xref: /src/sys/arch/hppa/spmath/cnv_float.h

/*	$NetBSD: cnv_float.h,v 1.4 2019/02/06 05:04:41 mrg Exp $	*/

/*	$OpenBSD: cnv_float.h,v 1.5 2001/03/29 03:58:17 mickey Exp $	*/

/*
 * Copyright 1996 1995 by Open Software Foundation, Inc.
 *              All Rights Reserved
 *
 * Permission to use, copy, modify, and distribute this software and
 * its documentation for any purpose and without fee is hereby granted,
 * provided that the above copyright notice appears in all copies and
 * that both the copyright notice and this permission notice appear in
 * supporting documentation.
 *
 * OSF DISCLAIMS ALL WARRANTIES WITH REGARD TO THIS SOFTWARE
 * INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
 * FOR A PARTICULAR PURPOSE.
 *
 * IN NO EVENT SHALL OSF BE LIABLE FOR ANY SPECIAL, INDIRECT, OR
 * CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM
 * LOSS OF USE, DATA OR PROFITS, WHETHER IN ACTION OF CONTRACT,
 * NEGLIGENCE, OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION
 * WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
 */
/*
 * pmk1.1
 */
/*
 * (c) Copyright 1986 HEWLETT-PACKARD COMPANY
 *
 * To anyone who acknowledges that this file is provided "AS IS"
 * without any express or implied warranty:
 *     permission to use, copy, modify, and distribute this file
 * for any purpose is hereby granted without fee, provided that
 * the above copyright notice and this notice appears in all
 * copies, and that the name of Hewlett-Packard Company not be
 * used in advertising or publicity pertaining to distribution
 * of the software without specific, written prior permission.
 * Hewlett-Packard Company makes no representations about the
 * suitability of this software for any purpose.
 */

/*
 * Some more constants
 */
#define SGL_FX_MAX_EXP 30
#define DBL_FX_MAX_EXP 62
#define QUAD_FX_MAX_EXP 126


#define Dintp1(object) (object)
#define Dintp2(object) (object)

#define Qintp0(object) (object)
#define Qintp1(object) (object)
#define Qintp2(object) (object)
#define Qintp3(object) (object)


/*
 * These macros will be used specifically by the convert instructions.
 *
 *
 * Single format macros
 */

#define Sgl_to_dbl_exponent(src_exponent,dest)			\
    Deposit_dexponent(dest,src_exponent+(DBL_BIAS-SGL_BIAS))

#define Sgl_to_dbl_mantissa(src_mantissa,destA,destB)	\
    Deposit_dmantissap1(destA,src_mantissa>>3);		\
    Dmantissap2(destB) = src_mantissa << 29

#define Sgl_isinexact_to_fix(sgl_value,exponent)	\
    ((exponent < (SGL_P - 1)) ?				\
     (Sall(sgl_value) << (SGL_EXP_LENGTH + 1 + exponent)) : false)

#define Int_isinexact_to_sgl(int_value)	((int_value << (33 - SGL_EXP_LENGTH)) != 0)

#define Sgl_roundnearest_from_int(int_value,sgl_value)			\
    if (int_value & 1<<(SGL_EXP_LENGTH - 2))   /* round bit */		\
	if (((int_value << (34 - SGL_EXP_LENGTH)) != 0) || Slow(sgl_value))	\
		Sall(sgl_value)++

#define Dint_isinexact_to_sgl(dint_valueA,dint_valueB)		\
    (((Dintp1(dint_valueA) << (33 - SGL_EXP_LENGTH)) != 0) || Dintp2(dint_valueB))

#define Sgl_roundnearest_from_dint(dint_valueA,dint_valueB,sgl_value)	\
    if (Dintp1(dint_valueA) & 1<<(SGL_EXP_LENGTH - 2))			\
	if (((Dintp1(dint_valueA) << (34 - SGL_EXP_LENGTH)) != 0) ||	\
	Dintp2(dint_valueB) || Slow(sgl_value)) Sall(sgl_value)++

#define Dint_isinexact_to_dbl(dint_value)	\
    (Dintp2(dint_value) << (33 - DBL_EXP_LENGTH))

#define Dbl_roundnearest_from_dint(dint_opndB,dbl_opndA,dbl_opndB)	\
    if (Dintp2(dint_opndB) & 1<<(DBL_EXP_LENGTH - 2))			\
       if ((Dintp2(dint_opndB) << (34 -DBL_EXP_LENGTH)) || Dlowp2(dbl_opndB))  \
	  if ((++Dallp2(dbl_opndB))==0) Dallp1(dbl_opndA)++

#define Sgl_isone_roundbit(sgl_value,exponent)			\
    ((Sall(sgl_value) << (SGL_EXP_LENGTH + 1 + exponent)) >> 31)

#define Sgl_isone_stickybit(sgl_value,exponent)		\
    (exponent < (SGL_P - 2) ?				\
     Sall(sgl_value) << (SGL_EXP_LENGTH + 2 + exponent) : false)


/*
 * Double format macros
 */

#define Dbl_to_sgl_exponent(src_exponent,dest)			\
    dest = src_exponent + (SGL_BIAS - DBL_BIAS)

#define Dbl_to_sgl_mantissa(srcA,srcB,dest,inexact,guard,sticky,odd)	\
    Shiftdouble(Dmantissap1(srcA),Dmantissap2(srcB),29,dest);	\
    guard = Dbit3p2(srcB);					\
    sticky = Dallp2(srcB)<<4;					\
    inexact = guard | sticky;					\
    odd = Dbit2p2(srcB)

#define Dbl_to_sgl_denormalized(srcA,srcB,exp,dest,inexact,guard,sticky,odd,tiny) \
    Deposit_dexponent(srcA,1);						\
    tiny = true;							\
    if (exp >= -2) {							\
	if (exp == 0) {							\
	    inexact = Dallp2(srcB) << 3;				\
	    guard = inexact >> 31;					\
	    sticky = inexact << 1;					\
	    Shiftdouble(Dmantissap1(srcA),Dmantissap2(srcB),29,dest);	\
	    odd = dest << 31;						\
	    if (inexact) {						\
		switch(Rounding_mode()) {				\
		    case ROUNDPLUS:					\
			if (Dbl_iszero_sign(srcA)) {			\
			    dest++;					\
			    if (Sgl_isone_hidden(dest))	\
				tiny = false;				\
			    dest--;					\
			}						\
			break;						\
		    case ROUNDMINUS:					\
			if (Dbl_isone_sign(srcA)) {			\
			    dest++;					\
			    if (Sgl_isone_hidden(dest))	\
				tiny = false;				\
			    dest--;					\
			}						\
			break;						\
		    case ROUNDNEAREST:					\
			if (guard && (sticky || odd)) {			\
			    dest++;					\
			    if (Sgl_isone_hidden(dest))	\
				tiny = false;				\
			    dest--;					\
			}						\
			break;						\
		}							\
	    }								\
		/* shift right by one to get correct result */		\
		guard = odd;						\
		sticky = inexact;					\
		inexact |= guard;					\
		dest >>= 1;						\
		Deposit_dsign(srcA,0);					\
		Shiftdouble(Dallp1(srcA),Dallp2(srcB),30,dest);		\
		odd = dest << 31;					\
	}								\
	else {								\
	    inexact = Dallp2(srcB) << (2 + exp);			\
	    guard = inexact >> 31;					\
	    sticky = inexact << 1;					\
	    Deposit_dsign(srcA,0);					\
	    if (exp == -2) dest = Dallp1(srcA);				\
	    else Variable_shift_double(Dallp1(srcA),Dallp2(srcB),30-exp,dest); \
	    odd = dest << 31;						\
	}								\
    }									\
    else {								\
	Deposit_dsign(srcA,0);						\
	if (exp > (1 - SGL_P)) {					\
	    dest = Dallp1(srcA) >> (- 2 - exp);				\
	    inexact = Dallp1(srcA) << (34 + exp);			\
	    guard = inexact >> 31;					\
	    sticky = (inexact << 1) | Dallp2(srcB);			\
	    inexact |= Dallp2(srcB);					\
	    odd = dest << 31;						\
	}								\
	else {								\
	    dest = 0;							\
	    inexact = Dallp1(srcA) | Dallp2(srcB);			\
	    if (exp == (1 - SGL_P)) {					\
		guard = Dhidden(srcA);					\
		sticky = Dmantissap1(srcA) | Dallp2(srcB);		\
	    }								\
	    else {							\
		guard = 0;						\
		sticky = inexact;					\
	    }								\
	    odd = 0;							\
	}								\
    }									\
    exp = 0

#define Dbl_isinexact_to_fix(dbl_valueA,dbl_valueB,exponent)		\
    (exponent < (DBL_P-33) ?						\
     Dallp2(dbl_valueB) || Dallp1(dbl_valueA) << (DBL_EXP_LENGTH+1+exponent) : \
     (exponent < (DBL_P-1) ? Dallp2(dbl_valueB) << (exponent + (33-DBL_P)) :   \
      false))

#define Dbl_isoverflow_to_int(exponent,dbl_valueA,dbl_valueB)		\
    ((exponent > SGL_FX_MAX_EXP + 1) || Dsign(dbl_valueA)==0 ||		\
     Dmantissap1(dbl_valueA)!=0 || (Dallp2(dbl_valueB)>>21)!=0 )

#define Dbl_isone_roundbit(dbl_valueA,dbl_valueB,exponent)	      \
    ((exponent < (DBL_P - 33) ?						\
      Dallp1(dbl_valueA) >> ((30 - DBL_EXP_LENGTH) - exponent) :	\
      Dallp2(dbl_valueB) >> ((DBL_P - 2) - exponent)) & 1)

#define Dbl_isone_stickybit(dbl_valueA,dbl_valueB,exponent)		\
    (exponent < (DBL_P-34) ?						\
     (Dallp2(dbl_valueB) || Dallp1(dbl_valueA)<<(DBL_EXP_LENGTH+2+exponent)) : \
     (exponent<(DBL_P-2) ? (Dallp2(dbl_valueB) << (exponent + (34-DBL_P))) : \
      false))


/* Int macros */

#define Int_from_sgl_mantissa(sgl_value,exponent)	\
    Sall(sgl_value) =				\
	(unsigned)(Sall(sgl_value) << SGL_EXP_LENGTH)>>(31 - exponent)

#define Int_from_dbl_mantissa(dbl_valueA,dbl_valueB,exponent)	\
    Shiftdouble(Dallp1(dbl_valueA),Dallp2(dbl_valueB),22,Dallp1(dbl_valueA)); \
    if (exponent < 31) Dallp1(dbl_valueA) >>= 30 - exponent;	\
    else Dallp1(dbl_valueA) <<= 1

#define Int_negate(int_value) int_value = -int_value


/* Dint macros */

#define Dint_from_sgl_mantissa(sgl_value,exponent,dresultA,dresultB)	\
    {Sall(sgl_value) <<= SGL_EXP_LENGTH;  /*  left-justify  */		\
    if (exponent <= 31) {						\
	Dintp1(dresultA) = 0;						\
	Dintp2(dresultB) = (unsigned)Sall(sgl_value) >> (31 - exponent); \
    }									\
    else {								\
	Dintp1(dresultA) = Sall(sgl_value) >> (63 - exponent);		\
	Dintp2(dresultB) = Sall(sgl_value) << (exponent - 31);		\
    }}


#define Dint_from_dbl_mantissa(dbl_valueA,dbl_valueB,exponent,destA,destB) \
    {if (exponent < 32) {						\
	Dintp1(destA) = 0;						\
	if (exponent <= 20)						\
	    Dintp2(destB) = Dallp1(dbl_valueA) >> (20-(exponent));	\
	else Variable_shift_double(Dallp1(dbl_valueA),Dallp2(dbl_valueB), \
	     (52-(exponent)),Dintp2(destB));				\
    }									\
    else {								\
	if (exponent <= 52) {						\
	    Dintp1(destA) = Dallp1(dbl_valueA) >> (52-(exponent));	\
	    if (exponent == 52) Dintp2(destB) = Dallp2(dbl_valueB);	\
	    else Variable_shift_double(Dallp1(dbl_valueA),Dallp2(dbl_valueB), \
	    52-exponent,Dintp2(destB));					\
	}								\
	else {								\
	    Variable_shift_double(Dallp1(dbl_valueA),Dallp2(dbl_valueB), \
	    84-exponent,Dintp1(destA));					\
	    Dintp2(destB) = Dallp2(dbl_valueB) << ((exponent)-52);	\
	}								\
    }}

#define Dint_setzero(dresultA,dresultB)	\
    Dintp1(dresultA) = 0;	\
    Dintp2(dresultB) = 0

#define Dint_setone_sign(dresultA,dresultB)		\
    Dintp1(dresultA) = ~Dintp1(dresultA);		\
    if ((Dintp2(dresultB) = -Dintp2(dresultB)) == 0) Dintp1(dresultA)++

#define Dint_set_minint(dresultA,dresultB)		\
    Dintp1(dresultA) = 1<<31;				\
    Dintp2(dresultB) = 0

#define Dint_isone_lowp2(dresultB)  (Dintp2(dresultB) & 01)

#define Dint_increment(dresultA,dresultB)		\
    if ((++Dintp2(dresultB))==0) Dintp1(dresultA)++

#define Dint_decrement(dresultA,dresultB)		\
    if ((Dintp2(dresultB)--)==0) Dintp1(dresultA)--

#define Dint_negate(dresultA,dresultB)			\
    Dintp1(dresultA) = ~Dintp1(dresultA);		\
    if ((Dintp2(dresultB) = -Dintp2(dresultB))==0) Dintp1(dresultA)++

#define Dint_copyfromptr(src,destA,destB) \
     Dintp1(destA) = src->wd0;		\
     Dintp2(destB) = src->wd1
#define Dint_copytoptr(srcA,srcB,dest)	\
    dest->wd0 = Dintp1(srcA);		\
    dest->wd1 = Dintp2(srcB)


/* other macros  */

#define Find_ms_one_bit(value, position)	\
    {						\
	int var;				\
	for (var=8; var >=1; var >>= 1) {	\
	    if (value >> (32 - position))	\
		position -= var;		\
		else position += var;		\
	}					\
	if ((value >> (32 - position)) == 0)	\
	    position--;				\
	else position -= 2;			\
    }

/*
 * The following 4 functions handle the assignment of a floating point
 * number to a 32-bit integer in cases where the floating point number
 * is too large (or small) to fit in the integer field.
 *
 * In all these cases, HP-UX would return an UNIMPLEMENTEDEXCEPTION
 * resulting in a SIGFPE being sent to the process.  For BSD's math
 * library (and various other applications), this was unacceptable.
 * As a result, we now return maxint/minint (like most other OS's)
 * and either return an INEXACTEXCEPTION (SIGFPE) or set the inexact
 * flag (so that the program may continue execution).
 *
 * After discussing this with Jerry Huck @ HP, the one case where we
 * differ from BSD is for programs that try to convert a NaN to an
 * integer; in this case, we will return an UNIMPLEMENTEDEXCEPTION
 * since doing anything else would be completely unreasonable.
 *
 *	jef
 */

#define	Dbl_return_overflow(srcp1, srcp2, resultp)	\
    {						\
	if (Dbl_isnan(srcp1, srcp2))		\
		return(UNIMPLEMENTEDEXCEPTION);	\
	if (Dbl_iszero_sign(srcp1))		\
		*resultp = 0x7fffffff;		\
	else					\
		*resultp = 0x80000000;		\
	if (Is_overflowtrap_enabled()) {	\
		if (Is_inexacttrap_enabled())	\
			return(OVERFLOWEXCEPTION|INEXACTEXCEPTION);	\
		else				\
			Set_inexactflag();	\
		return(OVERFLOWEXCEPTION);	\
	}					\
	return(NOEXCEPTION);			\
    }

#define	Dbl_return_overflow_dbl(srcp1, srcp2, resultp)	\
    {						\
	if (Dbl_isnan(srcp1, srcp2))		\
		return(UNIMPLEMENTEDEXCEPTION);	\
	if (Dbl_iszero_sign(srcp1)) {		\
		Dint_copytoptr(0x7fffffff,0xffffffff,resultp); \
	} else {				\
		Dint_copytoptr(0x80000000,0x00000000,resultp); \
	}					\
	if (Is_overflowtrap_enabled()) {	\
		if (Is_inexacttrap_enabled())	\
			return(OVERFLOWEXCEPTION|INEXACTEXCEPTION);	\
		else				\
			Set_inexactflag();	\
		return(OVERFLOWEXCEPTION);	\
	}					\
	return(NOEXCEPTION);			\
    }

#define	Sgl_return_overflow(src, resultp)	\
    {						\
	if (Sgl_isnan(src))			\
		return(UNIMPLEMENTEDEXCEPTION);	\
	if (Sgl_iszero_sign(src))		\
		*resultp = 0x7fffffff;		\
	else					\
		*resultp = 0x80000000;		\
	if (Is_overflowtrap_enabled()) {	\
		if (Is_inexacttrap_enabled())	\
			return(OVERFLOWEXCEPTION|INEXACTEXCEPTION);	\
		else				\
			Set_inexactflag();	\
		return(OVERFLOWEXCEPTION);	\
	}					\
	return(NOEXCEPTION);			\
    }

#define	Sgl_return_overflow_dbl(src, resultp)	\
    {						\
	if (Sgl_isnan(src))			\
		return(UNIMPLEMENTEDEXCEPTION);	\
	if (Sgl_iszero_sign(src)) {		\
		Dint_copytoptr(0x7fffffff,0xffffffff,resultp); \
	} else {				\
		Dint_copytoptr(0x80000000,0x00000000,resultp); \
	}					\
	if (Is_overflowtrap_enabled()) {	\
		if (Is_inexacttrap_enabled())	\
			return(OVERFLOWEXCEPTION|INEXACTEXCEPTION);	\
		else				\
			Set_inexactflag();	\
		return(OVERFLOWEXCEPTION);	\
	}					\
	return(NOEXCEPTION);			\
    }

int sgl_to_sgl_fcnvfx(sgl_floating_point *, sgl_floating_point *, unsigned int *);
int sgl_to_dbl_fcnvfx(sgl_floating_point *, dbl_integer *, unsigned int *);
int dbl_to_sgl_fcnvfx(dbl_floating_point *, int *, unsigned int *);
int dbl_to_dbl_fcnvfx(dbl_floating_point *, dbl_integer *, unsigned int *);

int sgl_to_sgl_fcnvfxt(sgl_floating_point *, int *, unsigned int *);
int sgl_to_dbl_fcnvfxt(sgl_floating_point *, dbl_integer *, unsigned int *);
int dbl_to_sgl_fcnvfxt(dbl_floating_point *, int *, unsigned int *);
int dbl_to_dbl_fcnvfxt(dbl_floating_point *, dbl_integer *, unsigned int *);

int sgl_to_sgl_fcnvxf(int *, sgl_floating_point *, unsigned int *);
int sgl_to_dbl_fcnvxf(int *, dbl_floating_point *, unsigned int *);
int dbl_to_sgl_fcnvxf(dbl_integer *, sgl_floating_point *, unsigned int *);
int dbl_to_dbl_fcnvxf(dbl_integer *, dbl_floating_point *, unsigned int *);