fetch_decode_modrm(emu);
		destreg = decode_rh_long_register(emu);
		*destreg = decode_and_fetch_long(emu);
	} else {
		uint16_t *destreg;

		fetch_decode_modrm(emu);
		destreg = decode_rh_word_register(emu);
		*destreg = decode_and_fetch_word(emu);
	}
}
/****************************************************************************
REMARKS:
Handles opcode 0x8c
****************************************************************************/
static void
x86emuOp_mov_word_RM_SR(struct X86EMU *emu)
{
	uint16_t *destreg, srcval;
	uint32_t destoffset;

	fetch_decode_modrm(emu);
	srcval = *decode_rh_seg_register(emu);
	if (emu->cur_mod != 3) {
		destoffset = decode_rl_address(emu);
		store_data_word(emu, destoffset, srcval);
	} else {
		destreg = decode_rl_word_register(emu);
		*destreg = srcval;
	}
}
/****************************************************************************
REMARKS:
Handles opcode 0x8d
****************************************************************************/
static void
x86emuOp_lea_word_R_M(struct X86EMU *emu)
{
	uint32_t destoffset;

	fetch_decode_modrm(emu);
	if (emu->cur_mod == 3)
		X86EMU_halt_sys(emu);

	destoffset = decode_rl_address(emu);
	if (emu->x86.mode & SYSMODE_PREFIX_ADDR) {
		uint32_t *srcreg;

		srcreg = decode_rh_long_register(emu);
		*srcreg = (uint32_t) destoffset;
	} else {
		uint16_t *srcreg;

		srcreg = decode_rh_word_register(emu);
		*srcreg = (uint16_t) destoffset;
	}
}
/****************************************************************************
REMARKS:
Handles opcode 0x8e
****************************************************************************/
static void
x86emuOp_mov_word_SR_RM(struct X86EMU *emu)
{
	uint16_t *destreg;

	fetch_decode_modrm(emu);
	destreg = decode_rh_seg_register(emu);
	*destreg = decode_and_fetch_word(emu);
	/*
         * Clean up, and reset all the R_xSP pointers to the correct
         * locations.  This is about 3x too much overhead (doing all the
         * segreg ptrs when only one is needed, but this instruction
         * *cannot* be that common, and this isn't too much work anyway.
         */
}
/****************************************************************************
REMARKS:
Handles opcode 0x8f
****************************************************************************/
static void
x86emuOp32_pop_RM(struct X86EMU *emu)
{
	uint32_t destoffset;
	uint32_t destval, *destreg;

	fetch_decode_modrm(emu);
	if (emu->cur_mod != 3) {
		destoffset = decode_rl_address(emu);
		destval = pop_long(emu);
		store_data_long(emu, destoffset, destval);
	} else {
		destreg = decode_rl_long_register(emu);
		*destreg = pop_long(emu);
	}
}

static void
x86emuOp16_pop_RM(struct X86EMU *emu)
{
	uint32_t destoffset;
	uint16_t destval, *destreg;

	fetch_decode_modrm(emu);
	if (emu->cur_mod != 3) {
		destoffset = decode_rl_address(emu);
		destval = pop_word(emu);
		store_data_word(emu, destoffset, destval);
	} else {
		destreg = decode_rl_word_register(emu);
		*destreg = pop_word(emu);
	}
}

static void
x86emuOp_pop_RM(struct X86EMU *emu)
{
	if (emu->x86.mode & SYSMODE_PREFIX_DATA)
		x86emuOp32_pop_RM(emu);
	else
		x86emuOp16_pop_RM(emu);
}
/****************************************************************************
REMARKS:
Handles opcode 0x91
****************************************************************************/
static void
x86emuOp_xchg_word_AX_CX(struct X86EMU *emu)
{
	uint32_t tmp;

	if (emu->x86.mode & SYSMODE_PREFIX_DATA) {
		tmp = emu->x86.R_EAX;
		emu->x86.R_EAX = emu->x86.R_ECX;
		emu->x86.R_ECX = tmp;
	} else {
		tmp = emu->x86.R_AX;
		emu->x86.R_AX = emu->x86.R_CX;
		emu->x86.R_CX = (uint16_t) tmp;
	}
}
/****************************************************************************
REMARKS:
Handles opcode 0x92
****************************************************************************/
static void
x86emuOp_xchg_word_AX_DX(struct X86EMU *emu)
{
	uint32_t tmp;

	if (emu->x86.mode & SYSMODE_PREFIX_DATA) {
		tmp = emu->x86.R_EAX;
		emu->x86.R_EAX = emu->x86.R_EDX;
		emu->x86.R_EDX = tmp;
	} else {
		tmp = emu->x86.R_AX;
		emu->x86.R_AX = emu->x86.R_DX;
		emu->x86.R_DX = (uint16_t) tmp;
	}
}
/****************************************************************************
REMARKS:
Handles opcode 0x93
****************************************************************************/
static void
x86emuOp_xchg_word_AX_BX(struct X86EMU *emu)
{
	uint32_t tmp;

	if (emu->x86.mode & SYSMODE_PREFIX_DATA) {
		tmp = emu->x86.R_EAX;
		emu->x86.R_EAX = emu->x86.R_EBX;
		emu->x86.R_EBX = tmp;
	} else {
		tmp = emu->x86.R_AX;
		emu->x86.R_AX = emu->x86.R_BX;
		emu->x86.R_BX = (uint16_t) tmp;
	}
}
/****************************************************************************
REMARKS:
Handles opcode 0x94
****************************************************************************/
static void
x86emuOp_xchg_word_AX_SP(struct X86EMU *emu)
{
	uint32_t tmp;

	if (emu->x86.mode & SYSMODE_PREFIX_DATA) {
		tmp = emu->x86.R_EAX;
		emu->x86.R_EAX = emu->x86.R_ESP;
		emu->x86.R_ESP = tmp;
	} else {
		tmp = emu->x86.R_AX;
		emu->x86.R_AX = emu->x86.R_SP;
		emu->x86.R_SP = (uint16_t) tmp;
	}
}
/****************************************************************************
REMARKS:
Handles opcode 0x95
****************************************************************************/
static void
x86emuOp_xchg_word_AX_BP(struct X86EMU *emu)
{
	uint32_t tmp;

	if (emu->x86.mode & SYSMODE_PREFIX_DATA) {
		tmp = emu->x86.R_EAX;
		emu->x86.R_EAX = emu->x86.R_EBP;
		emu->x86.R_EBP = tmp;
	} else {
		tmp = emu->x86.R_AX;
		emu->x86.R_AX = emu->x86.R_BP;
		emu->x86.R_BP = (uint16_t) tmp;
	}
}
/****************************************************************************
REMARKS:
Handles opcode 0x96
****************************************************************************/
static void
x86emuOp_xchg_word_AX_SI(struct X86EMU *emu)
{
	uint32_t tmp;

	if (emu->x86.mode & SYSMODE_PREFIX_DATA) {
		tmp = emu->x86.R_EAX;
		emu->x86.R_EAX = emu->x86.R_ESI;
		emu->x86.R_ESI = tmp;
	} else {
		tmp = emu->x86.R_AX;
		emu->x86.R_AX = emu->x86.R_SI;
		emu->x86.R_SI = (uint16_t) tmp;
	}
}
/****************************************************************************
REMARKS:
Handles opcode 0x97
****************************************************************************/
static void
x86emuOp_xchg_word_AX_DI(struct X86EMU *emu)
{
	uint32_t tmp;

	if (emu->x86.mode & SYSMODE_PREFIX_DATA) {
		tmp = emu->x86.R_EAX;
		emu->x86.R_EAX = emu->x86.R_EDI;
		emu->x86.R_EDI = tmp;
	} else {
		tmp = emu->x86.R_AX;
		emu->x86.R_AX = emu->x86.R_DI;
		emu->x86.R_DI = (uint16_t) tmp;
	}
}
/****************************************************************************
REMARKS:
Handles opcode 0x98
****************************************************************************/
static void
x86emuOp_cbw(struct X86EMU *emu)
{
	if (emu->x86.mode & SYSMODE_PREFIX_DATA) {
		if (emu->x86.R_AX & 0x8000) {
			emu->x86.R_EAX |= 0xffff0000;
		} else {
			emu->x86.R_EAX &= 0x0000ffff;
		}
	} else {
		if (emu->x86.R_AL & 0x80) {
			emu->x86.R_AH = 0xff;
		} else {
			emu->x86.R_AH = 0x0;
		}
	}
}
/****************************************************************************
REMARKS:
Handles opcode 0x99
****************************************************************************/
static void
x86emuOp_cwd(struct X86EMU *emu)
{
	if (emu->x86.mode & SYSMODE_PREFIX_DATA) {
		if (emu->x86.R_EAX & 0x80000000) {
			emu->x86.R_EDX = 0xffffffff;
		} else {
			emu->x86.R_EDX = 0x0;
		}
	} else {
		if (emu->x86.R_AX & 0x8000) {
			emu->x86.R_DX = 0xffff;
		} else {
			emu->x86.R_DX = 0x0;
		}
	}
}
/****************************************************************************
REMARKS:
Handles opcode 0x9a
****************************************************************************/
static void
x86emuOp_call_far_IMM(struct X86EMU *emu)
{
	uint16_t farseg, faroff;

	faroff = fetch_word_imm(emu);
	farseg = fetch_word_imm(emu);
	/* XXX
	 *
	 * Hooked interrupt vectors calling into our "BIOS" will cause problems
	 * unless all intersegment stuff is checked for BIOS access.  Check
	 * needed here.  For moment, let it alone. */
	push_word(emu, emu->x86.R_CS);
	emu->x86.R_CS = farseg;
	push_word(emu, emu->x86.R_IP);
	emu->x86.R_IP = faroff;
}
/****************************************************************************
REMARKS:
Handles opcode 0x9c
****************************************************************************/
static void
x86emuOp_pushf_word(struct X86EMU *emu)
{
	uint32_t flags;

	/* clear out *all* bits not representing flags, and turn on real bits */
	flags = (emu->x86.R_EFLG & F_MSK) | F_ALWAYS_ON;
	if (emu->x86.mode & SYSMODE_PREFIX_DATA) {
		push_long(emu, flags);
	} else {
		push_word(emu, (uint16_t) flags);
	}
}
/****************************************************************************
REMARKS:
Handles opcode 0x9d
****************************************************************************/
static void
x86emuOp_popf_word(struct X86EMU *emu)
{
	if (emu->x86.mode & SYSMODE_PREFIX_DATA) {
		emu->x86.R_EFLG = pop_long(emu);
	} else {
		emu->x86.R_FLG = pop_word(emu);
	}
}
/****************************************************************************
REMARKS:
Handles opcode 0x9e
****************************************************************************/
static void
x86emuOp_sahf(struct X86EMU *emu)
{
	/* clear the lower bits of the flag register */
	emu->x86.R_FLG &= 0xffffff00;
	/* or in the AH register into the flags register */
	emu->x86.R_FLG |= emu->x86.R_AH;
}
/****************************************************************************
REMARKS:
Handles opcode 0x9f
****************************************************************************/
static void
x86emuOp_lahf(struct X86EMU *emu)
{
	emu->x86.R_AH = (uint8_t) (emu->x86.R_FLG & 0xff);
	/* undocumented TC++ behavior??? Nope.  It's documented, but you have
	 * too look real hard to notice it. */
	emu->x86.R_AH |= 0x2;
}
/****************************************************************************
REMARKS:
Handles opcode 0xa0
****************************************************************************/
static void
x86emuOp_mov_AL_M_IMM(struct X86EMU *emu)
{
	uint16_t offset;

	offset = fetch_word_imm(emu);
	emu->x86.R_AL = fetch_data_byte(emu, offset);
}
/****************************************************************************
REMARKS:
Handles opcode 0xa1
****************************************************************************/
static void
x86emuOp_mov_AX_M_IMM(struct X86EMU *emu)
{
	uint16_t offset;

	offset = fetch_word_imm(emu);
	if (emu->x86.mode & SYSMODE_PREFIX_DATA) {
		emu->x86.R_EAX = fetch_data_long(emu, offset);
	} else {
		emu->x86.R_AX = fetch_data_word(emu, offset);
	}
}
/****************************************************************************
REMARKS:
Handles opcode 0xa2
****************************************************************************/
static void
x86emuOp_mov_M_AL_IMM(struct X86EMU *emu)
{
	uint16_t offset;

	offset = fetch_word_imm(emu);
	store_data_byte(emu, offset, emu->x86.R_AL);
}
/****************************************************************************
REMARKS:
Handles opcode 0xa3
****************************************************************************/
static void
x86emuOp_mov_M_AX_IMM(struct X86EMU *emu)
{
	uint16_t offset;

	offset = fetch_word_imm(emu);
	if (emu->x86.mode & SYSMODE_PREFIX_DATA) {
		store_data_long(emu, offset, emu->x86.R_EAX);
	} else {
		store_data_word(emu, offset, emu->x86.R_AX);
	}
}
/****************************************************************************
REMARKS:
Handles opcode 0xa4
****************************************************************************/
static void
x86emuOp_movs_byte(struct X86EMU *emu)
{
	uint8_t val;
	uint32_t count;
	int inc;

	if (ACCESS_FLAG(F_DF))	/* down */
		inc = -1;
	else
		inc = 1;
	count = 1;
	if (emu->x86.mode & (SYSMODE_PREFIX_REPE | SYSMODE_PREFIX_REPNE)) {
		/* dont care whether REPE or REPNE */
		/* move them until CX is ZERO. */
		count = emu->x86.R_CX;
		emu->x86.R_CX = 0;
		emu->x86.mode &= ~(SYSMODE_PREFIX_REPE | SYSMODE_PREFIX_REPNE);
	}
	while (count--) {
		val = fetch_data_byte(emu, emu->x86.R_SI);
		store_byte(emu, emu->x86.R_ES, emu->x86.R_DI, val);
		emu->x86.R_SI += inc;
		emu->x86.R_DI += inc;
	}
}
/****************************************************************************
REMARKS:
Handles opcode 0xa5
****************************************************************************/
static void
x86emuOp_movs_word(struct X86EMU *emu)
{
	uint32_t val;
	int inc;
	uint32_t count;

	if (emu->x86.mode & SYSMODE_PREFIX_DATA)
		inc = 4;
	else
		inc = 2;

	if (ACCESS_FLAG(F_DF))	/* down */
		inc = -inc;

	count = 1;
	if (emu->x86.mode & (SYSMODE_PREFIX_REPE | SYSMODE_PREFIX_REPNE)) {
		/* dont care whether REPE or REPNE */
		/* move them until CX is ZERO. */
		count = emu->x86.R_CX;
		emu->x86.R_CX = 0;
		emu->x86.mode &= ~(SYSMODE_PREFIX_REPE | SYSMODE_PREFIX_REPNE);
	}
	while (count--) {
		if (emu->x86.mode & SYSMODE_PREFIX_DATA) {
			val = fetch_data_long(emu, emu->x86.R_SI);
			store_long(emu, emu->x86.R_ES, emu->x86.R_DI, val);
		} else {
			val = fetch_data_word(emu, emu->x86.R_SI);
			store_word(emu, emu->x86.R_ES, emu->x86.R_DI, (uint16_t) val);
		}
		emu->x86.R_SI += inc;
		emu->x86.R_DI += inc;
	}
}
/****************************************************************************
REMARKS:
Handles opcode 0xa6
****************************************************************************/
static void
x86emuOp_cmps_byte(struct X86EMU *emu)
{
	int8_t val1, val2;
	int inc;

	if (ACCESS_FLAG(F_DF))	/* down */
		inc = -1;
	else
		inc = 1;

	if (emu->x86.mode & SYSMODE_PREFIX_REPE) {
		/* REPE  */
		/* move them until CX is ZERO. */
		while (emu->x86.R_CX != 0) {
			val1 = fetch_data_byte(emu, emu->x86.R_SI);
			val2 = fetch_byte(emu, emu->x86.R_ES, emu->x86.R_DI);
			cmp_byte(emu, val1, val2);
			emu->x86.R_CX -= 1;
			emu->x86.R_SI += inc;
			emu->x86.R_DI += inc;
			if (ACCESS_FLAG(F_ZF) == 0)
				break;
		}
		emu->x86.mode &= ~SYSMODE_PREFIX_REPE;
	} else if (emu->x86.mode & SYSMODE_PREFIX_REPNE) {
		/* REPNE  */
		/* move them until CX is ZERO. */
		while (emu->x86.R_CX != 0) {
			val1 = fetch_data_byte(emu, emu->x86.R_SI);
			val2 = fetch_byte(emu, emu->x86.R_ES, emu->x86.R_DI);
			cmp_byte(emu, val1, val2);
			emu->x86.R_CX -= 1;
			emu->x86.R_SI += inc;
			emu->x86.R_DI += inc;
			if (ACCESS_FLAG(F_ZF))
				break;	/* zero flag set means equal */
		}
		emu->x86.mode &= ~SYSMODE_PREFIX_REPNE;
	} else {
		val1 = fetch_data_byte(emu, emu->x86.R_SI);
		val2 = fetch_byte(emu, emu->x86.R_ES, emu->x86.R_DI);
		cmp_byte(emu, val1, val2);
		emu->x86.R_SI += inc;
		emu->x86.R_DI += inc;
	}
}
/****************************************************************************
REMARKS:
Handles opcode 0xa7
****************************************************************************/
static void
x86emuOp_cmps_word(struct X86EMU *emu)
{
	uint32_t val1, val2;
	int inc;

	if (emu->x86.mode & SYSMODE_PREFIX_DATA) {
		if (ACCESS_FLAG(F_DF))	/* down */
			inc = -4;
		else
			inc = 4;
	} else {
		if (ACCESS_FLAG(F_DF))	/* down */
			inc = -2;
		else
			inc = 2;
	}
	if (emu->x86.mode & SYSMODE_PREFIX_REPE) {
		/* REPE  */
		/* move them until CX is ZERO. */
		while (emu->x86.R_CX != 0) {
			if (emu->x86.mode & SYSMODE_PREFIX_DATA) {
				val1 = fetch_data_long(emu, emu->x86.R_SI);
				val2 = fetch_long(emu, emu->x86.R_ES, emu->x86.R_DI);
				cmp_long(emu, val1, val2);
			} else {
				val1 = fetch_data_word(emu, emu->x86.R_SI);
				val2 = fetch_word(emu, emu->x86.R_ES, emu->x86.R_DI);
				cmp_word(emu, (uint16_t) val1, (uint16_t) val2);
			}
			emu->x86.R_CX -= 1;
			emu->x86.R_SI += inc;
			emu->x86.R_DI += inc;
			if (ACCESS_FLAG(F_ZF) == 0)
				break;
		}
		emu->x86.mode &= ~SYSMODE_PREFIX_REPE;
	} else if (emu->x86.mode & SYSMODE_PREFIX_REPNE) {
		/* REPNE  */
		/* move them until CX is ZERO. */
		while (emu->x86.R_CX != 0) {
			if (emu->x86.mode & SYSMODE_PREFIX_DATA) {
				val1 = fetch_data_long(emu, emu->x86.R_SI);
				val2 = fetch_long(emu, emu->x86.R_ES, emu->x86.R_DI);
				cmp_long(emu, val1, val2);
			} else {
				val1 = fetch_data_word(emu, emu->x86.R_SI);
				val2 = fetch_word(emu, emu->x86.R_ES, emu->x86.R_DI);
				cmp_word(emu, (uint16_t) val1, (uint16_t) val2);
			}
			emu->x86.R_CX -= 1;
			emu->x86.R_SI += inc;
			emu->x86.R_DI += inc;
			if (ACCESS_FLAG(F_ZF))
				break;	/* zero flag set means equal */
		}
		emu->x86.mode &= ~SYSMODE_PREFIX_REPNE;
	} else {
		if (emu->x86.mode & SYSMODE_PREFIX_DATA) {
			val1 = fetch_data_long(emu, emu->x86.R_SI);
			val2 = fetch_long(emu, emu->x86.R_ES, emu->x86.R_DI);
			cmp_long(emu, val1, val2);
		} else {
			val1 = fetch_data_word(emu, emu->x86.R_SI);
			val2 = fetch_word(emu, emu->x86.R_ES, emu->x86.R_DI);
			cmp_word(emu, (uint16_t) val1, (uint16_t) val2);
		}
		emu->x86.R_SI += inc;
		emu->x86.R_DI += inc;
	}
}
/****************************************************************************
REMARKS:
Handles opcode 0xa9
****************************************************************************/
static void
x86emuOp_test_AX_IMM(struct X86EMU *emu)
{
	if (emu->x86.mode & SYSMODE_PREFIX_DATA) {
		test_long(emu, emu->x86.R_EAX, fetch_long_imm(emu));
	} else {
		test_word(emu, emu->x86.R_AX, fetch_word_imm(emu));
	}
}
/****************************************************************************
REMARKS:
Handles opcode 0xaa
****************************************************************************/
static void
x86emuOp_stos_byte(struct X86EMU *emu)
{
	int inc;

	if (ACCESS_FLAG(F_DF))	/* down */
		inc = -1;
	else
		inc = 1;
	if (emu->x86.mode & (SYSMODE_PREFIX_REPE | SYSMODE_PREFIX_REPNE)) {
		/* dont care whether REPE or REPNE */
		/* move them until CX is ZERO. */
		while (emu->x86.R_CX != 0) {
			store_byte(emu, emu->x86.R_ES, emu->x86.R_DI, emu->x86.R_AL);
			emu->x86.R_CX -= 1;
			emu->x86.R_DI += inc;
		}
		emu->x86.mode &= ~(SYSMODE_PREFIX_REPE | SYSMODE_PREFIX_REPNE);
	} else {
		store_byte(emu, emu->x86.R_ES, emu->x86.R_DI, emu->x86.R_AL);
		emu->x86.R_DI += inc;
	}
}
/****************************************************************************
REMARKS:
Handles opcode 0xab
****************************************************************************/
static void
x86emuOp_stos_word(struct X86EMU *emu)
{
	int inc;
	uint32_t count;

	if (emu->x86.mode & SYSMODE_PREFIX_DATA)
		inc = 4;
	else
		inc = 2;

	if (ACCESS_FLAG(F_DF))	/* down */
		inc = -inc;

	count = 1;
	if (emu->x86.mode & (SYSMODE_PREFIX_REPE | SYSMODE_PREFIX_REPNE)) {
		/* dont care whether REPE or REPNE */
		/* move them until CX is ZERO. */
		count = emu->x86.R_CX;
		emu->x86.R_CX = 0;
		emu->x86.mode &= ~(SYSMODE_PREFIX_REPE | SYSMODE_PREFIX_REPNE);
	}
	while (count--) {
		if (emu->x86.mode & SYSMODE_PREFIX_DATA) {
			store_long(emu, emu->x86.R_ES, emu->x86.R_DI, emu->x86.R_EAX);
		} else {
			store_word(emu, emu->x86.R_ES, emu->x86.R_DI, emu->x86.R_AX);
		}
		emu->x86.R_DI += inc;
	}
}
/****************************************************************************
REMARKS:
Handles opcode 0xac
****************************************************************************/
static void
x86emuOp_lods_byte(struct X86EMU *emu)
{
	int inc;

	if (ACCESS_FLAG(F_DF))	/* down */
		inc = -1;
	else
		inc = 1;
	if (emu->x86.mode & (SYSMODE_PREFIX_REPE | SYSMODE_PREFIX_REPNE)) {
		/* dont care whether REPE or REPNE */
		/* move them until CX is ZERO. */
		while (emu->x86.R_CX != 0) {
			emu->x86.R_AL = fetch_data_byte(emu, emu->x86.R_SI);
			emu->x86.R_CX -= 1;
			emu->x86.R_SI += inc;
		}
		emu->x86.mode &= ~(SYSMODE_PREFIX_REPE | SYSMODE_PREFIX_REPNE);
	} else {
		emu->x86.R_AL = fetch_data_byte(emu, emu->x86.R_SI);
		emu->x86.R_SI += inc;
	}
}
/****************************************************************************
REMARKS:
Handles opcode 0xad
****************************************************************************/
static void
x86emuOp_lods_word(struct X86EMU *emu)
{
	int inc;
	uint32_t count;

	if (emu->x86.mode & SYSMODE_PREFIX_DATA)
		inc = 4;
	else
		inc = 2;

	if (ACCESS_FLAG(F_DF))	/* down */
		inc = -inc;

	count = 1;
	if (emu->x86.mode & (SYSMODE_PREFIX_REPE | SYSMODE_PREFIX_REPNE)) {
		/* dont care whether REPE or REPNE */
		/* move them until CX is ZERO. */
		count = emu->x86.R_CX;
		emu->x86.R_CX = 0;
		emu->x86.mode &= ~(SYSMODE_PREFIX_REPE | SYSMODE_PREFIX_REPNE);
	}
	while (count--) {
		if (emu->x86.mode & SYSMODE_PREFIX_DATA) {
			emu->x86.R_EAX = fetch_data_long(emu, emu->x86.R_SI);
		} else {
			emu->x86.R_AX = fetch_data_word(emu, emu->x86.R_SI);
		}
		emu->x86.R_SI += inc;
	}
}
/****************************************************************************
REMARKS:
Handles opcode 0xae
****************************************************************************/
static void
x86emuOp_scas_byte(struct X86EMU *emu)
{
	int8_t val2;
	int inc;

	if (ACCESS_FLAG(F_DF))	/* down */
		inc = -1;
	else
		inc = 1;
	if (emu->x86.mode & SYSMODE_PREFIX_REPE) {
		/* REPE  */
		/* move them until CX is ZERO. */
		while (emu->x86.R_CX != 0) {
			val2 = fetch_byte(emu, emu->x86.R_ES, emu->x86.R_DI);
			cmp_byte(emu, emu->x86.R_AL, val2);
			emu->x86.R_CX -= 1;
			emu->x86.R_DI += inc;
			if (ACCESS_FLAG(F_ZF) == 0)
				break;
		}
		emu->x86.mode &= ~SYSMODE_PREFIX_REPE;
	} else if (emu->x86.mode & SYSMODE_PREFIX_REPNE) {
		/* REPNE  */
		/* move them until CX is ZERO. */
		while (emu->x86.R_CX != 0) {
			val2 = fetch_byte(emu, emu->x86.R_ES, emu->x86.R_DI);
			cmp_byte(emu, emu->x86.R_AL, val2);
			emu->x86.R_CX -= 1;
			emu->x86.R_DI += inc;
			if (ACCESS_FLAG(F_ZF))
				break;	/* zero flag set means equal */
		}
		emu->x86.mode &= ~SYSMODE_PREFIX_REPNE;
	} else {
		val2 = fetch_byte(emu, emu->x86.R_ES, emu->x86.R_DI);
		cmp_byte(emu, emu->x86.R_AL, val2);
		emu->x86.R_DI += inc;
	}
}
/****************************************************************************
REMARKS:
Handles opcode 0xaf
****************************************************************************/
static void
x86emuOp_scas_word(struct X86EMU *emu)
{
	int inc;
	uint32_t val;

	if (emu->x86.mode & SYSMODE_PREFIX_DATA)
		inc = 4;
	else
		inc = 2;

	if (ACCESS_FLAG(F_DF))	/* down */
		inc = -inc;

	if (emu->x86.mode & SYSMODE_PREFIX_REPE) {
		/* REPE  */
		/* move them until CX is ZERO. */
		while (emu->x86.R_CX != 0) {
			if (emu->x86.mode & SYSMODE_PREFIX_DATA) {
				val = fetch_long(emu, emu->x86.R_ES, emu->x86.R_DI);
				cmp_long(emu, emu->x86.R_EAX, val);
			} else {
				val = fetch_word(emu, emu->x86.R_ES, emu->x86.R_DI);
				cmp_word(emu, emu->x86.R_AX, (uint16_t) val);
			}
			emu->x86.R_CX -= 1;
			emu->x86.R_DI += inc;
			if (ACCESS_FLAG(F_ZF) == 0)
				break;
		}
		emu->x86.mode &= ~SYSMODE_PREFIX_REPE;
	} else if (emu->x86.mode & SYSMODE_PREFIX_REPNE) {
		/* REPNE  */
		/* move them until CX is ZERO. */
		while (emu->x86.R_CX != 0) {
			if (emu->x86.mode & SYSMODE_PREFIX_DATA) {
				val = fetch_long(emu, emu->x86.R_ES, emu->x86.R_DI);
				cmp_long(emu, emu->x86.R_EAX, val);
			} else {
				val = fetch_word(emu, emu->x86.R_ES, emu->x86.R_DI);
				cmp_word(emu, emu->x86.R_AX, (uint16_t) val);
			}
			emu->x86.R_CX -= 1;
			emu->x86.R_DI += inc;
			if (ACCESS_FLAG(F_ZF))
				break;	/* zero flag set means equal */
		}
		emu->x86.mode &= ~SYSMODE_PREFIX_REPNE;
	} else {
		if (emu->x86.mode & SYSMODE_PREFIX_DATA) {
			val = fetch_long(emu, emu->x86.R_ES, emu->x86.R_DI);
			cmp_long(emu, emu->x86.R_EAX, val);
		} else {
			val = fetch_word(emu, emu->x86.R_ES, emu->x86.R_DI);
			cmp_word(emu, emu->x86.R_AX, (uint16_t) val);
		}
		emu->x86.R_DI += inc;
	}
}
/****************************************************************************
REMARKS:
Handles opcode 0xb8
****************************************************************************/
static void
x86emuOp_mov_word_AX_IMM(struct X86EMU *emu)
{
	if (emu->x86.mode & SYSMODE_PREFIX_DATA)
		emu->x86.R_EAX = fetch_long_imm(emu);
	else
		emu->x86.R_AX = fetch_word_imm(emu);
}
/****************************************************************************
REMARKS:
Handles opcode 0xb9
****************************************************************************/
static void
x86emuOp_mov_word_CX_IMM(struct X86EMU *emu)
{
	if (emu->x86.mode & SYSMODE_PREFIX_DATA)
		emu->x86.R_ECX = fetch_long_imm(emu);
	else
		emu->x86.R_CX = fetch_word_imm(emu);
}
/****************************************************************************
REMARKS:
Handles opcode 0xba
****************************************************************************/
static void
x86emuOp_mov_word_DX_IMM(struct X86EMU *emu)
{
	if (emu->x86.mode & SYSMODE_PREFIX_DATA)
		emu->x86.R_EDX = fetch_long_imm(emu);
	else
		emu->x86.R_DX = fetch_word_imm(emu);
}
/****************************************************************************
REMARKS:
Handles opcode 0xbb
****************************************************************************/
static void
x86emuOp_mov_word_BX_IMM(struct X86EMU *emu)
{
	if (emu->x86.mode & SYSMODE_PREFIX_DATA)
		emu->x86.R_EBX = fetch_long_imm(emu);
	else
		emu->x86.R_BX = fetch_word_imm(emu);
}
/****************************************************************************
REMARKS:
Handles opcode 0xbc
****************************************************************************/
static void
x86emuOp_mov_word_SP_IMM(struct X86EMU *emu)
{
	if (emu->x86.mode & SYSMODE_PREFIX_DATA)
		emu->x86.R_ESP = fetch_long_imm(emu);
	else
		emu->x86.R_SP = fetch_word_imm(emu);
}
/****************************************************************************
REMARKS:
Handles opcode 0xbd
****************************************************************************/
static void
x86emuOp_mov_word_BP_IMM(struct X86EMU *emu)
{
	if (emu->x86.mode & SYSMODE_PREFIX_DATA)
		emu->x86.R_EBP = fetch_long_imm(emu);
	else
		emu->x86.R_BP = fetch_word_imm(emu);
}
/****************************************************************************
REMARKS:
Handles opcode 0xbe
****************************************************************************/
static void
x86emuOp_mov_word_SI_IMM(struct X86EMU *emu)
{
	if (emu->x86.mode & SYSMODE_PREFIX_DATA)
		emu->x86.R_ESI = fetch_long_imm(emu);
	else
		emu->x86.R_SI = fetch_word_imm(emu);
}
/****************************************************************************
REMARKS:
Handles opcode 0xbf
****************************************************************************/
static void
x86emuOp_mov_word_DI_IMM(struct X86EMU *emu)
{
	if (emu->x86.mode & SYSMODE_PREFIX_DATA)
		emu->x86.R_EDI = fetch_long_imm(emu);
	else
		emu->x86.R_DI = fetch_word_imm(emu);
}
/* used by opcodes c0, d0, and d2. */
static
uint8_t(* const opcD0_byte_operation[]) (struct X86EMU *, uint8_t d, uint8_t s) =
{
	rol_byte,
	ror_byte,
	rcl_byte,
	rcr_byte,
	shl_byte,
	shr_byte,
	shl_byte,		/* sal_byte === shl_byte  by definition */
	sar_byte,
};
/****************************************************************************
REMARKS:
Handles opcode 0xc0
****************************************************************************/
static void
x86emuOp_opcC0_byte_RM_MEM(struct X86EMU *emu)
{
	uint8_t destval, amt;

	/*
         * Yet another weirdo special case instruction format.  Part of
         * the opcode held below in "RH".  Doubly nested case would
         * result, except that the decoded instruction
         */
	fetch_decode_modrm(emu);
	/* know operation, decode the mod byte to find the addressing mode. */
	destval = decode_and_fetch_byte_imm8(emu, &amt);
	destval = (*opcD0_byte_operation[emu->cur_rh]) (emu, destval, amt);
	write_back_byte(emu, destval);
}
/* used by opcodes c1, d1, and d3. */
static
uint16_t(* const opcD1_word_operation[]) (struct X86EMU *, uint16_t s, uint8_t d) =
{
	rol_word,
	ror_word,
	rcl_word,
	rcr_word,
	shl_word,
	shr_word,
	shl_word,		/* sal_byte === shl_byte  by definition */
	sar_word,
};
/* used by opcodes c1, d1, and d3. */
static
uint32_t(* const opcD1_long_operation[]) (struct X86EMU *, uint32_t s, uint8_t d) =
{
	rol_long,
	ror_long,
	rcl_long,
	rcr_long,
	shl_long,
	shr_long,
	shl_long,		/* sal_byte === shl_byte  by definition */
	sar_long,
};
/****************************************************************************
REMARKS:
Handles opcode 0xc1
****************************************************************************/
static void
x86emuOp_opcC1_word_RM_MEM(struct X86EMU *emu)
{
	uint8_t amt;

	/*
         * Yet another weirdo special case instruction format.  Part of
         * the opcode held below in "RH".  Doubly nested case would
         * result, except that the decoded instruction
         */
	fetch_decode_modrm(emu);
	if (emu->x86.mode & SYSMODE_PREFIX_DATA) {
		uint32_t destval;

		destval = decode_and_fetch_long_imm8(emu, &amt);
		destval = (*opcD1_long_operation[emu->cur_rh]) (emu, destval, amt);
		write_back_long(emu, destval);
	} else {
		uint16_t destval;

		destval = decode_and_fetch_word_imm8(emu, &amt);
		destval = (*opcD1_word_operation[emu->cur_rh]) (emu, destval, amt);
		write_back_word(emu, destval);
	}
}
/****************************************************************************
REMARKS:
Handles opcode 0xc2
****************************************************************************/
static void
x86emuOp_ret_near_IMM(struct X86EMU *emu)
{
	uint16_t imm;

	imm = fetch_word_imm(emu);
	emu->x86.R_IP = pop_word(emu);
	emu->x86.R_SP += imm;
}
/****************************************************************************
REMARKS:
Handles opcode 0xc6
****************************************************************************/
static void
x86emuOp_mov_byte_RM_IMM(struct X86EMU *emu)
{
	uint8_t *destreg;
	uint32_t destoffset;
	uint8_t imm;

	fetch_decode_modrm(emu);
	if (emu->cur_rh != 0)
		X86EMU_halt_sys(emu);
	if (emu->cur_mod != 3) {
		destoffset = decode_rl_address(emu);
		imm = fetch_byte_imm(emu);
		store_data_byte(emu, destoffset, imm);
	} else {
		destreg = decode_rl_byte_register(emu);
		imm = fetch_byte_imm(emu);
		*destreg = imm;
	}
}
/****************************************************************************
REMARKS:
Handles opcode 0xc7
****************************************************************************/
static void
x86emuOp32_mov_word_RM_IMM(struct X86EMU *emu)
{
	uint32_t destoffset;
	uint32_t imm, *destreg;

	fetch_decode_modrm(emu);
	if (emu->cur_rh != 0)
		X86EMU_halt_sys(emu);

	if (emu->cur_mod != 3) {
		destoffset = decode_rl_address(emu);
		imm = fetch_long_imm(emu);
		store_data_long(emu, destoffset, imm);
	} else {
		destreg = decode_rl_long_register(emu);
		imm = fetch_long_imm(emu);
		*destreg = imm;
	}
}

static void
x86emuOp16_mov_word_RM_IMM(struct X86EMU *emu)
{
	uint32_t destoffset;
	uint16_t imm, *destreg;

	fetch_decode_modrm(emu);
	if (emu->cur_rh != 0)
		X86EMU_halt_sys(emu);

	if (emu->cur_mod != 3) {
		destoffset = decode_rl_address(emu);
		imm = fetch_word_imm(emu);
		store_data_word(emu, destoffset, imm);
	} else {
		destreg = decode_rl_word_register(emu);
		imm = fetch_word_imm(emu);
		*destreg = imm;
	}
}

static void
x86emuOp_mov_word_RM_IMM(struct X86EMU *emu)
{
	if (emu->x86.mode & SYSMODE_PREFIX_DATA)
		x86emuOp32_mov_word_RM_IMM(emu);
	else
		x86emuOp16_mov_word_RM_IMM(emu);
}
/****************************************************************************
REMARKS:
Handles opcode 0xc8
****************************************************************************/
static void
x86emuOp_enter(struct X86EMU *emu)
{
	uint16_t local, frame_pointer;
	uint8_t nesting;
	int i;

	local = fetch_word_imm(emu);
	nesting = fetch_byte_imm(emu);
	push_word(emu, emu->x86.R_BP);
	frame_pointer = emu->x86.R_SP;
	if (nesting > 0) {
		for (i = 1; i < nesting; i++) {
			emu->x86.R_BP -= 2;
			push_word(emu, fetch_word(emu, emu->x86.R_SS, emu->x86.R_BP));
		}
		push_word(emu, frame_pointer);
	}
	emu->x86.R_BP = frame_pointer;
	emu->x86.R_SP = (uint16_t) (emu->x86.R_SP - local);
}
/****************************************************************************
REMARKS:
Handles opcode 0xc9
****************************************************************************/
static void
x86emuOp_leave(struct X86EMU *emu)
{
	emu->x86.R_SP = emu->x86.R_BP;
	emu->x86.R_BP = pop_word(emu);
}
/****************************************************************************
REMARKS:
Handles opcode 0xca
****************************************************************************/
static void
x86emuOp_ret_far_IMM(struct X86EMU *emu)
{
	uint16_t imm;

	imm = fetch_word_imm(emu);
	emu->x86.R_IP = pop_word(emu);
	emu->x86.R_CS = pop_word(emu);
	emu->x86.R_SP += imm;
}
/****************************************************************************
REMARKS:
Handles opcode 0xcb
****************************************************************************/
static void
x86emuOp_ret_far(struct X86EMU *emu)
{
	emu->x86.R_IP = pop_word(emu);
	emu->x86.R_CS = pop_word(emu);
}
/****************************************************************************
REMARKS:
Handles opcode 0xcc
****************************************************************************/
static void
x86emuOp_int3(struct X86EMU *emu)
{
	x86emu_intr_dispatch(emu, 3);
}
/****************************************************************************
REMARKS:
Handles opcode 0xcd
****************************************************************************/
static void
x86emuOp_int_IMM(struct X86EMU *emu)
{
	uint8_t intnum;

	intnum = fetch_byte_imm(emu);
	x86emu_intr_dispatch(emu, intnum);
}
/****************************************************************************
REMARKS:
Handles opcode 0xce
****************************************************************************/
static void
x86emuOp_into(struct X86EMU *emu)
{
	if (ACCESS_FLAG(F_OF))
		x86emu_intr_dispatch(emu, 4);
}
/****************************************************************************
REMARKS:
Handles opcode 0xcf
****************************************************************************/
static void
x86emuOp_iret(struct X86EMU *emu)
{
	emu->x86.R_IP = pop_word(emu);
	emu->x86.R_CS = pop_word(emu);
	emu->x86.R_FLG = pop_word(emu);
}
/****************************************************************************
REMARKS:
Handles opcode 0xd0
****************************************************************************/
static void
x86emuOp_opcD0_byte_RM_1(struct X86EMU *emu)
{
	uint8_t destval;

	fetch_decode_modrm(emu);
	destval = decode_and_fetch_byte(emu);
	destval = (*opcD0_byte_operation[emu->cur_rh]) (emu, destval, 1);
	write_back_byte(emu, destval);
}
/****************************************************************************
REMARKS:
Handles opcode 0xd1
****************************************************************************/
static void
x86emuOp_opcD1_word_RM_1(struct X86EMU *emu)
{
	if (emu->x86.mode & SYSMODE_PREFIX_DATA) {
		uint32_t destval;

		fetch_decode_modrm(emu);
		destval = decode_and_fetch_long(emu);
		destval = (*opcD1_long_operation[emu->cur_rh]) (emu, destval, 1);
		write_back_long(emu, destval);
	} else {
		uint16_t destval;

		fetch_decode_modrm(emu);
		destval = decode_and_fetch_word(emu);
		destval = (*opcD1_word_operation[emu->cur_rh]) (emu, destval, 1);
		write_back_word(emu, destval);
	}
}
/****************************************************************************
REMARKS:
Handles opcode 0xd2
****************************************************************************/
static void
x86emuOp_opcD2_byte_RM_CL(struct X86EMU *emu)
{
	uint8_t destval;

	fetch_decode_modrm(emu);
	destval = decode_and_fetch_byte(emu);
	destval = (*opcD0_byte_operation[emu->cur_rh]) (emu, destval, emu->x86.R_CL);
	write_back_byte(emu, destval);
}
/****************************************************************************
REMARKS:
Handles opcode 0xd3
****************************************************************************/
static void
x86emuOp_opcD3_word_RM_CL(struct X86EMU *emu)
{
	if (emu->x86.mode & SYSMODE_PREFIX_DATA) {
		uint32_t destval;

		fetch_decode_modrm(emu);
		destval = decode_and_fetch_long(emu);
		destval = (*opcD1_long_operation[emu->cur_rh]) (emu, destval, emu->x86.R_CL);
		write_back_long(emu, destval);
	} else {
		uint16_t destval;

		fetch_decode_modrm(emu);
		destval = decode_and_fetch_word(emu);
		destval = (*opcD1_word_operation[emu->cur_rh]) (emu, destval, emu->x86.R_CL);
		write_back_word(emu, destval);
	}
}
/****************************************************************************
REMARKS:
Handles opcode 0xd4
****************************************************************************/
static void
x86emuOp_aam(struct X86EMU *emu)
{
	uint8_t a;

	a = fetch_byte_imm(emu);	/* this is a stupid encoding. */
	if (a != 10) {
		/* fix: add base decoding aam_word(uint8_t val, int base a) */
		X86EMU_halt_sys(emu);
	}
	/* note the type change here --- returning AL and AH in AX. */
	emu->x86.R_AX = aam_word(emu, emu->x86.R_AL);
}
/****************************************************************************
REMARKS:
Handles opcode 0xd5
****************************************************************************/
static void
x86emuOp_aad(struct X86EMU *emu)
{
	uint8_t a;

	a = fetch_byte_imm(emu);
	if (a != 10) {
		/* fix: add base decoding aad_word(uint16_t val, int base a) */
		X86EMU_halt_sys(emu);
	}
	emu->x86.R_AX = aad_word(emu, emu->x86.R_AX);
}
/* opcode 0xd6 ILLEGAL OPCODE */

/****************************************************************************
REMARKS:
Handles opcode 0xd7
****************************************************************************/
static void
x86emuOp_xlat(struct X86EMU *emu)
{
	uint16_t addr;

	addr = (uint16_t) (emu->x86.R_BX + (uint8_t) emu->x86.R_AL);
	emu->x86.R_AL = fetch_data_byte(emu, addr);
}

/* opcode=0xd8 */
static void
x86emuOp_esc_coprocess_d8(struct X86EMU *emu)
{
}
/* opcode=0xd9 */
static void
x86emuOp_esc_coprocess_d9(struct X86EMU *emu)
{
	fetch_decode_modrm(emu);
	if (emu->cur_mod != 3)
		decode_rl_address(emu);
}
/* opcode=0xda */
static void
x86emuOp_esc_coprocess_da(struct X86EMU *emu)
{
	fetch_decode_modrm(emu);
	if (emu->cur_mod != 3)
		decode_rl_address(emu);
}
/* opcode=0xdb */
static void
x86emuOp_esc_coprocess_db(struct X86EMU *emu)
{
	fetch_decode_modrm(emu);
	if (emu->cur_mod != 3)
		decode_rl_address(emu);
}
/* opcode=0xdc */
static void
x86emuOp_esc_coprocess_dc(struct X86EMU *emu)
{
	fetch_decode_modrm(emu);
	if (emu->cur_mod != 3)
		decode_rl_address(emu);
}
/* opcode=0xdd */
static void
x86emuOp_esc_coprocess_dd(struct X86EMU *emu)
{
	fetch_decode_modrm(emu);
	if (emu->cur_mod != 3)
		decode_rl_address(emu);
}
/* opcode=0xde */
static void
x86emuOp_esc_coprocess_de(struct X86EMU *emu)
{
	fetch_decode_modrm(emu);
	if (emu->cur_mod != 3)
		decode_rl_address(emu);
}
/* opcode=0xdf */
static void
x86emuOp_esc_coprocess_df(struct X86EMU *emu)
{
	fetch_decode_modrm(emu);
	if (emu->cur_mod != 3)
		decode_rl_address(emu);
}

/****************************************************************************
REMARKS:
Handles opcode 0xe0
****************************************************************************/
static void
x86emuOp_loopne(struct X86EMU *emu)
{
	int16_t ip;

	ip = (int8_t) fetch_byte_imm(emu);
	ip += (int16_t) emu->x86.R_IP;
	emu->x86.R_CX -= 1;
	if (emu->x86.R_CX != 0 && !ACCESS_FLAG(F_ZF))	/* CX != 0 and !ZF */
		emu->x86.R_IP = ip;
}
/****************************************************************************
REMARKS:
Handles opcode 0xe1
****************************************************************************/
static void
x86emuOp_loope(struct X86EMU *emu)
{
	int16_t ip;

	ip = (int8_t) fetch_byte_imm(emu);
	ip += (int16_t) emu->x86.R_IP;
	emu->x86.R_CX -= 1;
	if (emu->x86.R_CX != 0 && ACCESS_FLAG(F_ZF))	/* CX != 0 and ZF */
		emu->x86.R_IP = ip;
}
/****************************************************************************
REMARKS:
Handles opcode 0xe2
****************************************************************************/
static void
x86emuOp_loop(struct X86EMU *emu)
{
	int16_t ip;

	ip = (int8_t) fetch_byte_imm(emu);
	ip += (int16_t) emu->x86.R_IP;
	emu->x86.R_CX -= 1;
	if (emu->x86.R_CX != 0)
		emu->x86.R_IP = ip;
}
/****************************************************************************
REMARKS:
Handles opcode 0xe3
****************************************************************************/
static void
x86emuOp_jcxz(struct X86EMU *emu)
{
	uint16_t target;
	int8_t offset;

	/* jump to byte offset if overflow flag is set */
	offset = (int8_t) fetch_byte_imm(emu);
	target = (uint16_t) (emu->x86.R_IP + offset);
	if (emu->x86.R_CX == 0)
		emu->x86.R_IP = target;
}
/****************************************************************************
REMARKS:
Handles opcode 0xe4
****************************************************************************/
static void
x86emuOp_in_byte_AL_IMM(struct X86EMU *emu)
{
	uint8_t port;

	port = (uint8_t) fetch_byte_imm(emu);
	emu->x86.R_AL = (*emu->emu_inb) (emu, port);
}
/****************************************************************************
REMARKS:
Handles opcode 0xe5
****************************************************************************/
static void
x86emuOp_in_word_AX_IMM(struct X86EMU *emu)
{
	uint8_t port;

	port = (uint8_t) fetch_byte_imm(emu);
	if (emu->x86.mode & SYSMODE_PREFIX_DATA) {
		emu->x86.R_EAX = (*emu->emu_inl) (emu, port);
	} else {
		emu->x86.R_AX = (*emu->emu_inw) (emu, port);
	}
}
/****************************************************************************
REMARKS:
Handles opcode 0xe6
****************************************************************************/
static void
x86emuOp_out_byte_IMM_AL(struct X86EMU *emu)
{
	uint8_t port;

	port = (uint8_t) fetch_byte_imm(emu);
	(*emu->emu_outb) (emu, port, emu->x86.R_AL);
}
/****************************************************************************
REMARKS:
Handles opcode 0xe7
****************************************************************************/
static void
x86emuOp_out_word_IMM_AX(struct X86EMU *emu)
{
	uint8_t port;

	port = (uint8_t) fetch_byte_imm(emu);
	if (emu->x86.mode & SYSMODE_PREFIX_DATA) {
		(*emu->emu_outl) (emu, port, emu->x86.R_EAX);
	} else {
		(*emu->emu_outw) (emu, port, emu->x86.R_AX);
	}
}
/****************************************************************************
REMARKS:
Handles opcode 0xe8
****************************************************************************/
static void
x86emuOp_call_near_IMM(struct X86EMU *emu)
{
	int16_t ip;

	ip = (int16_t) fetch_word_imm(emu);
	ip += (int16_t) emu->x86.R_IP;	/* CHECK SIGN */
	push_word(emu, emu->x86.R_IP);
	emu->x86.R_IP = ip;
}
/****************************************************************************
REMARKS:
Handles opcode 0xe9
****************************************************************************/
static void
x86emuOp_jump_near_IMM(struct X86EMU *emu)
{
	int ip;

	ip = (int16_t) fetch_word_imm(emu);
	ip += (int16_t) emu->x86.R_IP;
	emu->x86.R_IP = (uint16_t) ip;
}
/****************************************************************************
REMARKS:
Handles opcode 0xea
****************************************************************************/
static void
x86emuOp_jump_far_IMM(struct X86EMU *emu)
{
	uint16_t cs, ip;

	ip = fetch_word_imm(emu);
	cs = fetch_word_imm(emu);
	emu->x86.R_IP = ip;
	emu->x86.R_CS = cs;
}
/****************************************************************************
REMARKS:
Handles opcode 0xeb
****************************************************************************/
static void
x86emuOp_jump_byte_IMM(struct X86EMU *emu)
{
	uint16_t target;
	int8_t offset;

	offset = (int8_t) fetch_byte_imm(emu);
	target = (uint16_t) (emu->x86.R_IP + offset);
	emu->x86.R_IP = target;
}
/****************************************************************************
REMARKS:
Handles opcode 0xec
****************************************************************************/
static void
x86emuOp_in_byte_AL_DX(struct X86EMU *emu)
{
	emu->x86.R_AL = (*emu->emu_inb) (emu, emu->x86.R_DX);
}
/****************************************************************************
REMARKS:
Handles opcode 0xed
****************************************************************************/
static void
x86emuOp_in_word_AX_DX(struct X86EMU *emu)
{
	if (emu->x86.mode & SYSMODE_PREFIX_DATA) {
		emu->x86.R_EAX = (*emu->emu_inl) (emu, emu->x86.R_DX);
	} else {
		emu->x86.R_AX = (*emu->emu_inw) (emu, emu->x86.R_DX);
	}
}
/****************************************************************************
REMARKS:
Handles opcode 0xee
****************************************************************************/
static void
x86emuOp_out_byte_DX_AL(struct X86EMU *emu)
{
	(*emu->emu_outb) (emu, emu->x86.R_DX, emu->x86.R_AL);
}
/****************************************************************************
REMARKS:
Handles opcode 0xef
****************************************************************************/
static void
x86emuOp_out_word_DX_AX(struct X86EMU *emu)
{
	if (emu->x86.mode & SYSMODE_PREFIX_DATA) {
		(*emu->emu_outl) (emu, emu->x86.R_DX, emu->x86.R_EAX);
	} else {
		(*emu->emu_outw) (emu, emu->x86.R_DX, emu->x86.R_AX);
	}
}
/****************************************************************************
REMARKS:
Handles opcode 0xf0
****************************************************************************/
static void
x86emuOp_lock(struct X86EMU *emu)
{
}
/*opcode 0xf1 ILLEGAL OPERATION */

/****************************************************************************
REMARKS:
Handles opcode 0xf5
****************************************************************************/
static void
x86emuOp_cmc(struct X86EMU *emu)
{
	if (ACCESS_FLAG(F_CF))
		CLEAR_FLAG(F_CF);
	else
		SET_FLAG(F_CF);
}
/****************************************************************************
REMARKS:
Handles opcode 0xf6
****************************************************************************/
static void
x86emuOp_opcF6_byte_RM(struct X86EMU *emu)
{
	uint8_t destval, srcval;

	/* long, drawn out code follows.  Double switch for a total of 32
	 * cases.  */
	fetch_decode_modrm(emu);
	if (emu->cur_rh == 1)
		X86EMU_halt_sys(emu);

	if (emu->cur_rh == 0) {
		destval = decode_and_fetch_byte_imm8(emu, &srcval);
		test_byte(emu, destval, srcval);
		return;
	}
	destval = decode_and_fetch_byte(emu);
	switch (emu->cur_rh) {
	case 2:
		destval = ~destval;
		write_back_byte(emu, destval);
		break;
	case 3:
		destval = neg_byte(emu, destval);
		write_back_byte(emu, destval);
		break;
	case 4:
		mul_byte(emu, destval);
		break;
	case 5:
		imul_byte(emu, destval);
		break;
	case 6:
		div_byte(emu, destval);
		break;
	case 7:
		idiv_byte(emu, destval);
		break;
	}
}
/****************************************************************************
REMARKS:
Handles opcode 0xf7
****************************************************************************/
static void
x86emuOp32_opcF7_word_RM(struct X86EMU *emu)
{
	uint32_t destval, srcval;

	/* long, drawn out code follows.  Double switch for a total of 32
	 * cases.  */
	fetch_decode_modrm(emu);
	if (emu->cur_rh == 1)
		X86EMU_halt_sys(emu);

	if (emu->cur_rh == 0) {
		if (emu->cur_mod != 3) {
			uint32_t destoffset;

			destoffset = decode_rl_address(emu);
			srcval = fetch_long_imm(emu);
			destval = fetch_data_long(emu, destoffset);
		} else {
			srcval = fetch_long_imm(emu);
			destval = *decode_rl_long_register(emu);
		}
		test_long(emu, destval, srcval);
		return;
	}
	destval = decode_and_fetch_long(emu);
	switch (emu->cur_rh) {
	case 2:
		destval = ~destval;
		write_back_long(emu, destval);
		break;
	case 3:
		destval = neg_long(emu, destval);
		write_back_long(emu, destval);
		break;
	case 4:
		mul_long(emu, destval);
		break;
	case 5:
		imul_long(emu, destval);
		break;
	case 6:
		div_long(emu, destval);
		break;
	case 7:
		idiv_long(emu, destval);
		break;
	}
}
static void
x86emuOp16_opcF7_word_RM(struct X86EMU *emu)
{
	uint16_t destval, srcval;

	/* long, drawn out code follows.  Double switch for a total of 32
	 * cases.  */
	fetch_decode_modrm(emu);
	if (emu->cur_rh == 1)
		X86EMU_halt_sys(emu);

	if (emu->cur_rh == 0) {
		if (emu->cur_mod != 3) {
			uint32_t destoffset;

			destoffset = decode_rl_address(emu);
			srcval = fetch_word_imm(emu);
			destval = fetch_data_word(emu, destoffset);
		} else {
			srcval = fetch_word_imm(emu);
			destval = *decode_rl_word_register(emu);
		}
		test_word(emu, destval, srcval);
		return;
	}
	destval = decode_and_fetch_word(emu);
	switch (emu->cur_rh) {
	case 2:
		destval = ~destval;
		write_back_word(emu, destval);
		break;
	case 3:
		destval = neg_word(emu, destval);
		write_back_word(emu, destval);
		break;
	case 4:
		mul_word(emu, destval);
		break;
	case 5:
		imul_word(emu, destval);
		break;
	case 6:
		div_word(emu, destval);
		break;
	case 7:
		idiv_word(emu, destval);
		break;
	}
}
static void
x86emuOp_opcF7_word_RM(struct X86EMU *emu)
{
	if (emu->x86.mode & SYSMODE_PREFIX_DATA)
		x86emuOp32_opcF7_word_RM(emu);
	else
		x86emuOp16_opcF7_word_RM(emu);
}
/****************************************************************************
REMARKS:
Handles opcode 0xfe
****************************************************************************/
static void
x86emuOp_opcFE_byte_RM(struct X86EMU *emu)
{
	uint8_t destval;
	uint32_t destoffset;
	uint8_t *destreg;

	/* Yet another special case instruction. */
	fetch_decode_modrm(emu);
	if (emu->cur_mod != 3) {
		destoffset = decode_rl_address(emu);
		switch (emu->cur_rh) {
		case 0:	/* inc word ptr ... */
			destval = fetch_data_byte(emu, destoffset);
			destval = inc_byte(emu, destval);
			store_data_byte(emu, destoffset, destval);
			break;
		case 1:	/* dec word ptr ... */
			destval = fetch_data_byte(emu, destoffset);
			destval = dec_byte(emu, destval);
			store_data_byte(emu, destoffset, destval);
			break;
		}
	} else {
		destreg = decode_rl_byte_register(emu);
		switch (emu->cur_rh) {
		case 0:
			*destreg = inc_byte(emu, *destreg);
			break;
		case 1:
			*destreg = dec_byte(emu, *destreg);
			break;
		}
	}
}
/****************************************************************************
REMARKS:
Handles opcode 0xff
****************************************************************************/
static void
x86emuOp32_opcFF_word_RM(struct X86EMU *emu)
{
	uint32_t destoffset = 0;
	uint32_t destval, *destreg;

	if (emu->cur_mod != 3) {
		destoffset = decode_rl_address(emu);
		destval = fetch_data_long(emu, destoffset);
		switch (emu->cur_rh) {
		case 0:	/* inc word ptr ... */
			destval = inc_long(emu, destval);
			store_data_long(emu, destoffset, destval);
			break;
		case 1:	/* dec word ptr ... */
			destval = dec_long(emu, destval);
			store_data_long(emu, destoffset, destval);
			break;
		case 6:	/* push word ptr ... */
			push_long(emu, destval);
			break;
		}
	} else {
		destreg = decode_rl_long_register(emu);
		switch (emu->cur_rh) {
		case 0:
			*destreg = inc_long(emu, *destreg);
			break;
		case 1:
			*destreg = dec_long(emu, *destreg);
			break;
		case 6:
			push_long(emu, *destreg);
			break;
		}
	}
}

static void
x86emuOp16_opcFF_word_RM(struct X86EMU *emu)
{
	uint32_t destoffset = 0;
	uint16_t *destreg;
	uint16_t destval;

	if (emu->cur_mod != 3) {
		destoffset = decode_rl_address(emu);
		destval = fetch_data_word(emu, destoffset);
		switch (emu->cur_rh) {
		case 0:
			destval = inc_word(emu, destval);
			store_data_word(emu, destoffset, destval);
			break;
		case 1:	/* dec word ptr ... */
			destval = dec_word(emu, destval);
			store_data_word(emu, destoffset, destval);
			break;
		case 6:	/* push word ptr ... */
			push_word(emu, destval);
			break;
		}
	} else {
		destreg = decode_rl_word_register(emu);
		switch (emu->cur_rh) {
		case 0:
			*destreg = inc_word(emu, *destreg);
			break;
		case 1:
			*destreg = dec_word(emu, *destreg);
			break;
		case 6:
			push_word(emu, *destreg);
			break;
		}
	}
}

static void
x86emuOp_opcFF_word_RM(struct X86EMU *emu)
{
	uint32_t destoffset = 0;
	uint16_t destval, destval2;

	/* Yet another special case instruction. */
	fetch_decode_modrm(emu);
	if ((emu->cur_mod == 3 && (emu->cur_rh == 3 || emu->cur_rh == 5)) || emu->cur_rh == 7)
		X86EMU_halt_sys(emu);
	if (emu->cur_rh == 0 || emu->cur_rh == 1 || emu->cur_rh == 6) {
		if (emu->x86.mode & SYSMODE_PREFIX_DATA)
			x86emuOp32_opcFF_word_RM(emu);
		else
			x86emuOp16_opcFF_word_RM(emu);
		return;
	}

	if (emu->cur_mod != 3) {
		destoffset = decode_rl_address(emu);
		destval = fetch_data_word(emu, destoffset);
		switch (emu->cur_rh) {
		case 3:	/* call far ptr ... */
			destval2 = fetch_data_word(emu, destoffset + 2);
			push_word(emu, emu->x86.R_CS);
			emu->x86.R_CS = destval2;
			push_word(emu, emu->x86.R_IP);
			emu->x86.R_IP = destval;
			break;
		case 5:	/* jmp far ptr ... */
			destval2 = fetch_data_word(emu, destoffset + 2);
			emu->x86.R_IP = destval;
			emu->x86.R_CS = destval2;
			break;
		}
	} else {
		destval = *decode_rl_word_register(emu);
	}

	switch (emu->cur_rh) {
	case 2: /* call word ptr */
		push_word(emu, emu->x86.R_IP);
		emu->x86.R_IP = destval;
		break;
	case 4: /* jmp */
		emu->x86.R_IP = destval;
		break;
	}
}
/***************************************************************************
 * Single byte operation code table:
 **************************************************************************/
static void
X86EMU_exec_one_byte(struct X86EMU * emu)
{
	uint8_t op1;

	op1 = fetch_byte_imm(emu);

	switch (op1) {
	case 0x00:
		common_binop_byte_rm_r(emu, add_byte);
		break;
	case 0x01:
		common_binop_word_long_rm_r(emu, add_word, add_long);
		break;
	case 0x02:
		common_binop_byte_r_rm(emu, add_byte);
		break;
	case 0x03:
		common_binop_word_long_r_rm(emu, add_word, add_long);
		break;
	case 0x04:
		common_binop_byte_imm(emu, add_byte);
		break;
	case 0x05:
		common_binop_word_long_imm(emu, add_word, add_long);
		break;
	case 0x06:
		push_word(emu, emu->x86.R_ES);
		break;
	case 0x07:
		emu->x86.R_ES = pop_word(emu);
		break;

	case 0x08:
		common_binop_byte_rm_r(emu, or_byte);
		break;
	case 0x09:
		common_binop_word_long_rm_r(emu, or_word, or_long);
		break;
	case 0x0a:
		common_binop_byte_r_rm(emu, or_byte);
		break;
	case 0x0b:
		common_binop_word_long_r_rm(emu, or_word, or_long);
		break;
	case 0x0c:
		common_binop_byte_imm(emu, or_byte);
		break;
	case 0x0d:
		common_binop_word_long_imm(emu, or_word, or_long);
		break;
	case 0x0e:
		push_word(emu, emu->x86.R_CS);
		break;
	case 0x0f:
		X86EMU_exec_two_byte(emu);
		break;

	case 0x10:
		common_binop_byte_rm_r(emu, adc_byte);
		break;
	case 0x11:
		common_binop_word_long_rm_r(emu, adc_word, adc_long);
		break;
	case 0x12:
		common_binop_byte_r_rm(emu, adc_byte);
		break;
	case 0x13:
		common_binop_word_long_r_rm(emu, adc_word, adc_long);
		break;
	case 0x14:
		common_binop_byte_imm(emu, adc_byte);
		break;
	case 0x15:
		common_binop_word_long_imm(emu, adc_word, adc_long);
		break;
	case 0x16:
		push_word(emu, emu->x86.R_SS);
		break;
	case 0x17:
		emu->x86.R_SS = pop_word(emu);
		break;

	case 0x18:
		common_binop_byte_rm_r(emu, sbb_byte);
		break;
	case 0x19:
		common_binop_word_long_rm_r(emu, sbb_word, sbb_long);
		break;
	case 0x1a:
		common_binop_byte_r_rm(emu, sbb_byte);
		break;
	case 0x1b:
		common_binop_word_long_r_rm(emu, sbb_word, sbb_long);
		break;
	case 0x1c:
		common_binop_byte_imm(emu, sbb_byte);
		break;
	case 0x1d:
		common_binop_word_long_imm(emu, sbb_word, sbb_long);
		break;
	case 0x1e:
		push_word(emu, emu->x86.R_DS);
		break;
	case 0x1f:
		emu->x86.R_DS = pop_word(emu);
		break;

	case 0x20:
		common_binop_byte_rm_r(emu, and_byte);
		break;
	case 0x21:
		common_binop_word_long_rm_r(emu, and_word, and_long);
		break;
	case 0x22:
		common_binop_byte_r_rm(emu, and_byte);
		break;
	case 0x23:
		common_binop_word_long_r_rm(emu, and_word, and_long);
		break;
	case 0x24:
		common_binop_byte_imm(emu, and_byte);
		break;
	case 0x25:
		common_binop_word_long_imm(emu, and_word, and_long);
		break;
	case 0x26:
		emu->x86.mode |= SYSMODE_SEGOVR_ES;
		break;
	case 0x27:
		emu->x86.R_AL = daa_byte(emu, emu->x86.R_AL);
		break;

	case 0x28:
		common_binop_byte_rm_r(emu, sub_byte);
		break;
	case 0x29:
		common_binop_word_long_rm_r(emu, sub_word, sub_long);
		break;
	case 0x2a:
		common_binop_byte_r_rm(emu, sub_byte);
		break;
	case 0x2b:
		common_binop_word_long_r_rm(emu, sub_word, sub_long);
		break;
	case 0x2c:
		common_binop_byte_imm(emu, sub_byte);
		break;
	case 0x2d:
		common_binop_word_long_imm(emu, sub_word, sub_long);
		break;
	case 0x2e:
		emu->x86.mode |= SYSMODE_SEGOVR_CS;
		break;
	case 0x2f:
		emu->x86.R_AL = das_byte(emu, emu->x86.R_AL);
		break;

	case 0x30:
		common_binop_byte_rm_r(emu, xor_byte);
		break;
	case 0x31:
		common_binop_word_long_rm_r(emu, xor_word, xor_long);
		break;
	case 0x32:
		common_binop_byte_r_rm(emu, xor_byte);
		break;
	case 0x33:
		common_binop_word_long_r_rm(emu, xor_word, xor_long);
		break;
	case 0x34:
		common_binop_byte_imm(emu, xor_byte);
		break;
	case 0x35:
		common_binop_word_long_imm(emu, xor_word, xor_long);
		break;
	case 0x36:
		emu->x86.mode |= SYSMODE_SEGOVR_SS;
		break;
	case 0x37:
		emu->x86.R_AX = aaa_word(emu, emu->x86.R_AX);
		break;

	case 0x38:
		common_binop_ns_byte_rm_r(emu, cmp_byte_no_return);
		break;
	case 0x39:
		common_binop_ns_word_long_rm_r(emu, cmp_word_no_return,
		    cmp_long_no_return);
		break;
	case 0x3a:
		x86emuOp_cmp_byte_R_RM(emu);
		break;
	case 0x3b:
		x86emuOp_cmp_word_R_RM(emu);
		break;
	case 0x3c:
		x86emuOp_cmp_byte_AL_IMM(emu);
		break;
	case 0x3d:
		x86emuOp_cmp_word_AX_IMM(emu);
		break;
	case 0x3e:
		emu->x86.mode |= SYSMODE_SEGOVR_DS;
		break;
	case 0x3f:
		emu->x86.R_AX = aas_word(emu, emu->x86.R_AX);
		break;

	case 0x40:
		common_inc_word_long(emu, &emu->x86.register_a);
		break;
	case 0x41:
		common_inc_word_long(emu, &emu->x86.register_c);
		break;
	case 0x42:
		common_inc_word_long(emu, &emu->x86.register_d);
		break;
	case 0x43:
		common_inc_word_long(emu, &emu->x86.register_b);
		break;
	case 0x44:
		common_inc_word_long(emu, &emu->x86.register_sp);
		break;
	case 0x45:
		common_inc_word_long(emu, &emu->x86.register_bp);
		break;
	case 0x46:
		common_inc_word_long(emu, &emu->x86.register_si);
		break;
	case 0x47:
		common_inc_word_long(emu, &emu->x86.register_di);
		break;

	case 0x48:
		common_dec_word_long(emu, &emu->x86.register_a);
		break;
	case 0x49:
		common_dec_word_long(emu, &emu->x86.register_c);
		break;
	case 0x4a:
		common_dec_word_long(emu, &emu->x86.register_d);
		break;
	case 0x4b:
		common_dec_word_long(emu, &emu->x86.register_b);
		break;
	case 0x4c:
		common_dec_word_long(emu, &emu->x86.register_sp);
		break;
	case 0x4d:
		common_dec_word_long(emu, &emu->x86.register_bp);
		break;
	case 0x4e:
		common_dec_word_long(emu, &emu->x86.register_si);
		break;
	case 0x4f:
		common_dec_word_long(emu, &emu->x86.register_di);
		break;

	case 0x50:
		common_push_word_long(emu, &emu->x86.register_a);
		break;
	case 0x51:
		common_push_word_long(emu, &emu->x86.register_c);
		break;
	case 0x52:
		common_push_word_long(emu, &emu->x86.register_d);
		break;
	case 0x53:
		common_push_word_long(emu, &emu->x86.register_b);
		break;
	case 0x54:
		common_push_word_long(emu, &emu->x86.register_sp);
		break;
	case 0x55:
		common_push_word_long(emu, &emu->x86.register_bp);
		break;
	case 0x56:
		common_push_word_long(emu, &emu->x86.register_si);
		break;
	case 0x57:
		common_push_word_long(emu, &emu->x86.register_di);
		break;

	case 0x58:
		common_pop_word_long(emu, &emu->x86.register_a);
		break;
	case 0x59:
		common_pop_word_long(emu, &emu->x86.register_c);
		break;
	case 0x5a:
		common_pop_word_long(emu, &emu->x86.register_d);
		break;
	case 0x5b:
		common_pop_word_long(emu, &emu->x86.register_b);
		break;
	case 0x5c:
		common_pop_word_long(emu, &emu->x86.register_sp);
		break;
	case 0x5d:
		common_pop_word_long(emu, &emu->x86.register_bp);
		break;
	case 0x5e:
		common_pop_word_long(emu, &emu->x86.register_si);
		break;
	case 0x5f:
		common_pop_word_long(emu, &emu->x86.register_di);
		break;

	case 0x60:
		x86emuOp_push_all(emu);
		break;
	case 0x61:
		x86emuOp_pop_all(emu);
		break;
	/* 0x62 bound */
	/* 0x63 arpl */
	case 0x64:
		emu->x86.mode |= SYSMODE_SEGOVR_FS;
		break;
	case 0x65:
		emu->x86.mode |= SYSMODE_SEGOVR_GS;
		break;
	case 0x66:
		emu->x86.mode |= SYSMODE_PREFIX_DATA;
		break;
	case 0x67:
		emu->x86.mode |= SYSMODE_PREFIX_ADDR;
		break;

	case 0x68:
		x86emuOp_push_word_IMM(emu);
		break;
	case 0x69:
		common_imul_imm(emu, false);
		break;
	case 0x6a:
		x86emuOp_push_byte_IMM(emu);
		break;
	case 0x6b:
		common_imul_imm(emu, true);
		break;
	case 0x6c:
		ins(emu, 1);
		break;
	case 0x6d:
		x86emuOp_ins_word(emu);
		break;
	case 0x6e:
		outs(emu, 1);
		break;
	case 0x6f:
		x86emuOp_outs_word(emu);
		break;

	case 0x70:
		common_jmp_near(emu, ACCESS_FLAG(F_OF));
		break;
	case 0x71:
		common_jmp_near(emu, !ACCESS_FLAG(F_OF));
		break;
	case 0x72:
		common_jmp_near(emu, ACCESS_FLAG(F_CF));
		break;
	case 0x73:
		common_jmp_near(emu, !ACCESS_FLAG(F_CF));
		break;
	case 0x74:
		common_jmp_near(emu, ACCESS_FLAG(F_ZF));
		break;
	case 0x75:
		common_jmp_near(emu, !ACCESS_FLAG(F_ZF));
		break;
	case 0x76:
		common_jmp_near(emu, ACCESS_FLAG(F_CF) || ACCESS_FLAG(F_ZF));
		break;
	case 0x77:
		common_jmp_near(emu, !ACCESS_FLAG(F_CF) && !ACCESS_FLAG(F_ZF));
		break;

	case 0x78:
		common_jmp_near(emu, ACCESS_FLAG(F_SF));
		break;
	case 0x79:
		common_jmp_near(emu, !ACCESS_FLAG(F_SF));
		break;
	case 0x7a:
		common_jmp_near(emu, ACCESS_FLAG(F_PF));
		break;
	case 0x7b:
		common_jmp_near(emu, !ACCESS_FLAG(F_PF));
		break;
	case 0x7c:
		x86emuOp_jump_near_L(emu);
		break;
	case 0x7d:
		x86emuOp_jump_near_NL(emu);
		break;
	case 0x7e:
		x86emuOp_jump_near_LE(emu);
		break;
	case 0x7f:
		x86emuOp_jump_near_NLE(emu);
		break;

	case 0x80:
		x86emuOp_opc80_byte_RM_IMM(emu);
		break;
	case 0x81:
		x86emuOp_opc81_word_RM_IMM(emu);
		break;
	case 0x82:
		x86emuOp_opc82_byte_RM_IMM(emu);
		break;
	case 0x83:
		x86emuOp_opc83_word_RM_IMM(emu);
		break;
	case 0x84:
		common_binop_ns_byte_rm_r(emu, test_byte);
		break;
	case 0x85:
		common_binop_ns_word_long_rm_r(emu, test_word, test_long);
		break;
	case 0x86:
		x86emuOp_xchg_byte_RM_R(emu);
		break;
	case 0x87:
		x86emuOp_xchg_word_RM_R(emu);
		break;

	case 0x88:
		x86emuOp_mov_byte_RM_R(emu);
		break;
	case 0x89:
		x86emuOp_mov_word_RM_R(emu);
		break;
	case 0x8a:
		x86emuOp_mov_byte_R_RM(emu);
		break;
	case 0x8b:
		x86emuOp_mov_word_R_RM(emu);
		break;
	case 0x8c:
		x86emuOp_mov_word_RM_SR(emu);
		break;
	case 0x8d:
		x86emuOp_lea_word_R_M(emu);
		break;
	case 0x8e:
		x86emuOp_mov_word_SR_RM(emu);
		break;
	case 0x8f:
		x86emuOp_pop_RM(emu);
		break;

	case 0x90:
		/* nop */
		break;
	case 0x91:
		x86emuOp_xchg_word_AX_CX(emu);
		break;
	case 0x92:
		x86emuOp_xchg_word_AX_DX(emu);
		break;
	case 0x93:
		x86emuOp_xchg_word_AX_BX(emu);
		break;
	case 0x94:
		x86emuOp_xchg_word_AX_SP(emu);
		break;
	case 0x95:
		x86emuOp_xchg_word_AX_BP(emu);
		break;
	case 0x96:
		x86emuOp_xchg_word_AX_SI(emu);
		break;
	case 0x97:
		x86emuOp_xchg_word_AX_DI(emu);
		break;

	case 0x98:
		x86emuOp_cbw(emu);
		break;
	case 0x99:
		x86emuOp_cwd(emu);
		break;
	case 0x9a:
		x86emuOp_call_far_IMM(emu);
		break;
	case 0x9b:
		/* wait */
		break;
	case 0x9c:
		x86emuOp_pushf_word(emu);
		break;
	case 0x9d:
		x86emuOp_popf_word(emu);
		break;
	case 0x9e:
		x86emuOp_sahf(emu);
		break;
	case 0x9f:
		x86emuOp_lahf(emu);
		break;

	case 0xa0:
		x86emuOp_mov_AL_M_IMM(emu);
		break;
	case 0xa1:
		x86emuOp_mov_AX_M_IMM(emu);
		break;
	case 0xa2:
		x86emuOp_mov_M_AL_IMM(emu);
		break;
	case 0xa3:
		x86emuOp_mov_M_AX_IMM(emu);
		break;
	case 0xa4:
		x86emuOp_movs_byte(emu);
		break;
	case 0xa5:
		x86emuOp_movs_word(emu);
		break;
	case 0xa6:
		x86emuOp_cmps_byte(emu);
		break;
	case 0xa7:
		x86emuOp_cmps_word(emu);
		break;

	case 0xa8:
		test_byte(emu, emu->x86.R_AL, fetch_byte_imm(emu));
		break;
	case 0xa9:
		x86emuOp_test_AX_IMM(emu);
		break;
	case 0xaa:
		x86emuOp_stos_byte(emu);
		break;
	case 0xab:
		x86emuOp_stos_word(emu);
		break;
	case 0xac:
		x86emuOp_lods_byte(emu);
		break;
	case 0xad:
		x86emuOp_lods_word(emu);
		break;
	case 0xae:
		x86emuOp_scas_byte(emu);
		break;
	case 0xaf:
		x86emuOp_scas_word(emu);
		break;

	case 0xb0:
		emu->x86.R_AL = fetch_byte_imm(emu);
		break;
	case 0xb1:
		emu->x86.R_CL = fetch_byte_imm(emu);
		break;
	case 0xb2:
		emu->x86.R_DL = fetch_byte_imm(emu);
		break;
	case 0xb3:
		emu->x86.R_BL = fetch_byte_imm(emu);
		break;
	case 0xb4:
		emu->x86.R_AH = fetch_byte_imm(emu);
		break;
	case 0xb5:
		emu->x86.R_CH = fetch_byte_imm(emu);
		break;
	case 0xb6:
		emu->x86.R_DH = fetch_byte_imm(emu);
		break;
	case 0xb7:
		emu->x86.R_BH = fetch_byte_imm(emu);
		break;

	case 0xb8:
		x86emuOp_mov_word_AX_IMM(emu);
		break;
	case 0xb9:
		x86emuOp_mov_word_CX_IMM(emu);
		break;
	case 0xba:
		x86emuOp_mov_word_DX_IMM(emu);
		break;
	case 0xbb:
		x86emuOp_mov_word_BX_IMM(emu);
		break;
	case 0xbc:
		x86emuOp_mov_word_SP_IMM(emu);
		break;
	case 0xbd:
		x86emuOp_mov_word_BP_IMM(emu);
		break;
	case 0xbe:
		x86emuOp_mov_word_SI_IMM(emu);
		break;
	case 0xbf:
		x86emuOp_mov_word_DI_IMM(emu);
		break;

	case 0xc0:
		x86emuOp_opcC0_byte_RM_MEM(emu);
		break;
	case 0xc1:
		x86emuOp_opcC1_word_RM_MEM(emu);
		break;
	case 0xc2:
		x86emuOp_ret_near_IMM(emu);
		break;
	case 0xc3:
		emu->x86.R_IP = pop_word(emu);
		break;
	case 0xc4:
		common_load_far_pointer(emu, &emu->x86.R_ES);
		break;
	case 0xc5:
		common_load_far_pointer(emu, &emu->x86.R_DS);
		break;
	case 0xc6:
		x86emuOp_mov_byte_RM_IMM(emu);
		break;
	case 0xc7:
		x86emuOp_mov_word_RM_IMM(emu);
		break;
	case 0xc8:
		x86emuOp_enter(emu);
		break;
	case 0xc9:
		x86emuOp_leave(emu);
		break;
	case 0xca:
		x86emuOp_ret_far_IMM(emu);
		break;
	case 0xcb:
		x86emuOp_ret_far(emu);
		break;
	case 0xcc:
		x86emuOp_int3(emu);
		break;
	case 0xcd:
		x86emuOp_int_IMM(emu);
		break;
	case 0xce:
		x86emuOp_into(emu);
		break;
	case 0xcf:
		x86emuOp_iret(emu);
		break;

	case 0xd0:
		x86emuOp_opcD0_byte_RM_1(emu);
		break;
	case 0xd1:
		x86emuOp_opcD1_word_RM_1(emu);
		break;
	case 0xd2:
		x86emuOp_opcD2_byte_RM_CL(emu);
		break;
	case 0xd3:
		x86emuOp_opcD3_word_RM_CL(emu);
		break;
	case 0xd4:
		x86emuOp_aam(emu);
		break;
	case 0xd5:
		x86emuOp_aad(emu);
		break;
	/* 0xd6 Undocumented SETALC instruction */
	case 0xd7:
		x86emuOp_xlat(emu);
		break;
	case 0xd8:
		x86emuOp_esc_coprocess_d8(emu);
		break;
	case 0xd9:
		x86emuOp_esc_coprocess_d9(emu);
		break;
	case 0xda:
		x86emuOp_esc_coprocess_da(emu);
		break;
	case 0xdb:
		x86emuOp_esc_coprocess_db(emu);
		break;
	case 0xdc:
		x86emuOp_esc_coprocess_dc(emu);
		break;
	case 0xdd:
		x86emuOp_esc_coprocess_dd(emu);
		break;
	case 0xde:
		x86emuOp_esc_coprocess_de(emu);
		break;
	case 0xdf:
		x86emuOp_esc_coprocess_df(emu);
		break;

	case 0xe0:
		x86emuOp_loopne(emu);
		break;
	case 0xe1:
		x86emuOp_loope(emu);
		break;
	case 0xe2:
		x86emuOp_loop(emu);
		break;
	case 0xe3:
		x86emuOp_jcxz(emu);
		break;
	case 0xe4:
		x86emuOp_in_byte_AL_IMM(emu);
		break;
	case 0xe5:
		x86emuOp_in_word_AX_IMM(emu);
		break;
	case 0xe6:
		x86emuOp_out_byte_IMM_AL(emu);
		break;
	case 0xe7:
		x86emuOp_out_word_IMM_AX(emu);
		break;

	case 0xe8:
		x86emuOp_call_near_IMM(emu);
		break;
	case 0xe9:
		x86emuOp_jump_near_IMM(emu);
		break;
	case 0xea:
		x86emuOp_jump_far_IMM(emu);
		break;
	case 0xeb:
		x86emuOp_jump_byte_IMM(emu);
		break;
	case 0xec:
		x86emuOp_in_byte_AL_DX(emu);
		break;
	case 0xed:
		x86emuOp_in_word_AX_DX(emu);
		break;
	case 0xee:
		x86emuOp_out_byte_DX_AL(emu);
		break;
	case 0xef:
		x86emuOp_out_word_DX_AX(emu);
		break;

	case 0xf0:
		x86emuOp_lock(emu);
		break;
	case 0xf2:
		emu->x86.mode |= SYSMODE_PREFIX_REPNE;
		break;
	case 0xf3:
		emu->x86.mode |= SYSMODE_PREFIX_REPE;
		break;
	case 0xf4:
		X86EMU_halt_sys(emu);
		break;
	case 0xf5:
		x86emuOp_cmc(emu);
		break;
	case 0xf6:
		x86emuOp_opcF6_byte_RM(emu);
		break;
	case 0xf7:
		x86emuOp_opcF7_word_RM(emu);
		break;

	case 0xf8:
		CLEAR_FLAG(F_CF);
		break;
	case 0xf9:
		SET_FLAG(F_CF);
		break;
	case 0xfa:
		CLEAR_FLAG(F_IF);
		break;
	case 0xfb:
		SET_FLAG(F_IF);
		break;
	case 0xfc:
		CLEAR_FLAG(F_DF);
		break;
	case 0xfd:
		SET_FLAG(F_DF);
		break;
	case 0xfe:
		x86emuOp_opcFE_byte_RM(emu);
		break;
	case 0xff:
		x86emuOp_opcFF_word_RM(emu);
		break;
	default:
		X86EMU_halt_sys(emu);
		break;
	}
	if (op1 != 0x26 && op1 != 0x2e && op1 != 0x36 && op1 != 0x3e &&
	    (op1 | 3) != 0x67)
		emu->x86.mode &= ~SYSMODE_CLRMASK;
}

static void
common_jmp_long(struct X86EMU *emu, bool cond)
{
	int16_t target;

	target = (int16_t) fetch_word_imm(emu);
	target += (int16_t) emu->x86.R_IP;
	if (cond)
		emu->x86.R_IP = (uint16_t) target;
}

static void
common_set_byte(struct X86EMU *emu, bool cond)
{
	uint32_t destoffset;
	uint8_t *destreg, destval;

	fetch_decode_modrm(emu);
	destval = cond ? 0x01 : 0x00;
	if (emu->cur_mod != 3) {
		destoffset = decode_rl_address(emu);
		store_data_byte(emu, destoffset, destval);
	} else {
		destreg = decode_rl_byte_register(emu);
		*destreg = destval;
	}
}

static void
common_bitstring32(struct X86EMU *emu, int op)
{
	int bit;
	uint32_t srcval, *shiftreg, mask;

	fetch_decode_modrm(emu);
	shiftreg = decode_rh_long_register(emu);
	srcval = decode_and_fetch_long_disp(emu, (int16_t) *shiftreg >> 5);
	bit = *shiftreg & 0x1F;
	mask =  0x1 << bit;
	CONDITIONAL_SET_FLAG(srcval & mask, F_CF);

	switch (op) {
	case 0:
		break;
	case 1:
		write_back_long(emu, srcval | mask);
		break;
	case 2:
		write_back_long(emu, srcval & ~mask);
		break;
	case 3:
		write_back_long(emu, srcval ^ mask);
		break;
	}
}

static void
common_bitstring16(struct X86EMU *emu, int op)
{
	int bit;
	uint16_t srcval, *shiftreg, mask;

	fetch_decode_modrm(emu);
	shiftreg = decode_rh_word_register(emu);
	srcval = decode_and_fetch_word_disp(emu, (int16_t) *shiftreg >> 4);
	bit = *shiftreg & 0xF;
	mask =  0x1 << bit;
	CONDITIONAL_SET_FLAG(srcval & mask, F_CF);

	switch (op) {
	case 0:
		break;
	case 1:
		write_back_word(emu, srcval | mask);
		break;
	case 2:
		write_back_word(emu, srcval & ~mask);
		break;
	case 3:
		write_back_word(emu, srcval ^ mask);
		break;
	}
}

static void
common_bitstring(struct X86EMU *emu, int op)
{
	if (emu->x86.mode & SYSMODE_PREFIX_DATA)
		common_bitstring32(emu, op);
	else
		common_bitstring16(emu, op);
}

static void
common_bitsearch32(struct X86EMU *emu, int diff)
{
	uint32_t srcval, *dstreg;

	fetch_decode_modrm(emu);
	dstreg = decode_rh_long_register(emu);
	srcval = decode_and_fetch_long(emu);
	CONDITIONAL_SET_FLAG(srcval == 0, F_ZF);
	for (*dstreg = 0; *dstreg < 32; *dstreg += diff) {
		if ((srcval >> *dstreg) & 1)
			break;
	}
}

static void
common_bitsearch16(struct X86EMU *emu, int diff)
{
	uint16_t srcval, *dstreg;

	fetch_decode_modrm(emu);
	dstreg = decode_rh_word_register(emu);
	srcval = decode_and_fetch_word(emu);
	CONDITIONAL_SET_FLAG(srcval == 0, F_ZF);
	for (*dstreg = 0; *dstreg < 16; *dstreg += diff) {
		if ((srcval >> *dstreg) & 1)
			break;
	}
}

static void
common_bitsearch(struct X86EMU *emu, int diff)
{
	if (emu->x86.mode & SYSMODE_PREFIX_DATA)
		common_bitsearch32(emu, diff);
	else
		common_bitsearch16(emu, diff);
}

static void
common_shift32(struct X86EMU *emu, bool shift_left, bool use_cl)
{
	uint8_t shift;
	uint32_t destval, *shiftreg;

	fetch_decode_modrm(emu);
	shiftreg = decode_rh_long_register(emu);
	if (use_cl) {
		destval = decode_and_fetch_long(emu);
		shift = emu->x86.R_CL;
	} else {
		destval = decode_and_fetch_long_imm8(emu, &shift);
	}
	if (shift_left)
		destval = shld_long(emu, destval, *shiftreg, shift);
	else
		destval = shrd_long(emu, destval, *shiftreg, shift);
	write_back_long(emu, destval);
}

static void
common_shift16(struct X86EMU *emu, bool shift_left, bool use_cl)
{
	uint8_t shift;
	uint16_t destval, *shiftreg;

	fetch_decode_modrm(emu);
	shiftreg = decode_rh_word_register(emu);
	if (use_cl) {
		destval = decode_and_fetch_word(emu);
		shift = emu->x86.R_CL;
	} else {
		destval = decode_and_fetch_word_imm8(emu, &shift);
	}
	if (shift_left)
		destval = shld_word(emu, destval, *shiftreg, shift);
	else
		destval = shrd_word(emu, destval, *shiftreg, shift);
	write_back_word(emu, destval);
}

static void
common_shift(struct X86EMU *emu, bool shift_left, bool use_cl)
{
	if (emu->x86.mode & SYSMODE_PREFIX_DATA)
		common_shift32(emu, shift_left, use_cl);
	else
		common_shift16(emu, shift_left, use_cl);
}

/*----------------------------- Implementation ----------------------------*/
#define xorl(a,b)   ((a) && !(b)) || (!(a) && (b))

/****************************************************************************
REMARKS:
Handles opcode 0x0f,0x31
****************************************************************************/
static void
x86emuOp2_rdtsc(struct X86EMU *emu)
{
	emu->x86.R_EAX = emu->cur_cycles & 0xffffffff;
	emu->x86.R_EDX = emu->cur_cycles >> 32;
}
/****************************************************************************
REMARKS:
Handles opcode 0x0f,0xa0
****************************************************************************/
static void
x86emuOp2_push_FS(struct X86EMU *emu)
{
	push_word(emu, emu->x86.R_FS);
}
/****************************************************************************
REMARKS:
Handles opcode 0x0f,0xa1
****************************************************************************/
static void
x86emuOp2_pop_FS(struct X86EMU *emu)
{
	emu->x86.R_FS = pop_word(emu);
}
/****************************************************************************
REMARKS:
Handles opcode 0x0f,0xa1
****************************************************************************/
#if defined(__i386__) || defined(__amd64__)
static void
hw_cpuid(uint32_t *a, uint32_t *b, uint32_t *c, uint32_t *d)
{
	__asm__ __volatile__("cpuid"
			     : "=a" (*a), "=b" (*b),
			       "=c" (*c), "=d" (*d)
			     : "a" (*a), "c" (*c)
			     : "cc");
}
#endif
static void
x86emuOp2_cpuid(struct X86EMU *emu)
{
#if defined(__i386__) || defined(__amd64__)
	hw_cpuid(&emu->x86.R_EAX, &emu->x86.R_EBX, &emu->x86.R_ECX,
	    &emu->x86.R_EDX);
#endif
	switch (emu->x86.R_EAX) {
	case 0:
		emu->x86.R_EAX = 1;
#if !defined(__i386__) && !defined(__amd64__)
		/* "GenuineIntel" */
		emu->x86.R_EBX = 0x756e6547;
		emu->x86.R_EDX = 0x49656e69;
		emu->x86.R_ECX = 0x6c65746e;
#endif
		break;
	case 1:
#if !defined(__i386__) && !defined(__amd64__)
		emu->x86.R_EAX = 0x00000480;
		emu->x86.R_EBX = emu->x86.R_ECX = 0;
		emu->x86.R_EDX = 0x00000002;
#else
		emu->x86.R_EDX &= 0x00000012;
#endif
		break;
	default:
		emu->x86.R_EAX = emu->x86.R_EBX = emu->x86.R_ECX =
		    emu->x86.R_EDX = 0;
		break;
	}
}
/****************************************************************************
REMARKS:
Handles opcode 0x0f,0xa3
****************************************************************************/
static void
x86emuOp2_bt_R(struct X86EMU *emu)
{
	common_bitstring(emu, 0);
}
/****************************************************************************
REMARKS:
Handles opcode 0x0f,0xa4
****************************************************************************/
static void
x86emuOp2_shld_IMM(struct X86EMU *emu)
{
	common_shift(emu, true, false);
}
/****************************************************************************
REMARKS:
Handles opcode 0x0f,0xa5
****************************************************************************/
static void
x86emuOp2_shld_CL(struct X86EMU *emu)
{
	common_shift(emu, true, true);
}
/****************************************************************************
REMARKS:
Handles opcode 0x0f,0xa8
****************************************************************************/
static void
x86emuOp2_push_GS(struct X86EMU *emu)
{
	push_word(emu, emu->x86.R_GS);
}
/****************************************************************************
REMARKS:
Handles opcode 0x0f,0xa9
****************************************************************************/
static void
x86emuOp2_pop_GS(struct X86EMU *emu)
{
	emu->x86.R_GS = pop_word(emu);
}
/****************************************************************************
REMARKS:
Handles opcode 0x0f,0xab
****************************************************************************/
static void
x86emuOp2_bts_R(struct X86EMU *emu)
{
	common_bitstring(emu, 1);
}
/****************************************************************************
REMARKS:
Handles opcode 0x0f,0xac
****************************************************************************/
static void
x86emuOp2_shrd_IMM(struct X86EMU *emu)
{
	common_shift(emu, false, false);
}
/****************************************************************************
REMARKS:
Handles opcode 0x0f,0xad
****************************************************************************/
static void
x86emuOp2_shrd_CL(struct X86EMU *emu)
{
	common_shift(emu, false, true);
}
/****************************************************************************
REMARKS:
Handles opcode 0x0f,0xaf
****************************************************************************/
static void
x86emuOp2_32_imul_R_RM(struct X86EMU *emu)
{
	uint32_t *destreg, srcval;
	uint64_t res;

	fetch_decode_modrm(emu);
	destreg = decode_rh_long_register(emu);
	srcval = decode_and_fetch_long(emu);
	res = (int32_t) *destreg * (int32_t)srcval;
	if (res > 0xffffffff) {
		SET_FLAG(F_CF);
		SET_FLAG(F_OF);
	} else {
		CLEAR_FLAG(F_CF);
		CLEAR_FLAG(F_OF);
	}
	*destreg = (uint32_t) res;
}

static void
x86emuOp2_16_imul_R_RM(struct X86EMU *emu)
{
	uint16_t *destreg, srcval;
	uint32_t res;

	fetch_decode_modrm(emu);
	destreg = decode_rh_word_register(emu);
	srcval = decode_and_fetch_word(emu);
	res = (int16_t) * destreg * (int16_t)srcval;
	if (res > 0xFFFF) {
		SET_FLAG(F_CF);
		SET_FLAG(F_OF);
	} else {
		CLEAR_FLAG(F_CF);
		CLEAR_FLAG(F_OF);
	}
	*destreg = (uint16_t) res;
}

static void
x86emuOp2_imul_R_RM(struct X86EMU *emu)
{
	if (emu->x86.mode & SYSMODE_PREFIX_DATA)
		x86emuOp2_32_imul_R_RM(emu);
	else
		x86emuOp2_16_imul_R_RM(emu);
}
/****************************************************************************
REMARKS:
Handles opcode 0x0f,0xb2
****************************************************************************/
static void
x86emuOp2_lss_R_IMM(struct X86EMU *emu)
{
	common_load_far_pointer(emu, &emu->x86.R_SS);
}
/****************************************************************************
REMARKS:
Handles opcode 0x0f,0xb3
****************************************************************************/
static void
x86emuOp2_btr_R(struct X86EMU *emu)
{
	common_bitstring(emu, 2);
}
/****************************************************************************
REMARKS:
Handles opcode 0x0f,0xb4
****************************************************************************/
static void
x86emuOp2_lfs_R_IMM(struct X86EMU *emu)
{
	common_load_far_pointer(emu, &emu->x86.R_FS);
}
/****************************************************************************
REMARKS:
Handles opcode 0x0f,0xb5
****************************************************************************/
static void
x86emuOp2_lgs_R_IMM(struct X86EMU *emu)
{
	common_load_far_pointer(emu, &emu->x86.R_GS);
}
/****************************************************************************
REMARKS:
Handles opcode 0x0f,0xb6
****************************************************************************/
static void
x86emuOp2_32_movzx_byte_R_RM(struct X86EMU *emu)
{
	uint32_t *destreg;

	fetch_decode_modrm(emu);
	destreg = decode_rh_long_register(emu);
	*destreg = decode_and_fetch_byte(emu);
}

static void
x86emuOp2_16_movzx_byte_R_RM(struct X86EMU *emu)
{
	uint16_t *destreg;

	fetch_decode_modrm(emu);
	destreg = decode_rh_word_register(emu);
	*destreg = decode_and_fetch_byte(emu);
}

static void
x86emuOp2_movzx_byte_R_RM(struct X86EMU *emu)
{
	if (emu->x86.mode & SYSMODE_PREFIX_DATA)
		x86emuOp2_32_movzx_byte_R_RM(emu);
	else
		x86emuOp2_16_movzx_byte_R_RM(emu);
}
/****************************************************************************
REMARKS:
Handles opcode 0x0f,0xb7
****************************************************************************/
static void
x86emuOp2_movzx_word_R_RM(struct X86EMU *emu)
{
	uint32_t *destreg;

	fetch_decode_modrm(emu);
	destreg = decode_rh_long_register(emu);
	*destreg = decode_and_fetch_word(emu);
}
/****************************************************************************
REMARKS:
Handles opcode 0x0f,0xba
****************************************************************************/
static void
x86emuOp2_32_btX_I(struct X86EMU *emu)
{
	int bit;
	uint32_t srcval, mask;
	uint8_t shift;

	fetch_decode_modrm(emu);
	if (emu->cur_rh < 4)
		X86EMU_halt_sys(emu);

	srcval = decode_and_fetch_long_imm8(emu, &shift);
	bit = shift & 0x1F;
	mask = (0x1 << bit);

	switch (emu->cur_rh) {
	case 5:
		write_back_long(emu, srcval | mask);
		break;
	case 6:
		write_back_long(emu, srcval & ~mask);
		break;
	case 7:
		write_back_long(emu, srcval ^ mask);
		break;
	}
	CONDITIONAL_SET_FLAG(srcval & mask, F_CF);
}

static void
x86emuOp2_16_btX_I(struct X86EMU *emu)
{
	int bit;

	uint16_t srcval, mask;
	uint8_t shift;

	fetch_decode_modrm(emu);
	if (emu->cur_rh < 4)
		X86EMU_halt_sys(emu);

	srcval = decode_and_fetch_word_imm8(emu, &shift);
	bit = shift & 0xF;
	mask = (0x1 << bit);
	switch (emu->cur_rh) {
	case 5:
		write_back_word(emu, srcval | mask);
		break;
	case 6:
		write_back_word(emu, srcval & ~mask);
		break;
	case 7:
		write_back_word(emu, srcval ^ mask);
		break;
	}
	CONDITIONAL_SET_FLAG(srcval & mask, F_CF);
}

static void
x86emuOp2_btX_I(struct X86EMU *emu)
{
	if (emu->x86.mode & SYSMODE_PREFIX_DATA)
		x86emuOp2_32_btX_I(emu);
	else
		x86emuOp2_16_btX_I(emu);
}
/****************************************************************************
REMARKS:
Handles opcode 0x0f,0xbb
****************************************************************************/
static void
x86emuOp2_btc_R(struct X86EMU *emu)
{
	common_bitstring(emu, 3);
}
/****************************************************************************
REMARKS:
Handles opcode 0x0f,0xbc
****************************************************************************/
static void
x86emuOp2_bsf(struct X86EMU *emu)
{
	common_bitsearch(emu, +1);
}
/****************************************************************************
REMARKS:
Handles opcode 0x0f,0xbd
****************************************************************************/
static void
x86emuOp2_bsr(struct X86EMU *emu)
{
	common_bitsearch(emu, -1);
}
/****************************************************************************
REMARKS:
Handles opcode 0x0f,0xbe
****************************************************************************/
static void
x86emuOp2_32_movsx_byte_R_RM(struct X86EMU *emu)
{
	uint32_t *destreg;

	fetch_decode_modrm(emu);
	destreg = decode_rh_long_register(emu);
	*destreg = (int32_t)(int8_t)decode_and_fetch_byte(emu);
}

static void
x86emuOp2_16_movsx_byte_R_RM(struct X86EMU *emu)
{
	uint16_t *destreg;

	fetch_decode_modrm(emu);
	destreg = decode_rh_word_register(emu);
	*destreg = (int16_t)(int8_t)decode_and_fetch_byte(emu);
}

static void
x86emuOp2_movsx_byte_R_RM(struct X86EMU *emu)
{
	if (emu->x86.mode & SYSMODE_PREFIX_DATA)
		x86emuOp2_32_movsx_byte_R_RM(emu);
	else
		x86emuOp2_16_movsx_byte_R_RM(emu);
}
/****************************************************************************
REMARKS:
Handles opcode 0x0f,0xbf
****************************************************************************/
static void
x86emuOp2_movsx_word_R_RM(struct X86EMU *emu)
{
	uint32_t *destreg;

	fetch_decode_modrm(emu);
	destreg = decode_rh_long_register(emu);
	*destreg = (int32_t)(int16_t)decode_and_fetch_word(emu);
}

static void
X86EMU_exec_two_byte(struct X86EMU * emu)
{
	uint8_t op2;

	op2 = fetch_byte_imm(emu);

	switch (op2) {
	/* 0x00 Group F (ring 0 PM)      */
	/* 0x01 Group G (ring 0 PM)      */
	/* 0x02 lar (ring 0 PM)          */
	/* 0x03 lsl (ring 0 PM)          */
	/* 0x05 loadall (undocumented)   */
	/* 0x06 clts (ring 0 PM)         */
	/* 0x07 loadall (undocumented)   */
	/* 0x08 invd (ring 0 PM)         */
	/* 0x09 wbinvd (ring 0 PM)       */

	/* 0x20 mov reg32(op2); break;creg (ring 0 PM) */
	/* 0x21 mov reg32(op2); break;dreg (ring 0 PM) */
	/* 0x22 mov creg(op2); break;reg32 (ring 0 PM) */
	/* 0x23 mov dreg(op2); break;reg32 (ring 0 PM) */
	/* 0x24 mov reg32(op2); break;treg (ring 0 PM) */
	/* 0x26 mov treg(op2); break;reg32 (ring 0 PM) */

	case 0x31:
		x86emuOp2_rdtsc(emu);
		break;

	case 0x80:
		common_jmp_long(emu, ACCESS_FLAG(F_OF));
		break;
	case 0x81:
		common_jmp_long(emu, !ACCESS_FLAG(F_OF));
		break;
	case 0x82:
		common_jmp_long(emu, ACCESS_FLAG(F_CF));
		break;
	case 0x83:
		common_jmp_long(emu, !ACCESS_FLAG(F_CF));
		break;
	case 0x84:
		common_jmp_long(emu, ACCESS_FLAG(F_ZF));
		break;
	case 0x85:
		common_jmp_long(emu, !ACCESS_FLAG(F_ZF));
		break;
	case 0x86:
		common_jmp_long(emu, ACCESS_FLAG(F_CF) || ACCESS_FLAG(F_ZF));
		break;
	case 0x87:
		common_jmp_long(emu, !(ACCESS_FLAG(F_CF) || ACCESS_FLAG(F_ZF)));
		break;
	case 0x88:
		common_jmp_long(emu, ACCESS_FLAG(F_SF));
		break;
	case 0x89:
		common_jmp_long(emu, !ACCESS_FLAG(F_SF));
		break;
	case 0x8a:
		common_jmp_long(emu, ACCESS_FLAG(F_PF));
		break;
	case 0x8b:
		common_jmp_long(emu, !ACCESS_FLAG(F_PF));
		break;
	case 0x8c:
		common_jmp_long(emu, xorl(ACCESS_FLAG(F_SF), ACCESS_FLAG(F_OF)));
		break;
	case 0x8d:
		common_jmp_long(emu, !(xorl(ACCESS_FLAG(F_SF), ACCESS_FLAG(F_OF))));
		break;
	case 0x8e:
		common_jmp_long(emu,
		    (xorl(ACCESS_FLAG(F_SF), ACCESS_FLAG(F_OF)) || ACCESS_FLAG(F_ZF)));
		break;
	case 0x8f:
		common_jmp_long(emu,
		    !(xorl(ACCESS_FLAG(F_SF), ACCESS_FLAG(F_OF)) || ACCESS_FLAG(F_ZF)));
		break;

	case 0x90:
		common_set_byte(emu, ACCESS_FLAG(F_OF));
		break;
	case 0x91:
		common_set_byte(emu, !ACCESS_FLAG(F_OF));
		break;
	case 0x92:
		common_set_byte(emu, ACCESS_FLAG(F_CF));
		break;
	case 0x93:
		common_set_byte(emu, !ACCESS_FLAG(F_CF));
		break;
	case 0x94:
		common_set_byte(emu, ACCESS_FLAG(F_ZF));
		break;
	case 0x95:
		common_set_byte(emu, !ACCESS_FLAG(F_ZF));
		break;
	case 0x96:
		common_set_byte(emu, ACCESS_FLAG(F_CF) || ACCESS_FLAG(F_ZF));
		break;
	case 0x97:
		common_set_byte(emu, !(ACCESS_FLAG(F_CF) || ACCESS_FLAG(F_ZF)));
		break;
	case 0x98:
		common_set_byte(emu, ACCESS_FLAG(F_SF));
		break;
	case 0x99:
		common_set_byte(emu, !ACCESS_FLAG(F_SF));
		break;
	case 0x9a:
		common_set_byte(emu, ACCESS_FLAG(F_PF));
		break;
	case 0x9b:
		common_set_byte(emu, !ACCESS_FLAG(F_PF));
		break;
	case 0x9c:
		common_set_byte(emu, xorl(ACCESS_FLAG(F_SF), ACCESS_FLAG(F_OF)));
		break;
	case 0x9d:
		common_set_byte(emu, xorl(ACCESS_FLAG(F_SF), ACCESS_FLAG(F_OF)));
		break;
	case 0x9e:
		common_set_byte(emu,
		    (xorl(ACCESS_FLAG(F_SF), ACCESS_FLAG(F_OF)) ||
		    ACCESS_FLAG(F_ZF)));
		break;
	case 0x9f:
		common_set_byte(emu,
		    !(xorl(ACCESS_FLAG(F_SF), ACCESS_FLAG(F_OF)) ||
		    ACCESS_FLAG(F_ZF)));
		break;

	case 0xa0:
		x86emuOp2_push_FS(emu);
		break;
	case 0xa1:
		x86emuOp2_pop_FS(emu);
		break;
	case 0xa2:
		x86emuOp2_cpuid(emu);
		break;
	case 0xa3:
		x86emuOp2_bt_R(emu);
		break;
	case 0xa4:
		x86emuOp2_shld_IMM(emu);
		break;
	case 0xa5:
		x86emuOp2_shld_CL(emu);
		break;
	case 0xa8:
		x86emuOp2_push_GS(emu);
		break;
	case 0xa9:
		x86emuOp2_pop_GS(emu);
		break;
	case 0xab:
		x86emuOp2_bts_R(emu);
		break;
	case 0xac:
		x86emuOp2_shrd_IMM(emu);
		break;
	case 0xad:
		x86emuOp2_shrd_CL(emu);
		break;
	case 0xaf:
		x86emuOp2_imul_R_RM(emu);
		break;

	/* 0xb0 TODO: cmpxchg */
	/* 0xb1 TODO: cmpxchg */
	case 0xb2:
		x86emuOp2_lss_R_IMM(emu);
		break;
	case 0xb3:
		x86emuOp2_btr_R(emu);
		break;
	case 0xb4:
		x86emuOp2_lfs_R_IMM(emu);
		break;
	case 0xb5:
		x86emuOp2_lgs_R_IMM(emu);
		break;
	case 0xb6:
		x86emuOp2_movzx_byte_R_RM(emu);
		break;
	case 0xb7:
		x86emuOp2_movzx_word_R_RM(emu);
		break;
	case 0xba:
		x86emuOp2_btX_I(emu);
		break;
	case 0xbb:
		x86emuOp2_btc_R(emu);
		break;
	case 0xbc:
		x86emuOp2_bsf(emu);
		break;
	case 0xbd:
		x86emuOp2_bsr(emu);
		break;
	case 0xbe:
		x86emuOp2_movsx_byte_R_RM(emu);
		break;
	case 0xbf:
		x86emuOp2_movsx_word_R_RM(emu);
		break;

	/* 0xc0 TODO: xadd */
	/* 0xc1 TODO: xadd */
	/* 0xc8 TODO: bswap */
	/* 0xc9 TODO: bswap */
	/* 0xca TODO: bswap */
	/* 0xcb TODO: bswap */
	/* 0xcc TODO: bswap */
	/* 0xcd TODO: bswap */
	/* 0xce TODO: bswap */
	/* 0xcf TODO: bswap */

	default:
		X86EMU_halt_sys(emu);
		break;
	}
}

/*
* Carry Chain Calculation
*
* This represents a somewhat expensive calculation which is
* apparently required to emulate the setting of the OF and AF flag.
* The latter is not so important, but the former is.  The overflow
* flag is the XOR of the top two bits of the carry chain for an
* addition (similar for subtraction).  Since we do not want to
* simulate the addition in a bitwise manner, we try to calculate the
* carry chain given the two operands and the result.
*
* So, given the following table, which represents the addition of two
* bits, we can derive a formula for the carry chain.
*
* a   b   cin   r     cout
* 0   0   0     0     0
* 0   0   1     1     0
* 0   1   0     1     0
* 0   1   1     0     1
* 1   0   0     1     0
* 1   0   1     0     1
* 1   1   0     0     1
* 1   1   1     1     1
*
* Construction of table for cout:
*
* ab
* r  \  00   01   11  10
* |------------------
* 0  |   0    1    1   1
* 1  |   0    0    1   0
*
* By inspection, one gets:  cc = ab +  r'(a + b)
*
* That represents alot of operations, but NO CHOICE....
*
* Borrow Chain Calculation.
*
* The following table represents the subtraction of two bits, from
* which we can derive a formula for the borrow chain.
*
* a   b   bin   r     bout
* 0   0   0     0     0
* 0   0   1     1     1
* 0   1   0     1     1
* 0   1   1     0     1
* 1   0   0     1     0
* 1   0   1     0     0
* 1   1   0     0     0
* 1   1   1     1     1
*
* Construction of table for cout:
*
* ab
* r  \  00   01   11  10
* |------------------
* 0  |   0    1    0   0
* 1  |   1    1    1   0
*
* By inspection, one gets:  bc = a'b +  r(a' + b)
*
****************************************************************************/

/*------------------------- Global Variables ------------------------------*/

static uint32_t x86emu_parity_tab[8] =
{
	0x96696996,
	0x69969669,
	0x69969669,
	0x96696996,
	0x69969669,
	0x96696996,
	0x96696996,
	0x69969669,
};
#define PARITY(x)   (((x86emu_parity_tab[(x) / 32] >> ((x) % 32)) & 1) == 0)
#define XOR2(x) 	(((x) ^ ((x)>>1)) & 0x1)

/****************************************************************************
REMARKS:
Implements the AAA instruction and side effects.
****************************************************************************/
static uint16_t
aaa_word(struct X86EMU *emu, uint16_t d)
{
	uint16_t res;
	if ((d & 0xf) > 0x9 || ACCESS_FLAG(F_AF)) {
		d += 0x6;
		d += 0x100;
		SET_FLAG(F_AF);
		SET_FLAG(F_CF);
	} else {
		CLEAR_FLAG(F_CF);
		CLEAR_FLAG(F_AF);
	}
	res = (uint16_t) (d & 0xFF0F);
	CLEAR_FLAG(F_SF);
	CONDITIONAL_SET_FLAG(res == 0, F_ZF);
	CONDITIONAL_SET_FLAG(PARITY(res & 0xff), F_PF);
	return res;
}
/****************************************************************************
REMARKS:
Implements the AAA instruction and side effects.
****************************************************************************/
static uint16_t
aas_word(struct X86EMU *emu, uint16_t d)
{
	uint16_t res;
	if ((d & 0xf) > 0x9 || ACCESS_FLAG(F_AF)) {
		d -= 0x6;
		d -= 0x100;
		SET_FLAG(F_AF);
		SET_FLAG(F_CF);
	} else {
		CLEAR_FLAG(F_CF);
		CLEAR_FLAG(F_AF);
	}
	res = (uint16_t) (d & 0xFF0F);
	CLEAR_FLAG(F_SF);
	CONDITIONAL_SET_FLAG(res == 0, F_ZF);
	CONDITIONAL_SET_FLAG(PARITY(res & 0xff), F_PF);
	return res;
}
/****************************************************************************
REMARKS:
Implements the AAD instruction and side effects.
****************************************************************************/
static uint16_t
aad_word(struct X86EMU *emu, uint16_t d)
{
	uint16_t l;
	uint8_t hb, lb;

	hb = (uint8_t) ((d >> 8) & 0xff);
	lb = (uint8_t) ((d & 0xff));
	l = (uint16_t) ((lb + 10 * hb) & 0xFF);

	CLEAR_FLAG(F_CF);
	CLEAR_FLAG(F_AF);
	CLEAR_FLAG(F_OF);
	CONDITIONAL_SET_FLAG(l & 0x80, F_SF);
	CONDITIONAL_SET_FLAG(l == 0, F_ZF);
	CONDITIONAL_SET_FLAG(PARITY(l & 0xff), F_PF);
	return l;
}
/****************************************************************************
REMARKS:
Implements the AAM instruction and side effects.
****************************************************************************/
static uint16_t
aam_word(struct X86EMU *emu, uint8_t d)
{
	uint16_t h, l;

	h = (uint16_t) (d / 10);
	l = (uint16_t) (d % 10);
	l |= (uint16_t) (h << 8);

	CLEAR_FLAG(F_CF);
	CLEAR_FLAG(F_AF);
	CLEAR_FLAG(F_OF);
	CONDITIONAL_SET_FLAG(l & 0x80, F_SF);
	CONDITIONAL_SET_FLAG(l == 0, F_ZF);
	CONDITIONAL_SET_FLAG(PARITY(l & 0xff), F_PF);
	return l;
}
/****************************************************************************
REMARKS:
Implements the ADC instruction and side effects.
****************************************************************************/
static uint8_t
adc_byte(struct X86EMU *emu, uint8_t d, uint8_t s)
{
	uint32_t res;	/* all operands in native machine order */
	uint32_t cc;

	if (ACCESS_FLAG(F_CF))
		res = 1 + d + s;
	else
		res = d + s;

	CONDITIONAL_SET_FLAG(res & 0x100, F_CF);
	CONDITIONAL_SET_FLAG((res & 0xff) == 0, F_ZF);
	CONDITIONAL_SET_FLAG(res & 0x80, F_SF);
	CONDITIONAL_SET_FLAG(PARITY(res & 0xff), F_PF);

	/* calculate the carry chain  SEE NOTE AT TOP. */
	cc = (s & d) | ((~res) & (s | d));
	CONDITIONAL_SET_FLAG(XOR2(cc >> 6), F_OF);
	CONDITIONAL_SET_FLAG(cc & 0x8, F_AF);
	return (uint8_t) res;
}
/****************************************************************************
REMARKS:
Implements the ADC instruction and side effects.
****************************************************************************/
static uint16_t
adc_word(struct X86EMU *emu, uint16_t d, uint16_t s)
{
	uint32_t res;	/* all operands in native machine order */
	uint32_t cc;

	if (ACCESS_FLAG(F_CF))
		res = 1 + d + s;
	else
		res = d + s;

	CONDITIONAL_SET_FLAG(res & 0x10000, F_CF);
	CONDITIONAL_SET_FLAG((res & 0xffff) == 0, F_ZF);
	CONDITIONAL_SET_FLAG(res & 0x8000, F_SF);
	CONDITIONAL_SET_FLAG(PARITY(res & 0xff), F_PF);

	/* calculate the carry chain  SEE NOTE AT TOP. */
	cc = (s & d) | ((~res) & (s | d));
	CONDITIONAL_SET_FLAG(XOR2(cc >> 14), F_OF);
	CONDITIONAL_SET_FLAG(cc & 0x8, F_AF);
	return (uint16_t) res;
}
/****************************************************************************
REMARKS:
Implements the ADC instruction and side effects.
****************************************************************************/
static uint32_t
adc_long(struct X86EMU *emu, uint32_t d, uint32_t s)
{
	uint32_t lo;	/* all operands in native machine order */
	uint32_t hi;
	uint32_t res;
	uint32_t cc;

	if (ACCESS_FLAG(F_CF)) {
		lo = 1 + (d & 0xFFFF) + (s & 0xFFFF);
		res = 1 + d + s;
	} else {
		lo = (d & 0xFFFF) + (s & 0xFFFF);
		res = d + s;
	}
	hi = (lo >> 16) + (d >> 16) + (s >> 16);

	CONDITIONAL_SET_FLAG(hi & 0x10000, F_CF);
	CONDITIONAL_SET_FLAG((res & 0xffffffff) == 0, F_ZF);
	CONDITIONAL_SET_FLAG(res & 0x80000000, F_SF);
	CONDITIONAL_SET_FLAG(PARITY(res & 0xff), F_PF);

	/* calculate the carry chain  SEE NOTE AT TOP. */
	cc = (s & d) | ((~res) & (s | d));
	CONDITIONAL_SET_FLAG(XOR2(cc >> 30), F_OF);
	CONDITIONAL_SET_FLAG(cc & 0x8, F_AF);
	return res;
}
/****************************************************************************
REMARKS:
Implements the ADD instruction and side effects.
****************************************************************************/
static uint8_t
add_byte(struct X86EMU *emu, uint8_t d, uint8_t s)
{
	uint32_t res;	/* all operands in native machine order */
	uint32_t cc;

	res = d + s;
	CONDITIONAL_SET_FLAG(res & 0x100, F_CF);
	CONDITIONAL_SET_FLAG((res & 0xff) == 0, F_ZF);
	CONDITIONAL_SET_FLAG(res & 0x80, F_SF);
	CONDITIONAL_SET_FLAG(PARITY(res & 0xff), F_PF);

	/* calculate the carry chain  SEE NOTE AT TOP. */
	cc = (s & d) | ((~res) & (s | d));
	CONDITIONAL_SET_FLAG(XOR2(cc >> 6), F_OF);
	CONDITIONAL_SET_FLAG(cc & 0x8, F_AF);
	return (uint8_t) res;
}
/****************************************************************************
REMARKS:
Implements the ADD instruction and side effects.
****************************************************************************/
static uint16_t
add_word(struct X86EMU *emu, uint16_t d, uint16_t s)
{
	uint32_t res;	/* all operands in native machine order */
	uint32_t cc;

	res = d + s;
	CONDITIONAL_SET_FLAG(res & 0x10000, F_CF);
	CONDITIONAL_SET_FLAG((res & 0xffff) == 0, F_ZF);
	CONDITIONAL_SET_FLAG(res & 0x8000, F_SF);
	CONDITIONAL_SET_FLAG(PARITY(res & 0xff), F_PF);

	/* calculate the carry chain  SEE NOTE AT TOP. */
	cc = (s & d) | ((~res) & (s | d));
	CONDITIONAL_SET_FLAG(XOR2(cc >> 14), F_OF);
	CONDITIONAL_SET_FLAG(cc & 0x8, F_AF);
	return (uint16_t) res;
}
/****************************************************************************
REMARKS:
Implements the ADD instruction and side effects.
****************************************************************************/
static uint32_t
add_long(struct X86EMU *emu, uint32_t d, uint32_t s)
{
	uint32_t lo;	/* all operands in native machine order */
	uint32_t hi;
	uint32_t res;
	uint32_t cc;

	lo = (d & 0xFFFF) + (s & 0xFFFF);
	res = d + s;
	hi = (lo >> 16) + (d >> 16) + (s >> 16);

	CONDITIONAL_SET_FLAG(hi & 0x10000, F_CF);
	CONDITIONAL_SET_FLAG((res & 0xffffffff) == 0, F_ZF);
	CONDITIONAL_SET_FLAG(res & 0x80000000, F_SF);
	CONDITIONAL_SET_FLAG(PARITY(res & 0xff), F_PF);

	/* calculate the carry chain  SEE NOTE AT TOP. */
	cc = (s & d) | ((~res) & (s | d));
	CONDITIONAL_SET_FLAG(XOR2(cc >> 30), F_OF);
	CONDITIONAL_SET_FLAG(cc & 0x8, F_AF);

	return res;
}
/****************************************************************************
REMARKS:
Implements the AND instruction and side effects.
****************************************************************************/
static uint8_t
and_byte(struct X86EMU *emu, uint8_t d, uint8_t s)
{
	uint8_t res;	/* all operands in native machine order */

	res = d & s;

	/* set the flags  */
	CLEAR_FLAG(F_OF);
	CLEAR_FLAG(F_CF);
	CLEAR_FLAG(F_AF);
	CONDITIONAL_SET_FLAG(res & 0x80, F_SF);
	CONDITIONAL_SET_FLAG(res == 0, F_ZF);
	CONDITIONAL_SET_FLAG(PARITY(res), F_PF);
	return res;
}
/****************************************************************************
REMARKS:
Implements the AND instruction and side effects.
****************************************************************************/
static uint16_t
and_word(struct X86EMU *emu, uint16_t d, uint16_t s)
{
	uint16_t res;	/* all operands in native machine order */

	res = d & s;

	/* set the flags  */
	CLEAR_FLAG(F_OF);
	CLEAR_FLAG(F_CF);
	CLEAR_FLAG(F_AF);
	CONDITIONAL_SET_FLAG(res & 0x8000, F_SF);
	CONDITIONAL_SET_FLAG(res == 0, F_ZF);
	CONDITIONAL_SET_FLAG(PARITY(res & 0xff), F_PF);
	return res;
}
/****************************************************************************
REMARKS:
Implements the AND instruction and side effects.
****************************************************************************/
static uint32_t
and_long(struct X86EMU *emu, uint32_t d, uint32_t s)
{
	uint32_t res;	/* all operands in native machine order */

	res = d & s;

	/* set the flags  */
	CLEAR_FLAG(F_OF);
	CLEAR_FLAG(F_CF);
	CLEAR_FLAG(F_AF);
	CONDITIONAL_SET_FLAG(res & 0x80000000, F_SF);
	CONDITIONAL_SET_FLAG(res == 0, F_ZF);
	CONDITIONAL_SET_FLAG(PARITY(res & 0xff), F_PF);
	return res;
}
/****************************************************************************
REMARKS:
Implements the CMP instruction and side effects.
****************************************************************************/
static uint8_t
cmp_byte(struct X86EMU *emu, uint8_t d, uint8_t s)
{
	uint32_t res;	/* all operands in native machine order */
	uint32_t bc;

	res = d - s;
	CLEAR_FLAG(F_CF);
	CONDITIONAL_SET_FLAG(res & 0x80, F_SF);
	CONDITIONAL_SET_FLAG((res & 0xff) == 0, F_ZF);
	CONDITIONAL_SET_FLAG(PARITY(res & 0xff), F_PF);

	/* calculate the borrow chain.  See note at top */
	bc = (res & (~d | s)) | (~d & s);
	CONDITIONAL_SET_FLAG(bc & 0x80, F_CF);
	CONDITIONAL_SET_FLAG(XOR2(bc >> 6), F_OF);
	CONDITIONAL_SET_FLAG(bc & 0x8, F_AF);
	return d;
}

static void
cmp_byte_no_return(struct X86EMU *emu, uint8_t d, uint8_t s)
{
	cmp_byte(emu, d, s);
}
/****************************************************************************
REMARKS:
Implements the CMP instruction and side effects.
****************************************************************************/
static uint16_t
cmp_word(struct X86EMU *emu, uint16_t d, uint16_t s)
{
	uint32_t res;	/* all operands in native machine order */
	uint32_t bc;

	res = d - s;
	CONDITIONAL_SET_FLAG(res & 0x8000, F_SF);
	CONDITIONAL_SET_FLAG((res & 0xffff) == 0, F_ZF);
	CONDITIONAL_SET_FLAG(PARITY(res & 0xff), F_PF);

	/* calculate the borrow chain.  See note at top */
	bc = (res & (~d | s)) | (~d & s);
	CONDITIONAL_SET_FLAG(bc & 0x8000, F_CF);
	CONDITIONAL_SET_FLAG(XOR2(bc >> 14), F_OF);
	CONDITIONAL_SET_FLAG(bc & 0x8, F_AF);
	return d;
}

static void
cmp_word_no_return(struct X86EMU *emu, uint16_t d, uint16_t s)
{
	cmp_word(emu, d, s);
}
/****************************************************************************
REMARKS:
Implements the CMP instruction and side effects.
****************************************************************************/
static uint32_t
cmp_long(struct X86EMU *emu, uint32_t d, uint32_t s)
{
	uint32_t res;	/* all operands in native machine order */
	uint32_t bc;

	res = d - s;
	CONDITIONAL_SET_FLAG(res & 0x80000000, F_SF);
	CONDITIONAL_SET_FLAG((res & 0xffffffff) == 0, F_ZF);
	CONDITIONAL_SET_FLAG(PARITY(res & 0xff), F_PF);

	/* calculate the borrow chain.  See note at top */
	bc = (res & (~d | s)) | (~d & s);
	CONDITIONAL_SET_FLAG(bc & 0x80000000, F_CF);
	CONDITIONAL_SET_FLAG(XOR2(bc >> 30), F_OF);
	CONDITIONAL_SET_FLAG(bc & 0x8, F_AF);
	return d;
}

static void
cmp_long_no_return(struct X86EMU *emu, uint32_t d, uint32_t s)
{
	cmp_long(emu, d, s);
}
/****************************************************************************
REMARKS:
Implements the DAA instruction and side effects.
****************************************************************************/
static uint8_t
daa_byte(struct X86EMU *emu, uint8_t d)
{
	uint32_t res = d;
	if ((d & 0xf) > 9 || ACCESS_FLAG(F_AF)) {
		res += 6;
		SET_FLAG(F_AF);
	}
	if (res > 0x9F || ACCESS_FLAG(F_CF)) {
		res += 0x60;
		SET_FLAG(F_CF);
	}
	CONDITIONAL_SET_FLAG(res & 0x80, F_SF);
	CONDITIONAL_SET_FLAG((res & 0xFF) == 0, F_ZF);
	CONDITIONAL_SET_FLAG(PARITY(res & 0xff), F_PF);
	return (uint8_t) res;
}
/****************************************************************************
REMARKS:
Implements the DAS instruction and side effects.
****************************************************************************/
static uint8_t
das_byte(struct X86EMU *emu, uint8_t d)
{
	if ((d & 0xf) > 9 || ACCESS_FLAG(F_AF)) {
		d -= 6;
		SET_FLAG(F_AF);
	}
	if (d > 0x9F || ACCESS_FLAG(F_CF)) {
		d -= 0x60;
		SET_FLAG(F_CF);
	}
	CONDITIONAL_SET_FLAG(d & 0x80, F_SF);
	CONDITIONAL_SET_FLAG(d == 0, F_ZF);
	CONDITIONAL_SET_FLAG(PARITY(d & 0xff), F_PF);
	return d;
}
/****************************************************************************
REMARKS:
Implements the DEC instruction and side effects.
****************************************************************************/
static uint8_t
dec_byte(struct X86EMU *emu, uint8_t d)
{
	uint32_t res;	/* all operands in native machine order */
	uint32_t bc;

	res = d - 1;
	CONDITIONAL_SET_FLAG(res & 0x80, F_SF);
	CONDITIONAL_SET_FLAG((res & 0xff) == 0, F_ZF);
	CONDITIONAL_SET_FLAG(PARITY(res & 0xff), F_PF);

	/* calculate the borrow chain.  See note at top */
	/* based on sub_byte, uses s==1.  */
	bc = (res & (~d | 1)) | (~d & 1);
	/* carry flag unchanged */
	CONDITIONAL_SET_FLAG(XOR2(bc >> 6), F_OF);
	CONDITIONAL_SET_FLAG(bc & 0x8, F_AF);
	return (uint8_t) res;
}
/****************************************************************************
REMARKS:
Implements the DEC instruction and side effects.
****************************************************************************/
static uint16_t
dec_word(struct X86EMU *emu, uint16_t d)
{
	uint32_t res;	/* all operands in native machine order */
	uint32_t bc;

	res = d - 1;
	CONDITIONAL_SET_FLAG(res & 0x8000, F_SF);
	CONDITIONAL_SET_FLAG((res & 0xffff) == 0, F_ZF);
	CONDITIONAL_SET_FLAG(PARITY(res & 0xff), F_PF);

	/* calculate the borrow chain.  See note at top */
	/* based on the sub_byte routine, with s==1 */
	bc = (res & (~d | 1)) | (~d & 1);
	/* carry flag unchanged */
	CONDITIONAL_SET_FLAG(XOR2(bc >> 14), F_OF);
	CONDITIONAL_SET_FLAG(bc & 0x8, F_AF);
	return (uint16_t) res;
}
/****************************************************************************
REMARKS:
Implements the DEC instruction and side effects.
****************************************************************************/
static uint32_t
dec_long(struct X86EMU *emu, uint32_t d)
{
	uint32_t res;	/* all operands in native machine order */
	uint32_t bc;

	res = d - 1;

	CONDITIONAL_SET_FLAG(res & 0x80000000, F_SF);
	CONDITIONAL_SET_FLAG((res & 0xffffffff) == 0, F_ZF);
	CONDITIONAL_SET_FLAG(PARITY(res & 0xff), F_PF);

	/* calculate the borrow chain.  See note at top */
	bc = (res & (~d | 1)) | (~d & 1);
	/* carry flag unchanged */
	CONDITIONAL_SET_FLAG(XOR2(bc >> 30), F_OF);
	CONDITIONAL_SET_FLAG(bc & 0x8, F_AF);
	return res;
}
/****************************************************************************
REMARKS:
Implements the INC instruction and side effects.
****************************************************************************/
static uint8_t
inc_byte(struct X86EMU *emu, uint8_t d)
{
	uint32_t res;	/* all operands in native machine order */
	uint32_t cc;

	res = d + 1;
	CONDITIONAL_SET_FLAG((res & 0xff) == 0, F_ZF);
	CONDITIONAL_SET_FLAG(res & 0x80, F_SF);
	CONDITIONAL_SET_FLAG(PARITY(res & 0xff), F_PF);

	/* calculate the carry chain  SEE NOTE AT TOP. */
	cc = ((1 & d) | (~res)) & (1 | d);
	CONDITIONAL_SET_FLAG(XOR2(cc >> 6), F_OF);
	CONDITIONAL_SET_FLAG(cc & 0x8, F_AF);
	return (uint8_t) res;
}
/****************************************************************************
REMARKS:
Implements the INC instruction and side effects.
****************************************************************************/
static uint16_t
inc_word(struct X86EMU *emu, uint16_t d)
{
	uint32_t res;	/* all operands in native machine order */
	uint32_t cc;

	res = d + 1;
	CONDITIONAL_SET_FLAG((res & 0xffff) == 0, F_ZF);
	CONDITIONAL_SET_FLAG(res & 0x8000, F_SF);
	CONDITIONAL_SET_FLAG(PARITY(res & 0xff), F_PF);

	/* calculate the carry chain  SEE NOTE AT TOP. */
	cc = (1 & d) | ((~res) & (1 | d));
	CONDITIONAL_SET_FLAG(XOR2(cc >> 14), F_OF);
	CONDITIONAL_SET_FLAG(cc & 0x8, F_AF);
	return (uint16_t) res;
}
/****************************************************************************
REMARKS:
Implements the INC instruction and side effects.
****************************************************************************/
static uint32_t
inc_long(struct X86EMU *emu, uint32_t d)
{
	uint32_t res;	/* all operands in native machine order */
	uint32_t cc;

	res = d + 1;
	CONDITIONAL_SET_FLAG((res & 0xffffffff) == 0, F_ZF);
	CONDITIONAL_SET_FLAG(res & 0x80000000, F_SF);
	CONDITIONAL_SET_FLAG(PARITY(res & 0xff), F_PF);

	/* calculate the carry chain  SEE NOTE AT TOP. */
	cc = (1 & d) | ((~res) & (1 | d));
	CONDITIONAL_SET_FLAG(XOR2(cc >> 30), F_OF);
	CONDITIONAL_SET_FLAG(cc & 0x8, F_AF);
	return res;
}
/****************************************************************************
REMARKS:
Implements the OR instruction and side effects.
****************************************************************************/
static uint8_t
or_byte(struct X86EMU *emu, uint8_t d, uint8_t s)
{
	uint8_t res;	/* all operands in native machine order */

	res = d | s;
	CLEAR_FLAG(F_OF);
	CLEAR_FLAG(F_CF);
	CLEAR_FLAG(F_AF);
	CONDITIONAL_SET_FLAG(res & 0x80, F_SF);
	CONDITIONAL_SET_FLAG(res == 0, F_ZF);
	CONDITIONAL_SET_FLAG(PARITY(res), F_PF);
	return res;
}
/****************************************************************************
REMARKS:
Implements the OR instruction and side effects.
****************************************************************************/
static uint16_t
or_word(struct X86EMU *emu, uint16_t d, uint16_t s)
{
	uint16_t res;	/* all operands in native machine order */

	res = d | s;
	/* set the carry flag to be bit 8 */
	CLEAR_FLAG(F_OF);
	CLEAR_FLAG(F_CF);
	CLEAR_FLAG(F_AF);
	CONDITIONAL_SET_FLAG(res & 0x8000, F_SF);
	CONDITIONAL_SET_FLAG(res == 0, F_ZF);
	CONDITIONAL_SET_FLAG(PARITY(res & 0xff), F_PF);
	return res;
}
/****************************************************************************
REMARKS:
Implements the OR instruction and side effects.
****************************************************************************/
static uint32_t
or_long(struct X86EMU *emu, uint32_t d, uint32_t s)
{
	uint32_t res;	/* all operands in native machine order */

	res = d | s;

	/* set the carry flag to be bit 8 */
	CLEAR_FLAG(F_OF);
	CLEAR_FLAG(F_CF);
	CLEAR_FLAG(F_AF);
	CONDITIONAL_SET_FLAG(res & 0x80000000, F_SF);
	CONDITIONAL_SET_FLAG(res == 0, F_ZF);
	CONDITIONAL_SET_FLAG(PARITY(res & 0xff), F_PF);
	return res;
}
/****************************************************************************
REMARKS:
Implements the OR instruction and side effects.
****************************************************************************/
static uint8_t
neg_byte(struct X86EMU *emu, uint8_t s)
{
	uint8_t res;
	uint8_t bc;

	CONDITIONAL_SET_FLAG(s != 0, F_CF);
	res = (uint8_t) - s;
	CONDITIONAL_SET_FLAG((res & 0xff) == 0, F_ZF);
	CONDITIONAL_SET_FLAG(res & 0x80, F_SF);
	CONDITIONAL_SET_FLAG(PARITY(res), F_PF);
	/* calculate the borrow chain --- modified such that d=0.
	 * substitutiing d=0 into     bc= res&(~d|s)|(~d&s); (the one used for
	 * sub) and simplifying, since ~d=0xff..., ~d|s == 0xffff..., and
	 * res&0xfff... == res.  Similarly ~d&s == s.  So the simplified
	 * result is: */
	bc = res | s;
	CONDITIONAL_SET_FLAG(XOR2(bc >> 6), F_OF);
	CONDITIONAL_SET_FLAG(bc & 0x8, F_AF);
	return res;
}
/****************************************************************************
REMARKS:
Implements the OR instruction and side effects.
****************************************************************************/
static uint16_t
neg_word(struct X86EMU *emu, uint16_t s)
{
	uint16_t res;
	uint16_t bc;

	CONDITIONAL_SET_FLAG(s != 0, F_CF);
	res = (uint16_t) - s;
	CONDITIONAL_SET_FLAG((res & 0xffff) == 0, F_ZF);
	CONDITIONAL_SET_FLAG(res & 0x8000, F_SF);
	CONDITIONAL_SET_FLAG(PARITY(res & 0xff), F_PF);

	/* calculate the borrow chain --- modified such that d=0.
	 * substitutiing d=0 into     bc= res&(~d|s)|(~d&s); (the one used for
	 * sub) and simplifying, since ~d=0xff..., ~d|s == 0xffff..., and
	 * res&0xfff... == res.  Similarly ~d&s == s.  So the simplified
	 * result is: */
	bc = res | s;
	CONDITIONAL_SET_FLAG(XOR2(bc >> 14), F_OF);
	CONDITIONAL_SET_FLAG(bc & 0x8, F_AF);
	return res;
}
/****************************************************************************
REMARKS:
Implements the OR instruction and side effects.
****************************************************************************/
static uint32_t
neg_long(struct X86EMU *emu, uint32_t s)
{
	uint32_t res;
	uint32_t bc;

	CONDITIONAL_SET_FLAG(s != 0, F_CF);
	res = (uint32_t) - s;
	CONDITIONAL_SET_FLAG((res & 0xffffffff) == 0, F_ZF);
	CONDITIONAL_SET_FLAG(res & 0x80000000, F_SF);
	CONDITIONAL_SET_FLAG(PARITY(res & 0xff), F_PF);

	/* calculate the borrow chain --- modified such that d=0.
	 * substitutiing d=0 into     bc= res&(~d|s)|(~d&s); (the one used for
	 * sub) and simplifying, since ~d=0xff..., ~d|s == 0xffff..., and
	 * res&0xfff... == res.  Similarly ~d&s == s.  So the simplified
	 * result is: */
	bc = res | s;
	CONDITIONAL_SET_FLAG(XOR2(bc >> 30), F_OF);
	CONDITIONAL_SET_FLAG(bc & 0x8, F_AF);
	return res;
}
/****************************************************************************
REMARKS:
Implements the RCL instruction and side effects.
****************************************************************************/
static uint8_t
rcl_byte(struct X86EMU *emu, uint8_t d, uint8_t s)
{
	unsigned int res, cnt, mask, cf;

	/* s is the rotate distance.  It varies from 0 - 8. */
	/* have
	 *
	 * CF  B_7 B_6 B_5 B_4 B_3 B_2 B_1 B_0
	 *
	 * want to rotate through the carry by "s" bits.  We could loop, but
	 * that's inefficient.  So the width is 9, and we split into three
	 * parts:
	 *
	 * The new carry flag   (was B_n) the stuff in B_n-1 .. B_0 the stuff in
	 * B_7 .. B_n+1
	 *
	 * The new rotate is done mod 9, and given this, for a rotation of n bits
	 * (mod 9) the new carry flag is then located n bits from the MSB.
	 * The low part is then shifted up cnt bits, and the high part is or'd
	 * in.  Using CAPS for new values, and lowercase for the original
	 * values, this can be expressed as:
	 *
	 * IF n > 0 1) CF <-  b_(8-n) 2) B_(7) .. B_(n)  <-  b_(8-(n+1)) .. b_0
	 * 3) B_(n-1) <- cf 4) B_(n-2) .. B_0 <-  b_7 .. b_(8-(n-1)) */
	res = d;
	if ((cnt = s % 9) != 0) {
		/* extract the new CARRY FLAG. */
		/* CF <-  b_(8-n)             */
		cf = (d >> (8 - cnt)) & 0x1;

		/* get the low stuff which rotated into the range B_7 .. B_cnt */
		/* B_(7) .. B_(n)  <-  b_(8-(n+1)) .. b_0  */
		/* note that the right hand side done by the mask */
		res = (d << cnt) & 0xff;

		/* now the high stuff which rotated around into the positions
		 * B_cnt-2 .. B_0 */
		/* B_(n-2) .. B_0 <-  b_7 .. b_(8-(n-1)) */
		/* shift it downward, 7-(n-2) = 9-n positions. and mask off
		 * the result before or'ing in. */
		mask = (1 << (cnt - 1)) - 1;
		res |= (d >> (9 - cnt)) & mask;

		/* if the carry flag was set, or it in.  */
		if (ACCESS_FLAG(F_CF)) {	/* carry flag is set */
			/* B_(n-1) <- cf */
			res |= 1 << (cnt - 1);
		}
		/* set the new carry flag, based on the variable "cf" */
		CONDITIONAL_SET_FLAG(cf, F_CF);
		/* OVERFLOW is set *IFF* cnt==1, then it is the xor of CF and
		 * the most significant bit.  Blecck. */
		/* parenthesized this expression since it appears to be
		 * causing OF to be misset */
		CONDITIONAL_SET_FLAG(cnt == 1 && XOR2(cf + ((res >> 6) & 0x2)),
		    F_OF);

	}
	return (uint8_t) res;
}
/****************************************************************************
REMARKS:
Implements the RCL instruction and side effects.
****************************************************************************/
static uint16_t
rcl_word(struct X86EMU *emu, uint16_t d, uint8_t s)
{
	unsigned int res, cnt, mask, cf;

	res = d;
	if ((cnt = s % 17) != 0) {
		cf = (d >> (16 - cnt)) & 0x1;
		res = (d << cnt) & 0xffff;
		mask = (1 << (cnt - 1)) - 1;
		res |= (d >> (17 - cnt)) & mask;
		if (ACCESS_FLAG(F_CF)) {
			res |= 1 << (cnt - 1);
		}
		CONDITIONAL_SET_FLAG(cf, F_CF);
		CONDITIONAL_SET_FLAG(cnt == 1 && XOR2(cf + ((res >> 14) & 0x2)),
		    F_OF);
	}
	return (uint16_t) res;
}
/****************************************************************************
REMARKS:
Implements the RCL instruction and side effects.
****************************************************************************/
static uint32_t
rcl_long(struct X86EMU *emu, uint32_t d, uint8_t s)
{
	uint32_t res, cnt, mask, cf;

	res = d;
	if ((cnt = s % 33) != 0) {
		cf = (d >> (32 - cnt)) & 0x1;
		res = (d << cnt) & 0xffffffff;
		mask = (1 << (cnt - 1)) - 1;
		res |= (d >> (33 - cnt)) & mask;
		if (ACCESS_FLAG(F_CF)) {	/* carry flag is set */
			res |= 1 << (cnt - 1);
		}
		CONDITIONAL_SET_FLAG(cf, F_CF);
		CONDITIONAL_SET_FLAG(cnt == 1 && XOR2(cf + ((res >> 30) & 0x2)),
		    F_OF);
	}
	return res;
}
/****************************************************************************
REMARKS:
Implements the RCR instruction and side effects.
****************************************************************************/
static uint8_t
rcr_byte(struct X86EMU *emu, uint8_t d, uint8_t s)
{
	uint32_t res, cnt;
	uint32_t mask, cf, ocf = 0;

	/* rotate right through carry */
	/* s is the rotate distance.  It varies from 0 - 8. d is the byte
	 * object rotated.
	 *
	 * have
	 *
	 * CF  B_7 B_6 B_5 B_4 B_3 B_2 B_1 B_0
	 *
	 * The new rotate is done mod 9, and given this, for a rotation of n bits
	 * (mod 9) the new carry flag is then located n bits from the LSB.
	 * The low part is then shifted up cnt bits, and the high part is or'd
	 * in.  Using CAPS for new values, and lowercase for the original
	 * values, this can be expressed as:
	 *
	 * IF n > 0 1) CF <-  b_(n-1) 2) B_(8-(n+1)) .. B_(0)  <-  b_(7) .. b_(n)
	 * 3) B_(8-n) <- cf 4) B_(7) .. B_(8-(n-1)) <-  b_(n-2) .. b_(0) */
	res = d;
	if ((cnt = s % 9) != 0) {
		/* extract the new CARRY FLAG. */
		/* CF <-  b_(n-1)              */
		if (cnt == 1) {
			cf = d & 0x1;
			/* note hackery here.  Access_flag(..) evaluates to
			 * either 0 if flag not set non-zero if flag is set.
			 * doing access_flag(..) != 0 casts that into either
			 * 0..1 in any representation of the flags register
			 * (i.e. packed bit array or unpacked.) */
			ocf = ACCESS_FLAG(F_CF) != 0;
		} else
			cf = (d >> (cnt - 1)) & 0x1;

		/* B_(8-(n+1)) .. B_(0)  <-  b_(7) .. b_n  */
		/* note that the right hand side done by the mask This is
		 * effectively done by shifting the object to the right.  The
		 * result must be masked, in case the object came in and was
		 * treated as a negative number.  Needed??? */

		mask = (1 << (8 - cnt)) - 1;
		res = (d >> cnt) & mask;

		/* now the high stuff which rotated around into the positions
		 * B_cnt-2 .. B_0 */
		/* B_(7) .. B_(8-(n-1)) <-  b_(n-2) .. b_(0) */
		/* shift it downward, 7-(n-2) = 9-n positions. and mask off
		 * the result before or'ing in. */
		res |= (d << (9 - cnt));

		/* if the carry flag was set, or it in.  */
		if (ACCESS_FLAG(F_CF)) {	/* carry flag is set */
			/* B_(8-n) <- cf */
			res |= 1 << (8 - cnt);
		}
		/* set the new carry flag, based on the variable "cf" */
		CONDITIONAL_SET_FLAG(cf, F_CF);
		/* OVERFLOW is set *IFF* cnt==1, then it is the xor of CF and
		 * the most significant bit.  Blecck. */
		/* parenthesized... */
		if (cnt == 1) {
			CONDITIONAL_SET_FLAG(XOR2(ocf + ((d >> 6) & 0x2)),
			    F_OF);
		}
	}
	return (uint8_t) res;
}
/****************************************************************************
REMARKS:
Implements the RCR instruction and side effects.
****************************************************************************/
static uint16_t
rcr_word(struct X86EMU *emu, uint16_t d, uint8_t s)
{
	uint32_t res, cnt;
	uint32_t mask, cf, ocf = 0;

	/* rotate right through carry */
	res = d;
	if ((cnt = s % 17) != 0) {
		if (cnt == 1) {
			cf = d & 0x1;
			ocf = ACCESS_FLAG(F_CF) != 0;
		} else
			cf = (d >> (cnt - 1)) & 0x1;
		mask = (1 << (16 - cnt)) - 1;
		res = (d >> cnt) & mask;
		res |= (d << (17 - cnt));
		if (ACCESS_FLAG(F_CF)) {
			res |= 1 << (16 - cnt);
		}
		CONDITIONAL_SET_FLAG(cf, F_CF);
		if (cnt == 1) {
			CONDITIONAL_SET_FLAG(XOR2(ocf + ((d >> 14) & 0x2)),
			    F_OF);
		}
	}
	return (uint16_t) res;
}
/****************************************************************************
REMARKS:
Implements the RCR instruction and side effects.
****************************************************************************/
static uint32_t
rcr_long(struct X86EMU *emu, uint32_t d, uint8_t s)
{
	uint32_t res, cnt;
	uint32_t mask, cf, ocf = 0;

	/* rotate right through carry */
	res = d;
	if ((cnt = s % 33) != 0) {
		if (cnt == 1) {
			cf = d & 0x1;
			ocf = ACCESS_FLAG(F_CF) != 0;
		} else
			cf = (d >> (cnt - 1)) & 0x1;
		mask = (1 << (32 - cnt)) - 1;
		res = (d >> cnt) & mask;
		if (cnt != 1)
			res |= (d << (33 - cnt));
		if (ACCESS_FLAG(F_CF)) {	/* carry flag is set */
			res |= 1 << (32 - cnt);
		}
		CONDITIONAL_SET_FLAG(cf, F_CF);
		if (cnt == 1) {
			CONDITIONAL_SET_FLAG(XOR2(ocf + ((d >> 30) & 0x2)),
			    F_OF);
		}
	}
	return res;
}
/****************************************************************************
REMARKS:
Implements the ROL instruction and side effects.
****************************************************************************/
static uint8_t
rol_byte(struct X86EMU *emu, uint8_t d, uint8_t s)
{
	unsigned int res, cnt, mask;

	/* rotate left */
	/* s is the rotate distance.  It varies from 0 - 8. d is the byte
	 * object rotated.
	 *
	 * have
	 *
	 * CF  B_7 ... B_0
	 *
	 * The new rotate is done mod 8. Much simpler than the "rcl" or "rcr"
	 * operations.
	 *
	 * IF n > 0 1) B_(7) .. B_(n)  <-  b_(8-(n+1)) .. b_(0) 2) B_(n-1) ..
	 * B_(0) <-  b_(7) .. b_(8-n) */
	res = d;
	if ((cnt = s % 8) != 0) {
		/* B_(7) .. B_(n)  <-  b_(8-(n+1)) .. b_(0) */
		res = (d << cnt);

		/* B_(n-1) .. B_(0) <-  b_(7) .. b_(8-n) */
		mask = (1 << cnt) - 1;
		res |= (d >> (8 - cnt)) & mask;

		/* set the new carry flag, Note that it is the low order bit
		 * of the result!!!                               */
		CONDITIONAL_SET_FLAG(res & 0x1, F_CF);
		/* OVERFLOW is set *IFF* s==1, then it is the xor of CF and
		 * the most significant bit.  Blecck. */
		CONDITIONAL_SET_FLAG(s == 1 &&
		    XOR2((res & 0x1) + ((res >> 6) & 0x2)),
		    F_OF);
	} if (s != 0) {
		/* set the new carry flag, Note that it is the low order bit
		 * of the result!!!                               */
		CONDITIONAL_SET_FLAG(res & 0x1, F_CF);
	}
	return (uint8_t) res;
}
/****************************************************************************
REMARKS:
Implements the ROL instruction and side effects.
****************************************************************************/
static uint16_t
rol_word(struct X86EMU *emu, uint16_t d, uint8_t s)
{
	unsigned int res, cnt, mask;

	res = d;
	if ((cnt = s % 16) != 0) {
		res = (d << cnt);
		mask = (1 << cnt) - 1;
		res |= (d >> (16 - cnt)) & mask;
		CONDITIONAL_SET_FLAG(res & 0x1, F_CF);
		CONDITIONAL_SET_FLAG(s == 1 &&
		    XOR2((res & 0x1) + ((res >> 14) & 0x2)),
		    F_OF);
	} if (s != 0) {
		/* set the new carry flag, Note that it is the low order bit
		 * of the result!!!                               */
		CONDITIONAL_SET_FLAG(res & 0x1, F_CF);
	}
	return (uint16_t) res;
}
/****************************************************************************
REMARKS:
Implements the ROL instruction and side effects.
****************************************************************************/
static uint32_t
rol_long(struct X86EMU *emu, uint32_t d, uint8_t s)
{
	uint32_t res, cnt, mask;

	res = d;
	if ((cnt = s % 32) != 0) {
		res = (d << cnt);
		mask = (1 << cnt) - 1;
		res |= (d >> (32 - cnt)) & mask;
		CONDITIONAL_SET_FLAG(res & 0x1, F_CF);
		CONDITIONAL_SET_FLAG(s == 1 &&
		    XOR2((res & 0x1) + ((res >> 30) & 0x2)),
		    F_OF);
	} if (s != 0) {
		/* set the new carry flag, Note that it is the low order bit
		 * of the result!!!                               */
		CONDITIONAL_SET_FLAG(res & 0x1, F_CF);
	}
	return res;
}
/****************************************************************************
REMARKS:
Implements the ROR instruction and side effects.
****************************************************************************/
static uint8_t
ror_byte(struct X86EMU *emu, uint8_t d, uint8_t s)
{
	unsigned int res, cnt, mask;

	/* rotate right */
	/* s is the rotate distance.  It varies from 0 - 8. d is the byte
	 * object rotated.
	 *
	 * have
	 *
	 * B_7 ... B_0
	 *
	 * The rotate is done mod 8.
	 *
	 * IF n > 0 1) B_(8-(n+1)) .. B_(0)  <-  b_(7) .. b_(n) 2) B_(7) ..
	 * B_(8-n) <-  b_(n-1) .. b_(0) */
	res = d;
	if ((cnt = s % 8) != 0) {	/* not a typo, do nada if cnt==0 */
		/* B_(7) .. B_(8-n) <-  b_(n-1) .. b_(0) */
		res = (d << (8 - cnt));

		/* B_(8-(n+1)) .. B_(0)  <-  b_(7) .. b_(n) */
		mask = (1 << (8 - cnt)) - 1;
		res |= (d >> (cnt)) & mask;

		/* set the new carry flag, Note that it is the low order bit
		 * of the result!!!                               */
		CONDITIONAL_SET_FLAG(res & 0x80, F_CF);
		/* OVERFLOW is set *IFF* s==1, then it is the xor of the two
		 * most significant bits.  Blecck. */
		CONDITIONAL_SET_FLAG(s == 1 && XOR2(res >> 6), F_OF);
	} else if (s != 0) {
		/* set the new carry flag, Note that it is the low order bit
		 * of the result!!!                               */
		CONDITIONAL_SET_FLAG(res & 0x80, F_CF);
	}
	return (uint8_t) res;
}
/****************************************************************************
REMARKS:
Implements the ROR instruction and side effects.
****************************************************************************/
static uint16_t
ror_word(struct X86EMU *emu, uint16_t d, uint8_t s)
{
	unsigned int res, cnt, mask;

	res = d;
	if ((cnt = s % 16) != 0) {
		res = (d << (16 - cnt));
		mask = (1 << (16 - cnt)) - 1;
		res |= (d >> (cnt)) & mask;
		CONDITIONAL_SET_FLAG(res & 0x8000, F_CF);
		CONDITIONAL_SET_FLAG(s == 1 && XOR2(res >> 14), F_OF);
	} else if (s != 0) {
		/* set the new carry flag, Note that it is the low order bit
		 * of the result!!!                               */
		CONDITIONAL_SET_FLAG(res & 0x8000, F_CF);
	}
	return (uint16_t) res;
}
/****************************************************************************
REMARKS:
Implements the ROR instruction and side effects.
****************************************************************************/
static uint32_t
ror_long(struct X86EMU *emu, uint32_t d, uint8_t s)
{
	uint32_t res, cnt, mask;

	res = d;
	if ((cnt = s % 32) != 0) {
		res = (d << (32 - cnt));
		mask = (1 << (32 - cnt)) - 1;
		res |= (d >> (cnt)) & mask;
		CONDITIONAL_SET_FLAG(res & 0x80000000, F_CF);
		CONDITIONAL_SET_FLAG(s == 1 && XOR2(res >> 30), F_OF);
	} else if (s != 0) {
		/* set the new carry flag, Note that it is the low order bit
		 * of the result!!!                               */
		CONDITIONAL_SET_FLAG(res & 0x80000000, F_CF);
	}
	return res;
}
/****************************************************************************
REMARKS:
Implements the SHL instruction and side effects.
****************************************************************************/
static uint8_t
shl_byte(struct X86EMU *emu, uint8_t d, uint8_t s)
{
	unsigned int cnt, res, cf;

	if (s < 8) {
		cnt = s % 8;

		/* last bit shifted out goes into carry flag */
		if (cnt > 0) {
			res = d << cnt;
			cf = d & (1 << (8 - cnt));
			CONDITIONAL_SET_FLAG(cf, F_CF);
			CONDITIONAL_SET_FLAG((res & 0xff) == 0, F_ZF);
			CONDITIONAL_SET_FLAG(res & 0x80, F_SF);
			CONDITIONAL_SET_FLAG(PARITY(res & 0xff), F_PF);
		} else {
			res = (uint8_t) d;
		}

		if (cnt == 1) {
			/* Needs simplification. */
			CONDITIONAL_SET_FLAG(
			    (((res & 0x80) == 0x80) ^
				(ACCESS_FLAG(F_CF) != 0)),
			/* was (emu->x86.R_FLG&F_CF)==F_CF)), */
			    F_OF);
		} else {
			CLEAR_FLAG(F_OF);
		}
	} else {
		res = 0;
		CONDITIONAL_SET_FLAG((d << (s - 1)) & 0x80, F_CF);
		CLEAR_FLAG(F_OF);
		CLEAR_FLAG(F_SF);
		SET_FLAG(F_PF);
		SET_FLAG(F_ZF);
	}
	return (uint8_t) res;
}
/****************************************************************************
REMARKS:
Implements the SHL instruction and side effects.
****************************************************************************/
static uint16_t
shl_word(struct X86EMU *emu, uint16_t d, uint8_t s)
{
	unsigned int cnt, res, cf;

	if (s < 16) {
		cnt = s % 16;
		if (cnt > 0) {
			res = d << cnt;
			cf = d & (1 << (16 - cnt));
			CONDITIONAL_SET_FLAG(cf, F_CF);
			CONDITIONAL_SET_FLAG((res & 0xffff) == 0, F_ZF);
			CONDITIONAL_SET_FLAG(res & 0x8000, F_SF);
			CONDITIONAL_SET_FLAG(PARITY(res & 0xff), F_PF);
		} else {
			res = (uint16_t) d;
		}

		if (cnt == 1) {
			CONDITIONAL_SET_FLAG(
			    (((res & 0x8000) == 0x8000) ^
				(ACCESS_FLAG(F_CF) != 0)),
			    F_OF);
		} else {
			CLEAR_FLAG(F_OF);
		}
	} else {
		res = 0;
		CONDITIONAL_SET_FLAG((d << (s - 1)) & 0x8000, F_CF);
		CLEAR_FLAG(F_OF);
		CLEAR_FLAG(F_SF);
		SET_FLAG(F_PF);
		SET_FLAG(F_ZF);
	}
	return (uint16_t) res;
}
/****************************************************************************
REMARKS:
Implements the SHL instruction and side effects.
****************************************************************************/
static uint32_t
shl_long(struct X86EMU *emu, uint32_t d, uint8_t s)
{
	unsigned int cnt, res, cf;

	if (s < 32) {
		cnt = s % 32;
		if (cnt > 0) {
			res = d << cnt;
			cf = d & (1 << (32 - cnt));
			CONDITIONAL_SET_FLAG(cf, F_CF);
			CONDITIONAL_SET_FLAG((res & 0xffffffff) == 0, F_ZF);
			CONDITIONAL_SET_FLAG(res & 0x80000000, F_SF);
			CONDITIONAL_SET_FLAG(PARITY(res & 0xff), F_PF);
		} else {
			res = d;
		}
		if (cnt == 1) {
			CONDITIONAL_SET_FLAG((((res & 0x80000000) == 0x80000000) ^
				(ACCESS_FLAG(F_CF) != 0)), F_OF);
		} else {
			CLEAR_FLAG(F_OF);
		}
	} else {
		res = 0;
		CONDITIONAL_SET_FLAG((d << (s - 1)) & 0x80000000, F_CF);
		CLEAR_FLAG(F_OF);
		CLEAR_FLAG(F_SF);
		SET_FLAG(F_PF);
		SET_FLAG(F_ZF);
	}
	return res;
}
/****************************************************************************
REMARKS:
Implements the SHR instruction and side effects.
****************************************************************************/
static uint8_t
shr_byte(struct X86EMU *emu, uint8_t d, uint8_t s)
{
	unsigned int cnt, res, cf;

	if (s < 8) {
		cnt = s % 8;
		if (cnt > 0) {
			cf = d & (1 << (cnt - 1));
			res = d >> cnt;
			CONDITIONAL_SET_FLAG(cf, F_CF);
			CONDITIONAL_SET_FLAG((res & 0xff) == 0, F_ZF);
			CONDITIONAL_SET_FLAG(res & 0x80, F_SF);
			CONDITIONAL_SET_FLAG(PARITY(res & 0xff), F_PF);
		} else {
			res = (uint8_t) d;
		}

		if (cnt == 1) {
			CONDITIONAL_SET_FLAG(XOR2(res >> 6), F_OF);
		} else {
			CLEAR_FLAG(F_OF);
		}
	} else {
		res = 0;
		CONDITIONAL_SET_FLAG((d >> (s - 1)) & 0x1, F_CF);
		CLEAR_FLAG(F_OF);
		CLEAR_FLAG(F_SF);
		SET_FLAG(F_PF);
		SET_FLAG(F_ZF);
	}
	return (uint8_t) res;
}
/****************************************************************************
REMARKS:
Implements the SHR instruction and side effects.
****************************************************************************/
static uint16_t
shr_word(struct X86EMU *emu, uint16_t d, uint8_t s)
{
	unsigned int cnt, res, cf;

	if (s < 16) {
		cnt = s % 16;
		if (cnt > 0) {
			cf = d & (1 << (cnt - 1));
			res = d >> cnt;
			CONDITIONAL_SET_FLAG(cf, F_CF);
			CONDITIONAL_SET_FLAG((res & 0xffff) == 0, F_ZF);
			CONDITIONAL_SET_FLAG(res & 0x8000, F_SF);
			CONDITIONAL_SET_FLAG(PARITY(res & 0xff), F_PF);
		} else {
			res = d;
		}

		if (cnt == 1) {
			CONDITIONAL_SET_FLAG(XOR2(res >> 14), F_OF);
		} else {
			CLEAR_FLAG(F_OF);
		}
	} else {
		res = 0;
		CLEAR_FLAG(F_CF);
		CLEAR_FLAG(F_OF);
		SET_FLAG(F_ZF);
		CLEAR_FLAG(F_SF);
		CLEAR_FLAG(F_PF);
	}
	return (uint16_t) res;
}
/****************************************************************************
REMARKS:
Implements the SHR instruction and side effects.
****************************************************************************/
static uint32_t
shr_long(struct X86EMU *emu, uint32_t d, uint8_t s)
{
	unsigned int cnt, res, cf;

	if (s < 32) {
		cnt = s % 32;
		if (cnt > 0) {
			cf = d & (1 << (cnt - 1));
			res = d >> cnt;
			CONDITIONAL_SET_FLAG(cf, F_CF);
			CONDITIONAL_SET_FLAG((res & 0xffffffff) == 0, F_ZF);
			CONDITIONAL_SET_FLAG(res & 0x80000000, F_SF);
			CONDITIONAL_SET_FLAG(PARITY(res & 0xff), F_PF);
		} else {
			res = d;
		}
		if (cnt == 1) {
			CONDITIONAL_SET_FLAG(XOR2(res >> 30), F_OF);
		} else {
			CLEAR_FLAG(F_OF);
		}
	} else {
		res = 0;
		CLEAR_FLAG(F_CF);
		CLEAR_FLAG(F_OF);
		SET_FLAG(F_ZF);
		CLEAR_FLAG(F_SF);
		CLEAR_FLAG(F_PF);
	}
	return res;
}
/****************************************************************************
REMARKS:
Implements the SAR instruction and side effects.
****************************************************************************/
static uint8_t
sar_byte(struct X86EMU *emu, uint8_t d, uint8_t s)
{
	unsigned int cnt, res, cf, mask, sf;

	res = d;
	sf = d & 0x80;
	cnt = s % 8;
	if (cnt > 0 && cnt < 8) {
		mask = (1 << (8 - cnt)) - 1;
		cf = d & (1 << (cnt - 1));
		res = (d >> cnt) & mask;
		CONDITIONAL_SET_FLAG(cf, F_CF);
		if (sf) {
			res |= ~mask;
		}
		CONDITIONAL_SET_FLAG((res & 0xff) == 0, F_ZF);
		CONDITIONAL_SET_FLAG(PARITY(res & 0xff), F_PF);
		CONDITIONAL_SET_FLAG(res & 0x80, F_SF);
	} else if (cnt >= 8) {
		if (sf) {
			res = 0xff;
			SET_FLAG(F_CF);
			CLEAR_FLAG(F_ZF);
			SET_FLAG(F_SF);
			SET_FLAG(F_PF);
		} else {
			res = 0;
			CLEAR_FLAG(F_CF);
			SET_FLAG(F_ZF);
			CLEAR_FLAG(F_SF);
			CLEAR_FLAG(F_PF);
		}
	}
	return (uint8_t) res;
}
/****************************************************************************
REMARKS:
Implements the SAR instruction and side effects.
****************************************************************************/
static uint16_t
sar_word(struct X86EMU *emu, uint16_t d, uint8_t s)
{
	unsigned int cnt, res, cf, mask, sf;

	sf = d & 0x8000;
	cnt = s % 16;
	res = d;
	if (cnt > 0 && cnt < 16) {
		mask = (1 << (16 - cnt)) - 1;
		cf = d & (1 << (cnt - 1));
		res = (d >> cnt) & mask;
		CONDITIONAL_SET_FLAG(cf, F_CF);
		if (sf) {
			res |= ~mask;
		}
		CONDITIONAL_SET_FLAG((res & 0xffff) == 0, F_ZF);
		CONDITIONAL_SET_FLAG(res & 0x8000, F_SF);
		CONDITIONAL_SET_FLAG(PARITY(res & 0xff), F_PF);
	} else if (cnt >= 16) {
		if (sf) {
			res = 0xffff;
			SET_FLAG(F_CF);
			CLEAR_FLAG(F_ZF);
			SET_FLAG(F_SF);
			SET_FLAG(F_PF);
		} else {
			res = 0;
			CLEAR_FLAG(F_CF);
			SET_FLAG(F_ZF);
			CLEAR_FLAG(F_SF);
			CLEAR_FLAG(F_PF);
		}
	}
	return (uint16_t) res;
}
/****************************************************************************
REMARKS:
Implements the SAR instruction and side effects.
****************************************************************************/
static uint32_t
sar_long(struct X86EMU *emu, uint32_t d, uint8_t s)
{
	uint32_t cnt, res, cf, mask, sf;

	sf = d & 0x80000000;
	cnt = s % 32;
	res = d;
	if (cnt > 0 && cnt < 32) {
		mask = (1 << (32 - cnt)) - 1;
		cf = d & (1 << (cnt - 1));
		res = (d >> cnt) & mask;
		CONDITIONAL_SET_FLAG(cf, F_CF);
		if (sf) {
			res |= ~mask;
		}
		CONDITIONAL_SET_FLAG((res & 0xffffffff) == 0, F_ZF);
		CONDITIONAL_SET_FLAG(res & 0x80000000, F_SF);
		CONDITIONAL_SET_FLAG(PARITY(res & 0xff), F_PF);
	} else if (cnt >= 32) {
		if (sf) {
			res = 0xffffffff;
			SET_FLAG(F_CF);
			CLEAR_FLAG(F_ZF);
			SET_FLAG(F_SF);
			SET_FLAG(F_PF);
		} else {
			res = 0;
			CLEAR_FLAG(F_CF);
			SET_FLAG(F_ZF);
			CLEAR_FLAG(F_SF);
			CLEAR_FLAG(F_PF);
		}
	}
	return res;
}
/****************************************************************************
REMARKS:
Implements the SHLD instruction and side effects.
****************************************************************************/
static uint16_t
shld_word(struct X86EMU *emu, uint16_t d, uint16_t fill, uint8_t s)
{
	unsigned int cnt, res, cf;

	if (s < 16) {
		cnt = s % 16;
		if (cnt > 0) {
			res = (d << cnt) | (fill >> (16 - cnt));
			cf = d & (1 << (16 - cnt));
			CONDITIONAL_SET_FLAG(cf, F_CF);
			CONDITIONAL_SET_FLAG((res & 0xffff) == 0, F_ZF);
			CONDITIONAL_SET_FLAG(res & 0x8000, F_SF);
			CONDITIONAL_SET_FLAG(PARITY(res & 0xff), F_PF);
		} else {
			res = d;
		}
		if (cnt == 1) {
			CONDITIONAL_SET_FLAG((((res & 0x8000) == 0x8000) ^
				(ACCESS_FLAG(F_CF) != 0)), F_OF);
		} else {
			CLEAR_FLAG(F_OF);
		}
	} else {
		res = 0;
		CONDITIONAL_SET_FLAG((d << (s - 1)) & 0x8000, F_CF);
		CLEAR_FLAG(F_OF);
		CLEAR_FLAG(F_SF);
		SET_FLAG(F_PF);
		SET_FLAG(F_ZF);
	}
	return (uint16_t) res;
}
/****************************************************************************
REMARKS:
Implements the SHLD instruction and side effects.
****************************************************************************/
static uint32_t
shld_long(struct X86EMU *emu, uint32_t d, uint32_t fill, uint8_t s)
{
	unsigned int cnt, res, cf;

	if (s < 32) {
		cnt = s % 32;
		if (cnt > 0) {
			res = (d << cnt) | (fill >> (32 - cnt));
			cf = d & (1 << (32 - cnt));
			CONDITIONAL_SET_FLAG(cf, F_CF);
			CONDITIONAL_SET_FLAG((res & 0xffffffff) == 0, F_ZF);
			CONDITIONAL_SET_FLAG(res & 0x80000000, F_SF);
			CONDITIONAL_SET_FLAG(PARITY(res & 0xff), F_PF);
		} else {
			res = d;
		}
		if (cnt == 1) {
			CONDITIONAL_SET_FLAG((((res & 0x80000000) == 0x80000000) ^
				(ACCESS_FLAG(F_CF) != 0)), F_OF);
		} else {
			CLEAR_FLAG(F_OF);
		}
	} else {
		res = 0;
		CONDITIONAL_SET_FLAG((d << (s - 1)) & 0x80000000, F_CF);
		CLEAR_FLAG(F_OF);
		CLEAR_FLAG(F_SF);
		SET_FLAG(F_PF);
		SET_FLAG(F_ZF);
	}
	return res;
}
/****************************************************************************
REMARKS:
Implements the SHRD instruction and side effects.
****************************************************************************/
static uint16_t
shrd_word(struct X86EMU *emu, uint16_t d, uint16_t fill, uint8_t s)
{
	unsigned int cnt, res, cf;

	if (s < 16) {
		cnt = s % 16;
		if (cnt > 0) {
			cf = d & (1 << (cnt - 1));
			res = (d >> cnt) | (fill << (16 - cnt));
			CONDITIONAL_SET_FLAG(cf, F_CF);
			CONDITIONAL_SET_FLAG((res & 0xffff) == 0, F_ZF);
			CONDITIONAL_SET_FLAG(res & 0x8000, F_SF);
			CONDITIONAL_SET_FLAG(PARITY(res & 0xff), F_PF);
		} else {
			res = d;
		}

		if (cnt == 1) {
			CONDITIONAL_SET_FLAG(XOR2(res >> 14), F_OF);
		} else {
			CLEAR_FLAG(F_OF);
		}
	} else {
		res = 0;
		CLEAR_FLAG(F_CF);
		CLEAR_FLAG(F_OF);
		SET_FLAG(F_ZF);
		CLEAR_FLAG(F_SF);
		CLEAR_FLAG(F_PF);
	}
	return (uint16_t) res;
}
/****************************************************************************
REMARKS:
Implements the SHRD instruction and side effects.
****************************************************************************/
static uint32_t
shrd_long(struct X86EMU *emu, uint32_t d, uint32_t fill, uint8_t s)
{
	unsigned int cnt, res, cf;

	if (s < 32) {
		cnt = s % 32;
		if (cnt > 0) {
			cf = d & (1 << (cnt - 1));
			res = (d >> cnt) | (fill << (32 - cnt));
			CONDITIONAL_SET_FLAG(cf, F_CF);
			CONDITIONAL_SET_FLAG((res & 0xffffffff) == 0, F_ZF);
			CONDITIONAL_SET_FLAG(res & 0x80000000, F_SF);
			CONDITIONAL_SET_FLAG(PARITY(res & 0xff), F_PF);
		} else {
			res = d;
		}
		if (cnt == 1) {
			CONDITIONAL_SET_FLAG(XOR2(res >> 30), F_OF);
		} else {
			CLEAR_FLAG(F_OF);
		}
	} else {
		res = 0;
		CLEAR_FLAG(F_CF);
		CLEAR_FLAG(F_OF);
		SET_FLAG(F_ZF);
		CLEAR_FLAG(F_SF);
		CLEAR_FLAG(F_PF);
	}
	return res;
}
/****************************************************************************
REMARKS:
Implements the SBB instruction and side effects.
****************************************************************************/
static uint8_t
sbb_byte(struct X86EMU *emu, uint8_t d, uint8_t s)
{
	uint32_t res;	/* all operands in native machine order */
	uint32_t bc;

	if (ACCESS_FLAG(F_CF))
		res = d - s - 1;
	else
		res = d - s;
	CONDITIONAL_SET_FLAG(res & 0x80, F_SF);
	CONDITIONAL_SET_FLAG((res & 0xff) == 0, F_ZF);
	CONDITIONAL_SET_FLAG(PARITY(res & 0xff), F_PF);

	/* calculate the borrow chain.  See note at top */
	bc = (res & (~d | s)) | (~d & s);
	CONDITIONAL_SET_FLAG(bc & 0x80, F_CF);
	CONDITIONAL_SET_FLAG(XOR2(bc >> 6), F_OF);
	CONDITIONAL_SET_FLAG(bc & 0x8, F_AF);
	return (uint8_t) res;
}
/****************************************************************************
REMARKS:
Implements the SBB instruction and side effects.
****************************************************************************/
static uint16_t
sbb_word(struct X86EMU *emu, uint16_t d, uint16_t s)
{
	uint32_t res;	/* all operands in native machine order */
	uint32_t bc;

	if (ACCESS_FLAG(F_CF))
		res = d - s - 1;
	else
		res = d - s;
	CONDITIONAL_SET_FLAG(res & 0x8000, F_SF);
	CONDITIONAL_SET_FLAG((res & 0xffff) == 0, F_ZF);
	CONDITIONAL_SET_FLAG(PARITY(res & 0xff), F_PF);

	/* calculate the borrow chain.  See note at top */
	bc = (res & (~d | s)) | (~d & s);
	CONDITIONAL_SET_FLAG(bc & 0x8000, F_CF);
	CONDITIONAL_SET_FLAG(XOR2(bc >> 14), F_OF);
	CONDITIONAL_SET_FLAG(bc & 0x8, F_AF);
	return (uint16_t) res;
}
/****************************************************************************
REMARKS:
Implements the SBB instruction and side effects.
****************************************************************************/
static uint32_t
sbb_long(struct X86EMU *emu, uint32_t d, uint32_t s)
{
	uint32_t res;	/* all operands in native machine order */
	uint32_t bc;

	if (ACCESS_FLAG(F_CF))
		res = d - s - 1;
	else
		res = d - s;
	CONDITIONAL_SET_FLAG(res & 0x80000000, F_SF);
	CONDITIONAL_SET_FLAG((res & 0xffffffff) == 0, F_ZF);
	CONDITIONAL_SET_FLAG(PARITY(res & 0xff), F_PF);

	/* calculate the borrow chain.  See note at top */
	bc = (res & (~d | s)) | (~d & s);
	CONDITIONAL_SET_FLAG(bc & 0x80000000, F_CF);
	CONDITIONAL_SET_FLAG(XOR2(bc >> 30), F_OF);
	CONDITIONAL_SET_FLAG(bc & 0x8, F_AF);
	return res;
}
/****************************************************************************
REMARKS:
Implements the SUB instruction and side effects.
****************************************************************************/
static uint8_t
sub_byte(struct X86EMU *emu, uint8_t d, uint8_t s)
{
	uint32_t res;	/* all operands in native machine order */
	uint32_t bc;

	res = d - s;
	CONDITIONAL_SET_FLAG(res & 0x80, F_SF);
	CONDITIONAL_SET_FLAG((res & 0xff) == 0, F_ZF);
	CONDITIONAL_SET_FLAG(PARITY(res & 0xff), F_PF);

	/* calculate the borrow chain.  See note at top */
	bc = (res & (~d | s)) | (~d & s);
	CONDITIONAL_SET_FLAG(bc & 0x80, F_CF);
	CONDITIONAL_SET_FLAG(XOR2(bc >> 6), F_OF);
	CONDITIONAL_SET_FLAG(bc & 0x8, F_AF);
	return (uint8_t) res;
}
/****************************************************************************
REMARKS:
Implements the SUB instruction and side effects.
****************************************************************************/
static uint16_t
sub_word(struct X86EMU *emu, uint16_t d, uint16_t s)
{
	uint32_t res;	/* all operands in native machine order */
	uint32_t bc;

	res = d - s;
	CONDITIONAL_SET_FLAG(res & 0x8000, F_SF);
	CONDITIONAL_SET_FLAG((res & 0xffff) == 0, F_ZF);
	CONDITIONAL_SET_FLAG(PARITY(res & 0xff), F_PF);

	/* calculate the borrow chain.  See note at top */
	bc = (res & (~d | s)) | (~d & s);
	CONDITIONAL_SET_FLAG(bc & 0x8000, F_CF);
	CONDITIONAL_SET_FLAG(XOR2(bc >> 14), F_OF);
	CONDITIONAL_SET_FLAG(bc & 0x8, F_AF);
	return (uint16_t) res;
}
/****************************************************************************
REMARKS:
Implements the SUB instruction and side effects.
****************************************************************************/
static uint32_t
sub_long(struct X86EMU *emu, uint32_t d, uint32_t s)
{
	uint32_t res;	/* all operands in native machine order */
	uint32_t bc;

	res = d - s;
	CONDITIONAL_SET_FLAG(res & 0x80000000, F_SF);
	CONDITIONAL_SET_FLAG((res & 0xffffffff) == 0, F_ZF);
	CONDITIONAL_SET_FLAG(PARITY(res & 0xff), F_PF);

	/* calculate the borrow chain.  See note at top */
	bc = (res & (~d | s)) | (~d & s);
	CONDITIONAL_SET_FLAG(bc & 0x80000000, F_CF);
	CONDITIONAL_SET_FLAG(XOR2(bc >> 30), F_OF);
	CONDITIONAL_SET_FLAG(bc & 0x8, F_AF);
	return res;
}
/****************************************************************************
REMARKS:
Implements the TEST instruction and side effects.
****************************************************************************/
static void
test_byte(struct X86EMU *emu, uint8_t d, uint8_t s)
{
	uint32_t res;	/* all operands in native machine order */

	res = d & s;

	CLEAR_FLAG(F_OF);
	CONDITIONAL_SET_FLAG(res & 0x80, F_SF);
	CONDITIONAL_SET_FLAG(res == 0, F_ZF);
	CONDITIONAL_SET_FLAG(PARITY(res & 0xff), F_PF);
	/* AF == dont care */
	CLEAR_FLAG(F_CF);
}
/****************************************************************************
REMARKS:
Implements the TEST instruction and side effects.
****************************************************************************/
static void
test_word(struct X86EMU *emu, uint16_t d, uint16_t s)
{
	uint32_t res;	/* all operands in native machine order */

	res = d & s;

	CLEAR_FLAG(F_OF);
	CONDITIONAL_SET_FLAG(res & 0x8000, F_SF);
	CONDITIONAL_SET_FLAG(res == 0, F_ZF);
	CONDITIONAL_SET_FLAG(PARITY(res & 0xff), F_PF);
	/* AF == dont care */
	CLEAR_FLAG(F_CF);
}
/****************************************************************************
REMARKS:
Implements the TEST instruction and side effects.
****************************************************************************/
static void
test_long(struct X86EMU *emu, uint32_t d, uint32_t s)
{
	uint32_t res;	/* all operands in native machine order */

	res = d & s;

	CLEAR_FLAG(F_OF);
	CONDITIONAL_SET_FLAG(res & 0x80000000, F_SF);
	CONDITIONAL_SET_FLAG(res == 0, F_ZF);
	CONDITIONAL_SET_FLAG(PARITY(res & 0xff), F_PF);
	/* AF == dont care */
	CLEAR_FLAG(F_CF);
}
/****************************************************************************
REMARKS:
Implements the XOR instruction and side effects.
****************************************************************************/
static uint8_t
xor_byte(struct X86EMU *emu, uint8_t d, uint8_t s)
{
	uint8_t res;	/* all operands in native machine order */

	res = d ^ s;
	CLEAR_FLAG(F_OF);
	CONDITIONAL_SET_FLAG(res & 0x80, F_SF);
	CONDITIONAL_SET_FLAG(res == 0, F_ZF);
	CONDITIONAL_SET_FLAG(PARITY(res), F_PF);
	CLEAR_FLAG(F_CF);
	CLEAR_FLAG(F_AF);
	return res;
}
/****************************************************************************
REMARKS:
Implements the XOR instruction and side effects.
****************************************************************************/
static uint16_t
xor_word(struct X86EMU *emu, uint16_t d, uint16_t s)
{
	uint16_t res;	/* all operands in native machine order */

	res = d ^ s;
	CLEAR_FLAG(F_OF);
	CONDITIONAL_SET_FLAG(res & 0x8000, F_SF);
	CONDITIONAL_SET_FLAG(res == 0, F_ZF);
	CONDITIONAL_SET_FLAG(PARITY(res & 0xff), F_PF);
	CLEAR_FLAG(F_CF);
	CLEAR_FLAG(F_AF);
	return res;
}
/****************************************************************************
REMARKS:
Implements the XOR instruction and side effects.
****************************************************************************/
static uint32_t
xor_long(struct X86EMU *emu, uint32_t d, uint32_t s)
{
	uint32_t res;	/* all operands in native machine order */

	res = d ^ s;
	CLEAR_FLAG(F_OF);
	CONDITIONAL_SET_FLAG(res & 0x80000000, F_SF);
	CONDITIONAL_SET_FLAG(res == 0, F_ZF);
	CONDITIONAL_SET_FLAG(PARITY(res & 0xff), F_PF);
	CLEAR_FLAG(F_CF);
	CLEAR_FLAG(F_AF);
	return res;
}
/****************************************************************************
REMARKS:
Implements the IMUL instruction and side effects.
****************************************************************************/
static void
imul_byte(struct X86EMU *emu, uint8_t s)
{
	int16_t res = (int16_t) ((int8_t) emu->x86.R_AL * (int8_t) s);

	emu->x86.R_AX = res;
	if (((emu->x86.R_AL & 0x80) == 0 && emu->x86.R_AH == 0x00) ||
	    ((emu->x86.R_AL & 0x80) != 0 && emu->x86.R_AH == 0xFF)) {
		CLEAR_FLAG(F_CF);
		CLEAR_FLAG(F_OF);
	} else {
		SET_FLAG(F_CF);
		SET_FLAG(F_OF);
	}
}
/****************************************************************************
REMARKS:
Implements the IMUL instruction and side effects.
****************************************************************************/
static void
imul_word(struct X86EMU *emu, uint16_t s)
{
	int32_t res = (int16_t) emu->x86.R_AX * (int16_t) s;

	emu->x86.R_AX = (uint16_t) res;
	emu->x86.R_DX = (uint16_t) (res >> 16);
	if (((emu->x86.R_AX & 0x8000) == 0 && emu->x86.R_DX == 0x00) ||
	    ((emu->x86.R_AX & 0x8000) != 0 && emu->x86.R_DX == 0xFF)) {
		CLEAR_FLAG(F_CF);
		CLEAR_FLAG(F_OF);
	} else {
		SET_FLAG(F_CF);
		SET_FLAG(F_OF);
	}
}
/****************************************************************************
REMARKS:
Implements the IMUL instruction and side effects.
****************************************************************************/
static void
imul_long(struct X86EMU *emu, uint32_t s)
{
	int64_t res;

	res = (int64_t)(int32_t)emu->x86.R_EAX * (int32_t)s;
	emu->x86.R_EAX = (uint32_t)res;
	emu->x86.R_EDX = ((uint64_t)res) >> 32;
	if (((emu->x86.R_EAX & 0x80000000) == 0 && emu->x86.R_EDX == 0x00) ||
	    ((emu->x86.R_EAX & 0x80000000) != 0 && emu->x86.R_EDX == 0xFF)) {
		CLEAR_FLAG(F_CF);
		CLEAR_FLAG(F_OF);
	} else {
		SET_FLAG(F_CF);
		SET_FLAG(F_OF);
	}
}
/****************************************************************************
REMARKS:
Implements the MUL instruction and side effects.
****************************************************************************/
static void
mul_byte(struct X86EMU *emu, uint8_t s)
{
	uint16_t res = (uint16_t) (emu->x86.R_AL * s);

	emu->x86.R_AX = res;
	if (emu->x86.R_AH == 0) {
		CLEAR_FLAG(F_CF);
		CLEAR_FLAG(F_OF);
	} else {
		SET_FLAG(F_CF);
		SET_FLAG(F_OF);
	}
}
/****************************************************************************
REMARKS:
Implements the MUL instruction and side effects.
****************************************************************************/
static void
mul_word(struct X86EMU *emu, uint16_t s)
{
	uint32_t res = emu->x86.R_AX * s;

	emu->x86.R_AX = (uint16_t) res;
	emu->x86.R_DX = (uint16_t) (res >> 16);
	if (emu->x86.R_DX == 0) {
		CLEAR_FLAG(F_CF);
		CLEAR_FLAG(F_OF);
	} else {
		SET_FLAG(F_CF);
		SET_FLAG(F_OF);
	}
}
/****************************************************************************
REMARKS:
Implements the MUL instruction and side effects.
****************************************************************************/
static void
mul_long(struct X86EMU *emu, uint32_t s)
{
	uint64_t res = (uint64_t) emu->x86.R_EAX * s;

	emu->x86.R_EAX = (uint32_t) res;
	emu->x86.R_EDX = (uint32_t) (res >> 32);

	if (emu->x86.R_EDX == 0) {
		CLEAR_FLAG(F_CF);
		CLEAR_FLAG(F_OF);
	} else {
		SET_FLAG(F_CF);
		SET_FLAG(F_OF);
	}
}
/****************************************************************************
REMARKS:
Implements the IDIV instruction and side effects.
****************************************************************************/
static void
idiv_byte(struct X86EMU *emu, uint8_t s)
{
	int32_t dvd, div, mod;

	dvd = (int16_t) emu->x86.R_AX;
	if (s == 0) {
		x86emu_intr_raise(emu, 8);
		return;
	}
	div = dvd / (int8_t) s;
	mod = dvd % (int8_t) s;
	if (div > 0x7f || div < -0x7f) {
		x86emu_intr_raise(emu, 8);
		return;
	}
	emu->x86.R_AL = (int8_t) div;
	emu->x86.R_AH = (int8_t) mod;
}
/****************************************************************************
REMARKS:
Implements the IDIV instruction and side effects.
****************************************************************************/
static void
idiv_word(struct X86EMU *emu, uint16_t s)
{
	int32_t dvd, div, mod;

	dvd = (((int32_t) emu->x86.R_DX) << 16) | emu->x86.R_AX;
	if (s == 0) {
		x86emu_intr_raise(emu, 8);
		return;
	}
	div = dvd / (int16_t) s;
	mod = dvd % (int16_t) s;
	if (div > 0x7fff || div < -0x7fff) {
		x86emu_intr_raise(emu, 8);
		return;
	}
	CLEAR_FLAG(F_CF);
	CLEAR_FLAG(F_SF);
	CONDITIONAL_SET_FLAG(div == 0, F_ZF);
	CONDITIONAL_SET_FLAG(PARITY(mod & 0xff), F_PF);

	emu->x86.R_AX = (uint16_t) div;
	emu->x86.R_DX = (uint16_t) mod;
}
/****************************************************************************
REMARKS:
Implements the IDIV instruction and side effects.
****************************************************************************/
static void
idiv_long(struct X86EMU *emu, uint32_t s)
{
	int64_t dvd, div, mod;

	dvd = (((int64_t) emu->x86.R_EDX) << 32) | emu->x86.R_EAX;
	if (s == 0) {
		x86emu_intr_raise(emu, 8);
		return;
	}
	div = dvd / (int32_t) s;
	mod = dvd % (int32_t) s;
	if (div > 0x7fffffff || div < -0x7fffffff) {
		x86emu_intr_raise(emu, 8);
		return;
	}
	CLEAR_FLAG(F_CF);
	CLEAR_FLAG(F_AF);
	CLEAR_FLAG(F_SF);
	SET_FLAG(F_ZF);
	CONDITIONAL_SET_FLAG(PARITY(mod & 0xff), F_PF);

	emu->x86.R_EAX = (uint32_t) div;
	emu->x86.R_EDX = (uint32_t) mod;
}
/****************************************************************************
REMARKS:
Implements the DIV instruction and side effects.
****************************************************************************/
static void
div_byte(struct X86EMU *emu, uint8_t s)
{
	uint32_t dvd, div, mod;

	dvd = emu->x86.R_AX;
	if (s == 0) {
		x86emu_intr_raise(emu, 8);
		return;
	}
	div = dvd / (uint8_t) s;
	mod = dvd % (uint8_t) s;
	if (div > 0xff) {
		x86emu_intr_raise(emu, 8);
		return;
	}
	emu->x86.R_AL = (uint8_t) div;
	emu->x86.R_AH = (uint8_t) mod;
}
/****************************************************************************
REMARKS:
Implements the DIV instruction and side effects.
****************************************************************************/
static void
div_word(struct X86EMU *emu, uint16_t s)
{
	uint32_t dvd, div, mod;

	dvd = (((uint32_t) emu->x86.R_DX) << 16) | emu->x86.R_AX;
	if (s == 0) {
		x86emu_intr_raise(emu, 8);
		return;
	}
	div = dvd / (uint16_t) s;
	mod = dvd % (uint16_t) s;
	if (div > 0xffff) {
		x86emu_intr_raise(emu, 8);
		return;
	}
	CLEAR_FLAG(F_CF);
	CLEAR_FLAG(F_SF);
	CONDITIONAL_SET_FLAG(div == 0, F_ZF);
	CONDITIONAL_SET_FLAG(PARITY(mod & 0xff), F_PF);

	emu->x86.R_AX = (uint16_t) div;
	emu->x86.R_DX = (uint16_t) mod;
}
/****************************************************************************
REMARKS:
Implements the DIV instruction and side effects.
****************************************************************************/
static void
div_long(struct X86EMU *emu, uint32_t s)
{
	uint64_t dvd, div, mod;

	dvd = (((uint64_t) emu->x86.R_EDX) << 32) | emu->x86.R_EAX;
	if (s == 0) {
		x86emu_intr_raise(emu, 8);
		return;
	}
	div = dvd / (uint32_t) s;
	mod = dvd % (uint32_t) s;
	if (div > 0xffffffff) {
		x86emu_intr_raise(emu, 8);
		return;
	}
	CLEAR_FLAG(F_CF);
	CLEAR_FLAG(F_AF);
	CLEAR_FLAG(F_SF);
	SET_FLAG(F_ZF);
	CONDITIONAL_SET_FLAG(PARITY(mod & 0xff), F_PF);

	emu->x86.R_EAX = (uint32_t) div;
	emu->x86.R_EDX = (uint32_t) mod;
}
/****************************************************************************
REMARKS:
Implements the IN string instruction and side effects.
****************************************************************************/
static void
ins(struct X86EMU *emu, int size)
{
	int inc = size;

	if (ACCESS_FLAG(F_DF)) {
		inc = -size;
	}
	if (emu->x86.mode & (SYSMODE_PREFIX_REPE | SYSMODE_PREFIX_REPNE)) {
		/* dont care whether REPE or REPNE */
		/* in until CX is ZERO. */
		uint32_t count = ((emu->x86.mode & SYSMODE_PREFIX_DATA) ?
		    emu->x86.R_ECX : emu->x86.R_CX);
		switch (size) {
		case 1:
			while (count--) {
				store_byte(emu, emu->x86.R_ES, emu->x86.R_DI,
				    (*emu->emu_inb) (emu, emu->x86.R_DX));
				emu->x86.R_DI += inc;
			}
			break;

		case 2:
			while (count--) {
				store_word(emu, emu->x86.R_ES, emu->x86.R_DI,
				    (*emu->emu_inw) (emu, emu->x86.R_DX));
				emu->x86.R_DI += inc;
			}
			break;
		case 4:
			while (count--) {
				store_long(emu, emu->x86.R_ES, emu->x86.R_DI,
				    (*emu->emu_inl) (emu, emu->x86.R_DX));
				emu->x86.R_DI += inc;
				break;
			}
		}
		emu->x86.R_CX = 0;
		if (emu->x86.mode & SYSMODE_PREFIX_DATA) {
			emu->x86.R_ECX = 0;
		}
		emu->x86.mode &= ~(SYSMODE_PREFIX_REPE | SYSMODE_PREFIX_REPNE);
	} else {
		switch (size) {
		case 1:
			store_byte(emu, emu->x86.R_ES, emu->x86.R_DI,
			    (*emu->emu_inb) (emu, emu->x86.R_DX));
			break;
		case 2:
			store_word(emu, emu->x86.R_ES, emu->x86.R_DI,
			    (*emu->emu_inw) (emu, emu->x86.R_DX));
			break;
		case 4:
			store_long(emu, emu->x86.R_ES, emu->x86.R_DI,
			    (*emu->emu_inl) (emu, emu->x86.R_DX));
			break;
		}
		emu->x86.R_DI += inc;
	}
}
/****************************************************************************
REMARKS:
Implements the OUT string instruction and side effects.
****************************************************************************/
static void
outs(struct X86EMU *emu, int size)
{
	int inc = size;

	if (ACCESS_FLAG(F_DF)) {
		inc = -size;
	}
	if (emu->x86.mode & (SYSMODE_PREFIX_REPE | SYSMODE_PREFIX_REPNE)) {
		/* dont care whether REPE or REPNE */
		/* out until CX is ZERO. */
		uint32_t count = ((emu->x86.mode & SYSMODE_PREFIX_DATA) ?
		    emu->x86.R_ECX : emu->x86.R_CX);
		switch (size) {
		case 1:
			while (count--) {
				(*emu->emu_outb) (emu, emu->x86.R_DX,
				    fetch_byte(emu, emu->x86.R_ES, emu->x86.R_SI));
				emu->x86.R_SI += inc;
			}
			break;

		case 2:
			while (count--) {
				(*emu->emu_outw) (emu, emu->x86.R_DX,
				    fetch_word(emu, emu->x86.R_ES, emu->x86.R_SI));
				emu->x86.R_SI += inc;
			}
			break;
		case 4:
			while (count--) {
				(*emu->emu_outl) (emu, emu->x86.R_DX,
				    fetch_long(emu, emu->x86.R_ES, emu->x86.R_SI));
				emu->x86.R_SI += inc;
				break;
			}
		}
		emu->x86.R_CX = 0;
		if (emu->x86.mode & SYSMODE_PREFIX_DATA) {
			emu->x86.R_ECX = 0;
		}
		emu->x86.mode &= ~(SYSMODE_PREFIX_REPE | SYSMODE_PREFIX_REPNE);
	} else {
		switch (size) {
		case 1:
			(*emu->emu_outb) (emu, emu->x86.R_DX,
			    fetch_byte(emu, emu->x86.R_ES, emu->x86.R_SI));
			break;
		case 2:
			(*emu->emu_outw) (emu, emu->x86.R_DX,
			    fetch_word(emu, emu->x86.R_ES, emu->x86.R_SI));
			break;
		case 4:
			(*emu->emu_outl) (emu, emu->x86.R_DX,
			    fetch_long(emu, emu->x86.R_ES, emu->x86.R_SI));
			break;
		}
		emu->x86.R_SI += inc;
	}
}
/****************************************************************************
REMARKS:
Pushes a word onto the stack.

NOTE: Do not inline this, as (*emu->emu_wrX) is already inline!
****************************************************************************/
static void
push_word(struct X86EMU *emu, uint16_t w)
{
	emu->x86.R_SP -= 2;
	store_word(emu, emu->x86.R_SS, emu->x86.R_SP, w);
}
/****************************************************************************
REMARKS:
Pushes a long onto the stack.

NOTE: Do not inline this, as (*emu->emu_wrX) is already inline!
****************************************************************************/
static void
push_long(struct X86EMU *emu, uint32_t w)
{
	emu->x86.R_SP -= 4;
	store_long(emu, emu->x86.R_SS, emu->x86.R_SP, w);
}
/****************************************************************************
REMARKS:
Pops a word from the stack.

NOTE: Do not inline this, as (*emu->emu_rdX) is already inline!
****************************************************************************/
static uint16_t
pop_word(struct X86EMU *emu)
{
	uint16_t res;

	res = fetch_word(emu, emu->x86.R_SS, emu->x86.R_SP);
	emu->x86.R_SP += 2;
	return res;
}
/****************************************************************************
REMARKS:
Pops a long from the stack.

NOTE: Do not inline this, as (*emu->emu_rdX) is already inline!
****************************************************************************/
static uint32_t
pop_long(struct X86EMU *emu)
{
	uint32_t res;

	res = fetch_long(emu, emu->x86.R_SS, emu->x86.R_SP);
	emu->x86.R_SP += 4;
	return res;
}