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

runtime/vm/flow_graph_optimizer.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/flow_graph_optimizer.h"
 
 #include "vm/bit_vector.h"
 #include "vm/cha.h"
 #include "vm/compiler.h"
 #include "vm/cpu.h"
@@ skipping 4070 matching lines @@
       ICData::ZoneHandle(Z, call->ic_data()->AsUnaryClassChecks());
   if (FLAG_warn_on_javascript_compatibility &&
       !unary_checks.IssuedJSWarning() &&
       (type.IsIntType() || type.IsDoubleType() || !type.IsInstantiated())) {
     // No warning was reported yet for this type check, either because it has
     // not been executed yet, or because no problematic combinations of instance
     // type and test type have been encountered so far. A warning may still be
     // 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 =
         Bool::ZoneHandle(Z, InstanceOfAsBool(unary_checks, type, results));
     if (as_bool.IsNull()) {
       if (results->length() == unary_checks.NumberOfChecks() * 2) {
         const bool can_deopt = TryExpandTestCidsResult(results, type);
         TestCidsInstr* test_cids = new(Z) TestCidsInstr(
             call->token_pos(),
             negate ? Token::kISNOT : Token::kIS,
@@ skipping 70 matching lines @@
       ICData::ZoneHandle(Z, call->ic_data()->AsUnaryClassChecks());
   if (FLAG_warn_on_javascript_compatibility &&
       !unary_checks.IssuedJSWarning() &&
       (type.IsIntType() || type.IsDoubleType() || !type.IsInstantiated())) {
     // No warning was reported yet for this type check, either because it has
     // not been executed yet, or because no problematic combinations of instance
     // type and test type have been encountered so far. A warning may still be
     // 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,
         InstanceOfAsBool(unary_checks, type, results));
     if (as_bool.raw() == Bool::True().raw()) {
       AddReceiverCheck(call);
       // Remove the original push arguments.
       for (intptr_t i = 0; i < call->ArgumentCount(); ++i) {
         PushArgumentInstr* push = call->PushArgumentAt(i);
         push->ReplaceUsesWith(push->value()->definition());
@@ skipping 13 matching lines @@
                                    new(Z) Value(left),
                                    new(Z) Value(instantiator),
                                    new(Z) Value(type_args),
                                    type,
                                    dst_name,
                                    call->deopt_id());
   ReplaceCall(call, assert_as);
 }
 
 
+// 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 (Compiler::always_optimize()) {
+    InstanceCallNoopt(instr);
+    return;
+  }
+
   if (!instr->HasICData() || (instr->ic_data()->NumberOfUsedChecks() == 0)) {
     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;
-    }
-    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;
@@ skipping 4425 matching lines @@
 
   // Insert materializations at environment uses.
   for (intptr_t i = 0; i < exits_collector_.exits().length(); i++) {
     CreateMaterializationAt(
         exits_collector_.exits()[i], alloc, *slots);
   }
 }
 
 
 }  // namespace dart