xref: /src/sys/arch/m68k/fpe/fpu_fstore.c

/*	$NetBSD: fpu_fstore.c,v 1.14.72.1 2025/08/02 05:55:48 perseant Exp $	*/

/*
 * Copyright (c) 1995 Ken Nakata
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */

#include <sys/cdefs.h>
__KERNEL_RCSID(0, "$NetBSD: fpu_fstore.c,v 1.14.72.1 2025/08/02 05:55:48 perseant Exp $");

#include <sys/types.h>
#include <sys/signal.h>
#include <sys/systm.h>
#include <machine/frame.h>

#include "fpu_emulate.h"

/*
 * type 0: fmove mem/fpr->fpr
 * In this function, we know
 *	(opcode & 0x01c0) == 0
 *	(word1 & 0xe000) == 0x6000
 */
int
fpu_emul_fstore(struct fpemu *fe, struct instruction *insn)
{
	struct frame *frame = fe->fe_frame;
	uint32_t *fpregs = fe->fe_fpframe->fpf_regs;
	int word1, sig;
	int regnum;
	int format;
	int modreg;
	uint32_t buf[3];

#if DEBUG_FPE
	printf("  fpu_emul_fstore: frame at %p fpframe at %p\n",
	    frame, fe->fe_fpframe);
#endif

	word1 = insn->is_word1;
	format = (word1 >> 10) & 7;
	regnum = (word1 >> 7) & 7;

	if (format == FTYPE_DBL) {
		insn->is_datasize = 8;
	} else if (format == FTYPE_SNG || format == FTYPE_LNG) {
		insn->is_datasize = 4;
	} else if (format == FTYPE_WRD) {
		insn->is_datasize = 2;
		format = FTYPE_LNG;
	} else if (format == FTYPE_BYT) {
		insn->is_datasize = 1;
		format = FTYPE_LNG;
	} else if (format == FTYPE_EXT) {
		insn->is_datasize = 12;
	} else {
		/* invalid or unsupported operand format */
#if DEBUG_FPE
		printf("  fpu_emul_fstore: invalid format %d\n", format);
#endif
		return SIGFPE;
	}
#if DEBUG_FPE
	printf("  fpu_emul_fstore: format %d, size %d\n",
	    format, insn->is_datasize);
#endif

	fe->fe_fpsr &= ~FPSR_EXCP;

	/* Check an illegal mod/reg */
	modreg = insn->is_opcode & 077;
	if ((modreg >> 3) == 1/*An*/ || modreg >= 072/*PCrel and #imm*/) {
#if DEBUG_FPE
		printf("  fpu_emul_fstore: illegal modreg=0%o\n", modreg);
#endif
		return SIGILL;
	}

	/* Get effective address. */
	sig = fpu_decode_ea(frame, insn, &insn->is_ea, modreg);
	if (sig) {
#if DEBUG_FPE
		printf("  fpu_emul_fstore: failed in decode_ea sig=%d\n", sig);
#endif
		return sig;
	}

	if (insn->is_datasize > 4 && insn->is_ea.ea_flags == EA_DIRECT) {
		/* trying to store dbl or ext into a data register */
#ifdef DEBUG
		printf("  fpu_fstore: attempted to store dbl/ext to reg\n");
#endif
		return SIGILL;
	}

#if DEBUG_FPE
	printf("  fpu_emul_fstore: saving FP%d (%08x,%08x,%08x)\n",
	    regnum, fpregs[regnum * 3], fpregs[regnum * 3 + 1],
	    fpregs[regnum * 3 + 2]);
#endif
	fpu_explode(fe, &fe->fe_f3, FTYPE_EXT, &fpregs[regnum * 3]);
#if DEBUG_FPE
	{
	static const char *class_name[] =
	    { "SNAN", "QNAN", "ZERO", "NUM", "INF" };
	printf("  fpu_emul_fstore: fpn (%s,%c,%d,%08x,%08x,%08x)\n",
	    class_name[fe->fe_f3.fp_class + 2],
	    fe->fe_f3.fp_sign ? '-' : '+', fe->fe_f3.fp_exp,
	    fe->fe_f3.fp_mant[0], fe->fe_f3.fp_mant[1],
	    fe->fe_f3.fp_mant[2]);
	}
#endif
	fpu_implode(fe, &fe->fe_f3, format, buf);

	fpu_store_ea(frame, insn, &insn->is_ea, (char *)buf);
#if DEBUG_FPE
	printf("  fpu_emul_fstore: %08x,%08x,%08x size %d\n",
	    buf[0], buf[1], buf[2], insn->is_datasize);
#endif

	return 0;
}