5 files changed, 26 insertions, 20 deletions
diff --git a/llvm/lib/Analysis/ConstantFolding.cpp b/llvm/lib/Analysis/ConstantFolding.cpp
index f73890d548f0..cc1ce4c65821 100644
--- a/llvm/lib/Analysis/ConstantFolding.cpp
+++ b/llvm/lib/Analysis/ConstantFolding.cpp
@@ -1808,19 +1808,6 @@ double getValueAsDouble(ConstantFP *Op) {
   return APF.convertToDouble();
 }
 
-static bool isManifestConstant(const Constant *c) {
-  if (isa<ConstantData>(c)) {
-    return true;
-  } else if (isa<ConstantAggregate>(c) || isa<ConstantExpr>(c)) {
-    for (const Value *subc : c->operand_values()) {
-      if (!isManifestConstant(cast<Constant>(subc)))
-        return false;
-    }
-    return true;
-  }
-  return false;
-}
-
 static bool getConstIntOrUndef(Value *Op, const APInt *&C) {
   if (auto *CI = dyn_cast<ConstantInt>(Op)) {
     C = &CI->getValue();
@@ -1845,7 +1832,7 @@ static Constant *ConstantFoldScalarCall1(StringRef Name,
     // We know we have a "Constant" argument. But we want to only
     // return true for manifest constants, not those that depend on
     // constants with unknowable values, e.g. GlobalValue or BlockAddress.
-    if (isManifestConstant(Operands[0]))
+    if (Operands[0]->isManifestConstant())
       return ConstantInt::getTrue(Ty->getContext());
     return nullptr;
   }
diff --git a/llvm/lib/Analysis/InstructionSimplify.cpp b/llvm/lib/Analysis/InstructionSimplify.cpp
index c40e5c36cdc7..a12816885c40 100644
--- a/llvm/lib/Analysis/InstructionSimplify.cpp
+++ b/llvm/lib/Analysis/InstructionSimplify.cpp
@@ -4127,10 +4127,12 @@ static Value *simplifySelectWithICmpCond(Value *CondVal, Value *TrueVal,
                                               TrueVal, FalseVal))
     return V;
 
-  // If we have an equality comparison, then we know the value in one of the
-  // arms of the select. See if substituting this value into the arm and
+  // If we have a scalar equality comparison, then we know the value in one of
+  // the arms of the select. See if substituting this value into the arm and
   // simplifying the result yields the same value as the other arm.
-  if (Pred == ICmpInst::ICMP_EQ) {
+  // Note that the equivalence/replacement opportunity does not hold for vectors
+  // because each element of a vector select is chosen independently.
+  if (Pred == ICmpInst::ICMP_EQ && !CondVal->getType()->isVectorTy()) {
     if (SimplifyWithOpReplaced(FalseVal, CmpLHS, CmpRHS, Q,
                                /* AllowRefinement */ false, MaxRecurse) ==
             TrueVal ||
diff --git a/llvm/lib/Analysis/MemoryDependenceAnalysis.cpp b/llvm/lib/Analysis/MemoryDependenceAnalysis.cpp
index 895936d47175..886b5bf4acd3 100644
--- a/llvm/lib/Analysis/MemoryDependenceAnalysis.cpp
+++ b/llvm/lib/Analysis/MemoryDependenceAnalysis.cpp
@@ -344,7 +344,9 @@ MemoryDependenceResults::getInvariantGroupPointerDependency(LoadInst *LI,
       // If we hit load/store with the same invariant.group metadata (and the
       // same pointer operand) we can assume that value pointed by pointer
       // operand didn't change.
-      if ((isa<LoadInst>(U) || isa<StoreInst>(U)) &&
+      if ((isa<LoadInst>(U) ||
+           (isa<StoreInst>(U) &&
+            cast<StoreInst>(U)->getPointerOperand() == Ptr)) &&
           U->hasMetadata(LLVMContext::MD_invariant_group))
         ClosestDependency = GetClosestDependency(ClosestDependency, U);
     }
diff --git a/llvm/lib/Analysis/ScalarEvolution.cpp b/llvm/lib/Analysis/ScalarEvolution.cpp
index fe9d8297d679..1a9ae68573e9 100644
--- a/llvm/lib/Analysis/ScalarEvolution.cpp
+++ b/llvm/lib/Analysis/ScalarEvolution.cpp
@@ -10622,6 +10622,10 @@ bool ScalarEvolution::isImpliedViaMerge(ICmpInst::Predicate Pred,
       if (!dominates(RHS, IncBB))
         return false;
       const SCEV *L = getSCEV(LPhi->getIncomingValueForBlock(IncBB));
+      // Make sure L does not refer to a value from a potentially previous
+      // iteration of a loop.
+      if (!properlyDominates(L, IncBB))
+        return false;
       if (!ProvedEasily(L, RHS))
         return false;
     }
diff --git a/llvm/lib/Analysis/ValueTracking.cpp b/llvm/lib/Analysis/ValueTracking.cpp
index e174c5efe424..75486d3c80e7 100644
--- a/llvm/lib/Analysis/ValueTracking.cpp
+++ b/llvm/lib/Analysis/ValueTracking.cpp
@@ -5150,6 +5150,9 @@ static bool programUndefinedIfUndefOrPoison(const Value *V,
     return false;
   }
 
+  // Limit number of instructions we look at, to avoid scanning through large
+  // blocks. The current limit is chosen arbitrarily.
+  unsigned ScanLimit = 32;
   BasicBlock::const_iterator End = BB->end();
 
   if (!PoisonOnly) {
@@ -5160,6 +5163,11 @@ static bool programUndefinedIfUndefOrPoison(const Value *V,
     // For example, 'udiv x, (undef | 1)' isn't UB.
 
     for (auto &I : make_range(Begin, End)) {
+      if (isa<DbgInfoIntrinsic>(I))
+        continue;
+      if (--ScanLimit == 0)
+        break;
+
       if (const auto *CB = dyn_cast<CallBase>(&I)) {
         for (unsigned i = 0; i < CB->arg_size(); ++i) {
           if (CB->paramHasAttr(i, Attribute::NoUndef) &&
@@ -5186,9 +5194,12 @@ static bool programUndefinedIfUndefOrPoison(const Value *V,
   for_each(V->users(), Propagate);
   Visited.insert(BB);
 
-  unsigned Iter = 0;
-  while (Iter++ < MaxAnalysisRecursionDepth) {
+  while (true) {
     for (auto &I : make_range(Begin, End)) {
+      if (isa<DbgInfoIntrinsic>(I))
+        continue;
+      if (--ScanLimit == 0)
+        return false;
       if (mustTriggerUB(&I, YieldsPoison))
         return true;
       if (!isGuaranteedToTransferExecutionToSuccessor(&I))