1 //===---------- GPU implementation of the POSIX clock_gettime 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 "src/time/clock_gettime.h" 10 11 #include "src/__support/common.h" 12 #include "src/__support/macros/config.h" 13 #include "time_utils.h" 14 15 namespace LIBC_NAMESPACE_DECL { 16 17 constexpr uint64_t TICKS_PER_SEC = 1000000000UL; 18 19 LLVM_LIBC_FUNCTION(int, clock_gettime, (clockid_t clockid, timespec *ts)) { 20 if (clockid != CLOCK_MONOTONIC || !ts) 21 return -1; 22 23 uint64_t ns_per_tick = TICKS_PER_SEC / GPU_CLOCKS_PER_SEC; 24 uint64_t ticks = gpu::fixed_frequency_clock(); 25 26 ts->tv_nsec = (ticks * ns_per_tick) % TICKS_PER_SEC; 27 ts->tv_sec = (ticks * ns_per_tick) / TICKS_PER_SEC; 28 29 return 0; 30 } 31 32 } // namespace LIBC_NAMESPACE_DECL 33