DBC: Eager deoptimization and CheckSmi instruction.

runtime/vm/flow_graph_compiler_dbc.cc

 // Copyright (c) 2016, 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_DBC.
 #if defined(TARGET_ARCH_DBC)
 
 #include "vm/flow_graph_compiler.h"
 
 #include "vm/ast_printer.h"
@@ skipping 191 matching lines @@
     // In optimized code this descriptor is needed for exception handling.
     AddCurrentDescriptor(RawPcDescriptors::kDeopt,
                          deopt_id_after,
                          instr->token_pos());
   }
 }
 
 
 void CompilerDeoptInfoWithStub::GenerateCode(FlowGraphCompiler* compiler,
                                              intptr_t stub_ix) {
-  UNIMPLEMENTED();
+  // Calls do not need stubs, they share a deoptimization trampoline.

[Vyacheslav Egorov (Google), 2016/06/08 11:58:53]

I don't think we really need DeoptInfoWithStub on DBC. At least not as much as
on other platforms. Instead of doing:

Condition 
Jump stub

We just should do 

Condition 
Deopt ... 

[zra, 2016/06/08 17:46:30]

Done.

+  ASSERT(reason() != ICData::kDeoptAtCall);
+  Assembler* assembler = compiler->assembler();
+#define __ assembler->
+  __ Comment("%s", Name());
+  __ Bind(entry_label());
+  if (FLAG_trap_on_deoptimization) {
+    __ Trap();
+  }
+
+  ASSERT(deopt_env() != NULL);
+  set_pc_offset(assembler->CodeSize());

[zra, 2016/06/07 22:31:28]

On other architectures this comes after the Deopt call. Not sure why I have to
put it in front.

+  __ Deopt(0, deopt_id());
+#undef __
 }
 
 
 #define __ assembler()->
 
 
 void FlowGraphCompiler::GenerateAssertAssignable(TokenPosition token_pos,
                                                  intptr_t deopt_id,
                                                  const AbstractType& dst_type,
                                                  const String& dst_name,
@@ skipping 157 matching lines @@
 void FlowGraphCompiler::CompileGraph() {
   InitCompiler();
 
   if (TryIntrinsify()) {
     // Skip regular code generation.
     return;
   }
 
   EmitFrameEntry();
   VisitBlocks();
+  __ Trap();
+  GenerateDeferredCode();
 }
 
 
 #undef __
 #define __ compiler_->assembler()->
 
 
 void ParallelMoveResolver::EmitMove(int index) {
   MoveOperands* move = moves_[index];
   const Location source = move->src();
@@ skipping 98 matching lines @@
 void ParallelMoveResolver::RestoreFpuScratch(FpuRegister reg) {
   UNIMPLEMENTED();
 }
 
 
 #undef __
 
 }  // namespace dart
 
 #endif  // defined TARGET_ARCH_DBC