[turbofan] Greedy: small fix in groupping algo.

src/compiler/greedy-allocator.cc

 // Copyright 2015 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/greedy-allocator.h"
 #include "src/compiler/register-allocator.h"
 
 namespace v8 {
 namespace internal {
 namespace compiler {
@@ skipping 160 matching lines @@
       EnsureValidRangeWeight(fixed_range);
       AllocateRegisterToRange(reg_nr, fixed_range);
     }
   }
 }
 
 
 void GreedyAllocator::GroupLiveRanges() {
   CoalescedLiveRanges groupper(local_zone());
   for (TopLevelLiveRange* range : data()->live_ranges()) {
+    groupper.clear();

[Jarin, 2015/09/16 21:28:00]

nit: groupper should be with single p.

     // Skip splinters, because we do not want to optimize for them, and moves
     // due to assigning them to different registers occur in deferred blocks.
     if (!CanProcessRange(range) || range->IsSplinter() || !range->is_phi()) {
       continue;
     }
 
     // A phi can't be a memory operand, so it couldn't have been split.
     DCHECK(!range->spilled());
 
     // Maybe this phi range is itself an input to another phi which was already
     // processed.
     LiveRangeGroup* latest_grp = range->group() != nullptr
                                      ? range->group()
                                      : new (local_zone())
                                            LiveRangeGroup(local_zone());
 
     // Populate the groupper.
     if (range->group() == nullptr) {
-      groupper.clear();
       groupper.AllocateRange(range);
     } else {
       for (LiveRange* member : range->group()->ranges()) {
         groupper.AllocateRange(member);
       }
     }
     for (int j : data()->GetPhiMapValueFor(range)->phi()->operands()) {
       // skip output also in input, which may happen for loops.
       if (j == range->vreg()) continue;
 
@@ skipping 449 matching lines @@
     scheduler().Schedule(range);
     return;
   }
   SpillRangeAsLastResort(range);
 }
 
 
 }  // namespace compiler
 }  // namespace internal
 }  // namespace v8