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/asreax4.s
+++ b/libsrc/runtime/asreax4.s
@@ -0,0 +1,23 @@
+;
+; Ullrich von Bassewitz, 25.07.2001
+;
+; CC65 runtime: Scale the 32 bit primary register by 16
+;
+
+       	.export		asreax4
+       	.importzp	sreg, tmp1
+
+asreax4:
+       	stx	tmp1
+       	ldx    	sreg+1
+	ldy	#4
+@L1:	cpx	#$80  		; Get bit 7 into carry
+       	ror	sreg+1
+       	ror	sreg
+       	ror	tmp1
+       	ror	a
+	dey
+	bne	@L1
+       	ldx	tmp1
+       	rts
+