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7962dbdc65
definition below all of the header #include lines, lib/Transforms/... edition. This one is tricky for two reasons. We again have a couple of passes that define something else before the includes as well. I've sunk their name macros with the DEBUG_TYPE. Also, InstCombine contains headers that need DEBUG_TYPE, so now those headers #define and #undef DEBUG_TYPE around their code, leaving them well formed modular headers. Fixing these headers was a large motivation for all of these changes, as "leaky" macros of this form are hard on the modules implementation. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@206844 91177308-0d34-0410-b5e6-96231b3b80d8
81 lines
2.3 KiB
C++
81 lines
2.3 KiB
C++
//===- FlattenCFGPass.cpp - CFG Flatten Pass ----------------------===//
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//
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// The LLVM Compiler Infrastructure
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//
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// This file is distributed under the University of Illinois Open Source
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// License. See LICENSE.TXT for details.
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//
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//===----------------------------------------------------------------------===//
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//
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// This file implements flattening of CFG.
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//
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//===----------------------------------------------------------------------===//
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#include "llvm/Transforms/Scalar.h"
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#include "llvm/Analysis/AliasAnalysis.h"
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#include "llvm/IR/CFG.h"
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#include "llvm/Pass.h"
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#include "llvm/Transforms/Utils/Local.h"
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using namespace llvm;
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#define DEBUG_TYPE "flattencfg"
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namespace {
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struct FlattenCFGPass : public FunctionPass {
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static char ID; // Pass identification, replacement for typeid
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public:
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FlattenCFGPass() : FunctionPass(ID) {
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initializeFlattenCFGPassPass(*PassRegistry::getPassRegistry());
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}
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bool runOnFunction(Function &F) override;
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void getAnalysisUsage(AnalysisUsage &AU) const override {
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AU.addRequired<AliasAnalysis>();
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}
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private:
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AliasAnalysis *AA;
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};
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}
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char FlattenCFGPass::ID = 0;
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INITIALIZE_PASS_BEGIN(FlattenCFGPass, "flattencfg", "Flatten the CFG", false,
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false)
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INITIALIZE_AG_DEPENDENCY(AliasAnalysis)
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INITIALIZE_PASS_END(FlattenCFGPass, "flattencfg", "Flatten the CFG", false,
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false)
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// Public interface to the FlattenCFG pass
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FunctionPass *llvm::createFlattenCFGPass() { return new FlattenCFGPass(); }
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/// iterativelyFlattenCFG - Call FlattenCFG on all the blocks in the function,
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/// iterating until no more changes are made.
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static bool iterativelyFlattenCFG(Function &F, AliasAnalysis *AA) {
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bool Changed = false;
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bool LocalChange = true;
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while (LocalChange) {
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LocalChange = false;
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// Loop over all of the basic blocks and remove them if they are unneeded...
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//
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for (Function::iterator BBIt = F.begin(); BBIt != F.end();) {
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if (FlattenCFG(BBIt++, AA)) {
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LocalChange = true;
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}
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}
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Changed |= LocalChange;
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}
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return Changed;
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}
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bool FlattenCFGPass::runOnFunction(Function &F) {
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AA = &getAnalysis<AliasAnalysis>();
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bool EverChanged = false;
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// iterativelyFlattenCFG can make some blocks dead.
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while (iterativelyFlattenCFG(F, AA)) {
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removeUnreachableBlocks(F);
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EverChanged = true;
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}
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return EverChanged;
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}
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