[turbofan] Move GetCommonDominator to BasicBlock.

src/compiler/schedule.cc

 // Copyright 2013 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.
 
 #include "src/compiler/schedule.h"
 
 #include "src/compiler/node.h"
 #include "src/compiler/node-properties.h"
 #include "src/compiler/node-properties-inl.h"
 #include "src/ostreams.h"
 
 namespace v8 {
 namespace internal {
 namespace compiler {
 
 BasicBlock::BasicBlock(Zone* zone, Id id)
     : loop_number_(-1),
       rpo_number_(-1),
       deferred_(false),
       dominator_depth_(-1),
-      dominator_(NULL),
-      rpo_next_(NULL),
-      loop_header_(NULL),
-      loop_end_(NULL),
+      dominator_(nullptr),
+      rpo_next_(nullptr),
+      loop_header_(nullptr),
+      loop_end_(nullptr),
       loop_depth_(0),
       control_(kNone),
-      control_input_(NULL),
+      control_input_(nullptr),
       nodes_(zone),
       successors_(zone),
       predecessors_(zone),
       id_(id) {}
 
 
 bool BasicBlock::LoopContains(BasicBlock* block) const {
   // RPO numbers must be initialized.
   DCHECK(rpo_number_ >= 0);
   DCHECK(block->rpo_number_ >= 0);
@@ skipping 37 matching lines @@
 
 
 void BasicBlock::set_loop_end(BasicBlock* loop_end) { loop_end_ = loop_end; }
 
 
 void BasicBlock::set_loop_header(BasicBlock* loop_header) {
   loop_header_ = loop_header;
 }
 
 
+// static
+BasicBlock* BasicBlock::GetCommonDominator(BasicBlock* b1, BasicBlock* b2) {
+  while (b1 != b2) {
+    if (b1->dominator_depth() < b2->dominator_depth()) {
+      b2 = b2->dominator();
+    } else {
+      b1 = b1->dominator();
+    }
+  }
+  return b1;
+}
+
+
 std::ostream& operator<<(std::ostream& os, const BasicBlock::Control& c) {
   switch (c) {
     case BasicBlock::kNone:
       return os << "none";
     case BasicBlock::kGoto:
       return os << "goto";
     case BasicBlock::kBranch:
       return os << "branch";
     case BasicBlock::kReturn:
       return os << "return";
@@ skipping 208 matching lines @@
       }
       os << "\n";
     }
   }
   return os;
 }
 
 }  // namespace compiler
 }  // namespace internal
 }  // namespace v8