From: Adhemerval Zanella <adhemerval.zanella@linaro.org>
Date: Tue, 31 Jan 2023 19:28:42 +0000 (-0300)
Subject: string: Improve generic strcpy
X-Git-Tag: glibc-2.38~628
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=3709ed904770b440d68385f3da259008cdf642a6;p=thirdparty%2Fglibc.git

string: Improve generic strcpy

Now that stpcpy is vectorized based on op_t, it should be better to
call it instead of strlen plus memcpy.

Checked on x86_64-linux-gnu, i686-linux-gnu, powerpc64-linux-gnu,
and powerpc-linux-gnu by removing the arch-specific assembly
implementation and disabling multi-arch (it covers both LE and BE
for 64 and 32 bits).

Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Reviewed-by: Noah Goldstein <goldstein.w.n@gmail.com>
---

diff --git a/string/strcpy.c b/string/strcpy.c
index 0345c71d15a..d945d8fdf06 100644
--- a/string/strcpy.c
+++ b/string/strcpy.c
@@ -19,6 +19,9 @@
 #include <string.h>
 
 #undef strcpy
+/* Disable internal stpcpy optimization, otherwise the __stpcpy might it
+   generate a strcpy call.  */
+#undef __stpcpy
 
 #ifndef STRCPY
 # define STRCPY strcpy
@@ -28,6 +31,7 @@
 char *
 STRCPY (char *dest, const char *src)
 {
-  return memcpy (dest, src, strlen (src) + 1);
+  __stpcpy (dest, src);
+  return dest;
 }
 libc_hidden_builtin_def (strcpy)