From 135604129646650ef9abcd12a38b2d8976d3493c Mon Sep 17 00:00:00 2001 From: Bill Wendling Date: Wed, 18 Apr 2012 06:00:09 +0000 Subject: [PATCH] Use a heavy hammer to fix PR12573. If the loop contains invoke instructions, whose unwind edge escapes the loop, then don't try to unswitch the loop. Doing so may cause the unwind edge to be split, which not only is non-trivial but doesn't preserve loop simplify information. Fixes PR12573 git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@154987 91177308-0d34-0410-b5e6-96231b3b80d8 --- lib/Transforms/Scalar/LoopUnswitch.cpp | 9 +++++++++ 1 file changed, 9 insertions(+) diff --git a/lib/Transforms/Scalar/LoopUnswitch.cpp b/lib/Transforms/Scalar/LoopUnswitch.cpp index ee232687ffd..00ecc749af0 100644 --- a/lib/Transforms/Scalar/LoopUnswitch.cpp +++ b/lib/Transforms/Scalar/LoopUnswitch.cpp @@ -409,6 +409,15 @@ bool LoopUnswitch::processCurrentLoop() { if (!currentLoop->isSafeToClone()) return false; + // Loops with invokes, whose unwind edge escapes the loop, cannot be + // unswitched because splitting their edges are non-trivial and don't preserve + // loop simplify information. + for (Loop::block_iterator I = currentLoop->block_begin(), + E = currentLoop->block_end(); I != E; ++I) + if (const InvokeInst *II = dyn_cast((*I)->getTerminator())) + if (!currentLoop->contains(II->getUnwindDest())) + return false; + // Without dedicated exits, splitting the exit edge may fail. if (!currentLoop->hasDedicatedExits()) return false; -- 2.34.1