wcsmbs: optimize wcpcpy

This patch rewrites wcpcpy using wcslen and wmemcpy.  This is
similar to the optimizatio done on stpcpy by f559d8cf29.

Checked on x86_64-linux-gnu and string tests on a simulated
m68k-linux-gnu.

	* sysdeps/m68k/wcpcpy.c: Remove file.
	* wcsmbs/wcpcpy.c (__wcpcpy): Rewrite using wcslen and wmemcpy.

3 files changed, 8 insertions, 52 deletions

diff --git a/ChangeLog b/ChangeLog
index 8096175cc9..2e0b69d20d 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,8 @@
+2019-02-27  Adhemerval Zanella  <adhemerval.zanella@linaro.org>
+
+	* sysdeps/m68k/wcpcpy.c: Remove file.
+	* wcsmbs/wcpcpy.c (__wcpcpy): Rewrite using wcslen and wmemcpy.
+
 2019-02-26  Joseph Myers  <joseph@codesourcery.com>
 
 	* sysdeps/arm/sysdep.h (#if condition): Break lines before rather
diff --git a/sysdeps/m68k/wcpcpy.c b/sysdeps/m68k/wcpcpy.c
deleted file mode 100644
index a4bac08308..0000000000
--- a/sysdeps/m68k/wcpcpy.c
+++ /dev/null
@@ -1,36 +0,0 @@
-/* Copyright (C) 1996-2019 Free Software Foundation, Inc.
-   This file is part of the GNU C Library.
-   Contributed by Ulrich Drepper <drepper@gnu.ai.mit.edu>, 1996.
-
-   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/>.  */
-
-/* The generic version of this file assumes that __alignof__(wchar_t) ==
-   sizeof (wchar_t).  We therefore use this port-specific implementation
-   instead.  */
-#include <wchar.h>
-
-/* Copy SRC to DEST, returning the address of the terminating L'\0' in
-   DEST.  */
-wchar_t *
-__wcpcpy (wchar_t *dest, const wchar_t *src)
-{
-  do
-    ;
-  while ((*dest++ = *src++));
-
-  return dest - 1;
-}
-
-weak_alias (__wcpcpy, wcpcpy)
diff --git a/wcsmbs/wcpcpy.c b/wcsmbs/wcpcpy.c
index 01978e98f3..666fe150bc 100644
--- a/wcsmbs/wcpcpy.c
+++ b/wcsmbs/wcpcpy.c
@@ -18,31 +18,18 @@
 
 #include <wchar.h>
 
-#define __need_ptrdiff_t
-#include <stddef.h>
-
 #ifdef WCPCPY
 # define __wcpcpy WCPCPY
 #endif
+
 /* Copy SRC to DEST, returning the address of the terminating L'\0' in
    DEST.  */
 wchar_t *
 __wcpcpy (wchar_t *dest, const wchar_t *src)
 {
-  wchar_t *wcp = (wchar_t *) dest - 1;
-  wint_t c;
-  const ptrdiff_t off = src - dest + 1;
-
-  do
-    {
-      c = wcp[off];
-      *++wcp = c;
-    }
-  while (c != L'\0');
-
-  return wcp;
+  size_t len = __wcslen (src);
+  return __wmemcpy (dest, src, len + 1) + len;
 }
-
 #ifndef WCPCPY
 weak_alias (__wcpcpy, wcpcpy)
 #endif