cc65/libsrc/runtime/shelp.s

30 lines
824 B
ArmAsm

;
; Ullrich von Bassewitz, 07.08.1998
;
; CC65 runtime: helper stuff for mod/div with 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 popsargsudiv16
.import negax, popax, udiv16
.importzp tmp1, tmp2, ptr1, ptr4
popsargsudiv16:
stx tmp2 ; Remember sign
cpx #0
bpl L1
jsr negax ; Negate accumulator
L1: sta ptr4
stx ptr4+1 ; Save right operand
jsr popax
stx tmp1 ; Remember sign
cpx #0
bpl L2
jsr negax
L2: sta ptr1
stx ptr1+1
jmp udiv16 ; Call the division