diff --git a/llvm/lib/Transforms/Utils/SimplifyCFG.cpp b/llvm/lib/Transforms/Utils/SimplifyCFG.cpp index dc56ebb08d12..7a3d368f34c1 100644 --- a/llvm/lib/Transforms/Utils/SimplifyCFG.cpp +++ b/llvm/lib/Transforms/Utils/SimplifyCFG.cpp @@ -5278,9 +5278,17 @@ bool SimplifyCFGOpt::run(BasicBlock *BB) { if ((pred_empty(BB) && BB != &BB->getParent()->getEntryBlock()) || BB->getSinglePredecessor() == BB) { - DEBUG(dbgs() << "Removing BB: \n" << *BB); - DeleteDeadBlock(BB); - return true; + // Get the block mostly empty. + Changed |= removeAllNonTerminatorAndEHPadInstructions(BB) > 0; + // Now, verify that we succeeded getting the block empty. + // This will not be the case if this unreachable BB creates a token which is + // consumed by other unreachable blocks. + Instruction *FirstNonPHI = BB->getFirstNonPHI(); + if (isa(FirstNonPHI) && FirstNonPHI->use_empty()) { + DEBUG(dbgs() << "Removing BB: \n" << *BB); + DeleteDeadBlock(BB); + return true; + } } // Check to see if we can constant propagate this terminator instruction diff --git a/llvm/test/Transforms/SimplifyCFG/unreachable-cleanuppad.ll b/llvm/test/Transforms/SimplifyCFG/unreachable-cleanuppad.ll new file mode 100644 index 000000000000..9198b2a6ea4a --- /dev/null +++ b/llvm/test/Transforms/SimplifyCFG/unreachable-cleanuppad.ll @@ -0,0 +1,40 @@ +; RUN: opt -simplifycfg -S < %s | FileCheck %s +target datalayout = "e-m:x-p:32:32-i64:64-f80:32-n8:16:32-a:0:32-S32" +target triple = "i686-pc-win32" + +declare i32 @__CxxFrameHandler3(...) + +declare void @fn_2() + +define void @fn_1(i1 %B) personality i32 (...)* @__CxxFrameHandler3 { +entry: + br i1 %B, label %__Ea.exit, label %lor.lhs.false.i.i + +lor.lhs.false.i.i: + br i1 %B, label %if.end.i.i, label %__Ea.exit + +if.end.i.i: + invoke void @fn_2() + to label %__Ea.exit unwind label %ehcleanup.i + +ehcleanup.i: + %t4 = cleanuppad within none [] + br label %arraydestroy.body.i + +arraydestroy.body.i: + %gep = getelementptr i8, i8* null, i32 -1 + br label %dtor.exit.i + +dtor.exit.i: + br i1 %B, label %arraydestroy.done3.i, label %arraydestroy.body.i + +arraydestroy.done3.i: + cleanupret from %t4 unwind to caller + +__Ea.exit: + ret void +} + +; CHECK-LABEL: define void @fn_1( +; CHECK-NEXT: entry: +; CHECK-NEXT: ret void