1 | /* Fixed-point arithmetic support. |
2 | Copyright (C) 2006-2023 Free Software Foundation, Inc. |
3 | |
4 | This file is part of GCC. |
5 | |
6 | GCC is free software; you can redistribute it and/or modify it under |
7 | the terms of the GNU General Public License as published by the Free |
8 | Software Foundation; either version 3, or (at your option) any later |
9 | version. |
10 | |
11 | GCC is distributed in the hope that it will be useful, but WITHOUT ANY |
12 | WARRANTY; without even the implied warranty of MERCHANTABILITY or |
13 | FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License |
14 | for more details. |
15 | |
16 | You should have received a copy of the GNU General Public License |
17 | along with GCC; see the file COPYING3. If not see |
18 | <http://www.gnu.org/licenses/>. */ |
19 | |
20 | #include "config.h" |
21 | #include "system.h" |
22 | #include "coretypes.h" |
23 | #include "tm.h" |
24 | #include "tree.h" |
25 | #include "diagnostic-core.h" |
26 | |
27 | /* Compare two fixed objects for bitwise identity. */ |
28 | |
29 | bool |
30 | fixed_identical (const FIXED_VALUE_TYPE *a, const FIXED_VALUE_TYPE *b) |
31 | { |
32 | return (a->mode == b->mode |
33 | && a->data.high == b->data.high |
34 | && a->data.low == b->data.low); |
35 | } |
36 | |
37 | /* Calculate a hash value. */ |
38 | |
39 | unsigned int |
40 | fixed_hash (const FIXED_VALUE_TYPE *f) |
41 | { |
42 | return (unsigned int) (f->data.low ^ f->data.high); |
43 | } |
44 | |
45 | /* Define the enum code for the range of the fixed-point value. */ |
46 | enum fixed_value_range_code { |
47 | FIXED_OK, /* The value is within the range. */ |
48 | FIXED_UNDERFLOW, /* The value is less than the minimum. */ |
49 | FIXED_GT_MAX_EPS, /* The value is greater than the maximum, but not equal |
50 | to the maximum plus the epsilon. */ |
51 | FIXED_MAX_EPS /* The value equals the maximum plus the epsilon. */ |
52 | }; |
53 | |
54 | /* Check REAL_VALUE against the range of the fixed-point mode. |
55 | Return FIXED_OK, if it is within the range. |
56 | FIXED_UNDERFLOW, if it is less than the minimum. |
57 | FIXED_GT_MAX_EPS, if it is greater than the maximum, but not equal to |
58 | the maximum plus the epsilon. |
59 | FIXED_MAX_EPS, if it is equal to the maximum plus the epsilon. */ |
60 | |
61 | static enum fixed_value_range_code |
62 | check_real_for_fixed_mode (REAL_VALUE_TYPE *real_value, machine_mode mode) |
63 | { |
64 | REAL_VALUE_TYPE max_value, min_value, epsilon_value; |
65 | |
66 | real_2expN (&max_value, GET_MODE_IBIT (mode), VOIDmode); |
67 | real_2expN (&epsilon_value, -GET_MODE_FBIT (mode), VOIDmode); |
68 | |
69 | if (SIGNED_FIXED_POINT_MODE_P (mode)) |
70 | min_value = real_value_negate (&max_value); |
71 | else |
72 | real_from_string (&min_value, "0.0" ); |
73 | |
74 | if (real_compare (LT_EXPR, real_value, &min_value)) |
75 | return FIXED_UNDERFLOW; |
76 | if (real_compare (EQ_EXPR, real_value, &max_value)) |
77 | return FIXED_MAX_EPS; |
78 | real_arithmetic (&max_value, MINUS_EXPR, &max_value, &epsilon_value); |
79 | if (real_compare (GT_EXPR, real_value, &max_value)) |
80 | return FIXED_GT_MAX_EPS; |
81 | return FIXED_OK; |
82 | } |
83 | |
84 | |
85 | /* Construct a CONST_FIXED from a bit payload and machine mode MODE. |
86 | The bits in PAYLOAD are sign-extended/zero-extended according to MODE. */ |
87 | |
88 | FIXED_VALUE_TYPE |
89 | fixed_from_double_int (double_int payload, scalar_mode mode) |
90 | { |
91 | FIXED_VALUE_TYPE value; |
92 | |
93 | gcc_assert (GET_MODE_BITSIZE (mode) <= HOST_BITS_PER_DOUBLE_INT); |
94 | |
95 | if (SIGNED_SCALAR_FIXED_POINT_MODE_P (mode)) |
96 | value.data = payload.sext (prec: 1 + GET_MODE_IBIT (mode) + GET_MODE_FBIT (mode)); |
97 | else if (UNSIGNED_SCALAR_FIXED_POINT_MODE_P (mode)) |
98 | value.data = payload.zext (GET_MODE_IBIT (mode) + GET_MODE_FBIT (mode)); |
99 | else |
100 | gcc_unreachable (); |
101 | |
102 | value.mode = mode; |
103 | |
104 | return value; |
105 | } |
106 | |
107 | |
108 | /* Initialize from a decimal or hexadecimal string. */ |
109 | |
110 | void |
111 | fixed_from_string (FIXED_VALUE_TYPE *f, const char *str, scalar_mode mode) |
112 | { |
113 | REAL_VALUE_TYPE real_value, fixed_value, base_value; |
114 | unsigned int fbit; |
115 | enum fixed_value_range_code temp; |
116 | bool fail; |
117 | |
118 | f->mode = mode; |
119 | fbit = GET_MODE_FBIT (mode); |
120 | |
121 | real_from_string (&real_value, str); |
122 | temp = check_real_for_fixed_mode (real_value: &real_value, mode: f->mode); |
123 | /* We don't want to warn the case when the _Fract value is 1.0. */ |
124 | if (temp == FIXED_UNDERFLOW |
125 | || temp == FIXED_GT_MAX_EPS |
126 | || (temp == FIXED_MAX_EPS && ALL_ACCUM_MODE_P (f->mode))) |
127 | warning (OPT_Woverflow, |
128 | "large fixed-point constant implicitly truncated to fixed-point type" ); |
129 | real_2expN (&base_value, fbit, VOIDmode); |
130 | real_arithmetic (&fixed_value, MULT_EXPR, &real_value, &base_value); |
131 | wide_int w = real_to_integer (&fixed_value, &fail, |
132 | GET_MODE_PRECISION (mode)); |
133 | f->data.low = w.ulow (); |
134 | f->data.high = w.elt (i: 1); |
135 | |
136 | if (temp == FIXED_MAX_EPS && ALL_FRACT_MODE_P (f->mode)) |
137 | { |
138 | /* From the spec, we need to evaluate 1 to the maximal value. */ |
139 | f->data.low = -1; |
140 | f->data.high = -1; |
141 | f->data = f->data.zext (GET_MODE_FBIT (f->mode) |
142 | + GET_MODE_IBIT (f->mode)); |
143 | } |
144 | else |
145 | f->data = f->data.ext (SIGNED_FIXED_POINT_MODE_P (f->mode) |
146 | + GET_MODE_FBIT (f->mode) |
147 | + GET_MODE_IBIT (f->mode), |
148 | UNSIGNED_FIXED_POINT_MODE_P (f->mode)); |
149 | } |
150 | |
151 | /* Render F as a decimal floating point constant. */ |
152 | |
153 | void |
154 | fixed_to_decimal (char *str, const FIXED_VALUE_TYPE *f_orig, |
155 | size_t buf_size) |
156 | { |
157 | REAL_VALUE_TYPE real_value, base_value, fixed_value; |
158 | |
159 | signop sgn = UNSIGNED_FIXED_POINT_MODE_P (f_orig->mode) ? UNSIGNED : SIGNED; |
160 | real_2expN (&base_value, GET_MODE_FBIT (f_orig->mode), VOIDmode); |
161 | real_from_integer (&real_value, VOIDmode, |
162 | wide_int::from (x: f_orig->data, |
163 | precision: GET_MODE_PRECISION (mode: f_orig->mode), sgn), |
164 | sgn); |
165 | real_arithmetic (&fixed_value, RDIV_EXPR, &real_value, &base_value); |
166 | real_to_decimal (str, &fixed_value, buf_size, 0, 1); |
167 | } |
168 | |
169 | /* If SAT_P, saturate A to the maximum or the minimum, and save to *F based on |
170 | the machine mode MODE. |
171 | Do not modify *F otherwise. |
172 | This function assumes the width of double_int is greater than the width |
173 | of the fixed-point value (the sum of a possible sign bit, possible ibits, |
174 | and fbits). |
175 | Return true, if !SAT_P and overflow. */ |
176 | |
177 | static bool |
178 | fixed_saturate1 (machine_mode mode, double_int a, double_int *f, |
179 | bool sat_p) |
180 | { |
181 | bool overflow_p = false; |
182 | bool unsigned_p = UNSIGNED_FIXED_POINT_MODE_P (mode); |
183 | int i_f_bits = GET_MODE_IBIT (mode) + GET_MODE_FBIT (mode); |
184 | |
185 | if (unsigned_p) /* Unsigned type. */ |
186 | { |
187 | double_int max; |
188 | max.low = -1; |
189 | max.high = -1; |
190 | max = max.zext (prec: i_f_bits); |
191 | if (a.ugt (b: max)) |
192 | { |
193 | if (sat_p) |
194 | *f = max; |
195 | else |
196 | overflow_p = true; |
197 | } |
198 | } |
199 | else /* Signed type. */ |
200 | { |
201 | double_int max, min; |
202 | max.high = -1; |
203 | max.low = -1; |
204 | max = max.zext (prec: i_f_bits); |
205 | min.high = 0; |
206 | min.low = 1; |
207 | min = min.alshift (count: i_f_bits, HOST_BITS_PER_DOUBLE_INT); |
208 | min = min.sext (prec: 1 + i_f_bits); |
209 | if (a.sgt (b: max)) |
210 | { |
211 | if (sat_p) |
212 | *f = max; |
213 | else |
214 | overflow_p = true; |
215 | } |
216 | else if (a.slt (b: min)) |
217 | { |
218 | if (sat_p) |
219 | *f = min; |
220 | else |
221 | overflow_p = true; |
222 | } |
223 | } |
224 | return overflow_p; |
225 | } |
226 | |
227 | /* If SAT_P, saturate {A_HIGH, A_LOW} to the maximum or the minimum, and |
228 | save to *F based on the machine mode MODE. |
229 | Do not modify *F otherwise. |
230 | This function assumes the width of two double_int is greater than the width |
231 | of the fixed-point value (the sum of a possible sign bit, possible ibits, |
232 | and fbits). |
233 | Return true, if !SAT_P and overflow. */ |
234 | |
235 | static bool |
236 | fixed_saturate2 (machine_mode mode, double_int a_high, double_int a_low, |
237 | double_int *f, bool sat_p) |
238 | { |
239 | bool overflow_p = false; |
240 | bool unsigned_p = UNSIGNED_FIXED_POINT_MODE_P (mode); |
241 | int i_f_bits = GET_MODE_IBIT (mode) + GET_MODE_FBIT (mode); |
242 | |
243 | if (unsigned_p) /* Unsigned type. */ |
244 | { |
245 | double_int max_r, max_s; |
246 | max_r.high = 0; |
247 | max_r.low = 0; |
248 | max_s.high = -1; |
249 | max_s.low = -1; |
250 | max_s = max_s.zext (prec: i_f_bits); |
251 | if (a_high.ugt (b: max_r) |
252 | || (a_high == max_r && |
253 | a_low.ugt (b: max_s))) |
254 | { |
255 | if (sat_p) |
256 | *f = max_s; |
257 | else |
258 | overflow_p = true; |
259 | } |
260 | } |
261 | else /* Signed type. */ |
262 | { |
263 | double_int max_r, max_s, min_r, min_s; |
264 | max_r.high = 0; |
265 | max_r.low = 0; |
266 | max_s.high = -1; |
267 | max_s.low = -1; |
268 | max_s = max_s.zext (prec: i_f_bits); |
269 | min_r.high = -1; |
270 | min_r.low = -1; |
271 | min_s.high = 0; |
272 | min_s.low = 1; |
273 | min_s = min_s.alshift (count: i_f_bits, HOST_BITS_PER_DOUBLE_INT); |
274 | min_s = min_s.sext (prec: 1 + i_f_bits); |
275 | if (a_high.sgt (b: max_r) |
276 | || (a_high == max_r && |
277 | a_low.ugt (b: max_s))) |
278 | { |
279 | if (sat_p) |
280 | *f = max_s; |
281 | else |
282 | overflow_p = true; |
283 | } |
284 | else if (a_high.slt (b: min_r) |
285 | || (a_high == min_r && |
286 | a_low.ult (b: min_s))) |
287 | { |
288 | if (sat_p) |
289 | *f = min_s; |
290 | else |
291 | overflow_p = true; |
292 | } |
293 | } |
294 | return overflow_p; |
295 | } |
296 | |
297 | /* Return the sign bit based on I_F_BITS. */ |
298 | |
299 | static inline int |
300 | get_fixed_sign_bit (double_int a, int i_f_bits) |
301 | { |
302 | if (i_f_bits < HOST_BITS_PER_WIDE_INT) |
303 | return (a.low >> i_f_bits) & 1; |
304 | else |
305 | return (a.high >> (i_f_bits - HOST_BITS_PER_WIDE_INT)) & 1; |
306 | } |
307 | |
308 | /* Calculate F = A + (SUBTRACT_P ? -B : B). |
309 | If SAT_P, saturate the result to the max or the min. |
310 | Return true, if !SAT_P and overflow. */ |
311 | |
312 | static bool |
313 | do_fixed_add (FIXED_VALUE_TYPE *f, const FIXED_VALUE_TYPE *a, |
314 | const FIXED_VALUE_TYPE *b, bool subtract_p, bool sat_p) |
315 | { |
316 | bool overflow_p = false; |
317 | bool unsigned_p; |
318 | double_int temp; |
319 | int i_f_bits; |
320 | |
321 | /* This was a conditional expression but it triggered a bug in |
322 | Sun C 5.5. */ |
323 | if (subtract_p) |
324 | temp = -b->data; |
325 | else |
326 | temp = b->data; |
327 | |
328 | unsigned_p = UNSIGNED_FIXED_POINT_MODE_P (a->mode); |
329 | i_f_bits = GET_MODE_IBIT (a->mode) + GET_MODE_FBIT (a->mode); |
330 | f->mode = a->mode; |
331 | f->data = a->data + temp; |
332 | if (unsigned_p) /* Unsigned type. */ |
333 | { |
334 | if (subtract_p) /* Unsigned subtraction. */ |
335 | { |
336 | if (a->data.ult (b: b->data)) |
337 | { |
338 | if (sat_p) |
339 | { |
340 | f->data.high = 0; |
341 | f->data.low = 0; |
342 | } |
343 | else |
344 | overflow_p = true; |
345 | } |
346 | } |
347 | else /* Unsigned addition. */ |
348 | { |
349 | f->data = f->data.zext (prec: i_f_bits); |
350 | if (f->data.ult (b: a->data) |
351 | || f->data.ult (b: b->data)) |
352 | { |
353 | if (sat_p) |
354 | { |
355 | f->data.high = -1; |
356 | f->data.low = -1; |
357 | } |
358 | else |
359 | overflow_p = true; |
360 | } |
361 | } |
362 | } |
363 | else /* Signed type. */ |
364 | { |
365 | if ((!subtract_p |
366 | && (get_fixed_sign_bit (a: a->data, i_f_bits) |
367 | == get_fixed_sign_bit (a: b->data, i_f_bits)) |
368 | && (get_fixed_sign_bit (a: a->data, i_f_bits) |
369 | != get_fixed_sign_bit (a: f->data, i_f_bits))) |
370 | || (subtract_p |
371 | && (get_fixed_sign_bit (a: a->data, i_f_bits) |
372 | != get_fixed_sign_bit (a: b->data, i_f_bits)) |
373 | && (get_fixed_sign_bit (a: a->data, i_f_bits) |
374 | != get_fixed_sign_bit (a: f->data, i_f_bits)))) |
375 | { |
376 | if (sat_p) |
377 | { |
378 | f->data.low = 1; |
379 | f->data.high = 0; |
380 | f->data = f->data.alshift (count: i_f_bits, HOST_BITS_PER_DOUBLE_INT); |
381 | if (get_fixed_sign_bit (a: a->data, i_f_bits) == 0) |
382 | { |
383 | --f->data; |
384 | } |
385 | } |
386 | else |
387 | overflow_p = true; |
388 | } |
389 | } |
390 | f->data = f->data.ext (prec: (!unsigned_p) + i_f_bits, uns: unsigned_p); |
391 | return overflow_p; |
392 | } |
393 | |
394 | /* Calculate F = A * B. |
395 | If SAT_P, saturate the result to the max or the min. |
396 | Return true, if !SAT_P and overflow. */ |
397 | |
398 | static bool |
399 | do_fixed_multiply (FIXED_VALUE_TYPE *f, const FIXED_VALUE_TYPE *a, |
400 | const FIXED_VALUE_TYPE *b, bool sat_p) |
401 | { |
402 | bool overflow_p = false; |
403 | bool unsigned_p = UNSIGNED_FIXED_POINT_MODE_P (a->mode); |
404 | int i_f_bits = GET_MODE_IBIT (a->mode) + GET_MODE_FBIT (a->mode); |
405 | f->mode = a->mode; |
406 | if (GET_MODE_PRECISION (mode: f->mode) <= HOST_BITS_PER_WIDE_INT) |
407 | { |
408 | f->data = a->data * b->data; |
409 | f->data = f->data.lshift (count: -GET_MODE_FBIT (f->mode), |
410 | HOST_BITS_PER_DOUBLE_INT, arith: !unsigned_p); |
411 | overflow_p = fixed_saturate1 (mode: f->mode, a: f->data, f: &f->data, sat_p); |
412 | } |
413 | else |
414 | { |
415 | /* The result of multiplication expands to two double_int. */ |
416 | double_int a_high, a_low, b_high, b_low; |
417 | double_int high_high, high_low, low_high, low_low; |
418 | double_int r, s, temp1, temp2; |
419 | int carry = 0; |
420 | |
421 | /* Decompose a and b to four double_int. */ |
422 | a_high.low = a->data.high; |
423 | a_high.high = 0; |
424 | a_low.low = a->data.low; |
425 | a_low.high = 0; |
426 | b_high.low = b->data.high; |
427 | b_high.high = 0; |
428 | b_low.low = b->data.low; |
429 | b_low.high = 0; |
430 | |
431 | /* Perform four multiplications. */ |
432 | low_low = a_low * b_low; |
433 | low_high = a_low * b_high; |
434 | high_low = a_high * b_low; |
435 | high_high = a_high * b_high; |
436 | |
437 | /* Accumulate four results to {r, s}. */ |
438 | temp1.high = high_low.low; |
439 | temp1.low = 0; |
440 | s = low_low + temp1; |
441 | if (s.ult (b: low_low) |
442 | || s.ult (b: temp1)) |
443 | carry ++; /* Carry */ |
444 | temp1.high = s.high; |
445 | temp1.low = s.low; |
446 | temp2.high = low_high.low; |
447 | temp2.low = 0; |
448 | s = temp1 + temp2; |
449 | if (s.ult (b: temp1) |
450 | || s.ult (b: temp2)) |
451 | carry ++; /* Carry */ |
452 | |
453 | temp1.low = high_low.high; |
454 | temp1.high = 0; |
455 | r = high_high + temp1; |
456 | temp1.low = low_high.high; |
457 | temp1.high = 0; |
458 | r += temp1; |
459 | temp1.low = carry; |
460 | temp1.high = 0; |
461 | r += temp1; |
462 | |
463 | /* We need to subtract b from r, if a < 0. */ |
464 | if (!unsigned_p && a->data.high < 0) |
465 | r -= b->data; |
466 | /* We need to subtract a from r, if b < 0. */ |
467 | if (!unsigned_p && b->data.high < 0) |
468 | r -= a->data; |
469 | |
470 | /* Shift right the result by FBIT. */ |
471 | if (GET_MODE_FBIT (f->mode) == HOST_BITS_PER_DOUBLE_INT) |
472 | { |
473 | s.low = r.low; |
474 | s.high = r.high; |
475 | if (unsigned_p) |
476 | { |
477 | r.low = 0; |
478 | r.high = 0; |
479 | } |
480 | else |
481 | { |
482 | r.low = -1; |
483 | r.high = -1; |
484 | } |
485 | f->data.low = s.low; |
486 | f->data.high = s.high; |
487 | } |
488 | else |
489 | { |
490 | s = s.llshift (count: (-GET_MODE_FBIT (f->mode)), HOST_BITS_PER_DOUBLE_INT); |
491 | f->data = r.llshift (count: (HOST_BITS_PER_DOUBLE_INT |
492 | - GET_MODE_FBIT (f->mode)), |
493 | HOST_BITS_PER_DOUBLE_INT); |
494 | f->data.low = f->data.low | s.low; |
495 | f->data.high = f->data.high | s.high; |
496 | s.low = f->data.low; |
497 | s.high = f->data.high; |
498 | r = r.lshift (count: -GET_MODE_FBIT (f->mode), |
499 | HOST_BITS_PER_DOUBLE_INT, arith: !unsigned_p); |
500 | } |
501 | |
502 | overflow_p = fixed_saturate2 (mode: f->mode, a_high: r, a_low: s, f: &f->data, sat_p); |
503 | } |
504 | |
505 | f->data = f->data.ext (prec: (!unsigned_p) + i_f_bits, uns: unsigned_p); |
506 | return overflow_p; |
507 | } |
508 | |
509 | /* Calculate F = A / B. |
510 | If SAT_P, saturate the result to the max or the min. |
511 | Return true, if !SAT_P and overflow. */ |
512 | |
513 | static bool |
514 | do_fixed_divide (FIXED_VALUE_TYPE *f, const FIXED_VALUE_TYPE *a, |
515 | const FIXED_VALUE_TYPE *b, bool sat_p) |
516 | { |
517 | bool overflow_p = false; |
518 | bool unsigned_p = UNSIGNED_FIXED_POINT_MODE_P (a->mode); |
519 | int i_f_bits = GET_MODE_IBIT (a->mode) + GET_MODE_FBIT (a->mode); |
520 | f->mode = a->mode; |
521 | if (GET_MODE_PRECISION (mode: f->mode) <= HOST_BITS_PER_WIDE_INT) |
522 | { |
523 | f->data = a->data.lshift (GET_MODE_FBIT (f->mode), |
524 | HOST_BITS_PER_DOUBLE_INT, arith: !unsigned_p); |
525 | f->data = f->data.div (b->data, unsigned_p, TRUNC_DIV_EXPR); |
526 | overflow_p = fixed_saturate1 (mode: f->mode, a: f->data, f: &f->data, sat_p); |
527 | } |
528 | else |
529 | { |
530 | double_int pos_a, pos_b, r, s; |
531 | double_int quo_r, quo_s, mod, temp; |
532 | int num_of_neg = 0; |
533 | int i; |
534 | |
535 | /* If a < 0, negate a. */ |
536 | if (!unsigned_p && a->data.high < 0) |
537 | { |
538 | pos_a = -a->data; |
539 | num_of_neg ++; |
540 | } |
541 | else |
542 | pos_a = a->data; |
543 | |
544 | /* If b < 0, negate b. */ |
545 | if (!unsigned_p && b->data.high < 0) |
546 | { |
547 | pos_b = -b->data; |
548 | num_of_neg ++; |
549 | } |
550 | else |
551 | pos_b = b->data; |
552 | |
553 | /* Left shift pos_a to {r, s} by FBIT. */ |
554 | if (GET_MODE_FBIT (f->mode) == HOST_BITS_PER_DOUBLE_INT) |
555 | { |
556 | r = pos_a; |
557 | s.high = 0; |
558 | s.low = 0; |
559 | } |
560 | else |
561 | { |
562 | s = pos_a.llshift (GET_MODE_FBIT (f->mode), HOST_BITS_PER_DOUBLE_INT); |
563 | r = pos_a.llshift (count: - (HOST_BITS_PER_DOUBLE_INT |
564 | - GET_MODE_FBIT (f->mode)), |
565 | HOST_BITS_PER_DOUBLE_INT); |
566 | } |
567 | |
568 | /* Divide r by pos_b to quo_r. The remainder is in mod. */ |
569 | quo_r = r.divmod (pos_b, 1, TRUNC_DIV_EXPR, &mod); |
570 | quo_s = double_int_zero; |
571 | |
572 | for (i = 0; i < HOST_BITS_PER_DOUBLE_INT; i++) |
573 | { |
574 | /* Record the leftmost bit of mod. */ |
575 | int leftmost_mod = (mod.high < 0); |
576 | |
577 | /* Shift left mod by 1 bit. */ |
578 | mod = mod.lshift (count: 1); |
579 | |
580 | /* Test the leftmost bit of s to add to mod. */ |
581 | if (s.high < 0) |
582 | mod.low += 1; |
583 | |
584 | /* Shift left quo_s by 1 bit. */ |
585 | quo_s = quo_s.lshift (count: 1); |
586 | |
587 | /* Try to calculate (mod - pos_b). */ |
588 | temp = mod - pos_b; |
589 | |
590 | if (leftmost_mod == 1 || mod.ucmp (b: pos_b) != -1) |
591 | { |
592 | quo_s.low += 1; |
593 | mod = temp; |
594 | } |
595 | |
596 | /* Shift left s by 1 bit. */ |
597 | s = s.lshift (count: 1); |
598 | |
599 | } |
600 | |
601 | if (num_of_neg == 1) |
602 | { |
603 | quo_s = -quo_s; |
604 | if (quo_s.high == 0 && quo_s.low == 0) |
605 | quo_r = -quo_r; |
606 | else |
607 | { |
608 | quo_r.low = ~quo_r.low; |
609 | quo_r.high = ~quo_r.high; |
610 | } |
611 | } |
612 | |
613 | f->data = quo_s; |
614 | overflow_p = fixed_saturate2 (mode: f->mode, a_high: quo_r, a_low: quo_s, f: &f->data, sat_p); |
615 | } |
616 | |
617 | f->data = f->data.ext (prec: (!unsigned_p) + i_f_bits, uns: unsigned_p); |
618 | return overflow_p; |
619 | } |
620 | |
621 | /* Calculate F = A << B if LEFT_P. Otherwise, F = A >> B. |
622 | If SAT_P, saturate the result to the max or the min. |
623 | Return true, if !SAT_P and overflow. */ |
624 | |
625 | static bool |
626 | do_fixed_shift (FIXED_VALUE_TYPE *f, const FIXED_VALUE_TYPE *a, |
627 | const FIXED_VALUE_TYPE *b, bool left_p, bool sat_p) |
628 | { |
629 | bool overflow_p = false; |
630 | bool unsigned_p = UNSIGNED_FIXED_POINT_MODE_P (a->mode); |
631 | int i_f_bits = GET_MODE_IBIT (a->mode) + GET_MODE_FBIT (a->mode); |
632 | f->mode = a->mode; |
633 | |
634 | if (b->data.low == 0) |
635 | { |
636 | f->data = a->data; |
637 | return overflow_p; |
638 | } |
639 | |
640 | if (GET_MODE_PRECISION (mode: f->mode) <= HOST_BITS_PER_WIDE_INT || (!left_p)) |
641 | { |
642 | f->data = a->data.lshift (count: left_p ? b->data.low : -b->data.low, |
643 | HOST_BITS_PER_DOUBLE_INT, arith: !unsigned_p); |
644 | if (left_p) /* Only left shift saturates. */ |
645 | overflow_p = fixed_saturate1 (mode: f->mode, a: f->data, f: &f->data, sat_p); |
646 | } |
647 | else /* We need two double_int to store the left-shift result. */ |
648 | { |
649 | double_int temp_high, temp_low; |
650 | if (b->data.low == HOST_BITS_PER_DOUBLE_INT) |
651 | { |
652 | temp_high = a->data; |
653 | temp_low.high = 0; |
654 | temp_low.low = 0; |
655 | } |
656 | else |
657 | { |
658 | temp_low = a->data.lshift (count: b->data.low, |
659 | HOST_BITS_PER_DOUBLE_INT, arith: !unsigned_p); |
660 | /* Logical shift right to temp_high. */ |
661 | temp_high = a->data.llshift (count: b->data.low - HOST_BITS_PER_DOUBLE_INT, |
662 | HOST_BITS_PER_DOUBLE_INT); |
663 | } |
664 | if (!unsigned_p && a->data.high < 0) /* Signed-extend temp_high. */ |
665 | temp_high = temp_high.ext (prec: b->data.low, uns: unsigned_p); |
666 | f->data = temp_low; |
667 | overflow_p = fixed_saturate2 (mode: f->mode, a_high: temp_high, a_low: temp_low, f: &f->data, |
668 | sat_p); |
669 | } |
670 | f->data = f->data.ext (prec: (!unsigned_p) + i_f_bits, uns: unsigned_p); |
671 | return overflow_p; |
672 | } |
673 | |
674 | /* Calculate F = -A. |
675 | If SAT_P, saturate the result to the max or the min. |
676 | Return true, if !SAT_P and overflow. */ |
677 | |
678 | static bool |
679 | do_fixed_neg (FIXED_VALUE_TYPE *f, const FIXED_VALUE_TYPE *a, bool sat_p) |
680 | { |
681 | bool overflow_p = false; |
682 | bool unsigned_p = UNSIGNED_FIXED_POINT_MODE_P (a->mode); |
683 | int i_f_bits = GET_MODE_IBIT (a->mode) + GET_MODE_FBIT (a->mode); |
684 | f->mode = a->mode; |
685 | f->data = -a->data; |
686 | f->data = f->data.ext (prec: (!unsigned_p) + i_f_bits, uns: unsigned_p); |
687 | |
688 | if (unsigned_p) /* Unsigned type. */ |
689 | { |
690 | if (f->data.low != 0 || f->data.high != 0) |
691 | { |
692 | if (sat_p) |
693 | { |
694 | f->data.low = 0; |
695 | f->data.high = 0; |
696 | } |
697 | else |
698 | overflow_p = true; |
699 | } |
700 | } |
701 | else /* Signed type. */ |
702 | { |
703 | if (!(f->data.high == 0 && f->data.low == 0) |
704 | && f->data.high == a->data.high && f->data.low == a->data.low ) |
705 | { |
706 | if (sat_p) |
707 | { |
708 | /* Saturate to the maximum by subtracting f->data by one. */ |
709 | f->data.low = -1; |
710 | f->data.high = -1; |
711 | f->data = f->data.zext (prec: i_f_bits); |
712 | } |
713 | else |
714 | overflow_p = true; |
715 | } |
716 | } |
717 | return overflow_p; |
718 | } |
719 | |
720 | /* Perform the binary or unary operation described by CODE. |
721 | Note that OP0 and OP1 must have the same mode for binary operators. |
722 | For a unary operation, leave OP1 NULL. |
723 | Return true, if !SAT_P and overflow. */ |
724 | |
725 | bool |
726 | fixed_arithmetic (FIXED_VALUE_TYPE *f, int icode, const FIXED_VALUE_TYPE *op0, |
727 | const FIXED_VALUE_TYPE *op1, bool sat_p) |
728 | { |
729 | switch (icode) |
730 | { |
731 | case NEGATE_EXPR: |
732 | return do_fixed_neg (f, a: op0, sat_p); |
733 | |
734 | case PLUS_EXPR: |
735 | gcc_assert (op0->mode == op1->mode); |
736 | return do_fixed_add (f, a: op0, b: op1, subtract_p: false, sat_p); |
737 | |
738 | case MINUS_EXPR: |
739 | gcc_assert (op0->mode == op1->mode); |
740 | return do_fixed_add (f, a: op0, b: op1, subtract_p: true, sat_p); |
741 | |
742 | case MULT_EXPR: |
743 | gcc_assert (op0->mode == op1->mode); |
744 | return do_fixed_multiply (f, a: op0, b: op1, sat_p); |
745 | |
746 | case TRUNC_DIV_EXPR: |
747 | gcc_assert (op0->mode == op1->mode); |
748 | return do_fixed_divide (f, a: op0, b: op1, sat_p); |
749 | |
750 | case LSHIFT_EXPR: |
751 | return do_fixed_shift (f, a: op0, b: op1, left_p: true, sat_p); |
752 | |
753 | case RSHIFT_EXPR: |
754 | return do_fixed_shift (f, a: op0, b: op1, left_p: false, sat_p); |
755 | |
756 | default: |
757 | gcc_unreachable (); |
758 | } |
759 | } |
760 | |
761 | /* Compare fixed-point values by tree_code. |
762 | Note that OP0 and OP1 must have the same mode. */ |
763 | |
764 | bool |
765 | fixed_compare (int icode, const FIXED_VALUE_TYPE *op0, |
766 | const FIXED_VALUE_TYPE *op1) |
767 | { |
768 | enum tree_code code = (enum tree_code) icode; |
769 | gcc_assert (op0->mode == op1->mode); |
770 | |
771 | switch (code) |
772 | { |
773 | case NE_EXPR: |
774 | return op0->data != op1->data; |
775 | |
776 | case EQ_EXPR: |
777 | return op0->data == op1->data; |
778 | |
779 | case LT_EXPR: |
780 | return op0->data.cmp (b: op1->data, |
781 | UNSIGNED_FIXED_POINT_MODE_P (op0->mode)) == -1; |
782 | |
783 | case LE_EXPR: |
784 | return op0->data.cmp (b: op1->data, |
785 | UNSIGNED_FIXED_POINT_MODE_P (op0->mode)) != 1; |
786 | |
787 | case GT_EXPR: |
788 | return op0->data.cmp (b: op1->data, |
789 | UNSIGNED_FIXED_POINT_MODE_P (op0->mode)) == 1; |
790 | |
791 | case GE_EXPR: |
792 | return op0->data.cmp (b: op1->data, |
793 | UNSIGNED_FIXED_POINT_MODE_P (op0->mode)) != -1; |
794 | |
795 | default: |
796 | gcc_unreachable (); |
797 | } |
798 | } |
799 | |
800 | /* Extend or truncate to a new mode. |
801 | If SAT_P, saturate the result to the max or the min. |
802 | Return true, if !SAT_P and overflow. */ |
803 | |
804 | bool |
805 | fixed_convert (FIXED_VALUE_TYPE *f, scalar_mode mode, |
806 | const FIXED_VALUE_TYPE *a, bool sat_p) |
807 | { |
808 | bool overflow_p = false; |
809 | if (mode == a->mode) |
810 | { |
811 | *f = *a; |
812 | return overflow_p; |
813 | } |
814 | |
815 | if (GET_MODE_FBIT (mode) > GET_MODE_FBIT (a->mode)) |
816 | { |
817 | /* Left shift a to temp_high, temp_low based on a->mode. */ |
818 | double_int temp_high, temp_low; |
819 | int amount = GET_MODE_FBIT (mode) - GET_MODE_FBIT (a->mode); |
820 | temp_low = a->data.lshift (count: amount, |
821 | HOST_BITS_PER_DOUBLE_INT, |
822 | SIGNED_FIXED_POINT_MODE_P (a->mode)); |
823 | /* Logical shift right to temp_high. */ |
824 | temp_high = a->data.llshift (count: amount - HOST_BITS_PER_DOUBLE_INT, |
825 | HOST_BITS_PER_DOUBLE_INT); |
826 | if (SIGNED_FIXED_POINT_MODE_P (a->mode) |
827 | && a->data.high < 0) /* Signed-extend temp_high. */ |
828 | temp_high = temp_high.sext (prec: amount); |
829 | f->mode = mode; |
830 | f->data = temp_low; |
831 | if (SIGNED_FIXED_POINT_MODE_P (a->mode) == |
832 | SIGNED_FIXED_POINT_MODE_P (f->mode)) |
833 | overflow_p = fixed_saturate2 (mode: f->mode, a_high: temp_high, a_low: temp_low, f: &f->data, |
834 | sat_p); |
835 | else |
836 | { |
837 | /* Take care of the cases when converting between signed and |
838 | unsigned. */ |
839 | if (SIGNED_FIXED_POINT_MODE_P (a->mode)) |
840 | { |
841 | /* Signed -> Unsigned. */ |
842 | if (a->data.high < 0) |
843 | { |
844 | if (sat_p) |
845 | { |
846 | f->data.low = 0; /* Set to zero. */ |
847 | f->data.high = 0; /* Set to zero. */ |
848 | } |
849 | else |
850 | overflow_p = true; |
851 | } |
852 | else |
853 | overflow_p = fixed_saturate2 (mode: f->mode, a_high: temp_high, a_low: temp_low, |
854 | f: &f->data, sat_p); |
855 | } |
856 | else |
857 | { |
858 | /* Unsigned -> Signed. */ |
859 | if (temp_high.high < 0) |
860 | { |
861 | if (sat_p) |
862 | { |
863 | /* Set to maximum. */ |
864 | f->data.low = -1; /* Set to all ones. */ |
865 | f->data.high = -1; /* Set to all ones. */ |
866 | f->data = f->data.zext (GET_MODE_FBIT (f->mode) |
867 | + GET_MODE_IBIT (f->mode)); |
868 | /* Clear the sign. */ |
869 | } |
870 | else |
871 | overflow_p = true; |
872 | } |
873 | else |
874 | overflow_p = fixed_saturate2 (mode: f->mode, a_high: temp_high, a_low: temp_low, |
875 | f: &f->data, sat_p); |
876 | } |
877 | } |
878 | } |
879 | else |
880 | { |
881 | /* Right shift a to temp based on a->mode. */ |
882 | double_int temp; |
883 | temp = a->data.lshift (GET_MODE_FBIT (mode) - GET_MODE_FBIT (a->mode), |
884 | HOST_BITS_PER_DOUBLE_INT, |
885 | SIGNED_FIXED_POINT_MODE_P (a->mode)); |
886 | f->mode = mode; |
887 | f->data = temp; |
888 | if (SIGNED_FIXED_POINT_MODE_P (a->mode) == |
889 | SIGNED_FIXED_POINT_MODE_P (f->mode)) |
890 | overflow_p = fixed_saturate1 (mode: f->mode, a: f->data, f: &f->data, sat_p); |
891 | else |
892 | { |
893 | /* Take care of the cases when converting between signed and |
894 | unsigned. */ |
895 | if (SIGNED_FIXED_POINT_MODE_P (a->mode)) |
896 | { |
897 | /* Signed -> Unsigned. */ |
898 | if (a->data.high < 0) |
899 | { |
900 | if (sat_p) |
901 | { |
902 | f->data.low = 0; /* Set to zero. */ |
903 | f->data.high = 0; /* Set to zero. */ |
904 | } |
905 | else |
906 | overflow_p = true; |
907 | } |
908 | else |
909 | overflow_p = fixed_saturate1 (mode: f->mode, a: f->data, f: &f->data, |
910 | sat_p); |
911 | } |
912 | else |
913 | { |
914 | /* Unsigned -> Signed. */ |
915 | if (temp.high < 0) |
916 | { |
917 | if (sat_p) |
918 | { |
919 | /* Set to maximum. */ |
920 | f->data.low = -1; /* Set to all ones. */ |
921 | f->data.high = -1; /* Set to all ones. */ |
922 | f->data = f->data.zext (GET_MODE_FBIT (f->mode) |
923 | + GET_MODE_IBIT (f->mode)); |
924 | /* Clear the sign. */ |
925 | } |
926 | else |
927 | overflow_p = true; |
928 | } |
929 | else |
930 | overflow_p = fixed_saturate1 (mode: f->mode, a: f->data, f: &f->data, |
931 | sat_p); |
932 | } |
933 | } |
934 | } |
935 | |
936 | f->data = f->data.ext (SIGNED_FIXED_POINT_MODE_P (f->mode) |
937 | + GET_MODE_FBIT (f->mode) |
938 | + GET_MODE_IBIT (f->mode), |
939 | UNSIGNED_FIXED_POINT_MODE_P (f->mode)); |
940 | return overflow_p; |
941 | } |
942 | |
943 | /* Convert to a new fixed-point mode from an integer. |
944 | If UNSIGNED_P, this integer is unsigned. |
945 | If SAT_P, saturate the result to the max or the min. |
946 | Return true, if !SAT_P and overflow. */ |
947 | |
948 | bool |
949 | fixed_convert_from_int (FIXED_VALUE_TYPE *f, scalar_mode mode, |
950 | double_int a, bool unsigned_p, bool sat_p) |
951 | { |
952 | bool overflow_p = false; |
953 | /* Left shift a to temp_high, temp_low. */ |
954 | double_int temp_high, temp_low; |
955 | int amount = GET_MODE_FBIT (mode); |
956 | if (amount == HOST_BITS_PER_DOUBLE_INT) |
957 | { |
958 | temp_high = a; |
959 | temp_low.low = 0; |
960 | temp_low.high = 0; |
961 | } |
962 | else |
963 | { |
964 | temp_low = a.llshift (count: amount, HOST_BITS_PER_DOUBLE_INT); |
965 | |
966 | /* Logical shift right to temp_high. */ |
967 | temp_high = a.llshift (count: amount - HOST_BITS_PER_DOUBLE_INT, |
968 | HOST_BITS_PER_DOUBLE_INT); |
969 | } |
970 | if (!unsigned_p && a.high < 0) /* Signed-extend temp_high. */ |
971 | temp_high = temp_high.sext (prec: amount); |
972 | |
973 | f->mode = mode; |
974 | f->data = temp_low; |
975 | |
976 | if (unsigned_p == UNSIGNED_FIXED_POINT_MODE_P (f->mode)) |
977 | overflow_p = fixed_saturate2 (mode: f->mode, a_high: temp_high, a_low: temp_low, f: &f->data, |
978 | sat_p); |
979 | else |
980 | { |
981 | /* Take care of the cases when converting between signed and unsigned. */ |
982 | if (!unsigned_p) |
983 | { |
984 | /* Signed -> Unsigned. */ |
985 | if (a.high < 0) |
986 | { |
987 | if (sat_p) |
988 | { |
989 | f->data.low = 0; /* Set to zero. */ |
990 | f->data.high = 0; /* Set to zero. */ |
991 | } |
992 | else |
993 | overflow_p = true; |
994 | } |
995 | else |
996 | overflow_p = fixed_saturate2 (mode: f->mode, a_high: temp_high, a_low: temp_low, |
997 | f: &f->data, sat_p); |
998 | } |
999 | else |
1000 | { |
1001 | /* Unsigned -> Signed. */ |
1002 | if (temp_high.high < 0) |
1003 | { |
1004 | if (sat_p) |
1005 | { |
1006 | /* Set to maximum. */ |
1007 | f->data.low = -1; /* Set to all ones. */ |
1008 | f->data.high = -1; /* Set to all ones. */ |
1009 | f->data = f->data.zext (GET_MODE_FBIT (f->mode) |
1010 | + GET_MODE_IBIT (f->mode)); |
1011 | /* Clear the sign. */ |
1012 | } |
1013 | else |
1014 | overflow_p = true; |
1015 | } |
1016 | else |
1017 | overflow_p = fixed_saturate2 (mode: f->mode, a_high: temp_high, a_low: temp_low, |
1018 | f: &f->data, sat_p); |
1019 | } |
1020 | } |
1021 | f->data = f->data.ext (SIGNED_FIXED_POINT_MODE_P (f->mode) |
1022 | + GET_MODE_FBIT (f->mode) |
1023 | + GET_MODE_IBIT (f->mode), |
1024 | UNSIGNED_FIXED_POINT_MODE_P (f->mode)); |
1025 | return overflow_p; |
1026 | } |
1027 | |
1028 | /* Convert to a new fixed-point mode from a real. |
1029 | If SAT_P, saturate the result to the max or the min. |
1030 | Return true, if !SAT_P and overflow. */ |
1031 | |
1032 | bool |
1033 | fixed_convert_from_real (FIXED_VALUE_TYPE *f, scalar_mode mode, |
1034 | const REAL_VALUE_TYPE *a, bool sat_p) |
1035 | { |
1036 | bool overflow_p = false; |
1037 | REAL_VALUE_TYPE real_value, fixed_value, base_value; |
1038 | bool unsigned_p = UNSIGNED_FIXED_POINT_MODE_P (mode); |
1039 | int i_f_bits = GET_MODE_IBIT (mode) + GET_MODE_FBIT (mode); |
1040 | unsigned int fbit = GET_MODE_FBIT (mode); |
1041 | enum fixed_value_range_code temp; |
1042 | bool fail; |
1043 | |
1044 | real_value = *a; |
1045 | f->mode = mode; |
1046 | real_2expN (&base_value, fbit, VOIDmode); |
1047 | real_arithmetic (&fixed_value, MULT_EXPR, &real_value, &base_value); |
1048 | |
1049 | wide_int w = real_to_integer (&fixed_value, &fail, |
1050 | GET_MODE_PRECISION (mode)); |
1051 | f->data.low = w.ulow (); |
1052 | f->data.high = w.elt (i: 1); |
1053 | temp = check_real_for_fixed_mode (real_value: &real_value, mode); |
1054 | if (temp == FIXED_UNDERFLOW) /* Minimum. */ |
1055 | { |
1056 | if (sat_p) |
1057 | { |
1058 | if (unsigned_p) |
1059 | { |
1060 | f->data.low = 0; |
1061 | f->data.high = 0; |
1062 | } |
1063 | else |
1064 | { |
1065 | f->data.low = 1; |
1066 | f->data.high = 0; |
1067 | f->data = f->data.alshift (count: i_f_bits, HOST_BITS_PER_DOUBLE_INT); |
1068 | f->data = f->data.sext (prec: 1 + i_f_bits); |
1069 | } |
1070 | } |
1071 | else |
1072 | overflow_p = true; |
1073 | } |
1074 | else if (temp == FIXED_GT_MAX_EPS || temp == FIXED_MAX_EPS) /* Maximum. */ |
1075 | { |
1076 | if (sat_p) |
1077 | { |
1078 | f->data.low = -1; |
1079 | f->data.high = -1; |
1080 | f->data = f->data.zext (prec: i_f_bits); |
1081 | } |
1082 | else |
1083 | overflow_p = true; |
1084 | } |
1085 | f->data = f->data.ext (prec: (!unsigned_p) + i_f_bits, uns: unsigned_p); |
1086 | return overflow_p; |
1087 | } |
1088 | |
1089 | /* Convert to a new real mode from a fixed-point. */ |
1090 | |
1091 | void |
1092 | real_convert_from_fixed (REAL_VALUE_TYPE *r, scalar_mode mode, |
1093 | const FIXED_VALUE_TYPE *f) |
1094 | { |
1095 | REAL_VALUE_TYPE base_value, fixed_value, real_value; |
1096 | |
1097 | signop sgn = UNSIGNED_FIXED_POINT_MODE_P (f->mode) ? UNSIGNED : SIGNED; |
1098 | real_2expN (&base_value, GET_MODE_FBIT (f->mode), VOIDmode); |
1099 | real_from_integer (&fixed_value, VOIDmode, |
1100 | wide_int::from (x: f->data, precision: GET_MODE_PRECISION (mode: f->mode), |
1101 | sgn), sgn); |
1102 | real_arithmetic (&real_value, RDIV_EXPR, &fixed_value, &base_value); |
1103 | real_convert (r, mode, &real_value); |
1104 | } |
1105 | |
1106 | /* Determine whether a fixed-point value F is negative. */ |
1107 | |
1108 | bool |
1109 | fixed_isneg (const FIXED_VALUE_TYPE *f) |
1110 | { |
1111 | if (SIGNED_FIXED_POINT_MODE_P (f->mode)) |
1112 | { |
1113 | int i_f_bits = GET_MODE_IBIT (f->mode) + GET_MODE_FBIT (f->mode); |
1114 | int sign_bit = get_fixed_sign_bit (a: f->data, i_f_bits); |
1115 | if (sign_bit == 1) |
1116 | return true; |
1117 | } |
1118 | |
1119 | return false; |
1120 | } |
1121 | |