x86: Add support to build strcmp/strlen/strchr with explicit ISA level

[thirdparty/glibc.git] / sysdeps / x86_64 / strncmp.S

diff --git a/sysdeps/x86_64/strncmp.S b/sysdeps/x86_64/strncmp.S
index 13d9e82ee2bbacbee9c31d675a4ae9ebb1a685e7..afb251d9fe0e171206320ac7b39bd6813656c24c 100644 (file)
--- a/sysdeps/x86_64/strncmp.S
+++ b/sysdeps/x86_64/strncmp.S
@@ -1,4 +1,31 @@
+/* strncmp dispatch for RTLD and non-multiarch build
+   Copyright (C) 1999-2022 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/>.  */
+
 /* Symbol = strncmp.  */
 
-#include "multiarch/strncmp-sse2.S"
+#define DEFAULT_IMPL_V1        "multiarch/strncmp-sse2.S"
+/* This may cause regressions on some processors that heavily prefer
+   aligned loads or have slow a implementation of the `pcmpstri`
+   instruction.  */
+#define DEFAULT_IMPL_V2        "multiarch/strncmp-sse4_2.S"
+#define DEFAULT_IMPL_V3        "multiarch/strncmp-avx2.S"
+#define DEFAULT_IMPL_V4        "multiarch/strncmp-evex.S"
+
+#include "isa-default-impl.h"
+
 libc_hidden_builtin_def (strncmp)