| 1 | /* Bra86.c -- Converter for x86 code (BCJ)\r |
| 2 | 2013-11-12 : Igor Pavlov : Public domain */\r |
| 3 | \r |
| 4 | #include "Precomp.h"\r |
| 5 | \r |
| 6 | #include "Bra.h"\r |
| 7 | \r |
| 8 | #define Test86MSByte(b) ((((b) + 1) & 0xFE) == 0)\r |
| 9 | \r |
| 10 | SizeT x86_Convert(Byte *data, SizeT size, UInt32 ip, UInt32 *state, int encoding)\r |
| 11 | {\r |
| 12 | SizeT pos = 0;\r |
| 13 | UInt32 mask = *state & 7;\r |
| 14 | if (size < 5)\r |
| 15 | return 0;\r |
| 16 | size -= 4;\r |
| 17 | ip += 5;\r |
| 18 | \r |
| 19 | for (;;)\r |
| 20 | {\r |
| 21 | Byte *p = data + pos;\r |
| 22 | const Byte *limit = data + size;\r |
| 23 | for (; p < limit; p++)\r |
| 24 | if ((*p & 0xFE) == 0xE8)\r |
| 25 | break;\r |
| 26 | \r |
| 27 | {\r |
| 28 | SizeT d = (SizeT)(p - data - pos);\r |
| 29 | pos = (SizeT)(p - data);\r |
| 30 | if (p >= limit)\r |
| 31 | {\r |
| 32 | *state = (d > 2 ? 0 : mask >> (unsigned)d);\r |
| 33 | return pos;\r |
| 34 | }\r |
| 35 | if (d > 2)\r |
| 36 | mask = 0;\r |
| 37 | else\r |
| 38 | {\r |
| 39 | mask >>= (unsigned)d;\r |
| 40 | if (mask != 0 && (mask > 4 || mask == 3 || Test86MSByte(p[(mask >> 1) + 1])))\r |
| 41 | {\r |
| 42 | mask = (mask >> 1) | 4;\r |
| 43 | pos++;\r |
| 44 | continue;\r |
| 45 | }\r |
| 46 | }\r |
| 47 | }\r |
| 48 | \r |
| 49 | if (Test86MSByte(p[4]))\r |
| 50 | {\r |
| 51 | UInt32 v = ((UInt32)p[4] << 24) | ((UInt32)p[3] << 16) | ((UInt32)p[2] << 8) | ((UInt32)p[1]);\r |
| 52 | UInt32 cur = ip + (UInt32)pos;\r |
| 53 | pos += 5;\r |
| 54 | if (encoding)\r |
| 55 | v += cur;\r |
| 56 | else\r |
| 57 | v -= cur;\r |
| 58 | if (mask != 0)\r |
| 59 | {\r |
| 60 | unsigned sh = (mask & 6) << 2;\r |
| 61 | if (Test86MSByte((Byte)(v >> sh)))\r |
| 62 | {\r |
| 63 | v ^= (((UInt32)0x100 << sh) - 1);\r |
| 64 | if (encoding)\r |
| 65 | v += cur;\r |
| 66 | else\r |
| 67 | v -= cur;\r |
| 68 | }\r |
| 69 | mask = 0;\r |
| 70 | }\r |
| 71 | p[1] = (Byte)v;\r |
| 72 | p[2] = (Byte)(v >> 8);\r |
| 73 | p[3] = (Byte)(v >> 16);\r |
| 74 | p[4] = (Byte)(0 - ((v >> 24) & 1));\r |
| 75 | }\r |
| 76 | else\r |
| 77 | {\r |
| 78 | mask = (mask >> 1) | 4;\r |
| 79 | pos++;\r |
| 80 | }\r |
| 81 | }\r |
| 82 | }\r |