1 //===- BitCodes.h - Enum values for the bitcode format ----------*- C++ -*-===// 2 // 3 // The LLVM Compiler Infrastructure 4 // 5 // This file is distributed under the University of Illinois Open Source 6 // License. See LICENSE.TXT for details. 7 // 8 //===----------------------------------------------------------------------===// 9 // 10 // This header Bitcode enum values. 11 // 12 // The enum values defined in this file should be considered permanent. If 13 // new features are added, they should have values added at the end of the 14 // respective lists. 15 // 16 //===----------------------------------------------------------------------===// 17 18 #ifndef LLVM_BITCODE_BITCODES_H 19 #define LLVM_BITCODE_BITCODES_H 20 21 #include "llvm/ADT/SmallVector.h" 22 #include "llvm/Support/DataTypes.h" 23 #include <cassert> 24 25 namespace llvm { 26 namespace bitc { 27 enum StandardWidths { 28 BlockIDWidth = 8, // We use VBR-8 for block IDs. 29 CodeLenWidth = 4, // Codelen are VBR-4. 30 BlockSizeWidth = 32 // BlockSize up to 2^32 32-bit words = 16GB per block. 31 }; 32 33 // The standard abbrev namespace always has a way to exit a block, enter a 34 // nested block, define abbrevs, and define an unabbreviated record. 35 enum FixedAbbrevIDs { 36 END_BLOCK = 0, // Must be zero to guarantee termination for broken bitcode. 37 ENTER_SUBBLOCK = 1, 38 39 /// DEFINE_ABBREV - Defines an abbrev for the current block. It consists 40 /// of a vbr5 for # operand infos. Each operand info is emitted with a 41 /// single bit to indicate if it is a literal encoding. If so, the value is 42 /// emitted with a vbr8. If not, the encoding is emitted as 3 bits followed 43 /// by the info value as a vbr5 if needed. 44 DEFINE_ABBREV = 2, 45 46 // UNABBREV_RECORDs are emitted with a vbr6 for the record code, followed by 47 // a vbr6 for the # operands, followed by vbr6's for each operand. 48 UNABBREV_RECORD = 3, 49 50 // This is not a code, this is a marker for the first abbrev assignment. 51 FIRST_APPLICATION_ABBREV = 4 52 }; 53 54 /// StandardBlockIDs - All bitcode files can optionally include a BLOCKINFO 55 /// block, which contains metadata about other blocks in the file. 56 enum StandardBlockIDs { 57 /// BLOCKINFO_BLOCK is used to define metadata about blocks, for example, 58 /// standard abbrevs that should be available to all blocks of a specified 59 /// ID. 60 BLOCKINFO_BLOCK_ID = 0, 61 62 // Block IDs 1-7 are reserved for future expansion. 63 FIRST_APPLICATION_BLOCKID = 8 64 }; 65 66 /// BlockInfoCodes - The blockinfo block contains metadata about user-defined 67 /// blocks. 68 enum BlockInfoCodes { 69 // DEFINE_ABBREV has magic semantics here, applying to the current SETBID'd 70 // block, instead of the BlockInfo block. 71 72 BLOCKINFO_CODE_SETBID = 1, // SETBID: [blockid#] 73 BLOCKINFO_CODE_BLOCKNAME = 2, // BLOCKNAME: [name] 74 BLOCKINFO_CODE_SETRECORDNAME = 3 // BLOCKINFO_CODE_SETRECORDNAME: [id, name] 75 }; 76 77 } // End bitc namespace 78 79 /// BitCodeAbbrevOp - This describes one or more operands in an abbreviation. 80 /// This is actually a union of two different things: 81 /// 1. It could be a literal integer value ("the operand is always 17"). 82 /// 2. It could be an encoding specification ("this operand encoded like so"). 83 /// 84 class BitCodeAbbrevOp { 85 uint64_t Val; // A literal value or data for an encoding. 86 bool IsLiteral : 1; // Indicate whether this is a literal value or not. 87 unsigned Enc : 3; // The encoding to use. 88 public: 89 enum Encoding { 90 Fixed = 1, // A fixed width field, Val specifies number of bits. 91 VBR = 2, // A VBR field where Val specifies the width of each chunk. 92 Array = 3, // A sequence of fields, next field species elt encoding. 93 Char6 = 4, // A 6-bit fixed field which maps to [a-zA-Z0-9._]. 94 Blob = 5 // 32-bit aligned array of 8-bit characters. 95 }; 96 97 explicit BitCodeAbbrevOp(uint64_t V) : Val(V), IsLiteral(true) {} 98 explicit BitCodeAbbrevOp(Encoding E, uint64_t Data = 0) 99 : Val(Data), IsLiteral(false), Enc(E) {} 100 101 bool isLiteral() const { return IsLiteral; } 102 bool isEncoding() const { return !IsLiteral; } 103 104 // Accessors for literals. 105 uint64_t getLiteralValue() const { assert(isLiteral()); return Val; } 106 107 // Accessors for encoding info. 108 Encoding getEncoding() const { assert(isEncoding()); return (Encoding)Enc; } 109 uint64_t getEncodingData() const { 110 assert(isEncoding() && hasEncodingData()); 111 return Val; 112 } 113 114 bool hasEncodingData() const { return hasEncodingData(getEncoding()); } 115 static bool hasEncodingData(Encoding E) { 116 switch (E) { 117 default: assert(0 && "Unknown encoding"); 118 case Fixed: 119 case VBR: 120 return true; 121 case Array: 122 case Char6: 123 case Blob: 124 return false; 125 } 126 } 127 128 /// isChar6 - Return true if this character is legal in the Char6 encoding. 129 static bool isChar6(char C) { 130 if (C >= 'a' && C <= 'z') return true; 131 if (C >= 'A' && C <= 'Z') return true; 132 if (C >= '0' && C <= '9') return true; 133 if (C == '.' || C == '_') return true; 134 return false; 135 } 136 static unsigned EncodeChar6(char C) { 137 if (C >= 'a' && C <= 'z') return C-'a'; 138 if (C >= 'A' && C <= 'Z') return C-'A'+26; 139 if (C >= '0' && C <= '9') return C-'0'+26+26; 140 if (C == '.') return 62; 141 if (C == '_') return 63; 142 assert(0 && "Not a value Char6 character!"); 143 return 0; 144 } 145 146 static char DecodeChar6(unsigned V) { 147 assert((V & ~63) == 0 && "Not a Char6 encoded character!"); 148 if (V < 26) return V+'a'; 149 if (V < 26+26) return V-26+'A'; 150 if (V < 26+26+10) return V-26-26+'0'; 151 if (V == 62) return '.'; 152 if (V == 63) return '_'; 153 assert(0 && "Not a value Char6 character!"); 154 return ' '; 155 } 156 157 }; 158 159 /// BitCodeAbbrev - This class represents an abbreviation record. An 160 /// abbreviation allows a complex record that has redundancy to be stored in a 161 /// specialized format instead of the fully-general, fully-vbr, format. 162 class BitCodeAbbrev { 163 SmallVector<BitCodeAbbrevOp, 8> OperandList; 164 unsigned char RefCount; // Number of things using this. 165 ~BitCodeAbbrev() {} 166 public: 167 BitCodeAbbrev() : RefCount(1) {} 168 169 void addRef() { ++RefCount; } 170 void dropRef() { if (--RefCount == 0) delete this; } 171 172 unsigned getNumOperandInfos() const { 173 return static_cast<unsigned>(OperandList.size()); 174 } 175 const BitCodeAbbrevOp &getOperandInfo(unsigned N) const { 176 return OperandList[N]; 177 } 178 179 void Add(const BitCodeAbbrevOp &OpInfo) { 180 OperandList.push_back(OpInfo); 181 } 182 }; 183 } // End llvm namespace 184 185 #endif 186
