X-Git-Url: https://git.sur5r.net/?a=blobdiff_plain;f=libsrc%2Fcommon%2Fmemchr.s;h=1b60cbf73e5fee9db3dc394b3fb0be5477750a52;hb=934a78731fe1b7fc8d08814fa2321534c20fbc62;hp=59186ae453aeec31d289d3dc1d9a239d5edc679b;hpb=53dd513176425872128ef26031d00952ef7a0628;p=cc65

diff --git a/libsrc/common/memchr.s b/libsrc/common/memchr.s
index 59186ae45..1b60cbf73 100644
--- a/libsrc/common/memchr.s
+++ b/libsrc/common/memchr.s
@@ -1,57 +1,57 @@
 ;
-; Ullrich von Bassewitz, 09.06.1998
+; Ullrich von Bassewitz, 2003-05-05
 ;
-; void* memchr (const void* p, int c, size_t n);
+; void* __fastcall__ memchr (const void* p, int c, size_t n);
 ;
 
-	.export		_memchr
-	.import		popax, return0
-	.importzp	ptr1, ptr2, tmp1
-
-
-_memchr:
-       	sta	ptr2		; Save n
-	stx	ptr2+1
-	jsr	popax		; get c
-	sta	tmp1
-       	jsr	popax 	     	; get p
-       	sta	ptr1
-       	stx	ptr1+1
-
-       	ldy	#0
-	lda	tmp1		; get c
-	ldx	ptr2		; use X as low counter byte
-	beq	L3		; check high byte
-
-; Search for the char
-
-L1:	cmp	(ptr1),y
-       	beq    	L5  		; jump if found
-   	iny
-   	bne	L2
-   	inc     ptr1+1
-L2:	cpx	#0
-   	beq	L3
-   	dex
-   	jmp	L1
-L3:	ldx	ptr2+1		; Check high byte
-   	beq	L4  		; Jump if counter off
-   	dec	ptr2+1
-   	ldx	#$FF
-   	bne	L1		; branch always
-
-; Character not found, return zero
-
-L4:	jmp	return0
-
-; Character found, calculate pointer
-
-L5:  	ldx 	ptr1+1		; get high byte of pointer
-       	tya 			; low byte offset
-       	clc
-       	adc 	ptr1
-       	bcc 	L6
-       	inx
-L6:  	rts
+        .export         _memchr
+        .import         popax, return0
+        .importzp       ptr1, ptr2
 
 
+.proc   _memchr
+
+        eor     #$FF
+        sta     ptr2
+        txa
+        eor     #$FF
+        sta     ptr2+1          ; Save ones complement of n
+        jsr     popax           ; get c
+        pha
+        jsr     popax           ; get p
+        sta     ptr1
+        stx     ptr1+1
+
+        ldy     #$00
+        pla                     ; Get c
+        ldx     ptr2            ; Use X as low counter byte
+
+L1:     inx
+        beq     L3
+L2:     cmp     (ptr1),y
+        beq     found
+        iny
+        bne     L1
+        inc     ptr1+1
+        bne     L1              ; Branch always
+
+L3:     inc     ptr2+1          ; Bump counter high byte
+        bne     L2
+
+; Not found, return NULL
+
+notfound:
+        jmp     return0
+
+; Found, return pointer to char
+
+found:  ldx     ptr1+1          ; get high byte of pointer
+        tya                     ; low byte offset
+        clc
+        adc     ptr1
+        bcc     L9
+        inx
+L9:     rts
+
+.endproc
+