llvm-6502/include/llvm/Target/TargetInstrInfo.h
2004-07-27 21:43:38 +00:00

249 lines
8.3 KiB
C++

//===-- llvm/Target/TargetInstrInfo.h - Instruction Info --------*- C++ -*-===//
//
// The LLVM Compiler Infrastructure
//
// This file was developed by the LLVM research group and is distributed under
// the University of Illinois Open Source License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
// This file describes the target machine instructions to the code generator.
//
//===----------------------------------------------------------------------===//
#ifndef LLVM_TARGET_TARGETINSTRINFO_H
#define LLVM_TARGET_TARGETINSTRINFO_H
#include "Support/DataTypes.h"
#include <vector>
#include <cassert>
namespace llvm {
class MachineInstr;
class TargetMachine;
class Value;
class Type;
class Instruction;
class Constant;
class Function;
class MachineCodeForInstruction;
//---------------------------------------------------------------------------
// Data types used to define information about a single machine instruction
//---------------------------------------------------------------------------
typedef short MachineOpCode;
typedef unsigned InstrSchedClass;
//---------------------------------------------------------------------------
// struct TargetInstrDescriptor:
// Predefined information about each machine instruction.
// Designed to initialized statically.
//
const unsigned M_NOP_FLAG = 1 << 0;
const unsigned M_BRANCH_FLAG = 1 << 1;
const unsigned M_CALL_FLAG = 1 << 2;
const unsigned M_RET_FLAG = 1 << 3;
const unsigned M_CC_FLAG = 1 << 6;
const unsigned M_LOAD_FLAG = 1 << 10;
const unsigned M_STORE_FLAG = 1 << 12;
const unsigned M_DUMMY_PHI_FLAG = 1 << 13;
const unsigned M_PSEUDO_FLAG = 1 << 14; // Pseudo instruction
// 3-addr instructions which really work like 2-addr ones, eg. X86 add/sub
const unsigned M_2_ADDR_FLAG = 1 << 15;
// M_TERMINATOR_FLAG - Is this instruction part of the terminator for a basic
// block? Typically this is things like return and branch instructions.
// Various passes use this to insert code into the bottom of a basic block, but
// before control flow occurs.
const unsigned M_TERMINATOR_FLAG = 1 << 16;
struct TargetInstrDescriptor {
const char * Name; // Assembly language mnemonic for the opcode.
int numOperands; // Number of args; -1 if variable #args
int resultPos; // Position of the result; -1 if no result
unsigned maxImmedConst; // Largest +ve constant in IMMED field or 0.
bool immedIsSignExtended; // Is IMMED field sign-extended? If so,
// smallest -ve value is -(maxImmedConst+1).
unsigned numDelaySlots; // Number of delay slots after instruction
unsigned latency; // Latency in machine cycles
InstrSchedClass schedClass; // enum identifying instr sched class
unsigned Flags; // flags identifying machine instr class
unsigned TSFlags; // Target Specific Flag values
const unsigned *ImplicitUses; // Registers implicitly read by this instr
const unsigned *ImplicitDefs; // Registers implicitly defined by this instr
};
//---------------------------------------------------------------------------
///
/// TargetInstrInfo - Interface to description of machine instructions
///
class TargetInstrInfo {
const TargetInstrDescriptor* desc; // raw array to allow static init'n
unsigned NumOpcodes; // number of entries in the desc array
unsigned numRealOpCodes; // number of non-dummy op codes
TargetInstrInfo(const TargetInstrInfo &); // DO NOT IMPLEMENT
void operator=(const TargetInstrInfo &); // DO NOT IMPLEMENT
public:
TargetInstrInfo(const TargetInstrDescriptor *desc, unsigned NumOpcodes);
virtual ~TargetInstrInfo();
// Invariant: All instruction sets use opcode #0 as the PHI instruction
enum { PHI = 0 };
unsigned getNumOpcodes() const { return NumOpcodes; }
/// get - Return the machine instruction descriptor that corresponds to the
/// specified instruction opcode.
///
const TargetInstrDescriptor& get(MachineOpCode opCode) const {
assert((unsigned)opCode < NumOpcodes);
return desc[opCode];
}
const char *getName(MachineOpCode opCode) const {
return get(opCode).Name;
}
int getNumOperands(MachineOpCode opCode) const {
return get(opCode).numOperands;
}
InstrSchedClass getSchedClass(MachineOpCode opCode) const {
return get(opCode).schedClass;
}
const unsigned *getImplicitUses(MachineOpCode opCode) const {
return get(opCode).ImplicitUses;
}
const unsigned *getImplicitDefs(MachineOpCode opCode) const {
return get(opCode).ImplicitDefs;
}
//
// Query instruction class flags according to the machine-independent
// flags listed above.
//
bool isReturn(MachineOpCode opCode) const {
return get(opCode).Flags & M_RET_FLAG;
}
bool isPseudoInstr(MachineOpCode opCode) const {
return get(opCode).Flags & M_PSEUDO_FLAG;
}
bool isTwoAddrInstr(MachineOpCode opCode) const {
return get(opCode).Flags & M_2_ADDR_FLAG;
}
bool isTerminatorInstr(unsigned Opcode) const {
return get(Opcode).Flags & M_TERMINATOR_FLAG;
}
//
// Return true if the instruction is a register to register move and
// leave the source and dest operands in the passed parameters.
//
virtual bool isMoveInstr(const MachineInstr& MI,
unsigned& sourceReg,
unsigned& destReg) const {
return false;
}
//-------------------------------------------------------------------------
// Code generation support for creating individual machine instructions
//
// WARNING: These methods are Sparc specific
//
// DO NOT USE ANY OF THESE METHODS THEY ARE DEPRECATED!
//
//-------------------------------------------------------------------------
int getResultPos(MachineOpCode opCode) const {
return get(opCode).resultPos;
}
unsigned getNumDelaySlots(MachineOpCode opCode) const {
return get(opCode).numDelaySlots;
}
bool isCCInstr(MachineOpCode opCode) const {
return get(opCode).Flags & M_CC_FLAG;
}
bool isNop(MachineOpCode opCode) const {
return get(opCode).Flags & M_NOP_FLAG;
}
bool isBranch(MachineOpCode opCode) const {
return get(opCode).Flags & M_BRANCH_FLAG;
}
bool isCall(MachineOpCode opCode) const {
return get(opCode).Flags & M_CALL_FLAG;
}
bool isLoad(MachineOpCode opCode) const {
return get(opCode).Flags & M_LOAD_FLAG;
}
bool isStore(MachineOpCode opCode) const {
return get(opCode).Flags & M_STORE_FLAG;
}
bool isDummyPhiInstr(MachineOpCode opCode) const {
return get(opCode).Flags & M_DUMMY_PHI_FLAG;
}
// Check if an instruction can be issued before its operands are ready,
// or if a subsequent instruction that uses its result can be issued
// before the results are ready.
// Default to true since most instructions on many architectures allow this.
//
virtual bool hasOperandInterlock(MachineOpCode opCode) const {
return true;
}
virtual bool hasResultInterlock(MachineOpCode opCode) const {
return true;
}
//
// Latencies for individual instructions and instruction pairs
//
virtual int minLatency(MachineOpCode opCode) const {
return get(opCode).latency;
}
virtual int maxLatency(MachineOpCode opCode) const {
return get(opCode).latency;
}
//
// Which operand holds an immediate constant? Returns -1 if none
//
virtual int getImmedConstantPos(MachineOpCode opCode) const {
return -1; // immediate position is machine specific, so say -1 == "none"
}
// Check if the specified constant fits in the immediate field
// of this machine instruction
//
virtual bool constantFitsInImmedField(MachineOpCode opCode,
int64_t intValue) const;
// Return the largest positive constant that can be held in the IMMED field
// of this machine instruction.
// isSignExtended is set to true if the value is sign-extended before use
// (this is true for all immediate fields in SPARC instructions).
// Return 0 if the instruction has no IMMED field.
//
virtual uint64_t maxImmedConstant(MachineOpCode opCode,
bool &isSignExtended) const {
isSignExtended = get(opCode).immedIsSignExtended;
return get(opCode).maxImmedConst;
}
};
} // End llvm namespace
#endif