diff --git a/llvm/include/llvm/Analysis/TargetTransformInfo.h b/llvm/include/llvm/Analysis/TargetTransformInfo.h
--- a/llvm/include/llvm/Analysis/TargetTransformInfo.h
+++ b/llvm/include/llvm/Analysis/TargetTransformInfo.h
@@ -660,7 +660,7 @@
 
   /// \Returns true if the target supports broadcasting a load to a vector of
   /// type <NumElements x ElementTy>.
-  bool isLegalBroadcastLoad(Type *ElementTy, unsigned NumElements) const;
+  bool isLegalBroadcastLoad(Type *ElementTy, ElementCount NumElements) const;
 
   /// Return true if the target supports masked scatter.
   bool isLegalMaskedScatter(Type *DataType, Align Alignment) const;
@@ -1561,7 +1561,7 @@
   virtual bool isLegalNTStore(Type *DataType, Align Alignment) = 0;
   virtual bool isLegalNTLoad(Type *DataType, Align Alignment) = 0;
   virtual bool isLegalBroadcastLoad(Type *ElementTy,
-                                    unsigned NumElements) const = 0;
+                                    ElementCount NumElements) const = 0;
   virtual bool isLegalMaskedScatter(Type *DataType, Align Alignment) = 0;
   virtual bool isLegalMaskedGather(Type *DataType, Align Alignment) = 0;
   virtual bool forceScalarizeMaskedGather(VectorType *DataType,
@@ -1970,7 +1970,7 @@
     return Impl.isLegalNTLoad(DataType, Alignment);
   }
   bool isLegalBroadcastLoad(Type *ElementTy,
-                            unsigned NumElements) const override {
+                            ElementCount NumElements) const override {
     return Impl.isLegalBroadcastLoad(ElementTy, NumElements);
   }
   bool isLegalMaskedScatter(Type *DataType, Align Alignment) override {
diff --git a/llvm/include/llvm/Analysis/TargetTransformInfoImpl.h b/llvm/include/llvm/Analysis/TargetTransformInfoImpl.h
--- a/llvm/include/llvm/Analysis/TargetTransformInfoImpl.h
+++ b/llvm/include/llvm/Analysis/TargetTransformInfoImpl.h
@@ -256,7 +256,7 @@
     return Alignment >= DataSize && isPowerOf2_32(DataSize);
   }
 
-  bool isLegalBroadcastLoad(Type *ElementTy, unsigned NumElements) const {
+  bool isLegalBroadcastLoad(Type *ElementTy, ElementCount NumElements) const {
     return false;
   }
 
diff --git a/llvm/lib/Analysis/TargetTransformInfo.cpp b/llvm/lib/Analysis/TargetTransformInfo.cpp
--- a/llvm/lib/Analysis/TargetTransformInfo.cpp
+++ b/llvm/lib/Analysis/TargetTransformInfo.cpp
@@ -397,7 +397,7 @@
 }
 
 bool TargetTransformInfo::isLegalBroadcastLoad(Type *ElementTy,
-                                               unsigned NumElements) const {
+                                               ElementCount NumElements) const {
   return TTIImpl->isLegalBroadcastLoad(ElementTy, NumElements);
 }
 
diff --git a/llvm/lib/Target/X86/X86TargetTransformInfo.h b/llvm/lib/Target/X86/X86TargetTransformInfo.h
--- a/llvm/lib/Target/X86/X86TargetTransformInfo.h
+++ b/llvm/lib/Target/X86/X86TargetTransformInfo.h
@@ -227,7 +227,7 @@
   bool isLegalMaskedStore(Type *DataType, Align Alignment);
   bool isLegalNTLoad(Type *DataType, Align Alignment);
   bool isLegalNTStore(Type *DataType, Align Alignment);
-  bool isLegalBroadcastLoad(Type *ElementTy, unsigned NumElements) const;
+  bool isLegalBroadcastLoad(Type *ElementTy, ElementCount NumElements) const;
   bool forceScalarizeMaskedGather(VectorType *VTy, Align Alignment);
   bool forceScalarizeMaskedScatter(VectorType *VTy, Align Alignment) {
     return forceScalarizeMaskedGather(VTy, Alignment);
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
@@ -1558,7 +1558,7 @@
       if (const auto *Entry =
               CostTableLookup(SSE3BroadcastLoadTbl, Kind, LT.second)) {
         assert(isLegalBroadcastLoad(BaseTp->getElementType(),
-                                    LT.second.getVectorNumElements()) &&
+                                    LT.second.getVectorElementCount()) &&
                "Table entry missing from isLegalBroadcastLoad()");
         return LT.first * Entry->Cost;
       }
@@ -5137,9 +5137,10 @@
 }
 
 bool X86TTIImpl::isLegalBroadcastLoad(Type *ElementTy,
-                                      unsigned NumElements) const {
+                                      ElementCount NumElements) const {
   // movddup
-  return ST->hasSSE3() && NumElements == 2 &&
+  return ST->hasSSE3() && !NumElements.isScalable() &&
+         NumElements.getFixedValue() == 2 &&
          ElementTy == Type::getDoubleTy(ElementTy->getContext());
 }
 
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
@@ -1176,7 +1176,8 @@
         if (isa<LoadInst>(V1)) {
           // A broadcast of a load can be cheaper on some targets.
           // TODO: For now accept a broadcast load with no other internal uses.
-          if (TTI->isLegalBroadcastLoad(V1->getType(), NumLanes) &&
+          if (TTI->isLegalBroadcastLoad(V1->getType(),
+                                        ElementCount::getFixed(NumLanes)) &&
               (int)V1->getNumUses() == NumLanes)
             return VLOperands::ScoreSplatLoads;
         }