NetBSD/sys/arch/m68k/fpe/fpu_fstore.c
briggs 59422960ea PR 7220 from Ken Nakata:
I've fixed most (not all) m68k FPE bugs that give bogus
calculation results, esp. fsqrt instruction.  Also, the internal FP
representation has been reduced from 115-bit mantissa to 67-bit
mantissa which reduced the required mantissa operation roughly by one
fourth.  I've done an extensive (though not exhaustive - it's
impossible!) test on the internal routines by feeding them randomly
generated FP numbers, and found that the new code is more precise than
MC68040 FPU (it seems to have a rounding bug).

[ Only change was to keep fpu_calcea.c's name instead of renaming to
  fpu_ea.c in Ken's patch.  --akb ]
1999-05-30 20:17:48 +00:00

133 lines
4.0 KiB
C

/* $NetBSD: fpu_fstore.c,v 1.7 1999/05/30 20:17:48 briggs 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/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(fe, insn)
struct fpemu *fe;
struct instruction *insn;
{
struct frame *frame = fe->fe_frame;
u_int *fpregs = fe->fe_fpframe->fpf_regs;
int word1, sig;
int regnum;
int format;
u_int 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;
insn->is_advance = 4;
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
sig = SIGFPE;
}
#if DEBUG_FPE
printf(" fpu_emul_fstore: format %d, size %d\n",
format, insn->is_datasize);
#endif
fe->fe_fpsr &= ~FPSR_EXCP;
/* Get effective address. (modreg=opcode&077) */
sig = fpu_decode_ea(frame, insn, &insn->is_ea, insn->is_opcode);
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 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;
}