forked from OSchip/llvm-project
Fix loops where the header has an exit, fixing a loop-unswitch crash on crafty
llvm-svn: 26258
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42c9e4df6f
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@ -136,20 +136,22 @@ static bool LoopValuesUsedOutsideLoop(Loop *L) {
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static bool isTrivialLoopExitBlockHelper(Loop *L, BasicBlock *BB,
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BasicBlock *&ExitBB,
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std::set<BasicBlock*> &Visited) {
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BasicBlock *Header = L->getHeader();
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if (!Visited.insert(BB).second) {
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// Already visited and Ok, end of recursion.
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return true;
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} else if (!L->contains(BB)) {
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// Otherwise, this is a loop exit, this is fine so long as this is the
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// first exit.
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if (ExitBB != 0) return false;
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ExitBB = BB;
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return true;
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}
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// Otherwise, this is an unvisited intra-loop node. Check all successors.
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for (succ_iterator SI = succ_begin(BB), E = succ_end(BB); SI != E; ++SI) {
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if (!Visited.insert(*SI).second) {
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// Already visited and Ok, end of recursion.
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} else if (L->contains(*SI)) {
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// Check to see if the successor is a trivial loop exit.
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if (!isTrivialLoopExitBlockHelper(L, *SI, ExitBB, Visited))
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return false;
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} else {
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// Otherwise, this is a loop exit, this is fine so long as this is the
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// first exit.
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if (ExitBB != 0) return false;
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ExitBB = *SI;
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}
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// Check to see if the successor is a trivial loop exit.
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if (!isTrivialLoopExitBlockHelper(L, *SI, ExitBB, Visited))
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return false;
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}
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// Okay, everything after this looks good, check to make sure that this block
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