glibc/benchtests/bench-memcpy.c
Noah Goldstein 5e6cce9b34 benchtests: Add additional cases to bench-memcpy.c and bench-memmove.c
This commit adds more benchmarks for the common memcpy/memmove
benchmarks. The most signifcant cases are the half page offsets. The
current versions leaves dst and src near page aligned which leads to
false 4k aliasing on x86_64. This can add noise due to false
dependencies from one run to the next. As well, this seems like more
of an edge case that common case so it shouldn't be the only thing

Signed-off-by: Noah Goldstein <goldstein.w.n@gmail.com>
Reviewed-by: H.J. Lu <hjl.tools@gmail.com>
2021-11-06 16:17:51 -05:00

216 lines
6.6 KiB
C

/* Measure memcpy functions.
Copyright (C) 2013-2021 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 MEMCPY_RESULT
# define MEMCPY_RESULT(dst, len) dst
# define MIN_PAGE_SIZE 131072
# define TEST_MAIN
# define TEST_NAME "memcpy"
# include "bench-string.h"
void *generic_memcpy (void *, const void *, size_t);
IMPL (memcpy, 1)
IMPL (generic_memcpy, 0)
#endif
# include "json-lib.h"
typedef void *(*proto_t) (void *, const void *, size_t);
static void
do_one_test (json_ctx_t *json_ctx, impl_t *impl, char *dst, const char *src,
size_t len)
{
size_t i, iters = INNER_LOOP_ITERS;
timing_t start, stop, cur;
for (i = 0; i < iters / 64; ++i)
{
CALL (impl, dst, src, len);
}
TIMING_NOW (start);
for (i = 0; i < iters; ++i)
{
CALL (impl, dst, src, len);
}
TIMING_NOW (stop);
TIMING_DIFF (cur, start, stop);
json_element_double (json_ctx, (double) cur / (double) iters);
}
static void
do_test (json_ctx_t *json_ctx, size_t align1, size_t align2, size_t len,
int both_ways)
{
size_t i, j;
char *s1, *s2;
size_t repeats;
align1 &= (getpagesize () - 1);
if (align1 + len >= page_size)
return;
align2 &= (getpagesize () - 1);
if (align2 + len >= page_size)
return;
s1 = (char *) (buf1 + align1);
s2 = (char *) (buf2 + align2);
for (repeats = both_ways ? 2 : 1; repeats; --repeats)
{
for (i = 0, j = 1; i < len; i++, j += 23)
s1[i] = j;
json_element_object_begin (json_ctx);
json_attr_uint (json_ctx, "length", (double) len);
json_attr_uint (json_ctx, "align1", (double) align1);
json_attr_uint (json_ctx, "align2", (double) align2);
json_attr_uint (json_ctx, "dst > src", (double) (s2 > s1));
json_array_begin (json_ctx, "timings");
FOR_EACH_IMPL (impl, 0)
do_one_test (json_ctx, impl, s2, s1, len);
json_array_end (json_ctx);
json_element_object_end (json_ctx);
s1 = (char *) (buf2 + align1);
s2 = (char *) (buf1 + align2);
}
}
int
test_main (void)
{
json_ctx_t json_ctx;
size_t i;
size_t half_page = getpagesize () / 2;
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, TEST_NAME);
json_attr_string (&json_ctx, "bench-variant", "default");
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");
for (i = 0; i < 18; ++i)
{
do_test (&json_ctx, 0, 0, 1 << i, 1);
do_test (&json_ctx, i, 0, 1 << i, 1);
do_test (&json_ctx, i + 32, 0, 1 << i, 1);
do_test (&json_ctx, 0, i, 1 << i, 1);
do_test (&json_ctx, 0, i + 32, 1 << i, 1);
do_test (&json_ctx, i, i, 1 << i, 1);
do_test (&json_ctx, i + 32, i + 32, 1 << i, 1);
do_test (&json_ctx, half_page, 0, 1 << i, 1);
do_test (&json_ctx, half_page + i, 0, 1 << i, 1);
do_test (&json_ctx, half_page, i, 1 << i, 1);
do_test (&json_ctx, half_page + i, i, 1 << i, 1);
}
for (i = 0; i < 32; ++i)
{
do_test (&json_ctx, 0, 0, i, 0);
do_test (&json_ctx, i, 0, i, 0);
do_test (&json_ctx, 0, i, i, 0);
do_test (&json_ctx, i, i, i, 0);
do_test (&json_ctx, half_page, 0, i, 0);
do_test (&json_ctx, half_page + i, 0, i, 0);
do_test (&json_ctx, half_page, i, i, 0);
do_test (&json_ctx, half_page + i, i, i, 0);
do_test (&json_ctx, getpagesize () - 1, 0, i, 0);
do_test (&json_ctx, 0, getpagesize () - 1, i, 0);
}
for (i = 3; i < 32; ++i)
{
if ((i & (i - 1)) == 0)
continue;
do_test (&json_ctx, 0, 0, 16 * i, 1);
do_test (&json_ctx, i, 0, 16 * i, 1);
do_test (&json_ctx, 0, i, 16 * i, 1);
do_test (&json_ctx, i, i, 16 * i, 1);
do_test (&json_ctx, half_page, 0, 16 * i, 1);
do_test (&json_ctx, half_page + i, 0, 16 * i, 1);
do_test (&json_ctx, half_page, i, 16 * i, 1);
do_test (&json_ctx, half_page + i, i, 16 * i, 1);
}
for (i = 32; i < 64; ++i)
{
do_test (&json_ctx, 0, 0, 32 * i, 1);
do_test (&json_ctx, i, 0, 32 * i, 1);
do_test (&json_ctx, 0, i, 32 * i, 1);
do_test (&json_ctx, i, i, 32 * i, 1);
do_test (&json_ctx, half_page, 0, 32 * i, 1);
do_test (&json_ctx, half_page + i, 0, 32 * i, 1);
do_test (&json_ctx, half_page, i, 32 * i, 1);
do_test (&json_ctx, half_page + i, i, 32 * i, 1);
}
do_test (&json_ctx, 0, 0, getpagesize (), 1);
for (i = 0; i <= 48; ++i)
{
do_test (&json_ctx, 0, 0, 2048 + 64 * i, 1);
do_test (&json_ctx, i, 0, 2048 + 64 * i, 1);
do_test (&json_ctx, i + 32, 0, 2048 + 64 * i, 1);
do_test (&json_ctx, 0, i, 2048 + 64 * i, 1);
do_test (&json_ctx, 0, i + 32, 2048 + 64 * i, 1);
do_test (&json_ctx, i, i, 2048 + 64 * i, 1);
do_test (&json_ctx, i + 32, i + 32, 2048 + 64 * i, 1);
do_test (&json_ctx, half_page, 0, 2048 + 64 * i, 1);
do_test (&json_ctx, half_page + i, 0, 2048 + 64 * i, 1);
do_test (&json_ctx, half_page, i, 2048 + 64 * i, 1);
do_test (&json_ctx, half_page + i, i, 2048 + 64 * i, 1);
do_test (&json_ctx, i, 1, 2048 + 64 * i, 1);
do_test (&json_ctx, 1, i, 2048 + 64 * i, 1);
do_test (&json_ctx, i + 32, 1, 2048 + 64 * i, 1);
do_test (&json_ctx, 1, i + 32, 2048 + 64 * i, 1);
do_test (&json_ctx, half_page + i, 1, 2048 + 64 * i, 1);
do_test (&json_ctx, half_page + 1, i, 2048 + 64 * i, 1);
}
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>
#define libc_hidden_builtin_def(X)
#undef MEMCPY
#define MEMCPY generic_memcpy
#include <string/memcpy.c>
#include <string/wordcopy.c>