* sysdeps/i386/i686/memset.S: Fix treatment of unaligned pointer.

	Reported by John Zulauf <john.zulauf@amd.com>.

diff --git a/ChangeLog b/ChangeLog
index f3a99ef..e9562d4 100644 (file)
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,8 @@
+2006-02-21  Roland McGrath  <roland@redhat.com>
+
+       * sysdeps/i386/i686/memset.S: Fix treatment of unaligned pointer.
+       Reported by John Zulauf <john.zulauf@amd.com>.
+
 2004-11-23  Richard Sandiford  <rsandifo@redhat.com>
 
        * configure.in (libc_cv_gcc_dwarf2_unwind_info): Delete.

diff --git a/sysdeps/i386/i686/memset.S b/sysdeps/i386/i686/memset.S
index 5ea50ef..dfa1aa7 100644 (file)
--- a/sysdeps/i386/i686/memset.S
+++ b/sysdeps/i386/i686/memset.S
@@ -1,6 +1,6 @@
 /* memset/bzero -- set memory area to CH/0
    Highly optimized version for ix86, x>=6.
-   Copyright (C) 1999, 2000, 2003, 2005 Free Software Foundation, Inc.
+   Copyright (C) 1999,2000,2003,2005,2006 Free Software Foundation, Inc.
    This file is part of the GNU C Library.
    Contributed by Ulrich Drepper <drepper@cygnus.com>, 1999.
 
@@ -64,17 +64,17 @@ ENTRY (BP_SYM (memset))
        movl    %edx, %edi
        cfi_rel_offset (edi, 0)
        andl    $3, %edx
-       jz      2f
-       jnp     3f
-       stosb
+       jz      2f      /* aligned */
+       jp      3f      /* misaligned at 3, store just one byte below */
+       stosb           /* misaligned at 1 or 2, store two bytes */
        decl    %ecx
        jz      1f
 3:     stosb
        decl    %ecx
        jz      1f
-       xorl    $3, %edx
-       jz      2f
-       stosb
+       xorl    $1, %edx
+       jnz     2f      /* was misaligned at 2 or 3, now aligned */
+       stosb           /* was misaligned at 1, store third byte */
        decl    %ecx
 2:     movl    %ecx, %edx
        shrl    $2, %ecx