1 /* Fixed-point arithmetic support.
2 Copyright (C) 2006, 2007, 2008, 2009, 2010 Free Software Foundation, Inc.
4 This file is part of GCC.
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
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
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/>. */
22 #include "coretypes.h"
25 #include "diagnostic-core.h"
27 /* Compare two fixed objects for bitwise identity. */
30 fixed_identical (const FIXED_VALUE_TYPE *a, const FIXED_VALUE_TYPE *b)
32 return (a->mode == b->mode
33 && a->data.high == b->data.high
34 && a->data.low == b->data.low);
37 /* Calculate a hash value. */
40 fixed_hash (const FIXED_VALUE_TYPE *f)
42 return (unsigned int) (f->data.low ^ f->data.high);
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. */
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. */
61 static enum fixed_value_range_code
62 check_real_for_fixed_mode (REAL_VALUE_TYPE *real_value, enum machine_mode mode)
64 REAL_VALUE_TYPE max_value, min_value, epsilon_value;
66 real_2expN (&max_value, GET_MODE_IBIT (mode), mode);
67 real_2expN (&epsilon_value, -GET_MODE_FBIT (mode), mode);
69 if (SIGNED_FIXED_POINT_MODE_P (mode))
70 min_value = real_value_negate (&max_value);
72 real_from_string (&min_value, "0.0");
74 if (real_compare (LT_EXPR, real_value, &min_value))
75 return FIXED_UNDERFLOW;
76 if (real_compare (EQ_EXPR, real_value, &max_value))
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;
84 /* Initialize from a decimal or hexadecimal string. */
87 fixed_from_string (FIXED_VALUE_TYPE *f, const char *str, enum machine_mode mode)
89 REAL_VALUE_TYPE real_value, fixed_value, base_value;
91 enum fixed_value_range_code temp;
94 fbit = GET_MODE_FBIT (mode);
96 real_from_string (&real_value, str);
97 temp = check_real_for_fixed_mode (&real_value, f->mode);
98 /* We don't want to warn the case when the _Fract value is 1.0. */
99 if (temp == FIXED_UNDERFLOW
100 || temp == FIXED_GT_MAX_EPS
101 || (temp == FIXED_MAX_EPS && ALL_ACCUM_MODE_P (f->mode)))
102 warning (OPT_Woverflow,
103 "large fixed-point constant implicitly truncated to fixed-point type");
104 real_2expN (&base_value, fbit, mode);
105 real_arithmetic (&fixed_value, MULT_EXPR, &real_value, &base_value);
106 real_to_integer2 ((HOST_WIDE_INT *)&f->data.low, &f->data.high,
109 if (temp == FIXED_MAX_EPS && ALL_FRACT_MODE_P (f->mode))
111 /* From the spec, we need to evaluate 1 to the maximal value. */
114 f->data = double_int_ext (f->data,
115 GET_MODE_FBIT (f->mode)
116 + GET_MODE_IBIT (f->mode), 1);
119 f->data = double_int_ext (f->data,
120 SIGNED_FIXED_POINT_MODE_P (f->mode)
121 + GET_MODE_FBIT (f->mode)
122 + GET_MODE_IBIT (f->mode),
123 UNSIGNED_FIXED_POINT_MODE_P (f->mode));
126 /* Render F as a decimal floating point constant. */
129 fixed_to_decimal (char *str, const FIXED_VALUE_TYPE *f_orig,
132 REAL_VALUE_TYPE real_value, base_value, fixed_value;
134 real_2expN (&base_value, GET_MODE_FBIT (f_orig->mode), f_orig->mode);
135 real_from_integer (&real_value, VOIDmode, f_orig->data.low, f_orig->data.high,
136 UNSIGNED_FIXED_POINT_MODE_P (f_orig->mode));
137 real_arithmetic (&fixed_value, RDIV_EXPR, &real_value, &base_value);
138 real_to_decimal (str, &fixed_value, buf_size, 0, 1);
141 /* If SAT_P, saturate A to the maximum or the minimum, and save to *F based on
142 the machine mode MODE.
143 Do not modify *F otherwise.
144 This function assumes the width of double_int is greater than the width
145 of the fixed-point value (the sum of a possible sign bit, possible ibits,
147 Return true, if !SAT_P and overflow. */
150 fixed_saturate1 (enum machine_mode mode, double_int a, double_int *f,
153 bool overflow_p = false;
154 bool unsigned_p = UNSIGNED_FIXED_POINT_MODE_P (mode);
155 int i_f_bits = GET_MODE_IBIT (mode) + GET_MODE_FBIT (mode);
157 if (unsigned_p) /* Unsigned type. */
162 max = double_int_ext (max, i_f_bits, 1);
163 if (double_int_cmp (a, max, 1) == 1)
171 else /* Signed type. */
176 max = double_int_ext (max, i_f_bits, 1);
179 lshift_double (min.low, min.high, i_f_bits,
180 HOST_BITS_PER_DOUBLE_INT,
181 &min.low, &min.high, 1);
182 min = double_int_ext (min, 1 + i_f_bits, 0);
183 if (double_int_cmp (a, max, 0) == 1)
190 else if (double_int_cmp (a, min, 0) == -1)
201 /* If SAT_P, saturate {A_HIGH, A_LOW} to the maximum or the minimum, and
202 save to *F based on the machine mode MODE.
203 Do not modify *F otherwise.
204 This function assumes the width of two double_int is greater than the width
205 of the fixed-point value (the sum of a possible sign bit, possible ibits,
207 Return true, if !SAT_P and overflow. */
210 fixed_saturate2 (enum machine_mode mode, double_int a_high, double_int a_low,
211 double_int *f, bool sat_p)
213 bool overflow_p = false;
214 bool unsigned_p = UNSIGNED_FIXED_POINT_MODE_P (mode);
215 int i_f_bits = GET_MODE_IBIT (mode) + GET_MODE_FBIT (mode);
217 if (unsigned_p) /* Unsigned type. */
219 double_int max_r, max_s;
224 max_s = double_int_ext (max_s, i_f_bits, 1);
225 if (double_int_cmp (a_high, max_r, 1) == 1
226 || (double_int_equal_p (a_high, max_r) &&
227 double_int_cmp (a_low, max_s, 1) == 1))
235 else /* Signed type. */
237 double_int max_r, max_s, min_r, min_s;
242 max_s = double_int_ext (max_s, i_f_bits, 1);
247 lshift_double (min_s.low, min_s.high, i_f_bits,
248 HOST_BITS_PER_DOUBLE_INT,
249 &min_s.low, &min_s.high, 1);
250 min_s = double_int_ext (min_s, 1 + i_f_bits, 0);
251 if (double_int_cmp (a_high, max_r, 0) == 1
252 || (double_int_equal_p (a_high, max_r) &&
253 double_int_cmp (a_low, max_s, 1) == 1))
260 else if (double_int_cmp (a_high, min_r, 0) == -1
261 || (double_int_equal_p (a_high, min_r) &&
262 double_int_cmp (a_low, min_s, 1) == -1))
273 /* Return the sign bit based on I_F_BITS. */
276 get_fixed_sign_bit (double_int a, int i_f_bits)
278 if (i_f_bits < HOST_BITS_PER_WIDE_INT)
279 return (a.low >> i_f_bits) & 1;
281 return (a.high >> (i_f_bits - HOST_BITS_PER_WIDE_INT)) & 1;
284 /* Calculate F = A + (SUBTRACT_P ? -B : B).
285 If SAT_P, saturate the result to the max or the min.
286 Return true, if !SAT_P and overflow. */
289 do_fixed_add (FIXED_VALUE_TYPE *f, const FIXED_VALUE_TYPE *a,
290 const FIXED_VALUE_TYPE *b, bool subtract_p, bool sat_p)
292 bool overflow_p = false;
297 /* This was a conditional expression but it triggered a bug in
300 temp = double_int_neg (b->data);
304 unsigned_p = UNSIGNED_FIXED_POINT_MODE_P (a->mode);
305 i_f_bits = GET_MODE_IBIT (a->mode) + GET_MODE_FBIT (a->mode);
307 f->data = double_int_add (a->data, temp);
308 if (unsigned_p) /* Unsigned type. */
310 if (subtract_p) /* Unsigned subtraction. */
312 if (double_int_cmp (a->data, b->data, 1) == -1)
323 else /* Unsigned addition. */
325 f->data = double_int_ext (f->data, i_f_bits, 1);
326 if (double_int_cmp (f->data, a->data, 1) == -1
327 || double_int_cmp (f->data, b->data, 1) == -1)
339 else /* Signed type. */
342 && (get_fixed_sign_bit (a->data, i_f_bits)
343 == get_fixed_sign_bit (b->data, i_f_bits))
344 && (get_fixed_sign_bit (a->data, i_f_bits)
345 != get_fixed_sign_bit (f->data, i_f_bits)))
347 && (get_fixed_sign_bit (a->data, i_f_bits)
348 != get_fixed_sign_bit (b->data, i_f_bits))
349 && (get_fixed_sign_bit (a->data, i_f_bits)
350 != get_fixed_sign_bit (f->data, i_f_bits))))
356 lshift_double (f->data.low, f->data.high, i_f_bits,
357 HOST_BITS_PER_DOUBLE_INT,
358 &f->data.low, &f->data.high, 1);
359 if (get_fixed_sign_bit (a->data, i_f_bits) == 0)
364 f->data = double_int_sub (f->data, one);
371 f->data = double_int_ext (f->data, (!unsigned_p) + i_f_bits, unsigned_p);
375 /* Calculate F = A * B.
376 If SAT_P, saturate the result to the max or the min.
377 Return true, if !SAT_P and overflow. */
380 do_fixed_multiply (FIXED_VALUE_TYPE *f, const FIXED_VALUE_TYPE *a,
381 const FIXED_VALUE_TYPE *b, bool sat_p)
383 bool overflow_p = false;
384 bool unsigned_p = UNSIGNED_FIXED_POINT_MODE_P (a->mode);
385 int i_f_bits = GET_MODE_IBIT (a->mode) + GET_MODE_FBIT (a->mode);
387 if (GET_MODE_PRECISION (f->mode) <= HOST_BITS_PER_WIDE_INT)
389 f->data = double_int_mul (a->data, b->data);
390 lshift_double (f->data.low, f->data.high,
391 (-GET_MODE_FBIT (f->mode)),
392 HOST_BITS_PER_DOUBLE_INT,
393 &f->data.low, &f->data.high, !unsigned_p);
394 overflow_p = fixed_saturate1 (f->mode, f->data, &f->data, sat_p);
398 /* The result of multiplication expands to two double_int. */
399 double_int a_high, a_low, b_high, b_low;
400 double_int high_high, high_low, low_high, low_low;
401 double_int r, s, temp1, temp2;
404 /* Decompose a and b to four double_int. */
405 a_high.low = a->data.high;
407 a_low.low = a->data.low;
409 b_high.low = b->data.high;
411 b_low.low = b->data.low;
414 /* Perform four multiplications. */
415 low_low = double_int_mul (a_low, b_low);
416 low_high = double_int_mul (a_low, b_high);
417 high_low = double_int_mul (a_high, b_low);
418 high_high = double_int_mul (a_high, b_high);
420 /* Accumulate four results to {r, s}. */
421 temp1.high = high_low.low;
423 s = double_int_add (low_low, temp1);
424 if (double_int_cmp (s, low_low, 1) == -1
425 || double_int_cmp (s, temp1, 1) == -1)
426 carry ++; /* Carry */
429 temp2.high = low_high.low;
431 s = double_int_add (temp1, temp2);
432 if (double_int_cmp (s, temp1, 1) == -1
433 || double_int_cmp (s, temp2, 1) == -1)
434 carry ++; /* Carry */
436 temp1.low = high_low.high;
438 r = double_int_add (high_high, temp1);
439 temp1.low = low_high.high;
441 r = double_int_add (r, temp1);
444 r = double_int_add (r, temp1);
446 /* We need to subtract b from r, if a < 0. */
447 if (!unsigned_p && a->data.high < 0)
448 r = double_int_sub (r, b->data);
449 /* We need to subtract a from r, if b < 0. */
450 if (!unsigned_p && b->data.high < 0)
451 r = double_int_sub (r, a->data);
453 /* Shift right the result by FBIT. */
454 if (GET_MODE_FBIT (f->mode) == HOST_BITS_PER_DOUBLE_INT)
469 f->data.high = s.high;
473 lshift_double (s.low, s.high,
474 (-GET_MODE_FBIT (f->mode)),
475 HOST_BITS_PER_DOUBLE_INT,
477 lshift_double (r.low, r.high,
478 (HOST_BITS_PER_DOUBLE_INT
479 - GET_MODE_FBIT (f->mode)),
480 HOST_BITS_PER_DOUBLE_INT,
481 &f->data.low, &f->data.high, 0);
482 f->data.low = f->data.low | s.low;
483 f->data.high = f->data.high | s.high;
485 s.high = f->data.high;
486 lshift_double (r.low, r.high,
487 (-GET_MODE_FBIT (f->mode)),
488 HOST_BITS_PER_DOUBLE_INT,
489 &r.low, &r.high, !unsigned_p);
492 overflow_p = fixed_saturate2 (f->mode, r, s, &f->data, sat_p);
495 f->data = double_int_ext (f->data, (!unsigned_p) + i_f_bits, unsigned_p);
499 /* Calculate F = A / B.
500 If SAT_P, saturate the result to the max or the min.
501 Return true, if !SAT_P and overflow. */
504 do_fixed_divide (FIXED_VALUE_TYPE *f, const FIXED_VALUE_TYPE *a,
505 const FIXED_VALUE_TYPE *b, bool sat_p)
507 bool overflow_p = false;
508 bool unsigned_p = UNSIGNED_FIXED_POINT_MODE_P (a->mode);
509 int i_f_bits = GET_MODE_IBIT (a->mode) + GET_MODE_FBIT (a->mode);
511 if (GET_MODE_PRECISION (f->mode) <= HOST_BITS_PER_WIDE_INT)
513 lshift_double (a->data.low, a->data.high,
514 GET_MODE_FBIT (f->mode),
515 HOST_BITS_PER_DOUBLE_INT,
516 &f->data.low, &f->data.high, !unsigned_p);
517 f->data = double_int_div (f->data, b->data, unsigned_p, TRUNC_DIV_EXPR);
518 overflow_p = fixed_saturate1 (f->mode, f->data, &f->data, sat_p);
522 double_int pos_a, pos_b, r, s;
523 double_int quo_r, quo_s, mod, temp;
527 /* If a < 0, negate a. */
528 if (!unsigned_p && a->data.high < 0)
530 pos_a = double_int_neg (a->data);
536 /* If b < 0, negate b. */
537 if (!unsigned_p && b->data.high < 0)
539 pos_b = double_int_neg (b->data);
545 /* Left shift pos_a to {r, s} by FBIT. */
546 if (GET_MODE_FBIT (f->mode) == HOST_BITS_PER_DOUBLE_INT)
554 lshift_double (pos_a.low, pos_a.high,
555 GET_MODE_FBIT (f->mode),
556 HOST_BITS_PER_DOUBLE_INT,
558 lshift_double (pos_a.low, pos_a.high,
559 - (HOST_BITS_PER_DOUBLE_INT
560 - GET_MODE_FBIT (f->mode)),
561 HOST_BITS_PER_DOUBLE_INT,
565 /* Divide r by pos_b to quo_r. The remainder is in mod. */
566 div_and_round_double (TRUNC_DIV_EXPR, 1, r.low, r.high, pos_b.low,
567 pos_b.high, &quo_r.low, &quo_r.high, &mod.low,
573 for (i = 0; i < HOST_BITS_PER_DOUBLE_INT; i++)
575 /* Record the leftmost bit of mod. */
576 int leftmost_mod = (mod.high < 0);
578 /* Shift left mod by 1 bit. */
579 lshift_double (mod.low, mod.high, 1, HOST_BITS_PER_DOUBLE_INT,
580 &mod.low, &mod.high, 0);
582 /* Test the leftmost bit of s to add to mod. */
586 /* Shift left quo_s by 1 bit. */
587 lshift_double (quo_s.low, quo_s.high, 1, HOST_BITS_PER_DOUBLE_INT,
588 &quo_s.low, &quo_s.high, 0);
590 /* Try to calculate (mod - pos_b). */
591 temp = double_int_sub (mod, pos_b);
593 if (leftmost_mod == 1 || double_int_cmp (mod, pos_b, 1) != -1)
599 /* Shift left s by 1 bit. */
600 lshift_double (s.low, s.high, 1, HOST_BITS_PER_DOUBLE_INT,
607 quo_s = double_int_neg (quo_s);
608 if (quo_s.high == 0 && quo_s.low == 0)
609 quo_r = double_int_neg (quo_r);
612 quo_r.low = ~quo_r.low;
613 quo_r.high = ~quo_r.high;
618 overflow_p = fixed_saturate2 (f->mode, quo_r, quo_s, &f->data, sat_p);
621 f->data = double_int_ext (f->data, (!unsigned_p) + i_f_bits, unsigned_p);
625 /* Calculate F = A << B if LEFT_P. Otherwise, F = A >> B.
626 If SAT_P, saturate the result to the max or the min.
627 Return true, if !SAT_P and overflow. */
630 do_fixed_shift (FIXED_VALUE_TYPE *f, const FIXED_VALUE_TYPE *a,
631 const FIXED_VALUE_TYPE *b, bool left_p, bool sat_p)
633 bool overflow_p = false;
634 bool unsigned_p = UNSIGNED_FIXED_POINT_MODE_P (a->mode);
635 int i_f_bits = GET_MODE_IBIT (a->mode) + GET_MODE_FBIT (a->mode);
638 if (b->data.low == 0)
644 if (GET_MODE_PRECISION (f->mode) <= HOST_BITS_PER_WIDE_INT || (!left_p))
646 lshift_double (a->data.low, a->data.high,
647 left_p ? b->data.low : (-b->data.low),
648 HOST_BITS_PER_DOUBLE_INT,
649 &f->data.low, &f->data.high, !unsigned_p);
650 if (left_p) /* Only left shift saturates. */
651 overflow_p = fixed_saturate1 (f->mode, f->data, &f->data, sat_p);
653 else /* We need two double_int to store the left-shift result. */
655 double_int temp_high, temp_low;
656 if (b->data.low == HOST_BITS_PER_DOUBLE_INT)
664 lshift_double (a->data.low, a->data.high,
666 HOST_BITS_PER_DOUBLE_INT,
667 &temp_low.low, &temp_low.high, !unsigned_p);
668 /* Logical shift right to temp_high. */
669 lshift_double (a->data.low, a->data.high,
670 b->data.low - HOST_BITS_PER_DOUBLE_INT,
671 HOST_BITS_PER_DOUBLE_INT,
672 &temp_high.low, &temp_high.high, 0);
674 if (!unsigned_p && a->data.high < 0) /* Signed-extend temp_high. */
675 temp_high = double_int_ext (temp_high, b->data.low, unsigned_p);
677 overflow_p = fixed_saturate2 (f->mode, temp_high, temp_low, &f->data,
680 f->data = double_int_ext (f->data, (!unsigned_p) + i_f_bits, unsigned_p);
685 If SAT_P, saturate the result to the max or the min.
686 Return true, if !SAT_P and overflow. */
689 do_fixed_neg (FIXED_VALUE_TYPE *f, const FIXED_VALUE_TYPE *a, bool sat_p)
691 bool overflow_p = false;
692 bool unsigned_p = UNSIGNED_FIXED_POINT_MODE_P (a->mode);
693 int i_f_bits = GET_MODE_IBIT (a->mode) + GET_MODE_FBIT (a->mode);
695 f->data = double_int_neg (a->data);
696 f->data = double_int_ext (f->data, (!unsigned_p) + i_f_bits, unsigned_p);
698 if (unsigned_p) /* Unsigned type. */
700 if (f->data.low != 0 || f->data.high != 0)
711 else /* Signed type. */
713 if (!(f->data.high == 0 && f->data.low == 0)
714 && f->data.high == a->data.high && f->data.low == a->data.low )
718 /* Saturate to the maximum by subtracting f->data by one. */
721 f->data = double_int_ext (f->data, i_f_bits, 1);
730 /* Perform the binary or unary operation described by CODE.
731 Note that OP0 and OP1 must have the same mode for binary operators.
732 For a unary operation, leave OP1 NULL.
733 Return true, if !SAT_P and overflow. */
736 fixed_arithmetic (FIXED_VALUE_TYPE *f, int icode, const FIXED_VALUE_TYPE *op0,
737 const FIXED_VALUE_TYPE *op1, bool sat_p)
742 return do_fixed_neg (f, op0, sat_p);
746 gcc_assert (op0->mode == op1->mode);
747 return do_fixed_add (f, op0, op1, false, sat_p);
751 gcc_assert (op0->mode == op1->mode);
752 return do_fixed_add (f, op0, op1, true, sat_p);
756 gcc_assert (op0->mode == op1->mode);
757 return do_fixed_multiply (f, op0, op1, sat_p);
761 gcc_assert (op0->mode == op1->mode);
762 return do_fixed_divide (f, op0, op1, sat_p);
766 return do_fixed_shift (f, op0, op1, true, sat_p);
770 return do_fixed_shift (f, op0, op1, false, sat_p);
779 /* Compare fixed-point values by tree_code.
780 Note that OP0 and OP1 must have the same mode. */
783 fixed_compare (int icode, const FIXED_VALUE_TYPE *op0,
784 const FIXED_VALUE_TYPE *op1)
786 enum tree_code code = (enum tree_code) icode;
787 gcc_assert (op0->mode == op1->mode);
792 return !double_int_equal_p (op0->data, op1->data);
795 return double_int_equal_p (op0->data, op1->data);
798 return double_int_cmp (op0->data, op1->data,
799 UNSIGNED_FIXED_POINT_MODE_P (op0->mode)) == -1;
802 return double_int_cmp (op0->data, op1->data,
803 UNSIGNED_FIXED_POINT_MODE_P (op0->mode)) != 1;
806 return double_int_cmp (op0->data, op1->data,
807 UNSIGNED_FIXED_POINT_MODE_P (op0->mode)) == 1;
810 return double_int_cmp (op0->data, op1->data,
811 UNSIGNED_FIXED_POINT_MODE_P (op0->mode)) != -1;
818 /* Extend or truncate to a new mode.
819 If SAT_P, saturate the result to the max or the min.
820 Return true, if !SAT_P and overflow. */
823 fixed_convert (FIXED_VALUE_TYPE *f, enum machine_mode mode,
824 const FIXED_VALUE_TYPE *a, bool sat_p)
826 bool overflow_p = false;
833 if (GET_MODE_FBIT (mode) > GET_MODE_FBIT (a->mode))
835 /* Left shift a to temp_high, temp_low based on a->mode. */
836 double_int temp_high, temp_low;
837 int amount = GET_MODE_FBIT (mode) - GET_MODE_FBIT (a->mode);
838 lshift_double (a->data.low, a->data.high,
840 HOST_BITS_PER_DOUBLE_INT,
841 &temp_low.low, &temp_low.high,
842 SIGNED_FIXED_POINT_MODE_P (a->mode));
843 /* Logical shift right to temp_high. */
844 lshift_double (a->data.low, a->data.high,
845 amount - HOST_BITS_PER_DOUBLE_INT,
846 HOST_BITS_PER_DOUBLE_INT,
847 &temp_high.low, &temp_high.high, 0);
848 if (SIGNED_FIXED_POINT_MODE_P (a->mode)
849 && a->data.high < 0) /* Signed-extend temp_high. */
850 temp_high = double_int_ext (temp_high, amount, 0);
853 if (SIGNED_FIXED_POINT_MODE_P (a->mode) ==
854 SIGNED_FIXED_POINT_MODE_P (f->mode))
855 overflow_p = fixed_saturate2 (f->mode, temp_high, temp_low, &f->data,
859 /* Take care of the cases when converting between signed and
861 if (SIGNED_FIXED_POINT_MODE_P (a->mode))
863 /* Signed -> Unsigned. */
864 if (a->data.high < 0)
868 f->data.low = 0; /* Set to zero. */
869 f->data.high = 0; /* Set to zero. */
875 overflow_p = fixed_saturate2 (f->mode, temp_high, temp_low,
880 /* Unsigned -> Signed. */
881 if (temp_high.high < 0)
885 /* Set to maximum. */
886 f->data.low = -1; /* Set to all ones. */
887 f->data.high = -1; /* Set to all ones. */
888 f->data = double_int_ext (f->data,
889 GET_MODE_FBIT (f->mode)
890 + GET_MODE_IBIT (f->mode),
891 1); /* Clear the sign. */
897 overflow_p = fixed_saturate2 (f->mode, temp_high, temp_low,
904 /* Right shift a to temp based on a->mode. */
906 lshift_double (a->data.low, a->data.high,
907 GET_MODE_FBIT (mode) - GET_MODE_FBIT (a->mode),
908 HOST_BITS_PER_DOUBLE_INT,
909 &temp.low, &temp.high,
910 SIGNED_FIXED_POINT_MODE_P (a->mode));
913 if (SIGNED_FIXED_POINT_MODE_P (a->mode) ==
914 SIGNED_FIXED_POINT_MODE_P (f->mode))
915 overflow_p = fixed_saturate1 (f->mode, f->data, &f->data, sat_p);
918 /* Take care of the cases when converting between signed and
920 if (SIGNED_FIXED_POINT_MODE_P (a->mode))
922 /* Signed -> Unsigned. */
923 if (a->data.high < 0)
927 f->data.low = 0; /* Set to zero. */
928 f->data.high = 0; /* Set to zero. */
934 overflow_p = fixed_saturate1 (f->mode, f->data, &f->data,
939 /* Unsigned -> Signed. */
944 /* Set to maximum. */
945 f->data.low = -1; /* Set to all ones. */
946 f->data.high = -1; /* Set to all ones. */
947 f->data = double_int_ext (f->data,
948 GET_MODE_FBIT (f->mode)
949 + GET_MODE_IBIT (f->mode),
950 1); /* Clear the sign. */
956 overflow_p = fixed_saturate1 (f->mode, f->data, &f->data,
962 f->data = double_int_ext (f->data,
963 SIGNED_FIXED_POINT_MODE_P (f->mode)
964 + GET_MODE_FBIT (f->mode)
965 + GET_MODE_IBIT (f->mode),
966 UNSIGNED_FIXED_POINT_MODE_P (f->mode));
970 /* Convert to a new fixed-point mode from an integer.
971 If UNSIGNED_P, this integer is unsigned.
972 If SAT_P, saturate the result to the max or the min.
973 Return true, if !SAT_P and overflow. */
976 fixed_convert_from_int (FIXED_VALUE_TYPE *f, enum machine_mode mode,
977 double_int a, bool unsigned_p, bool sat_p)
979 bool overflow_p = false;
980 /* Left shift a to temp_high, temp_low. */
981 double_int temp_high, temp_low;
982 int amount = GET_MODE_FBIT (mode);
983 if (amount == HOST_BITS_PER_DOUBLE_INT)
991 lshift_double (a.low, a.high,
993 HOST_BITS_PER_DOUBLE_INT,
994 &temp_low.low, &temp_low.high, 0);
996 /* Logical shift right to temp_high. */
997 lshift_double (a.low, a.high,
998 amount - HOST_BITS_PER_DOUBLE_INT,
999 HOST_BITS_PER_DOUBLE_INT,
1000 &temp_high.low, &temp_high.high, 0);
1002 if (!unsigned_p && a.high < 0) /* Signed-extend temp_high. */
1003 temp_high = double_int_ext (temp_high, amount, 0);
1008 if (unsigned_p == UNSIGNED_FIXED_POINT_MODE_P (f->mode))
1009 overflow_p = fixed_saturate2 (f->mode, temp_high, temp_low, &f->data,
1013 /* Take care of the cases when converting between signed and unsigned. */
1016 /* Signed -> Unsigned. */
1021 f->data.low = 0; /* Set to zero. */
1022 f->data.high = 0; /* Set to zero. */
1028 overflow_p = fixed_saturate2 (f->mode, temp_high, temp_low,
1033 /* Unsigned -> Signed. */
1034 if (temp_high.high < 0)
1038 /* Set to maximum. */
1039 f->data.low = -1; /* Set to all ones. */
1040 f->data.high = -1; /* Set to all ones. */
1041 f->data = double_int_ext (f->data,
1042 GET_MODE_FBIT (f->mode)
1043 + GET_MODE_IBIT (f->mode),
1044 1); /* Clear the sign. */
1050 overflow_p = fixed_saturate2 (f->mode, temp_high, temp_low,
1054 f->data = double_int_ext (f->data,
1055 SIGNED_FIXED_POINT_MODE_P (f->mode)
1056 + GET_MODE_FBIT (f->mode)
1057 + GET_MODE_IBIT (f->mode),
1058 UNSIGNED_FIXED_POINT_MODE_P (f->mode));
1062 /* Convert to a new fixed-point mode from a real.
1063 If SAT_P, saturate the result to the max or the min.
1064 Return true, if !SAT_P and overflow. */
1067 fixed_convert_from_real (FIXED_VALUE_TYPE *f, enum machine_mode mode,
1068 const REAL_VALUE_TYPE *a, bool sat_p)
1070 bool overflow_p = false;
1071 REAL_VALUE_TYPE real_value, fixed_value, base_value;
1072 bool unsigned_p = UNSIGNED_FIXED_POINT_MODE_P (mode);
1073 int i_f_bits = GET_MODE_IBIT (mode) + GET_MODE_FBIT (mode);
1074 unsigned int fbit = GET_MODE_FBIT (mode);
1075 enum fixed_value_range_code temp;
1079 real_2expN (&base_value, fbit, mode);
1080 real_arithmetic (&fixed_value, MULT_EXPR, &real_value, &base_value);
1081 real_to_integer2 ((HOST_WIDE_INT *)&f->data.low, &f->data.high, &fixed_value);
1082 temp = check_real_for_fixed_mode (&real_value, mode);
1083 if (temp == FIXED_UNDERFLOW) /* Minimum. */
1096 lshift_double (f->data.low, f->data.high, i_f_bits,
1097 HOST_BITS_PER_DOUBLE_INT,
1098 &f->data.low, &f->data.high, 1);
1099 f->data = double_int_ext (f->data, 1 + i_f_bits, 0);
1105 else if (temp == FIXED_GT_MAX_EPS || temp == FIXED_MAX_EPS) /* Maximum. */
1111 f->data = double_int_ext (f->data, i_f_bits, 1);
1116 f->data = double_int_ext (f->data, (!unsigned_p) + i_f_bits, unsigned_p);
1120 /* Convert to a new real mode from a fixed-point. */
1123 real_convert_from_fixed (REAL_VALUE_TYPE *r, enum machine_mode mode,
1124 const FIXED_VALUE_TYPE *f)
1126 REAL_VALUE_TYPE base_value, fixed_value, real_value;
1128 real_2expN (&base_value, GET_MODE_FBIT (f->mode), f->mode);
1129 real_from_integer (&fixed_value, VOIDmode, f->data.low, f->data.high,
1130 UNSIGNED_FIXED_POINT_MODE_P (f->mode));
1131 real_arithmetic (&real_value, RDIV_EXPR, &fixed_value, &base_value);
1132 real_convert (r, mode, &real_value);
1135 /* Determine whether a fixed-point value F is negative. */
1138 fixed_isneg (const FIXED_VALUE_TYPE *f)
1140 if (SIGNED_FIXED_POINT_MODE_P (f->mode))
1142 int i_f_bits = GET_MODE_IBIT (f->mode) + GET_MODE_FBIT (f->mode);
1143 int sign_bit = get_fixed_sign_bit (f->data, i_f_bits);