Initial revision

lib/i86/string/memchr.s

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+!	memchr()					Author: Kees J. Bot
+!								27 Jan 1994
+.sect .text; .sect .rom; .sect .data; .sect .bss
+
+! void *memchr(const void *s, int c, size_t n)
+!	Look for a character in a chunk of memory.
+!
+.sect .text
+.define _memchr
+_memchr:
+	push	bp
+	mov	bp, sp
+	push	di
+	mov	di, 4(bp)	! di = string
+	movb	al, 6(bp)	! The character to look for
+	mov	cx, 8(bp)	! Length
+	cmpb	cl, #1		! 'Z' bit must be clear if cx = 0
+	cld
+  repne	scasb
+	jne	failure
+	lea	ax, -1(di)	! Found
+	pop	di
+	pop	bp
+	ret
+failure:xor	ax, ax
+	pop	di
+	pop	bp
+	ret