binutils-gdb/gdb/i387-tdep.c

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/* Intel 387 floating point stuff.
Copyright (C) 1988, 89, 91, 98, 99, 2000 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 "frame.h"
#include "inferior.h"
#include "language.h"
#include "value.h"
#include "gdbcore.h"
#include "floatformat.h"
/* FIXME: Eliminate the next two functions when we have the time to
change all the callers. */
void i387_to_double (char *from, char *to);
void double_to_i387 (char *from, char *to);
void
i387_to_double (from, to)
char *from;
char *to;
{
floatformat_to_double (&floatformat_i387_ext, from, (double *) to);
}
void
double_to_i387 (from, to)
char *from;
char *to;
{
floatformat_from_double (&floatformat_i387_ext, (double *) from, to);
}
/* FIXME: The functions on this page are used by the old `info float'
implementations that a few of the i386 targets provide. These
functions should be removed if all of these have been converted to
use the generic implementation based on the new register file
layout. */
static void print_387_control_bits (unsigned int control);
static void print_387_status_bits (unsigned int status);
static void
print_387_control_bits (control)
unsigned int control;
{
switch ((control >> 8) & 3)
{
case 0:
puts_unfiltered (" 24 bit; ");
break;
case 1:
puts_unfiltered (" (bad); ");
break;
case 2:
puts_unfiltered (" 53 bit; ");
break;
case 3:
puts_unfiltered (" 64 bit; ");
break;
}
switch ((control >> 10) & 3)
{
case 0:
puts_unfiltered ("NEAR; ");
break;
case 1:
puts_unfiltered ("DOWN; ");
break;
case 2:
puts_unfiltered ("UP; ");
break;
case 3:
puts_unfiltered ("CHOP; ");
break;
}
if (control & 0x3f)
{
puts_unfiltered ("mask");
if (control & 0x0001)
puts_unfiltered (" INVAL");
if (control & 0x0002)
puts_unfiltered (" DENOR");
if (control & 0x0004)
puts_unfiltered (" DIVZ");
if (control & 0x0008)
puts_unfiltered (" OVERF");
if (control & 0x0010)
puts_unfiltered (" UNDER");
if (control & 0x0020)
puts_unfiltered (" LOS");
puts_unfiltered (";");
}
if (control & 0xe080)
warning ("\nreserved bits on: %s",
local_hex_string (control & 0xe080));
}
void
print_387_control_word (control)
unsigned int control;
{
printf_filtered ("control %s:", local_hex_string(control & 0xffff));
print_387_control_bits (control);
puts_unfiltered ("\n");
}
static void
print_387_status_bits (status)
unsigned int status;
{
printf_unfiltered (" flags %d%d%d%d; ",
(status & 0x4000) != 0,
(status & 0x0400) != 0,
(status & 0x0200) != 0,
(status & 0x0100) != 0);
printf_unfiltered ("top %d; ", (status >> 11) & 7);
if (status & 0xff)
{
puts_unfiltered ("excep");
if (status & 0x0001) puts_unfiltered (" INVAL");
if (status & 0x0002) puts_unfiltered (" DENOR");
if (status & 0x0004) puts_unfiltered (" DIVZ");
if (status & 0x0008) puts_unfiltered (" OVERF");
if (status & 0x0010) puts_unfiltered (" UNDER");
if (status & 0x0020) puts_unfiltered (" LOS");
if (status & 0x0040) puts_unfiltered (" STACK");
}
}
void
print_387_status_word (status)
unsigned int status;
{
printf_filtered ("status %s:", local_hex_string (status & 0xffff));
print_387_status_bits (status);
puts_unfiltered ("\n");
}
/* Implement the `info float' layout based on the register definitions
in `tm-i386.h'. */
/* Print the floating point number specified by RAW. */
static void
print_i387_value (char *raw)
{
DOUBLEST value;
/* Avoid call to floatformat_to_doublest if possible to preserve as
much information as possible. */
#ifdef HAVE_LONG_DOUBLE
if (sizeof (value) == sizeof (long double)
&& HOST_LONG_DOUBLE_FORMAT == &floatformat_i387_ext)
{
/* Copy straight over, but take care of the padding. */
memcpy (&value, raw, FPU_REG_RAW_SIZE);
memset ((char *) &value + FPU_REG_RAW_SIZE, 0,
sizeof (value) - FPU_REG_RAW_SIZE);
}
else
#endif
floatformat_to_doublest (&floatformat_i387_ext, raw, &value);
/* 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
printf_filtered (" %-+27.19Lg", (long double) value);
#else
printf_filtered (" %-+27.19g", (double) value);
#endif
}
/* Print the classification for the register contents RAW. */
static void
print_i387_ext (unsigned char *raw)
{
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. */
printf_filtered (" %cInf", (sign ? '-' : '+'));
else if (sign && fraction[0] == 0x00000000 && fraction[1] == 0x40000000)
/* Real Indefinite (QNaN). */
puts_unfiltered (" Real Indefinite (QNaN)");
else if (fraction[1] & 0x40000000)
/* QNaN. */
puts_filtered (" QNaN");
else
/* SNaN. */
puts_filtered (" SNaN");
}
else if (exponent < 0x7fff && exponent > 0x0000 && integer)
/* Normal. */
print_i387_value (raw);
else if (exponent == 0x0000)
{
/* Denormal or zero. */
print_i387_value (raw);
if (integer)
/* Pseudo-denormal. */
puts_filtered (" Pseudo-denormal");
else if (fraction[0] || fraction[1])
/* Denormal. */
puts_filtered (" Denormal");
}
else
/* Unsupported. */
puts_filtered (" Unsupported");
}
/* Print the status word STATUS. */
static void
print_i387_status_word (unsigned int status)
{
printf_filtered ("Status Word: %s",
local_hex_string_custom (status, "04"));
puts_filtered (" ");
printf_filtered (" %s", (status & 0x0001) ? "IE" : " ");
printf_filtered (" %s", (status & 0x0002) ? "DE" : " ");
printf_filtered (" %s", (status & 0x0004) ? "ZE" : " ");
printf_filtered (" %s", (status & 0x0008) ? "OE" : " ");
printf_filtered (" %s", (status & 0x0010) ? "UE" : " ");
printf_filtered (" %s", (status & 0x0020) ? "PE" : " ");
puts_filtered (" ");
printf_filtered (" %s", (status & 0x0080) ? "ES" : " ");
puts_filtered (" ");
printf_filtered (" %s", (status & 0x0080) ? "SF" : " ");
puts_filtered (" ");
printf_filtered (" %s", (status & 0x0100) ? "C0" : " ");
printf_filtered (" %s", (status & 0x0200) ? "C1" : " ");
printf_filtered (" %s", (status & 0x0400) ? "C2" : " ");
printf_filtered (" %s", (status & 0x4000) ? "C3" : " ");
puts_filtered ("\n");
printf_filtered (" TOP: %d\n", ((status >> 11) & 7));
}
/* Print the control word CONTROL. */
static void
print_i387_control_word (unsigned int control)
{
printf_filtered ("Control Word: %s",
local_hex_string_custom (control, "04"));
puts_filtered (" ");
printf_filtered (" %s", (control & 0x0001) ? "IM" : " ");
printf_filtered (" %s", (control & 0x0002) ? "DM" : " ");
printf_filtered (" %s", (control & 0x0004) ? "ZM" : " ");
printf_filtered (" %s", (control & 0x0008) ? "OM" : " ");
printf_filtered (" %s", (control & 0x0010) ? "UM" : " ");
printf_filtered (" %s", (control & 0x0020) ? "PM" : " ");
puts_filtered ("\n");
puts_filtered (" PC: ");
switch ((control >> 8) & 3)
{
case 0:
puts_filtered ("Single Precision (24-bits)\n");
break;
case 1:
puts_filtered ("Reserved\n");
break;
case 2:
puts_filtered ("Double Precision (53-bits)\n");
break;
case 3:
puts_filtered ("Extended Precision (64-bits)\n");
break;
}
puts_filtered (" RC: ");
switch ((control >> 10) & 3)
{
case 0:
puts_filtered ("Round to nearest\n");
break;
case 1:
puts_filtered ("Round down\n");
break;
case 2:
puts_filtered ("Round up\n");
break;
case 3:
puts_filtered ("Round toward zero\n");
break;
}
}
/* Print out the i387 floating poin state. */
void
i387_float_info (void)
{
unsigned int fctrl;
unsigned int fstat;
unsigned int ftag;
unsigned int fiseg;
unsigned int fioff;
unsigned int foseg;
unsigned int fooff;
unsigned int fop;
int fpreg;
int top;
fctrl = read_register (FCTRL_REGNUM);
fstat = read_register (FSTAT_REGNUM);
ftag = read_register (FTAG_REGNUM);
fiseg = read_register (FCS_REGNUM);
fioff = read_register (FCOFF_REGNUM);
foseg = read_register (FDS_REGNUM);
fooff = read_register (FDOFF_REGNUM);
fop = read_register (FOP_REGNUM);
top = ((fstat >> 11) & 7);
for (fpreg = 7; fpreg >= 0; fpreg--)
{
unsigned char raw[FPU_REG_RAW_SIZE];
int tag = (ftag >> (fpreg * 2)) & 3;
int i;
printf_filtered ("%sR%d: ", fpreg == top ? "=>" : " ", fpreg);
switch (tag)
{
case 0:
puts_filtered ("Valid ");
break;
case 1:
puts_filtered ("Zero ");
break;
case 2:
puts_filtered ("Special ");
break;
case 3:
puts_filtered ("Empty ");
break;
}
read_register_gen ((fpreg + 8 - top) % 8 + FP0_REGNUM, raw);
puts_filtered ("0x");
for (i = 9; i >= 0; i--)
printf_filtered ("%02x", raw[i]);
if (tag != 3)
print_i387_ext (raw);
puts_filtered ("\n");
}
puts_filtered ("\n");
print_i387_status_word (fstat);
print_i387_control_word (fctrl);
printf_filtered ("Tag Word: %s\n",
local_hex_string_custom (ftag, "04"));
printf_filtered ("Instruction Pointer: %s:",
local_hex_string_custom (fiseg, "02"));
printf_filtered ("%s\n", local_hex_string_custom (fioff, "08"));
printf_filtered ("Operand Pointer: %s:",
local_hex_string_custom (foseg, "02"));
printf_filtered ("%s\n", local_hex_string_custom (fooff, "08"));
printf_filtered ("Opcode: %s\n",
local_hex_string_custom (fop ? (fop | 0xd800) : 0, "04"));
}