1 /* High precision, low overhead timing functions. AArch64 version. 2 Copyright (C) 2021-2022 Free Software Foundation, Inc. 3 This file is part of the GNU C Library. 4 5 The GNU C Library is free software; you can redistribute it and/or 6 modify it under the terms of the GNU Lesser General Public 7 License as published by the Free Software Foundation; either 8 version 2.1 of the License, or (at your option) any later version. 9 10 The GNU C Library is distributed in the hope that it will be useful, 11 but WITHOUT ANY WARRANTY; without even the implied warranty of 12 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU 13 Lesser General Public License for more details. 14 15 You should have received a copy of the GNU Lesser General Public 16 License along with the GNU C Library; if not, see 17 <https://www.gnu.org/licenses/>. */ 18 19 #ifndef _HP_TIMING_H 20 #define _HP_TIMING_H 1 21 22 #include <time.h> 23 #include <stdint.h> 24 #include <hp-timing-common.h> 25 #include <libc-symbols.h> 26 27 /* Don't use inline timer in ld.so. */ 28 #if IS_IN(rtld) 29 # define HP_TIMING_INLINE (0) 30 #else 31 # define HP_TIMING_INLINE (1) 32 #endif 33 34 typedef uint64_t hp_timing_t; 35 36 #define HP_TIMING_NOW(var) \ 37 __asm__ __volatile__ ("isb; mrs %0, cntvct_el0" : "=r" (var)) 38 39 /* Compute elapsed time in nanoseconds. */ 40 #undef HP_TIMING_DIFF 41 #define HP_TIMING_DIFF(Diff, Start, End) \ 42 ({ hp_timing_t freq; \ 43 __asm__ __volatile__ ("mrs %0, cntfrq_el0" : "=r" (freq)); \ 44 (Diff) = ((End) - (Start)) * (UINT64_C(1000000000) / freq); \ 45 }) 46 47 #endif /* hp-timing.h */ 48