Add constants for FrameState input parameters

R=jarin@chromium.org

Review URL: https://codereview.chromium.org/1144133003

Cr-Commit-Position: refs/heads/master@{#28519}

src/compiler/frame-states.h

@@ -101,6 +101,13 @@ size_t hash_value(FrameStateCallInfo const&);
 
 std::ostream& operator<<(std::ostream&, FrameStateCallInfo const&);
 
+static const int kFrameStateParametersInput = 0;
+static const int kFrameStateLocalsInput = 1;
+static const int kFrameStateStackInput = 2;
+static const int kFrameStateContextInput = 3;
+static const int kFrameStateFunctionInput = 4;
+static const int kFrameStateOuterStateInput = 5;
+static const int kFrameStateInputCount = kFrameStateOuterStateInput + 1;
 
 }  // namespace compiler
 }  // namespace internal

src/compiler/instruction-selector.cc

@@ -1028,19 +1028,24 @@ void InstructionSelector::VisitThrow(Node* value) {
 FrameStateDescriptor* InstructionSelector::GetFrameStateDescriptor(
     Node* state) {
   DCHECK(state->opcode() == IrOpcode::kFrameState);
-  DCHECK_EQ(6, state->InputCount());
-  DCHECK_EQ(IrOpcode::kTypedStateValues, state->InputAt(0)->opcode());
-  DCHECK_EQ(IrOpcode::kTypedStateValues, state->InputAt(1)->opcode());
-  DCHECK_EQ(IrOpcode::kTypedStateValues, state->InputAt(2)->opcode());
+  DCHECK_EQ(kFrameStateInputCount, state->InputCount());
+  DCHECK_EQ(IrOpcode::kTypedStateValues,
+            state->InputAt(kFrameStateParametersInput)->opcode());
+  DCHECK_EQ(IrOpcode::kTypedStateValues,
+            state->InputAt(kFrameStateLocalsInput)->opcode());
+  DCHECK_EQ(IrOpcode::kTypedStateValues,
+            state->InputAt(kFrameStateStackInput)->opcode());
   FrameStateCallInfo state_info = OpParameter<FrameStateCallInfo>(state);
 
-  int parameters =
-      static_cast<int>(StateValuesAccess(state->InputAt(0)).size());
-  int locals = static_cast<int>(StateValuesAccess(state->InputAt(1)).size());
-  int stack = static_cast<int>(StateValuesAccess(state->InputAt(2)).size());
+  int parameters = static_cast<int>(
+      StateValuesAccess(state->InputAt(kFrameStateParametersInput)).size());
+  int locals = static_cast<int>(
+      StateValuesAccess(state->InputAt(kFrameStateLocalsInput)).size());
+  int stack = static_cast<int>(
+      StateValuesAccess(state->InputAt(kFrameStateStackInput)).size());
 
   FrameStateDescriptor* outer_state = NULL;
-  Node* outer_node = state->InputAt(5);
+  Node* outer_node = state->InputAt(kFrameStateOuterStateInput);
   if (outer_node->opcode() == IrOpcode::kFrameState) {
     outer_state = GetFrameStateDescriptor(outer_node);
   }
@@ -1070,14 +1075,15 @@ void InstructionSelector::AddFrameStateInputs(
   DCHECK_EQ(IrOpcode::kFrameState, state->op()->opcode());
 
   if (descriptor->outer_state()) {
-    AddFrameStateInputs(state->InputAt(5), inputs, descriptor->outer_state());
+    AddFrameStateInputs(state->InputAt(kFrameStateOuterStateInput), inputs,
+                        descriptor->outer_state());
   }
 
-  Node* parameters = state->InputAt(0);
-  Node* locals = state->InputAt(1);
-  Node* stack = state->InputAt(2);
-  Node* context = state->InputAt(3);
-  Node* function = state->InputAt(4);
+  Node* parameters = state->InputAt(kFrameStateParametersInput);
+  Node* locals = state->InputAt(kFrameStateLocalsInput);
+  Node* stack = state->InputAt(kFrameStateStackInput);
+  Node* context = state->InputAt(kFrameStateContextInput);
+  Node* function = state->InputAt(kFrameStateFunctionInput);
 
   DCHECK_EQ(IrOpcode::kTypedStateValues, parameters->op()->opcode());
   DCHECK_EQ(IrOpcode::kTypedStateValues, locals->op()->opcode());

src/compiler/js-typed-lowering.cc

@@ -264,10 +264,13 @@ class JSBinopReduction final {
         state_info.type(), state_info.bailout_id(),
         OutputFrameStateCombine::PokeAt(1));
 
-    return graph()->NewNode(op, frame_state->InputAt(0),
-                            frame_state->InputAt(1), frame_state->InputAt(2),
-                            frame_state->InputAt(3), frame_state->InputAt(4),
-                            frame_state->InputAt(5));
+    return graph()->NewNode(op,
+                            frame_state->InputAt(kFrameStateParametersInput),
+                            frame_state->InputAt(kFrameStateLocalsInput),
+                            frame_state->InputAt(kFrameStateStackInput),
+                            frame_state->InputAt(kFrameStateContextInput),
+                            frame_state->InputAt(kFrameStateFunctionInput),
+                            frame_state->InputAt(kFrameStateOuterStateInput));
   }
 
   Node* CreateFrameStateForRightInput(Node* frame_state, Node* converted_left) {
@@ -302,10 +305,12 @@ class JSBinopReduction final {
     Node* new_stack =
         graph()->NewNode(stack->op(), stack->InputCount(), &new_values.front());
 
-    return graph()->NewNode(op, frame_state->InputAt(0),
-                            frame_state->InputAt(1), new_stack,
-                            frame_state->InputAt(3), frame_state->InputAt(4),
-                            frame_state->InputAt(5));
+    return graph()->NewNode(
+        op, frame_state->InputAt(kFrameStateParametersInput),
+        frame_state->InputAt(kFrameStateLocalsInput), new_stack,
+        frame_state->InputAt(kFrameStateContextInput),
+        frame_state->InputAt(kFrameStateFunctionInput),
+        frame_state->InputAt(kFrameStateOuterStateInput));
   }
 
   Node* ConvertPlainPrimitiveToNumber(Node* node) {