1 files changed, 8 insertions, 7 deletions
diff --git a/lib/Analysis/ScalarEvolution.cpp b/lib/Analysis/ScalarEvolution.cpp
index 0c0ceeb..205227c 100644
--- a/lib/Analysis/ScalarEvolution.cpp
+++ b/lib/Analysis/ScalarEvolution.cpp
@@ -3261,9 +3261,8 @@ ScalarEvolution::GetMinTrailingZeros(const SCEV *S) {
   if (const SCEVUnknown *U = dyn_cast<SCEVUnknown>(S)) {
     // For a SCEVUnknown, ask ValueTracking.
     unsigned BitWidth = getTypeSizeInBits(U->getType());
-    APInt Mask = APInt::getAllOnesValue(BitWidth);
     APInt Zeros(BitWidth, 0), Ones(BitWidth, 0);
-    ComputeMaskedBits(U->getValue(), Mask, Zeros, Ones);
+    ComputeMaskedBits(U->getValue(), Zeros, Ones);
     return Zeros.countTrailingOnes();
   }
 
@@ -3401,9 +3400,8 @@ ScalarEvolution::getUnsignedRange(const SCEV *S) {
 
   if (const SCEVUnknown *U = dyn_cast<SCEVUnknown>(S)) {
     // For a SCEVUnknown, ask ValueTracking.
-    APInt Mask = APInt::getAllOnesValue(BitWidth);
     APInt Zeros(BitWidth, 0), Ones(BitWidth, 0);
-    ComputeMaskedBits(U->getValue(), Mask, Zeros, Ones, TD);
+    ComputeMaskedBits(U->getValue(), Zeros, Ones, TD);
     if (Ones == ~Zeros + 1)
       return setUnsignedRange(U, ConservativeResult);
     return setUnsignedRange(U,
@@ -3660,9 +3658,8 @@ const SCEV *ScalarEvolution::createSCEV(Value *V) {
       // knew about to reconstruct a low-bits mask value.
       unsigned LZ = A.countLeadingZeros();
       unsigned BitWidth = A.getBitWidth();
-      APInt AllOnes = APInt::getAllOnesValue(BitWidth);
       APInt KnownZero(BitWidth, 0), KnownOne(BitWidth, 0);
-      ComputeMaskedBits(U->getOperand(0), AllOnes, KnownZero, KnownOne, TD);
+      ComputeMaskedBits(U->getOperand(0), KnownZero, KnownOne, TD);
 
       APInt EffectiveMask = APInt::getLowBitsSet(BitWidth, BitWidth - LZ);
 
@@ -4619,6 +4616,10 @@ ScalarEvolution::ComputeLoadConstantCompareExitLimit(
       Indexes.push_back(0);
     }
 
+  // Loop-invariant loads may be a byproduct of loop optimization. Skip them.
+  if (!VarIdx)
+    return getCouldNotCompute();
+
   // Okay, we know we have a (load (gep GV, 0, X)) comparison with a constant.
   // Check to see if X is a loop variant variable value now.
   const SCEV *Idx = getSCEV(VarIdx);
@@ -6845,7 +6846,7 @@ ScalarEvolution::computeBlockDisposition(const SCEV *S, const BasicBlock *BB) {
     return ProperlyDominatesBlock;
   case scCouldNotCompute:
     llvm_unreachable("Attempt to use a SCEVCouldNotCompute object!");
-  default: 
+  default:
     llvm_unreachable("Unknown SCEV kind!");
   }
 }