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Diffstat (limited to 'gcc/fixed-value.cc')
| -rw-r--r-- | gcc/fixed-value.cc | 1120 |
1 files changed, 1120 insertions, 0 deletions
diff --git a/gcc/fixed-value.cc b/gcc/fixed-value.cc new file mode 100644 index 0000000..655edd3 --- /dev/null +++ b/gcc/fixed-value.cc @@ -0,0 +1,1120 @@ +/* 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; +} |