Fixed wrong compares (new code by Piotr Fusik)

git-svn-id: svn://svn.cc65.org/cc65/trunk@1243 b7a2c559-68d2-44c3-8de9-860c34a00d81

libsrc/runtime/icmp.s

@@ -1,5 +1,6 @@
 ;
-; Ullrich von Bassewitz, 10.12.1998
+; Piotr Fusik, 15.04.2002
+; originally by Ullrich von Bassewitz
 ;
 ; Integer compare function - used by the compare operators
 ;
@@ -9,35 +10,35 @@
 
 
 tosicmp:
-  	sta	sreg
-	stx	sreg+1	   	; Save ax
+	sta	sreg
+	stx	sreg+1		; Save ax
 
-	ldy    	#$01
-       	lda    	(sp),y 	       	; Get high byte
+	ldy	#$00
+	lda	(sp),y		; Get low byte
 	tax
-    	dey
-    	lda	(sp),y	   	; Get low byte
-
-; Inline incsp2 for better performance
-
-    	inc	sp	   	; 5
-       	bne	@L1	   	; 3
-    	inc	sp+1	   	; (5)
-@L1:	inc	sp	   	; 5
-    	bne	@L2	   	; 3
-    	inc	sp+1	   	; (5)
+	inc	sp		; 5
+	bne	@L1		; 3
+	inc	sp+1		; (5)
+@L1:
+	lda	(sp),y		; Get high byte
+	inc	sp		; 5
+	bne	@L2		; 3
+	inc	sp+1		; (5)
 
 ; Do the compare.
 
-@L2:	cpx	sreg+1	   	; Compare high byte
-    	bne    	@L3
-    	cmp	sreg  	   	; Compare low byte
-       	beq	@L3
-       	bcs    	@L4
-       	lda	#$FF		; Set the N flag
-@L3: 	rts
+@L2:	sec
+	sbc	sreg+1		; Compare high byte
+	bne	@L4
+	cpx	sreg		; Compare low byte
+	beq	@L3
+	adc	#$FF		; If the C flag is set then clear the N flag
+	ora	#$01		; else set the N flag
+@L3:	rts
 
-@L4:   	lda    	#$01		; Clear the N flag
+@L4:	bvc	@L3
+	eor	#$FF		; Fix the N flag if overflow
+	ora	#$01		; Clear the Z flag
 	rts
 
 

libsrc/runtime/lcmp.s

@@ -1,51 +1,56 @@
 ;
-; Ullrich von Bassewitz, 10.12.1998
+; Piotr Fusik, 15.04.2002
+; originally by Ullrich von Bassewitz
 ;
 ; Long int compare function - used by the compare operators
 ;
 
- 	.export		toslcmp
- 	.import		incsp4
- 	.importzp	sp, sreg, ptr1
+	.export		toslcmp
+	.import		incsp4
+	.importzp	sp, sreg, ptr1
 
 
 toslcmp:
-  	sta    	ptr1
-  	stx	ptr1+1 	  	; EAX now in sreg:ptr1
+	sta	ptr1
+	stx	ptr1+1		; EAX now in sreg:ptr1
 
-  	ldy    	#$03
-       	lda    	(sp),y
-  	cmp	sreg+1
-  	bne	L4
+	ldy	#$03
+	lda	(sp),y
+	sec
+	sbc	sreg+1
+	bne	L4
 
-  	dey
-  	lda	(sp),y
-  	cmp	sreg
-  	bne	L1
+	dey
+	lda	(sp),y
+	cmp	sreg
+	bne	L1
 
-  	dey
-  	lda	(sp),y
-  	cmp	ptr1+1
-  	bne	L1
+	dey
+	lda	(sp),y
+	cmp	ptr1+1
+	bne	L1
 
-  	dey
-  	lda	(sp),y
-  	cmp	ptr1
+	dey
+	lda	(sp),y
+	cmp	ptr1
 
-L1:	php	      		; Save flags
-   	jsr	incsp4		; Drop TOS
-   	plp	  		; Restore the flags
-   	beq	L2
-   	bcs	L3
-   	lda	#$FF		; Set the N flag
-L2:  	rts
+L1:	php			; Save flags
+	jsr	incsp4		; Drop TOS
+	plp			; Restore the flags
+	beq	L2
+	bcs	L3
+	lda	#$FF		; Set the N flag
+L2:	rts
 
 L3:	lda	#$01		; Clear the N flag
-  	rts
+	rts
 
-L4:	php	  		; Save flags
+L4:	bvc	L5
+	eor	#$FF		; Fix the N flag if overflow
+	ora	#$01		; Clear the Z flag
+L5:	php			; Save flags
 	jsr	incsp4		; Drop TOS
-	plp	  		; Restore flags
-  	rts
+	plp			; Restore flags
+	rts