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-2 bytes for 6809 LZSA1 depacker, slightly faster

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Emmanuel Marty 2020-06-19 20:07:41 +02:00 committed by GitHub
parent f198431a71
commit 2cdeda4784
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GPG Key ID: 4AEE18F83AFDEB23
1 changed files with 3 additions and 3 deletions
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asm/6809/unlzsa1.s
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@ -1,4 +1,4 @@
; unlzsa1.s - 6809 decompression routine for raw LZSA1 - 119 bytes ; unlzsa1.s - 6809 decompression routine for raw LZSA1 - 117 bytes
; compress with lzsa -r <original_file> <compressed_file> ; compress with lzsa -r <original_file> <compressed_file>
; ;
; in: x = start of compressed data ; in: x = start of compressed data
@ -27,7 +27,7 @@ decompress_lzsa1
lz1token ldb ,x+ ; load next token into B: O|LLL|MMMM lz1token ldb ,x+ ; load next token into B: O|LLL|MMMM
pshs b ; save it pshs b ; save it
lda #$00 ; clear A (high part of literals count) clra ; clear A (high part of literals count)
andb #$70 ; isolate LLL (embedded literals count) in B andb #$70 ; isolate LLL (embedded literals count) in B
beq lz1nolt ; skip if no literals beq lz1nolt ; skip if no literals
cmpb #$70 ; LITERALS_RUN_LEN? cmpb #$70 ; LITERALS_RUN_LEN?
@ -74,7 +74,7 @@ lz1gotof leau d,y ; put backreference start address in U (dst+offset)
puls b ; restore token puls b ; restore token
lda #$00 ; clear A (high part of match length) clra ; clear A (high part of match length)
andb #$0F ; isolate MMMM (embedded match length) andb #$0F ; isolate MMMM (embedded match length)
addb #$03 ; add MIN_MATCH_SIZE addb #$03 ; add MIN_MATCH_SIZE
cmpb #$12 ; MATCH_RUN_LEN? cmpb #$12 ; MATCH_RUN_LEN?