cc65/libsrc/runtime/mulax5.s

31 lines
488 B
ArmAsm

;
; Ullrich von Bassewitz, 04.10.2001
;
; CC65 runtime: Multiply the primary register by 5
;
; Don't touch the Y-register here, the optimizer relies on it!
.export mulax5
.importzp ptr1
.proc mulax5
sta ptr1
stx ptr1+1
asl a
rol ptr1+1
asl a
rol ptr1+1
clc
adc ptr1
pha
txa
adc ptr1+1
tax
pla
rts
.endproc