1 /* Intel 387 floating point stuff.
2 Copyright 1988, 1989, 1991, 1992, 1993, 1994, 1998, 1999, 2000, 2001
3 Free Software Foundation, Inc.
5 This file is part of GDB.
7 This program is free software; you can redistribute it and/or modify
8 it under the terms of the GNU General Public License as published by
9 the Free Software Foundation; either version 2 of the License, or
10 (at your option) any later version.
12 This program is distributed in the hope that it will be useful,
13 but WITHOUT ANY WARRANTY; without even the implied warranty of
14 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
15 GNU General Public License for more details.
17 You should have received a copy of the GNU General Public License
18 along with this program; if not, write to the Free Software
19 Foundation, Inc., 59 Temple Place - Suite 330,
20 Boston, MA 02111-1307, USA. */
28 #include "floatformat.h"
30 #include "gdb_assert.h"
33 #include "i386-tdep.h"
35 /* FIXME: Eliminate the next two functions when we have the time to
36 change all the callers. */
38 void i387_to_double (char *from
, char *to
);
39 void double_to_i387 (char *from
, char *to
);
42 i387_to_double (char *from
, char *to
)
44 floatformat_to_double (&floatformat_i387_ext
, from
, (double *) to
);
48 double_to_i387 (char *from
, char *to
)
50 floatformat_from_double (&floatformat_i387_ext
, (double *) from
, to
);
54 /* FIXME: The functions on this page are used by the old `info float'
55 implementations that a few of the i386 targets provide. These
56 functions should be removed if all of these have been converted to
57 use the generic implementation based on the new register file
60 static void print_387_control_bits (unsigned int control
);
61 static void print_387_status_bits (unsigned int status
);
64 print_387_control_bits (unsigned int control
)
66 switch ((control
>> 8) & 3)
69 puts_unfiltered (" 24 bit; ");
72 puts_unfiltered (" (bad); ");
75 puts_unfiltered (" 53 bit; ");
78 puts_unfiltered (" 64 bit; ");
81 switch ((control
>> 10) & 3)
84 puts_unfiltered ("NEAR; ");
87 puts_unfiltered ("DOWN; ");
90 puts_unfiltered ("UP; ");
93 puts_unfiltered ("CHOP; ");
98 puts_unfiltered ("mask");
100 puts_unfiltered (" INVAL");
101 if (control
& 0x0002)
102 puts_unfiltered (" DENOR");
103 if (control
& 0x0004)
104 puts_unfiltered (" DIVZ");
105 if (control
& 0x0008)
106 puts_unfiltered (" OVERF");
107 if (control
& 0x0010)
108 puts_unfiltered (" UNDER");
109 if (control
& 0x0020)
110 puts_unfiltered (" LOS");
111 puts_unfiltered (";");
114 if (control
& 0xe080)
115 warning ("\nreserved bits on: %s",
116 local_hex_string (control
& 0xe080));
120 print_387_control_word (unsigned int control
)
122 printf_filtered ("control %s:", local_hex_string(control
& 0xffff));
123 print_387_control_bits (control
);
124 puts_unfiltered ("\n");
128 print_387_status_bits (unsigned int status
)
130 printf_unfiltered (" flags %d%d%d%d; ",
131 (status
& 0x4000) != 0,
132 (status
& 0x0400) != 0,
133 (status
& 0x0200) != 0,
134 (status
& 0x0100) != 0);
135 printf_unfiltered ("top %d; ", (status
>> 11) & 7);
138 puts_unfiltered ("excep");
139 if (status
& 0x0001) puts_unfiltered (" INVAL");
140 if (status
& 0x0002) puts_unfiltered (" DENOR");
141 if (status
& 0x0004) puts_unfiltered (" DIVZ");
142 if (status
& 0x0008) puts_unfiltered (" OVERF");
143 if (status
& 0x0010) puts_unfiltered (" UNDER");
144 if (status
& 0x0020) puts_unfiltered (" LOS");
145 if (status
& 0x0040) puts_unfiltered (" STACK");
150 print_387_status_word (unsigned int status
)
152 printf_filtered ("status %s:", local_hex_string (status
& 0xffff));
153 print_387_status_bits (status
);
154 puts_unfiltered ("\n");
158 /* Implement the `info float' layout based on the register definitions
161 /* Print the floating point number specified by RAW. */
163 print_i387_value (char *raw
)
167 /* Using extract_typed_floating here might affect the representation
168 of certain numbers such as NaNs, even if GDB is running natively.
169 This is fine since our caller already detects such special
170 numbers and we print the hexadecimal representation anyway. */
171 value
= extract_typed_floating (raw
, builtin_type_i387_ext
);
173 /* We try to print 19 digits. The last digit may or may not contain
174 garbage, but we'd better print one too many. We need enough room
175 to print the value, 1 position for the sign, 1 for the decimal
176 point, 19 for the digits and 6 for the exponent adds up to 27. */
177 #ifdef PRINTF_HAS_LONG_DOUBLE
178 printf_filtered (" %-+27.19Lg", (long double) value
);
180 printf_filtered (" %-+27.19g", (double) value
);
184 /* Print the classification for the register contents RAW. */
186 print_i387_ext (unsigned char *raw
)
190 unsigned int exponent
;
191 unsigned long fraction
[2];
193 sign
= raw
[9] & 0x80;
194 integer
= raw
[7] & 0x80;
195 exponent
= (((raw
[9] & 0x7f) << 8) | raw
[8]);
196 fraction
[0] = ((raw
[3] << 24) | (raw
[2] << 16) | (raw
[1] << 8) | raw
[0]);
197 fraction
[1] = (((raw
[7] & 0x7f) << 24) | (raw
[6] << 16)
198 | (raw
[5] << 8) | raw
[4]);
200 if (exponent
== 0x7fff && integer
)
202 if (fraction
[0] == 0x00000000 && fraction
[1] == 0x00000000)
204 printf_filtered (" %cInf", (sign
? '-' : '+'));
205 else if (sign
&& fraction
[0] == 0x00000000 && fraction
[1] == 0x40000000)
206 /* Real Indefinite (QNaN). */
207 puts_unfiltered (" Real Indefinite (QNaN)");
208 else if (fraction
[1] & 0x40000000)
210 puts_filtered (" QNaN");
213 puts_filtered (" SNaN");
215 else if (exponent
< 0x7fff && exponent
> 0x0000 && integer
)
217 print_i387_value (raw
);
218 else if (exponent
== 0x0000)
220 /* Denormal or zero. */
221 print_i387_value (raw
);
224 /* Pseudo-denormal. */
225 puts_filtered (" Pseudo-denormal");
226 else if (fraction
[0] || fraction
[1])
228 puts_filtered (" Denormal");
232 puts_filtered (" Unsupported");
235 /* Print the status word STATUS. */
237 print_i387_status_word (unsigned int status
)
239 printf_filtered ("Status Word: %s",
240 local_hex_string_custom (status
, "04"));
242 printf_filtered (" %s", (status
& 0x0001) ? "IE" : " ");
243 printf_filtered (" %s", (status
& 0x0002) ? "DE" : " ");
244 printf_filtered (" %s", (status
& 0x0004) ? "ZE" : " ");
245 printf_filtered (" %s", (status
& 0x0008) ? "OE" : " ");
246 printf_filtered (" %s", (status
& 0x0010) ? "UE" : " ");
247 printf_filtered (" %s", (status
& 0x0020) ? "PE" : " ");
249 printf_filtered (" %s", (status
& 0x0080) ? "ES" : " ");
251 printf_filtered (" %s", (status
& 0x0040) ? "SF" : " ");
253 printf_filtered (" %s", (status
& 0x0100) ? "C0" : " ");
254 printf_filtered (" %s", (status
& 0x0200) ? "C1" : " ");
255 printf_filtered (" %s", (status
& 0x0400) ? "C2" : " ");
256 printf_filtered (" %s", (status
& 0x4000) ? "C3" : " ");
258 puts_filtered ("\n");
260 printf_filtered (" TOP: %d\n", ((status
>> 11) & 7));
263 /* Print the control word CONTROL. */
265 print_i387_control_word (unsigned int control
)
267 printf_filtered ("Control Word: %s",
268 local_hex_string_custom (control
, "04"));
270 printf_filtered (" %s", (control
& 0x0001) ? "IM" : " ");
271 printf_filtered (" %s", (control
& 0x0002) ? "DM" : " ");
272 printf_filtered (" %s", (control
& 0x0004) ? "ZM" : " ");
273 printf_filtered (" %s", (control
& 0x0008) ? "OM" : " ");
274 printf_filtered (" %s", (control
& 0x0010) ? "UM" : " ");
275 printf_filtered (" %s", (control
& 0x0020) ? "PM" : " ");
277 puts_filtered ("\n");
279 puts_filtered (" PC: ");
280 switch ((control
>> 8) & 3)
283 puts_filtered ("Single Precision (24-bits)\n");
286 puts_filtered ("Reserved\n");
289 puts_filtered ("Double Precision (53-bits)\n");
292 puts_filtered ("Extended Precision (64-bits)\n");
296 puts_filtered (" RC: ");
297 switch ((control
>> 10) & 3)
300 puts_filtered ("Round to nearest\n");
303 puts_filtered ("Round down\n");
306 puts_filtered ("Round up\n");
309 puts_filtered ("Round toward zero\n");
314 /* Print out the i387 floating poin state. */
316 i387_float_info (void)
329 fctrl
= read_register (FCTRL_REGNUM
);
330 fstat
= read_register (FSTAT_REGNUM
);
331 ftag
= read_register (FTAG_REGNUM
);
332 fiseg
= read_register (FCS_REGNUM
);
333 fioff
= read_register (FCOFF_REGNUM
);
334 foseg
= read_register (FDS_REGNUM
);
335 fooff
= read_register (FDOFF_REGNUM
);
336 fop
= read_register (FOP_REGNUM
);
338 top
= ((fstat
>> 11) & 7);
340 for (fpreg
= 7; fpreg
>= 0; fpreg
--)
342 unsigned char raw
[FPU_REG_RAW_SIZE
];
343 int tag
= (ftag
>> (fpreg
* 2)) & 3;
346 printf_filtered ("%sR%d: ", fpreg
== top
? "=>" : " ", fpreg
);
351 puts_filtered ("Valid ");
354 puts_filtered ("Zero ");
357 puts_filtered ("Special ");
360 puts_filtered ("Empty ");
364 read_register_gen ((fpreg
+ 8 - top
) % 8 + FP0_REGNUM
, raw
);
366 puts_filtered ("0x");
367 for (i
= 9; i
>= 0; i
--)
368 printf_filtered ("%02x", raw
[i
]);
371 print_i387_ext (raw
);
373 puts_filtered ("\n");
376 puts_filtered ("\n");
378 print_i387_status_word (fstat
);
379 print_i387_control_word (fctrl
);
380 printf_filtered ("Tag Word: %s\n",
381 local_hex_string_custom (ftag
, "04"));
382 printf_filtered ("Instruction Pointer: %s:",
383 local_hex_string_custom (fiseg
, "02"));
384 printf_filtered ("%s\n", local_hex_string_custom (fioff
, "08"));
385 printf_filtered ("Operand Pointer: %s:",
386 local_hex_string_custom (foseg
, "02"));
387 printf_filtered ("%s\n", local_hex_string_custom (fooff
, "08"));
388 printf_filtered ("Opcode: %s\n",
389 local_hex_string_custom (fop
? (fop
| 0xd800) : 0, "04"));
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