mirror of
https://github.com/cc65/cc65.git
synced 2024-12-23 19:29:37 +00:00
36 lines
1006 B
ArmAsm
36 lines
1006 B
ArmAsm
;
|
|
; Ullrich von Bassewitz, 26.10.2000
|
|
;
|
|
; CC65 runtime: Push value in a/x onto the stack
|
|
;
|
|
|
|
.export push0, pusha0, pushax
|
|
.importzp sp
|
|
|
|
push0: lda #0
|
|
pusha0: ldx #0
|
|
|
|
; This function is used *a lot*, so don't call any subroutines here.
|
|
; Beware: The value in ax must not be changed by this function!
|
|
; Beware^2: The optimizer knows about the value of Y after the function
|
|
; returns!
|
|
|
|
.proc pushax
|
|
|
|
pha ; (3)
|
|
lda sp ; (6)
|
|
sec ; (8)
|
|
sbc #2 ; (10)
|
|
sta sp ; (13)
|
|
bcs @L1 ; (17)
|
|
dec sp+1 ; (+5)
|
|
@L1: ldy #1 ; (19)
|
|
txa ; (21)
|
|
sta (sp),y ; (27)
|
|
pla ; (31)
|
|
dey ; (33)
|
|
sta (sp),y ; (38)
|
|
rts ; (44)
|
|
|
|
.endproc
|