1 files changed, 73 insertions, 7 deletions

diff --git a/deps/v8/src/compiler/greedy-allocator.h b/deps/v8/src/compiler/greedy-allocator.h
index c4e330eb97..45bbd87da8 100644
--- a/deps/v8/src/compiler/greedy-allocator.h
+++ b/deps/v8/src/compiler/greedy-allocator.h
@@ -18,21 +18,45 @@ namespace compiler {
 // we may extend this to groups of LiveRanges. It has to be comparable.
 class AllocationCandidate {
  public:
-  explicit AllocationCandidate(LiveRange* range) : range_(range) {}
+  explicit AllocationCandidate(LiveRange* range)
+      : is_group_(false), size_(range->GetSize()) {
+    candidate_.range_ = range;
+  }
+
+  explicit AllocationCandidate(LiveRangeGroup* ranges)
+      : is_group_(true), size_(CalculateGroupSize(ranges)) {
+    candidate_.group_ = ranges;
+  }
 
   // Strict ordering operators
   bool operator<(const AllocationCandidate& other) const {
-    return range_->GetSize() < other.range_->GetSize();
+    return size() < other.size();
   }
 
   bool operator>(const AllocationCandidate& other) const {
-    return range_->GetSize() > other.range_->GetSize();
+    return size() > other.size();
   }
 
-  LiveRange* live_range() const { return range_; }
+  bool is_group() const { return is_group_; }
+  LiveRange* live_range() const { return candidate_.range_; }
+  LiveRangeGroup* group() const { return candidate_.group_; }
 
  private:
-  LiveRange* range_;
+  unsigned CalculateGroupSize(LiveRangeGroup* group) {
+    unsigned ret = 0;
+    for (LiveRange* range : group->ranges()) {
+      ret += range->GetSize();
+    }
+    return ret;
+  }
+
+  unsigned size() const { return size_; }
+  bool is_group_;
+  unsigned size_;
+  union {
+    LiveRange* range_;
+    LiveRangeGroup* group_;
+  } candidate_;
 };
 
 
@@ -41,6 +65,7 @@ class AllocationScheduler final : ZoneObject {
  public:
   explicit AllocationScheduler(Zone* zone) : queue_(zone) {}
   void Schedule(LiveRange* range);
+  void Schedule(LiveRangeGroup* group);
   AllocationCandidate GetNext();
   bool empty() const { return queue_.empty(); }
 
@@ -85,12 +110,15 @@ class GreedyAllocator final : public RegisterAllocator {
   }
 
   Zone* local_zone() const { return local_zone_; }
+  ZoneVector<LiveRangeGroup*>& groups() { return groups_; }
+  const ZoneVector<LiveRangeGroup*>& groups() const { return groups_; }
 
   // Insert fixed ranges.
   void PreallocateFixedRanges();
 
+  void GroupLiveRanges();
+
   // Schedule unassigned live ranges for allocation.
-  // TODO(mtrofin): groups.
   void ScheduleAllocationCandidates();
 
   void AllocateRegisterToRange(unsigned reg_id, LiveRange* range) {
@@ -106,6 +134,7 @@ class GreedyAllocator final : public RegisterAllocator {
 
   void TryAllocateCandidate(const AllocationCandidate& candidate);
   void TryAllocateLiveRange(LiveRange* range);
+  void TryAllocateGroup(LiveRangeGroup* group);
 
   bool CanProcessRange(LiveRange* range) const {
     return range != nullptr && !range->IsEmpty() && range->kind() == mode();
@@ -119,12 +148,47 @@ class GreedyAllocator final : public RegisterAllocator {
 
   // Returns kInvalidWeight if there are no conflicts, or the largest weight of
   // a range conflicting with the given range, at the given register.
+  float GetMaximumConflictingWeight(unsigned reg_id, const LiveRange* range,
+                                    float competing_weight) const;
+
+  // Returns kInvalidWeight if there are no conflicts, or the largest weight of
+  // a range conflicting with the given range, at the given register.
   float GetMaximumConflictingWeight(unsigned reg_id,
-                                    const LiveRange* range) const;
+                                    const LiveRangeGroup* group,
+                                    float group_weight) const;
 
   // This is the extension point for splitting heuristics.
   void SplitOrSpillBlockedRange(LiveRange* range);
 
+  // Find a good position where to fill, after a range was spilled after a call.
+  LifetimePosition FindSplitPositionAfterCall(const LiveRange* range,
+                                              int call_index);
+  // Split a range around all calls it passes over. Returns true if any changes
+  // were made, or false if no calls were found.
+  bool TrySplitAroundCalls(LiveRange* range);
+
+  // Find a split position at the outmost loop.
+  LifetimePosition FindSplitPositionBeforeLoops(LiveRange* range);
+
+  // Finds the first call instruction in the path of this range. Splits before
+  // and requeues that segment (if any), spills the section over the call, and
+  // returns the section after the call. The return is:
+  // - same range, if no call was found
+  // - nullptr, if the range finished at the call and there's no "after the
+  //   call" portion.
+  // - the portion after the call.
+  LiveRange* GetRemainderAfterSplittingAroundFirstCall(LiveRange* range);
+
+  // While we attempt to merge spill ranges later on in the allocation pipeline,
+  // we want to ensure group elements get merged. Waiting until later may hinder
+  // merge-ability, since the pipeline merger (being naive) may create conflicts
+  // between spill ranges of group members.
+  void TryReuseSpillRangesForGroups();
+
+  LifetimePosition GetLastResortSplitPosition(const LiveRange* range);
+
+  bool IsProgressPossible(const LiveRange* range);
+
   // Necessary heuristic: spill when all else failed.
   void SpillRangeAsLastResort(LiveRange* range);
 
@@ -133,6 +197,8 @@ class GreedyAllocator final : public RegisterAllocator {
   Zone* local_zone_;
   ZoneVector<CoalescedLiveRanges*> allocations_;
   AllocationScheduler scheduler_;
+  ZoneVector<LiveRangeGroup*> groups_;
+
   DISALLOW_COPY_AND_ASSIGN(GreedyAllocator);
 };
 }  // namespace compiler