Runtime function improvements by Piotr Fusik

git-svn-id: svn://svn.cc65.org/cc65/trunk@2577 b7a2c559-68d2-44c3-8de9-860c34a00d81
2003-10-28 08:47:47 +00:00
parent 4319fd9cc7
commit 6d8cdae722
7 changed files with 86 additions and 90 deletions
--- a/libsrc/runtime/mulax7.s
+++ b/libsrc/runtime/mulax7.s
@@ -1,28 +1,29 @@
 ;
-; Ullrich von Bassewitz, 16.03.2002
+; Piotr Fusik, 24.10.2003
+; originally by Ullrich von Bassewitz
 ;
-; CC65 runtime: Multiply the primary register
+; CC65 runtime: Multiply the primary register by 7
 ;

-   	.export	    	mulax7
-	.importzp      	ptr1, tmp1
+	.export		mulax7
+	.importzp	ptr1

 .proc	mulax7

 	sta	ptr1
 	stx	ptr1+1
-	stx   	tmp1
-	asl   	a
-	rol   	tmp1	    		; * 2
 	asl	a
-	rol	tmp1			; * 4
+	rol	ptr1+1			; * 2
 	asl	a
-	rol	tmp1			; * 8
+	rol	ptr1+1			; * 4
+	asl	a
+	rol	ptr1+1			; * 8
 	sec
 	sbc	ptr1
 	pha
-	lda	tmp1
-	sbc	ptr1+1			; * (8 - 1)
+	txa
+	eor	#$ff
+	adc	ptr1+1			; * (8 - 1)
 	tax
 	pla
 	rts