diff --git a/clang/lib/CodeGen/CGCall.cpp b/clang/lib/CodeGen/CGCall.cpp
--- a/clang/lib/CodeGen/CGCall.cpp
+++ b/clang/lib/CodeGen/CGCall.cpp
@@ -1296,12 +1296,16 @@
 // FIXME: Do we need to recurse here?
 void CodeGenFunction::EmitAggregateStore(llvm::Value *Val, Address Dest,
                                          bool DestIsVolatile) {
-  // Prefer scalar stores to first-class aggregate stores.
   if (llvm::StructType *STy = dyn_cast<llvm::StructType>(Val->getType())) {
-    for (unsigned i = 0, e = STy->getNumElements(); i != e; ++i) {
-      Address EltPtr = Builder.CreateStructGEP(Dest, i);
-      llvm::Value *Elt = Builder.CreateExtractValue(Val, i);
-      Builder.CreateStore(Elt, EltPtr, DestIsVolatile);
+    if (STy->containsScalableVectorType())
+      Builder.CreateStore(Val, Dest, DestIsVolatile);
+    else {
+      // Prefer scalar stores to first-class aggregate stores.
+      for (unsigned i = 0, e = STy->getNumElements(); i != e; ++i) {
+        Address EltPtr = Builder.CreateStructGEP(Dest, i);
+        llvm::Value *Elt = Builder.CreateExtractValue(Val, i);
+        Builder.CreateStore(Elt, EltPtr, DestIsVolatile);
+      }
     }
   } else {
     Builder.CreateStore(Val, Dest, DestIsVolatile);
@@ -2857,11 +2861,21 @@
         }
 
         assert(STy->getNumElements() == NumIRArgs);
-        for (unsigned i = 0, e = STy->getNumElements(); i != e; ++i) {
-          auto AI = Fn->getArg(FirstIRArg + i);
-          AI->setName(Arg->getName() + ".coerce" + Twine(i));
-          Address EltPtr = Builder.CreateStructGEP(AddrToStoreInto, i);
-          Builder.CreateStore(AI, EltPtr);
+        if (STy->containsScalableVectorType()) {
+          llvm::Value *Val = llvm::UndefValue::get(STy);
+          for (unsigned i = 0, e = STy->getNumElements(); i != e; ++i) {
+            auto AI = Fn->getArg(FirstIRArg + i);
+            AI->setName(Arg->getName() + ".coerce" + Twine(i));
+            Val = Builder.CreateInsertValue(Val, AI, i);
+          }
+          Builder.CreateStore(Val, AddrToStoreInto);
+        } else {
+          for (unsigned i = 0, e = STy->getNumElements(); i != e; ++i) {
+            auto AI = Fn->getArg(FirstIRArg + i);
+            AI->setName(Arg->getName() + ".coerce" + Twine(i));
+            Address EltPtr = Builder.CreateStructGEP(AddrToStoreInto, i);
+            Builder.CreateStore(AI, EltPtr);
+          }
         }
 
         if (SrcSize > DstSize) {
@@ -4920,10 +4934,18 @@
         }
 
         assert(NumIRArgs == STy->getNumElements());
-        for (unsigned i = 0, e = STy->getNumElements(); i != e; ++i) {
-          Address EltPtr = Builder.CreateStructGEP(Src, i);
-          llvm::Value *LI = Builder.CreateLoad(EltPtr);
-          IRCallArgs[FirstIRArg + i] = LI;
+        if (STy->containsScalableVectorType()) {
+          llvm::Value *Val = Builder.CreateLoad(Src);
+          for (unsigned i = 0, e = STy->getNumElements(); i != e; ++i) {
+            llvm::Value *LI = Builder.CreateExtractValue(Val, i);
+            IRCallArgs[FirstIRArg + i] = LI;
+          }
+        } else {
+          for (unsigned i = 0, e = STy->getNumElements(); i != e; ++i) {
+            Address EltPtr = Builder.CreateStructGEP(Src, i);
+            llvm::Value *LI = Builder.CreateLoad(EltPtr);
+            IRCallArgs[FirstIRArg + i] = LI;
+          }
         }
       } else {
         // In the simple case, just pass the coerced loaded value.