Avoid memset warning in one case.

git-mirror · Nov 10, 2009 · 6515a01 · 6515a01
1 parent 639d669
commit 6515a01
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Showing 2 changed files with 8 additions and 2 deletions.
diff --git a/ChangeLog b/ChangeLog
@@ -1,3 +1,8 @@
+2009-11-10  Ulrich Drepper  <drepper@redhat.com>
+
+	* string/bits/string3.h (memset): If the second parameter is constant
+	and zero there is likely no transposition.
+
 2009-11-04  Philippe De Muyter  <phdm@macqel.be>
 
 	* sysdeps/powerpc/fpu/e_sqrt.c: Fix spelling of (Newton-)Raphson.

diff --git a/string/bits/string3.h b/string/bits/string3.h
@@ -1,4 +1,4 @@
-/* Copyright (C) 2004, 2005, 2007 Free Software Foundation, Inc.
+/* Copyright (C) 2004, 2005, 2007, 2009 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
@@ -77,7 +77,8 @@ __NTH (mempcpy (void *__restrict __dest, __const void *__restrict __src,
 __extern_always_inline void *
 __NTH (memset (void *__dest, int __ch, size_t __len))
 {
-  if (__builtin_constant_p (__len) && __len == 0)
+  if (__builtin_constant_p (__len) && __len == 0
+      && (!__builtin_constant_p (__ch) || __ch != 0))
     {
       __warn_memset_zero_len ();
       return __dest;