+++ /dev/null
-// Copyright 2013, 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 "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;
-}
-
-
-int CountLeadingZeros(uint64_t value, int width) {
- VIXL_ASSERT((width == 32) || (width == 64));
- int count = 0;
- uint64_t bit_test = UINT64_C(1) << (width - 1);
- while ((count < width) && ((bit_test & value) == 0)) {
- count++;
- bit_test >>= 1;
- }
- return count;
-}
-
-
-int CountLeadingSignBits(int64_t value, int width) {
- VIXL_ASSERT((width == 32) || (width == 64));
- if (value >= 0) {
- return CountLeadingZeros(value, width) - 1;
- } else {
- return CountLeadingZeros(~value, width) - 1;
- }
-}
-
-
-int CountTrailingZeros(uint64_t value, int width) {
- VIXL_ASSERT((width == 32) || (width == 64));
- int count = 0;
- while ((count < width) && (((value >> count) & 1) == 0)) {
- count++;
- }
- return count;
-}
-
-
-int CountSetBits(uint64_t value, int width) {
- // TODO: Other widths could be added here, as the implementation already
- // supports them.
- VIXL_ASSERT((width == 32) || (width == 64));
-
- // Mask out unused bits to ensure that they are not counted.
- value &= (UINT64_C(0xffffffffffffffff) >> (64-width));
-
- // Add up the set bits.
- // The algorithm works by adding pairs of bit fields together iteratively,
- // where the size of each bit field doubles each time.
- // An example for an 8-bit value:
- // Bits: h g f e d c b a
- // \ | \ | \ | \ |
- // value = h+g f+e d+c b+a
- // \ | \ |
- // value = h+g+f+e d+c+b+a
- // \ |
- // value = h+g+f+e+d+c+b+a
- const uint64_t kMasks[] = {
- UINT64_C(0x5555555555555555),
- UINT64_C(0x3333333333333333),
- UINT64_C(0x0f0f0f0f0f0f0f0f),
- UINT64_C(0x00ff00ff00ff00ff),
- UINT64_C(0x0000ffff0000ffff),
- UINT64_C(0x00000000ffffffff),
- };
-
- for (unsigned i = 0; i < (sizeof(kMasks) / sizeof(kMasks[0])); i++) {
- int shift = 1 << i;
- value = ((value >> shift) & kMasks[i]) + (value & kMasks[i]);
- }
-
- return value;
-}
-
-
-uint64_t LowestSetBit(uint64_t value) {
- return value & -value;
-}
-
-
-bool IsPowerOf2(int64_t value) {
- return (value != 0) && ((value & (value - 1)) == 0);
-}
-
-
-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
Code Review / kvmfornfv.git / blobdiff