PPC: Handle StepIn for constructors through PrepareStep just like for regular calls

src/full-codegen/ppc/full-codegen-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/code-factory.h"
 #include "src/code-stubs.h"
 #include "src/codegen.h"
 #include "src/debug/debug.h"
@@ skipping 3064 matching lines @@
 
   // Push the arguments ("left-to-right") on the stack.
   ZoneList<Expression*>* args = expr->arguments();
   int arg_count = args->length();
   for (int i = 0; i < arg_count; i++) {
     VisitForStackValue(args->at(i));
   }
 
   // Call the construct call builtin that handles allocation and
   // constructor invocation.
-  SetConstructCallPosition(expr);
+  SetConstructCallPosition(expr, arg_count);
 
   // Load function and argument count into r4 and r3.
   __ mov(r3, Operand(arg_count));
   __ LoadP(r4, MemOperand(sp, arg_count * kPointerSize), r0);
 
   // Record call targets in unoptimized code.
   __ EmitLoadTypeFeedbackVector(r5);
   __ LoadSmiLiteral(r6, SmiFromSlot(expr->CallNewFeedbackSlot()));
 
   CallConstructStub stub(isolate(), RECORD_CONSTRUCTOR_TARGET);
@@ skipping 15 matching lines @@
 
   // Push the arguments ("left-to-right") on the stack.
   ZoneList<Expression*>* args = expr->arguments();
   int arg_count = args->length();
   for (int i = 0; i < arg_count; i++) {
     VisitForStackValue(args->at(i));
   }
 
   // Call the construct call builtin that handles allocation and
   // constructor invocation.
-  SetConstructCallPosition(expr);
+  SetConstructCallPosition(expr, arg_count);
 
   // Load new target into r7.
   VisitForAccumulatorValue(super_call_ref->new_target_var());
   __ mr(r7, result_register());
 
   // Load function and argument count into r1 and r0.
   __ mov(r3, Operand(arg_count));
   __ LoadP(r4, MemOperand(sp, arg_count * kPointerSize));
 
   // Record call targets in unoptimized code.
@@ skipping 711 matching lines @@
   __ LoadP(cp, MemOperand(fp, StandardFrameConstants::kContextOffset));
   // Discard the function left on TOS.
   context()->DropAndPlug(1, r3);
 }
 
 
 void FullCodeGenerator::EmitDefaultConstructorCallSuper(CallRuntime* expr) {
   ZoneList<Expression*>* args = expr->arguments();
   DCHECK(args->length() == 2);
 
-  // Evaluate new.target.
+  // Evaluate new.target and super constructor.
   VisitForStackValue(args->at(0));
+  VisitForStackValue(args->at(1));
 
-  // Evaluate super constructor (to stack and r4).
-  VisitForAccumulatorValue(args->at(1));
-  __ push(result_register());
-  __ mr(r4, result_register());
-
-  // Load new target into r6.
-  __ LoadP(r6, MemOperand(sp, 1 * kPointerSize));
+  // Call the construct call builtin that handles allocation and
+  // constructor invocation.
+  SetConstructCallPosition(expr, 0);
 
   // Check if the calling frame is an arguments adaptor frame.
   Label adaptor_frame, args_set_up, runtime;
   __ LoadP(r5, MemOperand(fp, StandardFrameConstants::kCallerFPOffset));
   __ LoadP(r7, MemOperand(r5, StandardFrameConstants::kContextOffset));
+
+  // Load super constructor, new target into r4, r6.
+  __ LoadP(r4, MemOperand(sp));
+  __ LoadP(r6, MemOperand(sp, 1 * kPointerSize));
+
   __ CmpSmiLiteral(r7, Smi::FromInt(StackFrame::ARGUMENTS_ADAPTOR), r0);
   __ beq(&adaptor_frame);
 
   // default constructor has no arguments, so no adaptor frame means no args.
   __ li(r3, Operand::Zero());
   __ b(&args_set_up);
 
   // Copy arguments from adaptor frame.
   {
     __ bind(&adaptor_frame);
@@ skipping 1163 matching lines @@
     return ON_STACK_REPLACEMENT;
   }
 
   DCHECK(interrupt_address ==
          isolate->builtins()->OsrAfterStackCheck()->entry());
   return OSR_AFTER_STACK_CHECK;
 }
 }  // namespace internal
 }  // namespace v8
 #endif  // V8_TARGET_ARCH_PPC