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Move instruction before branch to save one byte in 6809 LZSA2 depacker

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This commit is contained in:
Doug Masten 2020-06-26 16:48:58 -05:00
parent 56ba563794
commit f72133f4cf
1 changed files with 2 additions and 4 deletions
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6
asm/6809/unlzsa2.s
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@ -65,9 +65,9 @@ lz2nolt ldb ,s ; get token again, don't pop it from the stack
bcs lz2replg ; if token's X bit is set, rep or large offset
lslb ; push token's Y flag bit into carry
sex ; push token's Z flag bit into reg A (carry flag is not effected)
bcs lz2offs9 ; if token's Y bit is set, 9 bits offset
sex ; push token's Z flag bit into reg A
bsr lz2nibl ; get offset nibble in B
lsla ; retrieve token's Z flag bit and push into carry
@ -76,9 +76,7 @@ lz2nolt ldb ,s ; get token again, don't pop it from the stack
sex ; set bits 8-15 of offset to $FF
bra lz2gotof
lz2offs9 sex ; extend token's Z flag bit into reg A
deca ; set bits 9-15 of offset, reverse bit 8
lz2offs9 deca ; set bits 9-15 of offset, reverse bit 8
ldb ,x+ ; load low 8 bits of (negative, signed) offset
bra lz2gotof