[turbofan] Use FrameStatesBeforeAndAfter to simplify handling of before/after frame states in AstGraphBuilder.

R=jarin@chromium.org BUG= Review URL: https://codereview.chromium.org/1128193005 Cr-Commit-Position: refs/heads/master@{#28361}
2015-05-12 05:30:27 -07:00 · 2015-05-12 05:30:27 -07:00 · 0c80fdc61e
commit 0c80fdc61e
parent 7fcbeb289d
2 changed files with 121 additions and 92 deletions
--- a/src/compiler/ast-graph-builder.cc
+++ b/src/compiler/ast-graph-builder.cc
@ -384,6 +384,48 @@ class AstGraphBuilder::ControlScopeForFinally : public ControlScope {
 };


+// Helper for generating before and after frame states.
+class AstGraphBuilder::FrameStateBeforeAndAfter {
+ public:
+  FrameStateBeforeAndAfter(AstGraphBuilder* builder, BailoutId id_before)
+      : builder_(builder), frame_state_before_(nullptr) {
+    frame_state_before_ = id_before == BailoutId::None()
+                              ? builder_->jsgraph()->EmptyFrameState()
+                              : builder_->environment()->Checkpoint(id_before);
+  }
+
+  void AddToNode(Node* node, BailoutId id_after,
+                 OutputFrameStateCombine combine) {
+    int count = OperatorProperties::GetFrameStateInputCount(node->op());
+    DCHECK_LE(count, 2);
+
+    if (count >= 1) {
+      // Add the frame state for after the operation.
+      DCHECK_EQ(IrOpcode::kDead,
+                NodeProperties::GetFrameStateInput(node, 0)->opcode());
+
+      Node* frame_state_after =
+          id_after == BailoutId::None()
+              ? builder_->jsgraph()->EmptyFrameState()
+              : builder_->environment()->Checkpoint(id_after, combine);
+
+      NodeProperties::ReplaceFrameStateInput(node, 0, frame_state_after);
+    }
+
+    if (count >= 2) {
+      // Add the frame state for before the operation.
+      DCHECK_EQ(IrOpcode::kDead,
+                NodeProperties::GetFrameStateInput(node, 1)->opcode());
+      NodeProperties::ReplaceFrameStateInput(node, 1, frame_state_before_);
+    }
+  }
+
+ private:
+  AstGraphBuilder* builder_;
+  Node* frame_state_before_;
+};
+
+
 AstGraphBuilder::AstGraphBuilder(Zone* local_zone, CompilationInfo* info,
                                 JSGraph* jsgraph, LoopAssignmentAnalysis* loop,
                                 JSTypeFeedbackTable* js_type_feedback)
@ -1304,14 +1346,15 @@ void AstGraphBuilder::VisitForInBody(ForInStatement* stmt) {
      is_property_missing.If(property_missing);
      is_property_missing.Then();
      // Inc counter and continue.
-      Node* index_inc =
-          NewNode(javascript()->Add(LanguageMode::SLOPPY), index,
-                  jsgraph()->OneConstant());
-      // TODO(jarin): provide real bailout id.
-      PrepareFrameStateAfterAndBefore(index_inc, BailoutId::None(),
-                                      OutputFrameStateCombine::Ignore(),
-                                      jsgraph()->EmptyFrameState());
-      environment()->Poke(0, index_inc);
+      {
+        // TODO(jarin): provide real bailout id.
+        FrameStateBeforeAndAfter states(this, BailoutId::None());
+        Node* index_inc = NewNode(javascript()->Add(LanguageMode::SLOPPY),
+                                  index, jsgraph()->OneConstant());
+        states.AddToNode(index_inc, BailoutId::None(),
+                         OutputFrameStateCombine::Ignore());
+        environment()->Poke(0, index_inc);
+      }
      for_loop.Continue();
      is_property_missing.Else();
      is_property_missing.End();
@ -1332,10 +1375,12 @@ void AstGraphBuilder::VisitForInBody(ForInStatement* stmt) {
  Node* index_inc =
      NewNode(javascript()->Add(LanguageMode::SLOPPY), index,
              jsgraph()->OneConstant());
-  // TODO(jarin): provide real bailout id.
-  PrepareFrameStateAfterAndBefore(index_inc, BailoutId::None(),
-                                  OutputFrameStateCombine::Ignore(),
-                                  jsgraph()->EmptyFrameState());
+  {
+    // TODO(jarin): provide real bailout ids.
+    FrameStateBeforeAndAfter states(this, BailoutId::None());
+    states.AddToNode(index_inc, BailoutId::None(),
+                     OutputFrameStateCombine::Ignore());
+  }
  environment()->Poke(0, index_inc);
  for_loop.EndLoop();
  environment()->Drop(5);
@ -1870,15 +1915,15 @@ void AstGraphBuilder::VisitArrayLiteral(ArrayLiteral* expr) {
    if (CompileTimeValue::IsCompileTimeValue(subexpr)) continue;

    VisitForValue(subexpr);
-    Node* frame_state_before = environment()->Checkpoint(
-        subexpr->id(), OutputFrameStateCombine::PokeAt(0));
-    Node* value = environment()->Pop();
-    Node* index = jsgraph()->Constant(i);
-    Node* store =
-        BuildKeyedStore(literal, index, value, TypeFeedbackId::None());
-    PrepareFrameStateAfterAndBefore(store, expr->GetIdForElement(i),
-                                    OutputFrameStateCombine::Ignore(),
-                                    frame_state_before);
+    {
+      FrameStateBeforeAndAfter states(this, subexpr->id());
+      Node* value = environment()->Pop();
+      Node* index = jsgraph()->Constant(i);
+      Node* store =
+          BuildKeyedStore(literal, index, value, TypeFeedbackId::None());
+      states.AddToNode(store, expr->GetIdForElement(i),
+                       OutputFrameStateCombine::Ignore());
+    }
  }

  environment()->Pop();  // Array literal index.
@ -1916,14 +1961,16 @@ void AstGraphBuilder::VisitForInAssignment(Expression* expr, Node* value,
      environment()->Push(value);
      VisitForValue(property->obj());
      VisitForValue(property->key());
-      Node* key = environment()->Pop();
-      Node* object = environment()->Pop();
-      value = environment()->Pop();
-      Node* store = BuildKeyedStore(object, key, value, TypeFeedbackId::None());
-      // TODO(jarin) Provide a real frame state before.
-      PrepareFrameStateAfterAndBefore(store, bailout_id,
-                                      OutputFrameStateCombine::Ignore(),
-                                      jsgraph()->EmptyFrameState());
+      {
+        // TODO(jarin) Provide a real frame state before.
+        FrameStateBeforeAndAfter states(this, BailoutId::None());
+        Node* key = environment()->Pop();
+        Node* object = environment()->Pop();
+        value = environment()->Pop();
+        Node* store =
+            BuildKeyedStore(object, key, value, TypeFeedbackId::None());
+        states.AddToNode(store, bailout_id, OutputFrameStateCombine::Ignore());
+      }
      break;
    }
  }
@ -1936,12 +1983,19 @@ void AstGraphBuilder::VisitAssignment(Assignment* expr) {
  // Left-hand side can only be a property, a global or a variable slot.
  Property* property = expr->target()->AsProperty();
  LhsKind assign_type = DetermineLhsKind(expr->target());
+  bool needs_frame_state_before = true;

  // Evaluate LHS expression.
  switch (assign_type) {
-    case VARIABLE:
-      // Nothing to do here.
+    case VARIABLE: {
+      Variable* variable = expr->target()->AsVariableProxy()->var();
+      if (variable->location() == Variable::PARAMETER ||
+          variable->location() == Variable::LOCAL ||
+          variable->location() == Variable::CONTEXT) {
+        needs_frame_state_before = false;
+      }
      break;
+    }
    case NAMED_PROPERTY:
      VisitForValue(property->obj());
      break;
@ -1952,10 +2006,9 @@ void AstGraphBuilder::VisitAssignment(Assignment* expr) {
    }
  }

+  BailoutId before_store_id = BailoutId::None();
  // Evaluate the value and potentially handle compound assignments by loading
  // the left-hand side value and performing a binary operation.
-  Node* frame_state_before_store = nullptr;
-  bool needs_frame_state_before = (assign_type == KEYED_PROPERTY);
  if (expr->is_compound()) {
    Node* old_value = NULL;
    switch (assign_type) {
@ -1991,31 +2044,27 @@ void AstGraphBuilder::VisitAssignment(Assignment* expr) {
    }
    environment()->Push(old_value);
    VisitForValue(expr->value());
-    Node* frame_state_before = environment()->Checkpoint(expr->value()->id());
-    Node* right = environment()->Pop();
-    Node* left = environment()->Pop();
-    Node* value = BuildBinaryOp(left, right, expr->binary_op());
-    PrepareFrameStateAfterAndBefore(value, expr->binary_operation()->id(),
-                                    OutputFrameStateCombine::Push(),
-                                    frame_state_before);
+    Node* value;
+    {
+      FrameStateBeforeAndAfter states(this, expr->value()->id());
+      Node* right = environment()->Pop();
+      Node* left = environment()->Pop();
+      value = BuildBinaryOp(left, right, expr->binary_op());
+      states.AddToNode(value, expr->binary_operation()->id(),
+                       OutputFrameStateCombine::Push());
+    }
    environment()->Push(value);
    if (needs_frame_state_before) {
-      frame_state_before_store = environment()->Checkpoint(
-          expr->binary_operation()->id(), OutputFrameStateCombine::PokeAt(0));
+      before_store_id = expr->binary_operation()->id();
    }
  } else {
    VisitForValue(expr->value());
    if (needs_frame_state_before) {
-      // This frame state can be used for lazy-deopting from a to-number
-      // conversion if we are storing into a typed array. It is important
-      // that the frame state is usable for such lazy deopt (i.e., it has
-      // to specify how to override the value before the conversion, in this
-      // case, it overwrites the stack top).
-      frame_state_before_store = environment()->Checkpoint(
-          expr->value()->id(), OutputFrameStateCombine::PokeAt(0));
+      before_store_id = expr->value()->id();
    }
  }

+  FrameStateBeforeAndAfter store_states(this, before_store_id);
  // Store the value.
  Node* value = environment()->Pop();
  switch (assign_type) {
@ -2030,7 +2079,8 @@ void AstGraphBuilder::VisitAssignment(Assignment* expr) {
      Handle<Name> name = property->key()->AsLiteral()->AsPropertyName();
      Node* store =
          BuildNamedStore(object, name, value, expr->AssignmentFeedbackId());
-      PrepareFrameState(store, expr->id(), ast_context()->GetStateCombine());
+      store_states.AddToNode(store, expr->id(),
+                             ast_context()->GetStateCombine());
      break;
    }
    case KEYED_PROPERTY: {
@ -2038,9 +2088,8 @@ void AstGraphBuilder::VisitAssignment(Assignment* expr) {
      Node* object = environment()->Pop();
      Node* store =
          BuildKeyedStore(object, key, value, expr->AssignmentFeedbackId());
-      PrepareFrameStateAfterAndBefore(store, expr->id(),
-                                      ast_context()->GetStateCombine(),
-                                      frame_state_before_store);
+      store_states.AddToNode(store, expr->id(),
+                             ast_context()->GetStateCombine());
      break;
    }
  }
@ -2362,22 +2411,25 @@ void AstGraphBuilder::VisitCountOperation(CountOperation* expr) {
  PrepareFrameState(old_value, expr->ToNumberId(),
                    OutputFrameStateCombine::Push());

-  Node* frame_state_before_store =
-      assign_type == KEYED_PROPERTY
-          ? environment()->Checkpoint(expr->ToNumberId())
-          : nullptr;
+  // TODO(titzer): combine this framestate with the above?
+  FrameStateBeforeAndAfter store_states(this, assign_type == KEYED_PROPERTY
+                                                  ? expr->ToNumberId()
+                                                  : BailoutId::None());

  // Save result for postfix expressions at correct stack depth.
  if (is_postfix) environment()->Poke(stack_depth, old_value);

  // Create node to perform +1/-1 operation.
-  Node* value =
-      BuildBinaryOp(old_value, jsgraph()->OneConstant(), expr->binary_op());
-  // This should never deoptimize because we have converted to number
-  // before.
-  PrepareFrameStateAfterAndBefore(value, BailoutId::None(),
-                                  OutputFrameStateCombine::Ignore(),
-                                  jsgraph()->EmptyFrameState());
+  Node* value;
+  {
+    FrameStateBeforeAndAfter states(this, BailoutId::None());
+    value =
+        BuildBinaryOp(old_value, jsgraph()->OneConstant(), expr->binary_op());
+    // This should never deoptimize because we have converted to number
+    // before.
+    states.AddToNode(value, BailoutId::None(),
+                     OutputFrameStateCombine::Ignore());
+  }

  // Store the value.
  switch (assign_type) {
@ -2405,9 +2457,8 @@ void AstGraphBuilder::VisitCountOperation(CountOperation* expr) {
      Node* store =
          BuildKeyedStore(object, key, value, expr->CountStoreFeedbackId());
      environment()->Push(value);
-      PrepareFrameStateAfterAndBefore(store, expr->AssignmentId(),
-                                      OutputFrameStateCombine::Ignore(),
-                                      frame_state_before_store);
+      store_states.AddToNode(store, expr->AssignmentId(),
+                             OutputFrameStateCombine::Ignore());
      environment()->Pop();
      break;
    }
@ -2430,13 +2481,11 @@ void AstGraphBuilder::VisitBinaryOperation(BinaryOperation* expr) {
    default: {
      VisitForValue(expr->left());
      VisitForValue(expr->right());
-      Node* frame_state_before = environment()->Checkpoint(expr->right()->id());
+      FrameStateBeforeAndAfter states(this, expr->right()->id());
      Node* right = environment()->Pop();
      Node* left = environment()->Pop();
      Node* value = BuildBinaryOp(left, right, expr->op());
-      PrepareFrameStateAfterAndBefore(value, expr->id(),
-                                      ast_context()->GetStateCombine(),
-                                      frame_state_before);
+      states.AddToNode(value, expr->id(), ast_context()->GetStateCombine());
      ast_context()->ProduceValue(value);
    }
  }
@ -3297,24 +3346,6 @@ void AstGraphBuilder::PrepareFrameState(Node* node, BailoutId ast_id,
 }


-void AstGraphBuilder::PrepareFrameStateAfterAndBefore(
-    Node* node, BailoutId ast_id, OutputFrameStateCombine combine,
-    Node* frame_state_before) {
-  if (OperatorProperties::GetFrameStateInputCount(node->op()) > 0) {
-    DCHECK_EQ(2, OperatorProperties::GetFrameStateInputCount(node->op()));
-
-    DCHECK_EQ(IrOpcode::kDead,
-              NodeProperties::GetFrameStateInput(node, 0)->opcode());
-    NodeProperties::ReplaceFrameStateInput(
-        node, 0, environment()->Checkpoint(ast_id, combine));
-
-    DCHECK_EQ(IrOpcode::kDead,
-              NodeProperties::GetFrameStateInput(node, 1)->opcode());
-    NodeProperties::ReplaceFrameStateInput(node, 1, frame_state_before);
-  }
-}
-
-
 BitVector* AstGraphBuilder::GetVariablesAssignedInLoop(
    IterationStatement* stmt) {
  if (loop_assignment_analysis_ == NULL) return NULL;
--- a/src/compiler/ast-graph-builder.h
+++ b/src/compiler/ast-graph-builder.h
@ -67,6 +67,7 @@ class AstGraphBuilder : public AstVisitor {
  class ControlScopeForCatch;
  class ControlScopeForFinally;
  class Environment;
+  class FrameStateBeforeAndAfter;
  friend class ControlBuilder;

  Zone* local_zone_;
@ -212,9 +213,6 @@ class AstGraphBuilder : public AstVisitor {
  void PrepareFrameState(
      Node* node, BailoutId ast_id,
      OutputFrameStateCombine combine = OutputFrameStateCombine::Ignore());
-  void PrepareFrameStateAfterAndBefore(Node* node, BailoutId ast_id,
-                                       OutputFrameStateCombine combine,
-                                       Node* frame_state_before);

  BitVector* GetVariablesAssignedInLoop(IterationStatement* stmt);