about summary refs log tree commit diff
path: root/benchtests/bench-util.h
blob: 13927ff066bf7b0188735d1c038ffb257ce722fd (plain) (blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
/* Benchmark utility functions.
   Copyright (C) 2015-2023 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/>.  */

/* Prevent compiler to optimize away call.  */
#define DO_NOT_OPTIMIZE_OUT(value)		  \
  ({						  \
    __typeof (value) __v = (value);		  \
    asm volatile ("" : : "r,m" (__v) : "memory"); \
    __v;					  \
  })

#ifndef START_ITER
# define START_ITER (100000000)
#endif

/* bench_start reduces the random variations due to frequency scaling by
   executing a small loop with many memory accesses.  START_ITER controls
   the number of iterations.  */

void bench_start (void);