kolibrios/programs/games/fara/trunk/lzma_unpack.asm

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NASM
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; Exports only one function:
; void __stdcall lzma_decompress(
; const void* source,
; void* destination,
; unsigned dest_length);
format COFF
section '.text' code
pb equ 2 ; pos state bits
lp equ 0 ; literal pos state bits
lc equ 3 ; literal context bits
posStateMask equ ((1 shl pb)-1)
literalPosMask equ ((1 shl lp)-1)
kNumPosBitsMax = 4
kNumPosStatesMax = (1 shl kNumPosBitsMax)
kLenNumLowBits = 3
kLenNumLowSymbols = (1 shl kLenNumLowBits)
kLenNumMidBits = 3
kLenNumMidSymbols = (1 shl kLenNumMidBits)
kLenNumHighBits = 8
kLenNumHighSymbols = (1 shl kLenNumHighBits)
LenChoice = 0
LenChoice2 = 1
LenLow = 2
LenMid = (LenLow + (kNumPosStatesMax shl kLenNumLowBits))
LenHigh = (LenMid + (kNumPosStatesMax shl kLenNumMidBits))
kNumLenProbs = (LenHigh + kLenNumHighSymbols)
kNumStates = 12
kNumLitStates = 7
kStartPosModelIndex = 4
kEndPosModelIndex = 14
kNumFullDistances = (1 shl (kEndPosModelIndex/2))
kNumPosSlotBits = 6
kNumLenToPosStates = 4
kNumAlignBits = 4
kAlignTableSize = (1 shl kNumAlignBits)
kMatchMinLen = 2
IsMatch = 0
IsRep = 0xC0 ; (IsMatch + (kNumStates shl kNumPosBitsMax))
IsRepG0 = 0xCC ; (IsRep + kNumStates)
IsRepG1 = 0xD8 ; (IsRepG0 + kNumStates)
IsRepG2 = 0xE4 ; (IsRepG1 + kNumStates)
IsRep0Long = 0xF0 ; (IsRepG2 + kNumStates)
PosSlot = 0x1B0 ; (IsRep0Long + (kNumStates shl kNumPosBitsMax))
SpecPos = 0x2B0 ; (PosSlot + (kNumLenToPosStates shl kNumPosSlotBits))
Align_ = 0x322 ; (SpecPos + kNumFullDistances - kEndPosModelIndex)
Lencoder = 0x332 ; (Align_ + kAlignTableSize)
RepLencoder = 0x534 ; (Lencoder + kNumLenProbs)
Literal = 0x736 ; (RepLencoder + kNumLenProbs)
LZMA_BASE_SIZE = 1846 ; must be ==Literal
LZMA_LIT_SIZE = 768
kNumTopBits = 24
kTopValue = (1 shl kNumTopBits)
kNumBitModelTotalBits = 11
kBitModelTotal = (1 shl kNumBitModelTotalBits)
kNumMoveBits = 5
RangeDecoderBitDecode:
; in: eax->prob
; out: CF=bit
push edx
mov edx, [range]
shr edx, kNumBitModelTotalBits
imul edx, [eax]
cmp [code_], edx
jae .ae
mov [range], edx
mov edx, kBitModelTotal
sub edx, [eax]
shr edx, kNumMoveBits
add [eax], edx
.n:
pushfd
call update_decoder
popfd
pop edx
ret
.ae:
sub [range], edx
sub [code_], edx
mov edx, [eax]
shr edx, kNumMoveBits
sub [eax], edx
stc
jmp .n
update_decoder:
cmp byte [range+3], 0 ;cmp dword [range], kTopValue
jnz @f ;jae @f
shl dword [range], 8
shl dword [code_], 8
push eax
mov eax, [inptr]
mov al, [eax]
inc dword [inptr]
mov byte [code_], al
pop eax
@@: ret
LzmaLenDecode:
; in: eax->prob, edx=posState
; out: ecx=len
; LenChoice==0
; add eax, LenChoice*4
call RangeDecoderBitDecode
jnc .0
add eax, (LenChoice2-LenChoice)*4
call RangeDecoderBitDecode
jc @f
mov cl, kLenNumMidBits
shl edx, cl
lea eax, [eax + (LenMid-LenChoice2)*4 + edx*4]
call RangeDecoderBitTreeDecode
add ecx, kLenNumLowSymbols
ret
@@:
add eax, (LenHigh-LenChoice2)*4
mov cl, kLenNumHighBits
call RangeDecoderBitTreeDecode
add ecx, kLenNumLowSymbols + kLenNumMidSymbols
ret
.0:
mov cl, kLenNumLowBits
shl edx, cl
lea eax, [eax + LenLow*4 + edx*4]
RangeDecoderBitTreeDecode:
; in: eax->probs,ecx=numLevels
; out: ecx=length; destroys edx
push edi
xor edx, edx
inc edx
mov edi, edx
xchg eax, edi
@@:
push eax
lea eax, [edi+edx*4]
call RangeDecoderBitDecode
pop eax
adc dl, dl
add al, al
loop @b
sub dl, al
pop edi
mov ecx, edx
ret
; void __stdcall lzma_decompress(
; const void* source,
; void* destination,
; unsigned dest_length);
lzma_decompress equ _lzma_decompress@12
public lzma_decompress
lzma_decompress:
push esi edi ebx ebp
mov esi, [esp+4*4+4] ; source
xor ebp, ebp
mov edi, code_
inc esi
lodsd
bswap eax
stosd
xor eax, eax
dec eax
stosd
stosd
stosd
stosd
xchg eax, esi
stosd
mov ecx, Literal + (LZMA_LIT_SIZE shl (lc+lp))
mov eax, kBitModelTotal/2
mov edi, p
rep stosd
mov edi, [esp+4*4+8] ; destination
mov ebx, edi
add ebx, [esp+4*4+12] ; dest_length
.main_loop:
cmp edi, ebx
jae .main_loop_done
mov edx, edi
and edx, posStateMask
push eax ; al = previous byte
mov eax, ebp
shl eax, kNumPosBitsMax+2
lea eax, [p + IsMatch*4 + eax + edx*4]
call RangeDecoderBitDecode
pop eax
jc .1
movzx eax, al
if literalPosMask
mov ah, dl
and ah, literalPosMask
end if
shr eax, 8-lc
imul eax, LZMA_LIT_SIZE*4
add eax, p+Literal*4
mov cl, 1
cmp ebp, kNumLitStates
jb .literal
mov dl, [edi + esi]
.lx0:
add dl, dl
setc ch
push eax
lea eax, [eax+ecx*4+0x100*4]
call RangeDecoderBitDecode
pop eax
adc cl, cl
jc .lx1
xor ch, cl
test ch, 1
mov ch, 0
jz .lx0
.literal:
@@:
push eax
lea eax, [eax+ecx*4]
call RangeDecoderBitDecode
pop eax
adc cl, cl
jnc @b
.lx1:
mov eax, ebp
cmp al, 4
jb @f
cmp al, 10
mov al, 3
jb @f
mov al, 6
@@: sub ebp, eax
xchg eax, ecx
.stosb_main_loop:
stosb
jmp .main_loop
.1:
lea eax, [p + IsRep*4 + ebp*4]
call RangeDecoderBitDecode
jnc .10
add eax, (IsRepG0 - IsRep)*4 ;lea eax, [p + IsRepG0*4 + ebp*4]
call RangeDecoderBitDecode
jc .111
mov eax, ebp
shl eax, kNumPosBitsMax+2
lea eax, [p + IsRep0Long*4 + eax + edx*4]
call RangeDecoderBitDecode
jc .1101
cmp ebp, 7
sbb ebp, ebp
lea ebp, [ebp+ebp+11]
mov al, [edi + esi]
jmp .stosb_main_loop
.111:
add eax, (IsRepG1 - IsRepG0) * 4 ;lea eax, [p + IsRepG1*4 + ebp*4]
call RangeDecoderBitDecode
xchg esi, [rep1]
jnc @f
add eax, (IsRepG2 - IsRepG1) * 4 ;lea eax, [p + IsRepG2*4 + ebp*4]
call RangeDecoderBitDecode
xchg esi, [rep2]
jnc @f
xchg esi, [rep3]
@@:
.1101:
mov eax, p + RepLencoder*4
call LzmaLenDecode
push 8
jmp .rmu
.10:
xchg esi, [rep1]
xchg esi, [rep2]
mov [rep3], esi
mov eax, p + Lencoder*4
call LzmaLenDecode
push kNumLenToPosStates-1
pop eax
cmp eax, ecx
jb @f
mov eax, ecx
@@:
push ecx
push kNumPosSlotBits
pop ecx
shl eax, cl
shl eax, 2
add eax, p+PosSlot*4
call RangeDecoderBitTreeDecode
mov esi, ecx
cmp ecx, kStartPosModelIndex
jb .l6
push ecx
xor eax, eax
inc eax
shr ecx, 1
adc al, al
dec ecx
shl eax, cl
mov esi, eax
pop edx
cmp edx, kEndPosModelIndex
jae .l5
sub eax, edx
shl eax, 2
add eax, p + (SpecPos - 1)*4
jmp .l59
.l5:
sub ecx, kNumAlignBits
; call RangeDecoderDecodeDirectBits
;RangeDecoderDecodeDirectBits:
xor eax, eax
.l:
shr dword [range], 1
add eax, eax
mov edx, [code_]
sub edx, [range]
jb @f
mov [code_], edx
inc eax
@@:
call update_decoder
loop .l
; ret
mov cl, kNumAlignBits
shl eax, cl
add esi, eax
mov eax, p+Align_*4
.l59:
; call RangeDecoderReverseBitTreeDecode_addesi
;_RangeDecoderReverseBitTreeDecode_addesi:
; in: eax->probs,ecx=numLevels
; out: esi+=length; destroys edx
push edi ecx
xor edx, edx
inc edx
xor edi, edi
@@:
push eax
lea eax, [eax+edx*4]
call RangeDecoderBitDecode
lahf
adc edx, edx
sahf
rcr edi, 1
pop eax
loop @b
pop ecx
rol edi, cl
add esi, edi
pop edi
; ret
.l6:
pop ecx
not esi
push 7
.rmu:
cmp ebp, 7
pop ebp
jb @f
inc ebp
inc ebp
inc ebp
@@:
.repmovsb:
inc ecx
push esi
add esi, edi
rep movsb
lodsb
pop esi
jmp .stosb_main_loop
.main_loop_done:
pop ebp ebx edi esi
ret 12
section '.bss' data
p rd LZMA_BASE_SIZE + (LZMA_LIT_SIZE shl (lc+lp))
code_ dd ?
range dd ?
rep1 dd ?
rep2 dd ?
rep3 dd ?
inptr dd ?
previousByte db ?