1 /* Intel 387 floating point stuff.
3 Copyright 1988, 1989, 1991, 1992, 1993, 1994, 1998, 1999, 2000,
4 2001, 2002, 2003 Free Software Foundation, Inc.
6 This file is part of GDB.
8 This program is free software; you can redistribute it and/or modify
9 it under the terms of the GNU General Public License as published by
10 the Free Software Foundation; either version 2 of the License, or
11 (at your option) any later version.
13 This program is distributed in the hope that it will be useful,
14 but WITHOUT ANY WARRANTY; without even the implied warranty of
15 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
16 GNU General Public License for more details.
18 You should have received a copy of the GNU General Public License
19 along with this program; if not, write to the Free Software
20 Foundation, Inc., 59 Temple Place - Suite 330,
21 Boston, MA 02111-1307, USA. */
25 #include "floatformat.h"
33 #include "gdb_assert.h"
34 #include "gdb_string.h"
36 #include "i386-tdep.h"
37 #include "i387-tdep.h"
39 /* Implement the `info float' layout based on the register definitions
42 /* Print the floating point number specified by RAW. */
45 print_i387_value (char *raw
, struct ui_file
*file
)
49 /* Using extract_typed_floating here might affect the representation
50 of certain numbers such as NaNs, even if GDB is running natively.
51 This is fine since our caller already detects such special
52 numbers and we print the hexadecimal representation anyway. */
53 value
= extract_typed_floating (raw
, builtin_type_i387_ext
);
55 /* We try to print 19 digits. The last digit may or may not contain
56 garbage, but we'd better print one too many. We need enough room
57 to print the value, 1 position for the sign, 1 for the decimal
58 point, 19 for the digits and 6 for the exponent adds up to 27. */
59 #ifdef PRINTF_HAS_LONG_DOUBLE
60 fprintf_filtered (file
, " %-+27.19Lg", (long double) value
);
62 fprintf_filtered (file
, " %-+27.19g", (double) value
);
66 /* Print the classification for the register contents RAW. */
69 print_i387_ext (unsigned char *raw
, struct ui_file
*file
)
73 unsigned int exponent
;
74 unsigned long fraction
[2];
77 integer
= raw
[7] & 0x80;
78 exponent
= (((raw
[9] & 0x7f) << 8) | raw
[8]);
79 fraction
[0] = ((raw
[3] << 24) | (raw
[2] << 16) | (raw
[1] << 8) | raw
[0]);
80 fraction
[1] = (((raw
[7] & 0x7f) << 24) | (raw
[6] << 16)
81 | (raw
[5] << 8) | raw
[4]);
83 if (exponent
== 0x7fff && integer
)
85 if (fraction
[0] == 0x00000000 && fraction
[1] == 0x00000000)
87 fprintf_filtered (file
, " %cInf", (sign
? '-' : '+'));
88 else if (sign
&& fraction
[0] == 0x00000000 && fraction
[1] == 0x40000000)
89 /* Real Indefinite (QNaN). */
90 fputs_unfiltered (" Real Indefinite (QNaN)", file
);
91 else if (fraction
[1] & 0x40000000)
93 fputs_filtered (" QNaN", file
);
96 fputs_filtered (" SNaN", file
);
98 else if (exponent
< 0x7fff && exponent
> 0x0000 && integer
)
100 print_i387_value (raw
, file
);
101 else if (exponent
== 0x0000)
103 /* Denormal or zero. */
104 print_i387_value (raw
, file
);
107 /* Pseudo-denormal. */
108 fputs_filtered (" Pseudo-denormal", file
);
109 else if (fraction
[0] || fraction
[1])
111 fputs_filtered (" Denormal", file
);
115 fputs_filtered (" Unsupported", file
);
118 /* Print the status word STATUS. */
121 print_i387_status_word (unsigned int status
, struct ui_file
*file
)
123 fprintf_filtered (file
, "Status Word: %s",
124 local_hex_string_custom (status
, "04"));
125 fputs_filtered (" ", file
);
126 fprintf_filtered (file
, " %s", (status
& 0x0001) ? "IE" : " ");
127 fprintf_filtered (file
, " %s", (status
& 0x0002) ? "DE" : " ");
128 fprintf_filtered (file
, " %s", (status
& 0x0004) ? "ZE" : " ");
129 fprintf_filtered (file
, " %s", (status
& 0x0008) ? "OE" : " ");
130 fprintf_filtered (file
, " %s", (status
& 0x0010) ? "UE" : " ");
131 fprintf_filtered (file
, " %s", (status
& 0x0020) ? "PE" : " ");
132 fputs_filtered (" ", file
);
133 fprintf_filtered (file
, " %s", (status
& 0x0080) ? "ES" : " ");
134 fputs_filtered (" ", file
);
135 fprintf_filtered (file
, " %s", (status
& 0x0040) ? "SF" : " ");
136 fputs_filtered (" ", file
);
137 fprintf_filtered (file
, " %s", (status
& 0x0100) ? "C0" : " ");
138 fprintf_filtered (file
, " %s", (status
& 0x0200) ? "C1" : " ");
139 fprintf_filtered (file
, " %s", (status
& 0x0400) ? "C2" : " ");
140 fprintf_filtered (file
, " %s", (status
& 0x4000) ? "C3" : " ");
142 fputs_filtered ("\n", file
);
144 fprintf_filtered (file
,
145 " TOP: %d\n", ((status
>> 11) & 7));
148 /* Print the control word CONTROL. */
151 print_i387_control_word (unsigned int control
, struct ui_file
*file
)
153 fprintf_filtered (file
, "Control Word: %s",
154 local_hex_string_custom (control
, "04"));
155 fputs_filtered (" ", file
);
156 fprintf_filtered (file
, " %s", (control
& 0x0001) ? "IM" : " ");
157 fprintf_filtered (file
, " %s", (control
& 0x0002) ? "DM" : " ");
158 fprintf_filtered (file
, " %s", (control
& 0x0004) ? "ZM" : " ");
159 fprintf_filtered (file
, " %s", (control
& 0x0008) ? "OM" : " ");
160 fprintf_filtered (file
, " %s", (control
& 0x0010) ? "UM" : " ");
161 fprintf_filtered (file
, " %s", (control
& 0x0020) ? "PM" : " ");
163 fputs_filtered ("\n", file
);
165 fputs_filtered (" PC: ", file
);
166 switch ((control
>> 8) & 3)
169 fputs_filtered ("Single Precision (24-bits)\n", file
);
172 fputs_filtered ("Reserved\n", file
);
175 fputs_filtered ("Double Precision (53-bits)\n", file
);
178 fputs_filtered ("Extended Precision (64-bits)\n", file
);
182 fputs_filtered (" RC: ", file
);
183 switch ((control
>> 10) & 3)
186 fputs_filtered ("Round to nearest\n", file
);
189 fputs_filtered ("Round down\n", file
);
192 fputs_filtered ("Round up\n", file
);
195 fputs_filtered ("Round toward zero\n", file
);
200 /* Print out the i387 floating point state. Note that we ignore FRAME
201 in the code below. That's OK since floating-point registers are
202 never saved on the stack. */
205 i387_print_float_info (struct gdbarch
*gdbarch
, struct ui_file
*file
,
206 struct frame_info
*frame
, const char *args
)
208 struct gdbarch_tdep
*tdep
= gdbarch_tdep (get_frame_arch (frame
));
221 gdb_assert (gdbarch
== get_frame_arch (frame
));
223 /* Define I387_ST0_REGNUM such that we use the proper definitions
224 for FRAME's architecture. */
225 #define I387_ST0_REGNUM tdep->st0_regnum
227 fctrl
= get_frame_register_unsigned (frame
, I387_FCTRL_REGNUM
);
228 fstat
= get_frame_register_unsigned (frame
, I387_FSTAT_REGNUM
);
229 ftag
= get_frame_register_unsigned (frame
, I387_FTAG_REGNUM
);
230 fiseg
= get_frame_register_unsigned (frame
, I387_FISEG_REGNUM
);
231 fioff
= get_frame_register_unsigned (frame
, I387_FIOFF_REGNUM
);
232 foseg
= get_frame_register_unsigned (frame
, I387_FOSEG_REGNUM
);
233 fooff
= get_frame_register_unsigned (frame
, I387_FOOFF_REGNUM
);
234 fop
= get_frame_register_unsigned (frame
, I387_FOP_REGNUM
);
236 top
= ((fstat
>> 11) & 7);
238 for (fpreg
= 7; fpreg
>= 0; fpreg
--)
240 unsigned char raw
[I386_MAX_REGISTER_SIZE
];
241 int tag
= (ftag
>> (fpreg
* 2)) & 3;
244 fprintf_filtered (file
, "%sR%d: ", fpreg
== top
? "=>" : " ", fpreg
);
249 fputs_filtered ("Valid ", file
);
252 fputs_filtered ("Zero ", file
);
255 fputs_filtered ("Special ", file
);
258 fputs_filtered ("Empty ", file
);
262 get_frame_register (frame
, (fpreg
+ 8 - top
) % 8 + I387_ST0_REGNUM
, raw
);
264 fputs_filtered ("0x", file
);
265 for (i
= 9; i
>= 0; i
--)
266 fprintf_filtered (file
, "%02x", raw
[i
]);
269 print_i387_ext (raw
, file
);
271 fputs_filtered ("\n", file
);
274 fputs_filtered ("\n", file
);
276 print_i387_status_word (fstat
, file
);
277 print_i387_control_word (fctrl
, file
);
278 fprintf_filtered (file
, "Tag Word: %s\n",
279 local_hex_string_custom (ftag
, "04"));
280 fprintf_filtered (file
, "Instruction Pointer: %s:",
281 local_hex_string_custom (fiseg
, "02"));
282 fprintf_filtered (file
, "%s\n", local_hex_string_custom (fioff
, "08"));
283 fprintf_filtered (file
, "Operand Pointer: %s:",
284 local_hex_string_custom (foseg
, "02"));
285 fprintf_filtered (file
, "%s\n", local_hex_string_custom (fooff
, "08"));
286 fprintf_filtered (file
, "Opcode: %s\n",
287 local_hex_string_custom (fop
? (fop
| 0xd800) : 0, "04"));
289 #undef I387_ST0_REGNUM
293 /* Read a value of type TYPE from register REGNUM in frame FRAME, and
294 return its contents in TO. */
297 i387_register_to_value (struct frame_info
*frame
, int regnum
,
298 struct type
*type
, void *to
)
300 char from
[I386_MAX_REGISTER_SIZE
];
302 gdb_assert (i386_fp_regnum_p (regnum
));
304 /* We only support floating-point values. */
305 if (TYPE_CODE (type
) != TYPE_CODE_FLT
)
307 warning ("Cannot convert floating-point register value "
308 "to non-floating-point type.");
312 /* Convert to TYPE. This should be a no-op if TYPE is equivalent to
313 the extended floating-point format used by the FPU. */
314 get_frame_register (frame
, regnum
, from
);
315 convert_typed_floating (from
, builtin_type_i387_ext
, to
, type
);
318 /* Write the contents FROM of a value of type TYPE into register
319 REGNUM in frame FRAME. */
322 i387_value_to_register (struct frame_info
*frame
, int regnum
,
323 struct type
*type
, const void *from
)
325 char to
[I386_MAX_REGISTER_SIZE
];
327 gdb_assert (i386_fp_regnum_p (regnum
));
329 /* We only support floating-point values. */
330 if (TYPE_CODE (type
) != TYPE_CODE_FLT
)
332 warning ("Cannot convert non-floating-point type "
333 "to floating-point register value.");
337 /* Convert from TYPE. This should be a no-op if TYPE is equivalent
338 to the extended floating-point format used by the FPU. */
339 convert_typed_floating (from
, type
, to
, builtin_type_i387_ext
);
340 put_frame_register (frame
, regnum
, to
);
345 /* Handle FSAVE and FXSAVE formats. */
347 /* FIXME: kettenis/20030927: The functions below should accept a
348 `regcache' argument, but I don't want to change the function
349 signature just yet. There's some band-aid in the functions below
350 in the form of the `regcache' local variables. This will ease the
351 transition later on. */
353 /* At fsave_offset[REGNUM] you'll find the offset to the location in
354 the data structure used by the "fsave" instruction where GDB
355 register REGNUM is stored. */
357 static int fsave_offset
[] =
359 28 + 0 * 10, /* %st(0) ... */
366 28 + 7 * 10, /* ... %st(7). */
367 0, /* `fctrl' (16 bits). */
368 4, /* `fstat' (16 bits). */
369 8, /* `ftag' (16 bits). */
370 16, /* `fiseg' (16 bits). */
372 24, /* `foseg' (16 bits). */
374 18 /* `fop' (bottom 11 bits). */
377 #define FSAVE_ADDR(fsave, regnum) \
378 (fsave + fsave_offset[regnum - I387_ST0_REGNUM])
381 /* Fill register REGNUM in REGCACHE with the appropriate value from
382 *FSAVE. This function masks off any of the reserved bits in
386 i387_supply_fsave (struct regcache
*regcache
, int regnum
, const void *fsave
)
388 struct gdbarch_tdep
*tdep
= gdbarch_tdep (get_regcache_arch (regcache
));
389 const char *regs
= fsave
;
392 gdb_assert (tdep
->st0_regnum
>= I386_ST0_REGNUM
);
394 /* Define I387_ST0_REGNUM such that we use the proper definitions
395 for REGCACHE's architecture. */
396 #define I387_ST0_REGNUM tdep->st0_regnum
398 for (i
= I387_ST0_REGNUM
; i
< I387_XMM0_REGNUM
; i
++)
399 if (regnum
== -1 || regnum
== i
)
403 regcache_raw_supply (regcache
, i
, NULL
);
407 /* Most of the FPU control registers occupy only 16 bits in the
408 fsave area. Give those a special treatment. */
409 if (i
>= I387_FCTRL_REGNUM
410 && i
!= I387_FIOFF_REGNUM
&& i
!= I387_FOOFF_REGNUM
)
412 unsigned char val
[4];
414 memcpy (val
, FSAVE_ADDR (regs
, i
), 2);
416 if (i
== I387_FOP_REGNUM
)
417 val
[1] &= ((1 << 3) - 1);
418 regcache_raw_supply (regcache
, i
, val
);
421 regcache_raw_supply (regcache
, i
, FSAVE_ADDR (regs
, i
));
423 #undef I387_ST0_REGNUM
426 /* Fill register REGNUM (if it is a floating-point register) in *FSAVE
427 with the value in GDB's register cache. If REGNUM is -1, do this
428 for all registers. This function doesn't touch any of the reserved
432 i387_fill_fsave (void *fsave
, int regnum
)
434 struct regcache
*regcache
= current_regcache
;
435 struct gdbarch_tdep
*tdep
= gdbarch_tdep (current_gdbarch
);
439 gdb_assert (tdep
->st0_regnum
>= I386_ST0_REGNUM
);
441 /* Define I387_ST0_REGNUM such that we use the proper definitions
442 for REGCACHE's architecture. */
443 #define I387_ST0_REGNUM tdep->st0_regnum
445 for (i
= I387_ST0_REGNUM
; i
< I387_XMM0_REGNUM
; i
++)
446 if (regnum
== -1 || regnum
== i
)
448 /* Most of the FPU control registers occupy only 16 bits in
449 the fsave area. Give those a special treatment. */
450 if (i
>= I387_FCTRL_REGNUM
451 && i
!= I387_FIOFF_REGNUM
&& i
!= I387_FOOFF_REGNUM
)
453 unsigned char buf
[4];
455 regcache_raw_collect (regcache
, i
, buf
);
457 if (i
== I387_FOP_REGNUM
)
459 /* The opcode occupies only 11 bits. Make sure we
460 don't touch the other bits. */
461 buf
[1] &= ((1 << 3) - 1);
462 buf
[1] |= ((FSAVE_ADDR (regs
, i
))[1] & ~((1 << 3) - 1));
464 memcpy (FSAVE_ADDR (regs
, i
), buf
, 2);
467 regcache_raw_collect (regcache
, i
, FSAVE_ADDR (regs
, i
));
469 #undef I387_ST0_REGNUM
473 /* At fxsave_offset[REGNUM] you'll find the offset to the location in
474 the data structure used by the "fxsave" instruction where GDB
475 register REGNUM is stored. */
477 static int fxsave_offset
[] =
479 32, /* %st(0) through ... */
486 144, /* ... %st(7) (80 bits each). */
487 0, /* `fctrl' (16 bits). */
488 2, /* `fstat' (16 bits). */
489 4, /* `ftag' (16 bits). */
490 12, /* `fiseg' (16 bits). */
492 20, /* `foseg' (16 bits). */
494 6, /* `fop' (bottom 11 bits). */
495 160 + 0 * 16, /* %xmm0 through ... */
510 160 + 15 * 16, /* ... %xmm15 (128 bits each). */
513 #define FXSAVE_ADDR(fxsave, regnum) \
514 (fxsave + fxsave_offset[regnum - I387_ST0_REGNUM])
516 /* We made an unfortunate choice in putting %mxcsr after the SSE
517 registers %xmm0-%xmm7 instead of before, since it makes supporting
518 the registers %xmm8-%xmm15 on AMD64 a bit involved. Therefore we
519 don't include the offset for %mxcsr here above. */
521 #define FXSAVE_MXCSR_ADDR(fxsave) (fxsave + 24)
523 static int i387_tag (const unsigned char *raw
);
526 /* Fill register REGNUM in REGCACHE with the appropriate
527 floating-point or SSE register value from *FXSAVE. This function
528 masks off any of the reserved bits in *FXSAVE. */
531 i387_supply_fxsave (struct regcache
*regcache
, int regnum
, const void *fxsave
)
533 struct gdbarch_tdep
*tdep
= gdbarch_tdep (get_regcache_arch (regcache
));
534 const char *regs
= fxsave
;
537 gdb_assert (tdep
->st0_regnum
>= I386_ST0_REGNUM
);
538 gdb_assert (tdep
->num_xmm_regs
> 0);
540 /* Define I387_ST0_REGNUM and I387_NUM_XMM_REGS such that we use the
541 proper definitions for REGCACHE's architecture. */
543 #define I387_ST0_REGNUM tdep->st0_regnum
544 #define I387_NUM_XMM_REGS tdep->num_xmm_regs
546 for (i
= I387_ST0_REGNUM
; i
< I387_MXCSR_REGNUM
; i
++)
547 if (regnum
== -1 || regnum
== i
)
551 regcache_raw_supply (regcache
, i
, NULL
);
555 /* Most of the FPU control registers occupy only 16 bits in
556 the fxsave area. Give those a special treatment. */
557 if (i
>= I387_FCTRL_REGNUM
&& i
< I387_XMM0_REGNUM
558 && i
!= I387_FIOFF_REGNUM
&& i
!= I387_FOOFF_REGNUM
)
560 unsigned char val
[4];
562 memcpy (val
, FXSAVE_ADDR (regs
, i
), 2);
564 if (i
== I387_FOP_REGNUM
)
565 val
[1] &= ((1 << 3) - 1);
566 else if (i
== I387_FTAG_REGNUM
)
568 /* The fxsave area contains a simplified version of
569 the tag word. We have to look at the actual 80-bit
570 FP data to recreate the traditional i387 tag word. */
572 unsigned long ftag
= 0;
576 top
= ((FXSAVE_ADDR (regs
, I387_FSTAT_REGNUM
))[1] >> 3);
579 for (fpreg
= 7; fpreg
>= 0; fpreg
--)
583 if (val
[0] & (1 << fpreg
))
585 int regnum
= (fpreg
+ 8 - top
) % 8 + I387_ST0_REGNUM
;
586 tag
= i387_tag (FXSAVE_ADDR (regs
, regnum
));
591 ftag
|= tag
<< (2 * fpreg
);
593 val
[0] = ftag
& 0xff;
594 val
[1] = (ftag
>> 8) & 0xff;
596 regcache_raw_supply (regcache
, i
, val
);
599 regcache_raw_supply (regcache
, i
, FXSAVE_ADDR (regs
, i
));
602 if (regnum
== I387_MXCSR_REGNUM
|| regnum
== -1)
605 regcache_raw_supply (regcache
, I387_MXCSR_REGNUM
, NULL
);
607 regcache_raw_supply (regcache
, I387_MXCSR_REGNUM
,
608 FXSAVE_MXCSR_ADDR (regs
));
611 #undef I387_ST0_REGNUM
612 #undef I387_NUM_XMM_REGS
615 /* Fill register REGNUM (if it is a floating-point or SSE register) in
616 *FXSAVE with the value in GDB's register cache. If REGNUM is -1, do
617 this for all registers. This function doesn't touch any of the
618 reserved bits in *FXSAVE. */
621 i387_fill_fxsave (void *fxsave
, int regnum
)
623 struct regcache
*regcache
= current_regcache
;
624 struct gdbarch_tdep
*tdep
= gdbarch_tdep (current_gdbarch
);
628 gdb_assert (tdep
->st0_regnum
>= I386_ST0_REGNUM
);
629 gdb_assert (tdep
->num_xmm_regs
> 0);
631 /* Define I387_ST0_REGNUM and I387_NUM_XMM_REGS such that we use the
632 proper definitions for REGCACHE's architecture. */
634 #define I387_ST0_REGNUM tdep->st0_regnum
635 #define I387_NUM_XMM_REGS tdep->num_xmm_regs
637 for (i
= I387_ST0_REGNUM
; i
< I387_MXCSR_REGNUM
; i
++)
638 if (regnum
== -1 || regnum
== i
)
640 /* Most of the FPU control registers occupy only 16 bits in
641 the fxsave area. Give those a special treatment. */
642 if (i
>= I387_FCTRL_REGNUM
&& i
< I387_XMM0_REGNUM
643 && i
!= I387_FIOFF_REGNUM
&& i
!= I387_FOOFF_REGNUM
)
645 unsigned char buf
[4];
647 regcache_raw_collect (regcache
, i
, buf
);
649 if (i
== I387_FOP_REGNUM
)
651 /* The opcode occupies only 11 bits. Make sure we
652 don't touch the other bits. */
653 buf
[1] &= ((1 << 3) - 1);
654 buf
[1] |= ((FXSAVE_ADDR (regs
, i
))[1] & ~((1 << 3) - 1));
656 else if (i
== I387_FTAG_REGNUM
)
658 /* Converting back is much easier. */
663 ftag
= (buf
[1] << 8) | buf
[0];
667 for (fpreg
= 7; fpreg
>= 0; fpreg
--)
669 int tag
= (ftag
>> (fpreg
* 2)) & 3;
672 buf
[0] |= (1 << fpreg
);
675 memcpy (FXSAVE_ADDR (regs
, i
), buf
, 2);
678 regcache_raw_collect (regcache
, i
, FXSAVE_ADDR (regs
, i
));
681 if (regnum
== I387_MXCSR_REGNUM
|| regnum
== -1)
682 regcache_raw_collect (regcache
, I387_MXCSR_REGNUM
,
683 FXSAVE_MXCSR_ADDR (regs
));
685 #undef I387_ST0_REGNUM
686 #undef I387_NUM_XMM_REGS
689 /* Recreate the FTW (tag word) valid bits from the 80-bit FP data in
693 i387_tag (const unsigned char *raw
)
696 unsigned int exponent
;
697 unsigned long fraction
[2];
699 integer
= raw
[7] & 0x80;
700 exponent
= (((raw
[9] & 0x7f) << 8) | raw
[8]);
701 fraction
[0] = ((raw
[3] << 24) | (raw
[2] << 16) | (raw
[1] << 8) | raw
[0]);
702 fraction
[1] = (((raw
[7] & 0x7f) << 24) | (raw
[6] << 16)
703 | (raw
[5] << 8) | raw
[4]);
705 if (exponent
== 0x7fff)
710 else if (exponent
== 0x0000)
712 if (fraction
[0] == 0x0000 && fraction
[1] == 0x0000 && !integer
)
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