blob: 1ec17272f1b9cda9a599ad3f6db38315ba8fa38b (
plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
|
/*
* 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>
ENTRY(memchr)
RETGUARD_SETUP(memchr, r11)
movb %sil,%al /* set character to search for */
movq %rdx,%rcx /* set length of search */
testq %rcx,%rcx /* test for len == 0 */
jz L1
repne /* search! */
scasb
jne L1 /* scan failed, return null */
leaq -1(%rdi),%rax /* adjust result of scan */
jmp L2
L1: xorq %rax,%rax
L2: RETGUARD_CHECK(memchr, r11)
ret
|
