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84 lines
1.5 KiB
ArmAsm
84 lines
1.5 KiB
ArmAsm
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; Ullrich von Bassewitz, 05.08.1998
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; CC65 runtime: Push ints onto the stack
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;
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;
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; push/pop things on stack
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;
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.export push0, push1, push2, push3, push4, push5
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.export push6, push7, pusha0, pushaFF, pushax
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.export pusha, pushaysp, pushc0, pushc1, pushc2
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.importzp sp
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pushaFF:
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ldx #$FF
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bne pushax
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push7: lda #7
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bne pusha0
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push6: lda #6
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bne pusha0
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push5: lda #5
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bne pusha0
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push4: lda #4
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bne pusha0
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push3: lda #3
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bne pusha0
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push2: lda #2
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bne pusha0
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push1: lda #1
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bne pusha0
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push0: lda #0
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; beq pusha0
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pusha0: ldx #0
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; This function is used *a lot*, so don't call any subroutines here.
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; Beware: The value in ax must not be changed by this function!
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; Beware^2: The optimizer knows about the value of Y after the function
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; returns!
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pushax: ldy sp
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beq @L1
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dey
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beq @L2
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dey
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@L0: sty sp
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ldy #0 ; get index
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sta (sp),y ; store lo byte
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pha ; save it
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txa ; get hi byte
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iny ; bump idx
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sta (sp),y ; store hi byte
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pla ; get A back
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rts ; done
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@L1: dey
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@L2: dey
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dec sp+1
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bne @L0 ; Branch always
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; Push for chars, same warning as above: The optimizer expects the value
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; 0 in the Y register after this function.
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pushc2: lda #2
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bne pusha
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pushc1: lda #1
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bne pusha
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pushc0: lda #0
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beq pusha
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pushaysp:
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lda (sp),y
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pusha: ldy sp
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beq @L1
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dec sp
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ldy #0
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sta (sp),y
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rts
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@L1: dec sp+1
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dec sp
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sta (sp),y
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rts
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