32 lines · cpp
1//===-- GPU implementation of the clock function --------------------------===//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-exception6//7//===----------------------------------------------------------------------===//8 9#include "src/time/clock.h"10 11#include "src/__support/common.h"12#include "src/__support/macros/config.h"13#include "src/__support/time/gpu/time_utils.h"14 15namespace LIBC_NAMESPACE_DECL {16 17LLVM_LIBC_FUNCTION(clock_t, clock, ()) {18 if (!GPU_CLOCKS_PER_SEC)19 return clock_t(0);20 21 uint64_t ticks = gpu::fixed_frequency_clock();22 23 // We need to convert between the GPU's fixed frequency and whatever `time.h`24 // declares it to be. This is done so that dividing the result of this25 // function by 'CLOCKS_PER_SEC' yields the elapsed time.26 if (GPU_CLOCKS_PER_SEC > CLOCKS_PER_SEC)27 return clock_t(ticks / (GPU_CLOCKS_PER_SEC / CLOCKS_PER_SEC));28 return clock_t(ticks * (CLOCKS_PER_SEC / GPU_CLOCKS_PER_SEC));29}30 31} // namespace LIBC_NAMESPACE_DECL32