1 //===-- Generic utilities for GPU timing ----------------------------------===// 2 // 3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. 4 // See https://llvm.org/LICENSE.txt for license information. 5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception 6 // 7 //===----------------------------------------------------------------------===// 8 9 #ifndef LLVM_LIBC_SRC_TIME_GPU_TIME_UTILS_H 10 #define LLVM_LIBC_SRC_TIME_GPU_TIME_UTILS_H 11 12 #include "hdr/time_macros.h" 13 #include "hdr/types/clock_t.h" 14 #include "src/__support/GPU/utils.h" 15 namespace LIBC_NAMESPACE { 16 17 #if defined(LIBC_TARGET_ARCH_IS_AMDGPU) 18 // AMDGPU does not have a single set frequency. Different architectures and 19 // cards can have different values. The actualy frequency needs to be read from 20 // the kernel driver and will be between 25 MHz and 100 MHz on most cards. All 21 // cards following the GFX9 ISAs use a 100 MHz clock so we will default to that. 22 constexpr uint64_t clock_freq = 100000000UL; 23 24 // We provide an externally visible symbol such that the runtime can set 25 // this to the correct value. 26 extern "C" { 27 [[gnu::visibility("protected")]] 28 extern gpu::Constant<uint64_t> __llvm_libc_clock_freq; 29 } 30 #define GPU_CLOCKS_PER_SEC static_cast<clock_t>(__llvm_libc_clock_freq) 31 32 #elif defined(LIBC_TARGET_ARCH_IS_NVPTX) 33 // NPVTX uses a single 1 GHz fixed frequency clock for all target architectures. 34 #define GPU_CLOCKS_PER_SEC static_cast<clock_t>(1000000000UL) 35 #else 36 #error "Unsupported target" 37 #endif 38 39 } // namespace LIBC_NAMESPACE 40 41 #endif // LLVM_LIBC_SRC_TIME_GPU_TIME_UTILS_H 42