-//===-- FastISel.h - Definition of the FastISel class ---------------------===//
+//===-- FastISel.h - Definition of the FastISel class ---*- C++ -*---------===//
//
// The LLVM Compiler Infrastructure
//
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
-//
-// This file defines the FastISel class.
-//
+///
+/// \file
+/// This file defines the FastISel class.
+///
//===----------------------------------------------------------------------===//
-
+
#ifndef LLVM_CODEGEN_FASTISEL_H
#define LLVM_CODEGEN_FASTISEL_H
-#include "llvm/BasicBlock.h"
#include "llvm/ADT/DenseMap.h"
-#include "llvm/CodeGen/SelectionDAGNodes.h"
+#include "llvm/CodeGen/MachineBasicBlock.h"
+#include "llvm/CodeGen/ValueTypes.h"
namespace llvm {
+class AllocaInst;
+class Constant;
class ConstantFP;
-class MachineBasicBlock;
+class FunctionLoweringInfo;
+class Instruction;
+class LoadInst;
+class MachineConstantPool;
class MachineFunction;
+class MachineInstr;
+class MachineFrameInfo;
class MachineRegisterInfo;
-class TargetData;
+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.
+/// 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:
- MachineBasicBlock *MBB;
DenseMap<const Value *, unsigned> LocalValueMap;
- DenseMap<const Value *, unsigned> &ValueMap;
- DenseMap<const BasicBlock *, MachineBasicBlock *> &MBBMap;
- MachineFunction &MF;
+ FunctionLoweringInfo &FuncInfo;
MachineRegisterInfo &MRI;
+ MachineFrameInfo &MFI;
+ MachineConstantPool &MCP;
+ DebugLoc DL;
const TargetMachine &TM;
- const TargetData &TD;
+ 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:
- /// setCurrentBlock - Set the current block, to which generated
- /// machine instructions will be appended.
- ///
- void setCurrentBlock(MachineBasicBlock *mbb) {
- MBB = mbb;
+ /// Return the position of the last instruction emitted for materializing
+ /// constants for use in the current block.
+ MachineInstr *getLastLocalValue() { return LastLocalValue; }
+
+ /// 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;
}
- /// 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.
+ /// Set the current block to which generated machine instructions will be
+ /// appended, and clear the local CSE map.
+ void startNewBlock();
+
+ /// Return current debug location information.
+ DebugLoc getCurDebugLoc() const { return DL; }
+
+ /// Do "fast" instruction selection for function arguments and append machine
+ /// instructions to the current block. Return true if it is successful.
+ bool LowerArguments();
+
+ /// 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);
+
+ /// 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);
+
+ /// Create a virtual register and arrange for it to be assigned the value for
+ /// the given LLVM value.
+ unsigned getRegForValue(const Value *V);
+
+ /// 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);
+
+ /// 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);
+
+ /// \brief We're checking to see if we can fold \p LI into \p FoldInst. Note
+ /// that we could have a sequence where multiple LLVM IR instructions are
+ /// folded into the same machineinstr. For example we could have:
///
- bool SelectInstruction(Instruction *I);
+ /// A: x = load i32 *P
+ /// B: y = icmp A, 42
+ /// C: br y, ...
+ ///
+ /// In this scenario, \p LI is "A", and \p FoldInst is "C". We know about "B"
+ /// (and any other folded instructions) because it is between A and C.
+ ///
+ /// If we succeed folding, return true.
+ bool tryToFoldLoad(const LoadInst *LI, const Instruction *FoldInst);
- /// 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.
+ /// \brief 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
- TargetSelectInstruction(Instruction *I) = 0;
+ /// This method should be implemented by targets.
+ virtual bool tryToFoldLoadIntoMI(MachineInstr * /*MI*/, unsigned /*OpNo*/,
+ const LoadInst * /*LI*/) {
+ return false;
+ }
+
+ /// Reset InsertPt to prepare for inserting instructions into the current
+ /// block.
+ void recomputeInsertPt();
+
+ /// Remove all dead instructions between the I and E.
+ void removeDeadCode(MachineBasicBlock::iterator I,
+ MachineBasicBlock::iterator E);
+
+ struct SavePoint {
+ MachineBasicBlock::iterator InsertPt;
+ DebugLoc DL;
+ };
- /// getRegForValue - Create a virtual register and arrange for it to
- /// be assigned the value for the given LLVM value.
- unsigned getRegForValue(Value *V);
+ /// Prepare InsertPt to begin inserting instructions into the local value area
+ /// and return the old insert position.
+ SavePoint enterLocalValueArea();
+
+ /// Reset InsertPt to the given old insert position.
+ void leaveLocalValueArea(SavePoint Old);
virtual ~FastISel();
protected:
- FastISel(MachineFunction &mf,
- DenseMap<const Value *, unsigned> &vm,
- DenseMap<const BasicBlock *, MachineBasicBlock *> &bm);
-
- /// 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::SimpleValueType VT,
- MVT::SimpleValueType RetVT,
- ISD::NodeType 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::SimpleValueType VT,
- MVT::SimpleValueType RetVT,
- ISD::NodeType Opcode, unsigned Op0);
+ explicit FastISel(FunctionLoweringInfo &funcInfo,
+ const TargetLibraryInfo *libInfo);
- /// 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::SimpleValueType VT,
- MVT::SimpleValueType RetVT,
- ISD::NodeType Opcode,
- unsigned Op0, unsigned Op1);
-
- /// 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::SimpleValueType VT,
- MVT::SimpleValueType RetVT,
- ISD::NodeType Opcode,
- unsigned Op0, 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::SimpleValueType VT,
- MVT::SimpleValueType RetVT,
- ISD::NodeType Opcode,
- unsigned Op0, 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::SimpleValueType VT,
- MVT::SimpleValueType RetVT,
- ISD::NodeType Opcode,
- unsigned Op0, unsigned Op1, 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::SimpleValueType VT,
- ISD::NodeType Opcode,
- unsigned Op0, uint64_t Imm,
- MVT::SimpleValueType ImmType);
-
- /// FastEmit_rf_ - This method is a wrapper of FastEmit_rf. It first tries
- /// to emit an instruction with an immediate operand using FastEmit_rf.
- /// If that fails, it materializes the immediate into a register and try
- /// FastEmit_rr instead.
- unsigned FastEmit_rf_(MVT::SimpleValueType VT,
- ISD::NodeType Opcode,
- unsigned Op0, ConstantFP *FPImm,
- MVT::SimpleValueType ImmType);
+ /// 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;
- /// 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::SimpleValueType VT,
- MVT::SimpleValueType RetVT,
- ISD::NodeType Opcode,
+ /// This method is called by target-independent code to do target specific
+ /// argument lowering. It returns true if it was successful.
+ virtual bool FastLowerArguments();
+
+ /// 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);
+
+ /// 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);
+
+ /// 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);
+
+ /// 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);
+
+ /// 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);
+
+ /// 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);
+
+ /// \brief 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);
+
+ /// 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::SimpleValueType VT,
- MVT::SimpleValueType RetVT,
- ISD::NodeType Opcode,
- ConstantFP *FPImm);
+ /// 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.
- ///
+ /// 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.
- ///
+ /// 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);
+ unsigned Op0, bool Op0IsKill);
- /// FastEmitInst_rr - Emit a MachineInstr with two register operands
- /// and a result register in the given register class.
- ///
+ /// 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, unsigned Op1);
+ unsigned Op0, bool Op0IsKill,
+ unsigned Op1, bool Op1IsKill);
- /// FastEmitInst_ri - Emit a MachineInstr with two register operands
- /// and a result register in the given register class.
- ///
+ /// 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);
+
+ /// 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, uint64_t Imm);
+ unsigned Op0, bool Op0IsKill,
+ uint64_t Imm);
- /// FastEmitInst_rf - Emit a MachineInstr with two register operands
- /// and a result register in the given register class.
- ///
+ /// 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);
+
+ /// 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, ConstantFP *FPImm);
+ 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.
- ///
+ /// 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, unsigned Op1, uint64_t Imm);
-
- /// FastEmitInst_i - Emit a MachineInstr with a single immediate
- /// operand, and a result register in the given register class.
+ unsigned Op0, bool Op0IsKill,
+ unsigned Op1, bool Op1IsKill,
+ uint64_t Imm);
+
+ /// 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);
+
+ /// 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_extractsubreg - Emit a MachineInstr for an extract_subreg
- /// from a specified index of a superregister.
- unsigned FastEmitInst_extractsubreg(unsigned Op0, uint32_t Idx);
+ /// Emit a MachineInstr with a two immediate operands.
+ unsigned FastEmitInst_ii(unsigned MachineInstrOpcode,
+ const TargetRegisterClass *RC,
+ uint64_t Imm1, uint64_t Imm2);
+
+ /// 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);
+
+ /// 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);
+
+ /// 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(Instruction* I, unsigned Reg);
+ void UpdateValueMap(const Value* I, unsigned Reg, unsigned NumRegs = 1);
unsigned createResultReg(const TargetRegisterClass *RC);
+ /// Emit a constant in a register using target-specific logic, such as
+ /// constant pool loads.
+ virtual unsigned TargetMaterializeConstant(const Constant* C) {
+ return 0;
+ }
+
+ /// 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(Instruction *I, ISD::NodeType ISDOpcode);
+ bool SelectBinaryOp(const User *I, unsigned ISDOpcode);
- bool SelectGetElementPtr(Instruction *I);
+ bool SelectFNeg(const User *I);
- bool SelectBitCast(Instruction *I);
-
- bool SelectCast(Instruction *I, ISD::NodeType Opcode);
+ 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);
+
+ /// \brief 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);
+
+ /// 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);
+
+ /// 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();
+
+ /// Test whether the given value has exactly one use.
+ bool hasTrivialKill(const Value *V) const;
};
}
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