Allocation Info Tracking, continued.

src/ia32/code-stubs-ia32.cc

 // Copyright 2012 the V8 project authors. All rights reserved.
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
 //       notice, this list of conditions and the following disclaimer.
 //     * Redistributions in binary form must reproduce the above
 //       copyright notice, this list of conditions and the following
 //       disclaimer in the documentation and/or other materials provided
@@ skipping 19 matching lines @@
 #if defined(V8_TARGET_ARCH_IA32)
 
 #include "bootstrapper.h"
 #include "code-stubs.h"
 #include "isolate.h"
 #include "jsregexp.h"
 #include "regexp-macro-assembler.h"
 #include "runtime.h"
 #include "stub-cache.h"
 #include "codegen.h"
+#include "runtime.h"
 
 namespace v8 {
 namespace internal {
 
 
 void KeyedLoadFastElementStub::InitializeInterfaceDescriptor(
     Isolate* isolate,
     CodeStubInterfaceDescriptor* descriptor) {
   static Register registers[] = { edx, ecx };
   descriptor->register_param_count_ = 2;
+  descriptor->stack_parameter_count_ = NULL;

[Toon Verwaest, 2013/02/13 15:14:51]

Unnecessary move.

   descriptor->register_params_ = registers;
-  descriptor->stack_parameter_count_ = NULL;
   descriptor->deoptimization_handler_ =
       FUNCTION_ADDR(KeyedLoadIC_MissFromStubFailure);
 }
 
 
 void TransitionElementsKindStub::InitializeInterfaceDescriptor(
     Isolate* isolate,
     CodeStubInterfaceDescriptor* descriptor) {
   static Register registers[] = { eax, ebx };

[Toon Verwaest, 2013/02/13 15:14:51]

Please write a comment above identifying the purpose of these registers.

[mvstanton, 2013/02/19 11:04:08]

I addressed this in the new function below,
InitializeArrayConstructorDescriptor().

   descriptor->register_param_count_ = 2;
   descriptor->register_params_ = registers;
   descriptor->deoptimization_handler_ =
       Runtime::FunctionForId(Runtime::kTransitionElementsKind)->entry;
 }
 
 
+static void InitializeArrayConstructorDescriptor(Isolate* isolate,
+    CodeStubInterfaceDescriptor* descriptor) {
+  static Register registers[] = { edi, ebx };
+  descriptor->register_param_count_ = 2;
+  // stack param count needs (constructor pointer, and single argument)
+  descriptor->stack_parameter_count_ = &eax;
+  descriptor->register_params_ = registers;
+  descriptor->extra_expression_stack_count_ = 1;
+  descriptor->deoptimization_handler_ =
+      FUNCTION_ADDR(ArrayConstructor_StubFailure);
+}
+
+
+void ArrayNoArgumentConstructorStub::InitializeInterfaceDescriptor(
+    Isolate* isolate,
+    CodeStubInterfaceDescriptor* descriptor) {
+  InitializeArrayConstructorDescriptor(isolate, descriptor);
+}
+
+
+void ArraySingleArgumentConstructorStub::InitializeInterfaceDescriptor(
+    Isolate* isolate,
+    CodeStubInterfaceDescriptor* descriptor) {
+  InitializeArrayConstructorDescriptor(isolate, descriptor);
+}
+
+
+void ArrayNArgumentsConstructorStub::InitializeInterfaceDescriptor(
+    Isolate* isolate,
+    CodeStubInterfaceDescriptor* descriptor) {
+  InitializeArrayConstructorDescriptor(isolate, descriptor);
+}
+
+
 #define __ ACCESS_MASM(masm)
 
 void ToNumberStub::Generate(MacroAssembler* masm) {
   // The ToNumber stub takes one argument in eax.
   Label check_heap_number, call_builtin;
   __ JumpIfNotSmi(eax, &check_heap_number, Label::kNear);
   __ ret(0);
 
   __ bind(&check_heap_number);
   __ mov(ebx, FieldOperand(eax, HeapObject::kMapOffset));
@@ skipping 4725 matching lines @@
 }
 
 
 static void GenerateRecordCallTarget(MacroAssembler* masm) {
   // Cache the called function in a global property cell.  Cache states
   // are uninitialized, monomorphic (indicated by a JSFunction), and
   // megamorphic.
   // ebx : cache cell for call target
   // edi : the function to call
   Isolate* isolate = masm->isolate();
-  Label initialize, done;
+  Label initialize, done, miss, megamorphic, not_array_function;
 
   // Load the cache state into ecx.
   __ mov(ecx, FieldOperand(ebx, JSGlobalPropertyCell::kValueOffset));
 
   // A monomorphic cache hit or an already megamorphic state: invoke the
   // function without changing the state.
   __ cmp(ecx, edi);
-  __ j(equal, &done, Label::kNear);
+  __ j(equal, &done, Label::kFar);

[Toon Verwaest, 2013/02/13 15:14:51]

I believe Label::kFar is the default, you can omit it if so.

[mvstanton, 2013/02/19 11:04:08]

Done.

   __ cmp(ecx, Immediate(TypeFeedbackCells::MegamorphicSentinel(isolate)));
-  __ j(equal, &done, Label::kNear);
+  __ j(equal, &done, Label::kFar);
+
+  // Special handling of the Array() function, which caches not only the
+  // monomorphic Array function but the initial ElementsKind with special
+  // sentinels
+  Handle<Object> terminal_kind_sentinel =
+      TypeFeedbackCells::MonomorphicArraySentinel(LAST_FAST_ELEMENTS_KIND);
+  __ cmp(ecx, Immediate(terminal_kind_sentinel));
+  __ j(above, &miss, Label::kFar);

[Toon Verwaest, 2013/02/13 15:14:51]

If you move this below the cmp, you can probably merge it with the equivalent
checks below.

[mvstanton, 2013/02/19 11:04:08]

I looked more carefully and it didn't seem possible without burning another
register which I don't want to do. Instead I made a macro assembler method to do
this: LoadGlobalContext(reg).

+  // Load the global or builtins object from the current context
+  __ mov(ecx, Operand(esi, Context::SlotOffset(Context::GLOBAL_OBJECT_INDEX)));
+  __ mov(ecx, FieldOperand(ecx, GlobalObject::kGlobalContextOffset));
+  // Make sure the function is the Array() function
+  __ cmp(edi, Operand(ecx,
+                      Context::SlotOffset(Context::ARRAY_FUNCTION_INDEX)));
+  Label megamorphic_pre;
+  __ j(not_equal, &megamorphic_pre, Label::kFar);

[Toon Verwaest, 2013/02/13 15:14:51]

Jump to megamorphic directly.

[mvstanton, 2013/02/19 11:04:08]

Done.

+  __ jmp(&done);
+
+  __ bind(&megamorphic_pre);
+  __ jmp(&megamorphic, Label::kFar);
+
+  __ bind(&miss);
 
   // A monomorphic miss (i.e, here the cache is not uninitialized) goes
   // megamorphic.
   __ cmp(ecx, Immediate(TypeFeedbackCells::UninitializedSentinel(isolate)));
-  __ j(equal, &initialize, Label::kNear);
+  __ j(equal, &initialize, Label::kFar);
   // MegamorphicSentinel is an immortal immovable object (undefined) so no
   // write-barrier is needed.
+  __ bind(&megamorphic);
   __ mov(FieldOperand(ebx, JSGlobalPropertyCell::kValueOffset),
          Immediate(TypeFeedbackCells::MegamorphicSentinel(isolate)));
   __ jmp(&done, Label::kNear);
 
-  // An uninitialized cache is patched with the function.
+  // An uninitialized cache is patched with the function or sentinel to
+  // indicate the ElementsKind if function is the Array constructor.
   __ bind(&initialize);
+  __ mov(ecx, Operand(esi, Context::SlotOffset(Context::GLOBAL_OBJECT_INDEX)));
+  __ mov(ecx, FieldOperand(ecx, GlobalObject::kGlobalContextOffset));

[Toon Verwaest, 2013/02/13 15:14:51]

Check if this can be folded together with the code above.

[mvstanton, 2013/02/19 11:04:08]

Not foldable, but I have a new macro method: LoadGlobalContext(reg).

+  // Make sure the function is the Array() function
+  __ cmp(edi, Operand(ecx,
+                      Context::SlotOffset(Context::ARRAY_FUNCTION_INDEX)));
+  __ j(not_equal, &not_array_function);
+
+  // The target function is the Array constructor, install a sentinel value in
+  // the constructor's type info cell that will track the initial ElementsKind
+  // that should be used for the array when its constructed.
+  Handle<Object> initial_kind_sentinel =
+      TypeFeedbackCells::MonomorphicArraySentinel(
+          GetInitialFastElementsKind());
+  __ mov(FieldOperand(ebx, JSGlobalPropertyCell::kValueOffset),
+         Immediate(initial_kind_sentinel));
+  __ jmp(&done);
+
+  __ bind(&not_array_function);
   __ mov(FieldOperand(ebx, JSGlobalPropertyCell::kValueOffset), edi);
   // No need for a write barrier here - cells are rescanned.
 
   __ bind(&done);
 }
 
 
 void CallFunctionStub::Generate(MacroAssembler* masm) {
   // ebx : cache cell for call target
   // edi : the function to call
@@ skipping 95 matching lines @@
   __ JumpIfSmi(edi, &non_function_call);
   // Check that function is a JSFunction.
   __ CmpObjectType(edi, JS_FUNCTION_TYPE, ecx);
   __ j(not_equal, &slow);
 
   if (RecordCallTarget()) {
     GenerateRecordCallTarget(masm);
   }
 
   // Jump to the function-specific construct stub.
-  __ mov(ebx, FieldOperand(edi, JSFunction::kSharedFunctionInfoOffset));
-  __ mov(ebx, FieldOperand(ebx, SharedFunctionInfo::kConstructStubOffset));
-  __ lea(ebx, FieldOperand(ebx, Code::kHeaderSize));
-  __ jmp(ebx);
+  __ mov(ecx, FieldOperand(edi, JSFunction::kSharedFunctionInfoOffset));
+  __ mov(ecx, FieldOperand(ecx, SharedFunctionInfo::kConstructStubOffset));
+  __ lea(ecx, FieldOperand(ecx, Code::kHeaderSize));
+  __ jmp(ecx);
 
   // edi: called object
   // eax: number of arguments
   // ecx: object map
   Label do_call;
   __ bind(&slow);
   __ CmpInstanceType(ecx, JS_FUNCTION_PROXY_TYPE);
   __ j(not_equal, &non_function_call);
   __ GetBuiltinEntry(edx, Builtins::CALL_FUNCTION_PROXY_AS_CONSTRUCTOR);
   __ jmp(&do_call);
@@ skipping 2732 matching lines @@
   // Restore ecx.
   __ pop(ecx);
   __ ret(0);
 }
 
 #undef __
 
 } }  // namespace v8::internal
 
 #endif  // V8_TARGET_ARCH_IA32