Quick: Separate null check elimination and type inference.
Change-Id: I4566ae9354c91ca935481cb4f5b729bba05c1592
diff --git a/compiler/dex/bb_optimizations.h b/compiler/dex/bb_optimizations.h
index b2c348b..fce23bc 100644
--- a/compiler/dex/bb_optimizations.h
+++ b/compiler/dex/bb_optimizations.h
@@ -137,20 +137,20 @@
};
/**
- * @class NullCheckEliminationAndTypeInference
- * @brief Null check elimination and type inference.
+ * @class NullCheckElimination
+ * @brief Null check elimination pass.
*/
-class NullCheckEliminationAndTypeInference : public PassME {
+class NullCheckElimination : public PassME {
public:
- NullCheckEliminationAndTypeInference()
- : PassME("NCE_TypeInference", kRepeatingTopologicalSortTraversal, "4_post_nce_cfg") {
+ NullCheckElimination()
+ : PassME("NCE", kRepeatingTopologicalSortTraversal, "3_post_nce_cfg") {
}
- void Start(PassDataHolder* data) const {
+ bool Gate(const PassDataHolder* data) const {
DCHECK(data != nullptr);
- CompilationUnit* c_unit = down_cast<PassMEDataHolder*>(data)->c_unit;
+ CompilationUnit* c_unit = down_cast<const PassMEDataHolder*>(data)->c_unit;
DCHECK(c_unit != nullptr);
- c_unit->mir_graph->EliminateNullChecksAndInferTypesStart();
+ return c_unit->mir_graph->EliminateNullChecksGate();
}
bool Worker(PassDataHolder* data) const {
@@ -160,14 +160,35 @@
DCHECK(c_unit != nullptr);
BasicBlock* bb = pass_me_data_holder->bb;
DCHECK(bb != nullptr);
- return c_unit->mir_graph->EliminateNullChecksAndInferTypes(bb);
+ return c_unit->mir_graph->EliminateNullChecks(bb);
}
void End(PassDataHolder* data) const {
DCHECK(data != nullptr);
CompilationUnit* c_unit = down_cast<PassMEDataHolder*>(data)->c_unit;
DCHECK(c_unit != nullptr);
- c_unit->mir_graph->EliminateNullChecksAndInferTypesEnd();
+ c_unit->mir_graph->EliminateNullChecksEnd();
+ }
+};
+
+/**
+ * @class TypeInference
+ * @brief Type inference pass.
+ */
+class TypeInference : public PassME {
+ public:
+ TypeInference()
+ : PassME("TypeInference", kRepeatingTopologicalSortTraversal, "4_post_type_cfg") {
+ }
+
+ bool Worker(PassDataHolder* data) const {
+ DCHECK(data != nullptr);
+ PassMEDataHolder* pass_me_data_holder = down_cast<PassMEDataHolder*>(data);
+ CompilationUnit* c_unit = pass_me_data_holder->c_unit;
+ DCHECK(c_unit != nullptr);
+ BasicBlock* bb = pass_me_data_holder->bb;
+ DCHECK(bb != nullptr);
+ return c_unit->mir_graph->InferTypes(bb);
}
};
diff --git a/compiler/dex/mir_graph.h b/compiler/dex/mir_graph.h
index fe6fb75..21b6914 100644
--- a/compiler/dex/mir_graph.h
+++ b/compiler/dex/mir_graph.h
@@ -1022,9 +1022,10 @@
int SRegToVReg(int ssa_reg) const;
void VerifyDataflow();
void CheckForDominanceFrontier(BasicBlock* dom_bb, const BasicBlock* succ_bb);
- void EliminateNullChecksAndInferTypesStart();
- bool EliminateNullChecksAndInferTypes(BasicBlock* bb);
- void EliminateNullChecksAndInferTypesEnd();
+ bool EliminateNullChecksGate();
+ bool EliminateNullChecks(BasicBlock* bb);
+ void EliminateNullChecksEnd();
+ bool InferTypes(BasicBlock* bb);
bool EliminateClassInitChecksGate();
bool EliminateClassInitChecks(BasicBlock* bb);
void EliminateClassInitChecksEnd();
diff --git a/compiler/dex/mir_optimization.cc b/compiler/dex/mir_optimization.cc
index 35dae00..bf3d7df 100644
--- a/compiler/dex/mir_optimization.cc
+++ b/compiler/dex/mir_optimization.cc
@@ -819,96 +819,95 @@
}
}
-void MIRGraph::EliminateNullChecksAndInferTypesStart() {
- if ((cu_->disable_opt & (1 << kNullCheckElimination)) == 0) {
- if (kIsDebugBuild) {
- AllNodesIterator iter(this);
- for (BasicBlock* bb = iter.Next(); bb != nullptr; bb = iter.Next()) {
- CHECK(bb->data_flow_info == nullptr || bb->data_flow_info->ending_check_v == nullptr);
- }
- }
-
- DCHECK(temp_scoped_alloc_.get() == nullptr);
- temp_scoped_alloc_.reset(ScopedArenaAllocator::Create(&cu_->arena_stack));
- temp_bit_vector_size_ = GetNumSSARegs();
- temp_bit_vector_ = new (temp_scoped_alloc_.get()) ArenaBitVector(
- temp_scoped_alloc_.get(), temp_bit_vector_size_, false, kBitMapTempSSARegisterV);
+bool MIRGraph::EliminateNullChecksGate() {
+ if ((cu_->disable_opt & (1 << kNullCheckElimination)) != 0 ||
+ (merged_df_flags_ & DF_HAS_NULL_CHKS) == 0) {
+ return false;
}
+
+ if (kIsDebugBuild) {
+ AllNodesIterator iter(this);
+ for (BasicBlock* bb = iter.Next(); bb != nullptr; bb = iter.Next()) {
+ CHECK(bb->data_flow_info == nullptr || bb->data_flow_info->ending_check_v == nullptr);
+ }
+ }
+
+ DCHECK(temp_scoped_alloc_.get() == nullptr);
+ temp_scoped_alloc_.reset(ScopedArenaAllocator::Create(&cu_->arena_stack));
+ temp_bit_vector_size_ = GetNumSSARegs();
+ temp_bit_vector_ = new (temp_scoped_alloc_.get()) ArenaBitVector(
+ temp_scoped_alloc_.get(), temp_bit_vector_size_, false, kBitMapTempSSARegisterV);
+ return true;
}
/*
- * Eliminate unnecessary null checks for a basic block. Also, while we're doing
- * an iterative walk go ahead and perform type and size inference.
+ * Eliminate unnecessary null checks for a basic block.
*/
-bool MIRGraph::EliminateNullChecksAndInferTypes(BasicBlock* bb) {
- if (bb->data_flow_info == NULL) return false;
- bool infer_changed = false;
- bool do_nce = ((cu_->disable_opt & (1 << kNullCheckElimination)) == 0);
+bool MIRGraph::EliminateNullChecks(BasicBlock* bb) {
+ if (bb->data_flow_info == nullptr) return false;
ArenaBitVector* ssa_regs_to_check = temp_bit_vector_;
- if (do_nce) {
- /*
- * Set initial state. Catch blocks don't need any special treatment.
- */
- if (bb->block_type == kEntryBlock) {
- ssa_regs_to_check->ClearAllBits();
- // Assume all ins are objects.
- for (uint16_t in_reg = GetFirstInVR();
- in_reg < GetNumOfCodeVRs(); in_reg++) {
- ssa_regs_to_check->SetBit(in_reg);
- }
- if ((cu_->access_flags & kAccStatic) == 0) {
- // If non-static method, mark "this" as non-null
- int this_reg = GetFirstInVR();
- ssa_regs_to_check->ClearBit(this_reg);
- }
- } else if (bb->predecessors.size() == 1) {
- BasicBlock* pred_bb = GetBasicBlock(bb->predecessors[0]);
- // pred_bb must have already been processed at least once.
- DCHECK(pred_bb->data_flow_info->ending_check_v != nullptr);
- ssa_regs_to_check->Copy(pred_bb->data_flow_info->ending_check_v);
- if (pred_bb->block_type == kDalvikByteCode) {
- // Check to see if predecessor had an explicit null-check.
- MIR* last_insn = pred_bb->last_mir_insn;
- if (last_insn != nullptr) {
- Instruction::Code last_opcode = last_insn->dalvikInsn.opcode;
- if (last_opcode == Instruction::IF_EQZ) {
- if (pred_bb->fall_through == bb->id) {
- // The fall-through of a block following a IF_EQZ, set the vA of the IF_EQZ to show that
- // it can't be null.
- ssa_regs_to_check->ClearBit(last_insn->ssa_rep->uses[0]);
- }
- } else if (last_opcode == Instruction::IF_NEZ) {
- if (pred_bb->taken == bb->id) {
- // The taken block following a IF_NEZ, set the vA of the IF_NEZ to show that it can't be
- // null.
- ssa_regs_to_check->ClearBit(last_insn->ssa_rep->uses[0]);
- }
+ /*
+ * Set initial state. Catch blocks don't need any special treatment.
+ */
+ if (bb->block_type == kEntryBlock) {
+ ssa_regs_to_check->ClearAllBits();
+ // Assume all ins are objects.
+ for (uint16_t in_reg = GetFirstInVR();
+ in_reg < GetNumOfCodeVRs(); in_reg++) {
+ ssa_regs_to_check->SetBit(in_reg);
+ }
+ if ((cu_->access_flags & kAccStatic) == 0) {
+ // If non-static method, mark "this" as non-null
+ int this_reg = GetFirstInVR();
+ ssa_regs_to_check->ClearBit(this_reg);
+ }
+ } else if (bb->predecessors.size() == 1) {
+ BasicBlock* pred_bb = GetBasicBlock(bb->predecessors[0]);
+ // pred_bb must have already been processed at least once.
+ DCHECK(pred_bb->data_flow_info->ending_check_v != nullptr);
+ ssa_regs_to_check->Copy(pred_bb->data_flow_info->ending_check_v);
+ if (pred_bb->block_type == kDalvikByteCode) {
+ // Check to see if predecessor had an explicit null-check.
+ MIR* last_insn = pred_bb->last_mir_insn;
+ if (last_insn != nullptr) {
+ Instruction::Code last_opcode = last_insn->dalvikInsn.opcode;
+ if (last_opcode == Instruction::IF_EQZ) {
+ if (pred_bb->fall_through == bb->id) {
+ // The fall-through of a block following a IF_EQZ, set the vA of the IF_EQZ to show that
+ // it can't be null.
+ ssa_regs_to_check->ClearBit(last_insn->ssa_rep->uses[0]);
+ }
+ } else if (last_opcode == Instruction::IF_NEZ) {
+ if (pred_bb->taken == bb->id) {
+ // The taken block following a IF_NEZ, set the vA of the IF_NEZ to show that it can't be
+ // null.
+ ssa_regs_to_check->ClearBit(last_insn->ssa_rep->uses[0]);
}
}
}
- } else {
- // Starting state is union of all incoming arcs
- bool copied_first = false;
- for (BasicBlockId pred_id : bb->predecessors) {
- BasicBlock* pred_bb = GetBasicBlock(pred_id);
- DCHECK(pred_bb != nullptr);
- DCHECK(pred_bb->data_flow_info != nullptr);
- if (pred_bb->data_flow_info->ending_check_v == nullptr) {
- continue;
- }
- if (!copied_first) {
- copied_first = true;
- ssa_regs_to_check->Copy(pred_bb->data_flow_info->ending_check_v);
- } else {
- ssa_regs_to_check->Union(pred_bb->data_flow_info->ending_check_v);
- }
- }
- DCHECK(copied_first); // At least one predecessor must have been processed before this bb.
}
- // At this point, ssa_regs_to_check shows which sregs have an object definition with
- // no intervening uses.
+ } else {
+ // Starting state is union of all incoming arcs
+ bool copied_first = false;
+ for (BasicBlockId pred_id : bb->predecessors) {
+ BasicBlock* pred_bb = GetBasicBlock(pred_id);
+ DCHECK(pred_bb != nullptr);
+ DCHECK(pred_bb->data_flow_info != nullptr);
+ if (pred_bb->data_flow_info->ending_check_v == nullptr) {
+ continue;
+ }
+ if (!copied_first) {
+ copied_first = true;
+ ssa_regs_to_check->Copy(pred_bb->data_flow_info->ending_check_v);
+ } else {
+ ssa_regs_to_check->Union(pred_bb->data_flow_info->ending_check_v);
+ }
+ }
+ DCHECK(copied_first); // At least one predecessor must have been processed before this bb.
}
+ // At this point, ssa_regs_to_check shows which sregs have an object definition with
+ // no intervening uses.
// Walk through the instruction in the block, updating as necessary
for (MIR* mir = bb->first_mir_insn; mir != NULL; mir = mir->next) {
@@ -916,12 +915,6 @@
continue;
}
- // Propagate type info.
- infer_changed = InferTypeAndSize(bb, mir, infer_changed);
- if (!do_nce) {
- continue;
- }
-
uint64_t df_attributes = GetDataFlowAttributes(mir);
// Might need a null check?
@@ -1022,35 +1015,50 @@
// Did anything change?
bool nce_changed = false;
- if (do_nce) {
- if (bb->data_flow_info->ending_check_v == nullptr) {
- DCHECK(temp_scoped_alloc_.get() != nullptr);
- bb->data_flow_info->ending_check_v = new (temp_scoped_alloc_.get()) ArenaBitVector(
- temp_scoped_alloc_.get(), temp_bit_vector_size_, false, kBitMapNullCheck);
- nce_changed = ssa_regs_to_check->GetHighestBitSet() != -1;
- bb->data_flow_info->ending_check_v->Copy(ssa_regs_to_check);
- } else if (!ssa_regs_to_check->SameBitsSet(bb->data_flow_info->ending_check_v)) {
- nce_changed = true;
- bb->data_flow_info->ending_check_v->Copy(ssa_regs_to_check);
- }
+ if (bb->data_flow_info->ending_check_v == nullptr) {
+ DCHECK(temp_scoped_alloc_.get() != nullptr);
+ bb->data_flow_info->ending_check_v = new (temp_scoped_alloc_.get()) ArenaBitVector(
+ temp_scoped_alloc_.get(), temp_bit_vector_size_, false, kBitMapNullCheck);
+ nce_changed = ssa_regs_to_check->GetHighestBitSet() != -1;
+ bb->data_flow_info->ending_check_v->Copy(ssa_regs_to_check);
+ } else if (!ssa_regs_to_check->SameBitsSet(bb->data_flow_info->ending_check_v)) {
+ nce_changed = true;
+ bb->data_flow_info->ending_check_v->Copy(ssa_regs_to_check);
}
- return infer_changed | nce_changed;
+ return nce_changed;
}
-void MIRGraph::EliminateNullChecksAndInferTypesEnd() {
- if ((cu_->disable_opt & (1 << kNullCheckElimination)) == 0) {
- // Clean up temporaries.
- temp_bit_vector_size_ = 0u;
- temp_bit_vector_ = nullptr;
- AllNodesIterator iter(this);
- for (BasicBlock* bb = iter.Next(); bb != nullptr; bb = iter.Next()) {
- if (bb->data_flow_info != nullptr) {
- bb->data_flow_info->ending_check_v = nullptr;
- }
+void MIRGraph::EliminateNullChecksEnd() {
+ // Clean up temporaries.
+ temp_bit_vector_size_ = 0u;
+ temp_bit_vector_ = nullptr;
+ AllNodesIterator iter(this);
+ for (BasicBlock* bb = iter.Next(); bb != nullptr; bb = iter.Next()) {
+ if (bb->data_flow_info != nullptr) {
+ bb->data_flow_info->ending_check_v = nullptr;
}
- DCHECK(temp_scoped_alloc_.get() != nullptr);
- temp_scoped_alloc_.reset();
}
+ DCHECK(temp_scoped_alloc_.get() != nullptr);
+ temp_scoped_alloc_.reset();
+}
+
+/*
+ * Perform type and size inference for a basic block.
+ */
+bool MIRGraph::InferTypes(BasicBlock* bb) {
+ if (bb->data_flow_info == nullptr) return false;
+
+ bool infer_changed = false;
+ for (MIR* mir = bb->first_mir_insn; mir != NULL; mir = mir->next) {
+ if (mir->ssa_rep == NULL) {
+ continue;
+ }
+
+ // Propagate type info.
+ infer_changed = InferTypeAndSize(bb, mir, infer_changed);
+ }
+
+ return infer_changed;
}
bool MIRGraph::EliminateClassInitChecksGate() {
diff --git a/compiler/dex/pass_driver_me_opts.cc b/compiler/dex/pass_driver_me_opts.cc
index 6281062..cd3ffd4 100644
--- a/compiler/dex/pass_driver_me_opts.cc
+++ b/compiler/dex/pass_driver_me_opts.cc
@@ -37,7 +37,8 @@
GetPassInstance<CacheMethodLoweringInfo>(),
GetPassInstance<SpecialMethodInliner>(),
GetPassInstance<CodeLayout>(),
- GetPassInstance<NullCheckEliminationAndTypeInference>(),
+ GetPassInstance<NullCheckElimination>(),
+ GetPassInstance<TypeInference>(),
GetPassInstance<ClassInitCheckElimination>(),
GetPassInstance<GlobalValueNumberingPass>(),
GetPassInstance<BBCombine>(),
