LoongArch: Add ifunc support for strcpy, stpcpy{aligned, unaligned, lsx, lasx}

According to glibc strcpy and stpcpy microbenchmark test results(changed
to use generic_strcpy and generic_stpcpy instead of strlen + memcpy),
comparing with the generic version, this implementation could reduce the
runtime as following:

Name              Percent of rutime reduced
strcpy-aligned    8%-45%
strcpy-unaligned  8%-48%, comparing with the aligned version, unaligned
                  version takes less instructions to copy the tail of data
		  which length is less than 8. it also has better performance
		  in case src and dest cannot be both aligned with 8bytes
strcpy-lsx        20%-80%
strcpy-lasx       15%-86%
stpcpy-aligned    6%-43%
stpcpy-unaligned  8%-48%
stpcpy-lsx        10%-80%
stpcpy-lasx       10%-87%

1 files changed, 42 insertions, 0 deletions

diff --git a/sysdeps/loongarch/lp64/multiarch/stpcpy.c b/sysdeps/loongarch/lp64/multiarch/stpcpy.c
new file mode 100644
index 0000000000..d4860d7a47
--- /dev/null
+++ b/sysdeps/loongarch/lp64/multiarch/stpcpy.c
@@ -0,0 +1,42 @@
+/* Multiple versions of stpcpy.
+   All versions must be listed in ifunc-impl-list.c.
+   Copyright (C) 2017-2023 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/>.  */
+
+/* Define multiple versions only for the definition in libc.  */
+#if IS_IN (libc)
+# define stpcpy __redirect_stpcpy
+# define __stpcpy __redirect___stpcpy
+# define NO_MEMPCPY_STPCPY_REDIRECT
+# define __NO_STRING_INLINES
+# include <string.h>
+# undef stpcpy
+# undef __stpcpy
+
+# define SYMBOL_NAME stpcpy
+# include "ifunc-lasx.h"
+
+libc_ifunc_redirected (__redirect_stpcpy, __stpcpy, IFUNC_SELECTOR ());
+
+weak_alias (__stpcpy, stpcpy)
+# ifdef SHARED
+__hidden_ver1 (__stpcpy, __GI___stpcpy, __redirect___stpcpy)
+  __attribute__ ((visibility ("hidden"))) __attribute_copy__ (stpcpy);
+__hidden_ver1 (stpcpy, __GI_stpcpy, __redirect_stpcpy)
+  __attribute__ ((visibility ("hidden"))) __attribute_copy__ (stpcpy);
+# endif
+#endif