xref: /plan9-contrib/sys/src/libc/386/memchr.s (revision 3e12c5d1bb89fc02707907988834ef147769ddaf)
1	TEXT	memchr(SB),$0
2
3	MOVL	n+8(FP), CX
4	CMPL	CX, $0
5	JEQ	none
6	MOVL	p+0(FP), DI
7	MOVBLZX	c+4(FP), AX
8	CLD
9/*
10 * SCASB is memchr instruction
11 */
12
13	REPN;	SCASB
14	JEQ	found
15
16none:
17	MOVL	$0, AX
18	RET
19
20found:
21	MOVL	DI, AX
22	SUBL	$1, AX
23	RET
24