Line data    Source code

       1             : //===- llvm/CodeGen/GlobalISel/InstructionSelector.cpp --------------------===//
       2             : //
       3             : //                     The LLVM Compiler Infrastructure
       4             : //
       5             : // This file is distributed under the University of Illinois Open Source
       6             : // License. See LICENSE.TXT for details.
       7             : //
       8             : //===----------------------------------------------------------------------===//
       9             : //
      10             : /// \file
      11             : /// This file implements the InstructionSelector class.
      12             : //
      13             : //===----------------------------------------------------------------------===//
      14             : 
      15             : #include "llvm/CodeGen/GlobalISel/InstructionSelector.h"
      16             : #include "llvm/CodeGen/GlobalISel/Utils.h"
      17             : #include "llvm/CodeGen/MachineBasicBlock.h"
      18             : #include "llvm/CodeGen/MachineFunction.h"
      19             : #include "llvm/CodeGen/MachineInstr.h"
      20             : #include "llvm/CodeGen/MachineOperand.h"
      21             : #include "llvm/CodeGen/MachineRegisterInfo.h"
      22             : #include "llvm/CodeGen/TargetRegisterInfo.h"
      23             : #include "llvm/MC/MCInstrDesc.h"
      24             : #include "llvm/Support/Debug.h"
      25             : #include "llvm/Support/raw_ostream.h"
      26             : #include <cassert>
      27             : 
      28             : #define DEBUG_TYPE "instructionselector"
      29             : 
      30             : using namespace llvm;
      31             : 
      32       35702 : InstructionSelector::MatcherState::MatcherState(unsigned MaxRenderers)
      33       35702 :     : Renderers(MaxRenderers), MIs() {}
      34             : 
      35             : InstructionSelector::InstructionSelector() = default;
      36             : 
      37         308 : bool InstructionSelector::constrainOperandRegToRegClass(
      38             :     MachineInstr &I, unsigned OpIdx, const TargetRegisterClass &RC,
      39             :     const TargetInstrInfo &TII, const TargetRegisterInfo &TRI,
      40             :     const RegisterBankInfo &RBI) const {
      41         308 :   MachineBasicBlock &MBB = *I.getParent();
      42         308 :   MachineFunction &MF = *MBB.getParent();
      43         308 :   MachineRegisterInfo &MRI = MF.getRegInfo();
      44             : 
      45             :   return
      46         616 :       constrainRegToClass(MRI, TII, RBI, I, I.getOperand(OpIdx).getReg(), RC);
      47             : }
      48             : 
      49         492 : bool InstructionSelector::isOperandImmEqual(
      50             :     const MachineOperand &MO, int64_t Value,
      51             :     const MachineRegisterInfo &MRI) const {
      52         492 :   if (MO.isReg() && MO.getReg())
      53         492 :     if (auto VRegVal = getConstantVRegVal(MO.getReg(), MRI))
      54         210 :       return *VRegVal == Value;
      55             :   return false;
      56             : }
      57             : 
      58         365 : bool InstructionSelector::isBaseWithConstantOffset(
      59             :     const MachineOperand &Root, const MachineRegisterInfo &MRI) const {
      60         365 :   if (!Root.isReg())
      61             :     return false;
      62             : 
      63         365 :   MachineInstr *RootI = MRI.getVRegDef(Root.getReg());
      64         730 :   if (RootI->getOpcode() != TargetOpcode::G_GEP)
      65             :     return false;
      66             : 
      67         189 :   MachineOperand &RHS = RootI->getOperand(2);
      68         189 :   MachineInstr *RHSI = MRI.getVRegDef(RHS.getReg());
      69         378 :   if (RHSI->getOpcode() != TargetOpcode::G_CONSTANT)
      70           0 :     return false;
      71             : 
      72             :   return true;
      73             : }
      74             : 
      75         240 : bool InstructionSelector::isObviouslySafeToFold(MachineInstr &MI,
      76             :                                                 MachineInstr &IntoMI) const {
      77             :   // Immediate neighbours are already folded.
      78         480 :   if (MI.getParent() == IntoMI.getParent() &&
      79         240 :       std::next(MI.getIterator()) == IntoMI.getIterator())
      80             :     return true;
      81             : 
      82         230 :   return !MI.mayLoadOrStore() && !MI.hasUnmodeledSideEffects() &&
      83             :          MI.implicit_operands().begin() == MI.implicit_operands().end();
      84             : }