glibc/sysdeps/generic/hp-timing-common.h

60 lines
2.4 KiB
C

/* High precision, low overhead timing functions. Generic version.
Copyright (C) 1998-2023 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/>. */
/* In case a platform supports timers in the hardware the following macros
and types must be defined:
- HP_TIMING_INLINE: this macro is non-zero if the functionality is not
implemented using function calls but instead uses some inlined code
which might simply consist of a few assembler instructions. We have to
know this since we might want to use the macros here in places where we
cannot make function calls.
- hp_timing_t: This is the type for variables used to store the time
values. This type must be integral.
- HP_TIMING_NOW: place timestamp for current time in variable given as
parameter.
*/
/* The target supports hp-timing. Share the common infrastructure. */
#include <string.h>
#include <sys/param.h>
#include <_itoa.h>
/* Compute the difference between START and END, storing into DIFF. */
#define HP_TIMING_DIFF(Diff, Start, End) ((Diff) = (End) - (Start))
/* Accumulate ADD into SUM. No attempt is made to be thread-safe. */
#define HP_TIMING_ACCUM_NT(Sum, Diff) ((Sum) += (Diff))
#define HP_TIMING_PRINT_SIZE (3 * sizeof (hp_timing_t) + 1)
/* Write a decimal representation of the timing value into the given string. */
#define HP_TIMING_PRINT(Dest, Len, Val) \
do { \
char __buf[HP_TIMING_PRINT_SIZE]; \
char *__dest = (Dest); \
size_t __len = (Len); \
char *__cp = _itoa ((Val), __buf + sizeof (__buf), 10, 0); \
size_t __cp_len = MIN (__buf + sizeof (__buf) - __cp, __len); \
memcpy (__dest, __cp, __cp_len); \
__dest[__cp_len - 1] = '\0'; \
} while (0)