[fullcodegen] Implement control flow across do-expressions.

This implements proper handling of local control flow (i.e. break and
continue) that spans the boundary of a do-expression. We can no longer
determine the number of operands to be dropped from the nesting of
statements alone, instead we use the new precise operand stack depth
tracking.

R=jarin@chromium.org
TEST=mjsunit/harmony/do-expressions-control
BUG=v8:4488
LOG=n

Review URL: https://codereview.chromium.org/1724753002

Cr-Commit-Position: refs/heads/master@{#34246}

src/full-codegen/arm/full-codegen-arm.cc

@@ -994,14 +994,14 @@ void FullCodeGenerator::VisitForInStatement(ForInStatement* stmt) {
 
   FeedbackVectorSlot slot = stmt->ForInFeedbackSlot();
 
-  Label loop, exit;
-  ForIn loop_statement(this, stmt);
-  increment_loop_depth();
-
   // Get the object to enumerate over.
   SetExpressionAsStatementPosition(stmt->enumerable());
   VisitForAccumulatorValue(stmt->enumerable());
-  OperandStackDepthIncrement(ForIn::kElementCount);
+  OperandStackDepthIncrement(5);
+
+  Label loop, exit;
+  Iteration loop_statement(this, stmt);
+  increment_loop_depth();
 
   // If the object is null or undefined, skip over the loop, otherwise convert
   // it to a JS receiver.  See ECMA-262 version 5, section 12.6.4.
@@ -1888,7 +1888,7 @@ void FullCodeGenerator::VisitYield(Yield* expr) {
     case Yield::kSuspend:
       // Pop value from top-of-stack slot; box result into result register.
       EmitCreateIteratorResult(false);
-      __ push(result_register());
+      PushOperand(result_register());
       // Fall through.
     case Yield::kInitial: {
       Label suspend, continuation, post_runtime, resume;
@@ -1907,6 +1907,7 @@ void FullCodeGenerator::VisitYield(Yield* expr) {
       EmitUnwindAndReturn();
 
       __ bind(&suspend);
+      OperandStackDepthIncrement(1);  // Not popped on this path.
       VisitForAccumulatorValue(expr->generator_object());
       DCHECK(continuation.pos() > 0 && Smi::IsValid(continuation.pos()));
       __ mov(r1, Operand(Smi::FromInt(continuation.pos())));
@@ -1932,7 +1933,6 @@ void FullCodeGenerator::VisitYield(Yield* expr) {
 
     case Yield::kFinal: {
       // Pop value from top-of-stack slot, box result into result register.
-      OperandStackDepthDecrement(1);
       EmitCreateIteratorResult(true);
       EmitUnwindAndReturn();
       break;
@@ -2081,7 +2081,7 @@ void FullCodeGenerator::EmitCreateIteratorResult(bool done) {
 
   __ bind(&done_allocate);
   __ LoadNativeContextSlot(Context::ITERATOR_RESULT_MAP_INDEX, r1);
-  __ pop(r2);
+  PopOperand(r2);
   __ LoadRoot(r3,
               done ? Heap::kTrueValueRootIndex : Heap::kFalseValueRootIndex);
   __ LoadRoot(r4, Heap::kEmptyFixedArrayRootIndex);

src/full-codegen/arm64/full-codegen-arm64.cc

@@ -997,14 +997,14 @@ void FullCodeGenerator::VisitForInStatement(ForInStatement* stmt) {
 
   // TODO(all): This visitor probably needs better comments and a revisit.
 
-  Label loop, exit;
-  ForIn loop_statement(this, stmt);
-  increment_loop_depth();
-
   // Get the object to enumerate over.
   SetExpressionAsStatementPosition(stmt->enumerable());
   VisitForAccumulatorValue(stmt->enumerable());
-  OperandStackDepthIncrement(ForIn::kElementCount);
+  OperandStackDepthIncrement(5);
+
+  Label loop, exit;
+  Iteration loop_statement(this, stmt);
+  increment_loop_depth();
 
   // If the object is null or undefined, skip over the loop, otherwise convert
   // it to a JS receiver.  See ECMA-262 version 5, section 12.6.4.
@@ -3874,7 +3874,7 @@ void FullCodeGenerator::VisitYield(Yield* expr) {
     case Yield::kSuspend:
       // Pop value from top-of-stack slot; box result into result register.
       EmitCreateIteratorResult(false);
-      __ Push(result_register());
+      PushOperand(result_register());
       // Fall through.
     case Yield::kInitial: {
       Label suspend, continuation, post_runtime, resume;
@@ -3896,6 +3896,7 @@ void FullCodeGenerator::VisitYield(Yield* expr) {
       EmitUnwindAndReturn();
 
       __ Bind(&suspend);
+      OperandStackDepthIncrement(1);  // Not popped on this path.
       VisitForAccumulatorValue(expr->generator_object());
       DCHECK((continuation.pos() > 0) && Smi::IsValid(continuation.pos()));
       __ Mov(x1, Smi::FromInt(continuation.pos()));
@@ -3921,7 +3922,6 @@ void FullCodeGenerator::VisitYield(Yield* expr) {
 
     case Yield::kFinal: {
       // Pop value from top-of-stack slot, box result into result register.
-      OperandStackDepthDecrement(1);
       EmitCreateIteratorResult(true);
       EmitUnwindAndReturn();
       break;
@@ -4079,7 +4079,7 @@ void FullCodeGenerator::EmitCreateIteratorResult(bool done) {
   Register empty_fixed_array = x4;
   Register untagged_result = x5;
   __ LoadNativeContextSlot(Context::ITERATOR_RESULT_MAP_INDEX, map_reg);
-  __ Pop(result_value);
+  PopOperand(result_value);
   __ LoadRoot(boolean_done,
               done ? Heap::kTrueValueRootIndex : Heap::kFalseValueRootIndex);
   __ LoadRoot(empty_fixed_array, Heap::kEmptyFixedArrayRootIndex);

src/full-codegen/full-codegen.cc

@@ -913,7 +913,6 @@ void FullCodeGenerator::VisitIfStatement(IfStatement* stmt) {
 
 void FullCodeGenerator::EmitContinue(Statement* target) {
   NestedStatement* current = nesting_stack_;
-  int stack_depth = 0;
   int context_length = 0;
   // When continuing, we clobber the unpredictable value in the accumulator
   // with one that's safe for GC.  If we hit an exit from the try block of
@@ -923,15 +922,17 @@ void FullCodeGenerator::EmitContinue(Statement* target) {
   while (!current->IsContinueTarget(target)) {
     if (current->IsTryFinally()) {
       Comment cmnt(masm(), "[ Deferred continue through finally");
-      current->Exit(&stack_depth, &context_length);
+      current->Exit(&context_length);
-      DCHECK_EQ(0, stack_depth);
+      DCHECK_EQ(-1, context_length);
-      DCHECK_EQ(0, context_length);
       current->AsTryFinally()->deferred_commands()->RecordContinue(target);
       return;
     }
-    current = current->Exit(&stack_depth, &context_length);
+    current = current->Exit(&context_length);
   }
-  __ Drop(stack_depth);
+  int stack_depth = current->GetStackDepthAtTarget();
+  int stack_drop = operand_stack_depth_ - stack_depth;
+  DCHECK_GE(stack_drop, 0);
+  __ Drop(stack_drop);
   if (context_length > 0) {
     while (context_length > 0) {
       LoadContextField(context_register(), Context::PREVIOUS_INDEX);
@@ -952,7 +953,6 @@ void FullCodeGenerator::VisitContinueStatement(ContinueStatement* stmt) {
 
 void FullCodeGenerator::EmitBreak(Statement* target) {
   NestedStatement* current = nesting_stack_;
-  int stack_depth = 0;
   int context_length = 0;
   // When breaking, we clobber the unpredictable value in the accumulator
   // with one that's safe for GC.  If we hit an exit from the try block of
@@ -962,15 +962,17 @@ void FullCodeGenerator::EmitBreak(Statement* target) {
   while (!current->IsBreakTarget(target)) {
     if (current->IsTryFinally()) {
       Comment cmnt(masm(), "[ Deferred break through finally");
-      current->Exit(&stack_depth, &context_length);
+      current->Exit(&context_length);
-      DCHECK_EQ(0, stack_depth);
+      DCHECK_EQ(-1, context_length);
-      DCHECK_EQ(0, context_length);
       current->AsTryFinally()->deferred_commands()->RecordBreak(target);
       return;
     }
-    current = current->Exit(&stack_depth, &context_length);
+    current = current->Exit(&context_length);
   }
-  __ Drop(stack_depth);
+  int stack_depth = current->GetStackDepthAtTarget();
+  int stack_drop = operand_stack_depth_ - stack_depth;
+  DCHECK_GE(stack_drop, 0);
+  __ Drop(stack_drop);
   if (context_length > 0) {
     while (context_length > 0) {
       LoadContextField(context_register(), Context::PREVIOUS_INDEX);
@@ -991,20 +993,17 @@ void FullCodeGenerator::VisitBreakStatement(BreakStatement* stmt) {
 
 void FullCodeGenerator::EmitUnwindAndReturn() {
   NestedStatement* current = nesting_stack_;
-  int stack_depth = 0;
   int context_length = 0;
   while (current != NULL) {
     if (current->IsTryFinally()) {
       Comment cmnt(masm(), "[ Deferred return through finally");
-      current->Exit(&stack_depth, &context_length);
+      current->Exit(&context_length);
-      DCHECK_EQ(0, stack_depth);
+      DCHECK_EQ(-1, context_length);
-      DCHECK_EQ(0, context_length);
       current->AsTryFinally()->deferred_commands()->RecordReturn();
       return;
     }
-    current = current->Exit(&stack_depth, &context_length);
+    current = current->Exit(&context_length);
   }
-  __ Drop(stack_depth);
   EmitReturnSequence();
 }
 
@@ -1281,7 +1280,8 @@ void FullCodeGenerator::VisitTryCatchStatement(TryCatchStatement* stmt) {
   try_catch_depth_++;
   int handler_index = NewHandlerTableEntry();
   EnterTryBlock(handler_index, &handler_entry);
-  { TryCatch try_body(this);
+  {
+    Comment cmnt_try(masm(), "[ Try block");
     Visit(stmt->try_block());
   }
   ExitTryBlock(handler_index);
@@ -1322,7 +1322,7 @@ void FullCodeGenerator::VisitTryFinallyStatement(TryFinallyStatement* stmt) {
   // Exception handler code.  This code is only executed when an exception
   // is thrown.  Record the continuation and jump to the finally block.
   {
-    Comment cmt_handler(masm(), "[ Finally handler");
+    Comment cmnt_handler(masm(), "[ Finally handler");
     deferred.RecordThrow();
   }
 
@@ -1331,6 +1331,7 @@ void FullCodeGenerator::VisitTryFinallyStatement(TryFinallyStatement* stmt) {
   int handler_index = NewHandlerTableEntry();
   EnterTryBlock(handler_index, &handler_entry);
   {
+    Comment cmnt_try(masm(), "[ Try block");
     TryFinally try_body(this, &deferred);
     Visit(stmt->try_block());
   }
@@ -1345,15 +1346,14 @@ void FullCodeGenerator::VisitTryFinallyStatement(TryFinallyStatement* stmt) {
 
   // Finally block implementation.
   __ bind(&finally_entry);
-  Comment cmnt_finally(masm(), "[ Finally block");
-  OperandStackDepthIncrement(2);  // Token and accumulator are on stack.
-  EnterFinallyBlock();
   {
-    Finally finally_body(this);
+    Comment cmnt_finally(masm(), "[ Finally block");
+    OperandStackDepthIncrement(2);  // Token and accumulator are on stack.
+    EnterFinallyBlock();
     Visit(stmt->finally_block());
+    ExitFinallyBlock();
+    OperandStackDepthDecrement(2);  // Token and accumulator were on stack.
   }
-  ExitFinallyBlock();
-  OperandStackDepthDecrement(2);  // Token and accumulator were on stack.
 
   {
     Comment cmnt_deferred(masm(), "[ Post-finally dispatch");
@@ -1599,28 +1599,32 @@ void FullCodeGenerator::VisitRewritableExpression(RewritableExpression* expr) {
   Visit(expr->expression());
 }
 
-
 FullCodeGenerator::NestedStatement* FullCodeGenerator::TryFinally::Exit(
-    int* stack_depth, int* context_length) {
+    int* context_length) {
   // The macros used here must preserve the result register.
 
+  // Calculate how many operands to drop to get down to handler block.
+  int stack_drop = codegen_->operand_stack_depth_ - GetStackDepthAtTarget();
+  DCHECK_GE(stack_drop, 0);
+
   // Because the handler block contains the context of the finally
   // code, we can restore it directly from there for the finally code
   // rather than iteratively unwinding contexts via their previous
   // links.
   if (*context_length > 0) {
-    __ Drop(*stack_depth);  // Down to the handler block.
+    __ Drop(stack_drop);  // Down to the handler block.
     // Restore the context to its dedicated register and the stack.
-    STATIC_ASSERT(TryFinally::kElementCount == 1);
+    STATIC_ASSERT(TryBlockConstant::kElementCount == 1);
     __ Pop(codegen_->context_register());
     codegen_->StoreToFrameField(StandardFrameConstants::kContextOffset,
                                 codegen_->context_register());
   } else {
     // Down to the handler block and also drop context.
-    __ Drop(*stack_depth + kElementCount);
+    __ Drop(stack_drop + TryBlockConstant::kElementCount);
   }
-  *stack_depth = 0;
+
-  *context_length = 0;
+  // The caller will ignore outputs.
+  *context_length = -1;
   return previous_;
 }
 

src/full-codegen/full-codegen.h

@@ -108,7 +108,9 @@ class FullCodeGenerator: public AstVisitor {
 
   class NestedStatement BASE_EMBEDDED {
    public:
-    explicit NestedStatement(FullCodeGenerator* codegen) : codegen_(codegen) {
+    explicit NestedStatement(FullCodeGenerator* codegen)
+        : codegen_(codegen),
+          stack_depth_at_target_(codegen->operand_stack_depth_) {
       // Link into codegen's nesting stack.
       previous_ = codegen->nesting_stack_;
       codegen->nesting_stack_ = this;
@@ -130,18 +132,20 @@ class FullCodeGenerator: public AstVisitor {
     // Notify the statement that we are exiting it via break, continue, or
     // return and give it a chance to generate cleanup code.  Return the
     // next outer statement in the nesting stack.  We accumulate in
-    // *stack_depth the amount to drop the stack and in *context_length the
+    // {*context_length} the number of context chain links to unwind as we
-    // number of context chain links to unwind as we traverse the nesting
+    // traverse the nesting stack from an exit to its target.
-    // stack from an exit to its target.
+    virtual NestedStatement* Exit(int* context_length) { return previous_; }
-    virtual NestedStatement* Exit(int* stack_depth, int* context_length) {
+
-      return previous_;
+    // Determine the expected operand stack depth when this statement is being
-    }
+    // used as the target of an exit. The caller will drop to this depth.
+    int GetStackDepthAtTarget() { return stack_depth_at_target_; }
 
    protected:
     MacroAssembler* masm() { return codegen_->masm(); }
 
     FullCodeGenerator* codegen_;
     NestedStatement* previous_;
+    int stack_depth_at_target_;
 
    private:
     DISALLOW_COPY_AND_ASSIGN(NestedStatement);
@@ -192,7 +196,7 @@ class FullCodeGenerator: public AstVisitor {
         : Breakable(codegen, block) {
     }
 
-    NestedStatement* Exit(int* stack_depth, int* context_length) override {
+    NestedStatement* Exit(int* context_length) override {
       auto block_scope = statement()->AsBlock()->scope();
       if (block_scope != nullptr) {
         if (block_scope->ContextLocalCount() > 0) ++(*context_length);
@@ -201,19 +205,6 @@ class FullCodeGenerator: public AstVisitor {
     }
   };
 
-  // The try block of a try/catch statement.
-  class TryCatch : public NestedStatement {
-   public:
-    static const int kElementCount = TryBlockConstant::kElementCount;
-
-    explicit TryCatch(FullCodeGenerator* codegen) : NestedStatement(codegen) {}
-
-    NestedStatement* Exit(int* stack_depth, int* context_length) override {
-      *stack_depth += kElementCount;
-      return previous_;
-    }
-  };
-
   class DeferredCommands {
    public:
     enum Command { kReturn, kThrow, kBreak, kContinue };
@@ -254,12 +245,10 @@ class FullCodeGenerator: public AstVisitor {
   // The try block of a try/finally statement.
   class TryFinally : public NestedStatement {
    public:
-    static const int kElementCount = TryBlockConstant::kElementCount;
-
     TryFinally(FullCodeGenerator* codegen, DeferredCommands* commands)
         : NestedStatement(codegen), deferred_commands_(commands) {}
 
-    NestedStatement* Exit(int* stack_depth, int* context_length) override;
+    NestedStatement* Exit(int* context_length) override;
 
     bool IsTryFinally() override { return true; }
     TryFinally* AsTryFinally() override { return this; }
@@ -270,35 +259,6 @@ class FullCodeGenerator: public AstVisitor {
     DeferredCommands* deferred_commands_;
   };
 
-  // The finally block of a try/finally statement.
-  class Finally : public NestedStatement {
-   public:
-    static const int kElementCount = 3;
-
-    explicit Finally(FullCodeGenerator* codegen) : NestedStatement(codegen) {}
-
-    NestedStatement* Exit(int* stack_depth, int* context_length) override {
-      *stack_depth += kElementCount;
-      return previous_;
-    }
-  };
-
-  // The body of a for/in loop.
-  class ForIn : public Iteration {
-   public:
-    static const int kElementCount = 5;
-
-    ForIn(FullCodeGenerator* codegen, ForInStatement* statement)
-        : Iteration(codegen, statement) {
-    }
-
-    NestedStatement* Exit(int* stack_depth, int* context_length) override {
-      *stack_depth += kElementCount;
-      return previous_;
-    }
-  };
-
-
   // The body of a with or catch.
   class WithOrCatch : public NestedStatement {
    public:
@@ -306,7 +266,7 @@ class FullCodeGenerator: public AstVisitor {
         : NestedStatement(codegen) {
     }
 
-    NestedStatement* Exit(int* stack_depth, int* context_length) override {
+    NestedStatement* Exit(int* context_length) override {
       ++(*context_length);
       return previous_;
     }

src/full-codegen/ia32/full-codegen-ia32.cc

@@ -934,14 +934,14 @@ void FullCodeGenerator::VisitForInStatement(ForInStatement* stmt) {
 
   FeedbackVectorSlot slot = stmt->ForInFeedbackSlot();
 
-  Label loop, exit;
-  ForIn loop_statement(this, stmt);
-  increment_loop_depth();
-
   // Get the object to enumerate over.
   SetExpressionAsStatementPosition(stmt->enumerable());
   VisitForAccumulatorValue(stmt->enumerable());
-  OperandStackDepthIncrement(ForIn::kElementCount);
+  OperandStackDepthIncrement(5);
+
+  Label loop, exit;
+  Iteration loop_statement(this, stmt);
+  increment_loop_depth();
 
   // If the object is null or undefined, skip over the loop, otherwise convert
   // it to a JS receiver.  See ECMA-262 version 5, section 12.6.4.
@@ -1089,8 +1089,7 @@ void FullCodeGenerator::VisitForInStatement(ForInStatement* stmt) {
 
   // Remove the pointers stored on the stack.
   __ bind(loop_statement.break_label());
-  __ add(esp, Immediate(5 * kPointerSize));
+  DropOperands(5);
-  OperandStackDepthDecrement(ForIn::kElementCount);
 
   // Exit and decrement the loop depth.
   PrepareForBailoutForId(stmt->ExitId(), NO_REGISTERS);
@@ -1805,7 +1804,7 @@ void FullCodeGenerator::VisitYield(Yield* expr) {
     case Yield::kSuspend:
       // Pop value from top-of-stack slot; box result into result register.
       EmitCreateIteratorResult(false);
-      __ push(result_register());
+      PushOperand(result_register());
       // Fall through.
     case Yield::kInitial: {
       Label suspend, continuation, post_runtime, resume;
@@ -1824,6 +1823,7 @@ void FullCodeGenerator::VisitYield(Yield* expr) {
       EmitUnwindAndReturn();
 
       __ bind(&suspend);
+      OperandStackDepthIncrement(1);  // Not popped on this path.
       VisitForAccumulatorValue(expr->generator_object());
       DCHECK(continuation.pos() > 0 && Smi::IsValid(continuation.pos()));
       __ mov(FieldOperand(eax, JSGeneratorObject::kContinuationOffset),
@@ -1850,7 +1850,6 @@ void FullCodeGenerator::VisitYield(Yield* expr) {
 
     case Yield::kFinal: {
       // Pop value from top-of-stack slot, box result into result register.
-      OperandStackDepthDecrement(1);
       EmitCreateIteratorResult(true);
       EmitUnwindAndReturn();
       break;
@@ -1991,6 +1990,7 @@ void FullCodeGenerator::EmitCreateIteratorResult(bool done) {
   __ mov(FieldOperand(eax, JSIteratorResult::kDoneOffset),
          isolate()->factory()->ToBoolean(done));
   STATIC_ASSERT(JSIteratorResult::kSize == 5 * kPointerSize);
+  OperandStackDepthDecrement(1);
 }
 
 

src/full-codegen/mips/full-codegen-mips.cc

@@ -990,15 +990,15 @@ void FullCodeGenerator::VisitForInStatement(ForInStatement* stmt) {
 
   FeedbackVectorSlot slot = stmt->ForInFeedbackSlot();
 
-  Label loop, exit;
-  ForIn loop_statement(this, stmt);
-  increment_loop_depth();
-
   // Get the object to enumerate over.
   SetExpressionAsStatementPosition(stmt->enumerable());
   VisitForAccumulatorValue(stmt->enumerable());
   __ mov(a0, result_register());
-  OperandStackDepthIncrement(ForIn::kElementCount);
+  OperandStackDepthIncrement(5);
+
+  Label loop, exit;
+  Iteration loop_statement(this, stmt);
+  increment_loop_depth();
 
   // If the object is null or undefined, skip over the loop, otherwise convert
   // it to a JS receiver.  See ECMA-262 version 5, section 12.6.4.
@@ -1886,7 +1886,7 @@ void FullCodeGenerator::VisitYield(Yield* expr) {
     case Yield::kSuspend:
       // Pop value from top-of-stack slot; box result into result register.
       EmitCreateIteratorResult(false);
-      __ push(result_register());
+      PushOperand(result_register());
       // Fall through.
     case Yield::kInitial: {
       Label suspend, continuation, post_runtime, resume;
@@ -1905,6 +1905,7 @@ void FullCodeGenerator::VisitYield(Yield* expr) {
       EmitUnwindAndReturn();
 
       __ bind(&suspend);
+      OperandStackDepthIncrement(1);  // Not popped on this path.
       VisitForAccumulatorValue(expr->generator_object());
       DCHECK(continuation.pos() > 0 && Smi::IsValid(continuation.pos()));
       __ li(a1, Operand(Smi::FromInt(continuation.pos())));
@@ -1929,7 +1930,6 @@ void FullCodeGenerator::VisitYield(Yield* expr) {
 
     case Yield::kFinal: {
       // Pop value from top-of-stack slot, box result into result register.
-      OperandStackDepthDecrement(1);
       EmitCreateIteratorResult(true);
       EmitUnwindAndReturn();
       break;
@@ -2079,7 +2079,7 @@ void FullCodeGenerator::EmitCreateIteratorResult(bool done) {
 
   __ bind(&done_allocate);
   __ LoadNativeContextSlot(Context::ITERATOR_RESULT_MAP_INDEX, a1);
-  __ pop(a2);
+  PopOperand(a2);
   __ LoadRoot(a3,
               done ? Heap::kTrueValueRootIndex : Heap::kFalseValueRootIndex);
   __ LoadRoot(t0, Heap::kEmptyFixedArrayRootIndex);

src/full-codegen/mips64/full-codegen-mips64.cc

@@ -990,16 +990,16 @@ void FullCodeGenerator::VisitForInStatement(ForInStatement* stmt) {
 
   FeedbackVectorSlot slot = stmt->ForInFeedbackSlot();
 
-  Label loop, exit;
-  ForIn loop_statement(this, stmt);
-  increment_loop_depth();
-
   // Get the object to enumerate over. If the object is null or undefined, skip
   // over the loop.  See ECMA-262 version 5, section 12.6.4.
   SetExpressionAsStatementPosition(stmt->enumerable());
   VisitForAccumulatorValue(stmt->enumerable());
   __ mov(a0, result_register());
-  OperandStackDepthIncrement(ForIn::kElementCount);
+  OperandStackDepthIncrement(5);
+
+  Label loop, exit;
+  Iteration loop_statement(this, stmt);
+  increment_loop_depth();
 
   // If the object is null or undefined, skip over the loop, otherwise convert
   // it to a JS receiver.  See ECMA-262 version 5, section 12.6.4.
@@ -1888,7 +1888,7 @@ void FullCodeGenerator::VisitYield(Yield* expr) {
     case Yield::kSuspend:
       // Pop value from top-of-stack slot; box result into result register.
       EmitCreateIteratorResult(false);
-      __ push(result_register());
+      PushOperand(result_register());
       // Fall through.
     case Yield::kInitial: {
       Label suspend, continuation, post_runtime, resume;
@@ -1907,6 +1907,7 @@ void FullCodeGenerator::VisitYield(Yield* expr) {
       EmitUnwindAndReturn();
 
       __ bind(&suspend);
+      OperandStackDepthIncrement(1);  // Not popped on this path.
       VisitForAccumulatorValue(expr->generator_object());
       DCHECK(continuation.pos() > 0 && Smi::IsValid(continuation.pos()));
       __ li(a1, Operand(Smi::FromInt(continuation.pos())));
@@ -1931,7 +1932,6 @@ void FullCodeGenerator::VisitYield(Yield* expr) {
 
     case Yield::kFinal: {
       // Pop value from top-of-stack slot, box result into result register.
-      OperandStackDepthDecrement(1);
       EmitCreateIteratorResult(true);
       EmitUnwindAndReturn();
       break;
@@ -2083,7 +2083,7 @@ void FullCodeGenerator::EmitCreateIteratorResult(bool done) {
 
   __ bind(&done_allocate);
   __ LoadNativeContextSlot(Context::ITERATOR_RESULT_MAP_INDEX, a1);
-  __ pop(a2);
+  PopOperand(a2);
   __ LoadRoot(a3,
               done ? Heap::kTrueValueRootIndex : Heap::kFalseValueRootIndex);
   __ LoadRoot(a4, Heap::kEmptyFixedArrayRootIndex);

src/full-codegen/x64/full-codegen-x64.cc

@@ -947,14 +947,14 @@ void FullCodeGenerator::VisitForInStatement(ForInStatement* stmt) {
 
   FeedbackVectorSlot slot = stmt->ForInFeedbackSlot();
 
-  Label loop, exit;
-  ForIn loop_statement(this, stmt);
-  increment_loop_depth();
-
   // Get the object to enumerate over.
   SetExpressionAsStatementPosition(stmt->enumerable());
   VisitForAccumulatorValue(stmt->enumerable());
-  OperandStackDepthIncrement(ForIn::kElementCount);
+  OperandStackDepthIncrement(5);
+
+  Label loop, exit;
+  Iteration loop_statement(this, stmt);
+  increment_loop_depth();
 
   // If the object is null or undefined, skip over the loop, otherwise convert
   // it to a JS receiver.  See ECMA-262 version 5, section 12.6.4.
@@ -1115,8 +1115,7 @@ void FullCodeGenerator::VisitForInStatement(ForInStatement* stmt) {
 
   // Remove the pointers stored on the stack.
   __ bind(loop_statement.break_label());
-  __ addp(rsp, Immediate(5 * kPointerSize));
+  DropOperands(5);
-  OperandStackDepthDecrement(ForIn::kElementCount);
 
   // Exit and decrement the loop depth.
   PrepareForBailoutForId(stmt->ExitId(), NO_REGISTERS);
@@ -1828,7 +1827,7 @@ void FullCodeGenerator::VisitYield(Yield* expr) {
     case Yield::kSuspend:
       // Pop value from top-of-stack slot; box result into result register.
       EmitCreateIteratorResult(false);
-      __ Push(result_register());
+      PushOperand(result_register());
       // Fall through.
     case Yield::kInitial: {
       Label suspend, continuation, post_runtime, resume;
@@ -1847,6 +1846,7 @@ void FullCodeGenerator::VisitYield(Yield* expr) {
       EmitUnwindAndReturn();
 
       __ bind(&suspend);
+      OperandStackDepthIncrement(1);  // Not popped on this path.
       VisitForAccumulatorValue(expr->generator_object());
       DCHECK(continuation.pos() > 0 && Smi::IsValid(continuation.pos()));
       __ Move(FieldOperand(rax, JSGeneratorObject::kContinuationOffset),
@@ -1874,7 +1874,6 @@ void FullCodeGenerator::VisitYield(Yield* expr) {
 
     case Yield::kFinal: {
       // Pop value from top-of-stack slot, box result into result register.
-      OperandStackDepthDecrement(1);
       EmitCreateIteratorResult(true);
       EmitUnwindAndReturn();
       break;
@@ -2014,6 +2013,7 @@ void FullCodeGenerator::EmitCreateIteratorResult(bool done) {
   __ LoadRoot(FieldOperand(rax, JSIteratorResult::kDoneOffset),
               done ? Heap::kTrueValueRootIndex : Heap::kFalseValueRootIndex);
   STATIC_ASSERT(JSIteratorResult::kSize == 5 * kPointerSize);
+  OperandStackDepthDecrement(1);
 }
 
 

test/mjsunit/harmony/do-expressions-control.js

@@ -0,0 +1,109 @@
+// Copyright 2016 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.
+
+// Flags: --allow-natives-syntax --harmony-do-expressions
+
+(function TestDoForInDoBreak() {
+  function f(o, i) {
+    var a = "result@" + do {
+      var r = "(";
+      for (var x in o) {
+        var b = "end@" + do {
+          if (x == i) { break } else { r += o[x]; x }
+        }
+      }
+      r + ")";
+    }
+    return a + "," + b;
+  }
+  assertEquals("result@(3),end@0", f([3], 2));
+  assertEquals("result@(35),end@1", f([3,5], 2));
+  assertEquals("result@(35),end@1", f([3,5,7], 2));
+  assertEquals("result@(35),end@1", f([3,5,7,9], 2));
+  %OptimizeFunctionOnNextCall(f);
+  assertEquals("result@(3),end@0", f([3], 2));
+  assertEquals("result@(35),end@1", f([3,5], 2));
+  assertEquals("result@(35),end@1", f([3,5,7], 2));
+  assertEquals("result@(35),end@1", f([3,5,7,9], 2));
+})();
+
+(function TestDoForInDoContinue() {
+  function f(o, i) {
+    var a = "result@" + do {
+      var r = "("
+      for (var x in o) {
+        var b = "end@" + do {
+          if (x == i) { continue } else { r += o[x]; x }
+        }
+      }
+      r + ")"
+    }
+    return a + "," + b
+  }
+  assertEquals("result@(3),end@0", f([3], 2));
+  assertEquals("result@(35),end@1", f([3,5], 2));
+  assertEquals("result@(35),end@1", f([3,5,7], 2));
+  assertEquals("result@(359),end@3", f([3,5,7,9], 2));
+  %OptimizeFunctionOnNextCall(f);
+  assertEquals("result@(3),end@0", f([3], 2));
+  assertEquals("result@(35),end@1", f([3,5], 2));
+  assertEquals("result@(35),end@1", f([3,5,7], 2));
+  assertEquals("result@(359),end@3", f([3,5,7,9], 2));
+})();
+
+(function TestDoForNestedWithTargetLabels() {
+  function f(mode) {
+    var loop = true;
+    var head = "<";
+    var tail = ">";
+    var middle =
+    "1" + do { loop1: for(; loop; head += "A") {
+      "2" + do { loop2: for(; loop; head += "B") {
+        "3" + do { loop3: for(; loop; head += "C") {
+          "4" + do { loop4: for(; loop; head += "D") {
+            "5" + do { loop5: for(; loop; head += "E") {
+              "6" + do { loop6: for(; loop; head += "F") {
+                loop = false;
+                switch (mode) {
+                  case "b1": break loop1;
+                  case "b2": break loop2;
+                  case "b3": break loop3;
+                  case "b4": break loop4;
+                  case "b5": break loop5;
+                  case "b6": break loop6;
+                  case "c1": continue loop1;
+                  case "c2": continue loop2;
+                  case "c3": continue loop3;
+                  case "c4": continue loop4;
+                  case "c5": continue loop5;
+                  case "c6": continue loop6;
+                  default: "7";
+                }
+              }}
+            }}
+          }}
+        }}
+      }}
+    }}
+    return head + middle + tail;
+  }
+  function test() {
+    assertEquals(      "<1undefined>",      f("b1"));
+    assertEquals(     "<A1undefined>",      f("c1"));
+    assertEquals(     "<A12undefined>",     f("b2"));
+    assertEquals(    "<BA12undefined>",     f("c2"));
+    assertEquals(    "<BA123undefined>",    f("b3"));
+    assertEquals(   "<CBA123undefined>",    f("c3"));
+    assertEquals(   "<CBA1234undefined>",   f("b4"));
+    assertEquals(  "<DCBA1234undefined>",   f("c4"));
+    assertEquals(  "<DCBA12345undefined>",  f("b5"));
+    assertEquals( "<EDCBA12345undefined>",  f("c5"));
+    assertEquals( "<EDCBA123456undefined>", f("b6"));
+    assertEquals("<FEDCBA123456undefined>", f("c6"));
+    assertEquals("<FEDCBA1234567>",         f("xx"));
+  }
+  test();
+  %OptimizeFunctionOnNextCall(f);
+  test();
+})();