More general CHA-based inlining and devirtualization for precompiled code.

runtime/vm/flow_graph_compiler.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/globals.h"  // Needed here to get TARGET_ARCH_XXX.
 
 #include "vm/flow_graph_compiler.h"
 
 #include "vm/bit_vector.h"
 #include "vm/cha.h"
@@ skipping 234 matching lines @@
       for (ForwardInstructionIterator it(entry); !it.Done(); it.Advance()) {
         Instruction* current = it.Current();
         if (current->IsBranch()) {
           current = current->AsBranch()->comparison();
         }
         // In optimized code, ICData is always set in the instructions.
         const ICData* ic_data = NULL;
         if (current->IsInstanceCall()) {
           ic_data = current->AsInstanceCall()->ic_data();
         }
-        if ((ic_data != NULL) && (ic_data->NumberOfUsedChecks() == 0)) {
+        if ((ic_data == NULL) ||
+            ((ic_data != NULL) && (ic_data->NumberOfUsedChecks() == 0))) {

[srdjan, 2015/10/21 17:37:46]

When do you see ic_data NULL, except for precompilation and there we do not want
to set may_reoptimize to true.

[Florian Schneider, 2015/10/22 13:59:25]

Same here. Defensive left over check.

           may_reoptimize_ = true;

[rmacnak, 2015/10/21 18:00:30]

Can we rename this to has_ic_calls_ or, probably better, not flip it when
allow_recompilation_ == false?

[Florian Schneider, 2015/10/22 13:59:25]

may_reoptimize_ has no effect with precompilation even now because the
FLAG_optimization_counter_threshold is set to -1.

         }
         if (is_leaf &&
             !current->IsCheckStackOverflow() &&
             !current->IsParallelMove()) {
           // Note that we do not care if the code contains instructions that
           // can deoptimize.
           LocationSummary* locs = current->locs();
           if ((locs != NULL) && locs->can_call()) {
             is_leaf = false;
           }
@@ skipping 823 matching lines @@
     const ICData& ic_data) {
   if (FLAG_always_megamorphic_calls) {
     EmitMegamorphicInstanceCall(ic_data, argument_count,
                                 deopt_id, token_pos, locs);
     return;
   }
   ASSERT(!ic_data.IsNull());
   if (is_optimizing() && (ic_data.NumberOfUsedChecks() == 0)) {
     // Emit IC call that will count and thus may need reoptimization at
     // function entry.
-    ASSERT(!is_optimizing()
-           || may_reoptimize()
-           || flow_graph().IsCompiledForOsr());
+    ASSERT(may_reoptimize() || flow_graph().IsCompiledForOsr());
     switch (ic_data.NumArgsTested()) {
       case 1:
         EmitOptimizedInstanceCall(
             *StubCode::OneArgOptimizedCheckInlineCache_entry(), ic_data,
             argument_count, deopt_id, token_pos, locs);
         return;
       case 2:
         EmitOptimizedInstanceCall(
             *StubCode::TwoArgsOptimizedCheckInlineCache_entry(), ic_data,
             argument_count, deopt_id, token_pos, locs);
@@ skipping 703 matching lines @@
 
 
 void FlowGraphCompiler::FrameStateClear() {
   ASSERT(!is_optimizing());
   frame_state_.TruncateTo(0);
 }
 #endif
 
 
 }  // namespace dart