Commit | Line | Data |
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c82711bd RP |
1 | /* atof_ns32k.c - turn a Flonum into a ns32k floating point number |
2 | Copyright (C) 1987 Free Software Foundation, Inc. | |
3 | ||
4 | This file is part of GAS, the GNU Assembler. | |
5 | ||
6 | GAS is free software; you can redistribute it and/or modify | |
7 | it under the terms of the GNU General Public License as published by | |
8 | the Free Software Foundation; either version 1, or (at your option) | |
9 | any later version. | |
10 | ||
11 | GAS is distributed in the hope that it will be useful, | |
12 | but WITHOUT ANY WARRANTY; without even the implied warranty of | |
13 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
14 | GNU General Public License for more details. | |
15 | ||
16 | You should have received a copy of the GNU General Public License | |
17 | along with GAS; see the file COPYING. If not, write to | |
18 | the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA. */ | |
19 | ||
20 | /* this is atof-m68k.c hacked for ns32k */ | |
21 | ||
22 | #include "as.h" | |
23 | ||
355afbcd | 24 | extern FLONUM_TYPE generic_floating_point_number; /* Flonums returned here. */ |
c82711bd | 25 | |
587c4264 | 26 | extern const char EXP_CHARS[]; |
355afbcd | 27 | /* Precision in LittleNums. */ |
c82711bd RP |
28 | #define MAX_PRECISION (4) |
29 | #define F_PRECISION (2) | |
30 | #define D_PRECISION (4) | |
31 | ||
355afbcd | 32 | /* Length in LittleNums of guard bits. */ |
c82711bd RP |
33 | #define GUARD (2) |
34 | ||
35 | int /* Number of chars in flonum type 'letter'. */ | |
36 | atof_sizeof (letter) | |
37 | char letter; | |
38 | { | |
355afbcd | 39 | int return_value; |
c82711bd RP |
40 | |
41 | /* | |
42 | * Permitting uppercase letters is probably a bad idea. | |
43 | * Please use only lower-cased letters in case the upper-cased | |
44 | * ones become unsupported! | |
45 | */ | |
46 | switch (letter) | |
47 | { | |
48 | case 'f': | |
49 | return_value = F_PRECISION; | |
50 | break; | |
51 | ||
52 | case 'd': | |
53 | return_value = D_PRECISION; | |
54 | break; | |
55 | ||
56 | default: | |
57 | return_value = 0; | |
58 | break; | |
59 | } | |
60 | return (return_value); | |
61 | } | |
62 | ||
355afbcd KR |
63 | static unsigned long int mask[] = |
64 | { | |
c82711bd RP |
65 | 0x00000000, |
66 | 0x00000001, | |
67 | 0x00000003, | |
68 | 0x00000007, | |
69 | 0x0000000f, | |
70 | 0x0000001f, | |
71 | 0x0000003f, | |
72 | 0x0000007f, | |
73 | 0x000000ff, | |
74 | 0x000001ff, | |
75 | 0x000003ff, | |
76 | 0x000007ff, | |
77 | 0x00000fff, | |
78 | 0x00001fff, | |
79 | 0x00003fff, | |
80 | 0x00007fff, | |
81 | 0x0000ffff, | |
82 | 0x0001ffff, | |
83 | 0x0003ffff, | |
84 | 0x0007ffff, | |
85 | 0x000fffff, | |
86 | 0x001fffff, | |
87 | 0x003fffff, | |
88 | 0x007fffff, | |
89 | 0x00ffffff, | |
90 | 0x01ffffff, | |
91 | 0x03ffffff, | |
92 | 0x07ffffff, | |
93 | 0x0fffffff, | |
94 | 0x1fffffff, | |
95 | 0x3fffffff, | |
96 | 0x7fffffff, | |
97 | 0xffffffff | |
355afbcd | 98 | }; |
c82711bd RP |
99 | \f |
100 | static int bits_left_in_littlenum; | |
101 | static int littlenums_left; | |
355afbcd | 102 | static LITTLENUM_TYPE *littlenum_pointer; |
c82711bd RP |
103 | |
104 | static int | |
105 | next_bits (number_of_bits) | |
355afbcd | 106 | int number_of_bits; |
c82711bd | 107 | { |
355afbcd | 108 | int return_value; |
c82711bd | 109 | |
355afbcd KR |
110 | if (!littlenums_left) |
111 | return 0; | |
c82711bd RP |
112 | if (number_of_bits >= bits_left_in_littlenum) |
113 | { | |
355afbcd | 114 | return_value = mask[bits_left_in_littlenum] & *littlenum_pointer; |
c82711bd RP |
115 | number_of_bits -= bits_left_in_littlenum; |
116 | return_value <<= number_of_bits; | |
355afbcd KR |
117 | if (littlenums_left) |
118 | { | |
119 | bits_left_in_littlenum = LITTLENUM_NUMBER_OF_BITS - number_of_bits; | |
120 | littlenum_pointer--; | |
121 | --littlenums_left; | |
122 | return_value |= (*littlenum_pointer >> bits_left_in_littlenum) & mask[number_of_bits]; | |
123 | } | |
c82711bd RP |
124 | } |
125 | else | |
126 | { | |
127 | bits_left_in_littlenum -= number_of_bits; | |
355afbcd | 128 | return_value = mask[number_of_bits] & (*littlenum_pointer >> bits_left_in_littlenum); |
c82711bd RP |
129 | } |
130 | return (return_value); | |
131 | } | |
132 | ||
133 | static void | |
134 | make_invalid_floating_point_number (words) | |
355afbcd | 135 | LITTLENUM_TYPE *words; |
c82711bd | 136 | { |
355afbcd KR |
137 | words[0] = ((unsigned) -1) >> 1; /* Zero the leftmost bit */ |
138 | words[1] = -1; | |
139 | words[2] = -1; | |
140 | words[3] = -1; | |
c82711bd RP |
141 | } |
142 | \f | |
143 | /***********************************************************************\ | |
144 | * * | |
145 | * Warning: this returns 16-bit LITTLENUMs, because that is * | |
146 | * what the VAX thinks in. It is up to the caller to figure * | |
147 | * out any alignment problems and to conspire for the bytes/word * | |
148 | * to be emitted in the right order. Bigendians beware! * | |
149 | * * | |
150 | \***********************************************************************/ | |
151 | ||
152 | char * /* Return pointer past text consumed. */ | |
153 | atof_ns32k (str, what_kind, words) | |
355afbcd KR |
154 | char *str; /* Text to convert to binary. */ |
155 | char what_kind; /* 'd', 'f', 'g', 'h' */ | |
156 | LITTLENUM_TYPE *words; /* Build the binary here. */ | |
c82711bd | 157 | { |
355afbcd KR |
158 | FLONUM_TYPE f; |
159 | LITTLENUM_TYPE bits[MAX_PRECISION + MAX_PRECISION + GUARD]; | |
160 | /* Extra bits for zeroed low-order bits. */ | |
161 | /* The 1st MAX_PRECISION are zeroed, */ | |
162 | /* the last contain flonum bits. */ | |
163 | char *return_value; | |
164 | int precision; /* Number of 16-bit words in the format. */ | |
165 | long int exponent_bits; | |
166 | ||
167 | long int exponent_1; | |
168 | long int exponent_2; | |
169 | long int exponent_3; | |
170 | long int exponent_4; | |
171 | int exponent_skippage; | |
172 | LITTLENUM_TYPE word1; | |
173 | LITTLENUM_TYPE *lp; | |
174 | ||
175 | return_value = str; | |
176 | f.low = bits + MAX_PRECISION; | |
177 | f.high = NULL; | |
178 | f.leader = NULL; | |
179 | f.exponent = NULL; | |
180 | f.sign = '\0'; | |
181 | ||
182 | /* Use more LittleNums than seems */ | |
183 | /* necessary: the highest flonum may have */ | |
184 | /* 15 leading 0 bits, so could be useless. */ | |
185 | ||
186 | bzero (bits, sizeof (LITTLENUM_TYPE) * MAX_PRECISION); | |
187 | ||
188 | switch (what_kind) | |
189 | { | |
190 | case 'f': | |
191 | precision = F_PRECISION; | |
192 | exponent_bits = 8; | |
193 | break; | |
c82711bd | 194 | |
355afbcd KR |
195 | case 'd': |
196 | precision = D_PRECISION; | |
197 | exponent_bits = 11; | |
198 | break; | |
c82711bd | 199 | |
355afbcd KR |
200 | default: |
201 | make_invalid_floating_point_number (words); | |
202 | return NULL; | |
203 | } | |
c82711bd | 204 | |
355afbcd | 205 | f.high = f.low + precision - 1 + GUARD; |
c82711bd | 206 | |
355afbcd KR |
207 | if (atof_generic (&return_value, ".", EXP_CHARS, &f)) |
208 | { | |
209 | as_warn ("Error converting floating point number (Exponent overflow?)"); | |
210 | make_invalid_floating_point_number (words); | |
211 | return NULL; | |
212 | } | |
213 | ||
214 | if (f.low > f.leader) | |
215 | { | |
216 | /* 0.0e0 seen. */ | |
217 | bzero (words, sizeof (LITTLENUM_TYPE) * precision); | |
218 | return return_value; | |
219 | } | |
220 | ||
221 | if (f.sign != '+' && f.sign != '-') | |
222 | { | |
223 | make_invalid_floating_point_number (words); | |
224 | return NULL; | |
225 | } | |
c82711bd RP |
226 | |
227 | ||
355afbcd | 228 | /* |
c82711bd RP |
229 | * All vaxen floating_point formats (so far) have: |
230 | * Bit 15 is sign bit. | |
231 | * Bits 14:n are excess-whatever exponent. | |
232 | * Bits n-1:0 (if any) are most significant bits of fraction. | |
233 | * Bits 15:0 of the next word are the next most significant bits. | |
234 | * And so on for each other word. | |
235 | * | |
236 | * So we need: number of bits of exponent, number of bits of | |
237 | * mantissa. | |
238 | */ | |
355afbcd KR |
239 | bits_left_in_littlenum = LITTLENUM_NUMBER_OF_BITS; |
240 | littlenum_pointer = f.leader; | |
241 | littlenums_left = 1 + f.leader - f.low; | |
242 | /* Seek (and forget) 1st significant bit */ | |
243 | for (exponent_skippage = 0; !next_bits (1); exponent_skippage++) | |
244 | ; | |
245 | exponent_1 = f.exponent + f.leader + 1 - f.low; | |
246 | /* Radix LITTLENUM_RADIX, point just higher than f.leader. */ | |
247 | exponent_2 = exponent_1 * LITTLENUM_NUMBER_OF_BITS; | |
248 | /* Radix 2. */ | |
249 | exponent_3 = exponent_2 - exponent_skippage; | |
250 | /* Forget leading zeros, forget 1st bit. */ | |
251 | exponent_4 = exponent_3 + ((1 << (exponent_bits - 1)) - 2); | |
252 | /* Offset exponent. */ | |
253 | ||
254 | if (exponent_4 & ~mask[exponent_bits]) | |
255 | { | |
256 | /* | |
c82711bd RP |
257 | * Exponent overflow. Lose immediately. |
258 | */ | |
259 | ||
355afbcd | 260 | /* |
c82711bd RP |
261 | * We leave return_value alone: admit we read the |
262 | * number, but return a floating exception | |
263 | * because we can't encode the number. | |
264 | */ | |
265 | ||
355afbcd KR |
266 | as_warn ("Exponent overflow in floating-point number"); |
267 | make_invalid_floating_point_number (words); | |
268 | return return_value; | |
269 | } | |
270 | lp = words; | |
c82711bd | 271 | |
355afbcd KR |
272 | /* Word 1. Sign, exponent and perhaps high bits. */ |
273 | /* Assume 2's complement integers. */ | |
274 | word1 = ((exponent_4 & mask[exponent_bits]) << (15 - exponent_bits)) | | |
275 | ((f.sign == '+') ? 0 : 0x8000) | next_bits (15 - exponent_bits); | |
276 | *lp++ = word1; | |
c82711bd | 277 | |
355afbcd KR |
278 | /* The rest of the words are just mantissa bits. */ |
279 | for (; lp < words + precision; lp++) | |
280 | *lp = next_bits (LITTLENUM_NUMBER_OF_BITS); | |
c82711bd | 281 | |
355afbcd KR |
282 | if (next_bits (1)) |
283 | { | |
284 | unsigned long int carry; | |
285 | /* | |
c82711bd RP |
286 | * Since the NEXT bit is a 1, round UP the mantissa. |
287 | * The cunning design of these hidden-1 floats permits | |
288 | * us to let the mantissa overflow into the exponent, and | |
289 | * it 'does the right thing'. However, we lose if the | |
290 | * highest-order bit of the lowest-order word flips. | |
291 | * Is that clear? | |
292 | */ | |
293 | ||
294 | ||
355afbcd | 295 | /* #if (sizeof(carry)) < ((sizeof(bits[0]) * BITS_PER_CHAR) + 2) |
c82711bd RP |
296 | Please allow at least 1 more bit in carry than is in a LITTLENUM. |
297 | We need that extra bit to hold a carry during a LITTLENUM carry | |
298 | propagation. Another extra bit (kept 0) will assure us that we | |
299 | don't get a sticky sign bit after shifting right, and that | |
300 | permits us to propagate the carry without any masking of bits. | |
301 | #endif */ | |
355afbcd KR |
302 | for (carry = 1, lp--; carry && (lp >= words); lp--) |
303 | { | |
304 | carry = *lp + carry; | |
305 | *lp = carry; | |
306 | carry >>= LITTLENUM_NUMBER_OF_BITS; | |
307 | } | |
308 | if ((word1 ^ *words) & (1 << (LITTLENUM_NUMBER_OF_BITS - 1))) | |
309 | { | |
310 | /* We leave return_value alone: admit we read the | |
c82711bd RP |
311 | * number, but return a floating exception |
312 | * because we can't encode the number. | |
313 | */ | |
355afbcd KR |
314 | make_invalid_floating_point_number (words); |
315 | return return_value; | |
c82711bd | 316 | } |
355afbcd KR |
317 | } |
318 | return (return_value); | |
c82711bd RP |
319 | } |
320 | ||
321 | /* This is really identical to atof_ns32k except for some details */ | |
322 | ||
355afbcd KR |
323 | gen_to_words (words, precision, exponent_bits) |
324 | LITTLENUM_TYPE *words; | |
325 | long int exponent_bits; | |
c82711bd | 326 | { |
355afbcd | 327 | int return_value = 0; |
c82711bd | 328 | |
355afbcd KR |
329 | long int exponent_1; |
330 | long int exponent_2; | |
331 | long int exponent_3; | |
332 | long int exponent_4; | |
333 | int exponent_skippage; | |
334 | LITTLENUM_TYPE word1; | |
335 | LITTLENUM_TYPE *lp; | |
336 | ||
337 | if (generic_floating_point_number.low > generic_floating_point_number.leader) | |
338 | { | |
339 | /* 0.0e0 seen. */ | |
340 | bzero (words, sizeof (LITTLENUM_TYPE) * precision); | |
341 | return return_value; | |
342 | } | |
343 | ||
344 | /* | |
c82711bd RP |
345 | * All vaxen floating_point formats (so far) have: |
346 | * Bit 15 is sign bit. | |
347 | * Bits 14:n are excess-whatever exponent. | |
348 | * Bits n-1:0 (if any) are most significant bits of fraction. | |
349 | * Bits 15:0 of the next word are the next most significant bits. | |
350 | * And so on for each other word. | |
351 | * | |
352 | * So we need: number of bits of exponent, number of bits of | |
353 | * mantissa. | |
354 | */ | |
355afbcd KR |
355 | bits_left_in_littlenum = LITTLENUM_NUMBER_OF_BITS; |
356 | littlenum_pointer = generic_floating_point_number.leader; | |
357 | littlenums_left = 1 + generic_floating_point_number.leader - generic_floating_point_number.low; | |
358 | /* Seek (and forget) 1st significant bit */ | |
359 | for (exponent_skippage = 0; !next_bits (1); exponent_skippage++) | |
360 | ; | |
361 | exponent_1 = generic_floating_point_number.exponent + generic_floating_point_number.leader + 1 - | |
362 | generic_floating_point_number.low; | |
363 | /* Radix LITTLENUM_RADIX, point just higher than generic_floating_point_number.leader. */ | |
364 | exponent_2 = exponent_1 * LITTLENUM_NUMBER_OF_BITS; | |
365 | /* Radix 2. */ | |
366 | exponent_3 = exponent_2 - exponent_skippage; | |
367 | /* Forget leading zeros, forget 1st bit. */ | |
368 | exponent_4 = exponent_3 + ((1 << (exponent_bits - 1)) - 2); | |
369 | /* Offset exponent. */ | |
370 | ||
371 | if (exponent_4 & ~mask[exponent_bits]) | |
372 | { | |
373 | /* | |
c82711bd RP |
374 | * Exponent overflow. Lose immediately. |
375 | */ | |
376 | ||
355afbcd | 377 | /* |
c82711bd RP |
378 | * We leave return_value alone: admit we read the |
379 | * number, but return a floating exception | |
380 | * because we can't encode the number. | |
381 | */ | |
382 | ||
355afbcd KR |
383 | make_invalid_floating_point_number (words); |
384 | return return_value; | |
385 | } | |
386 | lp = words; | |
c82711bd | 387 | |
355afbcd KR |
388 | /* Word 1. Sign, exponent and perhaps high bits. */ |
389 | /* Assume 2's complement integers. */ | |
390 | word1 = ((exponent_4 & mask[exponent_bits]) << (15 - exponent_bits)) | | |
391 | ((generic_floating_point_number.sign == '+') ? 0 : 0x8000) | next_bits (15 - exponent_bits); | |
392 | *lp++ = word1; | |
c82711bd | 393 | |
355afbcd KR |
394 | /* The rest of the words are just mantissa bits. */ |
395 | for (; lp < words + precision; lp++) | |
396 | *lp = next_bits (LITTLENUM_NUMBER_OF_BITS); | |
c82711bd | 397 | |
355afbcd KR |
398 | if (next_bits (1)) |
399 | { | |
400 | unsigned long int carry; | |
401 | /* | |
c82711bd RP |
402 | * Since the NEXT bit is a 1, round UP the mantissa. |
403 | * The cunning design of these hidden-1 floats permits | |
404 | * us to let the mantissa overflow into the exponent, and | |
405 | * it 'does the right thing'. However, we lose if the | |
406 | * highest-order bit of the lowest-order word flips. | |
407 | * Is that clear? | |
408 | */ | |
409 | ||
410 | ||
355afbcd | 411 | /* #if (sizeof(carry)) < ((sizeof(bits[0]) * BITS_PER_CHAR) + 2) |
c82711bd RP |
412 | Please allow at least 1 more bit in carry than is in a LITTLENUM. |
413 | We need that extra bit to hold a carry during a LITTLENUM carry | |
414 | propagation. Another extra bit (kept 0) will assure us that we | |
415 | don't get a sticky sign bit after shifting right, and that | |
416 | permits us to propagate the carry without any masking of bits. | |
417 | #endif */ | |
355afbcd KR |
418 | for (carry = 1, lp--; carry && (lp >= words); lp--) |
419 | { | |
420 | carry = *lp + carry; | |
421 | *lp = carry; | |
422 | carry >>= LITTLENUM_NUMBER_OF_BITS; | |
423 | } | |
424 | if ((word1 ^ *words) & (1 << (LITTLENUM_NUMBER_OF_BITS - 1))) | |
425 | { | |
426 | /* We leave return_value alone: admit we read the | |
c82711bd RP |
427 | * number, but return a floating exception |
428 | * because we can't encode the number. | |
429 | */ | |
355afbcd KR |
430 | make_invalid_floating_point_number (words); |
431 | return return_value; | |
c82711bd | 432 | } |
355afbcd KR |
433 | } |
434 | return (return_value); | |
c82711bd RP |
435 | } |
436 | ||
437 | /* This routine is a real kludge. Someone really should do it better, but | |
438 | I'm too lazy, and I don't understand this stuff all too well anyway | |
439 | (JF) | |
440 | */ | |
355afbcd KR |
441 | void |
442 | int_to_gen (x) | |
443 | long x; | |
c82711bd | 444 | { |
355afbcd KR |
445 | char buf[20]; |
446 | char *bufp; | |
c82711bd | 447 | |
355afbcd KR |
448 | sprintf (buf, "%ld", x); |
449 | bufp = &buf[0]; | |
450 | if (atof_generic (&bufp, ".", EXP_CHARS, &generic_floating_point_number)) | |
451 | as_warn ("Error converting number to floating point (Exponent overflow?)"); | |
c82711bd | 452 | } |