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Remove ADCE's ability to delete loops. This ability is now implemented in a
safer manner by loop deletion. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@51182 91177308-0d34-0410-b5e6-96231b3b80d8
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@ -191,10 +191,18 @@ bool ADCE::doADCE() {
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// be eliminated later, along with the instructions inside.
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//
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std::set<BasicBlock*> ReachableBBs;
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for (df_ext_iterator<BasicBlock*>
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BBI = df_ext_begin(&Func->front(), ReachableBBs),
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BBE = df_ext_end(&Func->front(), ReachableBBs); BBI != BBE; ++BBI) {
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BasicBlock *BB = *BBI;
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std::vector<BasicBlock*> Stack;
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Stack.push_back(&Func->getEntryBlock());
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while (!Stack.empty()) {
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BasicBlock* BB = Stack.back();
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if (ReachableBBs.count(BB)) {
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Stack.pop_back();
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continue;
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} else {
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ReachableBBs.insert(BB);
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}
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for (BasicBlock::iterator II = BB->begin(), EI = BB->end(); II != EI; ) {
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Instruction *I = II++;
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if (CallInst *CI = dyn_cast<CallInst>(I)) {
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@ -217,6 +225,15 @@ bool ADCE::doADCE() {
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++NumInstRemoved;
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}
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}
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for (succ_iterator SI = succ_begin(BB), SE = succ_end(BB); SI != SE; ++SI) {
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// Back edges (as opposed to cross edges) indicate loops, so implicitly
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// mark them live.
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if (std::find(Stack.begin(), Stack.end(), *SI) != Stack.end())
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markInstructionLive(BB->getTerminator());
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if (!ReachableBBs.count(*SI))
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Stack.push_back(*SI);
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}
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}
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// Check to ensure we have an exit node for this CFG. If we don't, we won't
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