From 5858b56ce352683909f29088cc9d9d02359f7011 Mon Sep 17 00:00:00 2001 From: Bill Wendling Date: Tue, 23 Oct 2012 18:37:11 +0000 Subject: Ignore unreachable blocks when doing memory dependence analysis on non-local loads. It's not really profitable and may result in GVN going into an infinite loop when it hits constructs like this: %x = gep %some.type %x, ... Found via an LTO build of LLVM. llvm-svn: 166490 --- llvm/lib/Analysis/MemoryDependenceAnalysis.cpp | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) (limited to 'llvm/lib/Analysis/MemoryDependenceAnalysis.cpp') diff --git a/llvm/lib/Analysis/MemoryDependenceAnalysis.cpp b/llvm/lib/Analysis/MemoryDependenceAnalysis.cpp index 9316df6fbf2..98728904945 100644 --- a/llvm/lib/Analysis/MemoryDependenceAnalysis.cpp +++ b/llvm/lib/Analysis/MemoryDependenceAnalysis.cpp @@ -983,7 +983,7 @@ getNonLocalPointerDepFromBB(const PHITransAddr &Pointer, for (NonLocalDepInfo::iterator I = Cache->begin(), E = Cache->end(); I != E; ++I) { Visited.insert(std::make_pair(I->getBB(), Addr)); - if (!I->getResult().isNonLocal()) + if (!I->getResult().isNonLocal() && DT->isReachableFromEntry(I->getBB())) Result.push_back(NonLocalDepResult(I->getBB(), I->getResult(), Addr)); } ++NumCacheCompleteNonLocalPtr; @@ -1029,7 +1029,7 @@ getNonLocalPointerDepFromBB(const PHITransAddr &Pointer, NumSortedEntries); // If we got a Def or Clobber, add this to the list of results. - if (!Dep.isNonLocal()) { + if (!Dep.isNonLocal() && DT->isReachableFromEntry(BB)) { Result.push_back(NonLocalDepResult(BB, Dep, Pointer.getAddr())); continue; } -- cgit v1.2.3