Revert "Use implicit null checks inside try blocks."
Fails gcstress tests.
This reverts commit 7aa7560683626c7893011271c241b3265ded1dc3.
Change-Id: I4f5c89048b9ffddbafa02f3001e329ff87058ca2
diff --git a/compiler/optimizing/code_generator.cc b/compiler/optimizing/code_generator.cc
index ac7d5fe..2087888 100644
--- a/compiler/optimizing/code_generator.cc
+++ b/compiler/optimizing/code_generator.cc
@@ -1081,6 +1081,13 @@
}
}
+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();
@@ -1089,10 +1096,6 @@
}
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.
@@ -1111,31 +1114,16 @@
// 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.
- RecordPcInfo(null_check, null_check->GetDexPc());
+ 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());
+ }
}
}
-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 (compiler_options_.GetImplicitNullChecks()) {
+ if (IsImplicitNullCheckAllowed(instruction)) {
MaybeRecordStat(kImplicitNullCheckGenerated);
GenerateImplicitNullCheck(instruction);
} else {
diff --git a/compiler/optimizing/code_generator.h b/compiler/optimizing/code_generator.h
index b4d4b9b..0c60a98 100644
--- a/compiler/optimizing/code_generator.h
+++ b/compiler/optimizing/code_generator.h
@@ -313,7 +313,6 @@
bool CanMoveNullCheckToUser(HNullCheck* null_check);
void MaybeRecordImplicitNullCheck(HInstruction* instruction);
- LocationSummary* CreateNullCheckLocations(HNullCheck* null_check);
void GenerateNullCheck(HNullCheck* null_check);
virtual void GenerateImplicitNullCheck(HNullCheck* null_check) = 0;
virtual void GenerateExplicitNullCheck(HNullCheck* null_check) = 0;
@@ -323,6 +322,12 @@
// TODO: Replace with a catch-entering instruction that records the environment.
void RecordCatchBlockInfo();
+ // Returns true if implicit null checks are allowed in the compiler options
+ // and if the null check is not inside a try block. We currently cannot do
+ // implicit null checks in that case because we need the NullCheckSlowPath to
+ // save live registers, which may be needed by the runtime to set catch phis.
+ bool IsImplicitNullCheckAllowed(HNullCheck* null_check) const;
+
// TODO: Avoid creating the `std::unique_ptr` here.
void AddSlowPath(SlowPathCode* slow_path) {
slow_paths_.push_back(std::unique_ptr<SlowPathCode>(slow_path));
@@ -708,8 +713,6 @@
bool is_leaf_;
// Whether an instruction in the graph accesses the current method.
- // TODO: Rename: this actually indicates that some instruction in the method
- // needs the environment including a valid stack frame.
bool requires_current_method_;
friend class OptimizingCFITest;
diff --git a/compiler/optimizing/code_generator_arm.cc b/compiler/optimizing/code_generator_arm.cc
index 4f80931..5301a6b 100644
--- a/compiler/optimizing/code_generator_arm.cc
+++ b/compiler/optimizing/code_generator_arm.cc
@@ -4251,7 +4251,14 @@
}
void LocationsBuilderARM::VisitNullCheck(HNullCheck* instruction) {
- codegen_->CreateNullCheckLocations(instruction);
+ LocationSummary::CallKind call_kind = instruction->CanThrowIntoCatchBlock()
+ ? LocationSummary::kCallOnSlowPath
+ : LocationSummary::kNoCall;
+ LocationSummary* locations = new (GetGraph()->GetArena()) LocationSummary(instruction, call_kind);
+ locations->SetInAt(0, Location::RequiresRegister());
+ if (instruction->HasUses()) {
+ locations->SetOut(Location::SameAsFirstInput());
+ }
}
void CodeGeneratorARM::GenerateImplicitNullCheck(HNullCheck* instruction) {
diff --git a/compiler/optimizing/code_generator_arm64.cc b/compiler/optimizing/code_generator_arm64.cc
index 09808bb..36f7b4d 100644
--- a/compiler/optimizing/code_generator_arm64.cc
+++ b/compiler/optimizing/code_generator_arm64.cc
@@ -4539,7 +4539,14 @@
}
void LocationsBuilderARM64::VisitNullCheck(HNullCheck* instruction) {
- codegen_->CreateNullCheckLocations(instruction);
+ LocationSummary::CallKind call_kind = instruction->CanThrowIntoCatchBlock()
+ ? LocationSummary::kCallOnSlowPath
+ : LocationSummary::kNoCall;
+ LocationSummary* locations = new (GetGraph()->GetArena()) LocationSummary(instruction, call_kind);
+ locations->SetInAt(0, Location::RequiresRegister());
+ if (instruction->HasUses()) {
+ locations->SetOut(Location::SameAsFirstInput());
+ }
}
void CodeGeneratorARM64::GenerateImplicitNullCheck(HNullCheck* instruction) {
diff --git a/compiler/optimizing/code_generator_mips.cc b/compiler/optimizing/code_generator_mips.cc
index 9abe485..92e9cd9 100644
--- a/compiler/optimizing/code_generator_mips.cc
+++ b/compiler/optimizing/code_generator_mips.cc
@@ -4856,7 +4856,14 @@
}
void LocationsBuilderMIPS::VisitNullCheck(HNullCheck* instruction) {
- codegen_->CreateNullCheckLocations(instruction);
+ LocationSummary::CallKind call_kind = instruction->CanThrowIntoCatchBlock()
+ ? LocationSummary::kCallOnSlowPath
+ : LocationSummary::kNoCall;
+ LocationSummary* locations = new (GetGraph()->GetArena()) LocationSummary(instruction, call_kind);
+ locations->SetInAt(0, Location::RequiresRegister());
+ if (instruction->HasUses()) {
+ locations->SetOut(Location::SameAsFirstInput());
+ }
}
void CodeGeneratorMIPS::GenerateImplicitNullCheck(HNullCheck* instruction) {
diff --git a/compiler/optimizing/code_generator_mips64.cc b/compiler/optimizing/code_generator_mips64.cc
index 4d87523..664d498 100644
--- a/compiler/optimizing/code_generator_mips64.cc
+++ b/compiler/optimizing/code_generator_mips64.cc
@@ -3461,7 +3461,14 @@
}
void LocationsBuilderMIPS64::VisitNullCheck(HNullCheck* instruction) {
- codegen_->CreateNullCheckLocations(instruction);
+ LocationSummary::CallKind call_kind = instruction->CanThrowIntoCatchBlock()
+ ? LocationSummary::kCallOnSlowPath
+ : LocationSummary::kNoCall;
+ LocationSummary* locations = new (GetGraph()->GetArena()) LocationSummary(instruction, call_kind);
+ locations->SetInAt(0, Location::RequiresRegister());
+ if (instruction->HasUses()) {
+ locations->SetOut(Location::SameAsFirstInput());
+ }
}
void CodeGeneratorMIPS64::GenerateImplicitNullCheck(HNullCheck* instruction) {
diff --git a/compiler/optimizing/code_generator_x86.cc b/compiler/optimizing/code_generator_x86.cc
index bf96be2..4689ccb 100644
--- a/compiler/optimizing/code_generator_x86.cc
+++ b/compiler/optimizing/code_generator_x86.cc
@@ -4979,10 +4979,16 @@
}
void LocationsBuilderX86::VisitNullCheck(HNullCheck* instruction) {
- LocationSummary* locations = codegen_->CreateNullCheckLocations(instruction);
- if (!codegen_->GetCompilerOptions().GetImplicitNullChecks()) {
- // Explicit null checks can use any location.
- locations->SetInAt(0, Location::Any());
+ LocationSummary::CallKind call_kind = instruction->CanThrowIntoCatchBlock()
+ ? LocationSummary::kCallOnSlowPath
+ : LocationSummary::kNoCall;
+ LocationSummary* locations = new (GetGraph()->GetArena()) LocationSummary(instruction, call_kind);
+ Location loc = codegen_->IsImplicitNullCheckAllowed(instruction)
+ ? Location::RequiresRegister()
+ : Location::Any();
+ locations->SetInAt(0, loc);
+ if (instruction->HasUses()) {
+ locations->SetOut(Location::SameAsFirstInput());
}
}
diff --git a/compiler/optimizing/code_generator_x86_64.cc b/compiler/optimizing/code_generator_x86_64.cc
index d569f1f..a21a09e 100644
--- a/compiler/optimizing/code_generator_x86_64.cc
+++ b/compiler/optimizing/code_generator_x86_64.cc
@@ -4490,10 +4490,16 @@
}
void LocationsBuilderX86_64::VisitNullCheck(HNullCheck* instruction) {
- LocationSummary* locations = codegen_->CreateNullCheckLocations(instruction);
- if (!codegen_->GetCompilerOptions().GetImplicitNullChecks()) {
- // Explicit null checks can use any location.
- locations->SetInAt(0, Location::Any());
+ LocationSummary::CallKind call_kind = instruction->CanThrowIntoCatchBlock()
+ ? LocationSummary::kCallOnSlowPath
+ : LocationSummary::kNoCall;
+ LocationSummary* locations = new (GetGraph()->GetArena()) LocationSummary(instruction, call_kind);
+ Location loc = codegen_->IsImplicitNullCheckAllowed(instruction)
+ ? Location::RequiresRegister()
+ : Location::Any();
+ locations->SetInAt(0, loc);
+ if (instruction->HasUses()) {
+ locations->SetOut(Location::SameAsFirstInput());
}
}