mirror of
https://github.com/cc65/cc65.git
synced 2024-06-01 13:41:34 +00:00
30 lines
974 B
ArmAsm
30 lines
974 B
ArmAsm
;
|
|
; Christian Krueger, 24-May-2018
|
|
;
|
|
; CC65 runtime: division for signed ints
|
|
;
|
|
|
|
; When negating values, we will ignore the possibility here, that one of the
|
|
; values is $8000, in which case the negate will fail.
|
|
|
|
.export tosdiva0, tosdivax
|
|
.import absvaludiv16, negax
|
|
.importzp sp, ptr1, tmp1
|
|
|
|
tosdiva0:
|
|
ldx #0
|
|
tosdivax:
|
|
pha ; Check if high-bytes indicate
|
|
txa ; different sign, so that we have to
|
|
ldy #1 ; negate the result after the operation.
|
|
eor (sp),y ; Eor with lhs high byte
|
|
sta tmp1 ; Save post negation indicator to tmp1
|
|
pla ; Back to entry accu
|
|
jsr absvaludiv16
|
|
ldx ptr1+1
|
|
lda ptr1
|
|
ldy tmp1 ; Fetch indicator
|
|
bmi negate
|
|
rts
|
|
negate: jmp negax
|