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-exception
6//
7//===----------------------------------------------------------------------===//
8
9#include "time_utils.h"
10
11#include "src/time/clock.h"
12
13namespace LIBC_NAMESPACE {
14
15LLVM_LIBC_FUNCTION(clock_t, clock, ()) {
16 if (!GPU_CLOCKS_PER_SEC)
17 return clock_t(0);
18
19 uint64_t ticks = gpu::fixed_frequency_clock();
20
21 // We need to convert between the GPU's fixed frequency and whatever `time.h`
22 // declares it to be. This is done so that dividing the result of this
23 // function by 'CLOCKS_PER_SEC' yields the elapsed time.
24 if (GPU_CLOCKS_PER_SEC > CLOCKS_PER_SEC)
25 return clock_t(ticks / (GPU_CLOCKS_PER_SEC / CLOCKS_PER_SEC));
26 return clock_t(ticks * (CLOCKS_PER_SEC / GPU_CLOCKS_PER_SEC));
27}
28
29} // namespace LIBC_NAMESPACE
30

source code of libc/src/time/gpu/clock.cpp