| /* Fixed-point arithmetic support. |
| Copyright (C) 2006-2022 Free Software Foundation, Inc. |
| |
| This file is part of GCC. |
| |
| GCC is free software; you can redistribute it and/or modify it under |
| the terms of the GNU General Public License as published by the Free |
| Software Foundation; either version 3, or (at your option) any later |
| version. |
| |
| GCC is distributed in the hope that it will be useful, but WITHOUT ANY |
| WARRANTY; without even the implied warranty of MERCHANTABILITY or |
| FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License |
| for more details. |
| |
| You should have received a copy of the GNU General Public License |
| along with GCC; see the file COPYING3. If not see |
| <http://www.gnu.org/licenses/>. */ |
| |
| #include "config.h" |
| #include "system.h" |
| #include "coretypes.h" |
| #include "tm.h" |
| #include "tree.h" |
| #include "diagnostic-core.h" |
| |
| /* Compare two fixed objects for bitwise identity. */ |
| |
| bool |
| fixed_identical (const FIXED_VALUE_TYPE *a, const FIXED_VALUE_TYPE *b) |
| { |
| return (a->mode == b->mode |
| && a->data.high == b->data.high |
| && a->data.low == b->data.low); |
| } |
| |
| /* Calculate a hash value. */ |
| |
| unsigned int |
| fixed_hash (const FIXED_VALUE_TYPE *f) |
| { |
| return (unsigned int) (f->data.low ^ f->data.high); |
| } |
| |
| /* Define the enum code for the range of the fixed-point value. */ |
| enum fixed_value_range_code { |
| FIXED_OK, /* The value is within the range. */ |
| FIXED_UNDERFLOW, /* The value is less than the minimum. */ |
| FIXED_GT_MAX_EPS, /* The value is greater than the maximum, but not equal |
| to the maximum plus the epsilon. */ |
| FIXED_MAX_EPS /* The value equals the maximum plus the epsilon. */ |
| }; |
| |
| /* Check REAL_VALUE against the range of the fixed-point mode. |
| Return FIXED_OK, if it is within the range. |
| FIXED_UNDERFLOW, if it is less than the minimum. |
| FIXED_GT_MAX_EPS, if it is greater than the maximum, but not equal to |
| the maximum plus the epsilon. |
| FIXED_MAX_EPS, if it is equal to the maximum plus the epsilon. */ |
| |
| static enum fixed_value_range_code |
| check_real_for_fixed_mode (REAL_VALUE_TYPE *real_value, machine_mode mode) |
| { |
| REAL_VALUE_TYPE max_value, min_value, epsilon_value; |
| |
| real_2expN (&max_value, GET_MODE_IBIT (mode), VOIDmode); |
| real_2expN (&epsilon_value, -GET_MODE_FBIT (mode), VOIDmode); |
| |
| if (SIGNED_FIXED_POINT_MODE_P (mode)) |
| min_value = real_value_negate (&max_value); |
| else |
| real_from_string (&min_value, "0.0"); |
| |
| if (real_compare (LT_EXPR, real_value, &min_value)) |
| return FIXED_UNDERFLOW; |
| if (real_compare (EQ_EXPR, real_value, &max_value)) |
| return FIXED_MAX_EPS; |
| real_arithmetic (&max_value, MINUS_EXPR, &max_value, &epsilon_value); |
| if (real_compare (GT_EXPR, real_value, &max_value)) |
| return FIXED_GT_MAX_EPS; |
| return FIXED_OK; |
| } |
| |
| |
| /* Construct a CONST_FIXED from a bit payload and machine mode MODE. |
| The bits in PAYLOAD are sign-extended/zero-extended according to MODE. */ |
| |
| FIXED_VALUE_TYPE |
| fixed_from_double_int (double_int payload, scalar_mode mode) |
| { |
| FIXED_VALUE_TYPE value; |
| |
| gcc_assert (GET_MODE_BITSIZE (mode) <= HOST_BITS_PER_DOUBLE_INT); |
| |
| if (SIGNED_SCALAR_FIXED_POINT_MODE_P (mode)) |
| value.data = payload.sext (1 + GET_MODE_IBIT (mode) + GET_MODE_FBIT (mode)); |
| else if (UNSIGNED_SCALAR_FIXED_POINT_MODE_P (mode)) |
| value.data = payload.zext (GET_MODE_IBIT (mode) + GET_MODE_FBIT (mode)); |
| else |
| gcc_unreachable (); |
| |
| value.mode = mode; |
| |
| return value; |
| } |
| |
| |
| /* Initialize from a decimal or hexadecimal string. */ |
| |
| void |
| fixed_from_string (FIXED_VALUE_TYPE *f, const char *str, scalar_mode mode) |
| { |
| REAL_VALUE_TYPE real_value, fixed_value, base_value; |
| unsigned int fbit; |
| enum fixed_value_range_code temp; |
| bool fail; |
| |
| f->mode = mode; |
| fbit = GET_MODE_FBIT (mode); |
| |
| real_from_string (&real_value, str); |
| temp = check_real_for_fixed_mode (&real_value, f->mode); |
| /* We don't want to warn the case when the _Fract value is 1.0. */ |
| if (temp == FIXED_UNDERFLOW |
| || temp == FIXED_GT_MAX_EPS |
| || (temp == FIXED_MAX_EPS && ALL_ACCUM_MODE_P (f->mode))) |
| warning (OPT_Woverflow, |
| "large fixed-point constant implicitly truncated to fixed-point type"); |
| real_2expN (&base_value, fbit, VOIDmode); |
| real_arithmetic (&fixed_value, MULT_EXPR, &real_value, &base_value); |
| wide_int w = real_to_integer (&fixed_value, &fail, |
| GET_MODE_PRECISION (mode)); |
| f->data.low = w.ulow (); |
| f->data.high = w.elt (1); |
| |
| if (temp == FIXED_MAX_EPS && ALL_FRACT_MODE_P (f->mode)) |
| { |
| /* From the spec, we need to evaluate 1 to the maximal value. */ |
| f->data.low = -1; |
| f->data.high = -1; |
| f->data = f->data.zext (GET_MODE_FBIT (f->mode) |
| + GET_MODE_IBIT (f->mode)); |
| } |
| else |
| f->data = f->data.ext (SIGNED_FIXED_POINT_MODE_P (f->mode) |
| + GET_MODE_FBIT (f->mode) |
| + GET_MODE_IBIT (f->mode), |
| UNSIGNED_FIXED_POINT_MODE_P (f->mode)); |
| } |
| |
| /* Render F as a decimal floating point constant. */ |
| |
| void |
| fixed_to_decimal (char *str, const FIXED_VALUE_TYPE *f_orig, |
| size_t buf_size) |
| { |
| REAL_VALUE_TYPE real_value, base_value, fixed_value; |
| |
| signop sgn = UNSIGNED_FIXED_POINT_MODE_P (f_orig->mode) ? UNSIGNED : SIGNED; |
| real_2expN (&base_value, GET_MODE_FBIT (f_orig->mode), VOIDmode); |
| real_from_integer (&real_value, VOIDmode, |
| wide_int::from (f_orig->data, |
| GET_MODE_PRECISION (f_orig->mode), sgn), |
| sgn); |
| real_arithmetic (&fixed_value, RDIV_EXPR, &real_value, &base_value); |
| real_to_decimal (str, &fixed_value, buf_size, 0, 1); |
| } |
| |
| /* If SAT_P, saturate A to the maximum or the minimum, and save to *F based on |
| the machine mode MODE. |
| Do not modify *F otherwise. |
| This function assumes the width of double_int is greater than the width |
| of the fixed-point value (the sum of a possible sign bit, possible ibits, |
| and fbits). |
| Return true, if !SAT_P and overflow. */ |
| |
| static bool |
| fixed_saturate1 (machine_mode mode, double_int a, double_int *f, |
| bool sat_p) |
| { |
| bool overflow_p = false; |
| bool unsigned_p = UNSIGNED_FIXED_POINT_MODE_P (mode); |
| int i_f_bits = GET_MODE_IBIT (mode) + GET_MODE_FBIT (mode); |
| |
| if (unsigned_p) /* Unsigned type. */ |
| { |
| double_int max; |
| max.low = -1; |
| max.high = -1; |
| max = max.zext (i_f_bits); |
| if (a.ugt (max)) |
| { |
| if (sat_p) |
| *f = max; |
| else |
| overflow_p = true; |
| } |
| } |
| else /* Signed type. */ |
| { |
| double_int max, min; |
| max.high = -1; |
| max.low = -1; |
| max = max.zext (i_f_bits); |
| min.high = 0; |
| min.low = 1; |
| min = min.alshift (i_f_bits, HOST_BITS_PER_DOUBLE_INT); |
| min = min.sext (1 + i_f_bits); |
| if (a.sgt (max)) |
| { |
| if (sat_p) |
| *f = max; |
| else |
| overflow_p = true; |
| } |
| else if (a.slt (min)) |
| { |
| if (sat_p) |
| *f = min; |
| else |
| overflow_p = true; |
| } |
| } |
| return overflow_p; |
| } |
| |
| /* If SAT_P, saturate {A_HIGH, A_LOW} to the maximum or the minimum, and |
| save to *F based on the machine mode MODE. |
| Do not modify *F otherwise. |
| This function assumes the width of two double_int is greater than the width |
| of the fixed-point value (the sum of a possible sign bit, possible ibits, |
| and fbits). |
| Return true, if !SAT_P and overflow. */ |
| |
| static bool |
| fixed_saturate2 (machine_mode mode, double_int a_high, double_int a_low, |
| double_int *f, bool sat_p) |
| { |
| bool overflow_p = false; |
| bool unsigned_p = UNSIGNED_FIXED_POINT_MODE_P (mode); |
| int i_f_bits = GET_MODE_IBIT (mode) + GET_MODE_FBIT (mode); |
| |
| if (unsigned_p) /* Unsigned type. */ |
| { |
| double_int max_r, max_s; |
| max_r.high = 0; |
| max_r.low = 0; |
| max_s.high = -1; |
| max_s.low = -1; |
| max_s = max_s.zext (i_f_bits); |
| if (a_high.ugt (max_r) |
| || (a_high == max_r && |
| a_low.ugt (max_s))) |
| { |
| if (sat_p) |
| *f = max_s; |
| else |
| overflow_p = true; |
| } |
| } |
| else /* Signed type. */ |
| { |
| double_int max_r, max_s, min_r, min_s; |
| max_r.high = 0; |
| max_r.low = 0; |
| max_s.high = -1; |
| max_s.low = -1; |
| max_s = max_s.zext (i_f_bits); |
| min_r.high = -1; |
| min_r.low = -1; |
| min_s.high = 0; |
| min_s.low = 1; |
| min_s = min_s.alshift (i_f_bits, HOST_BITS_PER_DOUBLE_INT); |
| min_s = min_s.sext (1 + i_f_bits); |
| if (a_high.sgt (max_r) |
| || (a_high == max_r && |
| a_low.ugt (max_s))) |
| { |
| if (sat_p) |
| *f = max_s; |
| else |
| overflow_p = true; |
| } |
| else if (a_high.slt (min_r) |
| || (a_high == min_r && |
| a_low.ult (min_s))) |
| { |
| if (sat_p) |
| *f = min_s; |
| else |
| overflow_p = true; |
| } |
| } |
| return overflow_p; |
| } |
| |
| /* Return the sign bit based on I_F_BITS. */ |
| |
| static inline int |
| get_fixed_sign_bit (double_int a, int i_f_bits) |
| { |
| if (i_f_bits < HOST_BITS_PER_WIDE_INT) |
| return (a.low >> i_f_bits) & 1; |
| else |
| return (a.high >> (i_f_bits - HOST_BITS_PER_WIDE_INT)) & 1; |
| } |
| |
| /* Calculate F = A + (SUBTRACT_P ? -B : B). |
| If SAT_P, saturate the result to the max or the min. |
| Return true, if !SAT_P and overflow. */ |
| |
| static bool |
| do_fixed_add (FIXED_VALUE_TYPE *f, const FIXED_VALUE_TYPE *a, |
| const FIXED_VALUE_TYPE *b, bool subtract_p, bool sat_p) |
| { |
| bool overflow_p = false; |
| bool unsigned_p; |
| double_int temp; |
| int i_f_bits; |
| |
| /* This was a conditional expression but it triggered a bug in |
| Sun C 5.5. */ |
| if (subtract_p) |
| temp = -b->data; |
| else |
| temp = b->data; |
| |
| unsigned_p = UNSIGNED_FIXED_POINT_MODE_P (a->mode); |
| i_f_bits = GET_MODE_IBIT (a->mode) + GET_MODE_FBIT (a->mode); |
| f->mode = a->mode; |
| f->data = a->data + temp; |
| if (unsigned_p) /* Unsigned type. */ |
| { |
| if (subtract_p) /* Unsigned subtraction. */ |
| { |
| if (a->data.ult (b->data)) |
| { |
| if (sat_p) |
| { |
| f->data.high = 0; |
| f->data.low = 0; |
| } |
| else |
| overflow_p = true; |
| } |
| } |
| else /* Unsigned addition. */ |
| { |
| f->data = f->data.zext (i_f_bits); |
| if (f->data.ult (a->data) |
| || f->data.ult (b->data)) |
| { |
| if (sat_p) |
| { |
| f->data.high = -1; |
| f->data.low = -1; |
| } |
| else |
| overflow_p = true; |
| } |
| } |
| } |
| else /* Signed type. */ |
| { |
| if ((!subtract_p |
| && (get_fixed_sign_bit (a->data, i_f_bits) |
| == get_fixed_sign_bit (b->data, i_f_bits)) |
| && (get_fixed_sign_bit (a->data, i_f_bits) |
| != get_fixed_sign_bit (f->data, i_f_bits))) |
| || (subtract_p |
| && (get_fixed_sign_bit (a->data, i_f_bits) |
| != get_fixed_sign_bit (b->data, i_f_bits)) |
| && (get_fixed_sign_bit (a->data, i_f_bits) |
| != get_fixed_sign_bit (f->data, i_f_bits)))) |
| { |
| if (sat_p) |
| { |
| f->data.low = 1; |
| f->data.high = 0; |
| f->data = f->data.alshift (i_f_bits, HOST_BITS_PER_DOUBLE_INT); |
| if (get_fixed_sign_bit (a->data, i_f_bits) == 0) |
| { |
| --f->data; |
| } |
| } |
| else |
| overflow_p = true; |
| } |
| } |
| f->data = f->data.ext ((!unsigned_p) + i_f_bits, unsigned_p); |
| return overflow_p; |
| } |
| |
| /* Calculate F = A * B. |
| If SAT_P, saturate the result to the max or the min. |
| Return true, if !SAT_P and overflow. */ |
| |
| static bool |
| do_fixed_multiply (FIXED_VALUE_TYPE *f, const FIXED_VALUE_TYPE *a, |
| const FIXED_VALUE_TYPE *b, bool sat_p) |
| { |
| bool overflow_p = false; |
| bool unsigned_p = UNSIGNED_FIXED_POINT_MODE_P (a->mode); |
| int i_f_bits = GET_MODE_IBIT (a->mode) + GET_MODE_FBIT (a->mode); |
| f->mode = a->mode; |
| if (GET_MODE_PRECISION (f->mode) <= HOST_BITS_PER_WIDE_INT) |
| { |
| f->data = a->data * b->data; |
| f->data = f->data.lshift (-GET_MODE_FBIT (f->mode), |
| HOST_BITS_PER_DOUBLE_INT, !unsigned_p); |
| overflow_p = fixed_saturate1 (f->mode, f->data, &f->data, sat_p); |
| } |
| else |
| { |
| /* The result of multiplication expands to two double_int. */ |
| double_int a_high, a_low, b_high, b_low; |
| double_int high_high, high_low, low_high, low_low; |
| double_int r, s, temp1, temp2; |
| int carry = 0; |
| |
| /* Decompose a and b to four double_int. */ |
| a_high.low = a->data.high; |
| a_high.high = 0; |
| a_low.low = a->data.low; |
| a_low.high = 0; |
| b_high.low = b->data.high; |
| b_high.high = 0; |
| b_low.low = b->data.low; |
| b_low.high = 0; |
| |
| /* Perform four multiplications. */ |
| low_low = a_low * b_low; |
| low_high = a_low * b_high; |
| high_low = a_high * b_low; |
| high_high = a_high * b_high; |
| |
| /* Accumulate four results to {r, s}. */ |
| temp1.high = high_low.low; |
| temp1.low = 0; |
| s = low_low + temp1; |
| if (s.ult (low_low) |
| || s.ult (temp1)) |
| carry ++; /* Carry */ |
| temp1.high = s.high; |
| temp1.low = s.low; |
| temp2.high = low_high.low; |
| temp2.low = 0; |
| s = temp1 + temp2; |
| if (s.ult (temp1) |
| || s.ult (temp2)) |
| carry ++; /* Carry */ |
| |
| temp1.low = high_low.high; |
| temp1.high = 0; |
| r = high_high + temp1; |
| temp1.low = low_high.high; |
| temp1.high = 0; |
| r += temp1; |
| temp1.low = carry; |
| temp1.high = 0; |
| r += temp1; |
| |
| /* We need to subtract b from r, if a < 0. */ |
| if (!unsigned_p && a->data.high < 0) |
| r -= b->data; |
| /* We need to subtract a from r, if b < 0. */ |
| if (!unsigned_p && b->data.high < 0) |
| r -= a->data; |
| |
| /* Shift right the result by FBIT. */ |
| if (GET_MODE_FBIT (f->mode) == HOST_BITS_PER_DOUBLE_INT) |
| { |
| s.low = r.low; |
| s.high = r.high; |
| if (unsigned_p) |
| { |
| r.low = 0; |
| r.high = 0; |
| } |
| else |
| { |
| r.low = -1; |
| r.high = -1; |
| } |
| f->data.low = s.low; |
| f->data.high = s.high; |
| } |
| else |
| { |
| s = s.llshift ((-GET_MODE_FBIT (f->mode)), HOST_BITS_PER_DOUBLE_INT); |
| f->data = r.llshift ((HOST_BITS_PER_DOUBLE_INT |
| - GET_MODE_FBIT (f->mode)), |
| HOST_BITS_PER_DOUBLE_INT); |
| f->data.low = f->data.low | s.low; |
| f->data.high = f->data.high | s.high; |
| s.low = f->data.low; |
| s.high = f->data.high; |
| r = r.lshift (-GET_MODE_FBIT (f->mode), |
| HOST_BITS_PER_DOUBLE_INT, !unsigned_p); |
| } |
| |
| overflow_p = fixed_saturate2 (f->mode, r, s, &f->data, sat_p); |
| } |
| |
| f->data = f->data.ext ((!unsigned_p) + i_f_bits, unsigned_p); |
| return overflow_p; |
| } |
| |
| /* Calculate F = A / B. |
| If SAT_P, saturate the result to the max or the min. |
| Return true, if !SAT_P and overflow. */ |
| |
| static bool |
| do_fixed_divide (FIXED_VALUE_TYPE *f, const FIXED_VALUE_TYPE *a, |
| const FIXED_VALUE_TYPE *b, bool sat_p) |
| { |
| bool overflow_p = false; |
| bool unsigned_p = UNSIGNED_FIXED_POINT_MODE_P (a->mode); |
| int i_f_bits = GET_MODE_IBIT (a->mode) + GET_MODE_FBIT (a->mode); |
| f->mode = a->mode; |
| if (GET_MODE_PRECISION (f->mode) <= HOST_BITS_PER_WIDE_INT) |
| { |
| f->data = a->data.lshift (GET_MODE_FBIT (f->mode), |
| HOST_BITS_PER_DOUBLE_INT, !unsigned_p); |
| f->data = f->data.div (b->data, unsigned_p, TRUNC_DIV_EXPR); |
| overflow_p = fixed_saturate1 (f->mode, f->data, &f->data, sat_p); |
| } |
| else |
| { |
| double_int pos_a, pos_b, r, s; |
| double_int quo_r, quo_s, mod, temp; |
| int num_of_neg = 0; |
| int i; |
| |
| /* If a < 0, negate a. */ |
| if (!unsigned_p && a->data.high < 0) |
| { |
| pos_a = -a->data; |
| num_of_neg ++; |
| } |
| else |
| pos_a = a->data; |
| |
| /* If b < 0, negate b. */ |
| if (!unsigned_p && b->data.high < 0) |
| { |
| pos_b = -b->data; |
| num_of_neg ++; |
| } |
| else |
| pos_b = b->data; |
| |
| /* Left shift pos_a to {r, s} by FBIT. */ |
| if (GET_MODE_FBIT (f->mode) == HOST_BITS_PER_DOUBLE_INT) |
| { |
| r = pos_a; |
| s.high = 0; |
| s.low = 0; |
| } |
| else |
| { |
| s = pos_a.llshift (GET_MODE_FBIT (f->mode), HOST_BITS_PER_DOUBLE_INT); |
| r = pos_a.llshift (- (HOST_BITS_PER_DOUBLE_INT |
| - GET_MODE_FBIT (f->mode)), |
| HOST_BITS_PER_DOUBLE_INT); |
| } |
| |
| /* Divide r by pos_b to quo_r. The remainder is in mod. */ |
| quo_r = r.divmod (pos_b, 1, TRUNC_DIV_EXPR, &mod); |
| quo_s = double_int_zero; |
| |
| for (i = 0; i < HOST_BITS_PER_DOUBLE_INT; i++) |
| { |
| /* Record the leftmost bit of mod. */ |
| int leftmost_mod = (mod.high < 0); |
| |
| /* Shift left mod by 1 bit. */ |
| mod = mod.lshift (1); |
| |
| /* Test the leftmost bit of s to add to mod. */ |
| if (s.high < 0) |
| mod.low += 1; |
| |
| /* Shift left quo_s by 1 bit. */ |
| quo_s = quo_s.lshift (1); |
| |
| /* Try to calculate (mod - pos_b). */ |
| temp = mod - pos_b; |
| |
| if (leftmost_mod == 1 || mod.ucmp (pos_b) != -1) |
| { |
| quo_s.low += 1; |
| mod = temp; |
| } |
| |
| /* Shift left s by 1 bit. */ |
| s = s.lshift (1); |
| |
| } |
| |
| if (num_of_neg == 1) |
| { |
| quo_s = -quo_s; |
| if (quo_s.high == 0 && quo_s.low == 0) |
| quo_r = -quo_r; |
| else |
| { |
| quo_r.low = ~quo_r.low; |
| quo_r.high = ~quo_r.high; |
| } |
| } |
| |
| f->data = quo_s; |
| overflow_p = fixed_saturate2 (f->mode, quo_r, quo_s, &f->data, sat_p); |
| } |
| |
| f->data = f->data.ext ((!unsigned_p) + i_f_bits, unsigned_p); |
| return overflow_p; |
| } |
| |
| /* Calculate F = A << B if LEFT_P. Otherwise, F = A >> B. |
| If SAT_P, saturate the result to the max or the min. |
| Return true, if !SAT_P and overflow. */ |
| |
| static bool |
| do_fixed_shift (FIXED_VALUE_TYPE *f, const FIXED_VALUE_TYPE *a, |
| const FIXED_VALUE_TYPE *b, bool left_p, bool sat_p) |
| { |
| bool overflow_p = false; |
| bool unsigned_p = UNSIGNED_FIXED_POINT_MODE_P (a->mode); |
| int i_f_bits = GET_MODE_IBIT (a->mode) + GET_MODE_FBIT (a->mode); |
| f->mode = a->mode; |
| |
| if (b->data.low == 0) |
| { |
| f->data = a->data; |
| return overflow_p; |
| } |
| |
| if (GET_MODE_PRECISION (f->mode) <= HOST_BITS_PER_WIDE_INT || (!left_p)) |
| { |
| f->data = a->data.lshift (left_p ? b->data.low : -b->data.low, |
| HOST_BITS_PER_DOUBLE_INT, !unsigned_p); |
| if (left_p) /* Only left shift saturates. */ |
| overflow_p = fixed_saturate1 (f->mode, f->data, &f->data, sat_p); |
| } |
| else /* We need two double_int to store the left-shift result. */ |
| { |
| double_int temp_high, temp_low; |
| if (b->data.low == HOST_BITS_PER_DOUBLE_INT) |
| { |
| temp_high = a->data; |
| temp_low.high = 0; |
| temp_low.low = 0; |
| } |
| else |
| { |
| temp_low = a->data.lshift (b->data.low, |
| HOST_BITS_PER_DOUBLE_INT, !unsigned_p); |
| /* Logical shift right to temp_high. */ |
| temp_high = a->data.llshift (b->data.low - HOST_BITS_PER_DOUBLE_INT, |
| HOST_BITS_PER_DOUBLE_INT); |
| } |
| if (!unsigned_p && a->data.high < 0) /* Signed-extend temp_high. */ |
| temp_high = temp_high.ext (b->data.low, unsigned_p); |
| f->data = temp_low; |
| overflow_p = fixed_saturate2 (f->mode, temp_high, temp_low, &f->data, |
| sat_p); |
| } |
| f->data = f->data.ext ((!unsigned_p) + i_f_bits, unsigned_p); |
| return overflow_p; |
| } |
| |
| /* Calculate F = -A. |
| If SAT_P, saturate the result to the max or the min. |
| Return true, if !SAT_P and overflow. */ |
| |
| static bool |
| do_fixed_neg (FIXED_VALUE_TYPE *f, const FIXED_VALUE_TYPE *a, bool sat_p) |
| { |
| bool overflow_p = false; |
| bool unsigned_p = UNSIGNED_FIXED_POINT_MODE_P (a->mode); |
| int i_f_bits = GET_MODE_IBIT (a->mode) + GET_MODE_FBIT (a->mode); |
| f->mode = a->mode; |
| f->data = -a->data; |
| f->data = f->data.ext ((!unsigned_p) + i_f_bits, unsigned_p); |
| |
| if (unsigned_p) /* Unsigned type. */ |
| { |
| if (f->data.low != 0 || f->data.high != 0) |
| { |
| if (sat_p) |
| { |
| f->data.low = 0; |
| f->data.high = 0; |
| } |
| else |
| overflow_p = true; |
| } |
| } |
| else /* Signed type. */ |
| { |
| if (!(f->data.high == 0 && f->data.low == 0) |
| && f->data.high == a->data.high && f->data.low == a->data.low ) |
| { |
| if (sat_p) |
| { |
| /* Saturate to the maximum by subtracting f->data by one. */ |
| f->data.low = -1; |
| f->data.high = -1; |
| f->data = f->data.zext (i_f_bits); |
| } |
| else |
| overflow_p = true; |
| } |
| } |
| return overflow_p; |
| } |
| |
| /* Perform the binary or unary operation described by CODE. |
| Note that OP0 and OP1 must have the same mode for binary operators. |
| For a unary operation, leave OP1 NULL. |
| Return true, if !SAT_P and overflow. */ |
| |
| bool |
| fixed_arithmetic (FIXED_VALUE_TYPE *f, int icode, const FIXED_VALUE_TYPE *op0, |
| const FIXED_VALUE_TYPE *op1, bool sat_p) |
| { |
| switch (icode) |
| { |
| case NEGATE_EXPR: |
| return do_fixed_neg (f, op0, sat_p); |
| |
| case PLUS_EXPR: |
| gcc_assert (op0->mode == op1->mode); |
| return do_fixed_add (f, op0, op1, false, sat_p); |
| |
| case MINUS_EXPR: |
| gcc_assert (op0->mode == op1->mode); |
| return do_fixed_add (f, op0, op1, true, sat_p); |
| |
| case MULT_EXPR: |
| gcc_assert (op0->mode == op1->mode); |
| return do_fixed_multiply (f, op0, op1, sat_p); |
| |
| case TRUNC_DIV_EXPR: |
| gcc_assert (op0->mode == op1->mode); |
| return do_fixed_divide (f, op0, op1, sat_p); |
| |
| case LSHIFT_EXPR: |
| return do_fixed_shift (f, op0, op1, true, sat_p); |
| |
| case RSHIFT_EXPR: |
| return do_fixed_shift (f, op0, op1, false, sat_p); |
| |
| default: |
| gcc_unreachable (); |
| } |
| } |
| |
| /* Compare fixed-point values by tree_code. |
| Note that OP0 and OP1 must have the same mode. */ |
| |
| bool |
| fixed_compare (int icode, const FIXED_VALUE_TYPE *op0, |
| const FIXED_VALUE_TYPE *op1) |
| { |
| enum tree_code code = (enum tree_code) icode; |
| gcc_assert (op0->mode == op1->mode); |
| |
| switch (code) |
| { |
| case NE_EXPR: |
| return op0->data != op1->data; |
| |
| case EQ_EXPR: |
| return op0->data == op1->data; |
| |
| case LT_EXPR: |
| return op0->data.cmp (op1->data, |
| UNSIGNED_FIXED_POINT_MODE_P (op0->mode)) == -1; |
| |
| case LE_EXPR: |
| return op0->data.cmp (op1->data, |
| UNSIGNED_FIXED_POINT_MODE_P (op0->mode)) != 1; |
| |
| case GT_EXPR: |
| return op0->data.cmp (op1->data, |
| UNSIGNED_FIXED_POINT_MODE_P (op0->mode)) == 1; |
| |
| case GE_EXPR: |
| return op0->data.cmp (op1->data, |
| UNSIGNED_FIXED_POINT_MODE_P (op0->mode)) != -1; |
| |
| default: |
| gcc_unreachable (); |
| } |
| } |
| |
| /* Extend or truncate to a new mode. |
| If SAT_P, saturate the result to the max or the min. |
| Return true, if !SAT_P and overflow. */ |
| |
| bool |
| fixed_convert (FIXED_VALUE_TYPE *f, scalar_mode mode, |
| const FIXED_VALUE_TYPE *a, bool sat_p) |
| { |
| bool overflow_p = false; |
| if (mode == a->mode) |
| { |
| *f = *a; |
| return overflow_p; |
| } |
| |
| if (GET_MODE_FBIT (mode) > GET_MODE_FBIT (a->mode)) |
| { |
| /* Left shift a to temp_high, temp_low based on a->mode. */ |
| double_int temp_high, temp_low; |
| int amount = GET_MODE_FBIT (mode) - GET_MODE_FBIT (a->mode); |
| temp_low = a->data.lshift (amount, |
| HOST_BITS_PER_DOUBLE_INT, |
| SIGNED_FIXED_POINT_MODE_P (a->mode)); |
| /* Logical shift right to temp_high. */ |
| temp_high = a->data.llshift (amount - HOST_BITS_PER_DOUBLE_INT, |
| HOST_BITS_PER_DOUBLE_INT); |
| if (SIGNED_FIXED_POINT_MODE_P (a->mode) |
| && a->data.high < 0) /* Signed-extend temp_high. */ |
| temp_high = temp_high.sext (amount); |
| f->mode = mode; |
| f->data = temp_low; |
| if (SIGNED_FIXED_POINT_MODE_P (a->mode) == |
| SIGNED_FIXED_POINT_MODE_P (f->mode)) |
| overflow_p = fixed_saturate2 (f->mode, temp_high, temp_low, &f->data, |
| sat_p); |
| else |
| { |
| /* Take care of the cases when converting between signed and |
| unsigned. */ |
| if (SIGNED_FIXED_POINT_MODE_P (a->mode)) |
| { |
| /* Signed -> Unsigned. */ |
| if (a->data.high < 0) |
| { |
| if (sat_p) |
| { |
| f->data.low = 0; /* Set to zero. */ |
| f->data.high = 0; /* Set to zero. */ |
| } |
| else |
| overflow_p = true; |
| } |
| else |
| overflow_p = fixed_saturate2 (f->mode, temp_high, temp_low, |
| &f->data, sat_p); |
| } |
| else |
| { |
| /* Unsigned -> Signed. */ |
| if (temp_high.high < 0) |
| { |
| if (sat_p) |
| { |
| /* Set to maximum. */ |
| f->data.low = -1; /* Set to all ones. */ |
| f->data.high = -1; /* Set to all ones. */ |
| f->data = f->data.zext (GET_MODE_FBIT (f->mode) |
| + GET_MODE_IBIT (f->mode)); |
| /* Clear the sign. */ |
| } |
| else |
| overflow_p = true; |
| } |
| else |
| overflow_p = fixed_saturate2 (f->mode, temp_high, temp_low, |
| &f->data, sat_p); |
| } |
| } |
| } |
| else |
| { |
| /* Right shift a to temp based on a->mode. */ |
| double_int temp; |
| temp = a->data.lshift (GET_MODE_FBIT (mode) - GET_MODE_FBIT (a->mode), |
| HOST_BITS_PER_DOUBLE_INT, |
| SIGNED_FIXED_POINT_MODE_P (a->mode)); |
| f->mode = mode; |
| f->data = temp; |
| if (SIGNED_FIXED_POINT_MODE_P (a->mode) == |
| SIGNED_FIXED_POINT_MODE_P (f->mode)) |
| overflow_p = fixed_saturate1 (f->mode, f->data, &f->data, sat_p); |
| else |
| { |
| /* Take care of the cases when converting between signed and |
| unsigned. */ |
| if (SIGNED_FIXED_POINT_MODE_P (a->mode)) |
| { |
| /* Signed -> Unsigned. */ |
| if (a->data.high < 0) |
| { |
| if (sat_p) |
| { |
| f->data.low = 0; /* Set to zero. */ |
| f->data.high = 0; /* Set to zero. */ |
| } |
| else |
| overflow_p = true; |
| } |
| else |
| overflow_p = fixed_saturate1 (f->mode, f->data, &f->data, |
| sat_p); |
| } |
| else |
| { |
| /* Unsigned -> Signed. */ |
| if (temp.high < 0) |
| { |
| if (sat_p) |
| { |
| /* Set to maximum. */ |
| f->data.low = -1; /* Set to all ones. */ |
| f->data.high = -1; /* Set to all ones. */ |
| f->data = f->data.zext (GET_MODE_FBIT (f->mode) |
| + GET_MODE_IBIT (f->mode)); |
| /* Clear the sign. */ |
| } |
| else |
| overflow_p = true; |
| } |
| else |
| overflow_p = fixed_saturate1 (f->mode, f->data, &f->data, |
| sat_p); |
| } |
| } |
| } |
| |
| f->data = f->data.ext (SIGNED_FIXED_POINT_MODE_P (f->mode) |
| + GET_MODE_FBIT (f->mode) |
| + GET_MODE_IBIT (f->mode), |
| UNSIGNED_FIXED_POINT_MODE_P (f->mode)); |
| return overflow_p; |
| } |
| |
| /* Convert to a new fixed-point mode from an integer. |
| If UNSIGNED_P, this integer is unsigned. |
| If SAT_P, saturate the result to the max or the min. |
| Return true, if !SAT_P and overflow. */ |
| |
| bool |
| fixed_convert_from_int (FIXED_VALUE_TYPE *f, scalar_mode mode, |
| double_int a, bool unsigned_p, bool sat_p) |
| { |
| bool overflow_p = false; |
| /* Left shift a to temp_high, temp_low. */ |
| double_int temp_high, temp_low; |
| int amount = GET_MODE_FBIT (mode); |
| if (amount == HOST_BITS_PER_DOUBLE_INT) |
| { |
| temp_high = a; |
| temp_low.low = 0; |
| temp_low.high = 0; |
| } |
| else |
| { |
| temp_low = a.llshift (amount, HOST_BITS_PER_DOUBLE_INT); |
| |
| /* Logical shift right to temp_high. */ |
| temp_high = a.llshift (amount - HOST_BITS_PER_DOUBLE_INT, |
| HOST_BITS_PER_DOUBLE_INT); |
| } |
| if (!unsigned_p && a.high < 0) /* Signed-extend temp_high. */ |
| temp_high = temp_high.sext (amount); |
| |
| f->mode = mode; |
| f->data = temp_low; |
| |
| if (unsigned_p == UNSIGNED_FIXED_POINT_MODE_P (f->mode)) |
| overflow_p = fixed_saturate2 (f->mode, temp_high, temp_low, &f->data, |
| sat_p); |
| else |
| { |
| /* Take care of the cases when converting between signed and unsigned. */ |
| if (!unsigned_p) |
| { |
| /* Signed -> Unsigned. */ |
| if (a.high < 0) |
| { |
| if (sat_p) |
| { |
| f->data.low = 0; /* Set to zero. */ |
| f->data.high = 0; /* Set to zero. */ |
| } |
| else |
| overflow_p = true; |
| } |
| else |
| overflow_p = fixed_saturate2 (f->mode, temp_high, temp_low, |
| &f->data, sat_p); |
| } |
| else |
| { |
| /* Unsigned -> Signed. */ |
| if (temp_high.high < 0) |
| { |
| if (sat_p) |
| { |
| /* Set to maximum. */ |
| f->data.low = -1; /* Set to all ones. */ |
| f->data.high = -1; /* Set to all ones. */ |
| f->data = f->data.zext (GET_MODE_FBIT (f->mode) |
| + GET_MODE_IBIT (f->mode)); |
| /* Clear the sign. */ |
| } |
| else |
| overflow_p = true; |
| } |
| else |
| overflow_p = fixed_saturate2 (f->mode, temp_high, temp_low, |
| &f->data, sat_p); |
| } |
| } |
| f->data = f->data.ext (SIGNED_FIXED_POINT_MODE_P (f->mode) |
| + GET_MODE_FBIT (f->mode) |
| + GET_MODE_IBIT (f->mode), |
| UNSIGNED_FIXED_POINT_MODE_P (f->mode)); |
| return overflow_p; |
| } |
| |
| /* Convert to a new fixed-point mode from a real. |
| If SAT_P, saturate the result to the max or the min. |
| Return true, if !SAT_P and overflow. */ |
| |
| bool |
| fixed_convert_from_real (FIXED_VALUE_TYPE *f, scalar_mode mode, |
| const REAL_VALUE_TYPE *a, bool sat_p) |
| { |
| bool overflow_p = false; |
| REAL_VALUE_TYPE real_value, fixed_value, base_value; |
| bool unsigned_p = UNSIGNED_FIXED_POINT_MODE_P (mode); |
| int i_f_bits = GET_MODE_IBIT (mode) + GET_MODE_FBIT (mode); |
| unsigned int fbit = GET_MODE_FBIT (mode); |
| enum fixed_value_range_code temp; |
| bool fail; |
| |
| real_value = *a; |
| f->mode = mode; |
| real_2expN (&base_value, fbit, VOIDmode); |
| real_arithmetic (&fixed_value, MULT_EXPR, &real_value, &base_value); |
| |
| wide_int w = real_to_integer (&fixed_value, &fail, |
| GET_MODE_PRECISION (mode)); |
| f->data.low = w.ulow (); |
| f->data.high = w.elt (1); |
| temp = check_real_for_fixed_mode (&real_value, mode); |
| if (temp == FIXED_UNDERFLOW) /* Minimum. */ |
| { |
| if (sat_p) |
| { |
| if (unsigned_p) |
| { |
| f->data.low = 0; |
| f->data.high = 0; |
| } |
| else |
| { |
| f->data.low = 1; |
| f->data.high = 0; |
| f->data = f->data.alshift (i_f_bits, HOST_BITS_PER_DOUBLE_INT); |
| f->data = f->data.sext (1 + i_f_bits); |
| } |
| } |
| else |
| overflow_p = true; |
| } |
| else if (temp == FIXED_GT_MAX_EPS || temp == FIXED_MAX_EPS) /* Maximum. */ |
| { |
| if (sat_p) |
| { |
| f->data.low = -1; |
| f->data.high = -1; |
| f->data = f->data.zext (i_f_bits); |
| } |
| else |
| overflow_p = true; |
| } |
| f->data = f->data.ext ((!unsigned_p) + i_f_bits, unsigned_p); |
| return overflow_p; |
| } |
| |
| /* Convert to a new real mode from a fixed-point. */ |
| |
| void |
| real_convert_from_fixed (REAL_VALUE_TYPE *r, scalar_mode mode, |
| const FIXED_VALUE_TYPE *f) |
| { |
| REAL_VALUE_TYPE base_value, fixed_value, real_value; |
| |
| signop sgn = UNSIGNED_FIXED_POINT_MODE_P (f->mode) ? UNSIGNED : SIGNED; |
| real_2expN (&base_value, GET_MODE_FBIT (f->mode), VOIDmode); |
| real_from_integer (&fixed_value, VOIDmode, |
| wide_int::from (f->data, GET_MODE_PRECISION (f->mode), |
| sgn), sgn); |
| real_arithmetic (&real_value, RDIV_EXPR, &fixed_value, &base_value); |
| real_convert (r, mode, &real_value); |
| } |
| |
| /* Determine whether a fixed-point value F is negative. */ |
| |
| bool |
| fixed_isneg (const FIXED_VALUE_TYPE *f) |
| { |
| if (SIGNED_FIXED_POINT_MODE_P (f->mode)) |
| { |
| int i_f_bits = GET_MODE_IBIT (f->mode) + GET_MODE_FBIT (f->mode); |
| int sign_bit = get_fixed_sign_bit (f->data, i_f_bits); |
| if (sign_bit == 1) |
| return true; |
| } |
| |
| return false; |
| } |