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;
; Ullrich von Bassewitz, 07.08.1998
; Christian Krueger, 11-Mar-2017, added 65SC02 optimization
; CC65 runtime: modulo operation for long signed ints
;
; When negating values, we will ignore the possibility here, that one of the
; values if $8000, in which case the negate will fail.
.export tosmod0ax, tosmodeax
.import poplsargs, udiv32, negeax
.importzp sreg, ptr1, ptr2, tmp1, tmp3, tmp4
.macpack cpu
tosmod0ax:
.if (.cpu .bitand ::CPU_ISET_65SC02)
stz sreg
stz sreg+1
.else
ldy #$00
sty sreg
sty sreg+1
.endif
tosmodeax:
jsr poplsargs ; Get arguments from stack, adjust sign
jsr udiv32 ; Do the division, remainder is in (ptr2:tmp3:tmp4)
; Load the result
lda ptr2
ldx ptr2+1
ldy tmp3
sty sreg
ldy tmp4
sty sreg+1
; Check the sign of the result. It is the sign of the left operand.
bit tmp1 ; Check sign of left operand
bpl Pos ; Jump if result is positive
; Result is negative
jmp negeax ; Negate result
; Result is positive
Pos: rts ; Done
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