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 | |
13 | namespace LIBC_NAMESPACE { |
14 | |
15 | LLVM_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 | |