| //===- llvm/CodeGen/GlobalISel/InstructionSelector.cpp --------------------===// |
| // |
| // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. |
| // See https://llvm.org/LICENSE.txt for license information. |
| // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception |
| // |
| //===----------------------------------------------------------------------===// |
| // |
| /// \file |
| /// This file implements the InstructionSelector class. |
| // |
| //===----------------------------------------------------------------------===// |
| |
| #include "llvm/CodeGen/GlobalISel/InstructionSelector.h" |
| #include "llvm/CodeGen/GlobalISel/Utils.h" |
| #include "llvm/CodeGen/MachineInstr.h" |
| #include "llvm/CodeGen/MachineOperand.h" |
| #include "llvm/CodeGen/MachineRegisterInfo.h" |
| |
| #define DEBUG_TYPE "instructionselector" |
| |
| using namespace llvm; |
| |
| InstructionSelector::MatcherState::MatcherState(unsigned MaxRenderers) |
| : Renderers(MaxRenderers) {} |
| |
| InstructionSelector::InstructionSelector() = default; |
| |
| bool InstructionSelector::isOperandImmEqual( |
| const MachineOperand &MO, int64_t Value, |
| const MachineRegisterInfo &MRI) const { |
| if (MO.isReg() && MO.getReg()) |
| if (auto VRegVal = getIConstantVRegValWithLookThrough(MO.getReg(), MRI)) |
| return VRegVal->Value.getSExtValue() == Value; |
| return false; |
| } |
| |
| bool InstructionSelector::isBaseWithConstantOffset( |
| const MachineOperand &Root, const MachineRegisterInfo &MRI) const { |
| if (!Root.isReg()) |
| return false; |
| |
| MachineInstr *RootI = MRI.getVRegDef(Root.getReg()); |
| if (RootI->getOpcode() != TargetOpcode::G_PTR_ADD) |
| return false; |
| |
| MachineOperand &RHS = RootI->getOperand(2); |
| MachineInstr *RHSI = MRI.getVRegDef(RHS.getReg()); |
| if (RHSI->getOpcode() != TargetOpcode::G_CONSTANT) |
| return false; |
| |
| return true; |
| } |
| |
| bool InstructionSelector::isObviouslySafeToFold(MachineInstr &MI, |
| MachineInstr &IntoMI) const { |
| // Immediate neighbours are already folded. |
| if (MI.getParent() == IntoMI.getParent() && |
| std::next(MI.getIterator()) == IntoMI.getIterator()) |
| return true; |
| |
| // Convergent instructions cannot be moved in the CFG. |
| if (MI.isConvergent() && MI.getParent() != IntoMI.getParent()) |
| return false; |
| |
| return !MI.mayLoadOrStore() && !MI.mayRaiseFPException() && |
| !MI.hasUnmodeledSideEffects() && MI.implicit_operands().empty(); |
| } |