[src/trunk]: src/common/lib/libc/arch/i386/string/small Look for the characte...

[khorben <khorben%NetBSD.org@localhost>]

details:   https://anonhg.NetBSD.org/src/rev/09fe207fb11c
branches:  trunk
changeset: 332469:09fe207fb11c
user:      khorben <khorben%NetBSD.org@localhost>
date:      Mon Sep 22 20:31:56 2014 +0000

description:
Look for the character to locate before checking for the NUL character

As documented in PR port-i386/49208, this fixes strchr(s, '\0'), as used by
the FAT first-stage bootloader on x86 (bootxx_msdos).
strchr(s, '\0') is otherwise equivalent to strlen(string), which would
probably look nicer in the original file, dosfs.c from libsa.

Confirmed working in qemu and on real hardware.
ok joerg@

XXX pull-up to netbsd-6 and netbsd-7

diffstat:

 common/lib/libc/arch/i386/string/small/strchr.S |  8 ++++----
 1 files changed, 4 insertions(+), 4 deletions(-)

diffs (31 lines):

diff -r 257c2d84de7e -r 09fe207fb11c common/lib/libc/arch/i386/string/small/strchr.S
--- a/common/lib/libc/arch/i386/string/small/strchr.S   Mon Sep 22 19:01:02 2014 +0000
+++ b/common/lib/libc/arch/i386/string/small/strchr.S   Mon Sep 22 20:31:56 2014 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: strchr.S,v 1.2 2014/03/22 19:38:46 jakllsch Exp $      */
+/*     $NetBSD: strchr.S,v 1.3 2014/09/22 20:31:56 khorben Exp $       */
 /*-
  * Copyright (c) 2011 The NetBSD Foundation, Inc.
  * All rights reserved.
@@ -29,7 +29,7 @@
  */
 
 #include <machine/asm.h>
-       RCSID("$NetBSD: strchr.S,v 1.2 2014/03/22 19:38:46 jakllsch Exp $")
+       RCSID("$NetBSD: strchr.S,v 1.3 2014/09/22 20:31:56 khorben Exp $")
 
 ENTRY(strchr)
        popl    %edx            /* Return address */
@@ -39,10 +39,10 @@
        pushl   %eax
        pushl   %edx
 1:
+       cmpb    %cl, 0(%eax)
+       je 3f
        cmpb    $0, 0(%eax)
        je 2f
-       cmpb    %cl, 0(%eax)
-       je 3f
        incl    %eax
        jmp 1b
 2: