Merge "Use implicit null checks inside try blocks."

1 files changed, 25 insertions, 13 deletions

diff --git a/compiler/optimizing/code_generator.cc b/compiler/optimizing/code_generator.cc
index 2087888f4e..ac7d5fe427 100644
--- a/compiler/optimizing/code_generator.cc
+++ b/compiler/optimizing/code_generator.cc
@@ -1081,13 +1081,6 @@ void CodeGenerator::EmitEnvironment(HEnvironment* environment, SlowPathCode* slo
   }
 }
 
-bool CodeGenerator::IsImplicitNullCheckAllowed(HNullCheck* null_check) const {
-  return compiler_options_.GetImplicitNullChecks() &&
-         // Null checks which might throw into a catch block need to save live
-         // registers and therefore cannot be done implicitly.
-         !null_check->CanThrowIntoCatchBlock();
-}
-
 bool CodeGenerator::CanMoveNullCheckToUser(HNullCheck* null_check) {
   HInstruction* first_next_not_move = null_check->GetNextDisregardingMoves();
 
@@ -1096,6 +1089,10 @@ bool CodeGenerator::CanMoveNullCheckToUser(HNullCheck* null_check) {
 }
 
 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.
@@ -1114,16 +1111,31 @@ void CodeGenerator::MaybeRecordImplicitNullCheck(HInstruction* instr) {
   // 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();
-    if (IsImplicitNullCheckAllowed(null_check)) {
-      // 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.
-      RecordPcInfo(null_check, null_check->GetDexPc());
-    }
+    // 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.
+    RecordPcInfo(null_check, null_check->GetDexPc());
   }
 }
 
+LocationSummary* CodeGenerator::CreateNullCheckLocations(HNullCheck* null_check) {
+  // Note: Using kNoCall allows the method to be treated as leaf (and eliminate the
+  // HSuspendCheck from entry block). However, it will still get a valid stack frame
+  // because the HNullCheck needs an environment.
+  LocationSummary::CallKind call_kind = LocationSummary::kNoCall;
+  // When throwing from a try block, we may need to retrieve dalvik registers from
+  // physical registers. For implicit null checks, this is done by using kSaveEverything
+  // runtime method but for explicit null checks we need to save live registers.
+  if (!compiler_options_.GetImplicitNullChecks() && null_check->CanThrowIntoCatchBlock()) {
+    call_kind = LocationSummary::kCallOnSlowPath;
+  }
+  LocationSummary* locations = new (GetGraph()->GetArena()) LocationSummary(null_check, call_kind);
+  locations->SetInAt(0, Location::RequiresRegister());
+  DCHECK(!null_check->HasUses());
+  return locations;
+}
+
 void CodeGenerator::GenerateNullCheck(HNullCheck* instruction) {
-  if (IsImplicitNullCheckAllowed(instruction)) {
+  if (compiler_options_.GetImplicitNullChecks()) {
     MaybeRecordStat(kImplicitNullCheckGenerated);
     GenerateImplicitNullCheck(instruction);
   } else {