commit 4e92c3ce7ef354620a785553bbada554fca83a67
author Nicolas Geoffray <ngeoffray@google.com> Mon May 08 09:34:26 2017 +0100
committer Nicolas Geoffray <ngeoffray@google.com> Wed May 10 09:27:33 2017 +0100
tree 42029deff4d3ba7f89b5fdbf79ff410da575f431
parent 549844e9ccf432d1396b19af890eedb602b8ba04

Add runtime reasons for deopt.

Currently to help investigate. Also:
1) Log when deoptimization happens (which method and what reason)
2) Trace when deoptimization happens (to make it visible in systrace)

bug:37655083
Test: test-art-host test-art-target
Change-Id: I0c2d87b40db09e8e475cf97a7c784a034c585e97

compiler/optimizing/bounds_check_elimination.cc

diff --git a/compiler/optimizing/bounds_check_elimination.cc b/compiler/optimizing/bounds_check_elimination.cc
index d38d5f8..ed630cd 100644
--- a/compiler/optimizing/bounds_check_elimination.cc
+++ b/compiler/optimizing/bounds_check_elimination.cc
@@ -1550,7 +1550,7 @@
         HBasicBlock* block = GetPreHeader(loop, check);
         HInstruction* cond =
             new (GetGraph()->GetArena()) HEqual(array, GetGraph()->GetNullConstant());
-        InsertDeoptInLoop(loop, block, cond);
+        InsertDeoptInLoop(loop, block, cond, /* is_null_check */ true);
         ReplaceInstruction(check, array);
         return true;
       }
@@ -1616,11 +1616,16 @@
   }
 
   /** Inserts a deoptimization test in a loop preheader. */
-  void InsertDeoptInLoop(HLoopInformation* loop, HBasicBlock* block, HInstruction* condition) {
+  void InsertDeoptInLoop(HLoopInformation* loop,
+                         HBasicBlock* block,
+                         HInstruction* condition,
+                         bool is_null_check = false) {
     HInstruction* suspend = loop->GetSuspendCheck();
     block->InsertInstructionBefore(condition, block->GetLastInstruction());
+    DeoptimizationKind kind =
+        is_null_check ? DeoptimizationKind::kLoopNullBCE : DeoptimizationKind::kLoopBoundsBCE;
     HDeoptimize* deoptimize = new (GetGraph()->GetArena()) HDeoptimize(
-        GetGraph()->GetArena(), condition, HDeoptimize::Kind::kBCE, suspend->GetDexPc());
+        GetGraph()->GetArena(), condition, kind, suspend->GetDexPc());
     block->InsertInstructionBefore(deoptimize, block->GetLastInstruction());
     if (suspend->HasEnvironment()) {
       deoptimize->CopyEnvironmentFromWithLoopPhiAdjustment(
@@ -1633,7 +1638,7 @@
     HBasicBlock* block = bounds_check->GetBlock();
     block->InsertInstructionBefore(condition, bounds_check);
     HDeoptimize* deoptimize = new (GetGraph()->GetArena()) HDeoptimize(
-        GetGraph()->GetArena(), condition, HDeoptimize::Kind::kBCE, bounds_check->GetDexPc());
+        GetGraph()->GetArena(), condition, DeoptimizationKind::kBlockBCE, bounds_check->GetDexPc());
     block->InsertInstructionBefore(deoptimize, bounds_check);
     deoptimize->CopyEnvironmentFrom(bounds_check->GetEnvironment());
   }