[turbofan] Introduce PretenureFlagOf helper function.

R=jarin@chromium.org

Review-Url: https://codereview.chromium.org/2357573002
Cr-Commit-Position: refs/heads/master@{#39539}

src/compiler/memory-optimizer.cc

@@ -107,7 +107,7 @@ void MemoryOptimizer::VisitAllocate(Node* node, AllocationState const* state) {
   Node* size = node->InputAt(0);
   Node* effect = node->InputAt(1);
   Node* control = node->InputAt(2);
-  PretenureFlag pretenure = OpParameter<PretenureFlag>(node->op());
+  PretenureFlag pretenure = PretenureFlagOf(node->op());
 
   // Propagate tenuring from outer allocations to inner allocations, i.e.
   // when we allocate an object in old space and store a newly allocated
@@ -119,7 +119,7 @@ void MemoryOptimizer::VisitAllocate(Node* node, AllocationState const* state) {
       if (user->opcode() == IrOpcode::kStoreField && edge.index() == 0) {
         Node* const child = user->InputAt(1);
         if (child->opcode() == IrOpcode::kAllocate &&
-            OpParameter<PretenureFlag>(child) == NOT_TENURED) {
+            PretenureFlagOf(child->op()) == NOT_TENURED) {
           NodeProperties::ChangeOp(child, node->op());
           break;
         }
@@ -132,7 +132,7 @@ void MemoryOptimizer::VisitAllocate(Node* node, AllocationState const* state) {
       if (user->opcode() == IrOpcode::kStoreField && edge.index() == 1) {
         Node* const parent = user->InputAt(0);
         if (parent->opcode() == IrOpcode::kAllocate &&
-            OpParameter<PretenureFlag>(parent) == TENURED) {
+            PretenureFlagOf(parent->op()) == TENURED) {
           pretenure = TENURED;
           break;
         }

src/compiler/simplified-operator.cc

@@ -332,6 +332,11 @@ NumberOperationHint NumberOperationHintOf(const Operator* op) {
   return OpParameter<NumberOperationHint>(op);
 }
 
+PretenureFlag PretenureFlagOf(const Operator* op) {
+  DCHECK_EQ(IrOpcode::kAllocate, op->opcode());
+  return OpParameter<PretenureFlag>(op);
+}
+
 #define PURE_OP_LIST(V)                                          \
   V(BooleanNot, Operator::kNoProperties, 1, 0)                   \
   V(NumberEqual, Operator::kCommutative, 2, 0)                   \

src/compiler/simplified-operator.h

@@ -183,6 +183,8 @@ std::ostream& operator<<(std::ostream&, NumberOperationHint);
 NumberOperationHint NumberOperationHintOf(const Operator* op)
     WARN_UNUSED_RESULT;
 
+PretenureFlag PretenureFlagOf(const Operator* op) WARN_UNUSED_RESULT;
+
 // Interface for building simplified operators, which represent the
 // medium-level operations of V8, including adding numbers, allocating objects,
 // indexing into objects and arrays, etc.