165 lines
4.9 KiB
C++
165 lines
4.9 KiB
C++
// Copyright 2017 The Dawn Authors
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//
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// Licensed under the Apache License, Version 2.0 (the "License");
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// you may not use this file except in compliance with the License.
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// You may obtain a copy of the License at
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//
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// http://www.apache.org/licenses/LICENSE-2.0
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//
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// Unless required by applicable law or agreed to in writing, software
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// distributed under the License is distributed on an "AS IS" BASIS,
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// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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// See the License for the specific language governing permissions and
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// limitations under the License.
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#include "dawn/common/Math.h"
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#include <algorithm>
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#include <cmath>
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#include <limits>
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#include "dawn/common/Assert.h"
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#include "dawn/common/Platform.h"
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#if DAWN_COMPILER_IS(MSVC)
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#include <intrin.h>
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#endif
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uint32_t ScanForward(uint32_t bits) {
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ASSERT(bits != 0);
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#if DAWN_COMPILER_IS(MSVC)
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// NOLINTNEXTLINE(runtime/int)
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unsigned long firstBitIndex = 0ul;
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unsigned char ret = _BitScanForward(&firstBitIndex, bits);
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ASSERT(ret != 0);
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return firstBitIndex;
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#else
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return static_cast<uint32_t>(__builtin_ctz(bits));
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#endif
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}
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uint32_t Log2(uint32_t value) {
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ASSERT(value != 0);
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#if DAWN_COMPILER_IS(MSVC)
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// NOLINTNEXTLINE(runtime/int)
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unsigned long firstBitIndex = 0ul;
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unsigned char ret = _BitScanReverse(&firstBitIndex, value);
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ASSERT(ret != 0);
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return firstBitIndex;
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#else
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return 31 - static_cast<uint32_t>(__builtin_clz(value));
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#endif
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}
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uint32_t Log2(uint64_t value) {
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ASSERT(value != 0);
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#if DAWN_COMPILER_IS(MSVC)
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#if DAWN_PLATFORM_IS(64_BIT)
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// NOLINTNEXTLINE(runtime/int)
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unsigned long firstBitIndex = 0ul;
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unsigned char ret = _BitScanReverse64(&firstBitIndex, value);
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ASSERT(ret != 0);
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return firstBitIndex;
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#else // DAWN_PLATFORM_IS(64_BIT)
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// NOLINTNEXTLINE(runtime/int)
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unsigned long firstBitIndex = 0ul;
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if (_BitScanReverse(&firstBitIndex, value >> 32)) {
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return firstBitIndex + 32;
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}
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unsigned char ret = _BitScanReverse(&firstBitIndex, value & 0xFFFFFFFF);
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ASSERT(ret != 0);
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return firstBitIndex;
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#endif // DAWN_PLATFORM_IS(64_BIT)
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#else // DAWN_COMPILER_IS(MSVC)
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return 63 - static_cast<uint32_t>(__builtin_clzll(value));
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#endif // DAWN_COMPILER_IS(MSVC)
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}
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uint64_t NextPowerOfTwo(uint64_t n) {
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if (n <= 1) {
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return 1;
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}
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return 1ull << (Log2(n - 1) + 1);
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}
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bool IsPowerOfTwo(uint64_t n) {
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ASSERT(n != 0);
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return (n & (n - 1)) == 0;
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}
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bool IsPtrAligned(const void* ptr, size_t alignment) {
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ASSERT(IsPowerOfTwo(alignment));
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ASSERT(alignment != 0);
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return (reinterpret_cast<size_t>(ptr) & (alignment - 1)) == 0;
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}
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bool IsAligned(uint32_t value, size_t alignment) {
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ASSERT(alignment <= UINT32_MAX);
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ASSERT(IsPowerOfTwo(alignment));
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ASSERT(alignment != 0);
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uint32_t alignment32 = static_cast<uint32_t>(alignment);
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return (value & (alignment32 - 1)) == 0;
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}
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uint16_t Float32ToFloat16(float fp32) {
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uint32_t fp32i = BitCast<uint32_t>(fp32);
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uint32_t sign16 = (fp32i & 0x80000000) >> 16;
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uint32_t mantissaAndExponent = fp32i & 0x7FFFFFFF;
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if (mantissaAndExponent > 0x7F800000) { // NaN
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return 0x7FFF;
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} else if (mantissaAndExponent > 0x47FFEFFF) { // Infinity
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return static_cast<uint16_t>(sign16 | 0x7C00);
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} else if (mantissaAndExponent < 0x38800000) { // Denormal
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uint32_t mantissa = (mantissaAndExponent & 0x007FFFFF) | 0x00800000;
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int32_t exponent = 113 - (mantissaAndExponent >> 23);
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if (exponent < 24) {
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mantissaAndExponent = mantissa >> exponent;
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} else {
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mantissaAndExponent = 0;
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}
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return static_cast<uint16_t>(
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sign16 | (mantissaAndExponent + 0x00000FFF + ((mantissaAndExponent >> 13) & 1)) >> 13);
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} else {
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return static_cast<uint16_t>(sign16 | (mantissaAndExponent + 0xC8000000 + 0x00000FFF +
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((mantissaAndExponent >> 13) & 1)) >>
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13);
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}
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}
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float Float16ToFloat32(uint16_t fp16) {
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uint32_t tmp = (fp16 & 0x7fff) << 13 | (fp16 & 0x8000) << 16;
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float tmp2 = *reinterpret_cast<float*>(&tmp);
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return pow(2, 127 - 15) * tmp2;
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}
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bool IsFloat16NaN(uint16_t fp16) {
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return (fp16 & 0x7FFF) > 0x7C00;
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}
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// Based on the Khronos Data Format Specification 1.2 Section 13.3 sRGB transfer functions
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float SRGBToLinear(float srgb) {
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// sRGB is always used in unsigned normalized formats so clamp to [0.0, 1.0]
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if (srgb <= 0.0f) {
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return 0.0f;
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} else if (srgb > 1.0f) {
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return 1.0f;
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}
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if (srgb < 0.04045f) {
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return srgb / 12.92f;
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} else {
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return std::pow((srgb + 0.055f) / 1.055f, 2.4f);
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}
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}
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uint64_t RoundUp(uint64_t n, uint64_t m) {
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ASSERT(m > 0);
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ASSERT(n > 0);
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ASSERT(m <= std::numeric_limits<uint64_t>::max() - n);
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return ((n + m - 1) / m) * m;
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}
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