Synchronize with r15701.

src/hydrogen-minus-zero.h

Index: src/hydrogen-minus-zero.h
diff --git a/src/hydrogen-sce.h b/src/hydrogen-minus-zero.h
similarity index 78%
copy from src/hydrogen-sce.h
copy to src/hydrogen-minus-zero.h
index 55e153e0ed5ee3481669ee5c991f81238d51176e..d23ec1196b3419cdc06e20aa3e12688979306009 100644
--- a/src/hydrogen-sce.h
+++ b/src/hydrogen-minus-zero.h
@@ -25,8 +25,8 @@
 // (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
 // OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 
-#ifndef V8_HYDROGEN_SCE_H_
-#define V8_HYDROGEN_SCE_H_
+#ifndef V8_HYDROGEN_MINUS_ZERO_H_
+#define V8_HYDROGEN_MINUS_ZERO_H_
 
 #include "hydrogen.h"
 
@@ -34,15 +34,23 @@ namespace v8 {
 namespace internal {
 
 
-class HStackCheckEliminationPhase : public HPhase {
+class HComputeMinusZeroChecksPhase : public HPhase {
  public:
-  explicit HStackCheckEliminationPhase(HGraph* graph)
-      : HPhase("H_Stack check elimination", graph) { }
+  explicit HComputeMinusZeroChecksPhase(HGraph* graph)
+      : HPhase("H_Compute minus zero checks", graph),
+        visited_(graph->GetMaximumValueID(), zone()) { }
 
   void Run();
+
+ private:
+  void PropagateMinusZeroChecks(HValue* value);
+
+  BitVector visited_;
+
+  DISALLOW_COPY_AND_ASSIGN(HComputeMinusZeroChecksPhase);
 };
 
 
 } }  // namespace v8::internal
 
-#endif  // V8_HYDROGEN_SCE_H_
+#endif  // V8_HYDROGEN_MINUS_ZERO_H_