qemu/disas/libvixl/vixl/utils.cc

143 lines
3.9 KiB
C++

// Copyright 2015, ARM Limited
// All rights reserved.
//
// Redistribution and use in source and binary forms, with or without
// modification, are permitted provided that the following conditions are met:
//
// * Redistributions of source code must retain the above copyright notice,
// this list of conditions and the following disclaimer.
// * Redistributions in binary form must reproduce the above copyright notice,
// this list of conditions and the following disclaimer in the documentation
// and/or other materials provided with the distribution.
// * Neither the name of ARM Limited nor the names of its contributors may be
// used to endorse or promote products derived from this software without
// specific prior written permission.
//
// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS CONTRIBUTORS "AS IS" AND
// ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
// WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
// DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE
// FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
// DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
// SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
// CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
// OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
#include "vixl/utils.h"
#include <stdio.h>
namespace vixl {
uint32_t float_to_rawbits(float value) {
uint32_t bits = 0;
memcpy(&bits, &value, 4);
return bits;
}
uint64_t double_to_rawbits(double value) {
uint64_t bits = 0;
memcpy(&bits, &value, 8);
return bits;
}
float rawbits_to_float(uint32_t bits) {
float value = 0.0;
memcpy(&value, &bits, 4);
return value;
}
double rawbits_to_double(uint64_t bits) {
double value = 0.0;
memcpy(&value, &bits, 8);
return value;
}
uint32_t float_sign(float val) {
uint32_t rawbits = float_to_rawbits(val);
return unsigned_bitextract_32(31, 31, rawbits);
}
uint32_t float_exp(float val) {
uint32_t rawbits = float_to_rawbits(val);
return unsigned_bitextract_32(30, 23, rawbits);
}
uint32_t float_mantissa(float val) {
uint32_t rawbits = float_to_rawbits(val);
return unsigned_bitextract_32(22, 0, rawbits);
}
uint32_t double_sign(double val) {
uint64_t rawbits = double_to_rawbits(val);
return static_cast<uint32_t>(unsigned_bitextract_64(63, 63, rawbits));
}
uint32_t double_exp(double val) {
uint64_t rawbits = double_to_rawbits(val);
return static_cast<uint32_t>(unsigned_bitextract_64(62, 52, rawbits));
}
uint64_t double_mantissa(double val) {
uint64_t rawbits = double_to_rawbits(val);
return unsigned_bitextract_64(51, 0, rawbits);
}
float float_pack(uint32_t sign, uint32_t exp, uint32_t mantissa) {
uint32_t bits = (sign << 31) | (exp << 23) | mantissa;
return rawbits_to_float(bits);
}
double double_pack(uint64_t sign, uint64_t exp, uint64_t mantissa) {
uint64_t bits = (sign << 63) | (exp << 52) | mantissa;
return rawbits_to_double(bits);
}
int float16classify(float16 value) {
uint16_t exponent_max = (1 << 5) - 1;
uint16_t exponent_mask = exponent_max << 10;
uint16_t mantissa_mask = (1 << 10) - 1;
uint16_t exponent = (value & exponent_mask) >> 10;
uint16_t mantissa = value & mantissa_mask;
if (exponent == 0) {
if (mantissa == 0) {
return FP_ZERO;
}
return FP_SUBNORMAL;
} else if (exponent == exponent_max) {
if (mantissa == 0) {
return FP_INFINITE;
}
return FP_NAN;
}
return FP_NORMAL;
}
unsigned CountClearHalfWords(uint64_t imm, unsigned reg_size) {
VIXL_ASSERT((reg_size % 8) == 0);
int count = 0;
for (unsigned i = 0; i < (reg_size / 16); i++) {
if ((imm & 0xffff) == 0) {
count++;
}
imm >>= 16;
}
return count;
}
} // namespace vixl