mirror of git://sourceware.org/git/glibc.git
138 lines
4.1 KiB
C
138 lines
4.1 KiB
C
/* Measure memmove function combined throughput for different alignments.
|
|
Copyright (C) 2017-2018 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
|
|
<http://www.gnu.org/licenses/>. */
|
|
|
|
/* This microbenchmark measures the throughput of memmove for various sizes from
|
|
1 byte to 32MiB, doubling every iteration and then misaligning by 0-15
|
|
bytes. The copies are done from source to destination and then back and the
|
|
source walks forward across the array and the destination walks backward by
|
|
one byte each, thus measuring misaligned accesses as well. The idea is to
|
|
avoid caching effects by copying a different string and far enough from each
|
|
other, walking in different directions so that we can measure prefetcher
|
|
efficiency (software or hardware) more closely than with a loop copying the
|
|
same data over and over, which eventually only gives us L1 cache
|
|
performance. */
|
|
|
|
#ifndef MEMMOVE_RESULT
|
|
# define MEMMOVE_RESULT(dst, len) dst
|
|
# define START_SIZE 128
|
|
# define MIN_PAGE_SIZE (getpagesize () + 32 * 1024 * 1024)
|
|
# define TEST_MAIN
|
|
# define TEST_NAME "memmove"
|
|
# define TIMEOUT (20 * 60)
|
|
# include "bench-string.h"
|
|
|
|
IMPL (memmove, 1)
|
|
#endif
|
|
|
|
#include "json-lib.h"
|
|
|
|
typedef char *(*proto_t) (char *, const char *, size_t);
|
|
|
|
static void
|
|
do_one_test (json_ctx_t *json_ctx, impl_t *impl, char *dst, char *src,
|
|
size_t len)
|
|
{
|
|
size_t i = 0;
|
|
timing_t start, stop, cur;
|
|
|
|
char *dst_end = dst + MIN_PAGE_SIZE - len;
|
|
char *src_end = src + MIN_PAGE_SIZE - len;
|
|
|
|
TIMING_NOW (start);
|
|
/* Copy the entire buffer backwards, LEN at a time. */
|
|
for (; src_end >= src && dst <= dst_end; dst += len, src_end -= len, i++)
|
|
CALL (impl, dst, src_end, len);
|
|
TIMING_NOW (stop);
|
|
|
|
TIMING_DIFF (cur, start, stop);
|
|
|
|
/* Get time taken per function call. */
|
|
json_element_double (json_ctx, (double) cur / i);
|
|
}
|
|
|
|
static void
|
|
do_test (json_ctx_t *json_ctx, size_t len, bool overlap)
|
|
{
|
|
json_element_object_begin (json_ctx);
|
|
json_attr_uint (json_ctx, "length", (double) len);
|
|
json_array_begin (json_ctx, "timings");
|
|
|
|
if (overlap)
|
|
buf2 = buf1;
|
|
|
|
FOR_EACH_IMPL (impl, 0)
|
|
do_one_test (json_ctx, impl, (char *) buf2, (char *) buf1, len);
|
|
|
|
json_array_end (json_ctx);
|
|
json_element_object_end (json_ctx);
|
|
}
|
|
|
|
int
|
|
test_main (void)
|
|
{
|
|
json_ctx_t json_ctx;
|
|
|
|
test_init ();
|
|
|
|
json_init (&json_ctx, 0, stdout);
|
|
|
|
json_document_begin (&json_ctx);
|
|
json_attr_string (&json_ctx, "timing_type", TIMING_TYPE);
|
|
|
|
json_attr_object_begin (&json_ctx, "functions");
|
|
json_attr_object_begin (&json_ctx, "memmove");
|
|
json_attr_string (&json_ctx, "bench-variant", "walk");
|
|
|
|
json_array_begin (&json_ctx, "ifuncs");
|
|
FOR_EACH_IMPL (impl, 0)
|
|
json_element_string (&json_ctx, impl->name);
|
|
json_array_end (&json_ctx);
|
|
|
|
json_array_begin (&json_ctx, "results");
|
|
/* Non-overlapping buffers. */
|
|
for (size_t i = START_SIZE; i <= MIN_PAGE_SIZE; i <<= 1)
|
|
{
|
|
/* Test length alignments from 0-16 bytes. */
|
|
for (int j = 0; j < 8; j++)
|
|
{
|
|
do_test (&json_ctx, i + j, false);
|
|
do_test (&json_ctx, i + 16 - j, false);
|
|
}
|
|
}
|
|
|
|
/* Overlapping buffers. */
|
|
for (size_t i = START_SIZE; i <= MIN_PAGE_SIZE; i <<= 1)
|
|
{
|
|
/* Test length alignments from 0-16 bytes. */
|
|
for (int j = 0; j < 8; j++)
|
|
{
|
|
do_test (&json_ctx, i + j, true);
|
|
do_test (&json_ctx, i + 16 - j, true);
|
|
}
|
|
}
|
|
|
|
json_array_end (&json_ctx);
|
|
json_attr_object_end (&json_ctx);
|
|
json_attr_object_end (&json_ctx);
|
|
json_document_end (&json_ctx);
|
|
|
|
return ret;
|
|
}
|
|
|
|
#include <support/test-driver.c>
|