Specialize instance calls when the call receiver is the method receiver and the method class has a …

runtime/vm/flow_graph_inliner.cc

 // Copyright (c) 2013, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 #include "vm/flow_graph_inliner.h"
 
 #include "vm/aot_optimizer.h"
 #include "vm/block_scheduler.h"
 #include "vm/branch_optimizer.h"
 #include "vm/compiler.h"
@@ skipping 1196 matching lines @@
 
   void InlineInstanceCalls() {
     const GrowableArray<CallSites::InstanceCallInfo>& call_info =
         inlining_call_sites_->instance_calls();
     TRACE_INLINING(THR_Print("  Polymorphic Instance Calls (%" Pd ")\n",
                              call_info.length()));
     for (intptr_t call_idx = 0; call_idx < call_info.length(); ++call_idx) {
       PolymorphicInstanceCallInstr* call = call_info[call_idx].call;
       if (call->with_checks()) {
         // PolymorphicInliner introduces deoptimization paths.
-        if (!FLAG_polymorphic_with_deopt) {
+        if (!call->complete() && !FLAG_polymorphic_with_deopt) {
           TRACE_INLINING(THR_Print(
               "  => %s\n     Bailout: call with checks\n",
               call->instance_call()->function_name().ToCString()));
           continue;
         }
         const Function& cl = call_info[call_idx].caller();
         intptr_t caller_inlining_id =
             call_info[call_idx].caller_graph->inlining_id();
         PolymorphicInliner inliner(this, call, cl, caller_inlining_id);
         inliner.Inline();
@@ skipping 396 matching lines @@
   // at least one branch on the class id.
   LoadClassIdInstr* load_cid =
       new(Z) LoadClassIdInstr(new(Z) Value(receiver));
   load_cid->set_ssa_temp_index(owner_->caller_graph()->alloc_ssa_temp_index());
   cursor = AppendInstruction(cursor, load_cid);
   for (intptr_t i = 0; i < inlined_variants_.length(); ++i) {
     // 1. Guard the body with a class id check.
     if ((i == (inlined_variants_.length() - 1)) &&
         non_inlined_variants_.is_empty()) {
       // If it is the last variant use a check class id instruction which can
-      // deoptimize, followed unconditionally by the body.
-      RedefinitionInstr* cid_redefinition =
-          new RedefinitionInstr(new(Z) Value(load_cid));
-      cid_redefinition->set_ssa_temp_index(
-          owner_->caller_graph()->alloc_ssa_temp_index());
-      cursor = AppendInstruction(cursor, cid_redefinition);
-      CheckClassIdInstr* check_class_id = new(Z) CheckClassIdInstr(
-          new(Z) Value(cid_redefinition),
-          inlined_variants_[i].cid,
-          call_->deopt_id());
-      check_class_id->InheritDeoptTarget(zone(), call_);
-      cursor = AppendInstruction(cursor, check_class_id);
+      // deoptimize, followed unconditionally by the body. Omit the check if
+      // we know that we have covered all possible classes.
+      if (!call_->complete()) {
+        RedefinitionInstr* cid_redefinition =
+            new RedefinitionInstr(new(Z) Value(load_cid));
+        cid_redefinition->set_ssa_temp_index(
+            owner_->caller_graph()->alloc_ssa_temp_index());
+        cursor = AppendInstruction(cursor, cid_redefinition);
+        CheckClassIdInstr* check_class_id = new(Z) CheckClassIdInstr(
+            new(Z) Value(cid_redefinition),
+            inlined_variants_[i].cid,
+            call_->deopt_id());
+        check_class_id->InheritDeoptTarget(zone(), call_);
+        cursor = AppendInstruction(cursor, check_class_id);
+      }
 
       // The next instruction is the first instruction of the inlined body.
       // Handle the two possible cases (unshared and shared subsequent
       // predecessors) separately.
       BlockEntryInstr* callee_entry = inlined_entries_[i];
       if (callee_entry->IsGraphEntry()) {
         // Unshared.  Graft the normal entry on after the check class
         // instruction.
         TargetEntryInstr* target =
             callee_entry->AsGraphEntry()->normal_entry();
@@ skipping 112 matching lines @@
                     old_checks.deopt_id(),
                     1));  // Number of args tested.
     for (intptr_t i = 0; i < non_inlined_variants_.length(); ++i) {
       new_checks.AddReceiverCheck(non_inlined_variants_[i].cid,
                                   *non_inlined_variants_[i].target,
                                   non_inlined_variants_[i].count);
     }
     PolymorphicInstanceCallInstr* fallback_call =
         new PolymorphicInstanceCallInstr(call_->instance_call(),
                                          new_checks,
-                                         true);  // With checks.
+                                         true,  // With checks.
+                                         call_->complete());  // Complete.

[Florian Schneider, 2016/04/08 22:39:38]

This call could avoid the slow path code if you change
FlowGraphCompiler::EmitPolymorphicInstanceCall and EmitTestAndCall to check if
'complete' is true.

     fallback_call->set_ssa_temp_index(
         owner_->caller_graph()->alloc_ssa_temp_index());
     fallback_call->InheritDeoptTarget(zone(), call_);
     ReturnInstr* fallback_return =
         new ReturnInstr(call_->instance_call()->token_pos(),
                         new Value(fallback_call));
     fallback_return->InheritDeoptTargetAfter(
         owner_->caller_graph(),
         call_,
         fallback_call);
@@ skipping 1074 matching lines @@
 
 bool FlowGraphInliner::TryInlineRecognizedMethod(FlowGraph* flow_graph,
                                                  intptr_t receiver_cid,
                                                  const Function& target,
                                                  Instruction* call,
                                                  Definition* receiver,
                                                  TokenPosition token_pos,
                                                  const ICData& ic_data,
                                                  TargetEntryInstr** entry,
                                                  Definition** last) {
+  if (FLAG_precompiled_mode) {
+    // The graphs generated below include deopts.
+    return false;
+  }
+
   ICData& value_check = ICData::ZoneHandle(Z);
   MethodRecognizer::Kind kind = MethodRecognizer::RecognizeKind(target);
   switch (kind) {
     // Recognized [] operators.
     case MethodRecognizer::kImmutableArrayGetIndexed:
     case MethodRecognizer::kObjectArrayGetIndexed:
     case MethodRecognizer::kGrowableArrayGetIndexed:
     case MethodRecognizer::kInt8ArrayGetIndexed:
     case MethodRecognizer::kUint8ArrayGetIndexed:
     case MethodRecognizer::kUint8ClampedArrayGetIndexed:
@@ skipping 214 matching lines @@
       return InlineDoubleOp(flow_graph, Token::kMUL, call, entry, last);
     case MethodRecognizer::kDoubleDiv:
       return InlineDoubleOp(flow_graph, Token::kDIV, call, entry, last);
     default:
       return false;
   }
 }
 
 
 }  // namespace dart