Index: include/llvm/Analysis/TargetTransformInfo.h
===================================================================
--- include/llvm/Analysis/TargetTransformInfo.h
+++ include/llvm/Analysis/TargetTransformInfo.h
@@ -437,6 +437,10 @@
   /// \return The width of the largest scalar or vector register type.
   unsigned getRegisterBitWidth(bool Vector) const;
 
+  /// \return The bitwidth of the largest vector type that should be used to
+  /// load/store in the given address space.
+  unsigned getLoadStoreVecRegBitWidth(unsigned AddrSpace) const;
+
   /// \return The size of a cache line in bytes.
   unsigned getCacheLineSize() const;
 
@@ -649,6 +653,7 @@
                             Type *Ty) = 0;
   virtual unsigned getNumberOfRegisters(bool Vector) = 0;
   virtual unsigned getRegisterBitWidth(bool Vector) = 0;
+  virtual unsigned getLoadStoreVecRegBitWidth(unsigned AddrSpace) = 0;
   virtual unsigned getCacheLineSize() = 0;
   virtual unsigned getPrefetchDistance() = 0;
   virtual unsigned getMinPrefetchStride() = 0;
@@ -827,6 +832,11 @@
   unsigned getRegisterBitWidth(bool Vector) override {
     return Impl.getRegisterBitWidth(Vector);
   }
+
+  unsigned getLoadStoreVecRegBitWidth(unsigned AddrSpace) override {
+    return Impl.getLoadStoreVecRegBitWidth(AddrSpace);
+  }
+
   unsigned getCacheLineSize() override {
     return Impl.getCacheLineSize();
   }
Index: include/llvm/Analysis/TargetTransformInfoImpl.h
===================================================================
--- include/llvm/Analysis/TargetTransformInfoImpl.h
+++ include/llvm/Analysis/TargetTransformInfoImpl.h
@@ -268,6 +268,8 @@
 
   unsigned getRegisterBitWidth(bool Vector) { return 32; }
 
+  unsigned getLoadStoreVecRegBitWidth(unsigned AddrSpace) { return 128; }
+
   unsigned getCacheLineSize() { return 0; }
 
   unsigned getPrefetchDistance() { return 0; }
Index: lib/Analysis/TargetTransformInfo.cpp
===================================================================
--- lib/Analysis/TargetTransformInfo.cpp
+++ lib/Analysis/TargetTransformInfo.cpp
@@ -223,6 +223,10 @@
   return TTIImpl->getRegisterBitWidth(Vector);
 }
 
+unsigned TargetTransformInfo::getLoadStoreVecRegBitWidth(unsigned AS) const {
+  return TTIImpl->getLoadStoreVecRegBitWidth(AS);
+}
+
 unsigned TargetTransformInfo::getCacheLineSize() const {
   return TTIImpl->getCacheLineSize();
 }