glibc/sysdeps/x86/tst-hwcap-tunables.c
Noah Goldstein 5bcf6265f2 x86: Disable non-temporal memset on Skylake Server
The original commit enabling non-temporal memset on Skylake Server had
erroneous benchmarks (actually done on ICX).

Further benchmarks indicate non-temporal stores may in fact by a
regression on Skylake Server.

This commit may be over-cautious in some cases, but should avoid any
regressions for 2.40.

Tested using qemu on all x86_64 cpu arch supported by both qemu +
GLIBC.

Reviewed-by: DJ Delorie <dj@redhat.com>
Reviewed-by: H.J. Lu <hjl.tools@gmail.com>
2024-07-16 17:20:18 +08:00

149 lines
4.1 KiB
C

/* Tests for x86 GLIBC_TUNABLES=glibc.cpu.hwcaps filter.
Copyright (C) 2023-2024 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/>. */
#include <array_length.h>
#include <getopt.h>
#include <ifunc-impl-list.h>
#include <spawn.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <intprops.h>
#include <support/check.h>
#include <support/support.h>
#include <support/xunistd.h>
#include <support/capture_subprocess.h>
/* Nonzero if the program gets called via `exec'. */
#define CMDLINE_OPTIONS \
{ "restart", no_argument, &restart, 1 },
static int restart;
/* Disable everything. */
static const char *test_1[] =
{
"__memcpy_avx512_no_vzeroupper",
"__memcpy_avx512_unaligned",
"__memcpy_avx512_unaligned_erms",
"__memcpy_evex_unaligned",
"__memcpy_evex_unaligned_erms",
"__memcpy_avx_unaligned",
"__memcpy_avx_unaligned_erms",
"__memcpy_avx_unaligned_rtm",
"__memcpy_avx_unaligned_erms_rtm",
"__memcpy_ssse3",
};
static const struct test_t
{
const char *env;
const char *const *funcs;
size_t nfuncs;
} tests[] =
{
{
/* Disable everything. */
"-Prefer_ERMS,-Prefer_FSRM,-AVX,-AVX2,-AVX512F,-AVX512VL,"
"-SSE4_1,-SSE4_2,-SSSE3,-Fast_Unaligned_Load,-ERMS,"
"-AVX_Fast_Unaligned_Load,-Avoid_Non_Temporal_Memset",
test_1,
array_length (test_1)
},
{
/* Same as before, but with some empty suboptions. */
",-,-Prefer_ERMS,-Prefer_FSRM,-AVX,-AVX2,-AVX512F,-AVX512VL,"
"-SSE4_1,-SSE4_2,-SSSE3,-Fast_Unaligned_Load,,-,"
"-ERMS,-AVX_Fast_Unaligned_Load,-Avoid_Non_Temporal_Memset,-,",
test_1,
array_length (test_1)
}
};
/* Called on process re-execution. */
_Noreturn static void
handle_restart (int ntest)
{
struct libc_ifunc_impl impls[32];
int cnt = __libc_ifunc_impl_list ("memcpy", impls, array_length (impls));
if (cnt == 0)
_exit (EXIT_SUCCESS);
TEST_VERIFY_EXIT (cnt >= 1);
for (int i = 0; i < cnt; i++)
{
for (int f = 0; f < tests[ntest].nfuncs; f++)
{
if (strcmp (impls[i].name, tests[ntest].funcs[f]) == 0)
TEST_COMPARE (impls[i].usable, false);
}
}
_exit (EXIT_SUCCESS);
}
static int
do_test (int argc, char *argv[])
{
/* We must have either:
- One our fource parameters left if called initially:
+ path to ld.so optional
+ "--library-path" optional
+ the library path optional
+ the application name
+ the test to check */
TEST_VERIFY_EXIT (argc == 2 || argc == 5);
if (restart)
handle_restart (atoi (argv[1]));
char nteststr[INT_BUFSIZE_BOUND (int)];
char *spargv[10];
{
int i = 0;
for (; i < argc - 1; i++)
spargv[i] = argv[i + 1];
spargv[i++] = (char *) "--direct";
spargv[i++] = (char *) "--restart";
spargv[i++] = nteststr;
spargv[i] = NULL;
}
for (int i = 0; i < array_length (tests); i++)
{
snprintf (nteststr, sizeof nteststr, "%d", i);
printf ("[%d] Spawned test for %s\n", i, tests[i].env);
char *tunable = xasprintf ("glibc.cpu.hwcaps=%s", tests[i].env);
setenv ("GLIBC_TUNABLES", tunable, 1);
struct support_capture_subprocess result
= support_capture_subprogram (spargv[0], spargv, NULL);
support_capture_subprocess_check (&result, "tst-tunables", 0,
sc_allow_stderr);
support_capture_subprocess_free (&result);
free (tunable);
}
return 0;
}
#define TEST_FUNCTION_ARGV do_test
#include <support/test-driver.c>