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| author | Wilco Dijkstra <wilco.dijkstra@arm.com> | 2021-07-01 15:42:05 +0100 |
|---|---|---|
| committer | Wilco Dijkstra <wdijkstr@arm.com> | 2021-07-01 15:42:05 +0100 |
| commit | 6a34c928c2ac9fce926b1348d61dae34262e3f77 (patch) | |
| tree | bc0f927f7d6191b3338d59cc69a64291db993de4 /sysdeps/aarch64 | |
| parent | 252cad02d4c63540501b9b8c988cb91248563224 (diff) | |
| download | glibc-6a34c928c2ac9fce926b1348d61dae34262e3f77.zip glibc-6a34c928c2ac9fce926b1348d61dae34262e3f77.tar.gz glibc-6a34c928c2ac9fce926b1348d61dae34262e3f77.tar.bz2 | |
AArch64: Add hp-timing.h
Add hp-timing.h using the cntvct_el0 counter. Return timing in nanoseconds
so it is fully compatible with generic hp-timing. Don't set HP_TIMING_INLINE
in the dynamic linker since it adds unnecessary overheads and some ancient
kernels may not handle emulating cntcvt correctly. Currently cntvct_el0 is
only used for timing in the benchtests.
Reviewed-by: Szabolcs Nagy <szabolcs.nagy@arm.com>
Diffstat (limited to 'sysdeps/aarch64')
| -rw-r--r-- | sysdeps/aarch64/hp-timing.h | 47 |
1 files changed, 47 insertions, 0 deletions
diff --git a/sysdeps/aarch64/hp-timing.h b/sysdeps/aarch64/hp-timing.h new file mode 100644 index 0000000..f9822e7 --- /dev/null +++ b/sysdeps/aarch64/hp-timing.h @@ -0,0 +1,47 @@ +/* High precision, low overhead timing functions. AArch64 version. + Copyright (C) 2021 Free Software Foundation, Inc. + This file is part of the GNU C Library. + + The GNU C Library is free software; you can redistribute it and/or + modify it under the terms of the GNU Lesser General Public + License as published by the Free Software Foundation; either + version 2.1 of the License, or (at your option) any later version. + + The GNU C Library is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + Lesser General Public License for more details. + + You should have received a copy of the GNU Lesser General Public + License along with the GNU C Library; if not, see + <https://www.gnu.org/licenses/>. */ + +#ifndef _HP_TIMING_H +#define _HP_TIMING_H 1 + +#include <time.h> +#include <stdint.h> +#include <hp-timing-common.h> +#include <libc-symbols.h> + +/* Don't use inline timer in ld.so. */ +#if IS_IN(rtld) +# define HP_TIMING_INLINE (0) +#else +# define HP_TIMING_INLINE (1) +#endif + +typedef uint64_t hp_timing_t; + +#define HP_TIMING_NOW(var) \ + __asm__ __volatile__ ("isb; mrs %0, cntvct_el0" : "=r" (var)) + +/* Compute elapsed time in nanoseconds. */ +#undef HP_TIMING_DIFF +#define HP_TIMING_DIFF(Diff, Start, End) \ +({ hp_timing_t freq; \ + __asm__ __volatile__ ("mrs %0, cntfrq_el0" : "=r" (freq)); \ + (Diff) = ((End) - (Start)) * (UINT64_C(1000000000) / freq); \ +}) + +#endif /* hp-timing.h */ |