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- // Copyright (c) 2015-2016 The Khronos Group Inc.
- //
- // Licensed under the Apache License, Version 2.0 (the "License");
- // you may not use this file except in compliance with the License.
- // You may obtain a copy of the License at
- //
- // http://www.apache.org/licenses/LICENSE-2.0
- //
- // Unless required by applicable law or agreed to in writing, software
- // distributed under the License is distributed on an "AS IS" BASIS,
- // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- // See the License for the specific language governing permissions and
- // limitations under the License.
- #include "source/spirv_endian.h"
- #include <cstring>
- enum {
- I32_ENDIAN_LITTLE = 0x03020100ul,
- I32_ENDIAN_BIG = 0x00010203ul,
- };
- // This constant value allows the detection of the host machine's endianness.
- // Accessing it through the "value" member is valid due to C++11 section 3.10
- // paragraph 10.
- static const union {
- unsigned char bytes[4];
- uint32_t value;
- } o32_host_order = {{0, 1, 2, 3}};
- #define I32_ENDIAN_HOST (o32_host_order.value)
- uint32_t spvFixWord(const uint32_t word, const spv_endianness_t endian) {
- if ((SPV_ENDIANNESS_LITTLE == endian && I32_ENDIAN_HOST == I32_ENDIAN_BIG) ||
- (SPV_ENDIANNESS_BIG == endian && I32_ENDIAN_HOST == I32_ENDIAN_LITTLE)) {
- return (word & 0x000000ff) << 24 | (word & 0x0000ff00) << 8 |
- (word & 0x00ff0000) >> 8 | (word & 0xff000000) >> 24;
- }
- return word;
- }
- uint64_t spvFixDoubleWord(const uint32_t low, const uint32_t high,
- const spv_endianness_t endian) {
- return (uint64_t(spvFixWord(high, endian)) << 32) | spvFixWord(low, endian);
- }
- spv_result_t spvBinaryEndianness(spv_const_binary binary,
- spv_endianness_t* pEndian) {
- if (!binary->code || !binary->wordCount) return SPV_ERROR_INVALID_BINARY;
- if (!pEndian) return SPV_ERROR_INVALID_POINTER;
- uint8_t bytes[4];
- memcpy(bytes, binary->code, sizeof(uint32_t));
- if (0x03 == bytes[0] && 0x02 == bytes[1] && 0x23 == bytes[2] &&
- 0x07 == bytes[3]) {
- *pEndian = SPV_ENDIANNESS_LITTLE;
- return SPV_SUCCESS;
- }
- if (0x07 == bytes[0] && 0x23 == bytes[1] && 0x02 == bytes[2] &&
- 0x03 == bytes[3]) {
- *pEndian = SPV_ENDIANNESS_BIG;
- return SPV_SUCCESS;
- }
- return SPV_ERROR_INVALID_BINARY;
- }
- bool spvIsHostEndian(spv_endianness_t endian) {
- return ((SPV_ENDIANNESS_LITTLE == endian) &&
- (I32_ENDIAN_LITTLE == I32_ENDIAN_HOST)) ||
- ((SPV_ENDIANNESS_BIG == endian) &&
- (I32_ENDIAN_BIG == I32_ENDIAN_HOST));
- }
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