Fix a bug in the register allocator.

When allocating a register blocked by existing intervals,
we need to split inactive intervals at the end of their
lifetime hole, and not at the next intersection. Otherwise,
the allocation for following intervals will not see
that a register is being used by the split interval.

Change-Id: I40cc79dde541c07392a7cf4c6f0b291dd1ce1819

1 files changed, 6 insertions, 2 deletions

diff --git a/compiler/optimizing/optimizing_unit_test.h b/compiler/optimizing/optimizing_unit_test.h
index 04b56345c4..b3eb1e2d51 100644
--- a/compiler/optimizing/optimizing_unit_test.h
+++ b/compiler/optimizing/optimizing_unit_test.h
@@ -45,8 +45,12 @@ namespace art {
 LiveInterval* BuildInterval(const size_t ranges[][2],
                             size_t number_of_ranges,
                             ArenaAllocator* allocator,
-                            int reg = -1) {
-  LiveInterval* interval = LiveInterval::MakeInterval(allocator, Primitive::kPrimInt);
+                            int reg = -1,
+                            HInstruction* defined_by = nullptr) {
+  LiveInterval* interval = LiveInterval::MakeInterval(allocator, Primitive::kPrimInt, defined_by);
+  if (defined_by != nullptr) {
+    defined_by->SetLiveInterval(interval);
+  }
   for (size_t i = number_of_ranges; i > 0; --i) {
     interval->AddRange(ranges[i - 1][0], ranges[i - 1][1]);
   }