| // Copyright 2017 The Dawn & Tint Authors |
| // |
| // Redistribution and use in source and binary forms, with or without |
| // modification, are permitted provided that the following conditions are met: |
| // |
| // 1. Redistributions of source code must retain the above copyright notice, this |
| // list of conditions and the following disclaimer. |
| // |
| // 2. 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. |
| // |
| // 3. Neither the name of the copyright holder 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 AND 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 HOLDER 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 "dawn/common/Math.h" |
| |
| #include <algorithm> |
| #include <cmath> |
| #include <limits> |
| |
| #include "dawn/common/Assert.h" |
| #include "dawn/common/Platform.h" |
| |
| #if DAWN_COMPILER_IS(MSVC) |
| #include <intrin.h> |
| #endif |
| |
| namespace dawn { |
| |
| uint32_t ScanForward(uint32_t bits) { |
| DAWN_ASSERT(bits != 0); |
| #if DAWN_COMPILER_IS(MSVC) |
| // NOLINTNEXTLINE(runtime/int) |
| unsigned long firstBitIndex = 0ul; |
| unsigned char ret = _BitScanForward(&firstBitIndex, bits); |
| DAWN_ASSERT(ret != 0); |
| return firstBitIndex; |
| #else |
| return static_cast<uint32_t>(__builtin_ctz(bits)); |
| #endif |
| } |
| |
| uint32_t Log2(uint32_t value) { |
| DAWN_ASSERT(value != 0); |
| #if DAWN_COMPILER_IS(MSVC) |
| // NOLINTNEXTLINE(runtime/int) |
| unsigned long firstBitIndex = 0ul; |
| unsigned char ret = _BitScanReverse(&firstBitIndex, value); |
| DAWN_ASSERT(ret != 0); |
| return firstBitIndex; |
| #else |
| return 31 - static_cast<uint32_t>(__builtin_clz(value)); |
| #endif |
| } |
| |
| uint32_t Log2(uint64_t value) { |
| DAWN_ASSERT(value != 0); |
| #if DAWN_COMPILER_IS(MSVC) |
| #if DAWN_PLATFORM_IS(64_BIT) |
| // NOLINTNEXTLINE(runtime/int) |
| unsigned long firstBitIndex = 0ul; |
| unsigned char ret = _BitScanReverse64(&firstBitIndex, value); |
| DAWN_ASSERT(ret != 0); |
| return firstBitIndex; |
| #else // DAWN_PLATFORM_IS(64_BIT) |
| // NOLINTNEXTLINE(runtime/int) |
| unsigned long firstBitIndex = 0ul; |
| if (_BitScanReverse(&firstBitIndex, value >> 32)) { |
| return firstBitIndex + 32; |
| } |
| unsigned char ret = _BitScanReverse(&firstBitIndex, value & 0xFFFFFFFF); |
| DAWN_ASSERT(ret != 0); |
| return firstBitIndex; |
| #endif // DAWN_PLATFORM_IS(64_BIT) |
| #else // DAWN_COMPILER_IS(MSVC) |
| return 63 - static_cast<uint32_t>(__builtin_clzll(value)); |
| #endif // DAWN_COMPILER_IS(MSVC) |
| } |
| |
| uint64_t NextPowerOfTwo(uint64_t n) { |
| if (n <= 1) { |
| return 1; |
| } |
| |
| return 1ull << (Log2(n - 1) + 1); |
| } |
| |
| bool IsPowerOfTwo(uint64_t n) { |
| DAWN_ASSERT(n != 0); |
| return (n & (n - 1)) == 0; |
| } |
| |
| bool IsPtrAligned(const void* ptr, size_t alignment) { |
| DAWN_ASSERT(IsPowerOfTwo(alignment)); |
| DAWN_ASSERT(alignment != 0); |
| return (reinterpret_cast<size_t>(ptr) & (alignment - 1)) == 0; |
| } |
| |
| bool IsAligned(uint32_t value, size_t alignment) { |
| DAWN_ASSERT(alignment <= UINT32_MAX); |
| DAWN_ASSERT(IsPowerOfTwo(alignment)); |
| DAWN_ASSERT(alignment != 0); |
| uint32_t alignment32 = static_cast<uint32_t>(alignment); |
| return (value & (alignment32 - 1)) == 0; |
| } |
| |
| uint16_t Float32ToFloat16(float fp32) { |
| uint32_t fp32i = BitCast<uint32_t>(fp32); |
| uint32_t sign16 = (fp32i & 0x80000000) >> 16; |
| uint32_t mantissaAndExponent = fp32i & 0x7FFFFFFF; |
| |
| if (mantissaAndExponent > 0x7F800000) { // NaN |
| return 0x7FFF; |
| } else if (mantissaAndExponent > 0x47FFEFFF) { // Infinity |
| return static_cast<uint16_t>(sign16 | 0x7C00); |
| } else if (mantissaAndExponent < 0x38800000) { // Denormal |
| uint32_t mantissa = (mantissaAndExponent & 0x007FFFFF) | 0x00800000; |
| int32_t exponent = 113 - (mantissaAndExponent >> 23); |
| |
| if (exponent < 24) { |
| mantissaAndExponent = mantissa >> exponent; |
| } else { |
| mantissaAndExponent = 0; |
| } |
| |
| return static_cast<uint16_t>( |
| sign16 | (mantissaAndExponent + 0x00000FFF + ((mantissaAndExponent >> 13) & 1)) >> 13); |
| } else { |
| return static_cast<uint16_t>(sign16 | (mantissaAndExponent + 0xC8000000 + 0x00000FFF + |
| ((mantissaAndExponent >> 13) & 1)) >> |
| 13); |
| } |
| } |
| |
| float Float16ToFloat32(uint16_t fp16) { |
| uint32_t tmp = (fp16 & 0x7fff) << 13 | (fp16 & 0x8000) << 16; |
| float tmp2 = *reinterpret_cast<float*>(&tmp); |
| return pow(2, 127 - 15) * tmp2; |
| } |
| |
| bool IsFloat16NaN(uint16_t fp16) { |
| return (fp16 & 0x7FFF) > 0x7C00; |
| } |
| |
| // Based on the Khronos Data Format Specification 1.2 Section 13.3 sRGB transfer functions |
| float SRGBToLinear(float srgb) { |
| // sRGB is always used in unsigned normalized formats so clamp to [0.0, 1.0] |
| if (srgb <= 0.0f) { |
| return 0.0f; |
| } else if (srgb > 1.0f) { |
| return 1.0f; |
| } |
| |
| if (srgb < 0.04045f) { |
| return srgb / 12.92f; |
| } else { |
| return std::pow((srgb + 0.055f) / 1.055f, 2.4f); |
| } |
| } |
| |
| uint64_t RoundUp(uint64_t n, uint64_t m) { |
| DAWN_ASSERT(m > 0); |
| DAWN_ASSERT(n > 0); |
| DAWN_ASSERT(m <= std::numeric_limits<uint64_t>::max() - n); |
| return ((n + m - 1) / m) * m; |
| } |
| |
| } // namespace dawn |