Pretenure call new support.

src/ia32/code-stubs-ia32.cc

Index: src/ia32/code-stubs-ia32.cc
diff --git a/src/ia32/code-stubs-ia32.cc b/src/ia32/code-stubs-ia32.cc
index 9ac0551ef898c068dc7716d4b9319f23f6a96fe6..fa67502ad0de1123811b5c597aa0274d2d31e9cd 100644
--- a/src/ia32/code-stubs-ia32.cc
+++ b/src/ia32/code-stubs-ia32.cc
@@ -2278,20 +2278,22 @@ 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);
-
-  // Make sure the function is the Array() function
-  __ LoadGlobalFunction(Context::ARRAY_FUNCTION_INDEX, ecx);
-  __ cmp(edi, ecx);
-  __ j(not_equal, &megamorphic);
-  __ jmp(&done, Label::kFar);
+  if (!FLAG_pretenuring_call_new) {
+    // 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);
+
+    // Make sure the function is the Array() function
+    __ LoadGlobalFunction(Context::ARRAY_FUNCTION_INDEX, ecx);
+    __ cmp(edi, ecx);
+    __ j(not_equal, &megamorphic);
+    __ jmp(&done, Label::kFar);
+  }
 
   __ bind(&miss);
 
@@ -2310,35 +2312,39 @@ static void GenerateRecordCallTarget(MacroAssembler* masm) {
   // 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
-  __ LoadGlobalFunction(Context::ARRAY_FUNCTION_INDEX, ecx);
-  __ cmp(edi, ecx);
-  __ j(not_equal, &not_array_function);
+  if (!FLAG_pretenuring_call_new) {
+    // Make sure the function is the Array() function
+    __ LoadGlobalFunction(Context::ARRAY_FUNCTION_INDEX, ecx);
+    __ cmp(edi, ecx);
+    __ 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.
+    {
+      FrameScope scope(masm, StackFrame::INTERNAL);
 
-  // The target function is the Array constructor,
-  // Create an AllocationSite if we don't already have it, store it in the slot.
-  {
-    FrameScope scope(masm, StackFrame::INTERNAL);
+      // Arguments register must be smi-tagged to call out.
+      __ SmiTag(eax);
+      __ push(eax);
+      __ push(edi);
+      __ push(edx);
+      __ push(ebx);
 
-    // Arguments register must be smi-tagged to call out.
-    __ SmiTag(eax);
-    __ push(eax);
-    __ push(edi);
-    __ push(edx);
-    __ push(ebx);
+      CreateAllocationSiteStub create_stub;
+      __ CallStub(&create_stub);
 
-    CreateAllocationSiteStub create_stub;
-    __ CallStub(&create_stub);
+      __ pop(ebx);
+      __ pop(edx);
+      __ pop(edi);
+      __ pop(eax);
+      __ SmiUntag(eax);
+    }
+    __ jmp(&done);
 
-    __ pop(ebx);
-    __ pop(edx);
-    __ pop(edi);
-    __ pop(eax);
-    __ SmiUntag(eax);
+    __ bind(&not_array_function);
   }
-  __ jmp(&done);
 
-  __ bind(&not_array_function);
   __ mov(FieldOperand(ebx, edx, times_half_pointer_size,
                       FixedArray::kHeaderSize),
          edi);
@@ -2481,18 +2487,27 @@ void CallConstructStub::Generate(MacroAssembler* masm) {
   __ j(not_equal, &slow);
 
   if (RecordCallTarget()) {
-    Label feedback_register_initialized;
     GenerateRecordCallTarget(masm);
 
-    // Put the AllocationSite from the feedback vector into ebx, or undefined.
-    __ mov(ebx, FieldOperand(ebx, edx, times_half_pointer_size,
-                             FixedArray::kHeaderSize));
-    Handle<Map> allocation_site_map =
-        masm->isolate()->factory()->allocation_site_map();
-    __ cmp(FieldOperand(ebx, 0), Immediate(allocation_site_map));
-    __ j(equal, &feedback_register_initialized);
-    __ mov(ebx, masm->isolate()->factory()->undefined_value());
-    __ bind(&feedback_register_initialized);
+    if (FLAG_pretenuring_call_new) {
+      // Put the AllocationSite from the feedback vector into ebx.
+      // By adding kPointerSize we encode that we know the AllocationSite
+      // entry is at the feedback vector slot given by edx + 1.
+      __ mov(ebx, FieldOperand(ebx, edx, times_half_pointer_size,
+                               FixedArray::kHeaderSize + kPointerSize));
+    } else {
+      Label feedback_register_initialized;
+      // Put the AllocationSite from the feedback vector into ebx, or undefined.
+      __ mov(ebx, FieldOperand(ebx, edx, times_half_pointer_size,
+                               FixedArray::kHeaderSize));
+      Handle<Map> allocation_site_map =
+          masm->isolate()->factory()->allocation_site_map();
+      __ cmp(FieldOperand(ebx, 0), Immediate(allocation_site_map));
+      __ j(equal, &feedback_register_initialized);
+      __ mov(ebx, masm->isolate()->factory()->undefined_value());
+      __ bind(&feedback_register_initialized);
+    }
+
     __ AssertUndefinedOrAllocationSite(ebx);
   }