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Sqeezed a few bytes out of the copydata function

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git-svn-id: svn://svn.cc65.org/cc65/trunk@3320 b7a2c559-68d2-44c3-8de9-860c34a00d81
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cuz 2004-12-01 12:00:50 +00:00
parent 0ab513b254
commit 6de079ee57
1 changed files with 22 additions and 26 deletions
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48
libsrc/common/copydata.s
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@ -1,53 +1,49 @@
;
; Ullrich von Bassewitz, 07.12.1998
; Ullrich von Bassewitz, 1998-12-07, 2004-12-01
;
; Copy the data segment from the LOAD to the RUN location
;
.export copydata
.import __DATA_LOAD__, __DATA_RUN__, __DATA_SIZE__
.importzp ptr1, ptr2
.importzp ptr1, ptr2, tmp1
copydata:
lda #<__DATA_LOAD__ ; Source pointer
lda #<__DATA_LOAD__ ; Source pointer
sta ptr1
lda #>__DATA_LOAD__
sta ptr1+1
lda #<__DATA_RUN__ ; Target pointer
lda #<__DATA_RUN__ ; Target pointer
sta ptr2
lda #>__DATA_RUN__
sta ptr2+1
ldy #$00
ldx #>__DATA_SIZE__ ; Get page count
beq @L2 ; No full pages
ldx #<~__DATA_SIZE__
lda #>~__DATA_SIZE__ ; Use -(__DATASIZE__+1)
sta tmp1
ldy #$00
; Copy full pages
; Copy loop
@L1: lda (ptr1),y
sta (ptr2),y
iny
bne @L1
inc ptr1+1
inc ptr2+1 ; Bump pointers
dex
bne @L1
@L1: inx
beq @L3
; Copy last page (remember: y contains zero)
@L2: lda (ptr1),y
sta (ptr2),y
iny
bne @L1
inc ptr1+1
inc ptr2+1 ; Bump pointers
bne @L1 ; Branch always (hopefully)
@L2: ldx #<__DATA_SIZE__ ; Get remaining bytes
beq @L4
; Bump the high counter byte
@L3: lda (ptr1),y
sta (ptr2),y
iny
dex
bne @L3
@L3: inc tmp1
bne @L2
; Done
@L4: rts
rts