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720 lines
20 KiB
C
720 lines
20 KiB
C
/* Intel 387 floating point stuff.
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Copyright 1988, 1989, 1991, 1992, 1993, 1994, 1998, 1999, 2000,
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2001, 2002 Free Software Foundation, Inc.
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This file is part of GDB.
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This program is free software; you can redistribute it and/or modify
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it under the terms of the GNU General Public License as published by
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the Free Software Foundation; either version 2 of the License, or
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(at your option) any later version.
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This program is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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GNU General Public License for more details.
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You should have received a copy of the GNU General Public License
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along with this program; if not, write to the Free Software
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Foundation, Inc., 59 Temple Place - Suite 330,
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Boston, MA 02111-1307, USA. */
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#include "defs.h"
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#include "frame.h"
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#include "inferior.h"
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#include "language.h"
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#include "value.h"
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#include "gdbcore.h"
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#include "floatformat.h"
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#include "regcache.h"
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#include "gdb_assert.h"
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#include "gdb_string.h"
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#include "doublest.h"
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#include "i386-tdep.h"
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/* FIXME: Eliminate the next two functions when we have the time to
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change all the callers. */
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void i387_to_double (char *from, char *to);
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void double_to_i387 (char *from, char *to);
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void
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i387_to_double (char *from, char *to)
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{
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floatformat_to_double (&floatformat_i387_ext, from, (double *) to);
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}
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void
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double_to_i387 (char *from, char *to)
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{
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floatformat_from_double (&floatformat_i387_ext, (double *) from, to);
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}
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/* FIXME: The functions on this page are used by the old `info float'
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implementations that a few of the i386 targets provide. These
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functions should be removed if all of these have been converted to
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use the generic implementation based on the new register file
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layout. */
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static void print_387_control_bits (unsigned int control);
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static void print_387_status_bits (unsigned int status);
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static void
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print_387_control_bits (unsigned int control)
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{
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switch ((control >> 8) & 3)
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{
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case 0:
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puts_unfiltered (" 24 bit; ");
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break;
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case 1:
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puts_unfiltered (" (bad); ");
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break;
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case 2:
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puts_unfiltered (" 53 bit; ");
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break;
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case 3:
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puts_unfiltered (" 64 bit; ");
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break;
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}
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switch ((control >> 10) & 3)
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{
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case 0:
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puts_unfiltered ("NEAR; ");
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break;
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case 1:
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puts_unfiltered ("DOWN; ");
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break;
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case 2:
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puts_unfiltered ("UP; ");
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break;
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case 3:
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puts_unfiltered ("CHOP; ");
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break;
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}
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if (control & 0x3f)
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{
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puts_unfiltered ("mask");
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if (control & 0x0001)
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puts_unfiltered (" INVAL");
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if (control & 0x0002)
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puts_unfiltered (" DENOR");
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if (control & 0x0004)
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puts_unfiltered (" DIVZ");
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if (control & 0x0008)
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puts_unfiltered (" OVERF");
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if (control & 0x0010)
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puts_unfiltered (" UNDER");
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if (control & 0x0020)
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puts_unfiltered (" LOS");
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puts_unfiltered (";");
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}
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if (control & 0xe080)
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warning ("\nreserved bits on: %s",
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local_hex_string (control & 0xe080));
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}
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void
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print_387_control_word (unsigned int control)
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{
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printf_filtered ("control %s:", local_hex_string(control & 0xffff));
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print_387_control_bits (control);
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puts_unfiltered ("\n");
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}
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static void
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print_387_status_bits (unsigned int status)
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{
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printf_unfiltered (" flags %d%d%d%d; ",
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(status & 0x4000) != 0,
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(status & 0x0400) != 0,
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(status & 0x0200) != 0,
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(status & 0x0100) != 0);
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printf_unfiltered ("top %d; ", (status >> 11) & 7);
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if (status & 0xff)
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{
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puts_unfiltered ("excep");
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if (status & 0x0001) puts_unfiltered (" INVAL");
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if (status & 0x0002) puts_unfiltered (" DENOR");
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if (status & 0x0004) puts_unfiltered (" DIVZ");
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if (status & 0x0008) puts_unfiltered (" OVERF");
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if (status & 0x0010) puts_unfiltered (" UNDER");
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if (status & 0x0020) puts_unfiltered (" LOS");
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if (status & 0x0040) puts_unfiltered (" STACK");
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}
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}
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void
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print_387_status_word (unsigned int status)
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{
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printf_filtered ("status %s:", local_hex_string (status & 0xffff));
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print_387_status_bits (status);
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puts_unfiltered ("\n");
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}
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/* Implement the `info float' layout based on the register definitions
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in `tm-i386.h'. */
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/* Print the floating point number specified by RAW. */
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static void
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print_i387_value (char *raw, struct ui_file *file)
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{
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DOUBLEST value;
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/* Using extract_typed_floating here might affect the representation
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of certain numbers such as NaNs, even if GDB is running natively.
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This is fine since our caller already detects such special
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numbers and we print the hexadecimal representation anyway. */
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value = extract_typed_floating (raw, builtin_type_i387_ext);
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/* We try to print 19 digits. The last digit may or may not contain
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garbage, but we'd better print one too many. We need enough room
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to print the value, 1 position for the sign, 1 for the decimal
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point, 19 for the digits and 6 for the exponent adds up to 27. */
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#ifdef PRINTF_HAS_LONG_DOUBLE
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fprintf_filtered (file, " %-+27.19Lg", (long double) value);
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#else
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fprintf_filtered (file, " %-+27.19g", (double) value);
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#endif
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}
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/* Print the classification for the register contents RAW. */
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static void
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print_i387_ext (unsigned char *raw, struct ui_file *file)
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{
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int sign;
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int integer;
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unsigned int exponent;
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unsigned long fraction[2];
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sign = raw[9] & 0x80;
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integer = raw[7] & 0x80;
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exponent = (((raw[9] & 0x7f) << 8) | raw[8]);
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fraction[0] = ((raw[3] << 24) | (raw[2] << 16) | (raw[1] << 8) | raw[0]);
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fraction[1] = (((raw[7] & 0x7f) << 24) | (raw[6] << 16)
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| (raw[5] << 8) | raw[4]);
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if (exponent == 0x7fff && integer)
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{
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if (fraction[0] == 0x00000000 && fraction[1] == 0x00000000)
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/* Infinity. */
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fprintf_filtered (file, " %cInf", (sign ? '-' : '+'));
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else if (sign && fraction[0] == 0x00000000 && fraction[1] == 0x40000000)
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/* Real Indefinite (QNaN). */
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fputs_unfiltered (" Real Indefinite (QNaN)", file);
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else if (fraction[1] & 0x40000000)
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/* QNaN. */
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fputs_filtered (" QNaN", file);
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else
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/* SNaN. */
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fputs_filtered (" SNaN", file);
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}
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else if (exponent < 0x7fff && exponent > 0x0000 && integer)
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/* Normal. */
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print_i387_value (raw, file);
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else if (exponent == 0x0000)
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{
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/* Denormal or zero. */
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print_i387_value (raw, file);
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if (integer)
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/* Pseudo-denormal. */
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fputs_filtered (" Pseudo-denormal", file);
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else if (fraction[0] || fraction[1])
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/* Denormal. */
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fputs_filtered (" Denormal", file);
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}
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else
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/* Unsupported. */
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fputs_filtered (" Unsupported", file);
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}
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/* Print the status word STATUS. */
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static void
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print_i387_status_word (unsigned int status, struct ui_file *file)
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{
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fprintf_filtered (file, "Status Word: %s",
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local_hex_string_custom (status, "04"));
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fputs_filtered (" ", file);
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fprintf_filtered (file, " %s", (status & 0x0001) ? "IE" : " ");
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fprintf_filtered (file, " %s", (status & 0x0002) ? "DE" : " ");
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fprintf_filtered (file, " %s", (status & 0x0004) ? "ZE" : " ");
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fprintf_filtered (file, " %s", (status & 0x0008) ? "OE" : " ");
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fprintf_filtered (file, " %s", (status & 0x0010) ? "UE" : " ");
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fprintf_filtered (file, " %s", (status & 0x0020) ? "PE" : " ");
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fputs_filtered (" ", file);
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fprintf_filtered (file, " %s", (status & 0x0080) ? "ES" : " ");
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fputs_filtered (" ", file);
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fprintf_filtered (file, " %s", (status & 0x0040) ? "SF" : " ");
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fputs_filtered (" ", file);
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fprintf_filtered (file, " %s", (status & 0x0100) ? "C0" : " ");
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fprintf_filtered (file, " %s", (status & 0x0200) ? "C1" : " ");
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fprintf_filtered (file, " %s", (status & 0x0400) ? "C2" : " ");
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fprintf_filtered (file, " %s", (status & 0x4000) ? "C3" : " ");
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fputs_filtered ("\n", file);
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fprintf_filtered (file,
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" TOP: %d\n", ((status >> 11) & 7));
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}
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/* Print the control word CONTROL. */
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static void
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print_i387_control_word (unsigned int control, struct ui_file *file)
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{
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fprintf_filtered (file, "Control Word: %s",
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local_hex_string_custom (control, "04"));
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fputs_filtered (" ", file);
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fprintf_filtered (file, " %s", (control & 0x0001) ? "IM" : " ");
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fprintf_filtered (file, " %s", (control & 0x0002) ? "DM" : " ");
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fprintf_filtered (file, " %s", (control & 0x0004) ? "ZM" : " ");
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fprintf_filtered (file, " %s", (control & 0x0008) ? "OM" : " ");
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fprintf_filtered (file, " %s", (control & 0x0010) ? "UM" : " ");
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fprintf_filtered (file, " %s", (control & 0x0020) ? "PM" : " ");
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fputs_filtered ("\n", file);
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fputs_filtered (" PC: ", file);
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switch ((control >> 8) & 3)
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{
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case 0:
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fputs_filtered ("Single Precision (24-bits)\n", file);
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break;
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case 1:
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fputs_filtered ("Reserved\n", file);
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break;
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case 2:
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fputs_filtered ("Double Precision (53-bits)\n", file);
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break;
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case 3:
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fputs_filtered ("Extended Precision (64-bits)\n", file);
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break;
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}
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fputs_filtered (" RC: ", file);
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switch ((control >> 10) & 3)
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{
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case 0:
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fputs_filtered ("Round to nearest\n", file);
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break;
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case 1:
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fputs_filtered ("Round down\n", file);
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break;
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case 2:
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fputs_filtered ("Round up\n", file);
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break;
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case 3:
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fputs_filtered ("Round toward zero\n", file);
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break;
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}
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}
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/* Print out the i387 floating point state. Note that we ignore FRAME
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in the code below. That's OK since floating-point registers are
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never saved on the stack. */
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void
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i387_print_float_info (struct gdbarch *gdbarch, struct ui_file *file,
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struct frame_info *frame, const char *args)
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{
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char buf[4];
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ULONGEST fctrl;
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ULONGEST fstat;
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ULONGEST ftag;
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ULONGEST fiseg;
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ULONGEST fioff;
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ULONGEST foseg;
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ULONGEST fooff;
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ULONGEST fop;
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int fpreg;
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int top;
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frame_register_read (frame, FCTRL_REGNUM, buf);
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fctrl = extract_unsigned_integer (buf, 4);
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frame_register_read (frame, FSTAT_REGNUM, buf);
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fstat = extract_unsigned_integer (buf, 4);
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frame_register_read (frame, FTAG_REGNUM, buf);
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ftag = extract_unsigned_integer (buf, 4);
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frame_register_read (frame, FISEG_REGNUM, buf);
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fiseg = extract_unsigned_integer (buf, 4);
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frame_register_read (frame, FIOFF_REGNUM, buf);
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fioff = extract_unsigned_integer (buf, 4);
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frame_register_read (frame, FOSEG_REGNUM, buf);
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foseg = extract_unsigned_integer (buf, 4);
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frame_register_read (frame, FOOFF_REGNUM, buf);
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fooff = extract_unsigned_integer (buf, 4);
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frame_register_read (frame, FOP_REGNUM, buf);
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fop = extract_unsigned_integer (buf, 4);
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top = ((fstat >> 11) & 7);
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for (fpreg = 7; fpreg >= 0; fpreg--)
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{
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unsigned char raw[FPU_REG_RAW_SIZE];
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int tag = (ftag >> (fpreg * 2)) & 3;
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int i;
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fprintf_filtered (file, "%sR%d: ", fpreg == top ? "=>" : " ", fpreg);
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switch (tag)
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{
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case 0:
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fputs_filtered ("Valid ", file);
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break;
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case 1:
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fputs_filtered ("Zero ", file);
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break;
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case 2:
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fputs_filtered ("Special ", file);
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break;
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case 3:
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fputs_filtered ("Empty ", file);
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break;
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}
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frame_register_read (frame, (fpreg + 8 - top) % 8 + FP0_REGNUM, raw);
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fputs_filtered ("0x", file);
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for (i = 9; i >= 0; i--)
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fprintf_filtered (file, "%02x", raw[i]);
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if (tag != 3)
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print_i387_ext (raw, file);
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fputs_filtered ("\n", file);
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}
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fputs_filtered ("\n", file);
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print_i387_status_word (fstat, file);
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print_i387_control_word (fctrl, file);
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fprintf_filtered (file, "Tag Word: %s\n",
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local_hex_string_custom (ftag, "04"));
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fprintf_filtered (file, "Instruction Pointer: %s:",
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local_hex_string_custom (fiseg, "02"));
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fprintf_filtered (file, "%s\n", local_hex_string_custom (fioff, "08"));
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fprintf_filtered (file, "Operand Pointer: %s:",
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local_hex_string_custom (foseg, "02"));
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fprintf_filtered (file, "%s\n", local_hex_string_custom (fooff, "08"));
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fprintf_filtered (file, "Opcode: %s\n",
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local_hex_string_custom (fop ? (fop | 0xd800) : 0, "04"));
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}
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/* FIXME: kettenis/2000-05-21: Right now more than a few i386 targets
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define their own routines to manage the floating-point registers in
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GDB's register array. Most (if not all) of these targets use the
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format used by the "fsave" instruction in their communication with
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the OS. They should all be converted to use the routines below. */
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/* At fsave_offset[REGNUM] you'll find the offset to the location in
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the data structure used by the "fsave" instruction where GDB
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register REGNUM is stored. */
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static int fsave_offset[] =
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{
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28 + 0 * FPU_REG_RAW_SIZE, /* FP0_REGNUM through ... */
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28 + 1 * FPU_REG_RAW_SIZE,
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28 + 2 * FPU_REG_RAW_SIZE,
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28 + 3 * FPU_REG_RAW_SIZE,
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28 + 4 * FPU_REG_RAW_SIZE,
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28 + 5 * FPU_REG_RAW_SIZE,
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28 + 6 * FPU_REG_RAW_SIZE,
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28 + 7 * FPU_REG_RAW_SIZE, /* ... FP7_REGNUM. */
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0, /* FCTRL_REGNUM (16 bits). */
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4, /* FSTAT_REGNUM (16 bits). */
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8, /* FTAG_REGNUM (16 bits). */
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16, /* FISEG_REGNUM (16 bits). */
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12, /* FIOFF_REGNUM. */
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24, /* FOSEG_REGNUM. */
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20, /* FOOFF_REGNUM. */
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18 /* FOP_REGNUM (bottom 11 bits). */
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};
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#define FSAVE_ADDR(fsave, regnum) (fsave + fsave_offset[regnum - FP0_REGNUM])
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/* Fill register REGNUM in GDB's register array with the appropriate
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value from *FSAVE. This function masks off any of the reserved
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bits in *FSAVE. */
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void
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i387_supply_register (int regnum, char *fsave)
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{
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/* Most of the FPU control registers occupy only 16 bits in
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the fsave area. Give those a special treatment. */
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if (regnum >= FPC_REGNUM
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&& regnum != FIOFF_REGNUM && regnum != FOOFF_REGNUM)
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{
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unsigned char val[4];
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memcpy (val, FSAVE_ADDR (fsave, regnum), 2);
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val[2] = val[3] = 0;
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if (regnum == FOP_REGNUM)
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val[1] &= ((1 << 3) - 1);
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supply_register (regnum, val);
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}
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else
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supply_register (regnum, FSAVE_ADDR (fsave, regnum));
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}
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/* Fill GDB's register array with the floating-point register values
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in *FSAVE. This function masks off any of the reserved
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bits in *FSAVE. */
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void
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i387_supply_fsave (char *fsave)
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{
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int i;
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for (i = FP0_REGNUM; i < XMM0_REGNUM; i++)
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i387_supply_register (i, fsave);
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}
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/* Fill register REGNUM (if it is a floating-point register) in *FSAVE
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with the value in GDB's register array. If REGNUM is -1, do this
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for all registers. This function doesn't touch any of the reserved
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bits in *FSAVE. */
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void
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i387_fill_fsave (char *fsave, int regnum)
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{
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||
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));
|
||
}
|
||
}
|
||
|
||
|
||
/* 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);
|
||
|
||
|
||
/* 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, last_regnum = MXCSR_REGNUM;
|
||
|
||
if (gdbarch_tdep (current_gdbarch)->num_xmm_regs == 0)
|
||
last_regnum = FOP_REGNUM;
|
||
|
||
for (i = FP0_REGNUM; i <= last_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, last_regnum = MXCSR_REGNUM;
|
||
|
||
if (gdbarch_tdep (current_gdbarch)->num_xmm_regs == 0)
|
||
last_regnum = FOP_REGNUM;
|
||
|
||
for (i = FP0_REGNUM; i <= last_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);
|
||
}
|
||
}
|
||
}
|