mirror of
https://github.com/emmanuel-marty/lzsa.git
synced 2024-11-25 10:30:45 +00:00
not-fast 65816 version
This commit is contained in:
parent
01228f3eeb
commit
2442d6e489
@ -68,7 +68,7 @@ LARGE_VARLEN_LITERALS ; handle 16 bits literals count
|
|||||||
JSR GETLARGESRC ; grab low 8 bits in X, high 8 bits in A
|
JSR GETLARGESRC ; grab low 8 bits in X, high 8 bits in A
|
||||||
TAY ; put high 8 bits in Y
|
TAY ; put high 8 bits in Y
|
||||||
TXA
|
TXA
|
||||||
JMP PREPARE_COPY_LARGE_LITERALS
|
BCS PREPARE_COPY_LARGE_LITERALS ; (*like JMP PREPARE_COPY_LITERALS_DIRECT but shorter)
|
||||||
|
|
||||||
PREPARE_COPY_LITERALS
|
PREPARE_COPY_LITERALS
|
||||||
TAX
|
TAX
|
||||||
|
281
asm/65816/decompress_v1.asm
Normal file
281
asm/65816/decompress_v1.asm
Normal file
@ -0,0 +1,281 @@
|
|||||||
|
; -----------------------------------------------------------------------------
|
||||||
|
; Decompress raw LZSA1 block. Create one with lzsa -r <original_file> <compressed_file>
|
||||||
|
;
|
||||||
|
; in:
|
||||||
|
; * LZSA_SRC_LO/LZSA_SRC_HI/LZSA_SRC_BANK contain the compressed raw block address
|
||||||
|
; * LZSA_DST_LO/LZSA_DST_HI/LZSA_DST_BANK contain the destination buffer address
|
||||||
|
;
|
||||||
|
; out:
|
||||||
|
; * LZSA_DST_LO/LZSA_DST_HI/LZSA_DST_BANK contain the last decompressed byte address, +1
|
||||||
|
;
|
||||||
|
; -----------------------------------------------------------------------------
|
||||||
|
; Backward decompression is also supported, use lzsa -r -b <original_file> <compressed_file>
|
||||||
|
; To use it, also define BACKWARD_DECOMPRESS=1 before including this code!
|
||||||
|
;
|
||||||
|
; in:
|
||||||
|
; * LZSA_SRC_LO/LZSA_SRC_HI/LZSA_SRC_BANK must contain the address of the last byte of compressed data
|
||||||
|
; * LZSA_DST_LO/LZSA_DST_HI/LZSA_DST_BANK must contain the address of the last byte of the destination buffer
|
||||||
|
;
|
||||||
|
; out:
|
||||||
|
; * LZSA_DST_LO/LZSA_DST_HI/BANK contain the last decompressed byte address, -1
|
||||||
|
;
|
||||||
|
; -----------------------------------------------------------------------------
|
||||||
|
;
|
||||||
|
; Copyright (C) 2019-2020 Emmanuel Marty, Peter Ferrie
|
||||||
|
;
|
||||||
|
; This software is provided 'as-is', without any express or implied
|
||||||
|
; warranty. In no event will the authors be held liable for any damages
|
||||||
|
; arising from the use of this software.
|
||||||
|
;
|
||||||
|
; Permission is granted to anyone to use this software for any purpose,
|
||||||
|
; including commercial applications, and to alter it and redistribute it
|
||||||
|
; freely, subject to the following restrictions:
|
||||||
|
;
|
||||||
|
; 1. The origin of this software must not be misrepresented; you must not
|
||||||
|
; claim that you wrote the original software. If you use this software
|
||||||
|
; in a product, an acknowledgment in the product documentation would be
|
||||||
|
; appreciated but is not required.
|
||||||
|
; 2. Altered source versions must be plainly marked as such, and must not be
|
||||||
|
; misrepresented as being the original software.
|
||||||
|
; 3. This notice may not be removed or altered from any source distribution.
|
||||||
|
; -----------------------------------------------------------------------------
|
||||||
|
|
||||||
|
!cpu 65816
|
||||||
|
DECOMPRESS_LZSA1
|
||||||
|
SEP #$30
|
||||||
|
!as
|
||||||
|
!rs
|
||||||
|
LDY #$00
|
||||||
|
|
||||||
|
DECODE_TOKEN
|
||||||
|
JSR GETSRC ; read token byte: O|LLL|MMMM
|
||||||
|
PHA ; preserve token on stack
|
||||||
|
|
||||||
|
AND #$70 ; isolate literals count
|
||||||
|
BEQ NO_LITERALS ; skip if no literals to copy
|
||||||
|
CMP #$70 ; LITERALS_RUN_LEN?
|
||||||
|
BNE PREPARE_COPY_LITERALS ; if not, count is directly embedded in token
|
||||||
|
|
||||||
|
JSR GETSRC ; get extra byte of variable literals count
|
||||||
|
; the carry is always set by the CMP above
|
||||||
|
; GETSRC doesn't change it
|
||||||
|
SBC #$F9 ; (LITERALS_RUN_LEN)
|
||||||
|
BCC PREPARE_COPY_LITERALS_DIRECT
|
||||||
|
BEQ LARGE_VARLEN_LITERALS ; if adding up to zero, go grab 16-bit count
|
||||||
|
|
||||||
|
JSR GETSRC ; get single extended byte of variable literals count
|
||||||
|
INY ; add 256 to literals count
|
||||||
|
BCS PREPARE_COPY_LITERALS_DIRECT ; (*like JMP PREPARE_COPY_LITERALS_DIRECT but shorter)
|
||||||
|
|
||||||
|
LARGE_VARLEN_LITERALS ; handle 16 bits literals count
|
||||||
|
; literals count = directly these 16 bits
|
||||||
|
JSR GETLARGESRC ; grab low 8 bits in X, high 8 bits in A
|
||||||
|
TAY ; put high 8 bits in Y
|
||||||
|
TXA
|
||||||
|
BCS PREPARE_COPY_LARGE_LITERALS ; (*like JMP PREPARE_COPY_LITERALS_DIRECT but shorter)
|
||||||
|
|
||||||
|
PREPARE_COPY_LITERALS
|
||||||
|
TAX
|
||||||
|
LDA SHIFT_TABLE-1,X ; shift literals length into place
|
||||||
|
; -1 because position 00 is reserved
|
||||||
|
PREPARE_COPY_LITERALS_DIRECT
|
||||||
|
TAX
|
||||||
|
|
||||||
|
PREPARE_COPY_LARGE_LITERALS
|
||||||
|
BEQ COPY_LITERALS
|
||||||
|
INY
|
||||||
|
|
||||||
|
COPY_LITERALS
|
||||||
|
JSR GETPUT ; copy one byte of literals
|
||||||
|
DEX
|
||||||
|
BNE COPY_LITERALS
|
||||||
|
DEY
|
||||||
|
BNE COPY_LITERALS
|
||||||
|
|
||||||
|
NO_LITERALS
|
||||||
|
PLA ; retrieve token from stack
|
||||||
|
PHA ; preserve token again
|
||||||
|
BMI GET_LONG_OFFSET ; $80: 16 bit offset
|
||||||
|
|
||||||
|
JSR GETSRC ; get 8 bit offset from stream in A
|
||||||
|
TAX ; save for later
|
||||||
|
LDA #$FF ; high 8 bits
|
||||||
|
BNE GOT_OFFSET ; go prepare match
|
||||||
|
; (*like JMP GOT_OFFSET but shorter)
|
||||||
|
|
||||||
|
SHORT_VARLEN_MATCHLEN
|
||||||
|
JSR GETSRC ; get single extended byte of variable match len
|
||||||
|
INY ; add 256 to match length
|
||||||
|
|
||||||
|
PREPARE_COPY_MATCH
|
||||||
|
TAX
|
||||||
|
PREPARE_COPY_MATCH_Y
|
||||||
|
TXA
|
||||||
|
BEQ COPY_MATCH_LOOP
|
||||||
|
INY
|
||||||
|
|
||||||
|
COPY_MATCH_LOOP
|
||||||
|
LDA $AAAAAA ; get one byte of backreference
|
||||||
|
JSR PUTDST ; copy to destination
|
||||||
|
|
||||||
|
REP #$20
|
||||||
|
!ifdef BACKWARD_DECOMPRESS {
|
||||||
|
|
||||||
|
; Backward decompression -- put backreference bytes backward
|
||||||
|
|
||||||
|
DEC COPY_MATCH_LOOP+1
|
||||||
|
|
||||||
|
} else {
|
||||||
|
|
||||||
|
; Forward decompression -- put backreference bytes forward
|
||||||
|
|
||||||
|
INC COPY_MATCH_LOOP+1
|
||||||
|
|
||||||
|
}
|
||||||
|
SEP #$20
|
||||||
|
|
||||||
|
DEX
|
||||||
|
BNE COPY_MATCH_LOOP
|
||||||
|
DEY
|
||||||
|
BNE COPY_MATCH_LOOP
|
||||||
|
BEQ DECODE_TOKEN ; (*like JMP DECODE_TOKEN but shorter)
|
||||||
|
|
||||||
|
GET_LONG_OFFSET ; handle 16 bit offset:
|
||||||
|
JSR GETLARGESRC ; grab low 8 bits in X, high 8 bits in A
|
||||||
|
|
||||||
|
GOT_OFFSET
|
||||||
|
|
||||||
|
!ifdef BACKWARD_DECOMPRESS {
|
||||||
|
|
||||||
|
; Backward decompression - substract match offset
|
||||||
|
|
||||||
|
STA OFFSHI ; store high 8 bits of offset
|
||||||
|
STX OFFSLO
|
||||||
|
|
||||||
|
SEC ; substract dest - match offset
|
||||||
|
REP #$20
|
||||||
|
!al
|
||||||
|
LDA PUTDST+1
|
||||||
|
OFFSLO = *+1
|
||||||
|
OFFSHI = *+2
|
||||||
|
SBC #$AAAA ; 16 bits
|
||||||
|
STA COPY_MATCH_LOOP+1 ; store back reference address
|
||||||
|
SEP #$20
|
||||||
|
!as
|
||||||
|
SEC
|
||||||
|
|
||||||
|
} else {
|
||||||
|
|
||||||
|
; Forward decompression - add match offset
|
||||||
|
|
||||||
|
STA OFFSHI ; store high 8 bits of offset
|
||||||
|
TXA
|
||||||
|
|
||||||
|
CLC ; add dest + match offset
|
||||||
|
ADC PUTDST+1 ; low 8 bits
|
||||||
|
STA COPY_MATCH_LOOP+1 ; store back reference address
|
||||||
|
OFFSHI = *+1
|
||||||
|
LDA #$AA ; high 8 bits
|
||||||
|
|
||||||
|
ADC PUTDST+2
|
||||||
|
STA COPY_MATCH_LOOP+2 ; store high 8 bits of address
|
||||||
|
|
||||||
|
}
|
||||||
|
|
||||||
|
LDA PUTDST+3 ; bank
|
||||||
|
STA COPY_MATCH_LOOP+3 ; store back reference address
|
||||||
|
|
||||||
|
PLA ; retrieve token from stack again
|
||||||
|
AND #$0F ; isolate match len (MMMM)
|
||||||
|
ADC #$02 ; plus carry which is always set by the high ADC
|
||||||
|
CMP #$12 ; MATCH_RUN_LEN?
|
||||||
|
BCC PREPARE_COPY_MATCH ; if not, count is directly embedded in token
|
||||||
|
|
||||||
|
JSR GETSRC ; get extra byte of variable match length
|
||||||
|
; the carry is always set by the CMP above
|
||||||
|
; GETSRC doesn't change it
|
||||||
|
SBC #$EE ; add MATCH_RUN_LEN and MIN_MATCH_SIZE to match length
|
||||||
|
BCC PREPARE_COPY_MATCH
|
||||||
|
BNE SHORT_VARLEN_MATCHLEN
|
||||||
|
|
||||||
|
; Handle 16 bits match length
|
||||||
|
JSR GETLARGESRC ; grab low 8 bits in X, high 8 bits in A
|
||||||
|
TAY ; put high 8 bits in Y
|
||||||
|
; large match length with zero high byte?
|
||||||
|
BNE PREPARE_COPY_MATCH_Y ; if not, continue
|
||||||
|
|
||||||
|
DECOMPRESSION_DONE
|
||||||
|
RTS
|
||||||
|
|
||||||
|
SHIFT_TABLE
|
||||||
|
!BYTE $00,$00,$00,$00,$00,$00,$00,$00,$00,$00,$00,$00,$00,$00,$00
|
||||||
|
!BYTE $01,$01,$01,$01,$01,$01,$01,$01,$01,$01,$01,$01,$01,$01,$01,$01
|
||||||
|
!BYTE $02,$02,$02,$02,$02,$02,$02,$02,$02,$02,$02,$02,$02,$02,$02,$02
|
||||||
|
!BYTE $03,$03,$03,$03,$03,$03,$03,$03,$03,$03,$03,$03,$03,$03,$03,$03
|
||||||
|
!BYTE $04,$04,$04,$04,$04,$04,$04,$04,$04,$04,$04,$04,$04,$04,$04,$04
|
||||||
|
!BYTE $05,$05,$05,$05,$05,$05,$05,$05,$05,$05,$05,$05,$05,$05,$05,$05
|
||||||
|
!BYTE $06,$06,$06,$06,$06,$06,$06,$06,$06,$06,$06,$06,$06,$06,$06,$06
|
||||||
|
!BYTE $07,$07,$07,$07,$07,$07,$07,$07,$07,$07,$07,$07,$07,$07,$07,$07
|
||||||
|
|
||||||
|
!ifdef BACKWARD_DECOMPRESS {
|
||||||
|
|
||||||
|
; Backward decompression -- get and put bytes backward
|
||||||
|
|
||||||
|
GETPUT
|
||||||
|
JSR GETSRC
|
||||||
|
PUTDST
|
||||||
|
LZSA_DST_LO = *+1
|
||||||
|
LZSA_DST_HI = *+2
|
||||||
|
LZSA_DST_BANK = *+3
|
||||||
|
STA $AAAAAA
|
||||||
|
REP #$20
|
||||||
|
DEC PUTDST+1
|
||||||
|
SEP #$20
|
||||||
|
RTS
|
||||||
|
|
||||||
|
GETLARGESRC
|
||||||
|
JSR GETSRC ; grab low 8 bits
|
||||||
|
TAX ; move to X
|
||||||
|
; fall through grab high 8 bits
|
||||||
|
|
||||||
|
GETSRC
|
||||||
|
LZSA_SRC_LO = *+1
|
||||||
|
LZSA_SRC_HI = *+2
|
||||||
|
LZSA_SRC_BANK = *+3
|
||||||
|
LDA $AAAAAA
|
||||||
|
REP #$20
|
||||||
|
DEC GETSRC+1
|
||||||
|
SEP #$20
|
||||||
|
RTS
|
||||||
|
|
||||||
|
} else {
|
||||||
|
|
||||||
|
; Forward decompression -- get and put bytes forward
|
||||||
|
|
||||||
|
GETPUT
|
||||||
|
JSR GETSRC
|
||||||
|
PUTDST
|
||||||
|
LZSA_DST_LO = *+1
|
||||||
|
LZSA_DST_HI = *+2
|
||||||
|
LZSA_DST_BANK = *+3
|
||||||
|
STA $AAAAAA
|
||||||
|
REP #$20
|
||||||
|
INC PUTDST+1
|
||||||
|
SEP #$20
|
||||||
|
RTS
|
||||||
|
|
||||||
|
GETLARGESRC
|
||||||
|
JSR GETSRC ; grab low 8 bits
|
||||||
|
TAX ; move to X
|
||||||
|
; fall through grab high 8 bits
|
||||||
|
|
||||||
|
GETSRC
|
||||||
|
LZSA_SRC_LO = *+1
|
||||||
|
LZSA_SRC_HI = *+2
|
||||||
|
LZSA_SRC_BANK = *+3
|
||||||
|
LDA $AAAAAA
|
||||||
|
REP #$20
|
||||||
|
INC GETSRC+1
|
||||||
|
SEP #$20
|
||||||
|
RTS
|
||||||
|
}
|
338
asm/65816/decompress_v2.asm
Normal file
338
asm/65816/decompress_v2.asm
Normal file
@ -0,0 +1,338 @@
|
|||||||
|
; -----------------------------------------------------------------------------
|
||||||
|
; Decompress raw LZSA2 block.
|
||||||
|
; Create one with lzsa -r -f2 <original_file> <compressed_file>
|
||||||
|
;
|
||||||
|
; in:
|
||||||
|
; * LZSA_SRC_LO/LZSA_SRC_HI/LZSA_SRC_BANK contain the compressed raw block address
|
||||||
|
; * LZSA_DST_LO/LZSA_DST_HI/LZSA_DST_BANK contain the destination buffer address
|
||||||
|
;
|
||||||
|
; out:
|
||||||
|
; * LZSA_DST_LO/LZSA_DST_HI/LZSA_DST_BANK contain the last decompressed byte address, +1
|
||||||
|
;
|
||||||
|
; -----------------------------------------------------------------------------
|
||||||
|
; Backward decompression is also supported, use lzsa -r -b -f2 <original_file> <compressed_file>
|
||||||
|
; To use it, also define BACKWARD_DECOMPRESS=1 before including this code!
|
||||||
|
;
|
||||||
|
; in:
|
||||||
|
; * LZSA_SRC_LO/LZSA_SRC_HI/LZSA_SRC_BANK must contain the address of the last byte of compressed data
|
||||||
|
; * LZSA_DST_LO/LZSA_DST_HI/LZSA_DST_BANK must contain the address of the last byte of the destination buffer
|
||||||
|
;
|
||||||
|
; out:
|
||||||
|
; * LZSA_DST_LO/LZSA_DST_HI/BANK contain the last decompressed byte address, -1
|
||||||
|
;
|
||||||
|
; -----------------------------------------------------------------------------
|
||||||
|
;
|
||||||
|
; Copyright (C) 2019-2020 Emmanuel Marty, Peter Ferrie
|
||||||
|
;
|
||||||
|
; This software is provided 'as-is', without any express or implied
|
||||||
|
; warranty. In no event will the authors be held liable for any damages
|
||||||
|
; arising from the use of this software.
|
||||||
|
;
|
||||||
|
; Permission is granted to anyone to use this software for any purpose,
|
||||||
|
; including commercial applications, and to alter it and redistribute it
|
||||||
|
; freely, subject to the following restrictions:
|
||||||
|
;
|
||||||
|
; 1. The origin of this software must not be misrepresented; you must not
|
||||||
|
; claim that you wrote the original software. If you use this software
|
||||||
|
; in a product, an acknowledgment in the product documentation would be
|
||||||
|
; appreciated but is not required.
|
||||||
|
; 2. Altered source versions must be plainly marked as such, and must not be
|
||||||
|
; misrepresented as being the original software.
|
||||||
|
; 3. This notice may not be removed or altered from any source distribution.
|
||||||
|
; -----------------------------------------------------------------------------
|
||||||
|
|
||||||
|
!cpu 65816
|
||||||
|
NIBCOUNT = $FC ; zero-page location for temp offset
|
||||||
|
|
||||||
|
DECOMPRESS_LZSA2
|
||||||
|
SEP #$30
|
||||||
|
!as
|
||||||
|
!rs
|
||||||
|
LDY #$00
|
||||||
|
STY NIBCOUNT
|
||||||
|
|
||||||
|
DECODE_TOKEN
|
||||||
|
JSR GETSRC ; read token byte: XYZ|LL|MMM
|
||||||
|
PHA ; preserve token on stack
|
||||||
|
|
||||||
|
AND #$18 ; isolate literals count (LL)
|
||||||
|
BEQ NO_LITERALS ; skip if no literals to copy
|
||||||
|
CMP #$18 ; LITERALS_RUN_LEN_V2?
|
||||||
|
BCC PREPARE_COPY_LITERALS ; if less, count is directly embedded in token
|
||||||
|
|
||||||
|
JSR GETNIBBLE ; get extra literals length nibble
|
||||||
|
; add nibble to len from token
|
||||||
|
ADC #$02 ; (LITERALS_RUN_LEN_V2) minus carry
|
||||||
|
CMP #$12 ; LITERALS_RUN_LEN_V2 + 15 ?
|
||||||
|
BCC PREPARE_COPY_LITERALS_DIRECT ; if less, literals count is complete
|
||||||
|
|
||||||
|
JSR GETSRC ; get extra byte of variable literals count
|
||||||
|
; the carry is always set by the CMP above
|
||||||
|
; GETSRC doesn't change it
|
||||||
|
SBC #$EE ; overflow?
|
||||||
|
BRA PREPARE_COPY_LITERALS_DIRECT
|
||||||
|
|
||||||
|
PREPARE_COPY_LITERALS_LARGE
|
||||||
|
; handle 16 bits literals count
|
||||||
|
; literals count = directly these 16 bits
|
||||||
|
JSR GETLARGESRC ; grab low 8 bits in X, high 8 bits in A
|
||||||
|
TAY ; put high 8 bits in Y
|
||||||
|
BCS PREPARE_COPY_LITERALS_HIGH ; (*same as JMP PREPARE_COPY_LITERALS_HIGH but shorter)
|
||||||
|
|
||||||
|
PREPARE_COPY_LITERALS
|
||||||
|
LSR ; shift literals count into place
|
||||||
|
LSR
|
||||||
|
LSR
|
||||||
|
|
||||||
|
PREPARE_COPY_LITERALS_DIRECT
|
||||||
|
TAX
|
||||||
|
BCS PREPARE_COPY_LITERALS_LARGE ; if so, literals count is large
|
||||||
|
|
||||||
|
PREPARE_COPY_LITERALS_HIGH
|
||||||
|
TXA
|
||||||
|
BEQ COPY_LITERALS
|
||||||
|
INY
|
||||||
|
|
||||||
|
COPY_LITERALS
|
||||||
|
JSR GETPUT ; copy one byte of literals
|
||||||
|
DEX
|
||||||
|
BNE COPY_LITERALS
|
||||||
|
DEY
|
||||||
|
BNE COPY_LITERALS
|
||||||
|
|
||||||
|
NO_LITERALS
|
||||||
|
PLA ; retrieve token from stack
|
||||||
|
PHA ; preserve token again
|
||||||
|
ASL
|
||||||
|
BCS REPMATCH_OR_LARGE_OFFSET ; 1YZ: rep-match or 13/16 bit offset
|
||||||
|
|
||||||
|
ASL ; 0YZ: 5 or 9 bit offset
|
||||||
|
BCS OFFSET_9_BIT
|
||||||
|
|
||||||
|
; 00Z: 5 bit offset
|
||||||
|
|
||||||
|
LDX #$FF ; set offset bits 15-8 to 1
|
||||||
|
|
||||||
|
JSR GETCOMBINEDBITS ; rotate Z bit into bit 0, read nibble for bits 4-1
|
||||||
|
ORA #$E0 ; set bits 7-5 to 1
|
||||||
|
BNE GOT_OFFSET_LO ; go store low byte of match offset and prepare match
|
||||||
|
|
||||||
|
OFFSET_9_BIT ; 01Z: 9 bit offset
|
||||||
|
;;ASL ; shift Z (offset bit 8) in place
|
||||||
|
ROL
|
||||||
|
ROL
|
||||||
|
AND #$01
|
||||||
|
EOR #$FF ; set offset bits 15-9 to 1
|
||||||
|
BNE GOT_OFFSET_HI ; go store high byte, read low byte of match offset and prepare match
|
||||||
|
; (*same as JMP GOT_OFFSET_HI but shorter)
|
||||||
|
|
||||||
|
REPMATCH_OR_LARGE_OFFSET
|
||||||
|
ASL ; 13 bit offset?
|
||||||
|
BCS REPMATCH_OR_16_BIT ; handle rep-match or 16-bit offset if not
|
||||||
|
|
||||||
|
; 10Z: 13 bit offset
|
||||||
|
|
||||||
|
JSR GETCOMBINEDBITS ; rotate Z bit into bit 8, read nibble for bits 12-9
|
||||||
|
ADC #$DE ; set bits 15-13 to 1 and substract 2 (to substract 512)
|
||||||
|
BNE GOT_OFFSET_HI ; go store high byte, read low byte of match offset and prepare match
|
||||||
|
; (*same as JMP GOT_OFFSET_HI but shorter)
|
||||||
|
|
||||||
|
REPMATCH_OR_16_BIT ; rep-match or 16 bit offset
|
||||||
|
;;ASL ; XYZ=111?
|
||||||
|
BMI REP_MATCH ; reuse previous offset if so (rep-match)
|
||||||
|
|
||||||
|
; 110: handle 16 bit offset
|
||||||
|
JSR GETSRC ; grab high 8 bits
|
||||||
|
GOT_OFFSET_HI
|
||||||
|
TAX
|
||||||
|
JSR GETSRC ; grab low 8 bits
|
||||||
|
GOT_OFFSET_LO
|
||||||
|
STA OFFSLO ; store low byte of match offset
|
||||||
|
STX OFFSHI ; store high byte of match offset
|
||||||
|
|
||||||
|
REP_MATCH
|
||||||
|
!ifdef BACKWARD_DECOMPRESS {
|
||||||
|
|
||||||
|
; Backward decompression - substract match offset
|
||||||
|
|
||||||
|
SEC ; add dest + match offset
|
||||||
|
REP #$20
|
||||||
|
!al
|
||||||
|
LDA PUTDST+1 ; 16 bits
|
||||||
|
OFFSLO = *+1
|
||||||
|
OFFSHI = *+2
|
||||||
|
SBC #$AAAA
|
||||||
|
STA COPY_MATCH_LOOP+1 ; store back reference address
|
||||||
|
SEP #$20
|
||||||
|
!as
|
||||||
|
SEC
|
||||||
|
|
||||||
|
} else {
|
||||||
|
|
||||||
|
; Forward decompression - add match offset
|
||||||
|
|
||||||
|
CLC ; add dest + match offset
|
||||||
|
REP #$20
|
||||||
|
!al
|
||||||
|
LDA PUTDST+1 ; 16 bits
|
||||||
|
OFFSLO = *+1
|
||||||
|
OFFSHI = *+2
|
||||||
|
ADC #$AAAA
|
||||||
|
STA COPY_MATCH_LOOP+1 ; store back reference address
|
||||||
|
SEP #$20
|
||||||
|
!as
|
||||||
|
}
|
||||||
|
|
||||||
|
LDA PUTDST+3 ; bank
|
||||||
|
STA COPY_MATCH_LOOP+3 ; store back reference address
|
||||||
|
|
||||||
|
PLA ; retrieve token from stack again
|
||||||
|
AND #$07 ; isolate match len (MMM)
|
||||||
|
ADC #$01 ; add MIN_MATCH_SIZE_V2 and carry
|
||||||
|
CMP #$09 ; MIN_MATCH_SIZE_V2 + MATCH_RUN_LEN_V2?
|
||||||
|
BCC PREPARE_COPY_MATCH ; if less, length is directly embedded in token
|
||||||
|
|
||||||
|
JSR GETNIBBLE ; get extra match length nibble
|
||||||
|
; add nibble to len from token
|
||||||
|
ADC #$08 ; (MIN_MATCH_SIZE_V2 + MATCH_RUN_LEN_V2) minus carry
|
||||||
|
CMP #$18 ; MIN_MATCH_SIZE_V2 + MATCH_RUN_LEN_V2 + 15?
|
||||||
|
BCC PREPARE_COPY_MATCH ; if less, match length is complete
|
||||||
|
|
||||||
|
JSR GETSRC ; get extra byte of variable match length
|
||||||
|
; the carry is always set by the CMP above
|
||||||
|
; GETSRC doesn't change it
|
||||||
|
SBC #$E8 ; overflow?
|
||||||
|
|
||||||
|
PREPARE_COPY_MATCH
|
||||||
|
TAX
|
||||||
|
BCC PREPARE_COPY_MATCH_Y ; if not, the match length is complete
|
||||||
|
BEQ DECOMPRESSION_DONE ; if EOD code, bail
|
||||||
|
|
||||||
|
; Handle 16 bits match length
|
||||||
|
JSR GETLARGESRC ; grab low 8 bits in X, high 8 bits in A
|
||||||
|
TAY ; put high 8 bits in Y
|
||||||
|
|
||||||
|
PREPARE_COPY_MATCH_Y
|
||||||
|
TXA
|
||||||
|
BEQ COPY_MATCH_LOOP
|
||||||
|
INY
|
||||||
|
|
||||||
|
COPY_MATCH_LOOP
|
||||||
|
LDA $AAAAAA ; get one byte of backreference
|
||||||
|
JSR PUTDST ; copy to destination
|
||||||
|
|
||||||
|
REP #$20
|
||||||
|
!ifdef BACKWARD_DECOMPRESS {
|
||||||
|
|
||||||
|
; Backward decompression -- put backreference bytes backward
|
||||||
|
|
||||||
|
DEC COPY_MATCH_LOOP+1
|
||||||
|
|
||||||
|
} else {
|
||||||
|
|
||||||
|
; Forward decompression -- put backreference bytes forward
|
||||||
|
|
||||||
|
INC COPY_MATCH_LOOP+1
|
||||||
|
|
||||||
|
}
|
||||||
|
SEP #$20
|
||||||
|
|
||||||
|
DEX
|
||||||
|
BNE COPY_MATCH_LOOP
|
||||||
|
DEY
|
||||||
|
BNE COPY_MATCH_LOOP
|
||||||
|
JMP DECODE_TOKEN
|
||||||
|
|
||||||
|
GETCOMBINEDBITS
|
||||||
|
EOR #$80
|
||||||
|
ASL
|
||||||
|
PHP
|
||||||
|
|
||||||
|
JSR GETNIBBLE ; get nibble into bits 0-3 (for offset bits 1-4)
|
||||||
|
PLP ; merge Z bit as the carry bit (for offset bit 0)
|
||||||
|
COMBINEDBITZ
|
||||||
|
ROL ; nibble -> bits 1-4; carry(!Z bit) -> bit 0 ; carry cleared
|
||||||
|
DECOMPRESSION_DONE
|
||||||
|
RTS
|
||||||
|
|
||||||
|
GETNIBBLE
|
||||||
|
NIBBLES = *+1
|
||||||
|
LDA #$AA
|
||||||
|
LSR NIBCOUNT
|
||||||
|
BCC NEED_NIBBLES
|
||||||
|
AND #$0F ; isolate low 4 bits of nibble
|
||||||
|
RTS
|
||||||
|
|
||||||
|
NEED_NIBBLES
|
||||||
|
INC NIBCOUNT
|
||||||
|
JSR GETSRC ; get 2 nibbles
|
||||||
|
STA NIBBLES
|
||||||
|
LSR
|
||||||
|
LSR
|
||||||
|
LSR
|
||||||
|
LSR
|
||||||
|
SEC
|
||||||
|
RTS
|
||||||
|
|
||||||
|
!ifdef BACKWARD_DECOMPRESS {
|
||||||
|
|
||||||
|
; Backward decompression -- get and put bytes backward
|
||||||
|
|
||||||
|
GETPUT
|
||||||
|
JSR GETSRC
|
||||||
|
PUTDST
|
||||||
|
LZSA_DST_LO = *+1
|
||||||
|
LZSA_DST_HI = *+2
|
||||||
|
LZSA_DST_BANK = *+3
|
||||||
|
STA $AAAAAA
|
||||||
|
REP #$20
|
||||||
|
DEC PUTDST+1
|
||||||
|
SEP #$20
|
||||||
|
RTS
|
||||||
|
|
||||||
|
GETLARGESRC
|
||||||
|
JSR GETSRC ; grab low 8 bits
|
||||||
|
TAX ; move to X
|
||||||
|
; fall through grab high 8 bits
|
||||||
|
|
||||||
|
GETSRC
|
||||||
|
LZSA_SRC_LO = *+1
|
||||||
|
LZSA_SRC_HI = *+2
|
||||||
|
LZSA_SRC_BANK = *+3
|
||||||
|
LDA $AAAAAA
|
||||||
|
REP #$20
|
||||||
|
DEC GETSRC+1
|
||||||
|
SEP #$20
|
||||||
|
RTS
|
||||||
|
|
||||||
|
} else {
|
||||||
|
|
||||||
|
; Forward decompression -- get and put bytes forward
|
||||||
|
|
||||||
|
GETPUT
|
||||||
|
JSR GETSRC
|
||||||
|
PUTDST
|
||||||
|
LZSA_DST_LO = *+1
|
||||||
|
LZSA_DST_HI = *+2
|
||||||
|
LZSA_DST_BANK = *+3
|
||||||
|
STA $AAAAAA
|
||||||
|
REP #$20
|
||||||
|
INC PUTDST+1
|
||||||
|
SEP #$20
|
||||||
|
RTS
|
||||||
|
|
||||||
|
GETLARGESRC
|
||||||
|
JSR GETSRC ; grab low 8 bits
|
||||||
|
TAX ; move to X
|
||||||
|
; fall through grab high 8 bits
|
||||||
|
|
||||||
|
GETSRC
|
||||||
|
LZSA_SRC_LO = *+1
|
||||||
|
LZSA_SRC_HI = *+2
|
||||||
|
LZSA_SRC_BANK = *+3
|
||||||
|
LDA $AAAAAA
|
||||||
|
REP #$20
|
||||||
|
INC GETSRC+1
|
||||||
|
SEP #$20
|
||||||
|
RTS
|
||||||
|
}
|
Loading…
Reference in New Issue
Block a user