Pretenure call new support.

src/arm/code-stubs-arm.cc

Index: src/arm/code-stubs-arm.cc
diff --git a/src/arm/code-stubs-arm.cc b/src/arm/code-stubs-arm.cc
index 748b5313850a7606ad6e4d97127dd46c58af8d1e..cad641738c7a682310eb4b2a752ea35cf98dcdf5 100644
--- a/src/arm/code-stubs-arm.cc
+++ b/src/arm/code-stubs-arm.cc
@@ -2946,19 +2946,21 @@ static void GenerateRecordCallTarget(MacroAssembler* masm) {
   __ cmp(r4, r1);
   __ 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);
+  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.
+    __ ldr(r5, FieldMemOperand(r4, 0));
+    __ CompareRoot(r5, Heap::kAllocationSiteMapRootIndex);
+    __ b(ne, &miss);
 
-  // Make sure the function is the Array() function
-  __ LoadGlobalFunction(Context::ARRAY_FUNCTION_INDEX, r4);
-  __ cmp(r1, r4);
-  __ b(ne, &megamorphic);
-  __ jmp(&done);
+    // Make sure the function is the Array() function
+    __ LoadGlobalFunction(Context::ARRAY_FUNCTION_INDEX, r4);
+    __ cmp(r1, r4);
+    __ b(ne, &megamorphic);
+    __ jmp(&done);
+  }
 
   __ bind(&miss);
 
@@ -2974,32 +2976,35 @@ static void GenerateRecordCallTarget(MacroAssembler* masm) {
   __ 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.
+  // An uninitialized cache is patched with the function
   __ bind(&initialize);
-  // Make sure the function is the Array() function
-  __ LoadGlobalFunction(Context::ARRAY_FUNCTION_INDEX, 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.
-  {
-    FrameAndConstantPoolScope scope(masm, StackFrame::INTERNAL);
+  if (!FLAG_pretenuring_call_new) {
+    // Make sure the function is the Array() function
+    __ LoadGlobalFunction(Context::ARRAY_FUNCTION_INDEX, r4);
+    __ cmp(r1, r4);
+    __ b(ne, &not_array_function);
 
-    // Arguments register must be smi-tagged to call out.
-    __ SmiTag(r0);
-    __ Push(r3, r2, r1, r0);
+    // The target function is the Array constructor,
+    // Create an AllocationSite if we don't already have it, store it in the
+    // slot.
+    {
+      FrameAndConstantPoolScope scope(masm, StackFrame::INTERNAL);
 
-    CreateAllocationSiteStub create_stub;
-    __ CallStub(&create_stub);
+      // Arguments register must be smi-tagged to call out.
+      __ SmiTag(r0);
+      __ Push(r3, r2, r1, r0);
 
-    __ Pop(r3, r2, r1, r0);
-    __ SmiUntag(r0);
-  }
-  __ b(&done);
+      CreateAllocationSiteStub create_stub;
+      __ CallStub(&create_stub);
 
-  __ bind(&not_array_function);
+      __ Pop(r3, r2, r1, r0);
+      __ SmiUntag(r0);
+    }
+    __ b(&done);
+
+    __ bind(&not_array_function);
+  }
 
   __ add(r4, r2, Operand::PointerOffsetFromSmiKey(r3));
   __ add(r4, r4, Operand(FixedArray::kHeaderSize - kHeapObjectTag));
@@ -3138,17 +3143,25 @@ void CallConstructStub::Generate(MacroAssembler* masm) {
   __ b(ne, &slow);
 
   if (RecordCallTarget()) {
-    Label feedback_register_initialized;
     GenerateRecordCallTarget(masm);
 
-    // Put the AllocationSite from the feedback vector into r2, or undefined.
     __ add(r5, r2, Operand::PointerOffsetFromSmiKey(r3));
-    __ ldr(r2, FieldMemOperand(r5, FixedArray::kHeaderSize));
-    __ ldr(r5, FieldMemOperand(r2, AllocationSite::kMapOffset));
-    __ CompareRoot(r5, Heap::kAllocationSiteMapRootIndex);
-    __ b(eq, &feedback_register_initialized);
-    __ LoadRoot(r2, Heap::kUndefinedValueRootIndex);
-    __ bind(&feedback_register_initialized);
+    if (FLAG_pretenuring_call_new) {
+      // Put the AllocationSite from the feedback vector into r2.
+      // By adding kPointerSize we encode that we know the AllocationSite
+      // entry is at the feedback vector slot given by r3 + 1.
+      __ ldr(r2, FieldMemOperand(r5, FixedArray::kHeaderSize + kPointerSize));
+    } else {
+      Label feedback_register_initialized;
+      // Put the AllocationSite from the feedback vector into r2, or undefined.
+      __ ldr(r2, FieldMemOperand(r5, FixedArray::kHeaderSize));
+      __ ldr(r5, FieldMemOperand(r2, AllocationSite::kMapOffset));
+      __ CompareRoot(r5, Heap::kAllocationSiteMapRootIndex);
+      __ b(eq, &feedback_register_initialized);
+      __ LoadRoot(r2, Heap::kUndefinedValueRootIndex);
+      __ bind(&feedback_register_initialized);
+    }
+
     __ AssertUndefinedOrAllocationSite(r2, r5);
   }