//===----------------------------------------------------------------------===//
//
// This file defines the FastISel class.
-//
+//
//===----------------------------------------------------------------------===//
-
+
#ifndef LLVM_CODEGEN_FASTISEL_H
#define LLVM_CODEGEN_FASTISEL_H
#include "llvm/ADT/DenseMap.h"
-#ifndef NDEBUG
-#include "llvm/ADT/SmallSet.h"
-#endif
#include "llvm/CodeGen/ValueTypes.h"
+#include "llvm/CodeGen/MachineBasicBlock.h"
namespace llvm {
class AllocaInst;
+class Constant;
class ConstantFP;
class FunctionLoweringInfo;
class Instruction;
+class LoadInst;
class MachineBasicBlock;
class MachineConstantPool;
class MachineFunction;
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:
- MachineBasicBlock *MBB;
DenseMap<const Value *, unsigned> LocalValueMap;
FunctionLoweringInfo &FuncInfo;
MachineRegisterInfo &MRI;
const TargetInstrInfo &TII;
const TargetLowering &TLI;
const TargetRegisterInfo &TRI;
- bool IsBottomUp;
+
+ /// 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:
- /// startNewBlock - Set the current block to which generated machine
- /// instructions will be appended, and clear the local CSE map.
- ///
- void startNewBlock(MachineBasicBlock *mbb) {
- setCurrentBlock(mbb);
- LocalValueMap.clear();
+ /// 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;
}
- /// setCurrentBlock - Set the current block to which generated machine
- /// instructions will be appended.
+ /// startNewBlock - Set the current block to which generated machine
+ /// instructions will be appended, and clear the local CSE map.
///
- void setCurrentBlock(MachineBasicBlock *mbb) {
- MBB = mbb;
- }
+ void startNewBlock();
/// getCurDebugLoc() - Return current debug location information.
DebugLoc getCurDebugLoc() const { return DL; }
/// 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();
+
+ 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:
unsigned Opcode,
unsigned Op0, bool Op0IsKill,
uint64_t Imm, MVT 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 VT,
- unsigned Opcode,
- unsigned Op0, bool Op0IsKill,
- const ConstantFP *FPImm, 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.
unsigned Op0, bool Op0IsKill,
unsigned Op1, bool Op1IsKill);
- /// FastEmitInst_ri - Emit a MachineInstr with two register operands
+ /// 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 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,
/// the CFG.
void FastEmitBranch(MachineBasicBlock *MBB, DebugLoc DL);
- unsigned UpdateValueMap(const Value* I, unsigned Reg);
+ void UpdateValueMap(const Value* I, unsigned Reg, unsigned NumRegs = 1);
unsigned createResultReg(const TargetRegisterClass *RC);
-
- /// TargetMaterializeConstant - Emit a constant in a register using
+
+ /// TargetMaterializeConstant - Emit a constant in a register using
/// target-specific logic, such as constant pool loads.
virtual unsigned TargetMaterializeConstant(const Constant* C) {
return 0;
return 0;
}
-private:
- bool SelectLoad(const User *I);
+ virtual unsigned TargetMaterializeFloatZero(const ConstantFP* CF) {
+ return 0;
+ }
+private:
bool SelectBinaryOp(const User *I, unsigned ISDOpcode);
bool SelectFNeg(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
/// 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;
+
+ /// removeDeadCode - Remove all dead instructions between the I and E.
+ void removeDeadCode(MachineBasicBlock::iterator I,
+ MachineBasicBlock::iterator E);
};
}