[SLP] Load sorting should not try to sort things that aren't loads.

We may get a VL where the first element is a load, but the others
aren't. Trying to sort such VLs can only lead to sorrow.

llvm-svn: 296411

llvm/lib/Analysis/LoopAccessAnalysis.cpp

@@ -1052,7 +1052,12 @@ bool llvm::sortMemAccesses(ArrayRef<Value *> VL, const DataLayout &DL,
   Value *Obj0 = GetUnderlyingObject(Ptr0, DL);
 
   for (auto *Val : VL) {
+    // The only kind of access we care about here is load.
+    if (!isa<LoadInst>(Val))
+      return false;
+
     Value *Ptr = getPointerOperand(Val);
+    assert(Ptr && "Expected value to have a pointer operand.");
 
     // If a pointer refers to a different underlying object, bail - the
     // pointers are by definition incomparable.