memchr: smaller i386 version

strrchr: smaller i386 version

    text           data     bss     dec     hex filename
-     33              0       0      33      21 libc/string/i386/memchr.o
+     28              0       0      28      1c libc/string/i386/memchr.o
-     31              0       0      31      1f libc/string/i386/strrchr.o
+     26              0       0      26      1a libc/string/i386/strrchr.o

1 files changed, 17 insertions, 12 deletions

diff --git a/libc/string/i386/strrchr.c b/libc/string/i386/strrchr.c
index ef378685b..3209b1d76 100644
--- a/libc/string/i386/strrchr.c
+++ b/libc/string/i386/strrchr.c
@@ -35,18 +35,23 @@
 /* Experimentally off - libc_hidden_proto(strrchr) */
 char *strrchr(const char *s, int c)
 {
-    int d0, d1;
-    register char * __res;
-    __asm__ __volatile__(
-	    "movb %%al,%%ah\n"
-	    "1:\tlodsb\n\t"
-	    "cmpb %%ah,%%al\n\t"
-	    "jne 2f\n\t"
-	    "leal -1(%%esi),%0\n"
-	    "2:\ttestb %%al,%%al\n\t"
-	    "jne 1b"
-	    :"=g" (__res), "=&S" (d0), "=&a" (d1) :"0" (0),"1" (s),"2" (c));
-    return __res;
+	char *retval;
+
+	__asm__ __volatile__(
+		"	movb	%%cl, %%ch\n"
+		"1:	movb	(%1), %%cl\n" /* load char */
+		"	cmpb	%%cl, %%ch\n" /* char == c? */
+		"	jne	2f\n"
+		"	movl	%1, %0\n"
+		"2:	incl	%1\n"
+		"	testb	%%cl, %%cl\n" /* char == NUL? */
+		"	jnz	1b\n"
+		/* "=c": use ecx, not ebx (-fpic uses it). */
+		: "=a" (retval), "=r" (s), "=c" (c)
+		: "0" (0), "1" (s), "2" (c)
+		/* : no clobbers */
+	);
+	return retval;
 }
 libc_hidden_def(strrchr)
 #ifdef __UCLIBC_SUSV3_LEGACY__