This is https://chromiumcodereview.appspot.com/10581006/ that I forgot to submit, and messed up the…

runtime/vm/stub_code_ia32.cc

 // Copyright (c) 2011, 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"
 #if defined(TARGET_ARCH_IA32)
 
 #include "vm/assembler.h"
 #include "vm/assembler_macros.h"
 #include "vm/code_generator.h"
@@ skipping 1534 matching lines @@
 //  ECX: Inline cache data object.
 //  EDX: Arguments descriptor array.
 //  TOS(0): return address
 // Control flow:
 // - If receiver is null -> jump to IC miss.
 // - If receiver is Smi -> load Smi class.
 // - If receiver is not-Smi -> load receiver's class.
 // - Check if 'num_args' (including receiver) match any IC data group.
 // - Match found -> jump to target.
 // - Match not found -> jump to IC miss.
+// TODO(srdjan): Change IC data to keep class ids as integers not as Smi-s.
 void StubCode::GenerateNArgsCheckInlineCacheStub(Assembler* assembler,
                                                  intptr_t num_args) {
   const Immediate raw_null =
       Immediate(reinterpret_cast<intptr_t>(Object::null()));
 
   __ movl(EBX, FieldAddress(ECX, ICData::function_offset()));
   __ incl(FieldAddress(EBX, Function::usage_counter_offset()));
   if (CodeGenerator::CanOptimize()) {
     __ cmpl(FieldAddress(EBX, Function::usage_counter_offset()),
         Immediate(FLAG_optimization_counter_threshold));
@@ skipping 12 matching lines @@
     __ LeaveFrame();
     __ Bind(&not_yet_hot);
   }
 
   ASSERT(num_args > 0);
   // Get receiver (first read number of arguments from argument descriptor array
   // and then access the receiver from the stack).
   __ movl(EAX, FieldAddress(EDX, Array::data_offset()));
   __ movl(EAX, Address(ESP, EAX, TIMES_2, 0));  // EAX (argument_count) is Smi.
 
-  Label get_class, ic_miss;
+  Label get_class_id_as_smi, ic_miss;
   // ECX: IC data array.
 
 #if defined(DEBUG)
   { Label ok;
     // Check that the IC data array has NumberOfArgumentsChecked() == num_args.
     // 'num_args_tested' is stored as an untagged int.
     __ movl(EBX, FieldAddress(ECX, ICData::num_args_tested_offset()));
     __ cmpl(EBX, Immediate(num_args));
     __ j(EQUAL, &ok, Assembler::kNearJump);
     __ Stop("Incorrect stub for IC data");
     __ Bind(&ok);
   }
 #endif  // DEBUG
 
   // Loop that checks if there is an IC data match.
   // ECX: IC data object (preserved).
   __ movl(EBX, FieldAddress(ECX, ICData::ic_data_offset()));
   // EBX: ic_data_array with check entries: classes and target functions.
   __ leal(EBX, FieldAddress(EBX, Array::data_offset()));
   // EBX: points directly to the first ic data array element.
   Label loop, found;
   if (num_args == 1) {
-    __ call(&get_class);
-    // EAX: receiver's class
+    __ call(&get_class_id_as_smi);
+    // EAX: receiver's class id Smi.
     __ Bind(&loop);
-    __ movl(EDI, Address(EBX, 0));  // Get class to check.
-    __ cmpl(EAX, EDI);  // Match?
+    __ movl(EDI, Address(EBX, 0));  // Get class id (Smi) to check.
+    __ cmpl(EAX, EDI);  // Class id match?
     __ j(EQUAL, &found, Assembler::kNearJump);
     __ addl(EBX, Immediate(kWordSize * 2));  // Next element (class + target).
     __ cmpl(EDI, raw_null);   // Done?
     __ j(NOT_EQUAL, &loop, Assembler::kNearJump);
   } else if (num_args == 2) {
     // EDI: class to check.
     Label no_match;
     __ Bind(&loop);
-    // Get class from IC data to check.
+    // Get class id from IC data to check.
     // Get receiver using argument descriptor in EDX.
     __ movl(EAX, FieldAddress(EDX, Array::data_offset()));
     __ movl(EAX, Address(ESP, EAX, TIMES_2, 0));  // EAX (arg. count) is Smi.
-    __ call(&get_class);
-    // TODO(vegorov): switch IC data to store class index instead of class.
+    __ call(&get_class_id_as_smi);
     __ movl(EDI, Address(EBX, 0));
-    __ cmpl(EAX, EDI);  // Match?
+    __ cmpl(EAX, EDI);  // Class id match?
     __ j(NOT_EQUAL, &no_match, Assembler::kNearJump);
     // Check second class/argument.
-    // Get class from IC data to check.
+    // Get class id from IC data to check.
     // Get next argument.
     __ movl(EAX, FieldAddress(EDX, Array::data_offset()));
     __ movl(EAX, Address(ESP, EAX, TIMES_2, -kWordSize));
     // EAX (argument count) is Smi.
-    __ call(&get_class);
+    __ call(&get_class_id_as_smi);
     __ movl(EDI, Address(EBX, kWordSize));
-    __ cmpl(EAX, EDI);  // Match?
+    __ cmpl(EAX, EDI);  // Class id match?
     __ j(EQUAL, &found, Assembler::kNearJump);
     __ Bind(&no_match);
     // Each test entry has (1 + num_args) array elements.
     __ addl(EBX, Immediate(kWordSize * (1 + num_args)));  // Next element.
     __ cmpl(EDI, raw_null);   // Done?
     __ j(NOT_EQUAL, &loop, Assembler::kNearJump);
   }
 
   __ Bind(&ic_miss);
   // Compute address of arguments (first read number of arguments from argument
@@ skipping 36 matching lines @@
   // EBX: Pointer to an IC data check group (classes + target)
   __ movl(EAX, Address(EBX, kWordSize * num_args));  // Target function.
 
   __ Bind(&call_target_function);
   // EAX: Target function.
   __ movl(EAX, FieldAddress(EAX, Function::code_offset()));
   __ movl(EAX, FieldAddress(EAX, Code::instructions_offset()));
   __ addl(EAX, Immediate(Instructions::HeaderSize() - kHeapObjectTag));
   __ jmp(EAX);
 
-  __ Bind(&get_class);
+  __ Bind(&get_class_id_as_smi);
   Label not_smi;
   // Test if Smi -> load Smi class for comparison.
   __ testl(EAX, Immediate(kSmiTagMask));
   __ j(NOT_ZERO, &not_smi, Assembler::kNearJump);
-  const Class& smi_class =
-      Class::ZoneHandle(Isolate::Current()->object_store()->smi_class());
-  __ LoadObject(EAX, smi_class);
+  __ movl(EAX, Immediate(Smi::RawValue(kSmi)));
   __ ret();
 
   __ Bind(&not_smi);
-  __ LoadClass(EAX, EAX, EDI);
+  __ LoadClassId(EAX, EAX);
+  __ SmiTag(EAX);
   __ ret();
 }
 
 
 // Use inline cache data array to invoke the target or continue in inline
 // cache miss handler. Stub for 1-argument check (receiver class).
 //  ECX: Inline cache data array
 //  EDX: Arguments array
 //  TOS(0): return address
 // Inline cache data array structure:
@@ skipping 181 matching lines @@
 // TOS + 2: instance.
 // TOS + 3: cache array.
 // Result in ECX: null -> not found, otherwise result (true or false).
 void StubCode::GenerateSubtype3TestCacheStub(Assembler* assembler) {
   GenerateSubtypeNTestCacheStub(assembler, 3);
 }
 
 }  // namespace dart
 
 #endif  // defined TARGET_ARCH_IA32