[cleanup] Introduce IsMarked() predicate to ScheduleLateNodeVisitor

R=jarin@chromium.org

Change-Id: Ia585398db7e9c69283450def924bc10edc37448f
Reviewed-on: https://chromium-review.googlesource.com/c/1335563Reviewed-by: Jaroslav Sevcik <jarin@chromium.org>
Commit-Queue: Michael Stanton <mvstanton@chromium.org>
Cr-Commit-Position: refs/heads/master@{#57522}

src/compiler/scheduler.cc

@@ -1443,13 +1443,19 @@ class ScheduleLateNodeVisitor {
     }
   }
 
+  bool IsMarked(BasicBlock* block) const {
+    DCHECK_LT(block->id().ToSize(), marked_.size());
+    return marked_[block->id().ToSize()];
+  }
+
+  void Mark(BasicBlock* block) { marked_[block->id().ToSize()] = true; }
+
   // Mark {block} and push its non-marked predecessor on the marking queue.
   void MarkBlock(BasicBlock* block) {
     DCHECK_LT(block->id().ToSize(), marked_.size());
-    marked_[block->id().ToSize()] = true;
+    Mark(block);
     for (BasicBlock* pred_block : block->predecessors()) {
-      DCHECK_LT(pred_block->id().ToSize(), marked_.size());
-      if (marked_[pred_block->id().ToSize()]) continue;
+      if (IsMarked(pred_block)) continue;
       marking_queue_.push_back(pred_block);
     }
   }
@@ -1474,7 +1480,7 @@ class ScheduleLateNodeVisitor {
     for (Edge edge : node->use_edges()) {
       if (!scheduler_->IsLive(edge.from())) continue;
       BasicBlock* use_block = GetBlockForUse(edge);
-      if (use_block == nullptr || marked_[use_block->id().ToSize()]) continue;
+      if (use_block == nullptr || IsMarked(use_block)) continue;
       if (use_block == block) {
         TRACE("  not splitting #%d:%s, it is used in id:%d\n", node->id(),
               node->op()->mnemonic(), block->id().ToInt());
@@ -1489,10 +1495,10 @@ class ScheduleLateNodeVisitor {
     do {
       BasicBlock* top_block = marking_queue_.front();
       marking_queue_.pop_front();
-      if (marked_[top_block->id().ToSize()]) continue;
+      if (IsMarked(top_block)) continue;
       bool marked = true;
       for (BasicBlock* successor : top_block->successors()) {
-        if (!marked_[successor->id().ToSize()]) {
+        if (!IsMarked(successor)) {
           marked = false;
           break;
         }
@@ -1503,7 +1509,7 @@ class ScheduleLateNodeVisitor {
     // If the (common dominator) {block} is marked, we know that all paths from
     // {block} to the end contain at least one use of {node}, and hence there's
     // no point in splitting the {node} in this case.
-    if (marked_[block->id().ToSize()]) {
+    if (IsMarked(block)) {
       TRACE("  not splitting #%d:%s, its common dominator id:%d is perfect\n",
             node->id(), node->op()->mnemonic(), block->id().ToInt());
       return block;
@@ -1518,7 +1524,7 @@ class ScheduleLateNodeVisitor {
       if (!scheduler_->IsLive(edge.from())) continue;
       BasicBlock* use_block = GetBlockForUse(edge);
       if (use_block == nullptr) continue;
-      while (marked_[use_block->dominator()->id().ToSize()]) {
+      while (IsMarked(use_block)) {
         use_block = use_block->dominator();
       }
       auto& use_node = dominators[use_block];