1
0
mirror of https://github.com/cc65/cc65.git synced 2024-12-23 04:30:10 +00:00
cc65/libsrc/runtime/lmod.s
cuz 82684d98fb Minor optimization suggested by Greg King
git-svn-id: svn://svn.cc65.org/cc65/trunk@1468 b7a2c559-68d2-44c3-8de9-860c34a00d81
2002-10-24 19:23:24 +00:00

40 lines
927 B
ArmAsm

;
; Ullrich von Bassewitz, 07.08.1998
;
; 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 tosmodeax
.import poplsargs, udiv32, negeax
.importzp sreg, ptr1, ptr2, tmp1, tmp3, tmp4
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