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Update unlzsa2s.asm 

ver.07 by spke (04-05/04/2022, 134(-5) bytes, +1% speed, using self-modifying code by default)
patch
b1ackmai1er 3 years ago
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55b4e1e26d
commit
e1e2c2efa9
1 changed files with 75 additions and 72 deletions
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  1. 147
      Source/HBIOS/unlzsa2s.asm

147
Source/HBIOS/unlzsa2s.asm
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@ -1,5 +1,5 @@
;
; Size-optimized LZSA2 decompressor by spke & uniabis (139 bytes)
; Size-optimized LZSA2 decompressor by spke & uniabis (134 bytes)
;
; ver.00 by spke for LZSA 1.0.0 (02-09/06/2019, 145 bytes);
; ver.01 by spke for LZSA 1.0.5 (24/07/2019, added support for backward decompression);
@ -8,6 +8,9 @@
; ver.04 by spke for LZSA 1.1.0 (26/09/2019, removed usage of IY, added full revision history)
; ver.05 by spke for LZSA 1.1.1 (11/10/2019, 139(-1) bytes, +0.1% speed)
; ver.051 by PSummers (14/1/2020), ROMWBW version.
; ver.06 by spke (11-12/04/2021, added some comments)
; ver.07 by spke (04-05/04/2022, 134(-5) bytes, +1% speed, using self-modifying code by default)
; ver.071 by PSummers (6/1/2023), ROMWBW version.
;
; The data must be compressed using the command line compressor by Emmanuel Marty
; The compression is done as follows:
@ -56,8 +59,8 @@
; 3. This notice may not be removed or altered from any source distribution.
;
; DEFINE BACKWARD_DECOMPRESS ; uncomment for data compressed with option -b
; DEFINE HD64180 ; uncomment for systems using Hitachi HD64180
; #DEFINE BACKWARD_DECOMPRESS ; uncomment for data compressed with option -b (+5 bytes, -3% speed)
; #DEFINE AVOID_SELFMODIFYING_CODE ; uncomment to disallow self-modifying code (-1 byte, -4% speed)
#IFNDEF BACKWARD_DECOMPRESS
@ -65,106 +68,106 @@
#DEFCONT \ inc hl
#DEFINE ADD_OFFSET \
#DEFCONT \ ex de,hl \ add hl,de
#DEFCONT \ add hl,de
#DEFINE BLOCKCOPY \
#DEFCONT \ ldir
#ELSE
#DEFINE NEXT_HL \
#DEFCONT \ dec hl
#DEFINE ADD_OFFSET \
#DEFCONT \ push hl \ or a \ sbc hl,de \ pop de
#DEFCONT \ ld a,e \ sub l \ ld l,a
#DEFCONT \ ld a,d \ sbc h \ ld h,a ; 6*4 = 24t / 6 bytes
#DEFINE BLOCKCOPY \
#DEFCONT \ lddr
#ENDIF
.ECHO "UNLZSA2 for "
#IFDEF HD64180
.ECHO "HD64180"
#DEFINE LD_IX_DE \
#DEFCONT \ ld ixl,e \ ld ixh,d
#DEFINE LD_DE_IX \
#DEFCONT \ ld e,ixl \ ld d,ixh
DLZSA2:
; in many places we assume that B = 0
; flag P in A' signals the need to re-load the nibble store
xor a : ld b,a : exa : jr .ReadToken
CASE00x: ; token "00Z" stands for 5-bit offsets
; (read a nibble for offset bits 1-4 and use the inverted bit Z
; of the token as bit 0 of the offset; set bits 5-15 of the offset to 1)
push af
call skipLDCA \ ld c,a
pop af
cp %00100000 \ rl c \ jr SaveOffset
CASE0xx dec b \ cp %01000000 \ jr c,CASE00x
CASE01x: ; token "01Z" stands for 9-bit offsets
; (read a byte for offset bits 0-7 and use the inverted bit Z
; for bit 8 of the offset; set bits 9-15 of the offset to 1)
cp %01100000
doRLB rl b
OffsetReadC: ld c,(hl) \ NEXT_HL
#IFNDEF AVOID_SELFMODIFYING_CODE
SaveOffset: ld (PrevOffset),bc \ ld b,0
#ELSE
.ECHO "Z80"
#DEFINE LD_IX_DE \
#DEFCONT \ push de \ pop ix
#DEFINE LD_DE_IX \
#DEFCONT \ push ix \ pop de
SaveOffset: push bc \ pop ix \ ld b,0
#ENDIF
.ECHO ".\n"
DLZSA2:
xor a \ ld b,a \ ex af,af' \ jr ReadToken
CASE00x: call ReadNibble
ld e,a \ ld a,c
cp %00100000 \ rl e \ jr SaveOffset
CASE0xx ld d,$FF \ cp %01000000 \ jr c,CASE00x
CASE01x: cp %01100000 \ rl d
OffsetReadE: ld e,(hl) \ NEXT_HL
SaveOffset: LD_IX_DE
MatchLen: and %00000111 \ add 2 \ cp 9
call z,ExtendedCode
MatchLen: and %00000111 \ add a,2 \ cp 9 \ call z,ExtendedCode
CopyMatch: ld c,a
push hl ; BC = len, DE = dest, HL = -offset, SP -> [src]
CopyMatch: ld c,a
ex (sp),hl ; BC = len, DE = -offset, HL = dest, SP -> [src]
ADD_OFFSET ; BC = len, DE = dest, HL = dest+(-offset), SP -> [src]
BLOCKCOPY ; BC = 0, DE = dest
pop hl ; HL = src
#IFNDEF AVOID_SELFMODIFYING_CODE
PrevOffset .EQU $+1 \ ld hl,0
#ELSE
push ix \ pop hl
#ENDIF
ADD_OFFSET
BLOCKCOPY ; BC = 0, DE = dest
pop hl ; HL = src
ReadToken: ld a,(hl) \ NEXT_HL \ push af
and %00011000 \ jr z,NoLiterals
rrca \ rrca \ rrca
call pe,ExtendedCode
rrca \ rrca \ rrca
call pe,ExtendedCode
ld c,a
BLOCKCOPY
ld c,a
BLOCKCOPY
NoLiterals: pop af \ push de
or a \ jp p,CASE0xx
NoLiterals: pop af \ or a \ jp p,CASE0xx
CASE1xx: cp %11000000 \ jr nc,CASE11x
CASE1xx cp %11000000 \ jr c,CASE10x
; token "111" stands for repeat offsets
; (reuse the offset value of the previous match command)
cp %11100000 \ jr nc,MatchLen
CASE10x: call ReadNibble
ld d,a \ ld a,c
cp %10100000 ;: rl d
dec d \ rl d \ .DB $CA ; jr OffsetReadE ; #CA is JP Z,.. to skip all commands in CASE110 before jr OffsetReadE
CASE110: ; token "110" stands for 16-bit offset
; (read a byte for offset bits 8-15, then another byte for offset bits 0-7)
ld b,(hl) \ NEXT_HL \ jr OffsetReadC
CASE110: ld d,(hl) \ NEXT_HL \ jr OffsetReadE
CASE10x: ; token "10Z" stands for 13-bit offsets
; (read a nibble for offset bits 9-12 and use the inverted bit Z
; for bit 8 of the offset, then read a byte for offset bits 0-7.
; set bits 13-15 of the offset to 1. substract 512 from the offset to get the final value)
call ReadNibble \ ld b,a
ld a,c \ cp %10100000
dec b \ jr doRLB
CASE11x: cp %11100000 \ jr c,CASE110
CASE111: LD_DE_IX \ jr MatchLen
ExtendedCode: call ReadNibble \ inc a \ jr z,ExtraByte
sub $F0+1 \ add a,c \ ret
ExtraByte ld a,15 \ add a,c \ add a,(hl) \ NEXT_HL \ ret nc
sub #F0+1 \ add c \ ret
ExtraByte ld a,15 \ add c \ add (hl) \ NEXT_HL \ ret nc
ld a,(hl) \ NEXT_HL
ld b,(hl) \ NEXT_HL \ ret nz
pop de \ pop de ; RET is not needed, because RET from ReadNibble is sufficient
pop bc ; RET is not needed, because RET from ReadNibble is sufficient
ReadNibble: ld c,a \ xor a \ ex af,af' \ ret m
UpdateNibble ld a,(hl) \ or $F0 \ ex af,af'
ld a,(hl) \ NEXT_HL \ or $0F
ReadNibble: ld c,a
skipLDCA xor a \ exa \ ret m
ld a,(hl) \ or #F0 \ exa
ld a,(hl) \ NEXT_HL \ or #0F
rrca \ rrca \ rrca \ rrca \ ret

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