Added flag --inline_smi_string_hashcode and --inline_smi_string_hashcode_ratio to decide when/if sh…

runtime/vm/flow_graph_compiler_x64.cc

 // Copyright (c) 2013, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 #include "vm/globals.h"  // Needed here to get TARGET_ARCH_X64.
 #if defined(TARGET_ARCH_X64)
 
 #include "vm/flow_graph_compiler.h"
 
 #include "vm/ast_printer.h"
@@ skipping 1314 matching lines @@
   const String& name = String::Handle(zone(), ic_data.target_name());
   const Array& arguments_descriptor =
       Array::ZoneHandle(zone(), ic_data.arguments_descriptor());
   ASSERT(!arguments_descriptor.IsNull() && (arguments_descriptor.Length() > 0));
   const MegamorphicCache& cache = MegamorphicCache::ZoneHandle(zone(),
       MegamorphicCacheTable::Lookup(isolate(), name, arguments_descriptor));
   __ Comment("MegamorphicCall");
   // Load receiver into RDI.
   __ movq(RDI, Address(RSP, (argument_count - 1) * kWordSize));
   Label done;
-  if (name.raw() == Symbols::hashCode().raw()) {
-    Label try_onebytestring, megamorphic_call;
+  if (ShouldInlineSmiStringHashCode(ic_data)) {
+    Label megamorphic_call;
     __ Comment("Inlined get:hashCode for Smi and OneByteString");
+    __ movq(RAX, RDI);  // Move Smi hashcode to RAX.
     __ testq(RDI, Immediate(kSmiTagMask));
-    __ j(NOT_ZERO, &try_onebytestring, Assembler::kNearJump);  // Non-smi value.
-    __ movq(RAX, RDI);
-    __ jmp(&done, Assembler::kNearJump);
+    __ j(ZERO, &done, Assembler::kNearJump);  // It is Smi, we are done.
 
-    __ Bind(&try_onebytestring);
     __ CompareClassId(RDI, kOneByteStringCid);
     __ j(NOT_EQUAL, &megamorphic_call, Assembler::kNearJump);
     __ movq(RAX, FieldAddress(RDI, String::hash_offset()));
     __ cmpq(RAX, Immediate(0));
     __ j(NOT_EQUAL, &done, Assembler::kNearJump);
 
     __ Bind(&megamorphic_call);
     __ Comment("Slow case: megamorphic call");
   }
   __ LoadObject(RBX, cache);
@@ skipping 516 matching lines @@
   __ movups(reg, Address(RSP, 0));
   __ AddImmediate(RSP, Immediate(kFpuRegisterSize));
 }
 
 
 #undef __
 
 }  // namespace dart
 
 #endif  // defined TARGET_ARCH_X64