mirror of
https://github.com/darlinghq/darling-gdb.git
synced 2024-12-15 00:00:20 +00:00
784 lines
22 KiB
C
784 lines
22 KiB
C
/* Intel 387 floating point stuff.
|
||
|
||
Copyright (C) 1988, 1989, 1991, 1992, 1993, 1994, 1998, 1999, 2000, 2001,
|
||
2002, 2003, 2004, 2005, 2007, 2008 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 3 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, see <http://www.gnu.org/licenses/>. */
|
||
|
||
#include "defs.h"
|
||
#include "doublest.h"
|
||
#include "floatformat.h"
|
||
#include "frame.h"
|
||
#include "gdbcore.h"
|
||
#include "inferior.h"
|
||
#include "language.h"
|
||
#include "regcache.h"
|
||
#include "value.h"
|
||
|
||
#include "gdb_assert.h"
|
||
#include "gdb_string.h"
|
||
|
||
#include "i386-tdep.h"
|
||
#include "i387-tdep.h"
|
||
|
||
/* Print the floating point number specified by RAW. */
|
||
|
||
static void
|
||
print_i387_value (const gdb_byte *raw, struct ui_file *file)
|
||
{
|
||
DOUBLEST value;
|
||
|
||
/* Using extract_typed_floating here might affect the representation
|
||
of certain numbers such as NaNs, even if GDB is running natively.
|
||
This is fine since our caller already detects such special
|
||
numbers and we print the hexadecimal representation anyway. */
|
||
value = extract_typed_floating (raw, builtin_type_i387_ext);
|
||
|
||
/* We try to print 19 digits. The last digit may or may not contain
|
||
garbage, but we'd better print one too many. We need enough room
|
||
to print the value, 1 position for the sign, 1 for the decimal
|
||
point, 19 for the digits and 6 for the exponent adds up to 27. */
|
||
#ifdef PRINTF_HAS_LONG_DOUBLE
|
||
fprintf_filtered (file, " %-+27.19Lg", (long double) value);
|
||
#else
|
||
fprintf_filtered (file, " %-+27.19g", (double) value);
|
||
#endif
|
||
}
|
||
|
||
/* Print the classification for the register contents RAW. */
|
||
|
||
static void
|
||
print_i387_ext (const gdb_byte *raw, struct ui_file *file)
|
||
{
|
||
int sign;
|
||
int integer;
|
||
unsigned int exponent;
|
||
unsigned long fraction[2];
|
||
|
||
sign = raw[9] & 0x80;
|
||
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 && integer)
|
||
{
|
||
if (fraction[0] == 0x00000000 && fraction[1] == 0x00000000)
|
||
/* Infinity. */
|
||
fprintf_filtered (file, " %cInf", (sign ? '-' : '+'));
|
||
else if (sign && fraction[0] == 0x00000000 && fraction[1] == 0x40000000)
|
||
/* Real Indefinite (QNaN). */
|
||
fputs_unfiltered (" Real Indefinite (QNaN)", file);
|
||
else if (fraction[1] & 0x40000000)
|
||
/* QNaN. */
|
||
fputs_filtered (" QNaN", file);
|
||
else
|
||
/* SNaN. */
|
||
fputs_filtered (" SNaN", file);
|
||
}
|
||
else if (exponent < 0x7fff && exponent > 0x0000 && integer)
|
||
/* Normal. */
|
||
print_i387_value (raw, file);
|
||
else if (exponent == 0x0000)
|
||
{
|
||
/* Denormal or zero. */
|
||
print_i387_value (raw, file);
|
||
|
||
if (integer)
|
||
/* Pseudo-denormal. */
|
||
fputs_filtered (" Pseudo-denormal", file);
|
||
else if (fraction[0] || fraction[1])
|
||
/* Denormal. */
|
||
fputs_filtered (" Denormal", file);
|
||
}
|
||
else
|
||
/* Unsupported. */
|
||
fputs_filtered (" Unsupported", file);
|
||
}
|
||
|
||
/* Print the status word STATUS. */
|
||
|
||
static void
|
||
print_i387_status_word (unsigned int status, struct ui_file *file)
|
||
{
|
||
fprintf_filtered (file, "Status Word: %s",
|
||
hex_string_custom (status, 4));
|
||
fputs_filtered (" ", file);
|
||
fprintf_filtered (file, " %s", (status & 0x0001) ? "IE" : " ");
|
||
fprintf_filtered (file, " %s", (status & 0x0002) ? "DE" : " ");
|
||
fprintf_filtered (file, " %s", (status & 0x0004) ? "ZE" : " ");
|
||
fprintf_filtered (file, " %s", (status & 0x0008) ? "OE" : " ");
|
||
fprintf_filtered (file, " %s", (status & 0x0010) ? "UE" : " ");
|
||
fprintf_filtered (file, " %s", (status & 0x0020) ? "PE" : " ");
|
||
fputs_filtered (" ", file);
|
||
fprintf_filtered (file, " %s", (status & 0x0080) ? "ES" : " ");
|
||
fputs_filtered (" ", file);
|
||
fprintf_filtered (file, " %s", (status & 0x0040) ? "SF" : " ");
|
||
fputs_filtered (" ", file);
|
||
fprintf_filtered (file, " %s", (status & 0x0100) ? "C0" : " ");
|
||
fprintf_filtered (file, " %s", (status & 0x0200) ? "C1" : " ");
|
||
fprintf_filtered (file, " %s", (status & 0x0400) ? "C2" : " ");
|
||
fprintf_filtered (file, " %s", (status & 0x4000) ? "C3" : " ");
|
||
|
||
fputs_filtered ("\n", file);
|
||
|
||
fprintf_filtered (file,
|
||
" TOP: %d\n", ((status >> 11) & 7));
|
||
}
|
||
|
||
/* Print the control word CONTROL. */
|
||
|
||
static void
|
||
print_i387_control_word (unsigned int control, struct ui_file *file)
|
||
{
|
||
fprintf_filtered (file, "Control Word: %s",
|
||
hex_string_custom (control, 4));
|
||
fputs_filtered (" ", file);
|
||
fprintf_filtered (file, " %s", (control & 0x0001) ? "IM" : " ");
|
||
fprintf_filtered (file, " %s", (control & 0x0002) ? "DM" : " ");
|
||
fprintf_filtered (file, " %s", (control & 0x0004) ? "ZM" : " ");
|
||
fprintf_filtered (file, " %s", (control & 0x0008) ? "OM" : " ");
|
||
fprintf_filtered (file, " %s", (control & 0x0010) ? "UM" : " ");
|
||
fprintf_filtered (file, " %s", (control & 0x0020) ? "PM" : " ");
|
||
|
||
fputs_filtered ("\n", file);
|
||
|
||
fputs_filtered (" PC: ", file);
|
||
switch ((control >> 8) & 3)
|
||
{
|
||
case 0:
|
||
fputs_filtered ("Single Precision (24-bits)\n", file);
|
||
break;
|
||
case 1:
|
||
fputs_filtered ("Reserved\n", file);
|
||
break;
|
||
case 2:
|
||
fputs_filtered ("Double Precision (53-bits)\n", file);
|
||
break;
|
||
case 3:
|
||
fputs_filtered ("Extended Precision (64-bits)\n", file);
|
||
break;
|
||
}
|
||
|
||
fputs_filtered (" RC: ", file);
|
||
switch ((control >> 10) & 3)
|
||
{
|
||
case 0:
|
||
fputs_filtered ("Round to nearest\n", file);
|
||
break;
|
||
case 1:
|
||
fputs_filtered ("Round down\n", file);
|
||
break;
|
||
case 2:
|
||
fputs_filtered ("Round up\n", file);
|
||
break;
|
||
case 3:
|
||
fputs_filtered ("Round toward zero\n", file);
|
||
break;
|
||
}
|
||
}
|
||
|
||
/* Print out the i387 floating point state. Note that we ignore FRAME
|
||
in the code below. That's OK since floating-point registers are
|
||
never saved on the stack. */
|
||
|
||
void
|
||
i387_print_float_info (struct gdbarch *gdbarch, struct ui_file *file,
|
||
struct frame_info *frame, const char *args)
|
||
{
|
||
struct gdbarch_tdep *tdep = gdbarch_tdep (get_frame_arch (frame));
|
||
gdb_byte buf[4];
|
||
ULONGEST fctrl;
|
||
ULONGEST fstat;
|
||
ULONGEST ftag;
|
||
ULONGEST fiseg;
|
||
ULONGEST fioff;
|
||
ULONGEST foseg;
|
||
ULONGEST fooff;
|
||
ULONGEST fop;
|
||
int fpreg;
|
||
int top;
|
||
|
||
gdb_assert (gdbarch == get_frame_arch (frame));
|
||
|
||
/* Define I387_ST0_REGNUM such that we use the proper definitions
|
||
for FRAME's architecture. */
|
||
#define I387_ST0_REGNUM tdep->st0_regnum
|
||
|
||
fctrl = get_frame_register_unsigned (frame, I387_FCTRL_REGNUM);
|
||
fstat = get_frame_register_unsigned (frame, I387_FSTAT_REGNUM);
|
||
ftag = get_frame_register_unsigned (frame, I387_FTAG_REGNUM);
|
||
fiseg = get_frame_register_unsigned (frame, I387_FISEG_REGNUM);
|
||
fioff = get_frame_register_unsigned (frame, I387_FIOFF_REGNUM);
|
||
foseg = get_frame_register_unsigned (frame, I387_FOSEG_REGNUM);
|
||
fooff = get_frame_register_unsigned (frame, I387_FOOFF_REGNUM);
|
||
fop = get_frame_register_unsigned (frame, I387_FOP_REGNUM);
|
||
|
||
top = ((fstat >> 11) & 7);
|
||
|
||
for (fpreg = 7; fpreg >= 0; fpreg--)
|
||
{
|
||
gdb_byte raw[I386_MAX_REGISTER_SIZE];
|
||
int tag = (ftag >> (fpreg * 2)) & 3;
|
||
int i;
|
||
|
||
fprintf_filtered (file, "%sR%d: ", fpreg == top ? "=>" : " ", fpreg);
|
||
|
||
switch (tag)
|
||
{
|
||
case 0:
|
||
fputs_filtered ("Valid ", file);
|
||
break;
|
||
case 1:
|
||
fputs_filtered ("Zero ", file);
|
||
break;
|
||
case 2:
|
||
fputs_filtered ("Special ", file);
|
||
break;
|
||
case 3:
|
||
fputs_filtered ("Empty ", file);
|
||
break;
|
||
}
|
||
|
||
get_frame_register (frame, (fpreg + 8 - top) % 8 + I387_ST0_REGNUM, raw);
|
||
|
||
fputs_filtered ("0x", file);
|
||
for (i = 9; i >= 0; i--)
|
||
fprintf_filtered (file, "%02x", raw[i]);
|
||
|
||
if (tag != 3)
|
||
print_i387_ext (raw, file);
|
||
|
||
fputs_filtered ("\n", file);
|
||
}
|
||
|
||
fputs_filtered ("\n", file);
|
||
|
||
print_i387_status_word (fstat, file);
|
||
print_i387_control_word (fctrl, file);
|
||
fprintf_filtered (file, "Tag Word: %s\n",
|
||
hex_string_custom (ftag, 4));
|
||
fprintf_filtered (file, "Instruction Pointer: %s:",
|
||
hex_string_custom (fiseg, 2));
|
||
fprintf_filtered (file, "%s\n", hex_string_custom (fioff, 8));
|
||
fprintf_filtered (file, "Operand Pointer: %s:",
|
||
hex_string_custom (foseg, 2));
|
||
fprintf_filtered (file, "%s\n", hex_string_custom (fooff, 8));
|
||
fprintf_filtered (file, "Opcode: %s\n",
|
||
hex_string_custom (fop ? (fop | 0xd800) : 0, 4));
|
||
|
||
#undef I387_ST0_REGNUM
|
||
}
|
||
|
||
|
||
/* Return nonzero if a value of type TYPE stored in register REGNUM
|
||
needs any special handling. */
|
||
|
||
int
|
||
i387_convert_register_p (struct gdbarch *gdbarch, int regnum, struct type *type)
|
||
{
|
||
if (i386_fp_regnum_p (regnum))
|
||
{
|
||
/* Floating point registers must be converted unless we are
|
||
accessing them in their hardware type. */
|
||
if (type == builtin_type_i387_ext)
|
||
return 0;
|
||
else
|
||
return 1;
|
||
}
|
||
|
||
return 0;
|
||
}
|
||
|
||
/* Read a value of type TYPE from register REGNUM in frame FRAME, and
|
||
return its contents in TO. */
|
||
|
||
void
|
||
i387_register_to_value (struct frame_info *frame, int regnum,
|
||
struct type *type, gdb_byte *to)
|
||
{
|
||
gdb_byte from[I386_MAX_REGISTER_SIZE];
|
||
|
||
gdb_assert (i386_fp_regnum_p (regnum));
|
||
|
||
/* We only support floating-point values. */
|
||
if (TYPE_CODE (type) != TYPE_CODE_FLT)
|
||
{
|
||
warning (_("Cannot convert floating-point register value "
|
||
"to non-floating-point type."));
|
||
return;
|
||
}
|
||
|
||
/* Convert to TYPE. */
|
||
get_frame_register (frame, regnum, from);
|
||
convert_typed_floating (from, builtin_type_i387_ext, to, type);
|
||
}
|
||
|
||
/* Write the contents FROM of a value of type TYPE into register
|
||
REGNUM in frame FRAME. */
|
||
|
||
void
|
||
i387_value_to_register (struct frame_info *frame, int regnum,
|
||
struct type *type, const gdb_byte *from)
|
||
{
|
||
gdb_byte to[I386_MAX_REGISTER_SIZE];
|
||
|
||
gdb_assert (i386_fp_regnum_p (regnum));
|
||
|
||
/* We only support floating-point values. */
|
||
if (TYPE_CODE (type) != TYPE_CODE_FLT)
|
||
{
|
||
warning (_("Cannot convert non-floating-point type "
|
||
"to floating-point register value."));
|
||
return;
|
||
}
|
||
|
||
/* Convert from TYPE. */
|
||
convert_typed_floating (from, type, to, builtin_type_i387_ext);
|
||
put_frame_register (frame, regnum, to);
|
||
}
|
||
|
||
|
||
/* Handle FSAVE and FXSAVE formats. */
|
||
|
||
/* 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 * 10, /* %st(0) ... */
|
||
28 + 1 * 10,
|
||
28 + 2 * 10,
|
||
28 + 3 * 10,
|
||
28 + 4 * 10,
|
||
28 + 5 * 10,
|
||
28 + 6 * 10,
|
||
28 + 7 * 10, /* ... %st(7). */
|
||
0, /* `fctrl' (16 bits). */
|
||
4, /* `fstat' (16 bits). */
|
||
8, /* `ftag' (16 bits). */
|
||
16, /* `fiseg' (16 bits). */
|
||
12, /* `fioff'. */
|
||
24, /* `foseg' (16 bits). */
|
||
20, /* `fooff'. */
|
||
18 /* `fop' (bottom 11 bits). */
|
||
};
|
||
|
||
#define FSAVE_ADDR(fsave, regnum) \
|
||
(fsave + fsave_offset[regnum - I387_ST0_REGNUM])
|
||
|
||
|
||
/* Fill register REGNUM in REGCACHE with the appropriate value from
|
||
*FSAVE. This function masks off any of the reserved bits in
|
||
*FSAVE. */
|
||
|
||
void
|
||
i387_supply_fsave (struct regcache *regcache, int regnum, const void *fsave)
|
||
{
|
||
struct gdbarch_tdep *tdep = gdbarch_tdep (get_regcache_arch (regcache));
|
||
const gdb_byte *regs = fsave;
|
||
int i;
|
||
|
||
gdb_assert (tdep->st0_regnum >= I386_ST0_REGNUM);
|
||
|
||
/* Define I387_ST0_REGNUM and I387_NUM_XMM_REGS such that we use the
|
||
proper definitions for REGCACHE's architecture. */
|
||
|
||
#define I387_ST0_REGNUM tdep->st0_regnum
|
||
#define I387_NUM_XMM_REGS tdep->num_xmm_regs
|
||
|
||
for (i = I387_ST0_REGNUM; i < I387_XMM0_REGNUM; i++)
|
||
if (regnum == -1 || regnum == i)
|
||
{
|
||
if (fsave == NULL)
|
||
{
|
||
regcache_raw_supply (regcache, i, NULL);
|
||
continue;
|
||
}
|
||
|
||
/* Most of the FPU control registers occupy only 16 bits in the
|
||
fsave area. Give those a special treatment. */
|
||
if (i >= I387_FCTRL_REGNUM
|
||
&& i != I387_FIOFF_REGNUM && i != I387_FOOFF_REGNUM)
|
||
{
|
||
gdb_byte val[4];
|
||
|
||
memcpy (val, FSAVE_ADDR (regs, i), 2);
|
||
val[2] = val[3] = 0;
|
||
if (i == I387_FOP_REGNUM)
|
||
val[1] &= ((1 << 3) - 1);
|
||
regcache_raw_supply (regcache, i, val);
|
||
}
|
||
else
|
||
regcache_raw_supply (regcache, i, FSAVE_ADDR (regs, i));
|
||
}
|
||
|
||
/* Provide dummy values for the SSE registers. */
|
||
for (i = I387_XMM0_REGNUM; i < I387_MXCSR_REGNUM; i++)
|
||
if (regnum == -1 || regnum == i)
|
||
regcache_raw_supply (regcache, i, NULL);
|
||
if (regnum == -1 || regnum == I387_MXCSR_REGNUM)
|
||
{
|
||
gdb_byte buf[4];
|
||
|
||
store_unsigned_integer (buf, 4, 0x1f80);
|
||
regcache_raw_supply (regcache, I387_MXCSR_REGNUM, buf);
|
||
}
|
||
|
||
#undef I387_ST0_REGNUM
|
||
#undef I387_NUM_XMM_REGS
|
||
}
|
||
|
||
/* Fill register REGNUM (if it is a floating-point register) in *FSAVE
|
||
with the value from REGCACHE. If REGNUM is -1, do this for all
|
||
registers. This function doesn't touch any of the reserved bits in
|
||
*FSAVE. */
|
||
|
||
void
|
||
i387_collect_fsave (const struct regcache *regcache, int regnum, void *fsave)
|
||
{
|
||
struct gdbarch_tdep *tdep = gdbarch_tdep (get_regcache_arch (regcache));
|
||
gdb_byte *regs = fsave;
|
||
int i;
|
||
|
||
gdb_assert (tdep->st0_regnum >= I386_ST0_REGNUM);
|
||
|
||
/* Define I387_ST0_REGNUM such that we use the proper definitions
|
||
for REGCACHE's architecture. */
|
||
#define I387_ST0_REGNUM tdep->st0_regnum
|
||
|
||
for (i = I387_ST0_REGNUM; i < I387_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 >= I387_FCTRL_REGNUM
|
||
&& i != I387_FIOFF_REGNUM && i != I387_FOOFF_REGNUM)
|
||
{
|
||
gdb_byte buf[4];
|
||
|
||
regcache_raw_collect (regcache, i, buf);
|
||
|
||
if (i == I387_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 (regs, i))[1] & ~((1 << 3) - 1));
|
||
}
|
||
memcpy (FSAVE_ADDR (regs, i), buf, 2);
|
||
}
|
||
else
|
||
regcache_raw_collect (regcache, i, FSAVE_ADDR (regs, i));
|
||
}
|
||
#undef I387_ST0_REGNUM
|
||
}
|
||
|
||
|
||
/* 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, /* %st(0) through ... */
|
||
48,
|
||
64,
|
||
80,
|
||
96,
|
||
112,
|
||
128,
|
||
144, /* ... %st(7) (80 bits each). */
|
||
0, /* `fctrl' (16 bits). */
|
||
2, /* `fstat' (16 bits). */
|
||
4, /* `ftag' (16 bits). */
|
||
12, /* `fiseg' (16 bits). */
|
||
8, /* `fioff'. */
|
||
20, /* `foseg' (16 bits). */
|
||
16, /* `fooff'. */
|
||
6, /* `fop' (bottom 11 bits). */
|
||
160 + 0 * 16, /* %xmm0 through ... */
|
||
160 + 1 * 16,
|
||
160 + 2 * 16,
|
||
160 + 3 * 16,
|
||
160 + 4 * 16,
|
||
160 + 5 * 16,
|
||
160 + 6 * 16,
|
||
160 + 7 * 16,
|
||
160 + 8 * 16,
|
||
160 + 9 * 16,
|
||
160 + 10 * 16,
|
||
160 + 11 * 16,
|
||
160 + 12 * 16,
|
||
160 + 13 * 16,
|
||
160 + 14 * 16,
|
||
160 + 15 * 16, /* ... %xmm15 (128 bits each). */
|
||
};
|
||
|
||
#define FXSAVE_ADDR(fxsave, regnum) \
|
||
(fxsave + fxsave_offset[regnum - I387_ST0_REGNUM])
|
||
|
||
/* We made an unfortunate choice in putting %mxcsr after the SSE
|
||
registers %xmm0-%xmm7 instead of before, since it makes supporting
|
||
the registers %xmm8-%xmm15 on AMD64 a bit involved. Therefore we
|
||
don't include the offset for %mxcsr here above. */
|
||
|
||
#define FXSAVE_MXCSR_ADDR(fxsave) (fxsave + 24)
|
||
|
||
static int i387_tag (const gdb_byte *raw);
|
||
|
||
|
||
/* Fill register REGNUM in REGCACHE with the appropriate
|
||
floating-point or SSE register value from *FXSAVE. This function
|
||
masks off any of the reserved bits in *FXSAVE. */
|
||
|
||
void
|
||
i387_supply_fxsave (struct regcache *regcache, int regnum, const void *fxsave)
|
||
{
|
||
struct gdbarch_tdep *tdep = gdbarch_tdep (get_regcache_arch (regcache));
|
||
const gdb_byte *regs = fxsave;
|
||
int i;
|
||
|
||
gdb_assert (tdep->st0_regnum >= I386_ST0_REGNUM);
|
||
gdb_assert (tdep->num_xmm_regs > 0);
|
||
|
||
/* Define I387_ST0_REGNUM and I387_NUM_XMM_REGS such that we use the
|
||
proper definitions for REGCACHE's architecture. */
|
||
|
||
#define I387_ST0_REGNUM tdep->st0_regnum
|
||
#define I387_NUM_XMM_REGS tdep->num_xmm_regs
|
||
|
||
for (i = I387_ST0_REGNUM; i < I387_MXCSR_REGNUM; i++)
|
||
if (regnum == -1 || regnum == i)
|
||
{
|
||
if (regs == NULL)
|
||
{
|
||
regcache_raw_supply (regcache, i, NULL);
|
||
continue;
|
||
}
|
||
|
||
/* Most of the FPU control registers occupy only 16 bits in
|
||
the fxsave area. Give those a special treatment. */
|
||
if (i >= I387_FCTRL_REGNUM && i < I387_XMM0_REGNUM
|
||
&& i != I387_FIOFF_REGNUM && i != I387_FOOFF_REGNUM)
|
||
{
|
||
gdb_byte val[4];
|
||
|
||
memcpy (val, FXSAVE_ADDR (regs, i), 2);
|
||
val[2] = val[3] = 0;
|
||
if (i == I387_FOP_REGNUM)
|
||
val[1] &= ((1 << 3) - 1);
|
||
else if (i== I387_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 (regs, I387_FSTAT_REGNUM))[1] >> 3);
|
||
top &= 0x7;
|
||
|
||
for (fpreg = 7; fpreg >= 0; fpreg--)
|
||
{
|
||
int tag;
|
||
|
||
if (val[0] & (1 << fpreg))
|
||
{
|
||
int regnum = (fpreg + 8 - top) % 8 + I387_ST0_REGNUM;
|
||
tag = i387_tag (FXSAVE_ADDR (regs, regnum));
|
||
}
|
||
else
|
||
tag = 3; /* Empty */
|
||
|
||
ftag |= tag << (2 * fpreg);
|
||
}
|
||
val[0] = ftag & 0xff;
|
||
val[1] = (ftag >> 8) & 0xff;
|
||
}
|
||
regcache_raw_supply (regcache, i, val);
|
||
}
|
||
else
|
||
regcache_raw_supply (regcache, i, FXSAVE_ADDR (regs, i));
|
||
}
|
||
|
||
if (regnum == I387_MXCSR_REGNUM || regnum == -1)
|
||
{
|
||
if (regs == NULL)
|
||
regcache_raw_supply (regcache, I387_MXCSR_REGNUM, NULL);
|
||
else
|
||
regcache_raw_supply (regcache, I387_MXCSR_REGNUM,
|
||
FXSAVE_MXCSR_ADDR (regs));
|
||
}
|
||
|
||
#undef I387_ST0_REGNUM
|
||
#undef I387_NUM_XMM_REGS
|
||
}
|
||
|
||
/* Fill register REGNUM (if it is a floating-point or SSE register) in
|
||
*FXSAVE with the value from REGCACHE. If REGNUM is -1, do this for
|
||
all registers. This function doesn't touch any of the reserved
|
||
bits in *FXSAVE. */
|
||
|
||
void
|
||
i387_collect_fxsave (const struct regcache *regcache, int regnum, void *fxsave)
|
||
{
|
||
struct gdbarch_tdep *tdep = gdbarch_tdep (get_regcache_arch (regcache));
|
||
gdb_byte *regs = fxsave;
|
||
int i;
|
||
|
||
gdb_assert (tdep->st0_regnum >= I386_ST0_REGNUM);
|
||
gdb_assert (tdep->num_xmm_regs > 0);
|
||
|
||
/* Define I387_ST0_REGNUM and I387_NUM_XMM_REGS such that we use the
|
||
proper definitions for REGCACHE's architecture. */
|
||
|
||
#define I387_ST0_REGNUM tdep->st0_regnum
|
||
#define I387_NUM_XMM_REGS tdep->num_xmm_regs
|
||
|
||
for (i = I387_ST0_REGNUM; i < I387_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 >= I387_FCTRL_REGNUM && i < I387_XMM0_REGNUM
|
||
&& i != I387_FIOFF_REGNUM && i != I387_FOOFF_REGNUM)
|
||
{
|
||
gdb_byte buf[4];
|
||
|
||
regcache_raw_collect (regcache, i, buf);
|
||
|
||
if (i == I387_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 (regs, i))[1] & ~((1 << 3) - 1));
|
||
}
|
||
else if (i == I387_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 (regs, i), buf, 2);
|
||
}
|
||
else
|
||
regcache_raw_collect (regcache, i, FXSAVE_ADDR (regs, i));
|
||
}
|
||
|
||
if (regnum == I387_MXCSR_REGNUM || regnum == -1)
|
||
regcache_raw_collect (regcache, I387_MXCSR_REGNUM,
|
||
FXSAVE_MXCSR_ADDR (regs));
|
||
|
||
#undef I387_ST0_REGNUM
|
||
#undef I387_NUM_XMM_REGS
|
||
}
|
||
|
||
/* Recreate the FTW (tag word) valid bits from the 80-bit FP data in
|
||
*RAW. */
|
||
|
||
static int
|
||
i387_tag (const gdb_byte *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);
|
||
}
|
||
}
|
||
}
|
||
|
||
/* Prepare the FPU stack in REGCACHE for a function return. */
|
||
|
||
void
|
||
i387_return_value (struct gdbarch *gdbarch, struct regcache *regcache)
|
||
{
|
||
struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch);
|
||
ULONGEST fstat;
|
||
|
||
/* Define I387_ST0_REGNUM such that we use the proper
|
||
definitions for the architecture. */
|
||
#define I387_ST0_REGNUM tdep->st0_regnum
|
||
|
||
/* Set the top of the floating-point register stack to 7. The
|
||
actual value doesn't really matter, but 7 is what a normal
|
||
function return would end up with if the program started out with
|
||
a freshly initialized FPU. */
|
||
regcache_raw_read_unsigned (regcache, I387_FSTAT_REGNUM, &fstat);
|
||
fstat |= (7 << 11);
|
||
regcache_raw_write_unsigned (regcache, I387_FSTAT_REGNUM, fstat);
|
||
|
||
/* Mark %st(1) through %st(7) as empty. Since we set the top of the
|
||
floating-point register stack to 7, the appropriate value for the
|
||
tag word is 0x3fff. */
|
||
regcache_raw_write_unsigned (regcache, I387_FTAG_REGNUM, 0x3fff);
|
||
|
||
#undef I387_ST0_REGNUM
|
||
}
|