mirror of
https://github.com/cc65/cc65.git
synced 2024-12-24 11:31:31 +00:00
b4163d0e4e
git-svn-id: svn://svn.cc65.org/cc65/trunk@484 b7a2c559-68d2-44c3-8de9-860c34a00d81
48 lines
931 B
ArmAsm
48 lines
931 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!
|
|
|
|
pushax: ldy sp
|
|
beq @L1
|
|
dey
|
|
beq @L2
|
|
dey
|
|
@L0: sty sp
|
|
.ifpc02
|
|
sta (sp) ; 65C02 version - saves 2 cycles and one byte
|
|
ldy #1 ; get hi index
|
|
.else
|
|
ldy #0 ; get index
|
|
sta (sp),y ; store lo byte
|
|
iny ; bump idx
|
|
.endif
|
|
pha ; save it
|
|
txa ; get hi byte
|
|
sta (sp),y ; store hi byte
|
|
pla ; get A back
|
|
rts ; done
|
|
|
|
@L1: dey
|
|
@L2: dey
|
|
dec sp+1
|
|
.ifpc02
|
|
bra @L0
|
|
.else
|
|
jmp @L0
|
|
.endif
|
|
|
|
|