mirror of
https://github.com/cc65/cc65.git
synced 2024-11-11 01:05:25 +00:00
66 lines
1.1 KiB
ArmAsm
66 lines
1.1 KiB
ArmAsm
;
|
|
; Ullrich von Bassewitz, 13.08.1998
|
|
;
|
|
; CC65 runtime: helper stuff for mod/div/mul with long signed ints
|
|
;
|
|
|
|
; When negating values, we will ignore the possibility here, that one of the
|
|
; values if $80000000, in which case the negate will fail.
|
|
|
|
.export poplsargs
|
|
.import getlop
|
|
.importzp sreg, tmp1, tmp2, ptr1, ptr3, ptr4
|
|
|
|
poplsargs:
|
|
jsr getlop ; Get the operands
|
|
|
|
; Remember the signs of the operands (that is, the high bytes) in tmp1 and
|
|
; tmp2. Make both operands positive.
|
|
|
|
lda sreg+1 ; Is the left operand negative?
|
|
sta tmp1 ; Remember the sign for later
|
|
bpl L1 ; Jump if not
|
|
|
|
clc ; Make it positive
|
|
lda ptr1
|
|
eor #$FF
|
|
adc #$01
|
|
sta ptr1
|
|
lda ptr1+1
|
|
eor #$FF
|
|
adc #$00
|
|
sta ptr1+1
|
|
lda sreg
|
|
eor #$FF
|
|
adc #$00
|
|
sta sreg
|
|
lda sreg+1
|
|
eor #$FF
|
|
adc #$00
|
|
sta sreg+1
|
|
|
|
L1: lda ptr4+1 ; Is the right operand nagative?
|
|
sta tmp2 ; Remember the sign for later
|
|
bpl L2 ; Jump if not
|
|
|
|
clc ; Make it positive
|
|
lda ptr3
|
|
eor #$FF
|
|
adc #$01
|
|
sta ptr3
|
|
lda ptr3+1
|
|
eor #$FF
|
|
adc #$00
|
|
sta ptr3+1
|
|
lda ptr4
|
|
eor #$FF
|
|
adc #$00
|
|
sta ptr4
|
|
lda ptr4+1
|
|
eor #$FF
|
|
adc #$00
|
|
sta ptr4+1
|
|
|
|
L2: rts
|
|
|