mirror of
https://github.com/cc65/cc65.git
synced 2024-10-30 12:28:25 +00:00
63 lines
717 B
ArmAsm
63 lines
717 B
ArmAsm
|
;
|
||
|
; Ullrich von Bassewitz, 09.12.1998
|
||
|
;
|
||
|
; void __fastcall__ _swap (void* p, void* q, size_t size);
|
||
|
;
|
||
|
|
||
|
.export __swap
|
||
|
.import popax
|
||
|
.importzp ptr1, ptr2, ptr3
|
||
|
|
||
|
|
||
|
__swap: sta ptr3 ; Save size
|
||
|
stx ptr3+1
|
||
|
|
||
|
jsr popax ; Get q
|
||
|
sta ptr2
|
||
|
stx ptr2+1
|
||
|
|
||
|
jsr popax ; Get p
|
||
|
sta ptr1
|
||
|
stx ptr1+1
|
||
|
|
||
|
; Prepare for swap
|
||
|
|
||
|
ldy #$00
|
||
|
|
||
|
; Swap 256 byte blocks
|
||
|
|
||
|
ldx ptr3+1
|
||
|
beq @L2
|
||
|
|
||
|
@L1: lda (ptr1),y
|
||
|
tax
|
||
|
lda (ptr2),y
|
||
|
sta (ptr1),y
|
||
|
txa
|
||
|
sta (ptr2),y
|
||
|
iny
|
||
|
bne @L1
|
||
|
dec ptr3+1
|
||
|
bne @L1
|
||
|
|
||
|
; Swap remaining bytes (Y is zero)
|
||
|
|
||
|
@L2: ldx ptr3
|
||
|
beq @L9
|
||
|
|
||
|
@L3: lda (ptr1),y
|
||
|
tax
|
||
|
lda (ptr2),y
|
||
|
sta (ptr1),y
|
||
|
txa
|
||
|
sta (ptr2),y
|
||
|
iny
|
||
|
dec ptr3
|
||
|
bne @L3
|
||
|
|
||
|
; Done
|
||
|
|
||
|
@L9: rts
|
||
|
|
||
|
|