Linear scan: split at better positions.

- Split at block entry to piggy back on control flow resolution.
- Split at the loop header, if the split position is within a loop.

Change-Id: I718299a58c02ee02a1b22bda589607c69a35f0e8

1 files changed, 6 insertions, 2 deletions

diff --git a/compiler/optimizing/register_allocator.h b/compiler/optimizing/register_allocator.h
index 717be75533..dc9c708eea 100644
--- a/compiler/optimizing/register_allocator.h
+++ b/compiler/optimizing/register_allocator.h
@@ -86,8 +86,12 @@ class RegisterAllocator {
   // Add `interval` in the given sorted list.
   static void AddSorted(GrowableArray<LiveInterval*>* array, LiveInterval* interval);
 
-  // Split `interval` at the position `at`. The new interval starts at `at`.
-  LiveInterval* Split(LiveInterval* interval, size_t at);
+  // Split `interval` at the position `position`. The new interval starts at `position`.
+  LiveInterval* Split(LiveInterval* interval, size_t position);
+
+  // Split `interval` at a position between `from` and `to`. The method will try
+  // to find an optimal split position.
+  LiveInterval* SplitBetween(LiveInterval* interval, size_t from, size_t to);
 
   // Returns whether `reg` is blocked by the code generator.
   bool IsBlocked(int reg) const;