Inline instanceOf and 'as' operations; fix a bug in code emission

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 2db078f4b423afbaee61bad65e8a6e18f191df67..91e6a58dbb6370afc112530f318645444b1c48cc 100644
--- a/runtime/vm/flow_graph_optimizer.cc
+++ b/runtime/vm/flow_graph_optimizer.cc
@@ -4088,7 +4088,8 @@ void FlowGraphOptimizer::ReplaceWithInstanceOf(InstanceCallInstr* call) {
     // reported, so do not replace the instance call.
     return;
   }
-  if (unary_checks.NumberOfChecks() <= FLAG_max_polymorphic_checks) {
+  if ((unary_checks.NumberOfChecks() > 0) &&
+      (unary_checks.NumberOfChecks() <= FLAG_max_polymorphic_checks)) {
     ZoneGrowableArray<intptr_t>* results =
         new(Z) ZoneGrowableArray<intptr_t>(unary_checks.NumberOfChecks() * 2);
     Bool& as_bool =
@@ -4179,7 +4180,8 @@ void FlowGraphOptimizer::ReplaceWithTypeCast(InstanceCallInstr* call) {
     // reported, so do not replace the instance call.
     return;
   }
-  if (unary_checks.NumberOfChecks() <= FLAG_max_polymorphic_checks) {
+  if ((unary_checks.NumberOfChecks() > 0) &&
+      (unary_checks.NumberOfChecks() <= FLAG_max_polymorphic_checks)) {
     ZoneGrowableArray<intptr_t>* results =
         new(Z) ZoneGrowableArray<intptr_t>(unary_checks.NumberOfChecks() * 2);
     const Bool& as_bool = Bool::ZoneHandle(Z,
@@ -4213,22 +4215,41 @@ void FlowGraphOptimizer::ReplaceWithTypeCast(InstanceCallInstr* call) {
 }
 
 
+// Special optimizations when running in --noopt mode.
+void FlowGraphOptimizer::InstanceCallNoopt(InstanceCallInstr* instr) {
+  // TODO(srdjan): Investigate other attempts, as they are not allowed to
+  // deoptimize.
+  const Token::Kind op_kind = instr->token_kind();
+  if (instr->HasICData() && (instr->ic_data()->NumberOfUsedChecks() > 0)) {
+    if ((op_kind == Token::kGET) && TryInlineInstanceGetter(instr, false)) {
+      return;
+    }
+  }
+
+  // Type test is special as it always gets converted into inlined code.
+  if (Token::IsTypeTestOperator(op_kind)) {
+    ReplaceWithInstanceOf(instr);
+    return;
+  }
+  if (Token::IsTypeCastOperator(op_kind)) {
+    ReplaceWithTypeCast(instr);
+    return;
+  }
+}
+
+
 // Tries to optimize instance call by replacing it with a faster instruction
 // (e.g, binary op, field load, ..).
 void FlowGraphOptimizer::VisitInstanceCall(InstanceCallInstr* instr) {
-  if (!instr->HasICData() || (instr->ic_data()->NumberOfUsedChecks() == 0)) {
+  if (Compiler::always_optimize()) {
+    InstanceCallNoopt(instr);
     return;
   }
 
-  const Token::Kind op_kind = instr->token_kind();
-  if (Compiler::always_optimize()) {
-    // TODO(srdjan): Investigate other attempts, as they are not allowed to
-    // deoptimize.
-    if ((op_kind == Token::kGET) && TryInlineInstanceGetter(instr, false)) {
-      return;
-    }
+  if (!instr->HasICData() || (instr->ic_data()->NumberOfUsedChecks() == 0)) {
     return;
   }
+  const Token::Kind op_kind = instr->token_kind();
 
   // Type test is special as it always gets converted into inlined code.
   if (Token::IsTypeTestOperator(op_kind)) {