Collect type feedback for fields.

runtime/vm/flow_graph_optimizer.cc

Index: runtime/vm/flow_graph_optimizer.cc
diff --git a/runtime/vm/flow_graph_optimizer.cc b/runtime/vm/flow_graph_optimizer.cc
index f89f0d287a5f10291ce2f0e0fb4b0d74ee58ae33..7c9e56aed0e2204341a4bce0bb91e50d8328302b 100644
--- a/runtime/vm/flow_graph_optimizer.cc
+++ b/runtime/vm/flow_graph_optimizer.cc
@@ -1233,6 +1233,12 @@ void FlowGraphOptimizer::InlineImplicitInstanceGetter(InstanceCallInstr* call) {
       field.Offset(),
       AbstractType::ZoneHandle(field.type()),
       field.is_final());
+  if (field.guarded_cid() != kIllegalCid) {
+    load->set_result_cid(field.GuardedCid());
+    load->set_field(&Field::ZoneHandle(field.raw()));
+  }
+  load->set_field_name(String::Handle(field.name()).ToCString());
+
   // Discard the environment from the original instruction because the load
   // can't deoptimize.
   call->RemoveEnvironment();
@@ -1876,6 +1882,25 @@ void FlowGraphOptimizer::ReplaceWithInstanceOf(InstanceCallInstr* call) {
 }
 
 
+void FlowGraphOptimizer::VisitStoreInstanceField(
+    StoreInstanceFieldInstr* instr) {
+  if (!instr->should_emit_field_guard()) return;
+
+  if (instr->field().guarded_cid() != kDynamicCid) {

[Kevin Millikin (Google), 2013/03/12 12:14:56]

I think it's a bit better to always insert the guards in the builder.  Maybe
it's not easy for some reason?

[Vyacheslav Egorov (Google), 2013/03/12 16:54:40]

Done. Though it requires an expression temp to preserve value and leads to a
slightly worse code in the non-optimized case.

+    ASSERT(instr->env() != NULL);
+    // TODO(vegorov) need a deopt id here!
+    InsertBefore(instr,
+                 new GuardFieldInstr(instr->value()->Copy(),
+                                     instr->field(),
+                                     instr->deopt_id()),
+                 instr->env(),
+                 Definition::kEffect);
+  }
+
+  instr->detach_field_guard();
+}
+
+
 // Tries to optimize instance call by replacing it with a faster instruction
 // (e.g, binary op, field load, ..).
 void FlowGraphOptimizer::VisitInstanceCall(InstanceCallInstr* instr) {
@@ -2016,11 +2041,24 @@ bool FlowGraphOptimizer::TryInlineInstanceSetter(InstanceCallInstr* instr,
                  Definition::kEffect);
     needs_store_barrier = kNoStoreBarrier;
   }
+
+  if (field.guarded_cid() != kDynamicCid) {
+    InsertBefore(instr,
+                 new GuardFieldInstr(new Value(instr->ArgumentAt(1)),
+                                     field,
+                                     instr->deopt_id()),
+                 instr->env(),
+                 Definition::kEffect);
+  }
+
+  // Field guard was detached.
+  const bool needs_field_guard = false;
   StoreInstanceFieldInstr* store = new StoreInstanceFieldInstr(
       field,
       new Value(instr->ArgumentAt(0)),
       new Value(instr->ArgumentAt(1)),
-      needs_store_barrier);
+      needs_store_barrier,
+      needs_field_guard);
   // Discard the environment from the original instruction because the store
   // can't deoptimize.
   instr->RemoveEnvironment();
@@ -3777,6 +3815,7 @@ void ConstantPropagator::VisitCheckStackOverflow(
 
 void ConstantPropagator::VisitCheckClass(CheckClassInstr* instr) { }
 
+void ConstantPropagator::VisitGuardField(GuardFieldInstr* instr) { }
 
 void ConstantPropagator::VisitCheckSmi(CheckSmiInstr* instr) { }