Second attempt at introducing a premonomorphic state in the call

target caches.

This time we don't go through the premonomorphic state for
the Array call target caches to avoid losing information from
allocation sites that aren't only used once, but where the
resulting array is used heavily.

R=mvstanton@chromium.org

Review URL: https://codereview.chromium.org/169683003

Patch from Kasper Lund <kasperl@chromium.org>.

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@19457 ce2b1a6d-e550-0410-aec6-3dcde31c8c00

diff --git a/src/a64/code-stubs-a64.cc b/src/a64/code-stubs-a64.cc
index a03459a844bf0e78269087979c4450e985e98b4c..b640677caee7bd87e22107d9bd2be681e7b23215 100644 (file)
--- a/src/a64/code-stubs-a64.cc
+++ b/src/a64/code-stubs-a64.cc
@@ -3265,12 +3265,17 @@ static void GenerateRecordCallTarget(MacroAssembler* masm) {
   //  x1 : the function to call
   //  x2 : feedback vector
   //  x3 : slot in feedback vector (smi)
-  Label initialize, done, miss, megamorphic, not_array_function;
+  Label check_array, initialize_array, initialize_non_array, megamorphic, done;
 
   ASSERT_EQ(*TypeFeedbackInfo::MegamorphicSentinel(masm->isolate()),
             masm->isolate()->heap()->undefined_value());
+  Heap::RootListIndex kMegamorphicRootIndex = Heap::kUndefinedValueRootIndex;
   ASSERT_EQ(*TypeFeedbackInfo::UninitializedSentinel(masm->isolate()),
             masm->isolate()->heap()->the_hole_value());
+  Heap::RootListIndex kUninitializedRootIndex = Heap::kTheHoleValueRootIndex;
+  ASSERT_EQ(*TypeFeedbackInfo::PremonomorphicSentinel(masm->isolate()),
+            masm->isolate()->heap()->null_value());
+  Heap::RootListIndex kPremonomorphicRootIndex = Heap::kNullValueRootIndex;
 
   // Load the cache state.
   __ Add(x4, x2, Operand::UntagSmiAndScale(x3, kPointerSizeLog2));
@@ -3280,43 +3285,44 @@ static void GenerateRecordCallTarget(MacroAssembler* masm) {
   // function without changing the state.
   __ Cmp(x4, x1);
   __ B(eq, &done);
+  __ JumpIfRoot(x4, kMegamorphicRootIndex, &done);
 
-  // If we came here, we need to see if we are the array function.
-  // If we didn't have a matching function, and we didn't find the megamorph
-  // sentinel, then we have in the slot either some other function or an
-  // AllocationSite. Do a map check on the object in ecx.
-  __ Ldr(x5, FieldMemOperand(x4, AllocationSite::kMapOffset));
-  __ JumpIfNotRoot(x5, Heap::kAllocationSiteMapRootIndex, &miss);
+  // Check if we're dealing with the Array function or not.
+  __ LoadArrayFunction(x5);
+  __ Cmp(x1, x5);
+  __ B(eq, &check_array);
+
+  // Non-array cache: Check the cache state.
+  __ JumpIfRoot(x4, kPremonomorphicRootIndex, &initialize_non_array);
+  __ JumpIfNotRoot(x4, kUninitializedRootIndex, &megamorphic);
 
-  // Make sure the function is the Array() function
-  __ LoadArrayFunction(x4);
-  __ Cmp(x1, x4);
-  __ B(ne, &megamorphic);
+  // Non-array cache: Uninitialized -> premonomorphic. The sentinel is an
+  // immortal immovable object (null) so no write-barrier is needed.
+  __ Add(x4, x2, Operand::UntagSmiAndScale(x3, kPointerSizeLog2));
+  __ LoadRoot(x10, kPremonomorphicRootIndex);
+  __ Str(x10, FieldMemOperand(x4, FixedArray::kHeaderSize));
   __ B(&done);
 
-  __ Bind(&miss);
+  // Array cache: Check the cache state to see if we're in a monomorphic
+  // state where the state object is an AllocationSite object.
+  __ Bind(&check_array);
+  __ Ldr(x5, FieldMemOperand(x4, AllocationSite::kMapOffset));
+  __ JumpIfRoot(x5, Heap::kAllocationSiteMapRootIndex, &done);
+
+  // Array cache: Uninitialized or premonomorphic -> monomorphic.
+  __ JumpIfRoot(x4, kUninitializedRootIndex, &initialize_array);
+  __ JumpIfRoot(x4, kPremonomorphicRootIndex, &initialize_array);
 
-  // A monomorphic miss (i.e, here the cache is not uninitialized) goes
-  // megamorphic.
-  __ JumpIfRoot(x4, Heap::kTheHoleValueRootIndex, &initialize);
-  // MegamorphicSentinel is an immortal immovable object (undefined) so no
-  // write-barrier is needed.
+  // Both caches: Monomorphic -> megamorphic. The sentinel is an
+  // immortal immovable object (undefined) so no write-barrier is needed.
   __ Bind(&megamorphic);
   __ Add(x4, x2, Operand::UntagSmiAndScale(x3, kPointerSizeLog2));
-  __ LoadRoot(x10, Heap::kUndefinedValueRootIndex);
+  __ LoadRoot(x10, kMegamorphicRootIndex);
   __ Str(x10, FieldMemOperand(x4, FixedArray::kHeaderSize));
   __ B(&done);
 
-  // An uninitialized cache is patched with the function or sentinel to
-  // indicate the ElementsKind if function is the Array constructor.
-  __ Bind(&initialize);
-  // Make sure the function is the Array() function
-  __ LoadArrayFunction(x4);
-  __ Cmp(x1, x4);
-  __ B(ne, &not_array_function);
-
-  // The target function is the Array constructor,
-  // Create an AllocationSite if we don't already have it, store it in the slot.
+  // Array cache: Uninitialized or premonomorphic -> monomorphic.
+  __ Bind(&initialize_array);
   {
     FrameScope scope(masm, StackFrame::INTERNAL);
     CreateAllocationSiteStub create_stub;
@@ -3332,9 +3338,8 @@ static void GenerateRecordCallTarget(MacroAssembler* masm) {
   }
   __ B(&done);
 
-  __ Bind(&not_array_function);
-  // An uninitialized cache is patched with the function.
-
+  // Non-array cache: Premonomorphic -> monomorphic.
+  __ Bind(&initialize_non_array);
   __ Add(x4, x2, Operand::UntagSmiAndScale(x3, kPointerSizeLog2));
   // TODO(all): Does the value need to be left in x4? If not, FieldMemOperand
   // could be used to avoid this add.
@@ -3347,7 +3352,6 @@ static void GenerateRecordCallTarget(MacroAssembler* masm) {
   __ Pop(x1, x2, x4);
 
   // TODO(all): Are x4, x2 and x1 outputs? This isn't clear.
-
   __ Bind(&done);
 }
 

diff --git a/src/arm/code-stubs-arm.cc b/src/arm/code-stubs-arm.cc
index b3a3acf3e76a36a2eccdf9aaaca9958fdbbce0e8..501b5c7dffab1af6439ff9c66f9407ffe612ba09 100644 (file)
--- a/src/arm/code-stubs-arm.cc
+++ b/src/arm/code-stubs-arm.cc
@@ -3012,12 +3012,17 @@ static void GenerateRecordCallTarget(MacroAssembler* masm) {
   // r1 : the function to call
   // r2 : Feedback vector
   // r3 : slot in feedback vector (Smi)
-  Label initialize, done, miss, megamorphic, not_array_function;
+  Label check_array, initialize_array, initialize_non_array, megamorphic, done;
 
   ASSERT_EQ(*TypeFeedbackInfo::MegamorphicSentinel(masm->isolate()),
             masm->isolate()->heap()->undefined_value());
+  Heap::RootListIndex kMegamorphicRootIndex = Heap::kUndefinedValueRootIndex;
   ASSERT_EQ(*TypeFeedbackInfo::UninitializedSentinel(masm->isolate()),
             masm->isolate()->heap()->the_hole_value());
+  Heap::RootListIndex kUninitializedRootIndex = Heap::kTheHoleValueRootIndex;
+  ASSERT_EQ(*TypeFeedbackInfo::PremonomorphicSentinel(masm->isolate()),
+            masm->isolate()->heap()->null_value());
+  Heap::RootListIndex kPremonomorphicRootIndex = Heap::kNullValueRootIndex;
 
   // Load the cache state into r4.
   __ add(r4, r2, Operand::PointerOffsetFromSmiKey(r3));
@@ -3027,45 +3032,50 @@ static void GenerateRecordCallTarget(MacroAssembler* masm) {
   // function without changing the state.
   __ cmp(r4, r1);
   __ b(eq, &done);
+  __ CompareRoot(r4, kMegamorphicRootIndex);
+  __ b(eq, &done);
 
-  // If we came here, we need to see if we are the array function.
-  // If we didn't have a matching function, and we didn't find the megamorph
-  // sentinel, then we have in the slot either some other function or an
-  // AllocationSite. Do a map check on the object in ecx.
-  __ ldr(r5, FieldMemOperand(r4, 0));
-  __ CompareRoot(r5, Heap::kAllocationSiteMapRootIndex);
-  __ b(ne, &miss);
+  // Check if we're dealing with the Array function or not.
+  __ LoadArrayFunction(r5);
+  __ cmp(r1, r5);
+  __ b(eq, &check_array);
 
-  // Make sure the function is the Array() function
-  __ LoadArrayFunction(r4);
-  __ cmp(r1, r4);
+  // Non-array cache: Check the cache state.
+  __ CompareRoot(r4, kPremonomorphicRootIndex);
+  __ b(eq, &initialize_non_array);
+  __ CompareRoot(r4, kUninitializedRootIndex);
   __ b(ne, &megamorphic);
+
+  // Non-array cache: Uninitialized -> premonomorphic. The sentinel is an
+  // immortal immovable object (null) so no write-barrier is needed.
+  __ add(r4, r2, Operand::PointerOffsetFromSmiKey(r3));
+  __ LoadRoot(ip, kPremonomorphicRootIndex);
+  __ str(ip, FieldMemOperand(r4, FixedArray::kHeaderSize));
   __ jmp(&done);
 
-  __ bind(&miss);
+  // Array cache: Check the cache state to see if we're in a monomorphic
+  // state where the state object is an AllocationSite object.
+  __ bind(&check_array);
+  __ ldr(r5, FieldMemOperand(r4, 0));
+  __ CompareRoot(r5, Heap::kAllocationSiteMapRootIndex);
+  __ b(eq, &done);
 
-  // A monomorphic miss (i.e, here the cache is not uninitialized) goes
-  // megamorphic.
-  __ CompareRoot(r4, Heap::kTheHoleValueRootIndex);
-  __ b(eq, &initialize);
-  // MegamorphicSentinel is an immortal immovable object (undefined) so no
-  // write-barrier is needed.
+  // Array cache: Uninitialized or premonomorphic -> monomorphic.
+  __ CompareRoot(r4, kUninitializedRootIndex);
+  __ b(eq, &initialize_array);
+  __ CompareRoot(r4, kPremonomorphicRootIndex);
+  __ b(eq, &initialize_array);
+
+  // Both caches: Monomorphic -> megamorphic. The sentinel is an
+  // immortal immovable object (undefined) so no write-barrier is needed.
   __ bind(&megamorphic);
   __ add(r4, r2, Operand::PointerOffsetFromSmiKey(r3));
-  __ LoadRoot(ip, Heap::kUndefinedValueRootIndex);
+  __ LoadRoot(ip, kMegamorphicRootIndex);
   __ str(ip, FieldMemOperand(r4, FixedArray::kHeaderSize));
   __ jmp(&done);
 
-  // An uninitialized cache is patched with the function or sentinel to
-  // indicate the ElementsKind if function is the Array constructor.
-  __ bind(&initialize);
-  // Make sure the function is the Array() function
-  __ LoadArrayFunction(r4);
-  __ cmp(r1, r4);
-  __ b(ne, &not_array_function);
-
-  // The target function is the Array constructor,
-  // Create an AllocationSite if we don't already have it, store it in the slot.
+  // Array cache: Uninitialized or premonomorphic -> monomorphic.
+  __ bind(&initialize_array);
   {
     FrameScope scope(masm, StackFrame::INTERNAL);
 
@@ -3081,8 +3091,8 @@ static void GenerateRecordCallTarget(MacroAssembler* masm) {
   }
   __ b(&done);
 
-  __ bind(&not_array_function);
-
+  // Non-array cache: Premonomorphic -> monomorphic.
+  __ bind(&initialize_non_array);
   __ add(r4, r2, Operand::PointerOffsetFromSmiKey(r3));
   __ add(r4, r4, Operand(FixedArray::kHeaderSize - kHeapObjectTag));
   __ str(r1, MemOperand(r4, 0));

diff --git a/src/ia32/code-stubs-ia32.cc b/src/ia32/code-stubs-ia32.cc
index 78824195df456e2787c6be0f12e76c77ec56e125..22709e41a0d50b3d75d8a53df77aafea373b6ad3 100644 (file)
--- a/src/ia32/code-stubs-ia32.cc
+++ b/src/ia32/code-stubs-ia32.cc
@@ -2330,7 +2330,7 @@ static void GenerateRecordCallTarget(MacroAssembler* masm) {
   // edx : slot in feedback vector (Smi)
   // edi : the function to call
   Isolate* isolate = masm->isolate();
-  Label initialize, done, miss, megamorphic, not_array_function;
+  Label check_array, initialize_array, initialize_non_array, megamorphic, done;
 
   // Load the cache state into ecx.
   __ mov(ecx, FieldOperand(ebx, edx, times_half_pointer_size,
@@ -2343,48 +2343,53 @@ static void GenerateRecordCallTarget(MacroAssembler* masm) {
   __ cmp(ecx, Immediate(TypeFeedbackInfo::MegamorphicSentinel(isolate)));
   __ j(equal, &done, Label::kFar);
 
-  // If we came here, we need to see if we are the array function.
-  // If we didn't have a matching function, and we didn't find the megamorph
-  // sentinel, then we have in the slot either some other function or an
-  // AllocationSite. Do a map check on the object in ecx.
-  Handle<Map> allocation_site_map =
-      masm->isolate()->factory()->allocation_site_map();
-  __ cmp(FieldOperand(ecx, 0), Immediate(allocation_site_map));
-  __ j(not_equal, &miss);
-
-  // Load the global or builtins object from the current context
+  // Load the global or builtins object from the current context and check
+  // if we're dealing with the Array function or not.
   __ LoadGlobalContext(ecx);
-  // Make sure the function is the Array() function
   __ cmp(edi, Operand(ecx,
                       Context::SlotOffset(Context::ARRAY_FUNCTION_INDEX)));
+  __ j(equal, &check_array);
+
+  // Non-array cache: Reload the cache state and check it.
+  __ mov(ecx, FieldOperand(ebx, edx, times_half_pointer_size,
+                           FixedArray::kHeaderSize));
+  __ cmp(ecx, Immediate(TypeFeedbackInfo::PremonomorphicSentinel(isolate)));
+  __ j(equal, &initialize_non_array);
+  __ cmp(ecx, Immediate(TypeFeedbackInfo::UninitializedSentinel(isolate)));
   __ j(not_equal, &megamorphic);
+
+  // Non-array cache: Uninitialized -> premonomorphic. The sentinel is an
+  // immortal immovable object (null) so no write-barrier is needed.
+  __ mov(FieldOperand(ebx, edx, times_half_pointer_size,
+                      FixedArray::kHeaderSize),
+         Immediate(TypeFeedbackInfo::PremonomorphicSentinel(isolate)));
   __ jmp(&done, Label::kFar);
 
-  __ bind(&miss);
+  // Array cache: Reload the cache state and check to see if we're in a
+  // monomorphic state where the state object is an AllocationSite object.
+  __ bind(&check_array);
+  __ mov(ecx, FieldOperand(ebx, edx, times_half_pointer_size,
+                           FixedArray::kHeaderSize));
+  Handle<Map> allocation_site_map = isolate->factory()->allocation_site_map();
+  __ cmp(FieldOperand(ecx, 0), Immediate(allocation_site_map));
+  __ j(equal, &done, Label::kFar);
 
-  // A monomorphic miss (i.e, here the cache is not uninitialized) goes
-  // megamorphic.
+  // Array cache: Uninitialized or premonomorphic -> monomorphic.
   __ cmp(ecx, Immediate(TypeFeedbackInfo::UninitializedSentinel(isolate)));
-  __ j(equal, &initialize);
-  // MegamorphicSentinel is an immortal immovable object (undefined) so no
-  // write-barrier is needed.
+  __ j(equal, &initialize_array);
+  __ cmp(ecx, Immediate(TypeFeedbackInfo::PremonomorphicSentinel(isolate)));
+  __ j(equal, &initialize_array);
+
+  // Both caches: Monomorphic -> megamorphic. The sentinel is an
+  // immortal immovable object (undefined) so no write-barrier is needed.
   __ bind(&megamorphic);
   __ mov(FieldOperand(ebx, edx, times_half_pointer_size,
                       FixedArray::kHeaderSize),
          Immediate(TypeFeedbackInfo::MegamorphicSentinel(isolate)));
   __ jmp(&done, Label::kFar);
 
-  // An uninitialized cache is patched with the function or sentinel to
-  // indicate the ElementsKind if function is the Array constructor.
-  __ bind(&initialize);
-  __ LoadGlobalContext(ecx);
-  // 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,
-  // Create an AllocationSite if we don't already have it, store it in the slot.
+  // Array cache: Uninitialized or premonomorphic -> monomorphic.
+  __ bind(&initialize_array);
   {
     FrameScope scope(masm, StackFrame::INTERNAL);
 
@@ -2406,11 +2411,11 @@ static void GenerateRecordCallTarget(MacroAssembler* masm) {
   }
   __ jmp(&done);
 
-  __ bind(&not_array_function);
+  // Non-array cache: Premonomorphic -> monomorphic.
+  __ bind(&initialize_non_array);
   __ mov(FieldOperand(ebx, edx, times_half_pointer_size,
                       FixedArray::kHeaderSize),
          edi);
-  // We won't need edx or ebx anymore, just save edi
   __ push(edi);
   __ push(ebx);
   __ push(edx);

diff --git a/src/objects-inl.h b/src/objects-inl.h
index 4f168066b3ee5efda3c33bc69d099d109baa1133..ffec178d42025c2d52eb8bfad7017816e1dbee59 100644 (file)
--- a/src/objects-inl.h
+++ b/src/objects-inl.h
@@ -6543,6 +6543,11 @@ Handle<Object> TypeFeedbackInfo::UninitializedSentinel(Isolate* isolate) {
 }
 
 
+Handle<Object> TypeFeedbackInfo::PremonomorphicSentinel(Isolate* isolate) {
+  return isolate->factory()->null_value();
+}
+
+
 Handle<Object> TypeFeedbackInfo::MegamorphicSentinel(Isolate* isolate) {
   return isolate->factory()->undefined_value();
 }

diff --git a/src/objects.h b/src/objects.h
index acd2c110064ddaf4f6e947993a3d4983acea91a9..05ab695de83de9a3fae63aeecdc88a15e40586c2 100644 (file)
--- a/src/objects.h
+++ b/src/objects.h
@@ -8174,6 +8174,9 @@ class TypeFeedbackInfo: public Struct {
   // The object that indicates an uninitialized cache.
   static inline Handle<Object> UninitializedSentinel(Isolate* isolate);
 
+  // The object that indicates a cache in pre-monomorphic state.
+  static inline Handle<Object> PremonomorphicSentinel(Isolate* isolate);
+
   // The object that indicates a megamorphic state.
   static inline Handle<Object> MegamorphicSentinel(Isolate* isolate);
 

diff --git a/src/runtime.cc b/src/runtime.cc
index 05392caefcc3cadcb11f026eb854a62d0ff1ef77..50621a997d0b64c03ad3cce486030d4ccbb6cf50 100644 (file)
--- a/src/runtime.cc
+++ b/src/runtime.cc
@@ -14774,6 +14774,7 @@ RUNTIME_FUNCTION(MaybeObject*, Runtime_ArrayConstructor) {
 
   Handle<AllocationSite> site;
   if (!type_info.is_null() &&
+      *type_info != isolate->heap()->null_value() &&
       *type_info != isolate->heap()->undefined_value()) {
     site = Handle<AllocationSite>::cast(type_info);
     ASSERT(!site->SitePointsToLiteral());

diff --git a/src/x64/code-stubs-x64.cc b/src/x64/code-stubs-x64.cc
index 8c5a430014de2658879369f53378c2dd251dac05..92af1f0455311c2caebcefbe4e475bda73ab303d 100644 (file)
--- a/src/x64/code-stubs-x64.cc
+++ b/src/x64/code-stubs-x64.cc
@@ -2169,8 +2169,7 @@ static void GenerateRecordCallTarget(MacroAssembler* masm) {
   // rdx : slot in feedback vector (Smi)
   // rdi : the function to call
   Isolate* isolate = masm->isolate();
-  Label initialize, done, miss, megamorphic, not_array_function,
-      done_no_smi_convert;
+  Label check_array, initialize_array, initialize_non_array, megamorphic, done;
 
   // Load the cache state into rcx.
   __ SmiToInteger32(rdx, rdx);
@@ -2184,44 +2183,49 @@ static void GenerateRecordCallTarget(MacroAssembler* masm) {
   __ Cmp(rcx, TypeFeedbackInfo::MegamorphicSentinel(isolate));
   __ j(equal, &done);
 
-  // If we came here, we need to see if we are the array function.
-  // If we didn't have a matching function, and we didn't find the megamorph
-  // sentinel, then we have in the slot either some other function or an
-  // AllocationSite. Do a map check on the object in rcx.
-  Handle<Map> allocation_site_map =
-      masm->isolate()->factory()->allocation_site_map();
-  __ Cmp(FieldOperand(rcx, 0), allocation_site_map);
-  __ j(not_equal, &miss);
-
-  // Make sure the function is the Array() function
+  // Check if we're dealing with the Array function or not.
   __ LoadArrayFunction(rcx);
   __ cmpq(rdi, rcx);
+  __ j(equal, &check_array);
+
+  // Non-array cache: Reload the cache state and check it.
+  __ movp(rcx, FieldOperand(rbx, rdx, times_pointer_size,
+                            FixedArray::kHeaderSize));
+  __ Cmp(rcx, TypeFeedbackInfo::PremonomorphicSentinel(isolate));
+  __ j(equal, &initialize_non_array);
+  __ Cmp(rcx, TypeFeedbackInfo::UninitializedSentinel(isolate));
   __ j(not_equal, &megamorphic);
-  __ jmp(&done);
 
-  __ bind(&miss);
+  // Non-array cache: Uninitialized -> premonomorphic. The sentinel is an
+  // immortal immovable object (null) so no write-barrier is needed.
+  __ Move(FieldOperand(rbx, rdx, times_pointer_size, FixedArray::kHeaderSize),
+          TypeFeedbackInfo::PremonomorphicSentinel(isolate));
+  __ jmp(&done, Label::kFar);
 
-  // A monomorphic miss (i.e, here the cache is not uninitialized) goes
-  // megamorphic.
+  // Array cache: Reload the cache state and check to see if we're in a
+  // monomorphic state where the state object is an AllocationSite object.
+  __ bind(&check_array);
+  __ movp(rcx, FieldOperand(rbx, rdx, times_pointer_size,
+                            FixedArray::kHeaderSize));
+  Handle<Map> allocation_site_map = isolate->factory()->allocation_site_map();
+  __ Cmp(FieldOperand(rcx, 0), allocation_site_map);
+  __ j(equal, &done);
+
+  // Array cache: Uninitialized or premonomorphic -> monomorphic.
   __ Cmp(rcx, TypeFeedbackInfo::UninitializedSentinel(isolate));
-  __ j(equal, &initialize);
-  // MegamorphicSentinel is an immortal immovable object (undefined) so no
-  // write-barrier is needed.
+  __ j(equal, &initialize_array);
+  __ Cmp(rcx, TypeFeedbackInfo::PremonomorphicSentinel(isolate));
+  __ j(equal, &initialize_array);
+
+  // Both caches: Monomorphic -> megamorphic. The sentinel is an
+  // immortal immovable object (undefined) so no write-barrier is needed.
   __ bind(&megamorphic);
   __ Move(FieldOperand(rbx, rdx, times_pointer_size, FixedArray::kHeaderSize),
           TypeFeedbackInfo::MegamorphicSentinel(isolate));
   __ jmp(&done);
 
-  // An uninitialized cache is patched with the function or sentinel to
-  // indicate the ElementsKind if function is the Array constructor.
-  __ bind(&initialize);
-  // Make sure the function is the Array() function
-  __ LoadArrayFunction(rcx);
-  __ cmpq(rdi, rcx);
-  __ j(not_equal, &not_array_function);
-
-  // The target function is the Array constructor,
-  // Create an AllocationSite if we don't already have it, store it in the slot.
+  // Array cache: Uninitialized or premonomorphic -> monomorphic.
+  __ bind(&initialize_array);
   {
     FrameScope scope(masm, StackFrame::INTERNAL);
 
@@ -2242,13 +2246,13 @@ static void GenerateRecordCallTarget(MacroAssembler* masm) {
     __ pop(rax);
     __ SmiToInteger32(rax, rax);
   }
+  Label done_no_smi_convert;
   __ jmp(&done_no_smi_convert);
 
-  __ bind(&not_array_function);
+  // Non-array cache: Premonomorphic -> monomorphic.
+  __ bind(&initialize_non_array);
   __ movp(FieldOperand(rbx, rdx, times_pointer_size, FixedArray::kHeaderSize),
           rdi);
-
-  // We won't need rdx or rbx anymore, just save rdi
   __ push(rdi);
   __ push(rbx);
   __ push(rdx);

diff --git a/test/cctest/test-heap.cc b/test/cctest/test-heap.cc
index ff9e51a621ab7f4c634d4de79722134265c8eabf..2cc9ecac3990ce440e18b1946f12ee22b855bcb6 100644 (file)
--- a/test/cctest/test-heap.cc
+++ b/test/cctest/test-heap.cc
@@ -2848,7 +2848,9 @@ TEST(IncrementalMarkingClearsTypeFeedbackInfo) {
   // originating from two different native contexts.
   CcTest::global()->Set(v8_str("fun1"), fun1);
   CcTest::global()->Set(v8_str("fun2"), fun2);
-  CompileRun("function f(a, b) { a(); b(); } f(fun1, fun2);");
+  CompileRun("function f(a, b) { a(); b(); }"
+             "f(fun1, fun2);"  // Run twice to skip premonomorphic state.
+             "f(fun1, fun2)");
 
   Handle<JSFunction> f =
       v8::Utils::OpenHandle(