MIPS: new classes: implement default constructors.

src/mips/full-codegen-mips.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_MIPS
 
 // Note on Mips implementation:
 //
@@ skipping 3023 matching lines @@
   // a1: the start position of the scope the calls resides in.
   __ li(a1, Operand(Smi::FromInt(scope()->start_position())));
 
   // Do the runtime call.
   __ Push(t3);
   __ Push(t2, t1, t0, a1);
   __ CallRuntime(Runtime::kResolvePossiblyDirectEval, 6);
 }
 
 
-void FullCodeGenerator::EmitLoadSuperConstructor(SuperReference* super_ref) {
-  DCHECK(super_ref != NULL);
+void FullCodeGenerator::EmitLoadSuperConstructor() {
   __ lw(a0, MemOperand(fp, JavaScriptFrameConstants::kFunctionOffset));
   __ Push(a0);
   __ CallRuntime(Runtime::kGetPrototype, 1);
 }
 
 
 void FullCodeGenerator::VisitCall(Call* expr) {
 #ifdef DEBUG
   // We want to verify that RecordJSReturnSite gets called on all paths
   // through this function.  Avoid early returns.
@@ skipping 103 matching lines @@
       if (is_named_call) {
         EmitCallWithLoadIC(expr);
       } else {
         EmitKeyedCallWithLoadIC(expr, property->key());
       }
     }
   } else if (call_type == Call::SUPER_CALL) {
     if (FLAG_experimental_classes) {
       EmitSuperConstructorCall(expr);
     } else {
+      EmitLoadSuperConstructor();
+      __ Push(result_register());
       SuperReference* super_ref = callee->AsSuperReference();
-      EmitLoadSuperConstructor(super_ref);
-      __ Push(result_register());
       VisitForStackValue(super_ref->this_var());
       EmitCall(expr, CallICState::METHOD);
     }
   } else {
     DCHECK(call_type == Call::OTHER_CALL);
     // Call to an arbitrary expression not handled specially above.
     { PreservePositionScope scope(masm()->positions_recorder());
       VisitForStackValue(callee);
     }
     __ LoadRoot(a1, Heap::kUndefinedValueRootIndex);
@@ skipping 52 matching lines @@
   context()->Plug(v0);
 }
 
 
 void FullCodeGenerator::EmitSuperConstructorCall(Call* expr) {
   Comment cmnt(masm_, "[ SuperConstructorCall");
   Variable* new_target_var = scope()->DeclarationScope()->new_target_var();
   GetVar(result_register(), new_target_var);
   __ Push(result_register());
 
-  SuperReference* super_ref = expr->expression()->AsSuperReference();
-  EmitLoadSuperConstructor(super_ref);
+  EmitLoadSuperConstructor();
   __ push(result_register());
 
+  SuperReference* super_ref = expr->expression()->AsSuperReference();
   Variable* this_var = super_ref->this_var()->var();
 
   GetVar(a0, this_var);
   __ LoadRoot(at, Heap::kTheHoleValueRootIndex);
   Label uninitialized_this;
   __ Branch(&uninitialized_this, eq, a0, Operand(at));
   __ li(a0, Operand(this_var->name()));
   __ Push(a0);
   __ CallRuntime(Runtime::kThrowReferenceError, 1);
   __ bind(&uninitialized_this);
@@ skipping 910 matching lines @@
 
   __ bind(&runtime);
   __ push(v0);
   __ CallRuntime(Runtime::kCall, args->length());
   __ bind(&done);
 
   context()->Plug(v0);
 }
 
 
+void FullCodeGenerator::EmitDefaultConstructorCallSuper(CallRuntime* expr) {
+  Variable* new_target_var = scope()->DeclarationScope()->new_target_var();
+  GetVar(result_register(), new_target_var);
+  __ Push(result_register());
+
+  EmitLoadSuperConstructor();
+  __ Push(result_register());
+
+  // Check if the calling frame is an arguments adaptor frame.
+  Label adaptor_frame, args_set_up, runtime;
+  __ lw(a2, MemOperand(fp, StandardFrameConstants::kCallerFPOffset));
+  __ lw(a3, MemOperand(a2, StandardFrameConstants::kContextOffset));
+  __ Branch(&adaptor_frame, eq, a3,
+            Operand(Smi::FromInt(StackFrame::ARGUMENTS_ADAPTOR)));
+  // default constructor has no arguments, so no adaptor frame means no args.
+  __ mov(a0, zero_reg);
+  __ Branch(&args_set_up);
+
+  // Copy arguments from adaptor frame.
+  {
+    __ bind(&adaptor_frame);
+    __ lw(a1, MemOperand(a2, ArgumentsAdaptorFrameConstants::kLengthOffset));
+    __ SmiUntag(a1, a1);
+
+    // Subtract 1 from arguments count, for new.target.
+    __ Addu(a1, a1, Operand(-1));
+    __ mov(a0, a1);
+
+    // Get arguments pointer in a2.
+    __ sll(at, a1, kPointerSizeLog2);
+    __ addu(a2, a2, at);
+    __ Addu(a2, a2, Operand(StandardFrameConstants::kCallerSPOffset));
+    Label loop;
+    __ bind(&loop);
+    // Pre-decrement a2 with kPointerSize on each iteration.
+    // Pre-decrement in order to skip receiver.
+    __ Addu(a2, a2, Operand(-kPointerSize));
+    __ lw(a3, MemOperand(a2));
+    __ Push(a3);
+    __ Addu(a1, a1, Operand(-1));
+    __ Branch(&loop, ne, a1, Operand(zero_reg));
+  }
+
+  __ bind(&args_set_up);
+  __ sll(at, a0, kPointerSizeLog2);
+  __ Addu(at, at, Operand(sp));
+  __ lw(a1, MemOperand(at, 0));
+
+  CallConstructStub stub(isolate(), SUPER_CONSTRUCTOR_CALL);
+  __ Call(stub.GetCode(), RelocInfo::CONSTRUCT_CALL);
+
+  __ Drop(1);
+
+  context()->Plug(result_register());
+}
+
+
 void FullCodeGenerator::EmitRegExpConstructResult(CallRuntime* expr) {
   RegExpConstructResultStub stub(isolate());
   ZoneList<Expression*>* args = expr->arguments();
   DCHECK(args->length() == 3);
   VisitForStackValue(args->at(0));
   VisitForStackValue(args->at(1));
   VisitForAccumulatorValue(args->at(2));
   __ mov(a0, result_register());
   __ pop(a1);
   __ pop(a2);
@@ skipping 1188 matching lines @@
       Assembler::target_address_at(pc_immediate_load_address)) ==
          reinterpret_cast<uint32_t>(
              isolate->builtins()->OsrAfterStackCheck()->entry()));
   return OSR_AFTER_STACK_CHECK;
 }
 
 
 } }  // namespace v8::internal
 
 #endif  // V8_TARGET_ARCH_MIPS