NetBSD/sys/lib/libkern/arch/x86_64/index.S

30 lines
502 B
ArmAsm

/*
* Written by J.T. Conklin <jtc@netbsd.org>.
* Public domain.
* Adapted for NetBSD/x86_64 by Frank van der Linden <fvdl@wasabisystems.com>
*/
#include <machine/asm.h>
#if defined(LIBC_SCCS)
RCSID("$NetBSD: index.S,v 1.1 2001/06/19 00:22:46 fvdl Exp $")
#endif
#ifdef STRCHR
ENTRY(strchr)
#else
ENTRY(index)
#endif
movq %rdi,%rax
movb %sil,%cl
L1:
movb (%rax),%dl
cmpb %dl,%cl /* found char? */
je L2
incq %rax
testb %dl,%dl /* null terminator? */
jnz L1
xorq %rax,%rax
L2:
ret