From 01abcf339f8d42921c680fefb2ff988cfeee1198 Mon Sep 17 00:00:00 2001 From: Frits van Bommel Date: Thu, 16 Dec 2010 12:16:00 +0000 Subject: [PATCH] Fix a bug in the loop in JumpThreading::ProcessThreadableEdges() where it could falsely produce a MultipleDestSentinel value if the first predecessor ended with an 'indirectbr'. If that happened, it caused an unnecessary FindMostPopularDest() call. This wasn't a correctness problem, but it broke the fast path for single-predecessor blocks. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@121966 91177308-0d34-0410-b5e6-96231b3b80d8 --- lib/Transforms/Scalar/JumpThreading.cpp | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/lib/Transforms/Scalar/JumpThreading.cpp b/lib/Transforms/Scalar/JumpThreading.cpp index e59ae31e13460..3d218a6585a52 100644 --- a/lib/Transforms/Scalar/JumpThreading.cpp +++ b/lib/Transforms/Scalar/JumpThreading.cpp @@ -984,7 +984,7 @@ FindMostPopularDest(BasicBlock *BB, } } - // Okay, now we know the most popular destination. If there is more than + // Okay, now we know the most popular destination. If there is more than one // destination, we need to determine one. This is arbitrary, but we need // to make a deterministic decision. Pick the first one that appears in the // successor list. @@ -1064,7 +1064,7 @@ bool JumpThreading::ProcessThreadableEdges(Value *Cond, BasicBlock *BB, } // If we have exactly one destination, remember it for efficiency below. - if (i == 0) + if (PredToDestList.empty()) OnlyDest = DestBB; else if (OnlyDest != DestBB) OnlyDest = MultipleDestSentinel;