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cc65/libsrc/runtime/incsp2.s
cuz 6cbd32b49d Some more 6502 code
git-svn-id: svn://svn.cc65.org/cc65/trunk@485 b7a2c559-68d2-44c3-8de9-860c34a00d81
2000-11-27 23:37:53 +00:00

49 lines
691 B
ArmAsm

;
; Ullrich von Bassewitz, 25.10.2000
;
; CC65 runtime: Increment the stackpointer by 2. For performance reasons,
; this modules does also contain the popax function.
.export popax, incsp2
.importzp sp
; Pop a/x from stack. This function will run directly into incsp2
.proc popax
ldy #1
lda (sp),y ; get hi byte
tax ; into x
.ifpc02
lda (sp) ; get lo byte
.else
dey
lda (sp),y ; get lo byte
.endif
.endproc
.proc incsp2
ldy sp ; 3
iny ; 2
beq @L1 ; 2
iny ; 2
beq @L2 ; 2
sty sp ; 3
rts
@L1: iny ; 2
@L2: sty sp ; 3
inc sp+1 ; 5
rts
.endproc