Polymorphic calls in precompilation invoke megamorphic calls when tests fail (instead of deoptimizi…

runtime/vm/flow_graph_compiler_arm64.cc

 // Copyright (c) 2014, 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_ARM64.
 #if defined(TARGET_ARCH_ARM64)
 
 #include "vm/flow_graph_compiler.h"
 
 #include "vm/ast_printer.h"
@@ skipping 10 matching lines @@
 #include "vm/stub_code.h"
 #include "vm/symbols.h"
 
 namespace dart {
 
 DEFINE_FLAG(bool, trap_on_deoptimization, false, "Trap on deoptimization.");
 DECLARE_FLAG(bool, enable_simd_inline);
 DECLARE_FLAG(bool, use_megamorphic_stub);
 
 
+void MegamorphicSlowPath::EmitNativeCode(FlowGraphCompiler* compiler) {
+  Assembler* assembler = compiler->assembler();
+#define __ assembler->
+  __ Bind(entry_label());
+  __ Comment("MegamorphicSlowPath");
+  compiler->EmitMegamorphicInstanceCall(ic_data_, argument_count_, deopt_id_,
+                                        token_pos_, locs_, try_index_);
+  __ b(exit_label());
+#undef __
+}
+
+
 FlowGraphCompiler::~FlowGraphCompiler() {
   // BlockInfos are zone-allocated, so their destructors are not called.
   // Verify the labels explicitly here.
   for (int i = 0; i < block_info_.length(); ++i) {
     ASSERT(!block_info_[i]->jump_label()->IsLinked());
   }
 }
 
 
 bool FlowGraphCompiler::SupportsUnboxedDoubles() {
@@ skipping 124 matching lines @@
   }
 
   return builder->CreateDeoptInfo(deopt_table);
 }
 
 
 void CompilerDeoptInfoWithStub::GenerateCode(FlowGraphCompiler* compiler,
                                              intptr_t stub_ix) {
   // Calls do not need stubs, they share a deoptimization trampoline.
   ASSERT(reason() != ICData::kDeoptAtCall);
-  Assembler* assem = compiler->assembler();
-#define __ assem->
+  Assembler* assembler = compiler->assembler();
+#define __ assembler->
   __ Comment("%s", Name());
   __ Bind(entry_label());
   if (FLAG_trap_on_deoptimization) {
     __ brk(0);
   }
 
   ASSERT(deopt_env() != NULL);
   __ Push(CODE_REG);
   __ BranchLink(*StubCode::Deoptimize_entry());
-  set_pc_offset(assem->CodeSize());
+  set_pc_offset(assembler->CodeSize());
 #undef __
 }
 
 
 #define __ assembler()->
 
 
 // Fall through if bool_register contains null.
 void FlowGraphCompiler::GenerateBoolToJump(Register bool_register,
                                            Label* is_true,
@@ skipping 1044 matching lines @@
                    locs);
   __ Drop(argument_count);
 }
 
 
 void FlowGraphCompiler::EmitMegamorphicInstanceCall(
     const ICData& ic_data,
     intptr_t argument_count,
     intptr_t deopt_id,
     intptr_t token_pos,
-    LocationSummary* locs) {
+    LocationSummary* locs,
+    intptr_t try_index) {
   const String& name = String::Handle(zone(), ic_data.target_name());
   const Array& arguments_descriptor =
       Array::ZoneHandle(zone(), ic_data.arguments_descriptor());
   ASSERT(!arguments_descriptor.IsNull() && (arguments_descriptor.Length() > 0));
   const MegamorphicCache& cache = MegamorphicCache::ZoneHandle(zone(),
       MegamorphicCacheTable::Lookup(isolate(), name, arguments_descriptor));
 
   __ Comment("MegamorphicCall");
   __ LoadFromOffset(R0, SP, (argument_count - 1) * kWordSize);
   __ LoadObject(R5, cache);
   if (FLAG_use_megamorphic_stub) {
     __ BranchLink(*StubCode::MegamorphicLookup_entry());
   } else  {
     StubCode::EmitMegamorphicLookup(assembler());
   }
   __ blr(R1);
 
-  AddCurrentDescriptor(RawPcDescriptors::kOther,
-      Thread::kNoDeoptId, token_pos);
   RecordSafepoint(locs);
   const intptr_t deopt_id_after = Thread::ToDeoptAfter(deopt_id);
-  if (is_optimizing()) {
+  if (Compiler::always_optimize()) {
+    // Megamorphic calls may occur in slow path stubs.
+    // If valid use try_index argument.
+    if (try_index == CatchClauseNode::kInvalidTryIndex) {
+      try_index = CurrentTryIndex();
+    }
+    pc_descriptors_list()->AddDescriptor(RawPcDescriptors::kOther,
+                                         assembler()->CodeSize(),
+                                         Thread::kNoDeoptId,
+                                         token_pos,
+                                         try_index);
+  } else if (is_optimizing()) {
+    AddCurrentDescriptor(RawPcDescriptors::kOther,
+        Thread::kNoDeoptId, token_pos);
     AddDeoptIndexAtCall(deopt_id_after, token_pos);
   } else {
+    AddCurrentDescriptor(RawPcDescriptors::kOther,
+        Thread::kNoDeoptId, token_pos);
     // Add deoptimization continuation point after the call and before the
     // arguments are removed.
     AddCurrentDescriptor(RawPcDescriptors::kDeopt, deopt_id_after, token_pos);
   }
   __ Drop(argument_count);
 }
 
 
 void FlowGraphCompiler::EmitSwitchableInstanceCall(
     const ICData& ic_data,
@@ skipping 571 matching lines @@
 void ParallelMoveResolver::RestoreFpuScratch(FpuRegister reg) {
   __ PopDouble(reg);
 }
 
 
 #undef __
 
 }  // namespace dart
 
 #endif  // defined TARGET_ARCH_ARM64