llvm-6502/include/llvm/Bitcode/BitCodes.h
Craig Topper 50bee42b54 Convert assert(0) to llvm_unreachable
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@149849 91177308-0d34-0410-b5e6-96231b3b80d8
2012-02-05 22:14:15 +00:00

185 lines
6.4 KiB
C++

//===- BitCodes.h - Enum values for the bitcode format ----------*- C++ -*-===//
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
// This header Bitcode enum values.
//
// The enum values defined in this file should be considered permanent. If
// new features are added, they should have values added at the end of the
// respective lists.
//
//===----------------------------------------------------------------------===//
#ifndef LLVM_BITCODE_BITCODES_H
#define LLVM_BITCODE_BITCODES_H
#include "llvm/ADT/SmallVector.h"
#include "llvm/Support/DataTypes.h"
#include "llvm/Support/ErrorHandling.h"
#include <cassert>
namespace llvm {
namespace bitc {
enum StandardWidths {
BlockIDWidth = 8, // We use VBR-8 for block IDs.
CodeLenWidth = 4, // Codelen are VBR-4.
BlockSizeWidth = 32 // BlockSize up to 2^32 32-bit words = 16GB per block.
};
// The standard abbrev namespace always has a way to exit a block, enter a
// nested block, define abbrevs, and define an unabbreviated record.
enum FixedAbbrevIDs {
END_BLOCK = 0, // Must be zero to guarantee termination for broken bitcode.
ENTER_SUBBLOCK = 1,
/// DEFINE_ABBREV - Defines an abbrev for the current block. It consists
/// of a vbr5 for # operand infos. Each operand info is emitted with a
/// single bit to indicate if it is a literal encoding. If so, the value is
/// emitted with a vbr8. If not, the encoding is emitted as 3 bits followed
/// by the info value as a vbr5 if needed.
DEFINE_ABBREV = 2,
// UNABBREV_RECORDs are emitted with a vbr6 for the record code, followed by
// a vbr6 for the # operands, followed by vbr6's for each operand.
UNABBREV_RECORD = 3,
// This is not a code, this is a marker for the first abbrev assignment.
FIRST_APPLICATION_ABBREV = 4
};
/// StandardBlockIDs - All bitcode files can optionally include a BLOCKINFO
/// block, which contains metadata about other blocks in the file.
enum StandardBlockIDs {
/// BLOCKINFO_BLOCK is used to define metadata about blocks, for example,
/// standard abbrevs that should be available to all blocks of a specified
/// ID.
BLOCKINFO_BLOCK_ID = 0,
// Block IDs 1-7 are reserved for future expansion.
FIRST_APPLICATION_BLOCKID = 8
};
/// BlockInfoCodes - The blockinfo block contains metadata about user-defined
/// blocks.
enum BlockInfoCodes {
// DEFINE_ABBREV has magic semantics here, applying to the current SETBID'd
// block, instead of the BlockInfo block.
BLOCKINFO_CODE_SETBID = 1, // SETBID: [blockid#]
BLOCKINFO_CODE_BLOCKNAME = 2, // BLOCKNAME: [name]
BLOCKINFO_CODE_SETRECORDNAME = 3 // BLOCKINFO_CODE_SETRECORDNAME: [id, name]
};
} // End bitc namespace
/// BitCodeAbbrevOp - This describes one or more operands in an abbreviation.
/// This is actually a union of two different things:
/// 1. It could be a literal integer value ("the operand is always 17").
/// 2. It could be an encoding specification ("this operand encoded like so").
///
class BitCodeAbbrevOp {
uint64_t Val; // A literal value or data for an encoding.
bool IsLiteral : 1; // Indicate whether this is a literal value or not.
unsigned Enc : 3; // The encoding to use.
public:
enum Encoding {
Fixed = 1, // A fixed width field, Val specifies number of bits.
VBR = 2, // A VBR field where Val specifies the width of each chunk.
Array = 3, // A sequence of fields, next field species elt encoding.
Char6 = 4, // A 6-bit fixed field which maps to [a-zA-Z0-9._].
Blob = 5 // 32-bit aligned array of 8-bit characters.
};
explicit BitCodeAbbrevOp(uint64_t V) : Val(V), IsLiteral(true) {}
explicit BitCodeAbbrevOp(Encoding E, uint64_t Data = 0)
: Val(Data), IsLiteral(false), Enc(E) {}
bool isLiteral() const { return IsLiteral; }
bool isEncoding() const { return !IsLiteral; }
// Accessors for literals.
uint64_t getLiteralValue() const { assert(isLiteral()); return Val; }
// Accessors for encoding info.
Encoding getEncoding() const { assert(isEncoding()); return (Encoding)Enc; }
uint64_t getEncodingData() const {
assert(isEncoding() && hasEncodingData());
return Val;
}
bool hasEncodingData() const { return hasEncodingData(getEncoding()); }
static bool hasEncodingData(Encoding E) {
switch (E) {
case Fixed:
case VBR:
return true;
case Array:
case Char6:
case Blob:
return false;
}
llvm_unreachable("Invalid encoding");
}
/// isChar6 - Return true if this character is legal in the Char6 encoding.
static bool isChar6(char C) {
if (C >= 'a' && C <= 'z') return true;
if (C >= 'A' && C <= 'Z') return true;
if (C >= '0' && C <= '9') return true;
if (C == '.' || C == '_') return true;
return false;
}
static unsigned EncodeChar6(char C) {
if (C >= 'a' && C <= 'z') return C-'a';
if (C >= 'A' && C <= 'Z') return C-'A'+26;
if (C >= '0' && C <= '9') return C-'0'+26+26;
if (C == '.') return 62;
if (C == '_') return 63;
llvm_unreachable("Not a value Char6 character!");
}
static char DecodeChar6(unsigned V) {
assert((V & ~63) == 0 && "Not a Char6 encoded character!");
if (V < 26) return V+'a';
if (V < 26+26) return V-26+'A';
if (V < 26+26+10) return V-26-26+'0';
if (V == 62) return '.';
if (V == 63) return '_';
llvm_unreachable("Not a value Char6 character!");
}
};
/// BitCodeAbbrev - This class represents an abbreviation record. An
/// abbreviation allows a complex record that has redundancy to be stored in a
/// specialized format instead of the fully-general, fully-vbr, format.
class BitCodeAbbrev {
SmallVector<BitCodeAbbrevOp, 8> OperandList;
unsigned char RefCount; // Number of things using this.
~BitCodeAbbrev() {}
public:
BitCodeAbbrev() : RefCount(1) {}
void addRef() { ++RefCount; }
void dropRef() { if (--RefCount == 0) delete this; }
unsigned getNumOperandInfos() const {
return static_cast<unsigned>(OperandList.size());
}
const BitCodeAbbrevOp &getOperandInfo(unsigned N) const {
return OperandList[N];
}
void Add(const BitCodeAbbrevOp &OpInfo) {
OperandList.push_back(OpInfo);
}
};
} // End llvm namespace
#endif