Replace class with class ids inside ICData

runtime/vm/stub_code_x64.cc

 // Copyright (c) 2012, 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_X64)
 
 #include "vm/assembler.h"
 #include "vm/assembler_macros.h"
 #include "vm/code_generator.h"
@@ skipping 1547 matching lines @@
     __ popq(RBX);  // Restore inline cache data object.
     __ 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).
   __ movq(RAX, FieldAddress(R10, Array::data_offset()));
   __ movq(RAX, Address(RSP, RAX, TIMES_4, 0));  // RAX (argument count) is Smi.
 
-  Label get_class, ic_miss;
+  Label get_class_id_as_smi, ic_miss;
   // RBX: 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.
     __ movq(RCX, FieldAddress(RBX, ICData::num_args_tested_offset()));
     __ cmpq(RCX, 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.
   // RBX: IC data object (preserved).
   __ movq(R12, FieldAddress(RBX, ICData::ic_data_offset()));
   // R12: ic_data_array with check entries: classes and target functions.
   __ leaq(R12, FieldAddress(R12, Array::data_offset()));
   // R12: points directly to the first ic data array element.
   const Immediate raw_null =
       Immediate(reinterpret_cast<intptr_t>(Object::null()));
   Label loop, found;
   if (num_args == 1) {
-    __ call(&get_class);
-    // RAX: receiver's class.
+    __ call(&get_class_id_as_smi);
+    // RAX: receiver's class id as Smi.
     __ Bind(&loop);
-    __ movq(R13, Address(R12, 0));  // Get class to check.
+    __ movq(R13, Address(R12, 0));  // Get class if (Smi) to check.
     __ cmpq(RAX, R13);  // Match?
     __ j(EQUAL, &found, Assembler::kNearJump);
     __ addq(R12, Immediate(kWordSize * 2));  // Next element (class + target).
     __ cmpq(R13, raw_null);   // Done?
     __ j(NOT_EQUAL, &loop, Assembler::kNearJump);
   } else if (num_args == 2) {
     Label no_match;
     __ Bind(&loop);
     // Get receiver.
     __ movq(RAX, FieldAddress(R10, Array::data_offset()));
     __ movq(RAX, Address(RSP, RAX, TIMES_4, 0));  // RAX is Smi.
-    __ call(&get_class);
-    // TODO(vegorov): switch IC data to store class index instead of class.
-    __ movq(R13, Address(R12, 0));  // Get class from IC data to check.
-    __ cmpq(RAX, R13);  // Match?
+    __ call(&get_class_id_as_smi);
+    __ movq(R13, Address(R12, 0));  // Get class id from IC data to check.
+    __ cmpq(RAX, R13);  // Class id match?
     __ j(NOT_EQUAL, &no_match, Assembler::kNearJump);
     // Check second.
     // Get next argument.
     __ movq(RAX, FieldAddress(R10, Array::data_offset()));
     __ movq(RAX, Address(RSP, RAX, TIMES_4, -kWordSize));  // RAX is Smi.
-    __ call(&get_class);
-    __ movq(R13, Address(R12, kWordSize));  // Get class from IC data to check.
-    __ cmpq(RAX, R13);  // Match?
+    __ call(&get_class_id_as_smi);
+    __ movq(R13, Address(R12, kWordSize));  // Get class id from IC data.
+    __ cmpq(RAX, R13);  //  Class id match?
     __ j(EQUAL, &found);
     __ Bind(&no_match);
     __ addq(R12, Immediate(kWordSize * (1 + num_args)));  // Next element.
     __ cmpq(R13, raw_null);   // Done?
     __ j(NOT_EQUAL, &loop, Assembler::kNearJump);
   }
 
   __ Bind(&ic_miss);
   // Compute address of arguments (first read number of arguments from argument
   // descriptor array and then compute address on the stack).
@@ skipping 33 matching lines @@
   // R12: Pointer to an IC data check group (classes + target)
   __ movq(RAX, Address(R12, kWordSize * num_args));  // Target function.
 
   __ Bind(&call_target_function);
   // RAX: Target function.
   __ movq(RAX, FieldAddress(RAX, Function::code_offset()));
   __ movq(RAX, FieldAddress(RAX, Code::instructions_offset()));
   __ addq(RAX, Immediate(Instructions::HeaderSize() - kHeapObjectTag));
   __ jmp(RAX);
 
-  __ Bind(&get_class);
+  __ Bind(&get_class_id_as_smi);
   Label not_smi;
   // Test if Smi -> load Smi class for comparison.
   __ testq(RAX, Immediate(kSmiTagMask));
   __ j(NOT_ZERO, &not_smi, Assembler::kNearJump);
-  const Class& smi_class =
-      Class::ZoneHandle(Isolate::Current()->object_store()->smi_class());
-  __ LoadObject(RAX, smi_class);
+  __ movq(RAX, Immediate(Smi::RawValue(kSmi)));
   __ ret();
 
   __ Bind(&not_smi);
-  __ LoadClass(RAX, RAX);
+  __ LoadClassId(RAX, RAX);
+  __ SmiTag(RAX);
   __ ret();
 }
 
 
 // Use inline cache data array to invoke the target or continue in inline
 // cache miss handler. Stub for 1-argument check (receiver class).
 //  RCX: Inline cache data array
 //  RDX: Arguments array
 //  TOS(0): return address
 // Inline cache data array structure:
@@ skipping 172 matching lines @@
 // TOS + 2: instance.
 // TOS + 3: cache array.
 // Result in RCX: null -> not found, otherwise result (true or false).
 void StubCode::GenerateSubtype3TestCacheStub(Assembler* assembler) {
   GenerateSubtypeNTestCacheStub(assembler, 3);
 }
 
 }  // namespace dart
 
 #endif  // defined TARGET_ARCH_X64