From 52252fe20d5f28c07a69633276a3dde506cc0cce Mon Sep 17 00:00:00 2001 From: Balaram Makam Date: Wed, 25 Oct 2017 21:32:54 +0000 Subject: [PATCH] Revert r316582 [Local] Fix a bug in the domtree update logic for MergeBasicBlockIntoOnlyPred. Summary: This reverts commit r316582. It looks like this commit broke tests on one buildbot: http://lab.llvm.org:8011/builders/llvm-clang-x86_64-expensive-checks-win/builds/5719 . . . Failing Tests (1): LLVM :: Transforms/CalledValuePropagation/simple-arguments.ll Reviewers: Subscribers: llvm-svn: 316612 --- llvm/lib/Transforms/Utils/Local.cpp | 10 +++---- llvm/unittests/Transforms/Utils/Local.cpp | 45 ------------------------------- 2 files changed, 3 insertions(+), 52 deletions(-) diff --git a/llvm/lib/Transforms/Utils/Local.cpp b/llvm/lib/Transforms/Utils/Local.cpp index 8c643c9..fd33677 100644 --- a/llvm/lib/Transforms/Utils/Local.cpp +++ b/llvm/lib/Transforms/Utils/Local.cpp @@ -649,13 +649,9 @@ void llvm::MergeBasicBlockIntoOnlyPred(BasicBlock *DestBB, DominatorTree *DT) { DestBB->moveAfter(PredBB); if (DT) { - // For some irreducible CFG we end up having forward-unreachable blocks - // so check if getNode returns a valid node before updating the domtree. - if (DomTreeNode *DTN = DT->getNode(PredBB)) { - BasicBlock *PredBBIDom = DTN->getIDom()->getBlock(); - DT->changeImmediateDominator(DestBB, PredBBIDom); - DT->eraseNode(PredBB); - } + BasicBlock *PredBBIDom = DT->getNode(PredBB)->getIDom()->getBlock(); + DT->changeImmediateDominator(DestBB, PredBBIDom); + DT->eraseNode(PredBB); } // Nuke BB. PredBB->eraseFromParent(); diff --git a/llvm/unittests/Transforms/Utils/Local.cpp b/llvm/unittests/Transforms/Utils/Local.cpp index ee864e6..1f58dc8 100644 --- a/llvm/unittests/Transforms/Utils/Local.cpp +++ b/llvm/unittests/Transforms/Utils/Local.cpp @@ -166,48 +166,3 @@ TEST(Local, ReplaceDbgDeclare) { Declares++; EXPECT_EQ(2, Declares); } - -/// Build the dominator tree for the function and run the Test. -static void runWithDomTree( - Module &M, StringRef FuncName, - function_ref Test) { - auto *F = M.getFunction(FuncName); - ASSERT_NE(F, nullptr) << "Could not find " << FuncName; - // Compute the dominator tree for the function. - DominatorTree DT(*F); - Test(*F, &DT); -} - -TEST(Local, MergeBasicBlockIntoOnlyPred) { - LLVMContext C; - - std::unique_ptr M = parseIR( - C, - "define i32 @f(i8* %str) {\n" - "entry:\n" - " br label %bb2.i\n" - "bb2.i: ; preds = %bb4.i, %entry\n" - " br i1 false, label %bb4.i, label %base2flt.exit204\n" - "bb4.i: ; preds = %bb2.i\n" - " br i1 false, label %base2flt.exit204, label %bb2.i\n" - "bb10.i196.bb7.i197_crit_edge: ; No predecessors!\n" - " br label %bb7.i197\n" - "bb7.i197: ; preds = %bb10.i196.bb7.i197_crit_edge\n" - " %.reg2mem.0 = phi i32 [ %.reg2mem.0, %bb10.i196.bb7.i197_crit_edge ]\n" - " br i1 undef, label %base2flt.exit204, label %base2flt.exit204\n" - "base2flt.exit204: ; preds = %bb7.i197, %bb7.i197, %bb2.i, %bb4.i\n" - " ret i32 0\n" - "}\n"); - runWithDomTree( - *M, "f", [&](Function &F, DominatorTree *DT) { - for (Function::iterator I = F.begin(), E = F.end(); I != E;) { - BasicBlock *BB = &*I++; - BasicBlock *SinglePred = BB->getSinglePredecessor(); - if (!SinglePred || SinglePred == BB || BB->hasAddressTaken()) continue; - BranchInst *Term = dyn_cast(SinglePred->getTerminator()); - if (Term && !Term->isConditional()) - MergeBasicBlockIntoOnlyPred(BB, DT); - } - EXPECT_TRUE(DT->verify()); - }); -} -- 2.7.4