xref: /aosp_15_r20/external/llvm-libc/src/time/gpu/clock_gettime.cpp (revision 71db0c75aadcf003ffe3238005f61d7618a3fead)
1*71db0c75SAndroid Build Coastguard Worker //===---------- GPU implementation of the POSIX clock_gettime function ----===//
2*71db0c75SAndroid Build Coastguard Worker //
3*71db0c75SAndroid Build Coastguard Worker // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4*71db0c75SAndroid Build Coastguard Worker // See https://llvm.org/LICENSE.txt for license information.
5*71db0c75SAndroid Build Coastguard Worker // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6*71db0c75SAndroid Build Coastguard Worker //
7*71db0c75SAndroid Build Coastguard Worker //===----------------------------------------------------------------------===//
8*71db0c75SAndroid Build Coastguard Worker 
9*71db0c75SAndroid Build Coastguard Worker #include "src/time/clock_gettime.h"
10*71db0c75SAndroid Build Coastguard Worker 
11*71db0c75SAndroid Build Coastguard Worker #include "src/__support/common.h"
12*71db0c75SAndroid Build Coastguard Worker #include "src/__support/macros/config.h"
13*71db0c75SAndroid Build Coastguard Worker #include "time_utils.h"
14*71db0c75SAndroid Build Coastguard Worker 
15*71db0c75SAndroid Build Coastguard Worker namespace LIBC_NAMESPACE_DECL {
16*71db0c75SAndroid Build Coastguard Worker 
17*71db0c75SAndroid Build Coastguard Worker constexpr uint64_t TICKS_PER_SEC = 1000000000UL;
18*71db0c75SAndroid Build Coastguard Worker 
19*71db0c75SAndroid Build Coastguard Worker LLVM_LIBC_FUNCTION(int, clock_gettime, (clockid_t clockid, timespec *ts)) {
20*71db0c75SAndroid Build Coastguard Worker   if (clockid != CLOCK_MONOTONIC || !ts)
21*71db0c75SAndroid Build Coastguard Worker     return -1;
22*71db0c75SAndroid Build Coastguard Worker 
23*71db0c75SAndroid Build Coastguard Worker   uint64_t ns_per_tick = TICKS_PER_SEC / GPU_CLOCKS_PER_SEC;
24*71db0c75SAndroid Build Coastguard Worker   uint64_t ticks = gpu::fixed_frequency_clock();
25*71db0c75SAndroid Build Coastguard Worker 
26*71db0c75SAndroid Build Coastguard Worker   ts->tv_nsec = (ticks * ns_per_tick) % TICKS_PER_SEC;
27*71db0c75SAndroid Build Coastguard Worker   ts->tv_sec = (ticks * ns_per_tick) / TICKS_PER_SEC;
28*71db0c75SAndroid Build Coastguard Worker 
29*71db0c75SAndroid Build Coastguard Worker   return 0;
30*71db0c75SAndroid Build Coastguard Worker }
31*71db0c75SAndroid Build Coastguard Worker 
32*71db0c75SAndroid Build Coastguard Worker } // namespace LIBC_NAMESPACE_DECL
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