Merge "Fix longstanding bug around implicit NPEs and GC, version 2."

1 files changed, 3 insertions, 28 deletions

diff --git a/compiler/optimizing/code_generator.cc b/compiler/optimizing/code_generator.cc
index a13efcaee2..a90ff3f885 100644
--- a/compiler/optimizing/code_generator.cc
+++ b/compiler/optimizing/code_generator.cc
@@ -1394,37 +1394,12 @@ void CodeGenerator::EmitEnvironment(HEnvironment* environment, SlowPathCode* slo
 }
 
 bool CodeGenerator::CanMoveNullCheckToUser(HNullCheck* null_check) {
-  HInstruction* first_next_not_move = null_check->GetNextDisregardingMoves();
-
-  return (first_next_not_move != nullptr)
-      && first_next_not_move->CanDoImplicitNullCheckOn(null_check->InputAt(0));
+  return null_check->IsEmittedAtUseSite();
 }
 
 void CodeGenerator::MaybeRecordImplicitNullCheck(HInstruction* instr) {
-  if (!compiler_options_.GetImplicitNullChecks()) {
-    return;
-  }
-
-  // If we are from a static path don't record the pc as we can't throw NPE.
-  // NB: having the checks here makes the code much less verbose in the arch
-  // specific code generators.
-  if (instr->IsStaticFieldSet() || instr->IsStaticFieldGet()) {
-    return;
-  }
-
-  if (!instr->CanDoImplicitNullCheckOn(instr->InputAt(0))) {
-    return;
-  }
-
-  // Find the first previous instruction which is not a move.
-  HInstruction* first_prev_not_move = instr->GetPreviousDisregardingMoves();
-
-  // If the instruction is a null check it means that `instr` is the first user
-  // and needs to record the pc.
-  if (first_prev_not_move != nullptr && first_prev_not_move->IsNullCheck()) {
-    HNullCheck* null_check = first_prev_not_move->AsNullCheck();
-    // TODO: The parallel moves modify the environment. Their changes need to be
-    // reverted otherwise the stack maps at the throw point will not be correct.
+  HNullCheck* null_check = instr->GetImplicitNullCheck();
+  if (null_check != nullptr) {
     RecordPcInfo(null_check, null_check->GetDexPc());
   }
 }