More shift routines

git-svn-id: svn://svn.cc65.org/cc65/trunk@820 b7a2c559-68d2-44c3-8de9-860c34a00d81
2001-07-25 21:36:01 +00:00
parent c2e45ea24d
commit d55c271c2a
8 changed files with 144 additions and 2 deletions
--- a/libsrc/runtime/asrax4.s
+++ b/libsrc/runtime/asrax4.s
@@ -0,0 +1,28 @@
+;
+; Ullrich von Bassewitz, 25.07.2001
+;
+; CC65 runtime: Scale the primary register by 16
+;
+
+      	.export		asrax4
+      	.importzp	tmp1
+
+asrax4:	stx	tmp1
+      	cpx	#$80  		; Put bit 7 into carry
+      	ror	tmp1
+      	ror	a
+	ldx	tmp1
+      	cpx	#$80
+      	ror	tmp1
+      	ror	a
+	ldx	tmp1
+      	cpx	#$80
+      	ror	tmp1
+      	ror	a
+      	ldx	tmp1
+      	cpx	#$80
+      	ror	tmp1
+      	ror	a
+      	ldx	tmp1
+      	rts
+