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
 ;
@@ -12,32 +13,32 @@ tosicmp:
 	sta	sreg
 	stx	sreg+1		; Save ax
 
-	ldy    	#$01
-       	lda    	(sp),y 	       	; Get high byte
-	tax
-    	dey
+	ldy	#$00
 	lda	(sp),y		; Get low byte
-
-; Inline incsp2 for better performance
-
+	tax
 	inc	sp		; 5
 	bne	@L1		; 3
 	inc	sp+1		; (5)
-@L1:	inc	sp	   	; 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
+@L2:	sec
+	sbc	sreg+1		; Compare high byte
+	bne	@L4
+	cpx	sreg		; Compare low byte
 	beq	@L3
-       	bcs    	@L4
-       	lda	#$FF		; Set the N flag
+	adc	#$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

@@ -1,5 +1,6 @@
 ;
-; 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
 ;
@@ -15,7 +16,8 @@ toslcmp:
 
 	ldy	#$03
 	lda	(sp),y
-  	cmp	sreg+1
+	sec
+	sbc	sreg+1
 	bne	L4
 
 	dey
@@ -43,7 +45,10 @@ L2:  	rts
 L3:	lda	#$01		; Clear the N flag
 	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