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gnu / gcc / cd99b30c7cf1e68ef76ed2af7a41ac74c78116fe / . / gcc / fixed-value.c
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/* Fixed-point arithmetic support.
Copyright (C) 2006, 2007, 2008 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 "toplev.h"
#include "fixed-value.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, enum machine_mode mode)
{
REAL_VALUE_TYPE max_value, min_value, epsilon_value;
real_2expN (&max_value, GET_MODE_IBIT (mode), mode);
real_2expN (&epsilon_value, -GET_MODE_FBIT (mode), mode);
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;
}
/* Initialize from a decimal or hexadecimal string. */
void
fixed_from_string (FIXED_VALUE_TYPE *f, const char *str, enum machine_mode mode)
{
REAL_VALUE_TYPE real_value, fixed_value, base_value;
unsigned int fbit;
enum fixed_value_range_code temp;
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, mode);
real_arithmetic (&fixed_value, MULT_EXPR, &real_value, &base_value);
real_to_integer2 ((HOST_WIDE_INT *)&f->data.low, &f->data.high,
&fixed_value);
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 = double_int_ext (f->data,
GET_MODE_FBIT (f->mode)
+ GET_MODE_IBIT (f->mode), 1);
}
else
f->data = double_int_ext (f->data,
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;
real_2expN (&base_value, GET_MODE_FBIT (f_orig->mode), f_orig->mode);
real_from_integer (&real_value, VOIDmode, f_orig->data.low, f_orig->data.high,
UNSIGNED_FIXED_POINT_MODE_P (f_orig->mode));
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 (enum 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 = double_int_ext (max, i_f_bits, 1);
if (double_int_cmp (a, max, 1) == 1)
{
if (sat_p)
*f = max;
else
overflow_p = true;
}
}
else /* Signed type. */
{
double_int max, min;
max.high = -1;
max.low = -1;
max = double_int_ext (max, i_f_bits, 1);
min.high = 0;
min.low = 1;
lshift_double (min.low, min.high, i_f_bits,
2 * HOST_BITS_PER_WIDE_INT,
&min.low, &min.high, 1);
min = double_int_ext (min, 1 + i_f_bits, 0);
if (double_int_cmp (a, max, 0) == 1)
{
if (sat_p)
*f = max;
else
overflow_p = true;
}
else if (double_int_cmp (a, min, 0) == -1)
{
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 (enum 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 = double_int_ext (max_s, i_f_bits, 1);
if (double_int_cmp (a_high, max_r, 1) == 1
|| (double_int_equal_p (a_high, max_r) &&
double_int_cmp (a_low, max_s, 1) == 1))
{
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 = double_int_ext (max_s, i_f_bits, 1);
min_r.high = -1;
min_r.low = -1;
min_s.high = 0;
min_s.low = 1;
lshift_double (min_s.low, min_s.high, i_f_bits,
2 * HOST_BITS_PER_WIDE_INT,
&min_s.low, &min_s.high, 1);
min_s = double_int_ext (min_s, 1 + i_f_bits, 0);
if (double_int_cmp (a_high, max_r, 0) == 1
|| (double_int_equal_p (a_high, max_r) &&
double_int_cmp (a_low, max_s, 1) == 1))
{
if (sat_p)
*f = max_s;
else
overflow_p = true;
}
else if (double_int_cmp (a_high, min_r, 0) == -1
|| (double_int_equal_p (a_high, min_r) &&
double_int_cmp (a_low, min_s, 1) == -1))
{
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 = double_int_neg (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 = double_int_add (a->data, temp);
if (unsigned_p) /* Unsigned type. */
{
if (subtract_p) /* Unsigned subtraction. */
{
if (double_int_cmp (a->data, b->data, 1) == -1)
{
if (sat_p)
{
f->data.high = 0;
f->data.low = 0;
}
else
overflow_p = true;
}
}
else /* Unsigned addition. */
{
f->data = double_int_ext (f->data, i_f_bits, 1);
if (double_int_cmp (f->data, a->data, 1) == -1
|| double_int_cmp (f->data, b->data, 1) == -1)
{
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;
lshift_double (f->data.low, f->data.high, i_f_bits,
2 * HOST_BITS_PER_WIDE_INT,
&f->data.low, &f->data.high, 1);
if (get_fixed_sign_bit (a->data, i_f_bits) == 0)
{
double_int one;
one.low = 1;
one.high = 0;
f->data = double_int_add (f->data, double_int_neg (one));
}
}
else
overflow_p = true;
}
}
f->data = double_int_ext (f->data, (!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 = double_int_mul (a->data, b->data);
lshift_double (f->data.low, f->data.high,
(-GET_MODE_FBIT (f->mode)),
2 * HOST_BITS_PER_WIDE_INT,
&f->data.low, &f->data.high, !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 = double_int_mul (a_low, b_low);
low_high = double_int_mul (a_low, b_high);
high_low = double_int_mul (a_high, b_low);
high_high = double_int_mul (a_high, b_high);
/* Accumulate four results to {r, s}. */
temp1.high = high_low.low;
temp1.low = 0;
s = double_int_add (low_low, temp1);
if (double_int_cmp (s, low_low, 1) == -1
|| double_int_cmp (s, temp1, 1) == -1)
carry ++; /* Carry */
temp1.high = s.high;
temp1.low = s.low;
temp2.high = low_high.low;
temp2.low = 0;
s = double_int_add (temp1, temp2);
if (double_int_cmp (s, temp1, 1) == -1
|| double_int_cmp (s, temp2, 1) == -1)
carry ++; /* Carry */
temp1.low = high_low.high;
temp1.high = 0;
r = double_int_add (high_high, temp1);
temp1.low = low_high.high;
temp1.high = 0;
r = double_int_add (r, temp1);
temp1.low = carry;
temp1.high = 0;
r = double_int_add (r, temp1);
/* We need to add neg(b) to r, if a < 0. */
if (!unsigned_p && a->data.high < 0)
r = double_int_add (r, double_int_neg (b->data));
/* We need to add neg(a) to r, if b < 0. */
if (!unsigned_p && b->data.high < 0)
r = double_int_add (r, double_int_neg (a->data));
/* Shift right the result by FBIT. */
if (GET_MODE_FBIT (f->mode) == 2 * HOST_BITS_PER_WIDE_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
{
lshift_double (s.low, s.high,
(-GET_MODE_FBIT (f->mode)),
2 * HOST_BITS_PER_WIDE_INT,
&s.low, &s.high, 0);
lshift_double (r.low, r.high,
(2 * HOST_BITS_PER_WIDE_INT
- GET_MODE_FBIT (f->mode)),
2 * HOST_BITS_PER_WIDE_INT,
&f->data.low, &f->data.high, 0);
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;
lshift_double (r.low, r.high,
(-GET_MODE_FBIT (f->mode)),
2 * HOST_BITS_PER_WIDE_INT,
&r.low, &r.high, !unsigned_p);
}
overflow_p = fixed_saturate2 (f->mode, r, s, &f->data, sat_p);
}
f->data = double_int_ext (f->data, (!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)
{
lshift_double (a->data.low, a->data.high,
GET_MODE_FBIT (f->mode),
2 * HOST_BITS_PER_WIDE_INT,
&f->data.low, &f->data.high, !unsigned_p);
f->data = double_int_div (f->data, 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 = double_int_neg (a->data);
num_of_neg ++;
}
else
pos_a = a->data;
/* If b < 0, negate b. */
if (!unsigned_p && b->data.high < 0)
{
pos_b = double_int_neg (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) == 2 * HOST_BITS_PER_WIDE_INT)
{
r = pos_a;
s.high = 0;
s.low = 0;
}
else
{
lshift_double (pos_a.low, pos_a.high,
GET_MODE_FBIT (f->mode),
2 * HOST_BITS_PER_WIDE_INT,
&s.low, &s.high, 0);
lshift_double (pos_a.low, pos_a.high,
- (2 * HOST_BITS_PER_WIDE_INT
- GET_MODE_FBIT (f->mode)),
2 * HOST_BITS_PER_WIDE_INT,
&r.low, &r.high, 0);
}
/* Divide r by pos_b to quo_r. The remainder is in mod. */
div_and_round_double (TRUNC_DIV_EXPR, 1, r.low, r.high, pos_b.low,
pos_b.high, &quo_r.low, &quo_r.high, &mod.low,
&mod.high);
quo_s.high = 0;
quo_s.low = 0;
for (i = 0; i < 2 * HOST_BITS_PER_WIDE_INT; i++)
{
/* Record the leftmost bit of mod. */
int leftmost_mod = (mod.high < 0);
/* Shift left mod by 1 bit. */
lshift_double (mod.low, mod.high, 1, 2 * HOST_BITS_PER_WIDE_INT,
&mod.low, &mod.high, 0);
/* Test the leftmost bit of s to add to mod. */
if (s.high < 0)
mod.low += 1;
/* Shift left quo_s by 1 bit. */
lshift_double (quo_s.low, quo_s.high, 1, 2 * HOST_BITS_PER_WIDE_INT,
&quo_s.low, &quo_s.high, 0);
/* Try to calculate (mod - pos_b). */
temp = double_int_add (mod, double_int_neg (pos_b));
if (leftmost_mod == 1 || double_int_cmp (mod, pos_b, 1) != -1)
{
quo_s.low += 1;
mod = temp;
}
/* Shift left s by 1 bit. */
lshift_double (s.low, s.high, 1, 2 * HOST_BITS_PER_WIDE_INT,
&s.low, &s.high, 0);
}
if (num_of_neg == 1)
{
quo_s = double_int_neg (quo_s);
if (quo_s.high == 0 && quo_s.low == 0)
quo_r = double_int_neg (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 = double_int_ext (f->data, (!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))
{
lshift_double (a->data.low, a->data.high,
left_p ? b->data.low : (-b->data.low),
2 * HOST_BITS_PER_WIDE_INT,
&f->data.low, &f->data.high, !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 == 2 * HOST_BITS_PER_WIDE_INT)
{
temp_high = a->data;
temp_low.high = 0;
temp_low.low = 0;
}
else
{
lshift_double (a->data.low, a->data.high,
b->data.low,
2 * HOST_BITS_PER_WIDE_INT,
&temp_low.low, &temp_low.high, !unsigned_p);
/* Logical shift right to temp_high. */
lshift_double (a->data.low, a->data.high,
b->data.low - 2 * HOST_BITS_PER_WIDE_INT,
2 * HOST_BITS_PER_WIDE_INT,
&temp_high.low, &temp_high.high, 0);
}
if (!unsigned_p && a->data.high < 0) /* Signed-extend temp_high. */
temp_high = double_int_ext (temp_high, 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 = double_int_ext (f->data, (!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 = double_int_neg (a->data);
f->data = double_int_ext (f->data, (!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 = double_int_ext (f->data, i_f_bits, 1);
}
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);
break;
case PLUS_EXPR:
gcc_assert (op0->mode == op1->mode);
return do_fixed_add (f, op0, op1, false, sat_p);
break;
case MINUS_EXPR:
gcc_assert (op0->mode == op1->mode);
return do_fixed_add (f, op0, op1, true, sat_p);
break;
case MULT_EXPR:
gcc_assert (op0->mode == op1->mode);
return do_fixed_multiply (f, op0, op1, sat_p);
break;
case TRUNC_DIV_EXPR:
gcc_assert (op0->mode == op1->mode);
return do_fixed_divide (f, op0, op1, sat_p);
break;
case LSHIFT_EXPR:
return do_fixed_shift (f, op0, op1, true, sat_p);
break;
case RSHIFT_EXPR:
return do_fixed_shift (f, op0, op1, false, sat_p);
break;
default:
gcc_unreachable ();
}
return false;
}
/* 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 = icode;
gcc_assert (op0->mode == op1->mode);
switch (code)
{
case NE_EXPR:
return !double_int_equal_p (op0->data, op1->data);
case EQ_EXPR:
return double_int_equal_p (op0->data, op1->data);
case LT_EXPR:
return double_int_cmp (op0->data, op1->data,
UNSIGNED_FIXED_POINT_MODE_P (op0->mode)) == -1;
case LE_EXPR:
return double_int_cmp (op0->data, op1->data,
UNSIGNED_FIXED_POINT_MODE_P (op0->mode)) != 1;
case GT_EXPR:
return double_int_cmp (op0->data, op1->data,
UNSIGNED_FIXED_POINT_MODE_P (op0->mode)) == 1;
case GE_EXPR:
return double_int_cmp (op0->data, 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, enum machine_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);
lshift_double (a->data.low, a->data.high,
amount,
2 * HOST_BITS_PER_WIDE_INT,
&temp_low.low, &temp_low.high,
SIGNED_FIXED_POINT_MODE_P (a->mode));
/* Logical shift right to temp_high. */
lshift_double (a->data.low, a->data.high,
amount - 2 * HOST_BITS_PER_WIDE_INT,
2 * HOST_BITS_PER_WIDE_INT,
&temp_high.low, &temp_high.high, 0);
if (SIGNED_FIXED_POINT_MODE_P (a->mode)
&& a->data.high < 0) /* Signed-extend temp_high. */
temp_high = double_int_ext (temp_high, amount, 0);
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 = double_int_ext (f->data,
GET_MODE_FBIT (f->mode)
+ GET_MODE_IBIT (f->mode),
1); /* 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;
lshift_double (a->data.low, a->data.high,
GET_MODE_FBIT (mode) - GET_MODE_FBIT (a->mode),
2 * HOST_BITS_PER_WIDE_INT,
&temp.low, &temp.high,
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 = double_int_ext (f->data,
GET_MODE_FBIT (f->mode)
+ GET_MODE_IBIT (f->mode),
1); /* Clear the sign. */
}
else
overflow_p = true;
}
else
overflow_p = fixed_saturate1 (f->mode, f->data, &f->data,
sat_p);
}
}
}
f->data = double_int_ext (f->data,
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, enum machine_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 == 2 * HOST_BITS_PER_WIDE_INT)
{
temp_high = a;
temp_low.low = 0;
temp_low.high = 0;
}
else
{
lshift_double (a.low, a.high,
amount,
2 * HOST_BITS_PER_WIDE_INT,
&temp_low.low, &temp_low.high, 0);
/* Logical shift right to temp_high. */
lshift_double (a.low, a.high,
amount - 2 * HOST_BITS_PER_WIDE_INT,
2 * HOST_BITS_PER_WIDE_INT,
&temp_high.low, &temp_high.high, 0);
}
if (!unsigned_p && a.high < 0) /* Signed-extend temp_high. */
temp_high = double_int_ext (temp_high, amount, 0);
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 = double_int_ext (f->data,
GET_MODE_FBIT (f->mode)
+ GET_MODE_IBIT (f->mode),
1); /* Clear the sign. */
}
else
overflow_p = true;
}
else
overflow_p = fixed_saturate2 (f->mode, temp_high, temp_low,
&f->data, sat_p);
}
}
f->data = double_int_ext (f->data,
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, enum machine_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;
real_value = *a;
f->mode = mode;
real_2expN (&base_value, fbit, mode);
real_arithmetic (&fixed_value, MULT_EXPR, &real_value, &base_value);
real_to_integer2 ((HOST_WIDE_INT *)&f->data.low, &f->data.high, &fixed_value);
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;
lshift_double (f->data.low, f->data.high, i_f_bits,
2 * HOST_BITS_PER_WIDE_INT,
&f->data.low, &f->data.high, 1);
f->data = double_int_ext (f->data, 1 + i_f_bits, 0);
}
}
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 = double_int_ext (f->data, i_f_bits, 1);
}
else
overflow_p = true;
}
f->data = double_int_ext (f->data, (!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, enum machine_mode mode,
const FIXED_VALUE_TYPE *f)
{
REAL_VALUE_TYPE base_value, fixed_value, real_value;
real_2expN (&base_value, GET_MODE_FBIT (f->mode), f->mode);
real_from_integer (&fixed_value, VOIDmode, f->data.low, f->data.high,
UNSIGNED_FIXED_POINT_MODE_P (f->mode));
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;
}