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1//===- InstrEmitter.h - Emit MachineInstrs for the SelectionDAG -*- C++ -*--==//2//3// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.4// See https://llvm.org/LICENSE.txt for license information.5// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception6//7//===----------------------------------------------------------------------===//8//9// This declares the Emit routines for the SelectionDAG class, which creates10// MachineInstrs based on the decisions of the SelectionDAG instruction11// selection.12//13//===----------------------------------------------------------------------===//14 15#ifndef LLVM_LIB_CODEGEN_SELECTIONDAG_INSTREMITTER_H16#define LLVM_LIB_CODEGEN_SELECTIONDAG_INSTREMITTER_H17 18#include "llvm/ADT/DenseMap.h"19#include "llvm/CodeGen/MachineBasicBlock.h"20#include "llvm/CodeGen/SelectionDAGNodes.h"21 22namespace llvm {23 24class MachineInstrBuilder;25class MCInstrDesc;26class SDDbgLabel;27class SDDbgValue;28class SDDbgOperand;29class TargetLowering;30class TargetMachine;31 32class LLVM_LIBRARY_VISIBILITY InstrEmitter {33public:34 using VRBaseMapType = SmallDenseMap<SDValue, Register, 16>;35 36private:37 MachineFunction *MF;38 MachineRegisterInfo *MRI;39 const TargetInstrInfo *TII;40 const TargetRegisterInfo *TRI;41 const TargetLowering *TLI;42 43 MachineBasicBlock *MBB;44 MachineBasicBlock::iterator InsertPos;45 46 /// Should we try to produce DBG_INSTR_REF instructions?47 bool EmitDebugInstrRefs;48 49 /// EmitCopyFromReg - Generate machine code for an CopyFromReg node or an50 /// implicit physical register output.51 void EmitCopyFromReg(SDValue Op, bool IsClone, Register SrcReg,52 VRBaseMapType &VRBaseMap);53 54 void CreateVirtualRegisters(SDNode *Node,55 MachineInstrBuilder &MIB,56 const MCInstrDesc &II,57 bool IsClone, bool IsCloned,58 VRBaseMapType &VRBaseMap);59 60 /// getVR - Return the virtual register corresponding to the specified result61 /// of the specified node.62 Register getVR(SDValue Op, VRBaseMapType &VRBaseMap);63 64 /// AddRegisterOperand - Add the specified register as an operand to the65 /// specified machine instr. Insert register copies if the register is66 /// not in the required register class.67 void AddRegisterOperand(MachineInstrBuilder &MIB,68 SDValue Op,69 unsigned IIOpNum,70 const MCInstrDesc *II,71 VRBaseMapType &VRBaseMap,72 bool IsDebug, bool IsClone, bool IsCloned);73 74 /// AddOperand - Add the specified operand to the specified machine instr. II75 /// specifies the instruction information for the node, and IIOpNum is the76 /// operand number (in the II) that we are adding. IIOpNum and II are used for77 /// assertions only.78 void AddOperand(MachineInstrBuilder &MIB,79 SDValue Op,80 unsigned IIOpNum,81 const MCInstrDesc *II,82 VRBaseMapType &VRBaseMap,83 bool IsDebug, bool IsClone, bool IsCloned);84 85 /// ConstrainForSubReg - Try to constrain VReg to a register class that86 /// supports SubIdx sub-registers. Emit a copy if that isn't possible.87 /// Return the virtual register to use.88 Register ConstrainForSubReg(Register VReg, unsigned SubIdx, MVT VT,89 bool isDivergent, const DebugLoc &DL);90 91 /// EmitSubregNode - Generate machine code for subreg nodes.92 ///93 void EmitSubregNode(SDNode *Node, VRBaseMapType &VRBaseMap, bool IsClone,94 bool IsCloned);95 96 /// EmitCopyToRegClassNode - Generate machine code for COPY_TO_REGCLASS nodes.97 /// COPY_TO_REGCLASS is just a normal copy, except that the destination98 /// register is constrained to be in a particular register class.99 ///100 void EmitCopyToRegClassNode(SDNode *Node, VRBaseMapType &VRBaseMap);101 102 /// EmitRegSequence - Generate machine code for REG_SEQUENCE nodes.103 ///104 void EmitRegSequence(SDNode *Node, VRBaseMapType &VRBaseMap, bool IsClone,105 bool IsCloned);106 107public:108 /// CountResults - The results of target nodes have register or immediate109 /// operands first, then an optional chain, and optional flag operands110 /// (which do not go into the machine instrs.)111 static unsigned CountResults(SDNode *Node);112 113 void AddDbgValueLocationOps(MachineInstrBuilder &MIB,114 const MCInstrDesc &DbgValDesc,115 ArrayRef<SDDbgOperand> Locations,116 VRBaseMapType &VRBaseMap);117 118 /// EmitDbgValue - Generate machine instruction for a dbg_value node.119 ///120 MachineInstr *EmitDbgValue(SDDbgValue *SD, VRBaseMapType &VRBaseMap);121 122 /// Emit a dbg_value as a DBG_INSTR_REF. May produce DBG_VALUE $noreg instead123 /// if there is no variable location; alternately a half-formed DBG_INSTR_REF124 /// that refers to a virtual register and is corrected later in isel.125 MachineInstr *EmitDbgInstrRef(SDDbgValue *SD, VRBaseMapType &VRBaseMap);126 127 /// Emit a DBG_VALUE $noreg, indicating a variable has no location.128 MachineInstr *EmitDbgNoLocation(SDDbgValue *SD);129 130 /// Emit a DBG_VALUE_LIST from the operands to SDDbgValue.131 MachineInstr *EmitDbgValueList(SDDbgValue *SD, VRBaseMapType &VRBaseMap);132 133 /// Emit a DBG_VALUE from the operands to SDDbgValue.134 MachineInstr *EmitDbgValueFromSingleOp(SDDbgValue *SD,135 VRBaseMapType &VRBaseMap);136 137 /// Generate machine instruction for a dbg_label node.138 MachineInstr *EmitDbgLabel(SDDbgLabel *SD);139 140 /// EmitNode - Generate machine code for a node and needed dependencies.141 ///142 void EmitNode(SDNode *Node, bool IsClone, bool IsCloned,143 VRBaseMapType &VRBaseMap) {144 if (Node->isMachineOpcode())145 EmitMachineNode(Node, IsClone, IsCloned, VRBaseMap);146 else147 EmitSpecialNode(Node, IsClone, IsCloned, VRBaseMap);148 }149 150 /// getBlock - Return the current basic block.151 MachineBasicBlock *getBlock() { return MBB; }152 153 /// getInsertPos - Return the current insertion position.154 MachineBasicBlock::iterator getInsertPos() { return InsertPos; }155 156 /// InstrEmitter - Construct an InstrEmitter and set it to start inserting157 /// at the given position in the given block.158 InstrEmitter(const TargetMachine &TM, MachineBasicBlock *mbb,159 MachineBasicBlock::iterator insertpos);160 161private:162 void EmitMachineNode(SDNode *Node, bool IsClone, bool IsCloned,163 VRBaseMapType &VRBaseMap);164 void EmitSpecialNode(SDNode *Node, bool IsClone, bool IsCloned,165 VRBaseMapType &VRBaseMap);166};167} // namespace llvm168 169#endif170