b91d9ec0bb
https://reviews.llvm.org/D67133 While investigating some non determinism (CSE doesn't produce wrong code, it just doesn't CSE some times) in GISel CSE on an out of tree target, I realized that the core issue was that there were lots of code that mutates (setReg, setRegClass etc), but doesn't notify observers (CSE in this case but this could be any other observer). In order to make the Observer be available in various parts of code and to avoid having to thread it through various API, the MachineFunction now has the observer as field. This allows it to be easily used in helper functions such as constrainOperandRegClass. Also added some invariant verification method in CSEInfo which can catch these issues (when CSE is enabled).
49 lines
1.7 KiB
C++
49 lines
1.7 KiB
C++
//===-- lib/CodeGen/GlobalISel/GISelChangeObserver.cpp --------------------===//
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//
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// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
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// See https://llvm.org/LICENSE.txt for license information.
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// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
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//
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//===----------------------------------------------------------------------===//
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//
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// This file constains common code to combine machine functions at generic
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// level.
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//===----------------------------------------------------------------------===//
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#include "llvm/CodeGen/GlobalISel/GISelChangeObserver.h"
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#include "llvm/CodeGen/MachineRegisterInfo.h"
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using namespace llvm;
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void GISelChangeObserver::changingAllUsesOfReg(
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const MachineRegisterInfo &MRI, unsigned Reg) {
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for (auto &ChangingMI : MRI.use_instructions(Reg)) {
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changingInstr(ChangingMI);
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ChangingAllUsesOfReg.insert(&ChangingMI);
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}
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}
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void GISelChangeObserver::finishedChangingAllUsesOfReg() {
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for (auto *ChangedMI : ChangingAllUsesOfReg)
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changedInstr(*ChangedMI);
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ChangingAllUsesOfReg.clear();
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}
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RAIIDelegateInstaller::RAIIDelegateInstaller(MachineFunction &MF,
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MachineFunction::Delegate *Del)
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: MF(MF), Delegate(Del) {
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// Register this as the delegate for handling insertions and deletions of
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// instructions.
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MF.setDelegate(Del);
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}
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RAIIDelegateInstaller::~RAIIDelegateInstaller() { MF.resetDelegate(Delegate); }
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RAIIMFObserverInstaller::RAIIMFObserverInstaller(MachineFunction &MF,
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GISelChangeObserver &Observer)
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: MF(MF) {
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MF.setObserver(&Observer);
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}
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RAIIMFObserverInstaller::~RAIIMFObserverInstaller() { MF.setObserver(nullptr); }
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