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incorporated improvements by uniabis

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also, slightly faster decompression for fast packer in backwards mode
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introspec 2019-07-31 20:42:47 +01:00 committed by GitHub
parent ac3bf78273
commit 51ef92cdab
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2 changed files with 51 additions and 48 deletions
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48
asm/z80/unlzsa1_fast_v1.asm
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@ -1,5 +1,6 @@
;
; Speed-optimized LZSA decompressor by spke (v.1 03-25/04/2019, 110 bytes)
; Speed-optimized LZSA1 decompressor by spke (v.1 03-25/04/2019, 109 bytes);
; with improvements by uniabis (30/07/2019, -1 byte, +3% speed).
;
; The data must be compressed using the command line compressor by Emmanuel Marty
; The compression is done as follows:
@ -12,7 +13,7 @@
;
; ld hl,FirstByteOfCompressedData
; ld de,FirstByteOfMemoryForDecompressedData
; call DecompressLZSA
; call DecompressLZSA1
;
; Backward compression is also supported; you can compress files backward using:
;
@ -22,11 +23,11 @@
;
; ld hl,LastByteOfCompressedData
; ld de,LastByteOfMemoryForDecompressedData
; call DecompressLZSA
; call DecompressLZSA1
;
; (do not forget to uncomment the BACKWARD_DECOMPRESS option in the decompressor).
;
; Of course, LZSA compression algorithm is (c) 2019 Emmanuel Marty,
; Of course, LZSA compression algorithms are (c) 2019 Emmanuel Marty,
; see https://github.com/emmanuel-marty/lzsa for more information
;
; Drop me an email if you have any comments/ideas/suggestions: zxintrospec@gmail.com
@ -49,37 +50,38 @@
; DEFINE BACKWARD_DECOMPRESS
IFDEF BACKWARD_DECOMPRESS
MACRO NEXT_HL
dec hl
ENDM
MACRO ADD_OFFSET
or a : sbc hl,de
ENDM
MACRO BLOCKCOPY
lddr
ENDM
ELSE
IFNDEF BACKWARD_DECOMPRESS
MACRO NEXT_HL
inc hl
ENDM
MACRO ADD_OFFSET
add hl,de
ex de,hl : add hl,de
ENDM
MACRO BLOCKCOPY
ldir
ENDM
ELSE
MACRO NEXT_HL
dec hl
ENDM
MACRO ADD_OFFSET
ex de,hl : ld a,e : sub l : ld l,a
ld a,d : sbc h : ld h,a ; 4*4+3*4 = 28t / 7 bytes
ENDM
MACRO BLOCKCOPY
lddr
ENDM
ENDIF
@DecompressLZSA:
@DecompressLZSA1:
ld b,0 : jr ReadToken
NoLiterals: xor (hl) : NEXT_HL
@ -90,8 +92,8 @@ ShortOffset: ld d,#FF : add 3 : cp 15+3 : jr nc,LongerMatch
; placed here this saves a JP per iteration
CopyMatch: ld c,a
.UseC ex (sp),hl : push hl ; BC = len, DE = offset, HL = dest, SP ->[dest,src]
ADD_OFFSET : pop de ; BC = len, DE = dest, HL = dest-offset, SP->[src]
.UseC ex (sp),hl ; BC = len, DE = offset, HL = dest, SP ->[dest,src]
ADD_OFFSET ; BC = len, DE = dest, HL = dest-offset, SP->[src]
BLOCKCOPY : pop hl ; BC = 0, DE = dest, HL = src
ReadToken: ; first a byte token "O|LLL|MMMM" is read from the stream,

51
asm/z80/unlzsa1_small_v1.asm
View File

@ -1,5 +1,6 @@
;
; Size-optimized LZSA decompressor by spke (v.1 23/04/2019, 69 bytes)
; Size-optimized LZSA1 decompressor by spke (v.1 23/04/2019, 68 bytes);
; with improvements by uniabis (30/07/2019, -1 byte, +3% speed).
;
; The data must be compressed using the command line compressor by Emmanuel Marty
; The compression is done as follows:
@ -12,7 +13,7 @@
;
; ld hl,FirstByteOfCompressedData
; ld de,FirstByteOfMemoryForDecompressedData
; call DecompressLZSA
; call DecompressLZSA1
;
; Backward compression is also supported; you can compress files backward using:
;
@ -22,11 +23,11 @@
;
; ld hl,LastByteOfCompressedData
; ld de,LastByteOfMemoryForDecompressedData
; call DecompressLZSA
; call DecompressLZSA1
;
; (do not forget to uncomment the BACKWARD_DECOMPRESS option in the decompressor).
;
; Of course, LZSA compression algorithm is (c) 2019 Emmanuel Marty,
; Of course, LZSA compression algorithms are (c) 2019 Emmanuel Marty,
; see https://github.com/emmanuel-marty/lzsa for more information
;
; Drop me an email if you have any comments/ideas/suggestions: zxintrospec@gmail.com
@ -49,37 +50,37 @@
; DEFINE BACKWARD_DECOMPRESS
IFDEF BACKWARD_DECOMPRESS
MACRO NEXT_HL
dec hl
ENDM
MACRO ADD_OFFSET
or a : sbc hl,de
ENDM
MACRO BLOCKCOPY
lddr
ENDM
ELSE
IFNDEF BACKWARD_DECOMPRESS
MACRO NEXT_HL
inc hl
ENDM
MACRO ADD_OFFSET
add hl,de
ex de,hl : add hl,de
ENDM
MACRO BLOCKCOPY
ldir
ENDM
ELSE
MACRO NEXT_HL
dec hl
ENDM
MACRO ADD_OFFSET
push hl : or a : sbc hl,de : pop de ; 11+4+15+10 = 40t / 5 bytes
ENDM
MACRO BLOCKCOPY
lddr
ENDM
ENDIF
@DecompressLZSA:
@DecompressLZSA1:
ld b,0
; first a byte token "O|LLL|MMMM" is read from the stream,
@ -106,10 +107,10 @@ ShortOffset: and #0F : add 3 ; MMMM<15 means match lengths 0+3..14+3
cp 15+3 : call z,ReadLongBA ; MMMM=15 means lengths 14+3+
ld c,a
ex (sp),hl : push hl ; BC = len, DE = -offset, HL = dest, SP ->[dest,src]
ADD_OFFSET : pop de ; BC = len, DE = dest, HL = dest+(-offset), SP->[src]
BLOCKCOPY : pop hl ; BC = 0, DE = dest, HL = src
jr ReadToken
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 : jr ReadToken ; HL = src
; a standard routine to read extended codes
; into registers B (higher byte) and A (lower byte).