-/* Native-dependent code for the i387.
- Copyright 2000, 2001, 2002 Free Software Foundation, Inc.
-
- This file is part of GDB.
-
- This program is free software; you can redistribute it and/or modify
- it under the terms of the GNU General Public License as published by
- the Free Software Foundation; either version 2 of the License, or
- (at your option) any later version.
-
- This program is distributed in the hope that it will be useful,
- but WITHOUT ANY WARRANTY; without even the implied warranty of
- MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
- GNU General Public License for more details.
-
- You should have received a copy of the GNU General Public License
- along with this program; if not, write to the Free Software
- Foundation, Inc., 59 Temple Place - Suite 330,
- Boston, MA 02111-1307, USA. */
-
-#include "defs.h"
-#include "inferior.h"
-#include "value.h"
-#include "regcache.h"
-
-#include "i387-nat.h"
-#include "i386-tdep.h"
-
-/* FIXME: kettenis/2000-05-21: Right now more than a few i386 targets
- define their own routines to manage the floating-point registers in
- GDB's register array. Most (if not all) of these targets use the
- format used by the "fsave" instruction in their communication with
- the OS. They should all be converted to use the routines below. */
-
-/* At fsave_offset[REGNUM] you'll find the offset to the location in
- the data structure used by the "fsave" instruction where GDB
- register REGNUM is stored. */
-
-static int fsave_offset[] =
-{
- 28 + 0 * FPU_REG_RAW_SIZE, /* FP0_REGNUM through ... */
- 28 + 1 * FPU_REG_RAW_SIZE,
- 28 + 2 * FPU_REG_RAW_SIZE,
- 28 + 3 * FPU_REG_RAW_SIZE,
- 28 + 4 * FPU_REG_RAW_SIZE,
- 28 + 5 * FPU_REG_RAW_SIZE,
- 28 + 6 * FPU_REG_RAW_SIZE,
- 28 + 7 * FPU_REG_RAW_SIZE, /* ... FP7_REGNUM. */
- 0, /* FCTRL_REGNUM (16 bits). */
- 4, /* FSTAT_REGNUM (16 bits). */
- 8, /* FTAG_REGNUM (16 bits). */
- 16, /* FISEG_REGNUM (16 bits). */
- 12, /* FIOFF_REGNUM. */
- 24, /* FOSEG_REGNUM. */
- 20, /* FOOFF_REGNUM. */
- 18 /* FOP_REGNUM (bottom 11 bits). */
-};
-
-#define FSAVE_ADDR(fsave, regnum) (fsave + fsave_offset[regnum - FP0_REGNUM])
-\f
-
-/* Fill register REGNUM in GDB's register array with the appropriate
- value from *FSAVE. This function masks off any of the reserved
- bits in *FSAVE. */
-
-void
-i387_supply_register (int regnum, char *fsave)
-{
- /* Most of the FPU control registers occupy only 16 bits in
- the fsave area. Give those a special treatment. */
- if (regnum >= FPC_REGNUM
- && regnum != FIOFF_REGNUM && regnum != FOOFF_REGNUM)
- {
- unsigned char val[4];
-
- memcpy (val, FSAVE_ADDR (fsave, regnum), 2);
- val[2] = val[3] = 0;
- if (regnum == FOP_REGNUM)
- val[1] &= ((1 << 3) - 1);
- supply_register (regnum, val);
- }
- else
- supply_register (regnum, FSAVE_ADDR (fsave, regnum));
-}
-
-/* Fill GDB's register array with the floating-point register values
- in *FSAVE. This function masks off any of the reserved
- bits in *FSAVE. */
-
-void
-i387_supply_fsave (char *fsave)
-{
- int i;
-
- for (i = FP0_REGNUM; i < XMM0_REGNUM; i++)
- i387_supply_register (i, fsave);
-}
-
-/* Fill register REGNUM (if it is a floating-point register) in *FSAVE
- with the value in GDB's register array. If REGNUM is -1, do this
- for all registers. This function doesn't touch any of the reserved
- bits in *FSAVE. */
-
-void
-i387_fill_fsave (char *fsave, int regnum)
-{
- int i;
-
- for (i = FP0_REGNUM; i < XMM0_REGNUM; i++)
- if (regnum == -1 || regnum == i)
- {
- /* Most of the FPU control registers occupy only 16 bits in
- the fsave area. Give those a special treatment. */
- if (i >= FPC_REGNUM
- && i != FIOFF_REGNUM && i != FOOFF_REGNUM)
- {
- unsigned char buf[4];
-
- regcache_collect (i, buf);
-
- if (i == FOP_REGNUM)
- {
- /* The opcode occupies only 11 bits. Make sure we
- don't touch the other bits. */
- buf[1] &= ((1 << 3) - 1);
- buf[1] |= ((FSAVE_ADDR (fsave, i))[1] & ~((1 << 3) - 1));
- }
- memcpy (FSAVE_ADDR (fsave, i), buf, 2);
- }
- else
- regcache_collect (i, FSAVE_ADDR (fsave, i));
- }
-}
-\f
-
-/* At fxsave_offset[REGNUM] you'll find the offset to the location in
- the data structure used by the "fxsave" instruction where GDB
- register REGNUM is stored. */
-
-static int fxsave_offset[] =
-{
- 32, /* FP0_REGNUM through ... */
- 48,
- 64,
- 80,
- 96,
- 112,
- 128,
- 144, /* ... FP7_REGNUM (80 bits each). */
- 0, /* FCTRL_REGNUM (16 bits). */
- 2, /* FSTAT_REGNUM (16 bits). */
- 4, /* FTAG_REGNUM (16 bits). */
- 12, /* FISEG_REGNUM (16 bits). */
- 8, /* FIOFF_REGNUM. */
- 20, /* FOSEG_REGNUM (16 bits). */
- 16, /* FOOFF_REGNUM. */
- 6, /* FOP_REGNUM (bottom 11 bits). */
- 160, /* XMM0_REGNUM through ... */
- 176,
- 192,
- 208,
- 224,
- 240,
- 256,
- 272, /* ... XMM7_REGNUM (128 bits each). */
- 24, /* MXCSR_REGNUM. */
-};
-
-#define FXSAVE_ADDR(fxsave, regnum) \
- (fxsave + fxsave_offset[regnum - FP0_REGNUM])
-
-static int i387_tag (unsigned char *raw);
-\f
-
-/* Fill GDB's register array with the floating-point and SSE register
- values in *FXSAVE. This function masks off any of the reserved
- bits in *FXSAVE. */
-
-void
-i387_supply_fxsave (char *fxsave)
-{
- int i;
-
- for (i = FP0_REGNUM; i <= MXCSR_REGNUM; i++)
- {
- /* Most of the FPU control registers occupy only 16 bits in
- the fxsave area. Give those a special treatment. */
- if (i >= FPC_REGNUM && i < XMM0_REGNUM
- && i != FIOFF_REGNUM && i != FOOFF_REGNUM)
- {
- unsigned char val[4];
-
- memcpy (val, FXSAVE_ADDR (fxsave, i), 2);
- val[2] = val[3] = 0;
- if (i == FOP_REGNUM)
- val[1] &= ((1 << 3) - 1);
- else if (i== FTAG_REGNUM)
- {
- /* The fxsave area contains a simplified version of the
- tag word. We have to look at the actual 80-bit FP
- data to recreate the traditional i387 tag word. */
-
- unsigned long ftag = 0;
- int fpreg;
- int top;
-
- top = (((FXSAVE_ADDR (fxsave, FSTAT_REGNUM))[1] >> 3) & 0x7);
-
- for (fpreg = 7; fpreg >= 0; fpreg--)
- {
- int tag;
-
- if (val[0] & (1 << fpreg))
- {
- int regnum = (fpreg + 8 - top) % 8 + FP0_REGNUM;
- tag = i387_tag (FXSAVE_ADDR (fxsave, regnum));
- }
- else
- tag = 3; /* Empty */
-
- ftag |= tag << (2 * fpreg);
- }
- val[0] = ftag & 0xff;
- val[1] = (ftag >> 8) & 0xff;
- }
- supply_register (i, val);
- }
- else
- supply_register (i, FXSAVE_ADDR (fxsave, i));
- }
-}
-
-/* Fill register REGNUM (if it is a floating-point or SSE register) in
- *FXSAVE with the value in GDB's register array. If REGNUM is -1, do
- this for all registers. This function doesn't touch any of the
- reserved bits in *FXSAVE. */
-
-void
-i387_fill_fxsave (char *fxsave, int regnum)
-{
- int i;
-
- for (i = FP0_REGNUM; i <= MXCSR_REGNUM; i++)
- if (regnum == -1 || regnum == i)
- {
- /* Most of the FPU control registers occupy only 16 bits in
- the fxsave area. Give those a special treatment. */
- if (i >= FPC_REGNUM && i < XMM0_REGNUM
- && i != FIOFF_REGNUM && i != FDOFF_REGNUM)
- {
- unsigned char buf[4];
-
- regcache_collect (i, buf);
-
- if (i == FOP_REGNUM)
- {
- /* The opcode occupies only 11 bits. Make sure we
- don't touch the other bits. */
- buf[1] &= ((1 << 3) - 1);
- buf[1] |= ((FXSAVE_ADDR (fxsave, i))[1] & ~((1 << 3) - 1));
- }
- else if (i == FTAG_REGNUM)
- {
- /* Converting back is much easier. */
-
- unsigned short ftag;
- int fpreg;
-
- ftag = (buf[1] << 8) | buf[0];
- buf[0] = 0;
- buf[1] = 0;
-
- for (fpreg = 7; fpreg >= 0; fpreg--)
- {
- int tag = (ftag >> (fpreg * 2)) & 3;
-
- if (tag != 3)
- buf[0] |= (1 << fpreg);
- }
- }
- memcpy (FXSAVE_ADDR (fxsave, i), buf, 2);
- }
- else
- regcache_collect (i, FXSAVE_ADDR (fxsave, i));
- }
-}
-
-/* Recreate the FTW (tag word) valid bits from the 80-bit FP data in
- *RAW. */
-
-static int
-i387_tag (unsigned char *raw)
-{
- int integer;
- unsigned int exponent;
- unsigned long fraction[2];
-
- integer = raw[7] & 0x80;
- exponent = (((raw[9] & 0x7f) << 8) | raw[8]);
- fraction[0] = ((raw[3] << 24) | (raw[2] << 16) | (raw[1] << 8) | raw[0]);
- fraction[1] = (((raw[7] & 0x7f) << 24) | (raw[6] << 16)
- | (raw[5] << 8) | raw[4]);
-
- if (exponent == 0x7fff)
- {
- /* Special. */
- return (2);
- }
- else if (exponent == 0x0000)
- {
- if (fraction[0] == 0x0000 && fraction[1] == 0x0000 && !integer)
- {
- /* Zero. */
- return (1);
- }
- else
- {
- /* Special. */
- return (2);
- }
- }
- else
- {
- if (integer)
- {
- /* Valid. */
- return (0);
- }
- else
- {
- /* Special. */
- return (2);
- }
- }
-}
projects / thirdparty / binutils-gdb.git / commitdiff
