diff options
Diffstat (limited to 'extern/lzma/Bcj2.c')
-rw-r--r-- | extern/lzma/Bcj2.c | 132 |
1 files changed, 132 insertions, 0 deletions
diff --git a/extern/lzma/Bcj2.c b/extern/lzma/Bcj2.c new file mode 100644 index 00000000000..20199ce5659 --- /dev/null +++ b/extern/lzma/Bcj2.c @@ -0,0 +1,132 @@ +/* Bcj2.c -- Converter for x86 code (BCJ2) +2008-10-04 : Igor Pavlov : Public domain */ + +#include "Bcj2.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_TEST { if (buffer == bufferLim) return SZ_ERROR_DATA; } +#define RC_INIT2 code = 0; range = 0xFFFFFFFF; \ + { int i; for (i = 0; i < 5; i++) { RC_TEST; code = (code << 8) | RC_READ_BYTE; }} + +#define NORMALIZE if (range < kTopValue) { RC_TEST; range <<= 8; code = (code << 8) | RC_READ_BYTE; } + +#define IF_BIT_0(p) ttt = *(p); bound = (range >> kNumBitModelTotalBits) * ttt; if (code < bound) +#define UPDATE_0(p) range = bound; *(p) = (CProb)(ttt + ((kBitModelTotal - ttt) >> kNumMoveBits)); NORMALIZE; +#define UPDATE_1(p) range -= bound; code -= bound; *(p) = (CProb)(ttt - (ttt >> kNumMoveBits)); NORMALIZE; + +int Bcj2_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; + + buffer = buf3; + bufferLim = buffer + size3; + RC_INIT2 + + if (outSize == 0) + return SZ_OK; + + for (;;) + { + Byte b; + CProb *prob; + UInt32 bound; + UInt32 ttt; + + 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; + + IF_BIT_0(prob) + { + UPDATE_0(prob) + prevByte = b; + } + else + { + UInt32 dest; + const Byte *v; + UPDATE_1(prob) + if (b == 0xE8) + { + v = buf1; + if (size1 < 4) + return SZ_ERROR_DATA; + buf1 += 4; + size1 -= 4; + } + else + { + v = buf2; + if (size2 < 4) + return SZ_ERROR_DATA; + 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) ? SZ_OK : SZ_ERROR_DATA; +} |