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134 lines
3.1 KiB
134 lines
3.1 KiB
/* Bcj2.c -- Converter for x86 code (BCJ2) |
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2008-10-04 : Igor Pavlov : Public domain */ |
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#include "Precomp.h" |
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#include "Bcj2.h" |
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#ifdef _LZMA_PROB32 |
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#define CProb UInt32 |
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#else |
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#define CProb UInt16 |
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#endif |
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#define IsJcc(b0, b1) ((b0) == 0x0F && ((b1) & 0xF0) == 0x80) |
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#define IsJ(b0, b1) ((b1 & 0xFE) == 0xE8 || IsJcc(b0, b1)) |
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#define kNumTopBits 24 |
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#define kTopValue ((UInt32)1 << kNumTopBits) |
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#define kNumBitModelTotalBits 11 |
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#define kBitModelTotal (1 << kNumBitModelTotalBits) |
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#define kNumMoveBits 5 |
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#define RC_READ_BYTE (*buffer++) |
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#define RC_TEST { if (buffer == bufferLim) return SZ_ERROR_DATA; } |
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#define RC_INIT2 code = 0; range = 0xFFFFFFFF; \ |
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{ int i; for (i = 0; i < 5; i++) { RC_TEST; code = (code << 8) | RC_READ_BYTE; }} |
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#define NORMALIZE if (range < kTopValue) { RC_TEST; range <<= 8; code = (code << 8) | RC_READ_BYTE; } |
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#define IF_BIT_0(p) ttt = *(p); bound = (range >> kNumBitModelTotalBits) * ttt; if (code < bound) |
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#define UPDATE_0(p) range = bound; *(p) = (CProb)(ttt + ((kBitModelTotal - ttt) >> kNumMoveBits)); NORMALIZE; |
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#define UPDATE_1(p) range -= bound; code -= bound; *(p) = (CProb)(ttt - (ttt >> kNumMoveBits)); NORMALIZE; |
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int Bcj2_Decode( |
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const Byte *buf0, SizeT size0, |
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const Byte *buf1, SizeT size1, |
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const Byte *buf2, SizeT size2, |
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const Byte *buf3, SizeT size3, |
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Byte *outBuf, SizeT outSize) |
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{ |
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CProb p[256 + 2]; |
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SizeT inPos = 0, outPos = 0; |
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const Byte *buffer, *bufferLim; |
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UInt32 range, code; |
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Byte prevByte = 0; |
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unsigned int i; |
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for (i = 0; i < sizeof(p) / sizeof(p[0]); i++) |
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p[i] = kBitModelTotal >> 1; |
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buffer = buf3; |
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bufferLim = buffer + size3; |
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RC_INIT2 |
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if (outSize == 0) |
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return SZ_OK; |
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for (;;) |
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{ |
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Byte b; |
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CProb *prob; |
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UInt32 bound; |
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UInt32 ttt; |
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SizeT limit = size0 - inPos; |
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if (outSize - outPos < limit) |
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limit = outSize - outPos; |
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while (limit != 0) |
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{ |
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Byte b = buf0[inPos]; |
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outBuf[outPos++] = b; |
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if (IsJ(prevByte, b)) |
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break; |
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inPos++; |
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prevByte = b; |
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limit--; |
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} |
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if (limit == 0 || outPos == outSize) |
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break; |
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b = buf0[inPos++]; |
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if (b == 0xE8) |
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prob = p + prevByte; |
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else if (b == 0xE9) |
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prob = p + 256; |
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else |
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prob = p + 257; |
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IF_BIT_0(prob) |
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{ |
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UPDATE_0(prob) |
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prevByte = b; |
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} |
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else |
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{ |
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UInt32 dest; |
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const Byte *v; |
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UPDATE_1(prob) |
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if (b == 0xE8) |
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{ |
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v = buf1; |
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if (size1 < 4) |
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return SZ_ERROR_DATA; |
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buf1 += 4; |
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size1 -= 4; |
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} |
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else |
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{ |
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v = buf2; |
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if (size2 < 4) |
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return SZ_ERROR_DATA; |
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buf2 += 4; |
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size2 -= 4; |
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} |
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dest = (((UInt32)v[0] << 24) | ((UInt32)v[1] << 16) | |
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((UInt32)v[2] << 8) | ((UInt32)v[3])) - ((UInt32)outPos + 4); |
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outBuf[outPos++] = (Byte)dest; |
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if (outPos == outSize) |
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break; |
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outBuf[outPos++] = (Byte)(dest >> 8); |
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if (outPos == outSize) |
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break; |
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outBuf[outPos++] = (Byte)(dest >> 16); |
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if (outPos == outSize) |
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break; |
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outBuf[outPos++] = prevByte = (Byte)(dest >> 24); |
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} |
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} |
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return (outPos == outSize) ? SZ_OK : SZ_ERROR_DATA; |
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}
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