[turbofan]: Elide extra move when accessing stack or frame register

test/cctest/compiler/test-run-stubs.cc

 // Copyright 2015 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "src/bootstrapper.h"
 #include "src/code-stubs.h"
 #include "src/compiler/common-operator.h"
 #include "src/compiler/graph.h"
 #include "src/compiler/js-graph.h"
 #include "src/compiler/js-operator.h"
@@ skipping 46 matching lines @@
   graph.SetStart(start);
   graph.SetEnd(end);
   FunctionTester ft(&graph);
 
   Handle<Object> value = ft.Val(1.5);
   Handle<Object> result = ft.Call(value, value).ToHandleChecked();
   CHECK_EQ(1, Smi::cast(*result)->value());
 }
 
 
+TEST(RunUnoptimizedMathFloorStub) {
+  HandleAndZoneScope scope;
+  Isolate* isolate = scope.main_isolate();
+
+  // Create code and an accompanying descriptor.
+  MathFloorStub stub(isolate, TurboFanIC::CALL_FROM_UNOPTIMIZED_CODE);
+  stub.GenerateCode();
+}
+
+
 TEST(RunStringLengthTFStub) {
   HandleAndZoneScope scope;
   Isolate* isolate = scope.main_isolate();
   Zone* zone = scope.main_zone();
 
   // Create code and an accompanying descriptor.
   StringLengthTFStub stub(isolate);
   Handle<Code> code = stub.GenerateCode();
   CompilationInfo info(&stub, isolate, zone);
   CallDescriptor* descriptor = Linkage::ComputeIncoming(zone, &info);
@@ skipping 64 matching lines @@
   FunctionTester ft(&graph);
 
   // Actuall call through to the stub, verifying its result.
   Handle<String> leftArg = ft.Val("links");
   Handle<String> rightArg = ft.Val("rechts");
   Handle<Object> result = ft.Call(leftArg, rightArg).ToHandleChecked();
   CHECK(String::Equals(ft.Val("linksrechts"), Handle<String>::cast(result)));
 }
 
 #endif  // V8_TURBOFAN_TARGET