1
0
mirror of https://github.com/cc65/cc65.git synced 2024-11-17 09:07:32 +00:00
cc65/libsrc/atari/mul40.s
2014-01-04 20:33:24 +01:00

36 lines
671 B
ArmAsm

;
; Christian Groessler, June 2000
;
; mul40
; multiplies A by 40 and returns result in AX
; uses tmp4
.importzp tmp4
.export mul40,loc_tmp
.proc mul40
ldx #0
stx tmp4
sta loc_tmp
asl a
rol tmp4
asl a
rol tmp4 ; val * 4
adc loc_tmp
bcc L1
inc tmp4 ; val * 5
L1: asl a
rol tmp4 ; val * 10
asl a
rol tmp4
asl a
rol tmp4 ; val * 40
ldx tmp4
rts
.endproc
.bss
loc_tmp:.res 1