Cleanup Generate_JSConstructStubHelper a bit.

src/arm/builtins-arm.cc

 // Copyright 2012 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "src/v8.h"
 
 #if V8_TARGET_ARCH_ARM
 
 #include "src/codegen.h"
 #include "src/debug.h"
@@ skipping 293 matching lines @@
   __ b(hs, &ok);
 
   CallRuntimePassFunction(masm, Runtime::kTryInstallOptimizedCode);
   GenerateTailCallToReturnedCode(masm);
 
   __ bind(&ok);
   GenerateTailCallToSharedCode(masm);
 }
 
 
-static void Generate_Runtime_NewObject(MacroAssembler* masm,
-                                       bool create_memento,
-                                       Register original_constructor,
-                                       Label* count_incremented,
-                                       Label* allocated) {
-  if (create_memento) {
-    // Get the cell or allocation site.
-    __ ldr(r2, MemOperand(sp, 3 * kPointerSize));
-    __ push(r2);
-  }
-
-  __ push(r1);                    // argument for Runtime_NewObject
-  __ push(original_constructor);  // original constructor
-  if (create_memento) {
-    __ CallRuntime(Runtime::kNewObjectWithAllocationSite, 3);
-  } else {
-    __ CallRuntime(Runtime::kNewObject, 2);
-  }
-  __ mov(r4, r0);
-
-  // Runtime_NewObjectWithAllocationSite increments allocation count.
-  // Skip the increment.
-  if (create_memento) {
-    __ jmp(count_incremented);
-  } else {
-    __ jmp(allocated);
-  }
-}
-
-
 static void Generate_JSConstructStubHelper(MacroAssembler* masm,
                                            bool is_api_function,
                                            bool create_memento) {
   // ----------- S t a t e -------------
   //  -- r0     : number of arguments
   //  -- r1     : constructor function
   //  -- r2     : allocation site or undefined
   //  -- r3     : original constructor
   //  -- lr     : return address
   //  -- sp[...]: constructor arguments
@@ skipping 12 matching lines @@
       __ AssertUndefinedOrAllocationSite(r2, r4);
       __ push(r2);
     }
 
     // Preserve the incoming parameters on the stack.
     __ SmiTag(r0);
     __ push(r0);
     __ push(r1);
     __ push(r3);
 
-    Label rt_call, allocated, normal_new, count_incremented;
-    __ cmp(r1, r3);
-    __ b(eq, &normal_new);
-
-    // Original constructor and function are different.
-    Generate_Runtime_NewObject(masm, create_memento, r3, &count_incremented,
-                               &allocated);
-    __ bind(&normal_new);
-
     // Try to allocate the object without transitioning into C code. If any of
     // the preconditions is not met, the code bails out to the runtime call.
+    Label rt_call, allocated;
     if (FLAG_inline_new) {
       ExternalReference debug_step_in_fp =
           ExternalReference::debug_step_in_fp_address(isolate);
       __ mov(r2, Operand(debug_step_in_fp));
       __ ldr(r2, MemOperand(r2));
       __ tst(r2, r2);
       __ b(ne, &rt_call);
 
+      // Fall back to runtime if the original constructor and function differ.
+      __ cmp(r1, r3);
+      __ b(ne, &rt_call);
+
       // Load the initial map and verify that it is in fact a map.
       // r1: constructor function
       __ ldr(r2, FieldMemOperand(r1, JSFunction::kPrototypeOrInitialMapOffset));
       __ JumpIfSmi(r2, &rt_call);
-      __ CompareObjectType(r2, r3, r4, MAP_TYPE);
+      __ CompareObjectType(r2, r5, r4, MAP_TYPE);
       __ b(ne, &rt_call);
 
       // Check that the constructor is not constructing a JSFunction (see
       // comments in Runtime_NewObject in runtime.cc). In which case the
       // initial map's instance type would be JS_FUNCTION_TYPE.
       // r1: constructor function
       // r2: initial map
-      __ CompareInstanceType(r2, r3, JS_FUNCTION_TYPE);
+      __ CompareInstanceType(r2, r5, JS_FUNCTION_TYPE);
       __ b(eq, &rt_call);
 
       if (!is_api_function) {
         Label allocate;
         MemOperand bit_field3 = FieldMemOperand(r2, Map::kBitField3Offset);
         // Check if slack tracking is enabled.
         __ ldr(r4, bit_field3);
         __ DecodeField<Map::Counter>(r3, r4);
         __ cmp(r3, Operand(Map::kSlackTrackingCounterEnd));
         __ b(lt, &allocate);
@@ skipping 10 matching lines @@
 
         __ pop(r2);
         __ pop(r1);
 
         __ bind(&allocate);
       }
 
       // Now allocate the JSObject on the heap.
       // r1: constructor function
       // r2: initial map
+      Label rt_call_reload_new_target;
       __ ldrb(r3, FieldMemOperand(r2, Map::kInstanceSizeOffset));
       if (create_memento) {
         __ add(r3, r3, Operand(AllocationMemento::kSize / kPointerSize));
       }
 
-      __ Allocate(r3, r4, r5, r6, &rt_call, SIZE_IN_WORDS);
+      __ Allocate(r3, r4, r5, r6, &rt_call_reload_new_target, SIZE_IN_WORDS);
 
       // Allocated the JSObject, now initialize the fields. Map is set to
       // initial map and properties and elements are set to empty fixed array.
       // r1: constructor function
       // r2: initial map
       // r3: object size (including memento if create_memento)
       // r4: JSObject (not tagged)
       __ LoadRoot(r6, Heap::kEmptyFixedArrayRootIndex);
       __ mov(r5, r4);
       DCHECK_EQ(0 * kPointerSize, JSObject::kMapOffset);
@@ skipping 63 matching lines @@
         __ InitializeFieldsWithFiller(r5, r0, r6);
       }
 
       // Add the object tag to make the JSObject real, so that we can continue
       // and jump into the continuation code at any time from now on.
       __ add(r4, r4, Operand(kHeapObjectTag));
 
       // Continue with JSObject being successfully allocated
       // r4: JSObject
       __ jmp(&allocated);
+
+      // Reload the original constructor and fall-through.
+      __ bind(&rt_call_reload_new_target);
+      __ ldr(r3, MemOperand(sp, 0 * kPointerSize));
     }
 
     // Allocate the new receiver object using the runtime call.
     // r1: constructor function
+    // r3: original constructor
     __ bind(&rt_call);
-    Generate_Runtime_NewObject(masm, create_memento, r1, &count_incremented,
-                               &allocated);
+    if (create_memento) {
+      // Get the cell or allocation site.
+      __ ldr(r2, MemOperand(sp, 3 * kPointerSize));
+      __ push(r2);  // argument 1: allocation site
+    }
+
+    __ push(r1);  // argument 2/1: constructor function
+    __ push(r3);  // argument 3/2: original constructor
+    if (create_memento) {
+      __ CallRuntime(Runtime::kNewObjectWithAllocationSite, 3);
+    } else {
+      __ CallRuntime(Runtime::kNewObject, 2);
+    }
+    __ mov(r4, r0);
+
+    // Runtime_NewObjectWithAllocationSite increments allocation count.
+    // Skip the increment.
+    Label count_incremented;
+    if (create_memento) {
+      __ jmp(&count_incremented);
+    }
 
     // Receiver for constructor call allocated.
     // r4: JSObject
     __ bind(&allocated);
 
     if (create_memento) {
       __ ldr(r2, MemOperand(sp, 3 * kPointerSize));
       __ LoadRoot(r5, Heap::kUndefinedValueRootIndex);
       __ cmp(r2, r5);
       __ b(eq, &count_incremented);
@@ skipping 68 matching lines @@
     // sp[2]: number of arguments (smi-tagged)
     __ ldr(cp, MemOperand(fp, StandardFrameConstants::kContextOffset));
 
     // If the result is an object (in the ECMA sense), we should get rid
     // of the receiver and use the result; see ECMA-262 section 13.2.2-7
     // on page 74.
     Label use_receiver, exit;
 
     // If the result is a smi, it is *not* an object in the ECMA sense.
     // r0: result
-    // sp[0]: receiver (newly allocated object)
-    // sp[1]: new.target (if used)
-    // sp[1/2]: number of arguments (smi-tagged)
+    // sp[0]: receiver
+    // sp[1]: new.target
+    // sp[2]: number of arguments (smi-tagged)
     __ JumpIfSmi(r0, &use_receiver);
 
     // If the type of the result (stored in its map) is less than
     // FIRST_SPEC_OBJECT_TYPE, it is not an object in the ECMA sense.
     __ CompareObjectType(r0, r1, r3, FIRST_SPEC_OBJECT_TYPE);
     __ b(ge, &exit);
 
     // Throw away the result of the constructor invocation and use the
     // on-stack receiver as the result.
     __ bind(&use_receiver);
@@ skipping 1104 matching lines @@
   }
 }
 
 
 #undef __
 
 }  // namespace internal
 }  // namespace v8
 
 #endif  // V8_TARGET_ARCH_ARM