diff --git a/llvm/include/llvm/CodeGen/BasicTTIImpl.h b/llvm/include/llvm/CodeGen/BasicTTIImpl.h
--- a/llvm/include/llvm/CodeGen/BasicTTIImpl.h
+++ b/llvm/include/llvm/CodeGen/BasicTTIImpl.h
@@ -935,31 +935,28 @@
                                               ArrayRef<int> Mask,
                                               VectorType *Ty, int &Index,
                                               VectorType *&SubTy) const {
-    int Limit = Mask.size() * 2;
-    if (Mask.empty() ||
-        // Extra check required by isSingleSourceMaskImpl function (called by
-        // ShuffleVectorInst::isSingleSourceMask).
-        any_of(Mask, [Limit](int I) { return I >= Limit; }))
+    if (Mask.empty())
       return Kind;
+    int NumSrcElts = Ty->getElementCount().getKnownMinValue();
     switch (Kind) {
     case TTI::SK_PermuteSingleSrc:
-      if (ShuffleVectorInst::isReverseMask(Mask))
+      if (ShuffleVectorInst::isReverseMask(Mask, NumSrcElts))
         return TTI::SK_Reverse;
-      if (ShuffleVectorInst::isZeroEltSplatMask(Mask))
+      if (ShuffleVectorInst::isZeroEltSplatMask(Mask, NumSrcElts))
         return TTI::SK_Broadcast;
       break;
     case TTI::SK_PermuteTwoSrc: {
       int NumSubElts;
       if (Mask.size() > 2 && ShuffleVectorInst::isInsertSubvectorMask(
-                                 Mask, Mask.size(), NumSubElts, Index)) {
+                                 Mask, NumSrcElts, NumSubElts, Index)) {
         SubTy = FixedVectorType::get(Ty->getElementType(), NumSubElts);
         return TTI::SK_InsertSubvector;
       }
-      if (ShuffleVectorInst::isSelectMask(Mask))
+      if (ShuffleVectorInst::isSelectMask(Mask, NumSrcElts))
         return TTI::SK_Select;
-      if (ShuffleVectorInst::isTransposeMask(Mask))
+      if (ShuffleVectorInst::isTransposeMask(Mask, NumSrcElts))
         return TTI::SK_Transpose;
-      if (ShuffleVectorInst::isSpliceMask(Mask, Index))
+      if (ShuffleVectorInst::isSpliceMask(Mask, NumSrcElts, Index))
         return TTI::SK_Splice;
       break;
     }
diff --git a/llvm/include/llvm/IR/Instructions.h b/llvm/include/llvm/IR/Instructions.h
--- a/llvm/include/llvm/IR/Instructions.h
+++ b/llvm/include/llvm/IR/Instructions.h
@@ -2068,13 +2068,14 @@
   /// Return true if this shuffle mask chooses elements from exactly one source
   /// vector.
   /// Example: <7,5,undef,7>
-  /// This assumes that vector operands are the same length as the mask.
-  static bool isSingleSourceMask(ArrayRef<int> Mask);
-  static bool isSingleSourceMask(const Constant *Mask) {
+  /// This assumes that vector operands (of length \p NumSrcElts) are the same
+  /// length as the mask.
+  static bool isSingleSourceMask(ArrayRef<int> Mask, int NumSrcElts);
+  static bool isSingleSourceMask(const Constant *Mask, int NumSrcElts) {
     assert(Mask->getType()->isVectorTy() && "Shuffle needs vector constant.");
     SmallVector<int, 16> MaskAsInts;
     getShuffleMask(Mask, MaskAsInts);
-    return isSingleSourceMask(MaskAsInts);
+    return isSingleSourceMask(MaskAsInts, NumSrcElts);
   }
 
   /// Return true if this shuffle chooses elements from exactly one source
@@ -2082,7 +2083,8 @@
   /// Example: shufflevector <4 x n> A, <4 x n> B, <3,0,undef,3>
   /// TODO: Optionally allow length-changing shuffles.
   bool isSingleSource() const {
-    return !changesLength() && isSingleSourceMask(ShuffleMask);
+    return !changesLength() &&
+           isSingleSourceMask(ShuffleMask, ShuffleMask.size());
   }
 
   /// Return true if this shuffle mask chooses elements from exactly one source
@@ -2090,8 +2092,8 @@
   /// necessarily a no-op because it may change the number of elements from its
   /// input vectors or it may provide demanded bits knowledge via undef lanes.
   /// Example: <undef,undef,2,3>
-  static bool isIdentityMask(ArrayRef<int> Mask);
-  static bool isIdentityMask(const Constant *Mask) {
+  static bool isIdentityMask(ArrayRef<int> Mask, int NumSrcElts);
+  static bool isIdentityMask(const Constant *Mask, int NumSrcElts) {
     assert(Mask->getType()->isVectorTy() && "Shuffle needs vector constant.");
 
     // Not possible to express a shuffle mask for a scalable vector for this
@@ -2101,7 +2103,7 @@
 
     SmallVector<int, 16> MaskAsInts;
     getShuffleMask(Mask, MaskAsInts);
-    return isIdentityMask(MaskAsInts);
+    return isIdentityMask(MaskAsInts, NumSrcElts);
   }
 
   /// Return true if this shuffle chooses elements from exactly one source
@@ -2114,7 +2116,7 @@
     if (isa<ScalableVectorType>(getType()))
       return false;
 
-    return !changesLength() && isIdentityMask(ShuffleMask);
+    return !changesLength() && isIdentityMask(ShuffleMask, ShuffleMask.size());
   }
 
   /// Return true if this shuffle lengthens exactly one source vector with
@@ -2138,12 +2140,12 @@
   /// In that case, the shuffle is better classified as an identity shuffle.
   /// This assumes that vector operands are the same length as the mask
   /// (a length-changing shuffle can never be equivalent to a vector select).
-  static bool isSelectMask(ArrayRef<int> Mask);
-  static bool isSelectMask(const Constant *Mask) {
+  static bool isSelectMask(ArrayRef<int> Mask, int NumSrcElts);
+  static bool isSelectMask(const Constant *Mask, int NumSrcElts) {
     assert(Mask->getType()->isVectorTy() && "Shuffle needs vector constant.");
     SmallVector<int, 16> MaskAsInts;
     getShuffleMask(Mask, MaskAsInts);
-    return isSelectMask(MaskAsInts);
+    return isSelectMask(MaskAsInts, NumSrcElts);
   }
 
   /// Return true if this shuffle chooses elements from its source vectors
@@ -2155,19 +2157,20 @@
   /// In that case, the shuffle is better classified as an identity shuffle.
   /// TODO: Optionally allow length-changing shuffles.
   bool isSelect() const {
-    return !changesLength() && isSelectMask(ShuffleMask);
+    return !changesLength() && isSelectMask(ShuffleMask, ShuffleMask.size());
   }
 
   /// Return true if this shuffle mask swaps the order of elements from exactly
   /// one source vector.
   /// Example: <7,6,undef,4>
-  /// This assumes that vector operands are the same length as the mask.
-  static bool isReverseMask(ArrayRef<int> Mask);
-  static bool isReverseMask(const Constant *Mask) {
+  /// This assumes that vector operands (of length \p NumSrcElts) are the same
+  /// length as the mask.
+  static bool isReverseMask(ArrayRef<int> Mask, int NumSrcElts);
+  static bool isReverseMask(const Constant *Mask, int NumSrcElts) {
     assert(Mask->getType()->isVectorTy() && "Shuffle needs vector constant.");
     SmallVector<int, 16> MaskAsInts;
     getShuffleMask(Mask, MaskAsInts);
-    return isReverseMask(MaskAsInts);
+    return isReverseMask(MaskAsInts, NumSrcElts);
   }
 
   /// Return true if this shuffle swaps the order of elements from exactly
@@ -2175,19 +2178,20 @@
   /// Example: shufflevector <4 x n> A, <4 x n> B, <3,undef,1,undef>
   /// TODO: Optionally allow length-changing shuffles.
   bool isReverse() const {
-    return !changesLength() && isReverseMask(ShuffleMask);
+    return !changesLength() && isReverseMask(ShuffleMask, ShuffleMask.size());
   }
 
   /// Return true if this shuffle mask chooses all elements with the same value
   /// as the first element of exactly one source vector.
   /// Example: <4,undef,undef,4>
-  /// This assumes that vector operands are the same length as the mask.
-  static bool isZeroEltSplatMask(ArrayRef<int> Mask);
-  static bool isZeroEltSplatMask(const Constant *Mask) {
+  /// This assumes that vector operands (of length \p NumSrcElts) are the same
+  /// length as the mask.
+  static bool isZeroEltSplatMask(ArrayRef<int> Mask, int NumSrcElts);
+  static bool isZeroEltSplatMask(const Constant *Mask, int NumSrcElts) {
     assert(Mask->getType()->isVectorTy() && "Shuffle needs vector constant.");
     SmallVector<int, 16> MaskAsInts;
     getShuffleMask(Mask, MaskAsInts);
-    return isZeroEltSplatMask(MaskAsInts);
+    return isZeroEltSplatMask(MaskAsInts, NumSrcElts);
   }
 
   /// Return true if all elements of this shuffle are the same value as the
@@ -2197,7 +2201,8 @@
   /// TODO: Optionally allow length-changing shuffles.
   /// TODO: Optionally allow splats from other elements.
   bool isZeroEltSplat() const {
-    return !changesLength() && isZeroEltSplatMask(ShuffleMask);
+    return !changesLength() &&
+           isZeroEltSplatMask(ShuffleMask, ShuffleMask.size());
   }
 
   /// Return true if this shuffle mask is a transpose mask.
@@ -2232,12 +2237,12 @@
   ///   ; Transposed matrix
   ///   t0 = < a, e, c, g > = shufflevector m0, m1 < 0, 4, 2, 6 >
   ///   t1 = < b, f, d, h > = shufflevector m0, m1 < 1, 5, 3, 7 >
-  static bool isTransposeMask(ArrayRef<int> Mask);
-  static bool isTransposeMask(const Constant *Mask) {
+  static bool isTransposeMask(ArrayRef<int> Mask, int NumSrcElts);
+  static bool isTransposeMask(const Constant *Mask, int NumSrcElts) {
     assert(Mask->getType()->isVectorTy() && "Shuffle needs vector constant.");
     SmallVector<int, 16> MaskAsInts;
     getShuffleMask(Mask, MaskAsInts);
-    return isTransposeMask(MaskAsInts);
+    return isTransposeMask(MaskAsInts, NumSrcElts);
   }
 
   /// Return true if this shuffle transposes the elements of its inputs without
@@ -2246,19 +2251,21 @@
   /// exact specification.
   /// Example: shufflevector <4 x n> A, <4 x n> B, <0,4,2,6>
   bool isTranspose() const {
-    return !changesLength() && isTransposeMask(ShuffleMask);
+    return !changesLength() && isTransposeMask(ShuffleMask, ShuffleMask.size());
   }
 
   /// Return true if this shuffle mask is a splice mask, concatenating the two
   /// inputs together and then extracts an original width vector starting from
   /// the splice index.
   /// Example: shufflevector <4 x n> A, <4 x n> B, <1,2,3,4>
-  static bool isSpliceMask(ArrayRef<int> Mask, int &Index);
-  static bool isSpliceMask(const Constant *Mask, int &Index) {
+  /// This assumes that vector operands (of length \p NumSrcElts) are the same
+  /// length as the mask.
+  static bool isSpliceMask(ArrayRef<int> Mask, int NumSrcElts, int &Index);
+  static bool isSpliceMask(const Constant *Mask, int NumSrcElts, int &Index) {
     assert(Mask->getType()->isVectorTy() && "Shuffle needs vector constant.");
     SmallVector<int, 16> MaskAsInts;
     getShuffleMask(Mask, MaskAsInts);
-    return isSpliceMask(MaskAsInts, Index);
+    return isSpliceMask(MaskAsInts, NumSrcElts, Index);
   }
 
   /// Return true if this shuffle splices two inputs without changing the length
@@ -2266,7 +2273,8 @@
   /// then extracts an original width vector starting from the splice index.
   /// Example: shufflevector <4 x n> A, <4 x n> B, <1,2,3,4>
   bool isSplice(int &Index) const {
-    return !changesLength() && isSpliceMask(ShuffleMask, Index);
+    return !changesLength() &&
+           isSpliceMask(ShuffleMask, ShuffleMask.size(), Index);
   }
 
   /// Return true if this shuffle mask is an extract subvector mask.
diff --git a/llvm/lib/CodeGen/SelectionDAG/DAGCombiner.cpp b/llvm/lib/CodeGen/SelectionDAG/DAGCombiner.cpp
--- a/llvm/lib/CodeGen/SelectionDAG/DAGCombiner.cpp
+++ b/llvm/lib/CodeGen/SelectionDAG/DAGCombiner.cpp
@@ -24119,7 +24119,7 @@
 
   // Profitability check: only deal with extractions from the first subvector
   // unless the mask becomes an identity mask.
-  if (!ShuffleVectorInst::isIdentityMask(NewMask) ||
+  if (!ShuffleVectorInst::isIdentityMask(NewMask, NewMask.size()) ||
       any_of(NewMask, [](int M) { return M < 0; }))
     for (auto &DemandedSubvector : DemandedSubvectors)
       if (DemandedSubvector.second != 0)
diff --git a/llvm/lib/IR/Instructions.cpp b/llvm/lib/IR/Instructions.cpp
--- a/llvm/lib/IR/Instructions.cpp
+++ b/llvm/lib/IR/Instructions.cpp
@@ -2136,10 +2136,10 @@
   return UsesLHS || UsesRHS;
 }
 
-bool ShuffleVectorInst::isSingleSourceMask(ArrayRef<int> Mask) {
+bool ShuffleVectorInst::isSingleSourceMask(ArrayRef<int> Mask, int NumSrcElts) {
   // We don't have vector operand size information, so assume operands are the
   // same size as the mask.
-  return isSingleSourceMaskImpl(Mask, Mask.size());
+  return isSingleSourceMaskImpl(Mask, NumSrcElts);
 }
 
 static bool isIdentityMaskImpl(ArrayRef<int> Mask, int NumOpElts) {
@@ -2154,65 +2154,75 @@
   return true;
 }
 
-bool ShuffleVectorInst::isIdentityMask(ArrayRef<int> Mask) {
+bool ShuffleVectorInst::isIdentityMask(ArrayRef<int> Mask, int NumSrcElts) {
+  if (Mask.size() != static_cast<unsigned>(NumSrcElts))
+    return false;
   // We don't have vector operand size information, so assume operands are the
   // same size as the mask.
-  return isIdentityMaskImpl(Mask, Mask.size());
+  return isIdentityMaskImpl(Mask, NumSrcElts);
 }
 
-bool ShuffleVectorInst::isReverseMask(ArrayRef<int> Mask) {
-  if (!isSingleSourceMask(Mask))
+bool ShuffleVectorInst::isReverseMask(ArrayRef<int> Mask, int NumSrcElts) {
+  if (Mask.size() != static_cast<unsigned>(NumSrcElts))
+    return false;
+  if (!isSingleSourceMask(Mask, NumSrcElts))
     return false;
 
   // The number of elements in the mask must be at least 2.
-  int NumElts = Mask.size();
-  if (NumElts < 2)
+  if (NumSrcElts < 2)
     return false;
 
-  for (int i = 0; i < NumElts; ++i) {
-    if (Mask[i] == -1)
+  for (int I = 0, E = Mask.size(); I < E; ++I) {
+    if (Mask[I] == -1)
       continue;
-    if (Mask[i] != (NumElts - 1 - i) && Mask[i] != (NumElts + NumElts - 1 - i))
+    if (Mask[I] != (NumSrcElts - 1 - I) &&
+        Mask[I] != (NumSrcElts + NumSrcElts - 1 - I))
       return false;
   }
   return true;
 }
 
-bool ShuffleVectorInst::isZeroEltSplatMask(ArrayRef<int> Mask) {
-  if (!isSingleSourceMask(Mask))
+bool ShuffleVectorInst::isZeroEltSplatMask(ArrayRef<int> Mask, int NumSrcElts) {
+  if (Mask.size() != static_cast<unsigned>(NumSrcElts))
     return false;
-  for (int i = 0, NumElts = Mask.size(); i < NumElts; ++i) {
-    if (Mask[i] == -1)
+  if (!isSingleSourceMask(Mask, NumSrcElts))
+    return false;
+  for (int I = 0, E = Mask.size(); I < E; ++I) {
+    if (Mask[I] == -1)
       continue;
-    if (Mask[i] != 0 && Mask[i] != NumElts)
+    if (Mask[I] != 0 && Mask[I] != NumSrcElts)
       return false;
   }
   return true;
 }
 
-bool ShuffleVectorInst::isSelectMask(ArrayRef<int> Mask) {
+bool ShuffleVectorInst::isSelectMask(ArrayRef<int> Mask, int NumSrcElts) {
+  if (Mask.size() != static_cast<unsigned>(NumSrcElts))
+    return false;
   // Select is differentiated from identity. It requires using both sources.
-  if (isSingleSourceMask(Mask))
+  if (isSingleSourceMask(Mask, NumSrcElts))
     return false;
-  for (int i = 0, NumElts = Mask.size(); i < NumElts; ++i) {
-    if (Mask[i] == -1)
+  for (int I = 0, E = Mask.size(); I < E; ++I) {
+    if (Mask[I] == -1)
       continue;
-    if (Mask[i] != i && Mask[i] != (NumElts + i))
+    if (Mask[I] != I && Mask[I] != (NumSrcElts + I))
       return false;
   }
   return true;
 }
 
-bool ShuffleVectorInst::isTransposeMask(ArrayRef<int> Mask) {
+bool ShuffleVectorInst::isTransposeMask(ArrayRef<int> Mask, int NumSrcElts) {
   // Example masks that will return true:
   // v1 = <a, b, c, d>
   // v2 = <e, f, g, h>
   // trn1 = shufflevector v1, v2 <0, 4, 2, 6> = <a, e, c, g>
   // trn2 = shufflevector v1, v2 <1, 5, 3, 7> = <b, f, d, h>
 
+  if (Mask.size() != static_cast<unsigned>(NumSrcElts))
+    return false;
   // 1. The number of elements in the mask must be a power-of-2 and at least 2.
-  int NumElts = Mask.size();
-  if (NumElts < 2 || !isPowerOf2_32(NumElts))
+  int Sz = Mask.size();
+  if (Sz < 2 || !isPowerOf2_32(Sz))
     return false;
 
   // 2. The first element of the mask must be either a 0 or a 1.
@@ -2221,23 +2231,26 @@
 
   // 3. The difference between the first 2 elements must be equal to the
   // number of elements in the mask.
-  if ((Mask[1] - Mask[0]) != NumElts)
+  if ((Mask[1] - Mask[0]) != NumSrcElts)
     return false;
 
   // 4. The difference between consecutive even-numbered and odd-numbered
   // elements must be equal to 2.
-  for (int i = 2; i < NumElts; ++i) {
-    int MaskEltVal = Mask[i];
+  for (int I = 2; I < Sz; ++I) {
+    int MaskEltVal = Mask[I];
     if (MaskEltVal == -1)
       return false;
-    int MaskEltPrevVal = Mask[i - 2];
+    int MaskEltPrevVal = Mask[I - 2];
     if (MaskEltVal - MaskEltPrevVal != 2)
       return false;
   }
   return true;
 }
 
-bool ShuffleVectorInst::isSpliceMask(ArrayRef<int> Mask, int &Index) {
+bool ShuffleVectorInst::isSpliceMask(ArrayRef<int> Mask, int NumSrcElts,
+                                     int &Index) {
+  if (Mask.size() != static_cast<unsigned>(NumSrcElts))
+    return false;
   // Example: shufflevector <4 x n> A, <4 x n> B, <1,2,3,4>
   int StartIndex = -1;
   for (int I = 0, E = Mask.size(); I != E; ++I) {
@@ -2248,7 +2261,7 @@
     if (StartIndex == -1) {
       // Don't support a StartIndex that begins in the second input, or if the
       // first non-undef index would access below the StartIndex.
-      if (MaskEltVal < I || E <= (MaskEltVal - I))
+      if (MaskEltVal < I || NumSrcElts <= (MaskEltVal - I))
         return false;
 
       StartIndex = MaskEltVal - I;
@@ -2543,7 +2556,7 @@
   // case.
   if (isa<ScalableVectorType>(getType()))
     return false;
-  if (!isSingleSourceMask(ShuffleMask))
+  if (!isSingleSourceMask(ShuffleMask, VF))
     return false;
 
   return isOneUseSingleSourceMask(ShuffleMask, VF);
diff --git a/llvm/lib/Target/AArch64/AArch64ISelLowering.cpp b/llvm/lib/Target/AArch64/AArch64ISelLowering.cpp
--- a/llvm/lib/Target/AArch64/AArch64ISelLowering.cpp
+++ b/llvm/lib/Target/AArch64/AArch64ISelLowering.cpp
@@ -11802,7 +11802,7 @@
 
   if (((VT.getVectorNumElements() == 8 && VT.getScalarSizeInBits() == 16) ||
        (VT.getVectorNumElements() == 16 && VT.getScalarSizeInBits() == 8)) &&
-      ShuffleVectorInst::isReverseMask(ShuffleMask)) {
+      ShuffleVectorInst::isReverseMask(ShuffleMask, ShuffleMask.size())) {
     SDValue Rev = DAG.getNode(AArch64ISD::REV64, dl, VT, V1);
     return DAG.getNode(AArch64ISD::EXT, dl, VT, Rev, Rev,
                        DAG.getConstant(8, dl, MVT::i32));
@@ -25946,7 +25946,8 @@
   unsigned MinSVESize = Subtarget->getMinSVEVectorSizeInBits();
   unsigned MaxSVESize = Subtarget->getMaxSVEVectorSizeInBits();
   if (MinSVESize == MaxSVESize && MaxSVESize == VT.getSizeInBits()) {
-    if (ShuffleVectorInst::isReverseMask(ShuffleMask) && Op2.isUndef()) {
+    if (ShuffleVectorInst::isReverseMask(ShuffleMask, ShuffleMask.size()) &&
+        Op2.isUndef()) {
       Op = DAG.getNode(ISD::VECTOR_REVERSE, DL, ContainerVT, Op1);
       return convertFromScalableVector(DAG, VT, Op);
     }
diff --git a/llvm/lib/Target/ARM/ARMISelLowering.cpp b/llvm/lib/Target/ARM/ARMISelLowering.cpp
--- a/llvm/lib/Target/ARM/ARMISelLowering.cpp
+++ b/llvm/lib/Target/ARM/ARMISelLowering.cpp
@@ -8375,7 +8375,7 @@
   unsigned EltSize = VT.getScalarSizeInBits();
   if (EltSize >= 32 ||
       ShuffleVectorSDNode::isSplatMask(&M[0], VT) ||
-      ShuffleVectorInst::isIdentityMask(M) ||
+      ShuffleVectorInst::isIdentityMask(M, M.size()) ||
       isVREVMask(M, VT, 64) ||
       isVREVMask(M, VT, 32) ||
       isVREVMask(M, VT, 16))
diff --git a/llvm/lib/Target/RISCV/RISCVISelLowering.cpp b/llvm/lib/Target/RISCV/RISCVISelLowering.cpp
--- a/llvm/lib/Target/RISCV/RISCVISelLowering.cpp
+++ b/llvm/lib/Target/RISCV/RISCVISelLowering.cpp
@@ -4333,7 +4333,8 @@
 
   assert(VT.getVectorElementType() == MVT::i1);
 
-  if (!ShuffleVectorInst::isReverseMask(SVN->getMask()) ||
+  if (!ShuffleVectorInst::isReverseMask(SVN->getMask(),
+                                        SVN->getMask().size()) ||
       !SVN->getOperand(1).isUndef())
     return SDValue();
 
diff --git a/llvm/lib/Target/RISCV/RISCVTargetTransformInfo.cpp b/llvm/lib/Target/RISCV/RISCVTargetTransformInfo.cpp
--- a/llvm/lib/Target/RISCV/RISCVTargetTransformInfo.cpp
+++ b/llvm/lib/Target/RISCV/RISCVTargetTransformInfo.cpp
@@ -322,7 +322,10 @@
           LT.second.getVectorElementType().getSizeInBits() ==
               Tp->getElementType()->getPrimitiveSizeInBits() &&
           LT.second.getVectorNumElements() <
-              cast<FixedVectorType>(Tp)->getNumElements()) {
+              cast<FixedVectorType>(Tp)->getNumElements() &&
+          divideCeil(Mask.size(),
+                     cast<FixedVectorType>(Tp)->getNumElements()) ==
+              static_cast<unsigned>(*LT.first.getValue())) {
         unsigned NumRegs = *LT.first.getValue();
         unsigned VF = cast<FixedVectorType>(Tp)->getNumElements();
         unsigned SubVF = PowerOf2Ceil(VF / NumRegs);
@@ -498,7 +501,7 @@
     InstructionCost Cost = MemCost;
     for (unsigned Index : Indices) {
       FixedVectorType *SubVecTy =
-          FixedVectorType::get(FVTy->getElementType(), VF);
+          FixedVectorType::get(FVTy->getElementType(), VF * Factor);
       auto Mask = createStrideMask(Index, Factor, VF);
       InstructionCost ShuffleCost =
           getShuffleCost(TTI::ShuffleKind::SK_PermuteSingleSrc, SubVecTy, Mask,
diff --git a/llvm/lib/Target/X86/X86TargetTransformInfo.cpp b/llvm/lib/Target/X86/X86TargetTransformInfo.cpp
--- a/llvm/lib/Target/X86/X86TargetTransformInfo.cpp
+++ b/llvm/lib/Target/X86/X86TargetTransformInfo.cpp
@@ -1635,7 +1635,7 @@
             NormalizedMask, NumOfSrcRegs, NumOfDestRegs, NumOfDestRegs, []() {},
             [this, SingleOpTy, CostKind, &PrevSrcReg, &PrevRegMask,
              &Cost](ArrayRef<int> RegMask, unsigned SrcReg, unsigned DestReg) {
-              if (!ShuffleVectorInst::isIdentityMask(RegMask)) {
+              if (!ShuffleVectorInst::isIdentityMask(RegMask, RegMask.size())) {
                 // Check if the previous register can be just copied to the next
                 // one.
                 if (PrevRegMask.empty() || PrevSrcReg != SrcReg ||
diff --git a/llvm/lib/Transforms/InstCombine/InstCombineVectorOps.cpp b/llvm/lib/Transforms/InstCombine/InstCombineVectorOps.cpp
--- a/llvm/lib/Transforms/InstCombine/InstCombineVectorOps.cpp
+++ b/llvm/lib/Transforms/InstCombine/InstCombineVectorOps.cpp
@@ -2122,8 +2122,8 @@
     NewMask[i] = Mask[i] < (signed)NumElts ? Mask[i] : Mask1[i];
 
   // A select mask with undef elements might look like an identity mask.
-  assert((ShuffleVectorInst::isSelectMask(NewMask) ||
-          ShuffleVectorInst::isIdentityMask(NewMask)) &&
+  assert((ShuffleVectorInst::isSelectMask(NewMask, NumElts) ||
+          ShuffleVectorInst::isIdentityMask(NewMask, NumElts)) &&
          "Unexpected shuffle mask");
   return new ShuffleVectorInst(X, Y, NewMask);
 }
diff --git a/llvm/lib/Transforms/Vectorize/SLPVectorizer.cpp b/llvm/lib/Transforms/Vectorize/SLPVectorizer.cpp
--- a/llvm/lib/Transforms/Vectorize/SLPVectorizer.cpp
+++ b/llvm/lib/Transforms/Vectorize/SLPVectorizer.cpp
@@ -3812,7 +3812,7 @@
     inversePermutation(Order, MaskOrder);
   }
   reorderReuses(MaskOrder, Mask);
-  if (ShuffleVectorInst::isIdentityMask(MaskOrder)) {
+  if (ShuffleVectorInst::isIdentityMask(MaskOrder, MaskOrder.size())) {
     Order.clear();
     return;
   }
@@ -4333,7 +4333,7 @@
 static bool isRepeatedNonIdentityClusteredMask(ArrayRef<int> Mask,
                                                unsigned Sz) {
   ArrayRef<int> FirstCluster = Mask.slice(0, Sz);
-  if (ShuffleVectorInst::isIdentityMask(FirstCluster))
+  if (ShuffleVectorInst::isIdentityMask(FirstCluster, Sz))
     return false;
   for (unsigned I = Sz, E = Mask.size(); I < E; I += Sz) {
     ArrayRef<int> Cluster = Mask.slice(I, Sz);
@@ -6646,9 +6646,24 @@
                              bool IsStrict) {
     int Limit = Mask.size();
     int VF = VecTy->getNumElements();
-    return (VF == Limit || !IsStrict) &&
-           all_of(Mask, [Limit](int Idx) { return Idx < Limit; }) &&
-           ShuffleVectorInst::isIdentityMask(Mask);
+    int Index = -1;
+    if (VF == Limit && ShuffleVectorInst::isIdentityMask(Mask, Limit))
+      return true;
+    if (!IsStrict) {
+      // Consider extract subvector starting from index 0.
+      if (ShuffleVectorInst::isExtractSubvectorMask(Mask, VF, Index) &&
+          Index == 0)
+        return true;
+      // All VF-size submasks are identity (e.g.
+      // <poison,poison,poison,poison,0,1,2,poison,poison,1,2,3> etc. for VF 4).
+      if (Limit % VF == 0 && all_of(seq<int>(0, Limit / VF), [=](int Idx) {
+            ArrayRef<int> Slice = Mask.slice(Idx * VF, VF);
+            return all_of(Slice, [](int I) { return I == PoisonMaskElem; }) ||
+                   ShuffleVectorInst::isIdentityMask(Slice, VF);
+          }))
+        return true;
+    }
+    return false;
   }
 
   /// Tries to combine 2 different masks into single one.
@@ -6718,7 +6733,8 @@
       if (isIdentityMask(Mask, SVTy, /*IsStrict=*/false)) {
         if (!IdentityOp || !SinglePermute ||
             (isIdentityMask(Mask, SVTy, /*IsStrict=*/true) &&
-             !ShuffleVectorInst::isZeroEltSplatMask(IdentityMask))) {
+             !ShuffleVectorInst::isZeroEltSplatMask(IdentityMask,
+                                                    IdentityMask.size()))) {
           IdentityOp = SV;
           // Store current mask in the IdentityMask so later we did not lost
           // this info if IdentityOp is selected as the best candidate for the
@@ -6788,7 +6804,7 @@
     }
     if (auto *OpTy = dyn_cast<FixedVectorType>(Op->getType());
         !OpTy || !isIdentityMask(Mask, OpTy, SinglePermute) ||
-        ShuffleVectorInst::isZeroEltSplatMask(Mask)) {
+        ShuffleVectorInst::isZeroEltSplatMask(Mask, Mask.size())) {
       if (IdentityOp) {
         V = IdentityOp;
         assert(Mask.size() == IdentityMask.size() &&
@@ -6804,7 +6820,7 @@
                                /*IsStrict=*/true) ||
                 (Shuffle && Mask.size() == Shuffle->getShuffleMask().size() &&
                  Shuffle->isZeroEltSplat() &&
-                 ShuffleVectorInst::isZeroEltSplatMask(Mask)));
+                 ShuffleVectorInst::isZeroEltSplatMask(Mask, Mask.size())));
       }
       V = Op;
       return false;
@@ -6909,11 +6925,9 @@
           CombinedMask1[I] = CombinedMask2[I] + (Op1 == Op2 ? 0 : VF);
         }
       }
-      const int Limit = CombinedMask1.size() * 2;
-      if (Op1 == Op2 && Limit == 2 * VF &&
-          all_of(CombinedMask1, [=](int Idx) { return Idx < Limit; }) &&
-          (ShuffleVectorInst::isIdentityMask(CombinedMask1) ||
-           (ShuffleVectorInst::isZeroEltSplatMask(CombinedMask1) &&
+      if (Op1 == Op2 &&
+          (ShuffleVectorInst::isIdentityMask(CombinedMask1, VF) ||
+           (ShuffleVectorInst::isZeroEltSplatMask(CombinedMask1, VF) &&
             isa<ShuffleVectorInst>(Op1) &&
             cast<ShuffleVectorInst>(Op1)->getShuffleMask() ==
                 ArrayRef(CombinedMask1))))
@@ -7183,11 +7197,9 @@
     const TargetTransformInfo &TTI;
 
     static bool isEmptyOrIdentity(ArrayRef<int> Mask, unsigned VF) {
-      int Limit = 2 * VF;
       return Mask.empty() ||
              (VF == Mask.size() &&
-              all_of(Mask, [Limit](int Idx) { return Idx < Limit; }) &&
-              ShuffleVectorInst::isIdentityMask(Mask));
+              ShuffleVectorInst::isIdentityMask(Mask, VF));
     }
 
   public:
@@ -7445,9 +7457,7 @@
     ::addMask(CommonMask, ExtMask, /*ExtendingManyInputs=*/true);
     if (CommonMask.empty())
       return Cost;
-    int Limit = CommonMask.size() * 2;
-    if (all_of(CommonMask, [=](int Idx) { return Idx < Limit; }) &&
-        ShuffleVectorInst::isIdentityMask(CommonMask))
+    if (ShuffleVectorInst::isIdentityMask(CommonMask, CommonMask.size()))
       return Cost;
     return Cost +
            createShuffle(InVectors.front(),
@@ -7624,7 +7634,7 @@
   }
   if (NeedToShuffleReuses)
     ::addMask(Mask, E->ReuseShuffleIndices);
-  if (!Mask.empty() && !ShuffleVectorInst::isIdentityMask(Mask))
+  if (!Mask.empty() && !ShuffleVectorInst::isIdentityMask(Mask, Mask.size()))
     CommonCost =
         TTI->getShuffleCost(TTI::SK_PermuteSingleSrc, FinalVecTy, Mask);
   assert((E->State == TreeEntry::Vectorize ||
@@ -7975,7 +7985,7 @@
         } else {
           SmallVector<int> Mask;
           inversePermutation(OpTE->ReorderIndices, Mask);
-          if (ShuffleVectorInst::isReverseMask(Mask))
+          if (ShuffleVectorInst::isReverseMask(Mask, Mask.size()))
             CCH = TTI::CastContextHint::Reversed;
         }
       }
@@ -8834,9 +8844,7 @@
     unsigned VecVF = TE->getVectorFactor();
     if (VF != VecVF &&
         (any_of(Mask, [VF](int Idx) { return Idx >= static_cast<int>(VF); }) ||
-         (all_of(Mask,
-                 [VF](int Idx) { return Idx < 2 * static_cast<int>(VF); }) &&
-          !ShuffleVectorInst::isIdentityMask(Mask)))) {
+         !ShuffleVectorInst::isIdentityMask(Mask, VF))) {
       SmallVector<int> OrigMask(VecVF, PoisonMaskElem);
       std::copy(Mask.begin(), std::next(Mask.begin(), std::min(VF, VecVF)),
                 OrigMask.begin());
@@ -8865,9 +8873,7 @@
       assert((TEs.size() == 1 || TEs.size() == 2) &&
              "Expected exactly 1 or 2 tree entries.");
       if (TEs.size() == 1) {
-        int Limit = 2 * Mask.size();
-        if (!all_of(Mask, [Limit](int Idx) { return Idx < Limit; }) ||
-            !ShuffleVectorInst::isIdentityMask(Mask)) {
+        if (!ShuffleVectorInst::isIdentityMask(Mask, Mask.size())) {
           InstructionCost C =
               TTI->getShuffleCost(TTI::SK_PermuteSingleSrc, FTy, Mask);
           LLVM_DEBUG(dbgs() << "SLP: Adding cost " << C
@@ -9643,7 +9649,7 @@
         return V1;
       unsigned VF = Mask.size();
       unsigned LocalVF = cast<FixedVectorType>(V1->getType())->getNumElements();
-      if (VF == LocalVF && ShuffleVectorInst::isIdentityMask(Mask))
+      if (VF == LocalVF && ShuffleVectorInst::isIdentityMask(Mask, VF))
         return V1;
       Value *Vec = Builder.CreateShuffleVector(V1, Mask);
       if (auto *I = dyn_cast<Instruction>(Vec)) {
@@ -10056,9 +10062,7 @@
       return false;
     unsigned I =
         *find_if_not(Mask, [](int Idx) { return Idx == PoisonMaskElem; });
-    int Sz = Mask.size();
-    if (all_of(Mask, [Sz](int Idx) { return Idx < 2 * Sz; }) &&
-        ShuffleVectorInst::isIdentityMask(Mask))
+    if (ShuffleVectorInst::isIdentityMask(Mask, Mask.size()))
       std::iota(Mask.begin(), Mask.end(), 0);
     else
       std::fill(Mask.begin(), Mask.end(), I);
@@ -10302,11 +10306,11 @@
         (ExtractShuffle.value_or(TTI::SK_PermuteTwoSrc) ==
              TTI::SK_PermuteSingleSrc &&
          none_of(ExtractMask, [&](int I) { return I >= EMSz; }) &&
-         ShuffleVectorInst::isIdentityMask(ExtractMask)) ||
+         ShuffleVectorInst::isIdentityMask(ExtractMask, EMSz)) ||
         (GatherShuffle.value_or(TTI::SK_PermuteTwoSrc) ==
              TTI::SK_PermuteSingleSrc &&
          none_of(Mask, [&](int I) { return I >= MSz; }) &&
-         ShuffleVectorInst::isIdentityMask(Mask));
+         ShuffleVectorInst::isIdentityMask(Mask, MSz));
     bool EnoughConstsForShuffle =
         IsSingleShuffle &&
         (none_of(GatheredScalars,
@@ -10599,7 +10603,7 @@
       if ((!IsIdentity || Offset != 0 || !IsFirstUndef.all()) &&
           NumElts != NumScalars) {
         if (IsFirstUndef.all()) {
-          if (!ShuffleVectorInst::isIdentityMask(InsertMask)) {
+          if (!ShuffleVectorInst::isIdentityMask(InsertMask, NumElts)) {
             SmallBitVector IsFirstPoison =
                 isUndefVector<true>(FirstInsert->getOperand(0), UseMask);
             if (!IsFirstPoison.all()) {
@@ -11422,7 +11426,7 @@
             // non-resizing mask.
             if (Mask.size() != cast<FixedVectorType>(Vals.front()->getType())
                                    ->getNumElements() ||
-                !ShuffleVectorInst::isIdentityMask(Mask))
+                !ShuffleVectorInst::isIdentityMask(Mask, Mask.size()))
               return CreateShuffle(Vals.front(), nullptr, Mask);
             return Vals.front();
           }
diff --git a/llvm/test/Transforms/LoopVectorize/RISCV/interleaved-accesses.ll b/llvm/test/Transforms/LoopVectorize/RISCV/interleaved-accesses.ll
--- a/llvm/test/Transforms/LoopVectorize/RISCV/interleaved-accesses.ll
+++ b/llvm/test/Transforms/LoopVectorize/RISCV/interleaved-accesses.ll
@@ -461,44 +461,21 @@
 define void @combine_load_factor2_i64(ptr noalias %p, ptr noalias %q) {
 ; CHECK-LABEL: @combine_load_factor2_i64(
 ; CHECK-NEXT:  entry:
-; CHECK-NEXT:    br i1 false, label [[SCALAR_PH:%.*]], label [[VECTOR_PH:%.*]]
-; CHECK:       vector.ph:
-; CHECK-NEXT:    br label [[VECTOR_BODY:%.*]]
-; CHECK:       vector.body:
-; CHECK-NEXT:    [[INDEX:%.*]] = phi i64 [ 0, [[VECTOR_PH]] ], [ [[INDEX_NEXT:%.*]], [[VECTOR_BODY]] ]
-; CHECK-NEXT:    [[TMP0:%.*]] = add i64 [[INDEX]], 0
-; CHECK-NEXT:    [[TMP1:%.*]] = shl i64 [[TMP0]], 1
-; CHECK-NEXT:    [[TMP2:%.*]] = getelementptr i64, ptr [[P:%.*]], i64 [[TMP1]]
-; CHECK-NEXT:    [[TMP3:%.*]] = getelementptr i64, ptr [[TMP2]], i32 0
-; CHECK-NEXT:    [[WIDE_VEC:%.*]] = load <8 x i64>, ptr [[TMP3]], align 4
-; CHECK-NEXT:    [[STRIDED_VEC:%.*]] = shufflevector <8 x i64> [[WIDE_VEC]], <8 x i64> poison, <4 x i32> <i32 0, i32 2, i32 4, i32 6>
-; CHECK-NEXT:    [[STRIDED_VEC1:%.*]] = shufflevector <8 x i64> [[WIDE_VEC]], <8 x i64> poison, <4 x i32> <i32 1, i32 3, i32 5, i32 7>
-; CHECK-NEXT:    [[TMP4:%.*]] = add <4 x i64> [[STRIDED_VEC]], [[STRIDED_VEC1]]
-; CHECK-NEXT:    [[TMP5:%.*]] = getelementptr i64, ptr [[Q:%.*]], i64 [[TMP0]]
-; CHECK-NEXT:    [[TMP6:%.*]] = getelementptr i64, ptr [[TMP5]], i32 0
-; CHECK-NEXT:    store <4 x i64> [[TMP4]], ptr [[TMP6]], align 4
-; CHECK-NEXT:    [[INDEX_NEXT]] = add nuw i64 [[INDEX]], 4
-; CHECK-NEXT:    [[TMP7:%.*]] = icmp eq i64 [[INDEX_NEXT]], 1024
-; CHECK-NEXT:    br i1 [[TMP7]], label [[MIDDLE_BLOCK:%.*]], label [[VECTOR_BODY]], !llvm.loop [[LOOP8:![0-9]+]]
-; CHECK:       middle.block:
-; CHECK-NEXT:    br i1 true, label [[EXIT:%.*]], label [[SCALAR_PH]]
-; CHECK:       scalar.ph:
-; CHECK-NEXT:    [[BC_RESUME_VAL:%.*]] = phi i64 [ 1024, [[MIDDLE_BLOCK]] ], [ 0, [[ENTRY:%.*]] ]
 ; CHECK-NEXT:    br label [[LOOP:%.*]]
 ; CHECK:       loop:
-; CHECK-NEXT:    [[I:%.*]] = phi i64 [ [[BC_RESUME_VAL]], [[SCALAR_PH]] ], [ [[NEXTI:%.*]], [[LOOP]] ]
+; CHECK-NEXT:    [[I:%.*]] = phi i64 [ 0, [[ENTRY:%.*]] ], [ [[NEXTI:%.*]], [[LOOP]] ]
 ; CHECK-NEXT:    [[OFFSET0:%.*]] = shl i64 [[I]], 1
-; CHECK-NEXT:    [[Q0:%.*]] = getelementptr i64, ptr [[P]], i64 [[OFFSET0]]
+; CHECK-NEXT:    [[Q0:%.*]] = getelementptr i64, ptr [[P:%.*]], i64 [[OFFSET0]]
 ; CHECK-NEXT:    [[X0:%.*]] = load i64, ptr [[Q0]], align 4
 ; CHECK-NEXT:    [[OFFSET1:%.*]] = add i64 [[OFFSET0]], 1
 ; CHECK-NEXT:    [[Q1:%.*]] = getelementptr i64, ptr [[P]], i64 [[OFFSET1]]
 ; CHECK-NEXT:    [[X1:%.*]] = load i64, ptr [[Q1]], align 4
 ; CHECK-NEXT:    [[RES:%.*]] = add i64 [[X0]], [[X1]]
-; CHECK-NEXT:    [[DST:%.*]] = getelementptr i64, ptr [[Q]], i64 [[I]]
+; CHECK-NEXT:    [[DST:%.*]] = getelementptr i64, ptr [[Q:%.*]], i64 [[I]]
 ; CHECK-NEXT:    store i64 [[RES]], ptr [[DST]], align 4
 ; CHECK-NEXT:    [[NEXTI]] = add i64 [[I]], 1
 ; CHECK-NEXT:    [[DONE:%.*]] = icmp eq i64 [[NEXTI]], 1024
-; CHECK-NEXT:    br i1 [[DONE]], label [[EXIT]], label [[LOOP]], !llvm.loop [[LOOP9:![0-9]+]]
+; CHECK-NEXT:    br i1 [[DONE]], label [[EXIT:%.*]], label [[LOOP]]
 ; CHECK:       exit:
 ; CHECK-NEXT:    ret void
 ;
diff --git a/llvm/unittests/IR/InstructionsTest.cpp b/llvm/unittests/IR/InstructionsTest.cpp
--- a/llvm/unittests/IR/InstructionsTest.cpp
+++ b/llvm/unittests/IR/InstructionsTest.cpp
@@ -1024,71 +1024,141 @@
   Constant *C7 = ConstantInt::get(Int32Ty, 7);
 
   Constant *Identity = ConstantVector::get({C0, CU, C2, C3, C4});
-  EXPECT_TRUE(ShuffleVectorInst::isIdentityMask(Identity));
-  EXPECT_FALSE(ShuffleVectorInst::isSelectMask(Identity)); // identity is distinguished from select
-  EXPECT_FALSE(ShuffleVectorInst::isReverseMask(Identity));
-  EXPECT_TRUE(ShuffleVectorInst::isSingleSourceMask(Identity)); // identity is always single source
-  EXPECT_FALSE(ShuffleVectorInst::isZeroEltSplatMask(Identity));
-  EXPECT_FALSE(ShuffleVectorInst::isTransposeMask(Identity));
+  EXPECT_TRUE(ShuffleVectorInst::isIdentityMask(
+      Identity, cast<FixedVectorType>(Identity->getType())->getNumElements()));
+  EXPECT_FALSE(ShuffleVectorInst::isSelectMask(
+      Identity,
+      cast<FixedVectorType>(Identity->getType())
+          ->getNumElements())); // identity is distinguished from select
+  EXPECT_FALSE(ShuffleVectorInst::isReverseMask(
+      Identity, cast<FixedVectorType>(Identity->getType())->getNumElements()));
+  EXPECT_TRUE(ShuffleVectorInst::isSingleSourceMask(
+      Identity, cast<FixedVectorType>(Identity->getType())
+                    ->getNumElements())); // identity is always single source
+  EXPECT_FALSE(ShuffleVectorInst::isZeroEltSplatMask(
+      Identity, cast<FixedVectorType>(Identity->getType())->getNumElements()));
+  EXPECT_FALSE(ShuffleVectorInst::isTransposeMask(
+      Identity, cast<FixedVectorType>(Identity->getType())->getNumElements()));
 
   Constant *Select = ConstantVector::get({CU, C1, C5});
-  EXPECT_FALSE(ShuffleVectorInst::isIdentityMask(Select));
-  EXPECT_TRUE(ShuffleVectorInst::isSelectMask(Select));
-  EXPECT_FALSE(ShuffleVectorInst::isReverseMask(Select));
-  EXPECT_FALSE(ShuffleVectorInst::isSingleSourceMask(Select));
-  EXPECT_FALSE(ShuffleVectorInst::isZeroEltSplatMask(Select));
-  EXPECT_FALSE(ShuffleVectorInst::isTransposeMask(Select));
-  
+  EXPECT_FALSE(ShuffleVectorInst::isIdentityMask(
+      Select, cast<FixedVectorType>(Select->getType())->getNumElements()));
+  EXPECT_TRUE(ShuffleVectorInst::isSelectMask(
+      Select, cast<FixedVectorType>(Select->getType())->getNumElements()));
+  EXPECT_FALSE(ShuffleVectorInst::isReverseMask(
+      Select, cast<FixedVectorType>(Select->getType())->getNumElements()));
+  EXPECT_FALSE(ShuffleVectorInst::isSingleSourceMask(
+      Select, cast<FixedVectorType>(Select->getType())->getNumElements()));
+  EXPECT_FALSE(ShuffleVectorInst::isZeroEltSplatMask(
+      Select, cast<FixedVectorType>(Select->getType())->getNumElements()));
+  EXPECT_FALSE(ShuffleVectorInst::isTransposeMask(
+      Select, cast<FixedVectorType>(Select->getType())->getNumElements()));
+
   Constant *Reverse = ConstantVector::get({C3, C2, C1, CU});
-  EXPECT_FALSE(ShuffleVectorInst::isIdentityMask(Reverse));
-  EXPECT_FALSE(ShuffleVectorInst::isSelectMask(Reverse));
-  EXPECT_TRUE(ShuffleVectorInst::isReverseMask(Reverse));
-  EXPECT_TRUE(ShuffleVectorInst::isSingleSourceMask(Reverse)); // reverse is always single source
-  EXPECT_FALSE(ShuffleVectorInst::isZeroEltSplatMask(Reverse));
-  EXPECT_FALSE(ShuffleVectorInst::isTransposeMask(Reverse));
+  EXPECT_FALSE(ShuffleVectorInst::isIdentityMask(
+      Reverse, cast<FixedVectorType>(Reverse->getType())->getNumElements()));
+  EXPECT_FALSE(ShuffleVectorInst::isSelectMask(
+      Reverse, cast<FixedVectorType>(Reverse->getType())->getNumElements()));
+  EXPECT_TRUE(ShuffleVectorInst::isReverseMask(
+      Reverse, cast<FixedVectorType>(Reverse->getType())->getNumElements()));
+  EXPECT_TRUE(ShuffleVectorInst::isSingleSourceMask(
+      Reverse, cast<FixedVectorType>(Reverse->getType())
+                   ->getNumElements())); // reverse is always single source
+  EXPECT_FALSE(ShuffleVectorInst::isZeroEltSplatMask(
+      Reverse, cast<FixedVectorType>(Reverse->getType())->getNumElements()));
+  EXPECT_FALSE(ShuffleVectorInst::isTransposeMask(
+      Reverse, cast<FixedVectorType>(Reverse->getType())->getNumElements()));
 
   Constant *SingleSource = ConstantVector::get({C2, C2, C0, CU});
-  EXPECT_FALSE(ShuffleVectorInst::isIdentityMask(SingleSource));
-  EXPECT_FALSE(ShuffleVectorInst::isSelectMask(SingleSource));
-  EXPECT_FALSE(ShuffleVectorInst::isReverseMask(SingleSource));
-  EXPECT_TRUE(ShuffleVectorInst::isSingleSourceMask(SingleSource));
-  EXPECT_FALSE(ShuffleVectorInst::isZeroEltSplatMask(SingleSource));
-  EXPECT_FALSE(ShuffleVectorInst::isTransposeMask(SingleSource));
+  EXPECT_FALSE(ShuffleVectorInst::isIdentityMask(
+      SingleSource,
+      cast<FixedVectorType>(SingleSource->getType())->getNumElements()));
+  EXPECT_FALSE(ShuffleVectorInst::isSelectMask(
+      SingleSource,
+      cast<FixedVectorType>(SingleSource->getType())->getNumElements()));
+  EXPECT_FALSE(ShuffleVectorInst::isReverseMask(
+      SingleSource,
+      cast<FixedVectorType>(SingleSource->getType())->getNumElements()));
+  EXPECT_TRUE(ShuffleVectorInst::isSingleSourceMask(
+      SingleSource,
+      cast<FixedVectorType>(SingleSource->getType())->getNumElements()));
+  EXPECT_FALSE(ShuffleVectorInst::isZeroEltSplatMask(
+      SingleSource,
+      cast<FixedVectorType>(SingleSource->getType())->getNumElements()));
+  EXPECT_FALSE(ShuffleVectorInst::isTransposeMask(
+      SingleSource,
+      cast<FixedVectorType>(SingleSource->getType())->getNumElements()));
 
   Constant *ZeroEltSplat = ConstantVector::get({C0, C0, CU, C0});
-  EXPECT_FALSE(ShuffleVectorInst::isIdentityMask(ZeroEltSplat));
-  EXPECT_FALSE(ShuffleVectorInst::isSelectMask(ZeroEltSplat));
-  EXPECT_FALSE(ShuffleVectorInst::isReverseMask(ZeroEltSplat));
-  EXPECT_TRUE(ShuffleVectorInst::isSingleSourceMask(ZeroEltSplat)); // 0-splat is always single source
-  EXPECT_TRUE(ShuffleVectorInst::isZeroEltSplatMask(ZeroEltSplat));
-  EXPECT_FALSE(ShuffleVectorInst::isTransposeMask(ZeroEltSplat));
+  EXPECT_FALSE(ShuffleVectorInst::isIdentityMask(
+      ZeroEltSplat,
+      cast<FixedVectorType>(ZeroEltSplat->getType())->getNumElements()));
+  EXPECT_FALSE(ShuffleVectorInst::isSelectMask(
+      ZeroEltSplat,
+      cast<FixedVectorType>(ZeroEltSplat->getType())->getNumElements()));
+  EXPECT_FALSE(ShuffleVectorInst::isReverseMask(
+      ZeroEltSplat,
+      cast<FixedVectorType>(ZeroEltSplat->getType())->getNumElements()));
+  EXPECT_TRUE(ShuffleVectorInst::isSingleSourceMask(
+      ZeroEltSplat, cast<FixedVectorType>(ZeroEltSplat->getType())
+                        ->getNumElements())); // 0-splat is always single source
+  EXPECT_TRUE(ShuffleVectorInst::isZeroEltSplatMask(
+      ZeroEltSplat,
+      cast<FixedVectorType>(ZeroEltSplat->getType())->getNumElements()));
+  EXPECT_FALSE(ShuffleVectorInst::isTransposeMask(
+      ZeroEltSplat,
+      cast<FixedVectorType>(ZeroEltSplat->getType())->getNumElements()));
 
   Constant *Transpose = ConstantVector::get({C0, C4, C2, C6});
-  EXPECT_FALSE(ShuffleVectorInst::isIdentityMask(Transpose));
-  EXPECT_FALSE(ShuffleVectorInst::isSelectMask(Transpose));
-  EXPECT_FALSE(ShuffleVectorInst::isReverseMask(Transpose));
-  EXPECT_FALSE(ShuffleVectorInst::isSingleSourceMask(Transpose));
-  EXPECT_FALSE(ShuffleVectorInst::isZeroEltSplatMask(Transpose));
-  EXPECT_TRUE(ShuffleVectorInst::isTransposeMask(Transpose));
+  EXPECT_FALSE(ShuffleVectorInst::isIdentityMask(
+      Transpose,
+      cast<FixedVectorType>(Transpose->getType())->getNumElements()));
+  EXPECT_FALSE(ShuffleVectorInst::isSelectMask(
+      Transpose,
+      cast<FixedVectorType>(Transpose->getType())->getNumElements()));
+  EXPECT_FALSE(ShuffleVectorInst::isReverseMask(
+      Transpose,
+      cast<FixedVectorType>(Transpose->getType())->getNumElements()));
+  EXPECT_FALSE(ShuffleVectorInst::isSingleSourceMask(
+      Transpose,
+      cast<FixedVectorType>(Transpose->getType())->getNumElements()));
+  EXPECT_FALSE(ShuffleVectorInst::isZeroEltSplatMask(
+      Transpose,
+      cast<FixedVectorType>(Transpose->getType())->getNumElements()));
+  EXPECT_TRUE(ShuffleVectorInst::isTransposeMask(
+      Transpose,
+      cast<FixedVectorType>(Transpose->getType())->getNumElements()));
 
   // More tests to make sure the logic is/stays correct...
-  EXPECT_TRUE(ShuffleVectorInst::isIdentityMask(ConstantVector::get({CU, C1, CU, C3})));
-  EXPECT_TRUE(ShuffleVectorInst::isIdentityMask(ConstantVector::get({C4, CU, C6, CU})));
-
-  EXPECT_TRUE(ShuffleVectorInst::isSelectMask(ConstantVector::get({C4, C1, C6, CU})));
-  EXPECT_TRUE(ShuffleVectorInst::isSelectMask(ConstantVector::get({CU, C1, C6, C3})));
-
-  EXPECT_TRUE(ShuffleVectorInst::isReverseMask(ConstantVector::get({C7, C6, CU, C4})));
-  EXPECT_TRUE(ShuffleVectorInst::isReverseMask(ConstantVector::get({C3, CU, C1, CU})));
-
-  EXPECT_TRUE(ShuffleVectorInst::isSingleSourceMask(ConstantVector::get({C7, C5, CU, C7})));
-  EXPECT_TRUE(ShuffleVectorInst::isSingleSourceMask(ConstantVector::get({C3, C0, CU, C3})));
-
-  EXPECT_TRUE(ShuffleVectorInst::isZeroEltSplatMask(ConstantVector::get({C4, CU, CU, C4})));
-  EXPECT_TRUE(ShuffleVectorInst::isZeroEltSplatMask(ConstantVector::get({CU, C0, CU, C0})));
-
-  EXPECT_TRUE(ShuffleVectorInst::isTransposeMask(ConstantVector::get({C1, C5, C3, C7})));
-  EXPECT_TRUE(ShuffleVectorInst::isTransposeMask(ConstantVector::get({C1, C3})));
+  EXPECT_TRUE(ShuffleVectorInst::isIdentityMask(
+      ConstantVector::get({CU, C1, CU, C3}), 4));
+  EXPECT_TRUE(ShuffleVectorInst::isIdentityMask(
+      ConstantVector::get({C4, CU, C6, CU}), 4));
+
+  EXPECT_TRUE(ShuffleVectorInst::isSelectMask(
+      ConstantVector::get({C4, C1, C6, CU}), 4));
+  EXPECT_TRUE(ShuffleVectorInst::isSelectMask(
+      ConstantVector::get({CU, C1, C6, C3}), 4));
+
+  EXPECT_TRUE(ShuffleVectorInst::isReverseMask(
+      ConstantVector::get({C7, C6, CU, C4}), 4));
+  EXPECT_TRUE(ShuffleVectorInst::isReverseMask(
+      ConstantVector::get({C3, CU, C1, CU}), 4));
+
+  EXPECT_TRUE(ShuffleVectorInst::isSingleSourceMask(
+      ConstantVector::get({C7, C5, CU, C7}), 4));
+  EXPECT_TRUE(ShuffleVectorInst::isSingleSourceMask(
+      ConstantVector::get({C3, C0, CU, C3}), 4));
+
+  EXPECT_TRUE(ShuffleVectorInst::isZeroEltSplatMask(
+      ConstantVector::get({C4, CU, CU, C4}), 4));
+  EXPECT_TRUE(ShuffleVectorInst::isZeroEltSplatMask(
+      ConstantVector::get({CU, C0, CU, C0}), 4));
+
+  EXPECT_TRUE(ShuffleVectorInst::isTransposeMask(
+      ConstantVector::get({C1, C5, C3, C7}), 4));
+  EXPECT_TRUE(
+      ShuffleVectorInst::isTransposeMask(ConstantVector::get({C1, C3}), 2));
 
   // Nothing special about the values here - just re-using inputs to reduce code. 
   Constant *V0 = ConstantVector::get({C0, C1, C2, C3});
diff --git a/llvm/unittests/IR/ShuffleVectorInstTest.cpp b/llvm/unittests/IR/ShuffleVectorInstTest.cpp
--- a/llvm/unittests/IR/ShuffleVectorInstTest.cpp
+++ b/llvm/unittests/IR/ShuffleVectorInstTest.cpp
@@ -14,51 +14,84 @@
 namespace {
 
 TEST(ShuffleVectorInst, isIdentityMask) {
-  ASSERT_TRUE(ShuffleVectorInst::isIdentityMask({0, 1, 2, 3}));
-  ASSERT_TRUE(ShuffleVectorInst::isIdentityMask({0, 1, 2, 3, -1}));
-  ASSERT_TRUE(ShuffleVectorInst::isIdentityMask({0, 1, -1, 3}));
+  ASSERT_TRUE(ShuffleVectorInst::isIdentityMask({0, 1, 2, 3}, 4));
+  ASSERT_TRUE(ShuffleVectorInst::isIdentityMask({0, 1, 2, 3, -1}, 5));
+  ASSERT_TRUE(ShuffleVectorInst::isIdentityMask({0, 1, -1, 3}, 4));
 
-  ASSERT_FALSE(ShuffleVectorInst::isIdentityMask({0, 1, 2, 4}));
-  ASSERT_FALSE(ShuffleVectorInst::isIdentityMask({0, -1, 2, 4}));
+  ASSERT_FALSE(ShuffleVectorInst::isIdentityMask({0, 1, 2, 3}, 3));
+  ASSERT_FALSE(ShuffleVectorInst::isIdentityMask({0, 1, 2, 3, -1}, 4));
+  ASSERT_FALSE(ShuffleVectorInst::isIdentityMask({0, 1, -1, 3}, 3));
+
+  ASSERT_FALSE(ShuffleVectorInst::isIdentityMask({0, 1, 2, 3}, 5));
+  ASSERT_FALSE(ShuffleVectorInst::isIdentityMask({0, 1, 2, 3, -1}, 6));
+  ASSERT_FALSE(ShuffleVectorInst::isIdentityMask({0, 1, -1, 3}, 5));
+
+  ASSERT_FALSE(ShuffleVectorInst::isIdentityMask({0, 1, 2, 4}, 4));
+  ASSERT_FALSE(ShuffleVectorInst::isIdentityMask({0, -1, 2, 4}, 4));
 }
 
 TEST(ShuffleVectorInst, isSelectMask) {
-  ASSERT_TRUE(ShuffleVectorInst::isSelectMask({0, 5, 6, 3}));
+  ASSERT_TRUE(ShuffleVectorInst::isSelectMask({0, 5, 6, 3}, 4));
+
+  ASSERT_FALSE(ShuffleVectorInst::isSelectMask({0, 5, 6, 3}, 3));
+  ASSERT_FALSE(ShuffleVectorInst::isSelectMask({0, 5, 6, 3}, 5));
 
-  ASSERT_FALSE(ShuffleVectorInst::isSelectMask({0, 1, 2, 3}));
+  ASSERT_FALSE(ShuffleVectorInst::isSelectMask({0, 1, 2, 3}, 4));
 }
 
 TEST(ShuffleVectorInst, isReverseMask) {
-  ASSERT_TRUE(ShuffleVectorInst::isReverseMask({3, 2, 1, 0}));
-  ASSERT_TRUE(ShuffleVectorInst::isReverseMask({-1, -1, 1, 0}));
+  ASSERT_TRUE(ShuffleVectorInst::isReverseMask({3, 2, 1, 0}, 4));
+  ASSERT_TRUE(ShuffleVectorInst::isReverseMask({-1, -1, 1, 0}, 4));
 
-  ASSERT_FALSE(ShuffleVectorInst::isReverseMask({4, 3, 2, 1}));
+  ASSERT_FALSE(ShuffleVectorInst::isReverseMask({3, 2, 1, 0}, 3));
+  ASSERT_FALSE(ShuffleVectorInst::isReverseMask({-1, -1, 1, 0}, 3));
+  ASSERT_FALSE(ShuffleVectorInst::isReverseMask({3, 2, 1, 0}, 5));
+  ASSERT_FALSE(ShuffleVectorInst::isReverseMask({-1, -1, 1, 0}, 5));
+
+  ASSERT_FALSE(ShuffleVectorInst::isReverseMask({4, 3, 2, 1}, 4));
 }
 
 TEST(ShuffleVectorInst, isZeroEltSplatMask) {
-  ASSERT_TRUE(ShuffleVectorInst::isZeroEltSplatMask({0, 0, 0, 0}));
-  ASSERT_TRUE(ShuffleVectorInst::isZeroEltSplatMask({0, -1, 0, -1}));
+  ASSERT_TRUE(ShuffleVectorInst::isZeroEltSplatMask({0, 0, 0, 0}, 4));
+  ASSERT_TRUE(ShuffleVectorInst::isZeroEltSplatMask({0, -1, 0, -1}, 4));
+
+  ASSERT_FALSE(ShuffleVectorInst::isZeroEltSplatMask({0, 0, 0, 0}, 3));
+  ASSERT_FALSE(ShuffleVectorInst::isZeroEltSplatMask({0, -1, 0, -1}, 3));
+  ASSERT_FALSE(ShuffleVectorInst::isZeroEltSplatMask({0, 0, 0, 0}, 5));
+  ASSERT_FALSE(ShuffleVectorInst::isZeroEltSplatMask({0, -1, 0, -1}, 5));
 
-  ASSERT_FALSE(ShuffleVectorInst::isZeroEltSplatMask({1, 1, 1, 1}));
+  ASSERT_FALSE(ShuffleVectorInst::isZeroEltSplatMask({1, 1, 1, 1}, 4));
 }
 
 TEST(ShuffleVectorInst, isTransposeMask) {
-  ASSERT_TRUE(ShuffleVectorInst::isTransposeMask({0, 4, 2, 6}));
-  ASSERT_TRUE(ShuffleVectorInst::isTransposeMask({1, 5, 3, 7}));
+  ASSERT_TRUE(ShuffleVectorInst::isTransposeMask({0, 4, 2, 6}, 4));
+  ASSERT_TRUE(ShuffleVectorInst::isTransposeMask({1, 5, 3, 7}, 4));
 
-  ASSERT_FALSE(ShuffleVectorInst::isTransposeMask({2, 6, 4, 8}));
+  ASSERT_FALSE(ShuffleVectorInst::isTransposeMask({0, 4, 2, 6}, 3));
+  ASSERT_FALSE(ShuffleVectorInst::isTransposeMask({1, 5, 3, 7}, 3));
+  ASSERT_FALSE(ShuffleVectorInst::isTransposeMask({0, 4, 2, 6}, 5));
+  ASSERT_FALSE(ShuffleVectorInst::isTransposeMask({1, 5, 3, 7}, 5));
+
+  ASSERT_FALSE(ShuffleVectorInst::isTransposeMask({2, 6, 4, 8}, 4));
 }
 
 TEST(ShuffleVectorInst, isSpliceMask) {
   int Index;
 
-  ASSERT_TRUE(ShuffleVectorInst::isSpliceMask({0, 1, 2, 3}, Index));
+  ASSERT_TRUE(ShuffleVectorInst::isSpliceMask({0, 1, 2, 3}, 4, Index));
   ASSERT_EQ(0, Index);
 
-  ASSERT_TRUE(ShuffleVectorInst::isSpliceMask({1, 2, 3, 4, 5, 6, 7}, Index));
+  ASSERT_TRUE(ShuffleVectorInst::isSpliceMask({1, 2, 3, 4, 5, 6, 7}, 7, Index));
   ASSERT_EQ(1, Index);
 
-  ASSERT_FALSE(ShuffleVectorInst::isSpliceMask({4, 5, 6, 7}, Index));
+  ASSERT_FALSE(ShuffleVectorInst::isSpliceMask({0, 1, 2, 3}, 3, Index));
+  ASSERT_FALSE(
+      ShuffleVectorInst::isSpliceMask({1, 2, 3, 4, 5, 6, 7}, 6, Index));
+  ASSERT_FALSE(ShuffleVectorInst::isSpliceMask({0, 1, 2, 3}, 5, Index));
+  ASSERT_FALSE(
+      ShuffleVectorInst::isSpliceMask({1, 2, 3, 4, 5, 6, 7}, 8, Index));
+
+  ASSERT_FALSE(ShuffleVectorInst::isSpliceMask({4, 5, 6, 7}, 4, Index));
 }
 
 TEST(ShuffleVectorInst, isExtractSubvectorMask) {