VM: Improve receiver class check in polymorphic inlining.

runtime/vm/intermediate_language_x64.cc

Index: runtime/vm/intermediate_language_x64.cc
===================================================================
--- runtime/vm/intermediate_language_x64.cc	(revision 33059)
+++ runtime/vm/intermediate_language_x64.cc	(working copy)
@@ -4721,6 +4721,33 @@
 }
 
 
+LocationSummary* CheckClassIdInstr::MakeLocationSummary(bool opt) const {
+  const intptr_t kNumInputs = 2;
+  const intptr_t kNumTemps = 0;
+  LocationSummary* summary =
+      new LocationSummary(kNumInputs, kNumTemps, LocationSummary::kNoCall);
+  summary->set_in(0, Location::RequiresRegister());
+  summary->set_in(1, Location::RegisterOrSmiConstant(right()));
+  return summary;
+}
+
+
+void CheckClassIdInstr::EmitNativeCode(FlowGraphCompiler* compiler) {
+  Register left = locs()->in(0).reg();
+  Location right = locs()->in(1);
+  Label* deopt = compiler->AddDeoptStub(deopt_id(), kDeoptCheckClass);
+  if (right.IsRegister()) {
+    __ cmpq(left, right.reg());
+  } else {
+    ASSERT(right.IsConstant());
+    const Object& right_const = Smi::Cast(right.constant());
+    __ CompareImmediate(
+        left, Immediate(reinterpret_cast<int64_t>(right_const.raw())), PP);
+  }
+  __ j(NOT_ZERO, deopt);
+}
+
+
 LocationSummary* CheckArrayBoundInstr::MakeLocationSummary(bool opt) const {
   const intptr_t kNumInputs = 2;
   const intptr_t kNumTemps = 0;