forked from OSchip/llvm-project
85 lines
2.5 KiB
C++
85 lines
2.5 KiB
C++
//===- TailDuplication.cpp - Duplicate blocks into predecessors' tails ----===//
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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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/// \file This pass duplicates basic blocks ending in unconditional branches
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/// into the tails of their predecessors, using the TailDuplicator utility
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/// class.
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//
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//===----------------------------------------------------------------------===//
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#include "llvm/CodeGen/MachineBranchProbabilityInfo.h"
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#include "llvm/CodeGen/MachineFunction.h"
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#include "llvm/CodeGen/MachineFunctionPass.h"
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#include "llvm/CodeGen/MachineRegisterInfo.h"
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#include "llvm/CodeGen/Passes.h"
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#include "llvm/CodeGen/TailDuplicator.h"
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#include "llvm/Pass.h"
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using namespace llvm;
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#define DEBUG_TYPE "tailduplication"
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namespace {
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class TailDuplicateBase : public MachineFunctionPass {
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TailDuplicator Duplicator;
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bool PreRegAlloc;
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public:
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TailDuplicateBase(char &PassID, bool PreRegAlloc)
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: MachineFunctionPass(PassID), PreRegAlloc(PreRegAlloc) {}
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bool runOnMachineFunction(MachineFunction &MF) override;
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void getAnalysisUsage(AnalysisUsage &AU) const override {
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AU.addRequired<MachineBranchProbabilityInfo>();
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MachineFunctionPass::getAnalysisUsage(AU);
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}
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};
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class TailDuplicate : public TailDuplicateBase {
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public:
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static char ID;
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TailDuplicate() : TailDuplicateBase(ID, false) {
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initializeTailDuplicatePass(*PassRegistry::getPassRegistry());
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}
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};
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class EarlyTailDuplicate : public TailDuplicateBase {
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public:
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static char ID;
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EarlyTailDuplicate() : TailDuplicateBase(ID, true) {
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initializeEarlyTailDuplicatePass(*PassRegistry::getPassRegistry());
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}
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};
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} // end anonymous namespace
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char TailDuplicate::ID;
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char EarlyTailDuplicate::ID;
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char &llvm::TailDuplicateID = TailDuplicate::ID;
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char &llvm::EarlyTailDuplicateID = EarlyTailDuplicate::ID;
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INITIALIZE_PASS(TailDuplicate, DEBUG_TYPE, "Tail Duplication", false, false)
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INITIALIZE_PASS(EarlyTailDuplicate, "early-tailduplication",
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"Early Tail Duplication", false, false)
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bool TailDuplicateBase::runOnMachineFunction(MachineFunction &MF) {
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if (skipFunction(MF.getFunction()))
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return false;
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auto MBPI = &getAnalysis<MachineBranchProbabilityInfo>();
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Duplicator.initMF(MF, PreRegAlloc, MBPI, /*LayoutMode=*/false);
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bool MadeChange = false;
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while (Duplicator.tailDuplicateBlocks())
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MadeChange = true;
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return MadeChange;
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}
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