From 237d10db8c3d8677b17bb447e3504674b2d31393 Mon Sep 17 00:00:00 2001 From: Evan Cheng Date: Wed, 25 May 2011 18:17:13 +0000 Subject: [PATCH] Simplify r132022 based on Cameron's feedback. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@132071 91177308-0d34-0410-b5e6-96231b3b80d8 --- lib/Transforms/Scalar/LoopUnswitch.cpp | 17 +++++------------ 1 file changed, 5 insertions(+), 12 deletions(-) diff --git a/lib/Transforms/Scalar/LoopUnswitch.cpp b/lib/Transforms/Scalar/LoopUnswitch.cpp index a33e7956433..01a99af1439 100644 --- a/lib/Transforms/Scalar/LoopUnswitch.cpp +++ b/lib/Transforms/Scalar/LoopUnswitch.cpp @@ -919,18 +919,11 @@ void LoopUnswitch::RewriteLoopBodyWithConditionConstant(Loop *L, Value *LIC, BasicBlock *Switch = SI->getParent(); BasicBlock *SISucc = SI->getSuccessor(DeadCase); BasicBlock *Latch = L->getLoopLatch(); - // If the DeadCase successor dominates all of the predecessors of the - // loop latch, then the transformation isn't safe since it will delete - // the predecessor edges to the latch. - if (Latch) { - bool DominateAll = true; - for (pred_iterator PI = pred_begin(Latch), PE = pred_end(Latch); - DominateAll && PI != PE; ++PI) - if (!DT->dominates(SISucc, *PI)) - DominateAll = false; - if (DominateAll) - continue; - } + // If the DeadCase successor dominates the loop latch, then the + // transformation isn't safe since it will delete the sole predecessor edge + // to the latch. + if (Latch && DT->dominates(SISucc, Latch)) + continue; // FIXME: This is a hack. We need to keep the successor around // and hooked up so as to preserve the loop structure, because