physfs/src/lzma/C/Compress/Branch/BranchX86_2.c

136 lines
3.3 KiB
C

// BranchX86_2.c
#include "BranchX86_2.h"
#include "../../Alloc.h"
#ifdef _LZMA_PROB32
#define CProb UInt32
#else
#define CProb UInt16
#endif
#define IsJcc(b0, b1) ((b0) == 0x0F && ((b1) & 0xF0) == 0x80)
#define IsJ(b0, b1) ((b1 & 0xFE) == 0xE8 || IsJcc(b0, b1))
#define kNumTopBits 24
#define kTopValue ((UInt32)1 << kNumTopBits)
#define kNumBitModelTotalBits 11
#define kBitModelTotal (1 << kNumBitModelTotalBits)
#define kNumMoveBits 5
#define RC_READ_BYTE (*Buffer++)
#define RC_INIT2 Code = 0; Range = 0xFFFFFFFF; \
{ int i; for(i = 0; i < 5; i++) { RC_TEST; Code = (Code << 8) | RC_READ_BYTE; }}
#define RC_TEST { if (Buffer == BufferLim) return BCJ2_RESULT_DATA_ERROR; }
#define RC_INIT(buffer, bufferSize) Buffer = buffer; BufferLim = buffer + bufferSize; RC_INIT2
#define RC_NORMALIZE if (Range < kTopValue) { RC_TEST; Range <<= 8; Code = (Code << 8) | RC_READ_BYTE; }
#define IfBit0(p) RC_NORMALIZE; bound = (Range >> kNumBitModelTotalBits) * *(p); if (Code < bound)
#define UpdateBit0(p) Range = bound; *(p) += (kBitModelTotal - *(p)) >> kNumMoveBits;
#define UpdateBit1(p) Range -= bound; Code -= bound; *(p) -= (*(p)) >> kNumMoveBits;
// #define UpdateBit0(p) Range = bound; *(p) = (CProb)(*(p) + ((kBitModelTotal - *(p)) >> kNumMoveBits));
// #define UpdateBit1(p) Range -= bound; Code -= bound; *(p) = (CProb)(*(p) - (*(p) >> kNumMoveBits));
int x86_2_Decode(
const Byte *buf0, SizeT size0,
const Byte *buf1, SizeT size1,
const Byte *buf2, SizeT size2,
const Byte *buf3, SizeT size3,
Byte *outBuf, SizeT outSize)
{
CProb p[256 + 2];
SizeT inPos = 0, outPos = 0;
const Byte *Buffer, *BufferLim;
UInt32 Range, Code;
Byte prevByte = 0;
unsigned int i;
for (i = 0; i < sizeof(p) / sizeof(p[0]); i++)
p[i] = kBitModelTotal >> 1;
RC_INIT(buf3, size3);
if (outSize == 0)
return BCJ2_RESULT_OK;
for (;;)
{
Byte b;
CProb *prob;
UInt32 bound;
SizeT limit = size0 - inPos;
if (outSize - outPos < limit)
limit = outSize - outPos;
while (limit != 0)
{
Byte b = buf0[inPos];
outBuf[outPos++] = b;
if (IsJ(prevByte, b))
break;
inPos++;
prevByte = b;
limit--;
}
if (limit == 0 || outPos == outSize)
break;
b = buf0[inPos++];
if (b == 0xE8)
prob = p + prevByte;
else if (b == 0xE9)
prob = p + 256;
else
prob = p + 257;
IfBit0(prob)
{
UpdateBit0(prob)
prevByte = b;
}
else
{
UInt32 dest;
const Byte *v;
UpdateBit1(prob)
if (b == 0xE8)
{
v = buf1;
if (size1 < 4)
return BCJ2_RESULT_DATA_ERROR;
buf1 += 4;
size1 -= 4;
}
else
{
v = buf2;
if (size2 < 4)
return BCJ2_RESULT_DATA_ERROR;
buf2 += 4;
size2 -= 4;
}
dest = (((UInt32)v[0] << 24) | ((UInt32)v[1] << 16) |
((UInt32)v[2] << 8) | ((UInt32)v[3])) - ((UInt32)outPos + 4);
outBuf[outPos++] = (Byte)dest;
if (outPos == outSize)
break;
outBuf[outPos++] = (Byte)(dest >> 8);
if (outPos == outSize)
break;
outBuf[outPos++] = (Byte)(dest >> 16);
if (outPos == outSize)
break;
outBuf[outPos++] = prevByte = (Byte)(dest >> 24);
}
}
return (outPos == outSize) ? BCJ2_RESULT_OK : BCJ2_RESULT_DATA_ERROR;
}