llvm-6502/include/llvm/Target/TargetInstrInfo.h
Chris Lattner 9ca5a2a33e The NOOP instruction is no longer needed. Instead, use the
TargetInstrInfo::isNOPinstr method


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@7530 91177308-0d34-0410-b5e6-96231b3b80d8
2003-08-03 18:52:15 +00:00

412 lines
16 KiB
C++

//===-- llvm/Target/TargetInstrInfo.h - Instruction Info --------*- C++ -*-===//
//
// 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>
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 int MachineOpCode;
typedef unsigned InstrSchedClass;
const MachineOpCode INVALID_MACHINE_OPCODE = -1;
//---------------------------------------------------------------------------
// 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_ARITH_FLAG = 1 << 4;
const unsigned M_CC_FLAG = 1 << 6;
const unsigned M_LOGICAL_FLAG = 1 << 6;
const unsigned M_INT_FLAG = 1 << 7;
const unsigned M_FLOAT_FLAG = 1 << 8;
const unsigned M_CONDL_FLAG = 1 << 9;
const unsigned M_LOAD_FLAG = 1 << 10;
const unsigned M_PREFETCH_FLAG = 1 << 11;
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 IMMMED 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 descSize; // 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 descSize,
unsigned numRealOpCodes);
virtual ~TargetInstrInfo();
// Invariant: All instruction sets use opcode #0 as the PHI instruction
enum { PHI = 0 };
unsigned getNumRealOpCodes() const { return numRealOpCodes; }
unsigned getNumTotalOpCodes() const { return descSize; }
/// get - Return the machine instruction descriptor that corresponds to the
/// specified instruction opcode.
///
const TargetInstrDescriptor& get(MachineOpCode opCode) const {
assert(opCode >= 0 && opCode < (int)descSize);
return desc[opCode];
}
const char *getName(MachineOpCode opCode) const {
return get(opCode).Name;
}
int getNumOperands(MachineOpCode opCode) const {
return get(opCode).numOperands;
}
int getResultPos(MachineOpCode opCode) const {
return get(opCode).resultPos;
}
unsigned getNumDelaySlots(MachineOpCode opCode) const {
return get(opCode).numDelaySlots;
}
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 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 isReturn(MachineOpCode opCode) const {
return get(opCode).Flags & M_RET_FLAG;
}
bool isControlFlow(MachineOpCode opCode) const {
return get(opCode).Flags & M_BRANCH_FLAG
|| get(opCode).Flags & M_CALL_FLAG
|| get(opCode).Flags & M_RET_FLAG;
}
bool isArith(MachineOpCode opCode) const {
return get(opCode).Flags & M_ARITH_FLAG;
}
bool isCCInstr(MachineOpCode opCode) const {
return get(opCode).Flags & M_CC_FLAG;
}
bool isLogical(MachineOpCode opCode) const {
return get(opCode).Flags & M_LOGICAL_FLAG;
}
bool isIntInstr(MachineOpCode opCode) const {
return get(opCode).Flags & M_INT_FLAG;
}
bool isFloatInstr(MachineOpCode opCode) const {
return get(opCode).Flags & M_FLOAT_FLAG;
}
bool isConditional(MachineOpCode opCode) const {
return get(opCode).Flags & M_CONDL_FLAG;
}
bool isLoad(MachineOpCode opCode) const {
return get(opCode).Flags & M_LOAD_FLAG;
}
bool isPrefetch(MachineOpCode opCode) const {
return get(opCode).Flags & M_PREFETCH_FLAG;
}
bool isLoadOrPrefetch(MachineOpCode opCode) const {
return get(opCode).Flags & M_LOAD_FLAG
|| get(opCode).Flags & M_PREFETCH_FLAG;
}
bool isStore(MachineOpCode opCode) const {
return get(opCode).Flags & M_STORE_FLAG;
}
bool isMemoryAccess(MachineOpCode opCode) const {
return get(opCode).Flags & M_LOAD_FLAG
|| get(opCode).Flags & M_PREFETCH_FLAG
|| get(opCode).Flags & M_STORE_FLAG;
}
bool isDummyPhiInstr(MachineOpCode opCode) const {
return get(opCode).Flags & M_DUMMY_PHI_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;
}
// 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 +ve constant that can be held in the IMMMED 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;
}
//-------------------------------------------------------------------------
// Queries about representation of LLVM quantities (e.g., constants)
//-------------------------------------------------------------------------
/// ConstantTypeMustBeLoaded - Test if this type of constant must be loaded
/// from memory into a register, i.e., cannot be set bitwise in register and
/// cannot use immediate fields of instructions. Note that this only makes
/// sense for primitive types.
///
virtual bool ConstantTypeMustBeLoaded(const Constant* CV) const;
// Test if this constant may not fit in the immediate field of the
// machine instructions (probably) generated for this instruction.
//
virtual bool ConstantMayNotFitInImmedField(const Constant* CV,
const Instruction* I) const {
return true; // safe but very conservative
}
/// createNOPinstr - returns the target's implementation of NOP, which is
/// usually a pseudo-instruction, implemented by a degenerate version of
/// another instruction, e.g. X86: xchg ax, ax; SparcV9: sethi g0, 0
///
virtual MachineInstr* createNOPinstr() const = 0;
/// isNOPinstr - not having a special NOP opcode, we need to know if a given
/// instruction is interpreted as an `official' NOP instr, i.e., there may be
/// more than one way to `do nothing' but only one canonical way to slack off.
///
virtual bool isNOPinstr(const MachineInstr &MI) const = 0;
//-------------------------------------------------------------------------
// Code generation support for creating individual machine instructions
//
// WARNING: These methods are Sparc specific
//
//-------------------------------------------------------------------------
// Get certain common op codes for the current target. this and all the
// Create* methods below should be moved to a machine code generation class
//
virtual MachineOpCode getNOPOpCode() const { abort(); }
// Get the value of an integral constant in the form that must
// be put into the machine register. The specified constant is interpreted
// as (i.e., converted if necessary to) the specified destination type. The
// result is always returned as an uint64_t, since the representation of
// int64_t and uint64_t are identical. The argument can be any known const.
//
// isValidConstant is set to true if a valid constant was found.
//
virtual uint64_t ConvertConstantToIntType(const TargetMachine &target,
const Value *V,
const Type *destType,
bool &isValidConstant) const {
abort();
}
// Create an instruction sequence to put the constant `val' into
// the virtual register `dest'. `val' may be a Constant or a
// GlobalValue, viz., the constant address of a global variable or function.
// The generated instructions are returned in `mvec'.
// Any temp. registers (TmpInstruction) created are recorded in mcfi.
// Symbolic constants or constants that must be accessed from memory
// are added to the constant pool via MachineFunction::get(F).
//
virtual void CreateCodeToLoadConst(const TargetMachine& target,
Function* F,
Value* val,
Instruction* dest,
std::vector<MachineInstr*>& mvec,
MachineCodeForInstruction& mcfi) const {
abort();
}
// Create an instruction sequence to copy an integer value `val'
// to a floating point value `dest' by copying to memory and back.
// val must be an integral type. dest must be a Float or Double.
// The generated instructions are returned in `mvec'.
// Any temp. registers (TmpInstruction) created are recorded in mcfi.
// Any stack space required is allocated via mcff.
//
virtual void CreateCodeToCopyIntToFloat(const TargetMachine& target,
Function* F,
Value* val,
Instruction* dest,
std::vector<MachineInstr*>& mvec,
MachineCodeForInstruction& MI) const {
abort();
}
// Similarly, create an instruction sequence to copy an FP value
// `val' to an integer value `dest' by copying to memory and back.
// The generated instructions are returned in `mvec'.
// Any temp. registers (TmpInstruction) created are recorded in mcfi.
// Any stack space required is allocated via mcff.
//
virtual void CreateCodeToCopyFloatToInt(const TargetMachine& target,
Function* F,
Value* val,
Instruction* dest,
std::vector<MachineInstr*>& mvec,
MachineCodeForInstruction& MI) const {
abort();
}
// Create instruction(s) to copy src to dest, for arbitrary types
// The generated instructions are returned in `mvec'.
// Any temp. registers (TmpInstruction) created are recorded in mcfi.
// Any stack space required is allocated via mcff.
//
virtual void CreateCopyInstructionsByType(const TargetMachine& target,
Function* F,
Value* src,
Instruction* dest,
std::vector<MachineInstr*>& mvec,
MachineCodeForInstruction& MI) const {
abort();
}
// Create instruction sequence to produce a sign-extended register value
// from an arbitrary sized value (sized in bits, not bytes).
// The generated instructions are appended to `mvec'.
// Any temp. registers (TmpInstruction) created are recorded in mcfi.
// Any stack space required is allocated via mcff.
//
virtual void CreateSignExtensionInstructions(const TargetMachine& target,
Function* F,
Value* srcVal,
Value* destVal,
unsigned numLowBits,
std::vector<MachineInstr*>& mvec,
MachineCodeForInstruction& MI) const {
abort();
}
// Create instruction sequence to produce a zero-extended register value
// from an arbitrary sized value (sized in bits, not bytes).
// The generated instructions are appended to `mvec'.
// Any temp. registers (TmpInstruction) created are recorded in mcfi.
// Any stack space required is allocated via mcff.
//
virtual void CreateZeroExtensionInstructions(const TargetMachine& target,
Function* F,
Value* srcVal,
Value* destVal,
unsigned srcSizeInBits,
std::vector<MachineInstr*>& mvec,
MachineCodeForInstruction& mcfi) const {
abort();
}
};
#endif