Re-landing of "replace TrySync with Metadata".

runtime/vm/flow_graph_compiler.cc

Index: runtime/vm/flow_graph_compiler.cc
diff --git a/runtime/vm/flow_graph_compiler.cc b/runtime/vm/flow_graph_compiler.cc
index e1c8a0113e9743421e959d5441295684503e5f4a..665afa336d641d194ad1c16fae6ce58b00088237 100644
--- a/runtime/vm/flow_graph_compiler.cc
+++ b/runtime/vm/flow_graph_compiler.cc
@@ -196,6 +196,7 @@ FlowGraphCompiler::FlowGraphCompiler(
       pc_descriptors_list_(NULL),
       stackmap_table_builder_(NULL),
       code_source_map_builder_(NULL),
+      catch_entry_state_maps_builder_(NULL),
       block_info_(block_order_.length()),
       deopt_infos_(),
       static_calls_target_table_(),
@@ -267,6 +268,7 @@ bool FlowGraphCompiler::IsPotentialUnboxedField(const Field& field) {
 void FlowGraphCompiler::InitCompiler() {
   pc_descriptors_list_ = new (zone()) DescriptorList(64);
   exception_handlers_list_ = new (zone()) ExceptionHandlerList();
+  catch_entry_state_maps_builder_ = new (zone()) CatchEntryStateMapBuilder();
   block_info_.Clear();
   // Conservative detection of leaf routines used to remove the stack check
   // on function entry.
@@ -412,6 +414,91 @@ void FlowGraphCompiler::CompactBlocks() {
 }
 
 
+void FlowGraphCompiler::EmitCatchEntryState(Environment* env,
+                                            intptr_t try_index) {
+#if defined(DART_PRECOMPILER) || defined(DART_PRECOMPILED_RUNTIME)
+  env = env ? env : pending_deoptimization_env_;
+  try_index = try_index != CatchClauseNode::kInvalidTryIndex
+                  ? try_index
+                  : CurrentTryIndex();
+  if (is_optimizing() && env != NULL &&
+      (try_index != CatchClauseNode::kInvalidTryIndex)) {
+    env = env->Outermost();
+    CatchBlockEntryInstr* catch_block =
+        flow_graph().graph_entry()->GetCatchEntry(try_index);
+    const GrowableArray<Definition*>* idefs =
+        catch_block->initial_definitions();
+    catch_entry_state_maps_builder_->NewMapping(assembler()->CodeSize());
+    // Parameters first.
+    intptr_t i = 0;
+    const intptr_t num_non_copied_params = flow_graph().num_non_copied_params();
+    for (; i < num_non_copied_params; ++i) {
+      // Don't sync captured parameters. They are not in the environment.
+      if (flow_graph().captured_parameters()->Contains(i)) continue;
+      if ((*idefs)[i]->IsConstant()) continue;  // Common constants.
+      Location src = env->LocationAt(i);
+      intptr_t dest_index = i - num_non_copied_params;
+      if (!src.IsStackSlot()) {
+        ASSERT(src.IsConstant());
+        // Skip dead locations.
+        if (src.constant().raw() == Symbols::OptimizedOut().raw()) {
+          continue;
+        }
+        intptr_t id =
+            assembler()->object_pool_wrapper().FindObject(src.constant());
+        catch_entry_state_maps_builder_->AppendConstant(id, dest_index);
+        continue;
+      }
+      if (src.stack_index() != dest_index) {
+        catch_entry_state_maps_builder_->AppendMove(src.stack_index(),
+                                                    dest_index);
+      }
+    }
+
+    // Process locals. Skip exception_var and stacktrace_var.
+    intptr_t local_base = kFirstLocalSlotFromFp + num_non_copied_params;
+    intptr_t ex_idx = local_base - catch_block->exception_var().index();
+    intptr_t st_idx = local_base - catch_block->stacktrace_var().index();
+    for (; i < flow_graph().variable_count(); ++i) {
+      // Don't sync captured parameters. They are not in the environment.
+      if (flow_graph().captured_parameters()->Contains(i)) continue;
+      if (i == ex_idx || i == st_idx) continue;
+      if ((*idefs)[i]->IsConstant()) continue;  // Common constants.
+      Location src = env->LocationAt(i);
+      if (src.IsInvalid()) continue;
+      intptr_t dest_index = i - num_non_copied_params;
+      if (!src.IsStackSlot()) {
+        ASSERT(src.IsConstant());
+        // Skip dead locations.
+        if (src.constant().raw() == Symbols::OptimizedOut().raw()) {
+          continue;
+        }
+        intptr_t id =
+            assembler()->object_pool_wrapper().FindObject(src.constant());
+        catch_entry_state_maps_builder_->AppendConstant(id, dest_index);
+        continue;
+      }
+      if (src.stack_index() != dest_index) {
+        catch_entry_state_maps_builder_->AppendMove(src.stack_index(),
+                                                    dest_index);
+      }
+    }
+    catch_entry_state_maps_builder_->EndMapping();
+  }
+#endif  // defined(DART_PRECOMPILER) || defined(DART_PRECOMPILED_RUNTIME)
+}
+
+
+void FlowGraphCompiler::EmitCallsiteMetaData(TokenPosition token_pos,
+                                             intptr_t deopt_id,
+                                             RawPcDescriptors::Kind kind,
+                                             LocationSummary* locs) {
+  AddCurrentDescriptor(kind, deopt_id, token_pos);
+  RecordSafepoint(locs);
+  EmitCatchEntryState();
+}
+
+
 void FlowGraphCompiler::EmitInstructionPrologue(Instruction* instr) {
   if (!is_optimizing()) {
     if (instr->CanBecomeDeoptimizationTarget() && !instr->IsGoto()) {
@@ -422,10 +509,6 @@ void FlowGraphCompiler::EmitInstructionPrologue(Instruction* instr) {
                            instr->token_pos());
     }
     AllocateRegistersLocally(instr);
-  } else if (instr->MayThrow() &&
-             (CurrentTryIndex() != CatchClauseNode::kInvalidTryIndex)) {
-    // Optimized try-block: Sync locals to fixed stack locations.
-    EmitTrySync(instr, CurrentTryIndex());
   }
 }
 
@@ -544,69 +627,6 @@ void FlowGraphCompiler::Bailout(const char* reason) {
 }
 
 
-void FlowGraphCompiler::EmitTrySync(Instruction* instr, intptr_t try_index) {
-  ASSERT(is_optimizing());
-  Environment* env = instr->env()->Outermost();
-  CatchBlockEntryInstr* catch_block =
-      flow_graph().graph_entry()->GetCatchEntry(try_index);
-  const GrowableArray<Definition*>* idefs = catch_block->initial_definitions();
-
-  // Construct a ParallelMove instruction for parameters and locals. Skip the
-  // special locals exception_var and stacktrace_var since they will be filled
-  // when an exception is thrown. Constant locations are known to be the same
-  // at all instructions that may throw, and do not need to be materialized.
-
-  // Parameters first.
-  intptr_t i = 0;
-  const intptr_t num_non_copied_params = flow_graph().num_non_copied_params();
-  ParallelMoveInstr* move_instr = new (zone()) ParallelMoveInstr();
-  for (; i < num_non_copied_params; ++i) {
-    // Don't sync captured parameters. They are not in the environment.
-    if (flow_graph().captured_parameters()->Contains(i)) continue;
-    if ((*idefs)[i]->IsConstant()) continue;  // Common constants
-    Location src = env->LocationAt(i);
-#if defined(TARGET_ARCH_DBC)
-    intptr_t dest_index = kNumberOfCpuRegisters - 1 - i;
-    Location dest = Location::RegisterLocation(dest_index);
-    // Update safepoint bitmap to indicate that the target location
-    // now contains a pointer. With DBC parameters are copied into
-    // the locals area.
-    instr->locs()->SetStackBit(dest_index);
-#else
-    intptr_t dest_index = i - num_non_copied_params;
-    Location dest = Location::StackSlot(dest_index);
-#endif
-    move_instr->AddMove(dest, src);
-  }
-
-  // Process locals. Skip exception_var and stacktrace_var.
-  intptr_t local_base = kFirstLocalSlotFromFp + num_non_copied_params;
-  intptr_t ex_idx = local_base - catch_block->exception_var().index();
-  intptr_t st_idx = local_base - catch_block->stacktrace_var().index();
-  for (; i < flow_graph().variable_count(); ++i) {
-    // Don't sync captured parameters. They are not in the environment.
-    if (flow_graph().captured_parameters()->Contains(i)) continue;
-    if (i == ex_idx || i == st_idx) continue;
-    if ((*idefs)[i]->IsConstant()) continue;
-    Location src = env->LocationAt(i);
-    ASSERT(!src.IsFpuRegister());
-    ASSERT(!src.IsDoubleStackSlot());
-#if defined(TARGET_ARCH_DBC)
-    intptr_t dest_index = kNumberOfCpuRegisters - 1 - i;
-    Location dest = Location::RegisterLocation(dest_index);
-#else
-    intptr_t dest_index = i - num_non_copied_params;
-    Location dest = Location::StackSlot(dest_index);
-#endif
-    move_instr->AddMove(dest, src);
-    // Update safepoint bitmap to indicate that the target location
-    // now contains a pointer.
-    instr->locs()->SetStackBit(dest_index);
-  }
-  parallel_move_resolver()->EmitNativeCode(move_instr);
-}
-
-
 intptr_t FlowGraphCompiler::StackSize() const {
   if (is_optimizing_) {
     return flow_graph_.graph_entry()->spill_slot_count();
@@ -1015,6 +1035,15 @@ void FlowGraphCompiler::FinalizeVarDescriptors(const Code& code) {
   code.set_var_descriptors(var_descs);
 }
 
+void FlowGraphCompiler::FinalizeCatchEntryStateMap(const Code& code) {
+#if defined(DART_PRECOMPILED_RUNTIME) || defined(DART_PRECOMPILER)
+  TypedData& maps = TypedData::Handle(
+      catch_entry_state_maps_builder_->FinalizeCatchEntryStateMap());
+  code.set_catch_entry_state_maps(maps);
+#else
+  code.set_variables(Smi::Handle(Smi::New(flow_graph().variable_count())));
+#endif
+}
 
 void FlowGraphCompiler::FinalizeStaticCallTargetsTable(const Code& code) {
   ASSERT(code.static_calls_target_table() == Array::null());
@@ -1123,6 +1152,23 @@ bool FlowGraphCompiler::TryIntrinsify() {
 // DBC is very different from other architectures in how it performs instance
 // and static calls because it does not use stubs.
 #if !defined(TARGET_ARCH_DBC)
+void FlowGraphCompiler::GenerateCallWithDeopt(TokenPosition token_pos,
+                                              intptr_t deopt_id,
+                                              const StubEntry& stub_entry,
+                                              RawPcDescriptors::Kind kind,
+                                              LocationSummary* locs) {
+  GenerateCall(token_pos, stub_entry, kind, locs);
+  const intptr_t deopt_id_after = Thread::ToDeoptAfter(deopt_id);
+  if (is_optimizing()) {
+    AddDeoptIndexAtCall(deopt_id_after);
+  } else {
+    // Add deoptimization continuation point after the call and before the
+    // arguments are removed.
+    AddCurrentDescriptor(RawPcDescriptors::kDeopt, deopt_id_after, token_pos);
+  }
+}
+
+
 void FlowGraphCompiler::GenerateInstanceCall(intptr_t deopt_id,
                                              TokenPosition token_pos,
                                              intptr_t argument_count,