344 lines
9.1 KiB
C
344 lines
9.1 KiB
C
/* Native-dependent code for the i387.
|
||
Copyright 2000, 2001 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"
|
||
|
||
/* 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, /* FCS_REGNUM (16 bits). */
|
||
12, /* FCOFF_REGNUM. */
|
||
24, /* FDS_REGNUM. */
|
||
20, /* FDOFF_REGNUM. */
|
||
18 /* FOP_REGNUM (bottom 11 bits). */
|
||
};
|
||
|
||
#define FSAVE_ADDR(fsave, regnum) (fsave + fsave_offset[regnum - FP0_REGNUM])
|
||
|
||
|
||
/* 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 >= FIRST_FPU_CTRL_REGNUM
|
||
&& regnum != FCOFF_REGNUM && regnum != FDOFF_REGNUM)
|
||
{
|
||
unsigned int val = *(unsigned short *) (FSAVE_ADDR (fsave, regnum));
|
||
|
||
if (regnum == FOP_REGNUM)
|
||
{
|
||
val &= ((1 << 11) - 1);
|
||
supply_register (regnum, (char *) &val);
|
||
}
|
||
else
|
||
supply_register (regnum, (char *) &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 <= LAST_FPU_CTRL_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 <= LAST_FPU_CTRL_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 >= FIRST_FPU_CTRL_REGNUM
|
||
&& i != FCOFF_REGNUM && i != FDOFF_REGNUM)
|
||
{
|
||
if (i == FOP_REGNUM)
|
||
{
|
||
unsigned short oldval, newval;
|
||
|
||
/* The opcode occupies only 11 bits. */
|
||
oldval = (*(unsigned short *) (FSAVE_ADDR (fsave, i)));
|
||
newval = *(unsigned short *) ®isters[REGISTER_BYTE (i)];
|
||
newval &= ((1 << 11) - 1);
|
||
newval |= oldval & ~((1 << 11) - 1);
|
||
memcpy (FSAVE_ADDR (fsave, i), &newval, 2);
|
||
}
|
||
else
|
||
memcpy (FSAVE_ADDR (fsave, i), ®isters[REGISTER_BYTE (i)], 2);
|
||
}
|
||
else
|
||
memcpy (FSAVE_ADDR (fsave, i), ®isters[REGISTER_BYTE (i)],
|
||
REGISTER_RAW_SIZE (i));
|
||
}
|
||
}
|
||
|
||
|
||
/* 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, /* FCS_REGNUM (16 bits). */
|
||
8, /* FCOFF_REGNUM. */
|
||
20, /* FDS_REGNUM (16 bits). */
|
||
16, /* FDOFF_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);
|
||
|
||
|
||
/* 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 >= FIRST_FPU_CTRL_REGNUM && i < XMM0_REGNUM
|
||
&& i != FCOFF_REGNUM && i != FDOFF_REGNUM)
|
||
{
|
||
unsigned long val = *(unsigned short *) (FXSAVE_ADDR (fxsave, i));
|
||
|
||
if (i == FOP_REGNUM)
|
||
{
|
||
val &= ((1 << 11) - 1);
|
||
supply_register (i, (char *) &val);
|
||
}
|
||
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;
|
||
unsigned long fstat;
|
||
int fpreg;
|
||
int top;
|
||
|
||
fstat = *(unsigned short *) (FXSAVE_ADDR (fxsave, FSTAT_REGNUM));
|
||
top = ((fstat >> 11) & 0x111);
|
||
|
||
for (fpreg = 7; fpreg >= 0; fpreg--)
|
||
{
|
||
int tag = 0x11;
|
||
|
||
if (val & (1 << fpreg))
|
||
{
|
||
int regnum = (fpreg + 8 - top) % 8 + FP0_REGNUM;
|
||
tag = i387_tag (FXSAVE_ADDR (fxsave, regnum));
|
||
}
|
||
|
||
ftag |= tag << (2 * fpreg);
|
||
}
|
||
supply_register (i, (char *) &ftag);
|
||
}
|
||
else
|
||
supply_register (i, (char *) &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 >= FIRST_FPU_CTRL_REGNUM && i < XMM0_REGNUM
|
||
&& i != FCOFF_REGNUM && i != FDOFF_REGNUM)
|
||
{
|
||
if (i == FOP_REGNUM)
|
||
{
|
||
unsigned short oldval, newval;
|
||
|
||
/* The opcode occupies only 11 bits. */
|
||
oldval = (*(unsigned short *) (FXSAVE_ADDR (fxsave, i)));
|
||
newval = *(unsigned short *) ®isters[REGISTER_BYTE (i)];
|
||
newval &= ((1 << 11) - 1);
|
||
newval |= oldval & ~((1 << 11) - 1);
|
||
memcpy (FXSAVE_ADDR (fxsave, i), &newval, 2);
|
||
}
|
||
else if (i == FTAG_REGNUM)
|
||
{
|
||
/* Converting back is much easier. */
|
||
|
||
unsigned char val = 0;
|
||
unsigned short ftag;
|
||
int fpreg;
|
||
|
||
ftag = *(unsigned short *) ®isters[REGISTER_BYTE (i)];
|
||
|
||
for (fpreg = 7; fpreg >= 0; fpreg--)
|
||
{
|
||
int tag = (ftag >> (fpreg * 2)) & 0x11;
|
||
|
||
if (tag != 0x11)
|
||
val |= (1 << fpreg);
|
||
}
|
||
|
||
memcpy (FXSAVE_ADDR (fxsave, i), &val, 2);
|
||
}
|
||
else
|
||
memcpy (FXSAVE_ADDR (fxsave, i),
|
||
®isters[REGISTER_BYTE (i)], 2);
|
||
}
|
||
else
|
||
memcpy (FXSAVE_ADDR (fxsave, i), ®isters[REGISTER_BYTE (i)],
|
||
REGISTER_RAW_SIZE (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 (0x10);
|
||
}
|
||
else if (exponent == 0x0000)
|
||
{
|
||
if (integer)
|
||
{
|
||
/* Valid. */
|
||
return (0x00);
|
||
}
|
||
else
|
||
{
|
||
/* Special. */
|
||
return (0x10);
|
||
}
|
||
}
|
||
else
|
||
{
|
||
if (fraction[0] == 0x0000 && fraction[1] == 0x0000 && !integer)
|
||
{
|
||
/* Zero. */
|
||
return (0x01);
|
||
}
|
||
else
|
||
{
|
||
/* Special. */
|
||
return (0x10);
|
||
}
|
||
}
|
||
}
|