Hydrogen code stubs for vector-based ICs.

src/x64/code-stubs-x64.cc

Index: src/x64/code-stubs-x64.cc
diff --git a/src/x64/code-stubs-x64.cc b/src/x64/code-stubs-x64.cc
index f17389cc95a382f934348d72ca75c49a6f0ed6a4..da72c29f3b434a817f80efe650a727fe71cb3183 100644
--- a/src/x64/code-stubs-x64.cc
+++ b/src/x64/code-stubs-x64.cc
@@ -524,6 +524,11 @@ void MathPowStub::Generate(MacroAssembler* masm) {
 void FunctionPrototypeStub::Generate(MacroAssembler* masm) {
   Label miss;
   Register receiver = LoadDescriptor::ReceiverRegister();
+  // Ensure that the vector and slot registers won't be clobbered before
+  // calling the miss handler.
+  DCHECK(!FLAG_vector_ics ||
+         !AreAliased(r8, r9, VectorLoadICDescriptor::VectorRegister(),
+                     VectorLoadICDescriptor::SlotRegister()));
 
   NamedLoadHandlerCompiler::GenerateLoadFunctionPrototype(masm, receiver, r8,
                                                           r9, &miss);
@@ -873,10 +878,16 @@ void LoadIndexedStringStub::Generate(MacroAssembler* masm) {
 
   Register receiver = LoadDescriptor::ReceiverRegister();
   Register index = LoadDescriptor::NameRegister();
-  Register scratch = rbx;
+  Register scratch = rdi;
   Register result = rax;
   DCHECK(!scratch.is(receiver) && !scratch.is(index));
+  DCHECK(!FLAG_vector_ics ||
+         (!scratch.is(VectorLoadICDescriptor::VectorRegister()) &&
+          result.is(VectorLoadICDescriptor::SlotRegister())));
 
+  // StringCharAtGenerator doesn't use the result register until it's passed
+  // the different miss possibilities. If it did, we would have a conflict
+  // when FLAG_vector_ics is true.
   StringCharAtGenerator char_at_generator(receiver, index, scratch, result,
                                           &miss,  // When not a string.
                                           &miss,  // When not a number.