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-rw-r--r--llvm/lib/Analysis/ScalarEvolution.cpp40
1 files changed, 0 insertions, 40 deletions
diff --git a/llvm/lib/Analysis/ScalarEvolution.cpp b/llvm/lib/Analysis/ScalarEvolution.cpp
index 26b468013c6..4e713fb1218 100644
--- a/llvm/lib/Analysis/ScalarEvolution.cpp
+++ b/llvm/lib/Analysis/ScalarEvolution.cpp
@@ -6686,46 +6686,6 @@ ScalarEvolution::isLoopBackedgeGuardedByCond(const Loop *L,
LoopContinuePredicate->getSuccessor(0) != L->getHeader()))
return true;
- // If the loop is not reachable from the entry block, we risk running into an
- // infinite loop as we walk up into the dom tree. These loops do not matter
- // anyway, so we just return a conservative answer when we see them.
- if (!DT->isReachableFromEntry(L->getHeader()))
- return false;
-
- for (DomTreeNode *DTN = (*DT)[Latch], *HeaderDTN = (*DT)[L->getHeader()];
- DTN != HeaderDTN;
- DTN = DTN->getIDom()) {
-
- assert(DTN && "should reach the loop header before reaching the root!");
-
- BasicBlock *BB = DTN->getBlock();
- BasicBlock *PBB = BB->getSinglePredecessor();
- if (!PBB)
- continue;
-
- BranchInst *ContinuePredicate = dyn_cast<BranchInst>(PBB->getTerminator());
- if (!ContinuePredicate || !ContinuePredicate->isConditional())
- continue;
-
- Value *Condition = ContinuePredicate->getCondition();
-
- // If we have an edge `E` within the loop body that dominates the only
- // latch, the condition guarding `E` also guards the backedge. This
- // reasoning works only for loops with a single latch.
-
- BasicBlockEdge DominatingEdge(PBB, BB);
- if (DominatingEdge.isSingleEdge()) {
- // We're constructively (and conservatively) enumerating edges within the
- // loop body that dominate the latch. The dominator tree better agree
- // with us on this:
- assert(DT->dominates(DominatingEdge, Latch) && "should be!");
-
- if (isImpliedCond(Pred, LHS, RHS, Condition,
- BB != ContinuePredicate->getSuccessor(0)))
- return true;
- }
- }
-
// Check conditions due to any @llvm.assume intrinsics.
for (auto &AssumeVH : AC->assumptions()) {
if (!AssumeVH)
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