X64: Use low bits of registers in emit_sse_operand. Enable --stop-at flag.

src/x64/codegen-x64.cc

 // Copyright 2009 the V8 project authors. All rights reserved.
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
 //       notice, this list of conditions and the following disclaimer.
 //     * Redistributions in binary form must reproduce the above
 //       copyright notice, this list of conditions and the following
 //       disclaimer in the documentation and/or other materials provided
@@ skipping 136 matching lines @@
   frame_ = new VirtualFrame();
   set_in_spilled_code(false);
 
   // Adjust for function-level loop nesting.
   loop_nesting_ += function->loop_nesting();
 
   JumpTarget::set_compiling_deferred_code(false);
 
 #ifdef DEBUG
   if (strlen(FLAG_stop_at) > 0 &&
-      //    fun->name()->IsEqualTo(CStrVector(FLAG_stop_at))) {
-      false) {
+      function->name()->IsEqualTo(CStrVector(FLAG_stop_at))) {
     frame_->SpillAll();
     __ int3();
   }
 #endif
 
   // New scope to get automatic timing calculation.
   {  // NOLINT
     HistogramTimerScope codegen_timer(&Counters::code_generation);
     CodeGenState state(this);
 
@@ skipping 6771 matching lines @@
 int CompareStub::MinorKey() {
   // Encode the two parameters in a unique 16 bit value.
   ASSERT(static_cast<unsigned>(cc_) < (1 << 15));
   return (static_cast<unsigned>(cc_) << 1) | (strict_ ? 1 : 0);
 }
 
 
 #undef __
 
 } }  // namespace v8::internal