1 /* Fixed-point arithmetic support.
2 Copyright (C) 2006, 2007 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"
26 #include "fixed-value.h"
28 /* Compare two fixed objects for bitwise identity. */
31 fixed_identical (const FIXED_VALUE_TYPE *a, const FIXED_VALUE_TYPE *b)
33 return (a->mode == b->mode
34 && a->data.high == b->data.high
35 && a->data.low == b->data.low);
38 /* Calculate a hash value. */
41 fixed_hash (const FIXED_VALUE_TYPE *f)
43 return (unsigned int) (f->data.low ^ f->data.high);
46 /* Define the enum code for the range of the fixed-point value. */
47 enum fixed_value_range_code {
48 FIXED_OK, /* The value is within the range. */
49 FIXED_UNDERFLOW, /* The value is less than the minimum. */
50 FIXED_GT_MAX_EPS, /* The value is greater than the maximum, but not equal
51 to the maximum plus the epsilon. */
52 FIXED_MAX_EPS /* The value equals the maximum plus the epsilon. */
55 /* Check REAL_VALUE against the range of the fixed-point mode.
56 Return FIXED_OK, if it is within the range.
57 FIXED_UNDERFLOW, if it is less than the minimum.
58 FIXED_GT_MAX_EPS, if it is greater than the maximum, but not equal to
59 the maximum plus the epsilon.
60 FIXED_MAX_EPS, if it is equal to the maximum plus the epsilon. */
62 static enum fixed_value_range_code
63 check_real_for_fixed_mode (REAL_VALUE_TYPE *real_value, enum machine_mode mode)
65 REAL_VALUE_TYPE max_value, min_value, epsilon_value;
67 real_2expN (&max_value, GET_MODE_IBIT (mode), mode);
68 real_2expN (&epsilon_value, -GET_MODE_FBIT (mode), mode);
70 if (SIGNED_FIXED_POINT_MODE_P (mode))
71 min_value = REAL_VALUE_NEGATE (max_value);
73 real_from_string (&min_value, "0.0");
75 if (real_compare (LT_EXPR, real_value, &min_value))
76 return FIXED_UNDERFLOW;
77 if (real_compare (EQ_EXPR, real_value, &max_value))
79 real_arithmetic (&max_value, MINUS_EXPR, &max_value, &epsilon_value);
80 if (real_compare (GT_EXPR, real_value, &max_value))
81 return FIXED_GT_MAX_EPS;
85 /* Initialize from a decimal or hexadecimal string. */
88 fixed_from_string (FIXED_VALUE_TYPE *f, const char *str, enum machine_mode mode)
90 REAL_VALUE_TYPE real_value, fixed_value, base_value;
92 enum fixed_value_range_code temp;
95 fbit = GET_MODE_FBIT (mode);
97 real_from_string (&real_value, str);
98 temp = check_real_for_fixed_mode (&real_value, f->mode);
99 /* We don't want to warn the case when the _Fract value is 1.0. */
100 if (temp == FIXED_UNDERFLOW
101 || temp == FIXED_GT_MAX_EPS
102 || (temp == FIXED_MAX_EPS && ALL_ACCUM_MODE_P (f->mode)))
103 warning (OPT_Woverflow,
104 "large fixed-point constant implicitly truncated to fixed-point type");
105 real_2expN (&base_value, fbit, mode);
106 real_arithmetic (&fixed_value, MULT_EXPR, &real_value, &base_value);
107 real_to_integer2 ((HOST_WIDE_INT *)&f->data.low, &f->data.high,
110 if (temp == FIXED_MAX_EPS && ALL_FRACT_MODE_P (f->mode))
112 /* From the spec, we need to evaluate 1 to the maximal value. */
115 f->data = double_int_ext (f->data,
116 GET_MODE_FBIT (f->mode)
117 + GET_MODE_IBIT (f->mode), 1);
120 f->data = double_int_ext (f->data,
121 SIGNED_FIXED_POINT_MODE_P (f->mode)
122 + GET_MODE_FBIT (f->mode)
123 + GET_MODE_IBIT (f->mode),
124 UNSIGNED_FIXED_POINT_MODE_P (f->mode));
127 /* Render F as a decimal floating point constant. */
130 fixed_to_decimal (char *str, const FIXED_VALUE_TYPE *f_orig,
133 REAL_VALUE_TYPE real_value, base_value, fixed_value;
135 real_2expN (&base_value, GET_MODE_FBIT (f_orig->mode), f_orig->mode);
136 real_from_integer (&real_value, VOIDmode, f_orig->data.low, f_orig->data.high,
137 UNSIGNED_FIXED_POINT_MODE_P (f_orig->mode));
138 real_arithmetic (&fixed_value, RDIV_EXPR, &real_value, &base_value);
139 real_to_decimal (str, &fixed_value, buf_size, 0, 1);
142 /* If SAT_P, saturate A to the maximum or the minimum, and save to *F based on
143 the machine mode MODE.
144 Do not modify *F otherwise.
145 This function assumes the width of double_int is greater than the width
146 of the fixed-point value (the sum of a possible sign bit, possible ibits,
148 Return true, if !SAT_P and overflow. */
151 fixed_saturate1 (enum machine_mode mode, double_int a, double_int *f,
154 bool overflow_p = false;
155 bool unsigned_p = UNSIGNED_FIXED_POINT_MODE_P (mode);
156 int i_f_bits = GET_MODE_IBIT (mode) + GET_MODE_FBIT (mode);
158 if (unsigned_p) /* Unsigned type. */
163 max = double_int_ext (max, i_f_bits, 1);
164 if (double_int_cmp (a, max, 1) == 1)
172 else /* Signed type. */
177 max = double_int_ext (max, i_f_bits, 1);
180 lshift_double (min.low, min.high, i_f_bits,
181 2 * HOST_BITS_PER_WIDE_INT,
182 &min.low, &min.high, 1);
183 min = double_int_ext (min, 1 + i_f_bits, 0);
184 if (double_int_cmp (a, max, 0) == 1)
191 else if (double_int_cmp (a, min, 0) == -1)
202 /* If SAT_P, saturate {A_HIGH, A_LOW} to the maximum or the minimum, and
203 save to *F based on the machine mode MODE.
204 Do not modify *F otherwise.
205 This function assumes the width of two double_int is greater than the width
206 of the fixed-point value (the sum of a possible sign bit, possible ibits,
208 Return true, if !SAT_P and overflow. */
211 fixed_saturate2 (enum machine_mode mode, double_int a_high, double_int a_low,
212 double_int *f, bool sat_p)
214 bool overflow_p = false;
215 bool unsigned_p = UNSIGNED_FIXED_POINT_MODE_P (mode);
216 int i_f_bits = GET_MODE_IBIT (mode) + GET_MODE_FBIT (mode);
218 if (unsigned_p) /* Unsigned type. */
220 double_int max_r, max_s;
225 max_s = double_int_ext (max_s, i_f_bits, 1);
226 if (double_int_cmp (a_high, max_r, 1) == 1
227 || (double_int_equal_p (a_high, max_r) &&
228 double_int_cmp (a_low, max_s, 1) == 1))
236 else /* Signed type. */
238 double_int max_r, max_s, min_r, min_s;
243 max_s = double_int_ext (max_s, i_f_bits, 1);
248 lshift_double (min_s.low, min_s.high, i_f_bits,
249 2 * HOST_BITS_PER_WIDE_INT,
250 &min_s.low, &min_s.high, 1);
251 min_s = double_int_ext (min_s, 1 + i_f_bits, 0);
252 if (double_int_cmp (a_high, max_r, 0) == 1
253 || (double_int_equal_p (a_high, max_r) &&
254 double_int_cmp (a_low, max_s, 1) == 1))
261 else if (double_int_cmp (a_high, min_r, 0) == -1
262 || (double_int_equal_p (a_high, min_r) &&
263 double_int_cmp (a_low, min_s, 1) == -1))
274 /* Return the sign bit based on I_F_BITS. */
277 get_fixed_sign_bit (double_int a, int i_f_bits)
279 if (i_f_bits < HOST_BITS_PER_WIDE_INT)
280 return (a.low >> i_f_bits) & 1;
282 return (a.high >> (i_f_bits - HOST_BITS_PER_WIDE_INT)) & 1;
285 /* Calculate F = A + (SUBTRACT_P ? -B : B).
286 If SAT_P, saturate the result to the max or the min.
287 Return true, if !SAT_P and overflow. */
290 do_fixed_add (FIXED_VALUE_TYPE *f, const FIXED_VALUE_TYPE *a,
291 const FIXED_VALUE_TYPE *b, bool subtract_p, bool sat_p)
293 bool overflow_p = false;
298 /* This was a conditional expression but it triggered a bug in the
299 Solaris 8 compiler. */
301 temp = double_int_neg (b->data);
305 unsigned_p = UNSIGNED_FIXED_POINT_MODE_P (a->mode);
306 i_f_bits = GET_MODE_IBIT (a->mode) + GET_MODE_FBIT (a->mode);
308 f->data = double_int_add (a->data, temp);
309 if (unsigned_p) /* Unsigned type. */
311 if (subtract_p) /* Unsigned subtraction. */
313 if (double_int_cmp (a->data, b->data, 1) == -1)
324 else /* Unsigned addition. */
326 f->data = double_int_ext (f->data, i_f_bits, 1);
327 if (double_int_cmp (f->data, a->data, 1) == -1
328 || double_int_cmp (f->data, b->data, 1) == -1)
340 else /* Signed type. */
343 && (get_fixed_sign_bit (a->data, i_f_bits)
344 == get_fixed_sign_bit (b->data, i_f_bits))
345 && (get_fixed_sign_bit (a->data, i_f_bits)
346 != get_fixed_sign_bit (f->data, i_f_bits)))
348 && (get_fixed_sign_bit (a->data, i_f_bits)
349 != get_fixed_sign_bit (b->data, i_f_bits))
350 && (get_fixed_sign_bit (a->data, i_f_bits)
351 != get_fixed_sign_bit (f->data, i_f_bits))))
357 lshift_double (f->data.low, f->data.high, i_f_bits,
358 2 * HOST_BITS_PER_WIDE_INT,
359 &f->data.low, &f->data.high, 1);
360 if (get_fixed_sign_bit (a->data, i_f_bits) == 0)
365 f->data = double_int_add (f->data, double_int_neg (one));
372 f->data = double_int_ext (f->data, (!unsigned_p) + i_f_bits, unsigned_p);
376 /* Calculate F = A * B.
377 If SAT_P, saturate the result to the max or the min.
378 Return true, if !SAT_P and overflow. */
381 do_fixed_multiply (FIXED_VALUE_TYPE *f, const FIXED_VALUE_TYPE *a,
382 const FIXED_VALUE_TYPE *b, bool sat_p)
384 bool overflow_p = false;
385 bool unsigned_p = UNSIGNED_FIXED_POINT_MODE_P (a->mode);
386 int i_f_bits = GET_MODE_IBIT (a->mode) + GET_MODE_FBIT (a->mode);
388 if (GET_MODE_PRECISION (f->mode) <= HOST_BITS_PER_WIDE_INT)
390 f->data = double_int_mul (a->data, b->data);
391 lshift_double (f->data.low, f->data.high,
392 (-GET_MODE_FBIT (f->mode)),
393 2 * HOST_BITS_PER_WIDE_INT,
394 &f->data.low, &f->data.high, !unsigned_p);
395 overflow_p = fixed_saturate1 (f->mode, f->data, &f->data, sat_p);
399 /* The result of multiplication expands to two double_int. */
400 double_int a_high, a_low, b_high, b_low;
401 double_int high_high, high_low, low_high, low_low;
402 double_int r, s, temp1, temp2;
405 /* Decompose a and b to four double_int. */
406 a_high.low = a->data.high;
408 a_low.low = a->data.low;
410 b_high.low = b->data.high;
412 b_low.low = b->data.low;
415 /* Perform four multiplications. */
416 low_low = double_int_mul (a_low, b_low);
417 low_high = double_int_mul (a_low, b_high);
418 high_low = double_int_mul (a_high, b_low);
419 high_high = double_int_mul (a_high, b_high);
421 /* Accumulate four results to {r, s}. */
422 temp1.high = high_low.low;
424 s = double_int_add (low_low, temp1);
425 if (double_int_cmp (s, low_low, 1) == -1
426 || double_int_cmp (s, temp1, 1) == -1)
427 carry ++; /* Carry */
430 temp2.high = low_high.low;
432 s = double_int_add (temp1, temp2);
433 if (double_int_cmp (s, temp1, 1) == -1
434 || double_int_cmp (s, temp2, 1) == -1)
435 carry ++; /* Carry */
437 temp1.low = high_low.high;
439 r = double_int_add (high_high, temp1);
440 temp1.low = low_high.high;
442 r = double_int_add (r, temp1);
445 r = double_int_add (r, temp1);
447 /* We need to add neg(b) to r, if a < 0. */
448 if (!unsigned_p && a->data.high < 0)
449 r = double_int_add (r, double_int_neg (b->data));
450 /* We need to add neg(a) to r, if b < 0. */
451 if (!unsigned_p && b->data.high < 0)
452 r = double_int_add (r, double_int_neg (a->data));
454 /* Shift right the result by FBIT. */
455 if (GET_MODE_FBIT (f->mode) == 2 * HOST_BITS_PER_WIDE_INT)
470 f->data.high = s.high;
474 lshift_double (s.low, s.high,
475 (-GET_MODE_FBIT (f->mode)),
476 2 * HOST_BITS_PER_WIDE_INT,
478 lshift_double (r.low, r.high,
479 (2 * HOST_BITS_PER_WIDE_INT
480 - GET_MODE_FBIT (f->mode)),
481 2 * HOST_BITS_PER_WIDE_INT,
482 &f->data.low, &f->data.high, 0);
483 f->data.low = f->data.low | s.low;
484 f->data.high = f->data.high | s.high;
486 s.high = f->data.high;
487 lshift_double (r.low, r.high,
488 (-GET_MODE_FBIT (f->mode)),
489 2 * HOST_BITS_PER_WIDE_INT,
490 &r.low, &r.high, !unsigned_p);
493 overflow_p = fixed_saturate2 (f->mode, r, s, &f->data, sat_p);
496 f->data = double_int_ext (f->data, (!unsigned_p) + i_f_bits, unsigned_p);
500 /* Calculate F = A / B.
501 If SAT_P, saturate the result to the max or the min.
502 Return true, if !SAT_P and overflow. */
505 do_fixed_divide (FIXED_VALUE_TYPE *f, const FIXED_VALUE_TYPE *a,
506 const FIXED_VALUE_TYPE *b, bool sat_p)
508 bool overflow_p = false;
509 bool unsigned_p = UNSIGNED_FIXED_POINT_MODE_P (a->mode);
510 int i_f_bits = GET_MODE_IBIT (a->mode) + GET_MODE_FBIT (a->mode);
512 if (GET_MODE_PRECISION (f->mode) <= HOST_BITS_PER_WIDE_INT)
514 lshift_double (a->data.low, a->data.high,
515 GET_MODE_FBIT (f->mode),
516 2 * HOST_BITS_PER_WIDE_INT,
517 &f->data.low, &f->data.high, !unsigned_p);
518 f->data = double_int_div (f->data, b->data, unsigned_p, TRUNC_DIV_EXPR);
519 overflow_p = fixed_saturate1 (f->mode, f->data, &f->data, sat_p);
523 double_int pos_a, pos_b, r, s;
524 double_int quo_r, quo_s, mod, temp;
528 /* If a < 0, negate a. */
529 if (!unsigned_p && a->data.high < 0)
531 pos_a = double_int_neg (a->data);
537 /* If b < 0, negate b. */
538 if (!unsigned_p && b->data.high < 0)
540 pos_b = double_int_neg (b->data);
546 /* Left shift pos_a to {r, s} by FBIT. */
547 if (GET_MODE_FBIT (f->mode) == 2 * HOST_BITS_PER_WIDE_INT)
555 lshift_double (pos_a.low, pos_a.high,
556 GET_MODE_FBIT (f->mode),
557 2 * HOST_BITS_PER_WIDE_INT,
559 lshift_double (pos_a.low, pos_a.high,
560 - (2 * HOST_BITS_PER_WIDE_INT
561 - GET_MODE_FBIT (f->mode)),
562 2 * HOST_BITS_PER_WIDE_INT,
566 /* Divide r by pos_b to quo_r. The remainder is in mod. */
567 div_and_round_double (TRUNC_DIV_EXPR, 1, r.low, r.high, pos_b.low,
568 pos_b.high, &quo_r.low, &quo_r.high, &mod.low,
574 for (i = 0; i < 2 * HOST_BITS_PER_WIDE_INT; i++)
576 /* Record the leftmost bit of mod. */
577 int leftmost_mod = (mod.high < 0);
579 /* Shift left mod by 1 bit. */
580 lshift_double (mod.low, mod.high, 1, 2 * HOST_BITS_PER_WIDE_INT,
581 &mod.low, &mod.high, 0);
583 /* Test the leftmost bit of s to add to mod. */
587 /* Shift left quo_s by 1 bit. */
588 lshift_double (quo_s.low, quo_s.high, 1, 2 * HOST_BITS_PER_WIDE_INT,
589 &quo_s.low, &quo_s.high, 0);
591 /* Try to calculate (mod - pos_b). */
592 temp = double_int_add (mod, double_int_neg (pos_b));
594 if (leftmost_mod == 1 || double_int_cmp (mod, pos_b, 1) != -1)
600 /* Shift left s by 1 bit. */
601 lshift_double (s.low, s.high, 1, 2 * HOST_BITS_PER_WIDE_INT,
608 quo_s = double_int_neg (quo_s);
609 if (quo_s.high == 0 && quo_s.low == 0)
610 quo_r = double_int_neg (quo_r);
613 quo_r.low = ~quo_r.low;
614 quo_r.high = ~quo_r.high;
619 overflow_p = fixed_saturate2 (f->mode, quo_r, quo_s, &f->data, sat_p);
622 f->data = double_int_ext (f->data, (!unsigned_p) + i_f_bits, unsigned_p);
626 /* Calculate F = A << B if LEFT_P. Otherwise, F = A >> B.
627 If SAT_P, saturate the result to the max or the min.
628 Return true, if !SAT_P and overflow. */
631 do_fixed_shift (FIXED_VALUE_TYPE *f, const FIXED_VALUE_TYPE *a,
632 const FIXED_VALUE_TYPE *b, bool left_p, bool sat_p)
634 bool overflow_p = false;
635 bool unsigned_p = UNSIGNED_FIXED_POINT_MODE_P (a->mode);
636 int i_f_bits = GET_MODE_IBIT (a->mode) + GET_MODE_FBIT (a->mode);
639 if (b->data.low == 0)
645 if (GET_MODE_PRECISION (f->mode) <= HOST_BITS_PER_WIDE_INT || (!left_p))
647 lshift_double (a->data.low, a->data.high,
648 left_p ? b->data.low : (-b->data.low),
649 2 * HOST_BITS_PER_WIDE_INT,
650 &f->data.low, &f->data.high, !unsigned_p);
651 if (left_p) /* Only left shift saturates. */
652 overflow_p = fixed_saturate1 (f->mode, f->data, &f->data, sat_p);
654 else /* We need two double_int to store the left-shift result. */
656 double_int temp_high, temp_low;
657 if (b->data.low == 2 * HOST_BITS_PER_WIDE_INT)
665 lshift_double (a->data.low, a->data.high,
667 2 * HOST_BITS_PER_WIDE_INT,
668 &temp_low.low, &temp_low.high, !unsigned_p);
669 /* Logical shift right to temp_high. */
670 lshift_double (a->data.low, a->data.high,
671 b->data.low - 2 * HOST_BITS_PER_WIDE_INT,
672 2 * HOST_BITS_PER_WIDE_INT,
673 &temp_high.low, &temp_high.high, 0);
675 if (!unsigned_p && a->data.high < 0) /* Signed-extend temp_high. */
676 temp_high = double_int_ext (temp_high, b->data.low, unsigned_p);
678 overflow_p = fixed_saturate2 (f->mode, temp_high, temp_low, &f->data,
681 f->data = double_int_ext (f->data, (!unsigned_p) + i_f_bits, unsigned_p);
686 If SAT_P, saturate the result to the max or the min.
687 Return true, if !SAT_P and overflow. */
690 do_fixed_neg (FIXED_VALUE_TYPE *f, const FIXED_VALUE_TYPE *a, bool sat_p)
692 bool overflow_p = false;
693 bool unsigned_p = UNSIGNED_FIXED_POINT_MODE_P (a->mode);
694 int i_f_bits = GET_MODE_IBIT (a->mode) + GET_MODE_FBIT (a->mode);
696 f->data = double_int_neg (a->data);
697 f->data = double_int_ext (f->data, (!unsigned_p) + i_f_bits, unsigned_p);
699 if (unsigned_p) /* Unsigned type. */
701 if (f->data.low != 0 || f->data.high != 0)
712 else /* Signed type. */
714 if (!(f->data.high == 0 && f->data.low == 0)
715 && f->data.high == a->data.high && f->data.low == a->data.low )
719 /* Saturate to the maximum by subtracting f->data by one. */
722 f->data = double_int_ext (f->data, i_f_bits, 1);
731 /* Perform the binary or unary operation described by CODE.
732 Note that OP0 and OP1 must have the same mode for binary operators.
733 For a unary operation, leave OP1 NULL.
734 Return true, if !SAT_P and overflow. */
737 fixed_arithmetic (FIXED_VALUE_TYPE *f, int icode, const FIXED_VALUE_TYPE *op0,
738 const FIXED_VALUE_TYPE *op1, bool sat_p)
743 return do_fixed_neg (f, op0, sat_p);
747 gcc_assert (op0->mode == op1->mode);
748 return do_fixed_add (f, op0, op1, false, sat_p);
752 gcc_assert (op0->mode == op1->mode);
753 return do_fixed_add (f, op0, op1, true, sat_p);
757 gcc_assert (op0->mode == op1->mode);
758 return do_fixed_multiply (f, op0, op1, sat_p);
762 gcc_assert (op0->mode == op1->mode);
763 return do_fixed_divide (f, op0, op1, sat_p);
767 return do_fixed_shift (f, op0, op1, true, sat_p);
771 return do_fixed_shift (f, op0, op1, false, sat_p);
780 /* Compare fixed-point values by tree_code.
781 Note that OP0 and OP1 must have the same mode. */
784 fixed_compare (int icode, const FIXED_VALUE_TYPE *op0,
785 const FIXED_VALUE_TYPE *op1)
787 enum tree_code code = icode;
788 gcc_assert (op0->mode == op1->mode);
793 return !double_int_equal_p (op0->data, op1->data);
796 return double_int_equal_p (op0->data, op1->data);
799 return double_int_cmp (op0->data, op1->data,
800 UNSIGNED_FIXED_POINT_MODE_P (op0->mode)) == -1;
803 return double_int_cmp (op0->data, op1->data,
804 UNSIGNED_FIXED_POINT_MODE_P (op0->mode)) != 1;
807 return double_int_cmp (op0->data, op1->data,
808 UNSIGNED_FIXED_POINT_MODE_P (op0->mode)) == 1;
811 return double_int_cmp (op0->data, op1->data,
812 UNSIGNED_FIXED_POINT_MODE_P (op0->mode)) != -1;
819 /* Extend or truncate to a new mode.
820 If SAT_P, saturate the result to the max or the min.
821 Return true, if !SAT_P and overflow. */
824 fixed_convert (FIXED_VALUE_TYPE *f, enum machine_mode mode,
825 const FIXED_VALUE_TYPE *a, bool sat_p)
827 bool overflow_p = false;
834 if (GET_MODE_FBIT (mode) > GET_MODE_FBIT (a->mode))
836 /* Left shift a to temp_high, temp_low based on a->mode. */
837 double_int temp_high, temp_low;
838 int amount = GET_MODE_FBIT (mode) - GET_MODE_FBIT (a->mode);
839 lshift_double (a->data.low, a->data.high,
841 2 * HOST_BITS_PER_WIDE_INT,
842 &temp_low.low, &temp_low.high,
843 SIGNED_FIXED_POINT_MODE_P (a->mode));
844 /* Logical shift right to temp_high. */
845 lshift_double (a->data.low, a->data.high,
846 amount - 2 * HOST_BITS_PER_WIDE_INT,
847 2 * HOST_BITS_PER_WIDE_INT,
848 &temp_high.low, &temp_high.high, 0);
849 if (SIGNED_FIXED_POINT_MODE_P (a->mode)
850 && a->data.high < 0) /* Signed-extend temp_high. */
851 temp_high = double_int_ext (temp_high, amount, 0);
854 if (SIGNED_FIXED_POINT_MODE_P (a->mode) ==
855 SIGNED_FIXED_POINT_MODE_P (f->mode))
856 overflow_p = fixed_saturate2 (f->mode, temp_high, temp_low, &f->data,
860 /* Take care of the cases when converting between signed and
862 if (SIGNED_FIXED_POINT_MODE_P (a->mode))
864 /* Signed -> Unsigned. */
865 if (a->data.high < 0)
869 f->data.low = 0; /* Set to zero. */
870 f->data.high = 0; /* Set to zero. */
876 overflow_p = fixed_saturate2 (f->mode, temp_high, temp_low,
881 /* Unsigned -> Signed. */
882 if (temp_high.high < 0)
886 /* Set to maximum. */
887 f->data.low = -1; /* Set to all ones. */
888 f->data.high = -1; /* Set to all ones. */
889 f->data = double_int_ext (f->data,
890 GET_MODE_FBIT (f->mode)
891 + GET_MODE_IBIT (f->mode),
892 1); /* Clear the sign. */
898 overflow_p = fixed_saturate2 (f->mode, temp_high, temp_low,
905 /* Right shift a to temp based on a->mode. */
907 lshift_double (a->data.low, a->data.high,
908 GET_MODE_FBIT (mode) - GET_MODE_FBIT (a->mode),
909 2 * HOST_BITS_PER_WIDE_INT,
910 &temp.low, &temp.high,
911 SIGNED_FIXED_POINT_MODE_P (a->mode));
914 if (SIGNED_FIXED_POINT_MODE_P (a->mode) ==
915 SIGNED_FIXED_POINT_MODE_P (f->mode))
916 overflow_p = fixed_saturate1 (f->mode, f->data, &f->data, sat_p);
919 /* Take care of the cases when converting between signed and
921 if (SIGNED_FIXED_POINT_MODE_P (a->mode))
923 /* Signed -> Unsigned. */
924 if (a->data.high < 0)
928 f->data.low = 0; /* Set to zero. */
929 f->data.high = 0; /* Set to zero. */
935 overflow_p = fixed_saturate1 (f->mode, f->data, &f->data,
940 /* Unsigned -> Signed. */
945 /* Set to maximum. */
946 f->data.low = -1; /* Set to all ones. */
947 f->data.high = -1; /* Set to all ones. */
948 f->data = double_int_ext (f->data,
949 GET_MODE_FBIT (f->mode)
950 + GET_MODE_IBIT (f->mode),
951 1); /* Clear the sign. */
957 overflow_p = fixed_saturate1 (f->mode, f->data, &f->data,
963 f->data = double_int_ext (f->data,
964 SIGNED_FIXED_POINT_MODE_P (f->mode)
965 + GET_MODE_FBIT (f->mode)
966 + GET_MODE_IBIT (f->mode),
967 UNSIGNED_FIXED_POINT_MODE_P (f->mode));
971 /* Convert to a new fixed-point mode from an integer.
972 If UNSIGNED_P, this integer is unsigned.
973 If SAT_P, saturate the result to the max or the min.
974 Return true, if !SAT_P and overflow. */
977 fixed_convert_from_int (FIXED_VALUE_TYPE *f, enum machine_mode mode,
978 double_int a, bool unsigned_p, bool sat_p)
980 bool overflow_p = false;
981 /* Left shift a to temp_high, temp_low. */
982 double_int temp_high, temp_low;
983 int amount = GET_MODE_FBIT (mode);
984 if (amount == 2 * HOST_BITS_PER_WIDE_INT)
992 lshift_double (a.low, a.high,
994 2 * HOST_BITS_PER_WIDE_INT,
995 &temp_low.low, &temp_low.high, 0);
997 /* Logical shift right to temp_high. */
998 lshift_double (a.low, a.high,
999 amount - 2 * HOST_BITS_PER_WIDE_INT,
1000 2 * HOST_BITS_PER_WIDE_INT,
1001 &temp_high.low, &temp_high.high, 0);
1003 if (!unsigned_p && a.high < 0) /* Signed-extend temp_high. */
1004 temp_high = double_int_ext (temp_high, amount, 0);
1009 if (unsigned_p == UNSIGNED_FIXED_POINT_MODE_P (f->mode))
1010 overflow_p = fixed_saturate2 (f->mode, temp_high, temp_low, &f->data,
1014 /* Take care of the cases when converting between signed and unsigned. */
1017 /* Signed -> Unsigned. */
1022 f->data.low = 0; /* Set to zero. */
1023 f->data.high = 0; /* Set to zero. */
1029 overflow_p = fixed_saturate2 (f->mode, temp_high, temp_low,
1034 /* Unsigned -> Signed. */
1035 if (temp_high.high < 0)
1039 /* Set to maximum. */
1040 f->data.low = -1; /* Set to all ones. */
1041 f->data.high = -1; /* Set to all ones. */
1042 f->data = double_int_ext (f->data,
1043 GET_MODE_FBIT (f->mode)
1044 + GET_MODE_IBIT (f->mode),
1045 1); /* Clear the sign. */
1051 overflow_p = fixed_saturate2 (f->mode, temp_high, temp_low,
1055 f->data = double_int_ext (f->data,
1056 SIGNED_FIXED_POINT_MODE_P (f->mode)
1057 + GET_MODE_FBIT (f->mode)
1058 + GET_MODE_IBIT (f->mode),
1059 UNSIGNED_FIXED_POINT_MODE_P (f->mode));
1063 /* Convert to a new fixed-point mode from a real.
1064 If SAT_P, saturate the result to the max or the min.
1065 Return true, if !SAT_P and overflow. */
1068 fixed_convert_from_real (FIXED_VALUE_TYPE *f, enum machine_mode mode,
1069 const REAL_VALUE_TYPE *a, bool sat_p)
1071 bool overflow_p = false;
1072 REAL_VALUE_TYPE real_value, fixed_value, base_value;
1073 bool unsigned_p = UNSIGNED_FIXED_POINT_MODE_P (mode);
1074 int i_f_bits = GET_MODE_IBIT (mode) + GET_MODE_FBIT (mode);
1075 unsigned int fbit = GET_MODE_FBIT (mode);
1076 enum fixed_value_range_code temp;
1080 real_2expN (&base_value, fbit, mode);
1081 real_arithmetic (&fixed_value, MULT_EXPR, &real_value, &base_value);
1082 real_to_integer2 ((HOST_WIDE_INT *)&f->data.low, &f->data.high, &fixed_value);
1083 temp = check_real_for_fixed_mode (&real_value, mode);
1084 if (temp == FIXED_UNDERFLOW) /* Minimum. */
1097 lshift_double (f->data.low, f->data.high, i_f_bits,
1098 2 * HOST_BITS_PER_WIDE_INT,
1099 &f->data.low, &f->data.high, 1);
1100 f->data = double_int_ext (f->data, 1 + i_f_bits, 0);
1106 else if (temp == FIXED_GT_MAX_EPS || temp == FIXED_MAX_EPS) /* Maximum. */
1112 f->data = double_int_ext (f->data, i_f_bits, 1);
1117 f->data = double_int_ext (f->data, (!unsigned_p) + i_f_bits, unsigned_p);
1121 /* Convert to a new real mode from a fixed-point. */
1124 real_convert_from_fixed (REAL_VALUE_TYPE *r, enum machine_mode mode,
1125 const FIXED_VALUE_TYPE *f)
1127 REAL_VALUE_TYPE base_value, fixed_value, real_value;
1129 real_2expN (&base_value, GET_MODE_FBIT (f->mode), f->mode);
1130 real_from_integer (&fixed_value, VOIDmode, f->data.low, f->data.high,
1131 UNSIGNED_FIXED_POINT_MODE_P (f->mode));
1132 real_arithmetic (&real_value, RDIV_EXPR, &fixed_value, &base_value);
1133 real_convert (r, mode, &real_value);
1136 /* Determine whether a fixed-point value F is negative. */
1139 fixed_isneg (const FIXED_VALUE_TYPE *f)
1141 if (SIGNED_FIXED_POINT_MODE_P (f->mode))
1143 int i_f_bits = GET_MODE_IBIT (f->mode) + GET_MODE_FBIT (f->mode);
1144 int sign_bit = get_fixed_sign_bit (f->data, i_f_bits);