PPC: [es6] Better support for built-ins subclassing.

src/ppc/builtins-ppc.cc

 // Copyright 2014 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.
 
 #if V8_TARGET_ARCH_PPC
 
 #include "src/codegen.h"
 #include "src/debug/debug.h"
 #include "src/deoptimizer.h"
 #include "src/full-codegen/full-codegen.h"
@@ skipping 204 matching lines @@
     __ TailCallRuntime(Runtime::kSymbolDescriptiveString, 1, 1);
   }
 }
 
 
 // static
 void Builtins::Generate_StringConstructor_ConstructStub(MacroAssembler* masm) {
   // ----------- S t a t e -------------
   //  -- r3                     : number of arguments
   //  -- r4                     : constructor function
+  //  -- r6                     : original constructor
   //  -- lr                     : return address
   //  -- sp[(argc - n - 1) * 4] : arg[n] (zero based)
   //  -- sp[argc * 4]           : receiver
   // -----------------------------------
 
-  // 1. Load the first argument into r3 and get rid of the rest (including the
+  // 1. Load the first argument into r5 and get rid of the rest (including the
   // receiver).
   {
     Label no_arguments, done;
     __ cmpi(r3, Operand::Zero());
     __ beq(&no_arguments);
     __ subi(r3, r3, Operand(1));
-    __ ShiftLeftImm(r3, r3, Operand(kPointerSizeLog2));
-    __ LoadPUX(r3, MemOperand(sp, r3));
+    __ ShiftLeftImm(r5, r3, Operand(kPointerSizeLog2));
+    __ LoadPUX(r5, MemOperand(sp, r5));
     __ Drop(2);
     __ b(&done);
     __ bind(&no_arguments);
-    __ LoadRoot(r3, Heap::kempty_stringRootIndex);
+    __ LoadRoot(r5, Heap::kempty_stringRootIndex);
     __ Drop(1);
     __ bind(&done);
   }
 
-  // 2. Make sure r3 is a string.
+  // 2. Make sure r5 is a string.
   {
     Label convert, done_convert;
-    __ JumpIfSmi(r3, &convert);
-    __ CompareObjectType(r3, r5, r5, FIRST_NONSTRING_TYPE);
+    __ JumpIfSmi(r5, &convert);
+    __ CompareObjectType(r5, r7, r7, FIRST_NONSTRING_TYPE);
     __ blt(&done_convert);
     __ bind(&convert);
     {
       FrameAndConstantPoolScope scope(masm, StackFrame::INTERNAL);
       ToStringStub stub(masm->isolate());
-      __ push(r4);
+      __ Push(r4, r6);
+      __ mr(r3, r5);
       __ CallStub(&stub);
-      __ pop(r4);
+      __ mr(r5, r3);
+      __ Pop(r4, r6);
     }
     __ bind(&done_convert);
   }
 
   // 3. Allocate a JSValue wrapper for the string.
   {
     // ----------- S t a t e -------------
-    //  -- r3 : the first argument
+    //  -- r5 : the first argument
     //  -- r4 : constructor function
+    //  -- r6 : original constructor
     //  -- lr : return address
     // -----------------------------------
 
-    Label allocate, done_allocate;
-    __ mr(r5, r3);
+    Label allocate, done_allocate, rt_call;
+
+    // Fall back to runtime if the original constructor and function differ.
+    __ cmp(r4, r6);
+    __ bne(&rt_call);
+
     __ Allocate(JSValue::kSize, r3, r6, r7, &allocate, TAG_OBJECT);
     __ bind(&done_allocate);
 
     // Initialize the JSValue in r3.
     __ LoadGlobalFunctionInitialMap(r4, r6, r7);
     __ StoreP(r6, FieldMemOperand(r3, HeapObject::kMapOffset), r0);
     __ LoadRoot(r6, Heap::kEmptyFixedArrayRootIndex);
     __ StoreP(r6, FieldMemOperand(r3, JSObject::kPropertiesOffset), r0);
     __ StoreP(r6, FieldMemOperand(r3, JSObject::kElementsOffset), r0);
     __ StoreP(r5, FieldMemOperand(r3, JSValue::kValueOffset), r0);
     STATIC_ASSERT(JSValue::kSize == 4 * kPointerSize);
     __ Ret();
 
     // Fallback to the runtime to allocate in new space.
     __ bind(&allocate);
     {
       FrameAndConstantPoolScope scope(masm, StackFrame::INTERNAL);
       __ LoadSmiLiteral(r6, Smi::FromInt(JSValue::kSize));
       __ Push(r4, r5, r6);
       __ CallRuntime(Runtime::kAllocateInNewSpace, 1);
       __ Pop(r4, r5);
     }
     __ b(&done_allocate);
+
+    // Fallback to the runtime to create new object.
+    __ bind(&rt_call);
+    {
+      FrameAndConstantPoolScope scope(masm, StackFrame::INTERNAL);
+      __ Push(r4, r5, r4, r6);  // constructor function, original constructor
+      __ CallRuntime(Runtime::kNewObject, 2);
+      __ Pop(r4, r5);
+    }
+    __ StoreP(r5, FieldMemOperand(r3, JSValue::kValueOffset), r0);
+    __ Ret();
   }
 }
 
 
 static void CallRuntimePassFunction(MacroAssembler* masm,
                                     Runtime::FunctionId function_id) {
   FrameAndConstantPoolScope scope(masm, StackFrame::INTERNAL);
   // Push a copy of the function onto the stack.
   // Push function as parameter to the runtime call.
   __ Push(r4, r4);
@@ skipping 195 matching lines @@
 
       // Reload the original constructor and fall-through.
       __ bind(&rt_call_reload_new_target);
       __ LoadP(r6, MemOperand(sp, 0 * kPointerSize));
     }
 
     // Allocate the new receiver object using the runtime call.
     // r4: constructor function
     // r6: original constructor
     __ bind(&rt_call);
-    __ Push(r4, r6);
+    __ Push(r4, r6);  // constructor function, original constructor
     __ CallRuntime(Runtime::kNewObject, 2);
     __ mr(r7, r3);
 
     // Receiver for constructor call allocated.
     // r7: JSObject
     __ bind(&allocated);
 
     // Restore the parameters.
     __ Pop(r4, ip);
 
@@ skipping 1422 matching lines @@
     __ bkpt(0);
   }
 }
 
 
 #undef __
 }  // namespace internal
 }  // namespace v8
 
 #endif  // V8_TARGET_ARCH_PPC