1 //===- BitCodes.h - Enum values for the bitcode format ----------*- C++ -*-===//
3 // The LLVM Compiler Infrastructure
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
8 //===----------------------------------------------------------------------===//
10 // This header Bitcode enum values.
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
16 //===----------------------------------------------------------------------===//
18 #ifndef LLVM_BITCODE_BITCODES_H
19 #define LLVM_BITCODE_BITCODES_H
21 #include "llvm/ADT/SmallVector.h"
22 #include "llvm/System/DataTypes.h"
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.
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.
36 END_BLOCK = 0, // Must be zero to guarantee termination for broken bitcode.
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.
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.
50 // This is not a code, this is a marker for the first abbrev assignment.
51 FIRST_APPLICATION_ABBREV = 4
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
60 BLOCKINFO_BLOCK_ID = 0,
62 // Block IDs 1-7 are reserved for future expansion.
63 FIRST_APPLICATION_BLOCKID = 8
66 /// BlockInfoCodes - The blockinfo block contains metadata about user-defined
69 // DEFINE_ABBREV has magic semantics here, applying to the current SETBID'd
70 // block, instead of the BlockInfo block.
72 BLOCKINFO_CODE_SETBID = 1, // SETBID: [blockid#]
73 BLOCKINFO_CODE_BLOCKNAME = 2, // BLOCKNAME: [name]
74 BLOCKINFO_CODE_SETRECORDNAME = 3 // BLOCKINFO_CODE_SETRECORDNAME: [id, name]
77 } // End bitc namespace
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").
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.
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.
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) {}
101 bool isLiteral() const { return IsLiteral; }
102 bool isEncoding() const { return !IsLiteral; }
104 // Accessors for literals.
105 uint64_t getLiteralValue() const { assert(isLiteral()); return Val; }
107 // Accessors for encoding info.
108 Encoding getEncoding() const { assert(isEncoding()); return (Encoding)Enc; }
109 uint64_t getEncodingData() const {
110 assert(isEncoding() && hasEncodingData());
114 bool hasEncodingData() const { return hasEncodingData(getEncoding()); }
115 static bool hasEncodingData(Encoding E) {
117 default: assert(0 && "Unknown encoding");
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;
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!");
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!");
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.
167 BitCodeAbbrev() : RefCount(1) {}
169 void addRef() { ++RefCount; }
170 void dropRef() { if (--RefCount == 0) delete this; }
172 unsigned getNumOperandInfos() const {
173 return static_cast<unsigned>(OperandList.size());
175 const BitCodeAbbrevOp &getOperandInfo(unsigned N) const {
176 return OperandList[N];
179 void Add(const BitCodeAbbrevOp &OpInfo) {
180 OperandList.push_back(OpInfo);
183 } // End llvm namespace