| /* | |
| * Copyright (c) 2020-2022 NVIDIA CORPORATION & AFFILIATES. All rights reserved. | |
| * | |
| * NVIDIA CORPORATION, its affiliates and licensors retain all intellectual | |
| * property and proprietary rights in and to this material, related | |
| * documentation and any modifications thereto. Any use, reproduction, | |
| * disclosure or distribution of this material and related documentation | |
| * without an express license agreement from NVIDIA CORPORATION or | |
| * its affiliates is strictly prohibited. | |
| */ | |
| //------------------------------------------------------------------------ | |
| // Block and grid size calculators for kernel launches. | |
| dim3 getLaunchBlockSize(int maxWidth, int maxHeight, dim3 dims) | |
| { | |
| int maxThreads = maxWidth * maxHeight; | |
| if (maxThreads <= 1 || (dims.x * dims.y) <= 1) | |
| return dim3(1, 1, 1); // Degenerate. | |
| // Start from max size. | |
| int bw = maxWidth; | |
| int bh = maxHeight; | |
| // Optimizations for weirdly sized buffers. | |
| if (dims.x < bw) | |
| { | |
| // Decrease block width to smallest power of two that covers the buffer width. | |
| while ((bw >> 1) >= dims.x) | |
| bw >>= 1; | |
| // Maximize height. | |
| bh = maxThreads / bw; | |
| if (bh > dims.y) | |
| bh = dims.y; | |
| } | |
| else if (dims.y < bh) | |
| { | |
| // Halve height and double width until fits completely inside buffer vertically. | |
| while (bh > dims.y) | |
| { | |
| bh >>= 1; | |
| if (bw < dims.x) | |
| bw <<= 1; | |
| } | |
| } | |
| // Done. | |
| return dim3(bw, bh, 1); | |
| } | |
| // returns the size of a block that can be reduced using horizontal SIMD operations (e.g. __shfl_xor_sync) | |
| dim3 getWarpSize(dim3 blockSize) | |
| { | |
| return dim3( | |
| std::min(blockSize.x, 32u), | |
| std::min(std::max(32u / blockSize.x, 1u), std::min(32u, blockSize.y)), | |
| std::min(std::max(32u / (blockSize.x * blockSize.y), 1u), std::min(32u, blockSize.z)) | |
| ); | |
| } | |
| dim3 getLaunchGridSize(dim3 blockSize, dim3 dims) | |
| { | |
| dim3 gridSize; | |
| gridSize.x = (dims.x - 1) / blockSize.x + 1; | |
| gridSize.y = (dims.y - 1) / blockSize.y + 1; | |
| gridSize.z = (dims.z - 1) / blockSize.z + 1; | |
| return gridSize; | |
| } | |
| //------------------------------------------------------------------------ | |