llvm-6502/include/llvm/CodeGen/FastISel.h

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//===-- FastISel.h - Definition of the FastISel class ---------------------===//
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
// This file defines the FastISel class.
//
//===----------------------------------------------------------------------===//
#ifndef LLVM_CODEGEN_FASTISEL_H
#define LLVM_CODEGEN_FASTISEL_H
#include "llvm/ADT/DenseMap.h"
#include "llvm/CodeGen/MachineBasicBlock.h"
#include "llvm/CodeGen/ValueTypes.h"
namespace llvm {
class AllocaInst;
class Constant;
class ConstantFP;
class FunctionLoweringInfo;
class Instruction;
class LoadInst;
class MachineBasicBlock;
class MachineConstantPool;
class MachineFunction;
class MachineInstr;
class MachineFrameInfo;
class MachineRegisterInfo;
class DataLayout;
class TargetInstrInfo;
class TargetLibraryInfo;
class TargetLowering;
class TargetMachine;
class TargetRegisterClass;
class TargetRegisterInfo;
class User;
class Value;
/// FastISel - This is a fast-path instruction selection class that
/// generates poor code and doesn't support illegal types or non-trivial
/// lowering, but runs quickly.
class FastISel {
protected:
DenseMap<const Value *, unsigned> LocalValueMap;
FunctionLoweringInfo &FuncInfo;
MachineRegisterInfo &MRI;
MachineFrameInfo &MFI;
MachineConstantPool &MCP;
DebugLoc DL;
const TargetMachine &TM;
const DataLayout &TD;
const TargetInstrInfo &TII;
const TargetLowering &TLI;
const TargetRegisterInfo &TRI;
const TargetLibraryInfo *LibInfo;
/// The position of the last instruction for materializing constants
/// for use in the current block. It resets to EmitStartPt when it
/// makes sense (for example, it's usually profitable to avoid function
/// calls between the definition and the use)
MachineInstr *LastLocalValue;
/// The top most instruction in the current block that is allowed for
/// emitting local variables. LastLocalValue resets to EmitStartPt when
/// it makes sense (for example, on function calls)
MachineInstr *EmitStartPt;
public:
/// getLastLocalValue - Return the position of the last instruction
/// emitted for materializing constants for use in the current block.
MachineInstr *getLastLocalValue() { return LastLocalValue; }
/// setLastLocalValue - Update the position of the last instruction
/// emitted for materializing constants for use in the current block.
void setLastLocalValue(MachineInstr *I) {
EmitStartPt = I;
LastLocalValue = I;
}
/// startNewBlock - Set the current block to which generated machine
/// instructions will be appended, and clear the local CSE map.
///
void startNewBlock();
/// getCurDebugLoc() - Return current debug location information.
DebugLoc getCurDebugLoc() const { return DL; }
/// LowerArguments - Do "fast" instruction selection for function arguments
/// and append machine instructions to the current block. Return true if
/// it is successful.
bool LowerArguments();
/// SelectInstruction - Do "fast" instruction selection for the given
/// LLVM IR instruction, and append generated machine instructions to
/// the current block. Return true if selection was successful.
///
bool SelectInstruction(const Instruction *I);
/// SelectOperator - Do "fast" instruction selection for the given
/// LLVM IR operator (Instruction or ConstantExpr), and append
/// generated machine instructions to the current block. Return true
/// if selection was successful.
///
bool SelectOperator(const User *I, unsigned Opcode);
/// getRegForValue - Create a virtual register and arrange for it to
/// be assigned the value for the given LLVM value.
unsigned getRegForValue(const Value *V);
/// lookUpRegForValue - Look up the value to see if its value is already
/// cached in a register. It may be defined by instructions across blocks or
/// defined locally.
unsigned lookUpRegForValue(const Value *V);
/// getRegForGEPIndex - This is a wrapper around getRegForValue that also
/// takes care of truncating or sign-extending the given getelementptr
/// index value.
std::pair<unsigned, bool> getRegForGEPIndex(const Value *V);
/// TryToFoldLoad - The specified machine instr operand is a vreg, and that
/// vreg is being provided by the specified load instruction. If possible,
/// try to fold the load as an operand to the instruction, returning true if
/// possible.
virtual bool TryToFoldLoad(MachineInstr * /*MI*/, unsigned /*OpNo*/,
const LoadInst * /*LI*/) {
return false;
}
/// recomputeInsertPt - Reset InsertPt to prepare for inserting instructions
/// into the current block.
void recomputeInsertPt();
/// removeDeadCode - Remove all dead instructions between the I and E.
void removeDeadCode(MachineBasicBlock::iterator I,
MachineBasicBlock::iterator E);
struct SavePoint {
MachineBasicBlock::iterator InsertPt;
DebugLoc DL;
};
/// enterLocalValueArea - Prepare InsertPt to begin inserting instructions
/// into the local value area and return the old insert position.
SavePoint enterLocalValueArea();
/// leaveLocalValueArea - Reset InsertPt to the given old insert position.
void leaveLocalValueArea(SavePoint Old);
virtual ~FastISel();
protected:
explicit FastISel(FunctionLoweringInfo &funcInfo,
const TargetLibraryInfo *libInfo);
/// TargetSelectInstruction - This method is called by target-independent
/// code when the normal FastISel process fails to select an instruction.
/// This gives targets a chance to emit code for anything that doesn't
/// fit into FastISel's framework. It returns true if it was successful.
///
virtual bool
TargetSelectInstruction(const Instruction *I) = 0;
/// FastLowerArguments - This method is called by target-independent code to
/// do target specific argument lowering. It returns true if it was
/// successful.
virtual bool FastLowerArguments();
/// FastEmit_r - This method is called by target-independent code
/// to request that an instruction with the given type and opcode
/// be emitted.
virtual unsigned FastEmit_(MVT VT,
MVT RetVT,
unsigned Opcode);
/// FastEmit_r - This method is called by target-independent code
/// to request that an instruction with the given type, opcode, and
/// register operand be emitted.
///
virtual unsigned FastEmit_r(MVT VT,
MVT RetVT,
unsigned Opcode,
unsigned Op0, bool Op0IsKill);
/// FastEmit_rr - This method is called by target-independent code
/// to request that an instruction with the given type, opcode, and
/// register operands be emitted.
///
virtual unsigned FastEmit_rr(MVT VT,
MVT RetVT,
unsigned Opcode,
unsigned Op0, bool Op0IsKill,
unsigned Op1, bool Op1IsKill);
/// FastEmit_ri - This method is called by target-independent code
/// to request that an instruction with the given type, opcode, and
/// register and immediate operands be emitted.
///
virtual unsigned FastEmit_ri(MVT VT,
MVT RetVT,
unsigned Opcode,
unsigned Op0, bool Op0IsKill,
uint64_t Imm);
/// FastEmit_rf - This method is called by target-independent code
/// to request that an instruction with the given type, opcode, and
/// register and floating-point immediate operands be emitted.
///
virtual unsigned FastEmit_rf(MVT VT,
MVT RetVT,
unsigned Opcode,
unsigned Op0, bool Op0IsKill,
const ConstantFP *FPImm);
/// FastEmit_rri - This method is called by target-independent code
/// to request that an instruction with the given type, opcode, and
/// register and immediate operands be emitted.
///
virtual unsigned FastEmit_rri(MVT VT,
MVT RetVT,
unsigned Opcode,
unsigned Op0, bool Op0IsKill,
unsigned Op1, bool Op1IsKill,
uint64_t Imm);
/// FastEmit_ri_ - This method is a wrapper of FastEmit_ri. It first tries
/// to emit an instruction with an immediate operand using FastEmit_ri.
/// If that fails, it materializes the immediate into a register and try
/// FastEmit_rr instead.
unsigned FastEmit_ri_(MVT VT,
unsigned Opcode,
unsigned Op0, bool Op0IsKill,
uint64_t Imm, MVT ImmType);
/// FastEmit_i - This method is called by target-independent code
/// to request that an instruction with the given type, opcode, and
/// immediate operand be emitted.
virtual unsigned FastEmit_i(MVT VT,
MVT RetVT,
unsigned Opcode,
uint64_t Imm);
/// FastEmit_f - This method is called by target-independent code
/// to request that an instruction with the given type, opcode, and
/// floating-point immediate operand be emitted.
virtual unsigned FastEmit_f(MVT VT,
MVT RetVT,
unsigned Opcode,
const ConstantFP *FPImm);
/// FastEmitInst_ - Emit a MachineInstr with no operands and a
/// result register in the given register class.
///
unsigned FastEmitInst_(unsigned MachineInstOpcode,
const TargetRegisterClass *RC);
/// FastEmitInst_r - Emit a MachineInstr with one register operand
/// and a result register in the given register class.
///
unsigned FastEmitInst_r(unsigned MachineInstOpcode,
const TargetRegisterClass *RC,
unsigned Op0, bool Op0IsKill);
/// FastEmitInst_rr - Emit a MachineInstr with two register operands
/// and a result register in the given register class.
///
unsigned FastEmitInst_rr(unsigned MachineInstOpcode,
const TargetRegisterClass *RC,
unsigned Op0, bool Op0IsKill,
unsigned Op1, bool Op1IsKill);
/// FastEmitInst_rrr - Emit a MachineInstr with three register operands
/// and a result register in the given register class.
///
unsigned FastEmitInst_rrr(unsigned MachineInstOpcode,
const TargetRegisterClass *RC,
unsigned Op0, bool Op0IsKill,
unsigned Op1, bool Op1IsKill,
unsigned Op2, bool Op2IsKill);
/// FastEmitInst_ri - Emit a MachineInstr with a register operand,
/// an immediate, and a result register in the given register class.
///
unsigned FastEmitInst_ri(unsigned MachineInstOpcode,
const TargetRegisterClass *RC,
unsigned Op0, bool Op0IsKill,
uint64_t Imm);
/// FastEmitInst_rii - Emit a MachineInstr with one register operand
/// and two immediate operands.
///
unsigned FastEmitInst_rii(unsigned MachineInstOpcode,
const TargetRegisterClass *RC,
unsigned Op0, bool Op0IsKill,
uint64_t Imm1, uint64_t Imm2);
/// FastEmitInst_rf - Emit a MachineInstr with two register operands
/// and a result register in the given register class.
///
unsigned FastEmitInst_rf(unsigned MachineInstOpcode,
const TargetRegisterClass *RC,
unsigned Op0, bool Op0IsKill,
const ConstantFP *FPImm);
/// FastEmitInst_rri - Emit a MachineInstr with two register operands,
/// an immediate, and a result register in the given register class.
///
unsigned FastEmitInst_rri(unsigned MachineInstOpcode,
const TargetRegisterClass *RC,
unsigned Op0, bool Op0IsKill,
unsigned Op1, bool Op1IsKill,
uint64_t Imm);
/// FastEmitInst_rrii - Emit a MachineInstr with two register operands,
/// two immediates operands, and a result register in the given register
/// class.
unsigned FastEmitInst_rrii(unsigned MachineInstOpcode,
const TargetRegisterClass *RC,
unsigned Op0, bool Op0IsKill,
unsigned Op1, bool Op1IsKill,
uint64_t Imm1, uint64_t Imm2);
/// FastEmitInst_i - Emit a MachineInstr with a single immediate
/// operand, and a result register in the given register class.
unsigned FastEmitInst_i(unsigned MachineInstrOpcode,
const TargetRegisterClass *RC,
uint64_t Imm);
/// FastEmitInst_ii - Emit a MachineInstr with a two immediate operands.
unsigned FastEmitInst_ii(unsigned MachineInstrOpcode,
const TargetRegisterClass *RC,
uint64_t Imm1, uint64_t Imm2);
/// FastEmitInst_extractsubreg - Emit a MachineInstr for an extract_subreg
/// from a specified index of a superregister to a specified type.
unsigned FastEmitInst_extractsubreg(MVT RetVT,
unsigned Op0, bool Op0IsKill,
uint32_t Idx);
/// FastEmitZExtFromI1 - Emit MachineInstrs to compute the value of Op
/// with all but the least significant bit set to zero.
unsigned FastEmitZExtFromI1(MVT VT,
unsigned Op0, bool Op0IsKill);
/// FastEmitBranch - Emit an unconditional branch to the given block,
/// unless it is the immediate (fall-through) successor, and update
/// the CFG.
void FastEmitBranch(MachineBasicBlock *MBB, DebugLoc DL);
void UpdateValueMap(const Value* I, unsigned Reg, unsigned NumRegs = 1);
unsigned createResultReg(const TargetRegisterClass *RC);
/// TargetMaterializeConstant - Emit a constant in a register using
/// target-specific logic, such as constant pool loads.
virtual unsigned TargetMaterializeConstant(const Constant* C) {
return 0;
}
/// TargetMaterializeAlloca - Emit an alloca address in a register using
/// target-specific logic.
virtual unsigned TargetMaterializeAlloca(const AllocaInst* C) {
return 0;
}
virtual unsigned TargetMaterializeFloatZero(const ConstantFP* CF) {
return 0;
}
private:
bool SelectBinaryOp(const User *I, unsigned ISDOpcode);
bool SelectFNeg(const User *I);
bool SelectGetElementPtr(const User *I);
bool SelectCall(const User *I);
bool SelectBitCast(const User *I);
bool SelectCast(const User *I, unsigned Opcode);
bool SelectExtractValue(const User *I);
bool SelectInsertValue(const User *I);
/// HandlePHINodesInSuccessorBlocks - Handle PHI nodes in successor blocks.
/// Emit code to ensure constants are copied into registers when needed.
/// Remember the virtual registers that need to be added to the Machine PHI
/// nodes as input. We cannot just directly add them, because expansion
/// might result in multiple MBB's for one BB. As such, the start of the
/// BB might correspond to a different MBB than the end.
bool HandlePHINodesInSuccessorBlocks(const BasicBlock *LLVMBB);
/// materializeRegForValue - Helper for getRegForVale. This function is
/// called when the value isn't already available in a register and must
/// be materialized with new instructions.
unsigned materializeRegForValue(const Value *V, MVT VT);
/// flushLocalValueMap - clears LocalValueMap and moves the area for the
/// new local variables to the beginning of the block. It helps to avoid
/// spilling cached variables across heavy instructions like calls.
void flushLocalValueMap();
/// hasTrivialKill - Test whether the given value has exactly one use.
bool hasTrivialKill(const Value *V) const;
};
}
#endif