1 files changed, 8 insertions, 7 deletions
diff --git a/llvm/lib/Analysis/LazyValueInfo.cpp b/llvm/lib/Analysis/LazyValueInfo.cpp
index efe878d..944b4a2 100644
--- a/llvm/lib/Analysis/LazyValueInfo.cpp
+++ b/llvm/lib/Analysis/LazyValueInfo.cpp
@@ -1662,7 +1662,7 @@ ConstantRange LazyValueInfo::getConstantRangeAtUse(const Use &U,
   // position where V can be constrained by a select or branch condition.
   const Use *CurrU = &U;
   // TODO: Increase limit?
-  const unsigned MaxUsesToInspect = 0;
+  const unsigned MaxUsesToInspect = 3;
   for (unsigned I = 0; I < MaxUsesToInspect; ++I) {
     std::optional<ValueLatticeElement> CondVal;
     auto *CurrI = cast<Instruction>(CurrU->getUser());
@@ -1675,11 +1675,6 @@ ConstantRange LazyValueInfo::getConstantRangeAtUse(const Use &U,
       // TODO: Use non-local query?
       CondVal =
           getEdgeValueLocal(V, PHI->getIncomingBlock(*CurrU), PHI->getParent());
-    } else if (!isSafeToSpeculativelyExecute(CurrI)) {
-      // Stop walking if we hit a non-speculatable instruction. Even if the
-      // result is only used under a specific condition, executing the
-      // instruction itself may cause side effects or UB already.
-      break;
     }
     if (CondVal && CondVal->isConstantRange())
       CR = CR.intersectWith(CondVal->getConstantRange());
@@ -1687,7 +1682,13 @@ ConstantRange LazyValueInfo::getConstantRangeAtUse(const Use &U,
     // Only follow one-use chain, to allow direct intersection of conditions.
     // If there are multiple uses, we would have to intersect with the union of
     // all conditions at different uses.
-    if (!CurrI->hasOneUse())
+    // Stop walking if we hit a non-speculatable instruction. Even if the
+    // result is only used under a specific condition, executing the
+    // instruction itself may cause side effects or UB already.
+    // This also disallows looking through phi nodes: If the phi node is part
+    // of a cycle, we might end up reasoning about values from different cycle
+    // iterations (PR60629).
+    if (!CurrI->hasOneUse() || !isSafeToSpeculativelyExecute(CurrI))
       break;
     CurrU = &*CurrI->use_begin();
   }