For instance call representing numerical comparisons (double and Smi for now) that were never visit…

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/dart_entry.h"
 #include "vm/flow_graph_builder.h"
@@ skipping 44 matching lines @@
   return FLAG_enable_simd_inline;
 }
 
 
 // Optimize instance calls using ICData.
 void FlowGraphOptimizer::ApplyICData() {
   VisitBlocks();
 }
 
 
-// Optimize instance calls using cid.
+// Optimize instance calls using cid. This is called after the optimizer which
+// converts instance calls to instructions has been run. Any remaining
+// instance calls probably do not have IC data.
 // Attempts to convert an instance call (IC call) using propagated class-ids,
 // e.g., receiver class id, guarded-cid.
 void FlowGraphOptimizer::ApplyClassIds() {
   ASSERT(current_iterator_ == NULL);
   for (intptr_t i = 0; i < block_order_.length(); ++i) {
     BlockEntryInstr* entry = block_order_[i];
     ForwardInstructionIterator it(entry);
     current_iterator_ = &it;
     for (; !it.Done(); it.Advance()) {
       Instruction* instr = it.Current();
@@ skipping 13 matching lines @@
         if (compare->IsStrictCompare()) {
           VisitStrictCompare(compare->AsStrictCompare());
         }
       }
     }
     current_iterator_ = NULL;
   }
 }
 
 
+// TODO(srdjan): write tests for others.
+static bool IsNumberCid(intptr_t cid) {
+  return (cid == kSmiCid) || (cid == kDoubleCid);
+}
+
+static bool NoneIsDynamic(const GrowableArray<intptr_t>& cids) {
+  for (intptr_t i = 0; i < cids.length(); i++) {
+    if (cids[i] == kDynamicCid) {
+      return false;
+    }
+  }
+  return true;
+}
+
+
 // Attempt to build ICData for call using propagated class-ids.
 bool FlowGraphOptimizer::TryCreateICData(InstanceCallInstr* call) {
   ASSERT(call->HasICData());
   if (call->ic_data()->NumberOfChecks() > 0) {
-    // This occurs when an instance call has too many checks.
-    // TODO(srdjan): Replace IC call with megamorphic call.
+    // This occurs when an instance call has too many checks, will be
+    // converted to megamorphic calls.
     return false;
   }
+  // Empty IC data.
   GrowableArray<intptr_t> class_ids(call->ic_data()->num_args_tested());
   ASSERT(call->ic_data()->num_args_tested() <= call->ArgumentCount());
   for (intptr_t i = 0; i < call->ic_data()->num_args_tested(); i++) {
-    intptr_t cid = call->PushArgumentAt(i)->value()->Type()->ToCid();
+    const intptr_t cid = call->PushArgumentAt(i)->value()->Type()->ToCid();
     class_ids.Add(cid);
   }
-  if (class_ids[0] != kDynamicCid) {
+  // We guess that comparison and binary operations typically
+  // have both arguments of the same cid. If only one argument's cid is known,
+  // assume the other argument has the same cid.
+  const Token::Kind op_kind = call->token_kind();
+  if (Token::IsRelationalOperator(op_kind) ||
+      Token::IsEqualityOperator(op_kind) ||
+      Token::IsBinaryOperator(op_kind)) {
+    // If left or right is a number -> make the other a number as well.
+    const intptr_t cid_0 = class_ids[0];
+    const intptr_t cid_1 = class_ids[1];
+    if ((cid_0 == kDynamicCid) && (IsNumberCid(cid_1))) {
+      class_ids[0] = cid_1;
+    } else if (IsNumberCid(cid_0) && (cid_1 == kDynamicCid)) {
+      class_ids[1] = cid_0;
+    }
+  }
+  if (NoneIsDynamic(class_ids)) {
     ArgumentsDescriptor args_desc(
         Array::Handle(ArgumentsDescriptor::New(call->ArgumentCount(),
                                                call->argument_names())));
     const Class& receiver_class = Class::Handle(
         Isolate::Current()->class_table()->At(class_ids[0]));
     const Function& function = Function::Handle(
         Resolver::ResolveDynamicForReceiverClass(
             receiver_class,
             call->function_name(),
             args_desc));
     if (function.IsNull()) {
       return false;
     }
-    // Create new ICData, do not modify the one attached to the instruction
-    // since it is attached to the assembly instruction itself.
-    // TODO(srdjan): Prevent modification of ICData object that is
-    // referenced in assembly code.
+
     ICData& ic_data = ICData::ZoneHandle(ICData::New(
         flow_graph_->parsed_function().function(),
         call->function_name(),
         Object::empty_array(),  // Dummy argument descriptor.
         call->deopt_id(),
         class_ids.length()));
     if (class_ids.length() > 1) {
       ic_data.AddCheck(class_ids, function);
     } else {
       ASSERT(class_ids.length() == 1);
@@ skipping 6758 matching lines @@
   SetValue(instr, non_constant_);
 }
 
 
 void ConstantPropagator::VisitUnboxInteger(UnboxIntegerInstr* instr) {
   // TODO(kmillikin): Handle unbox operation.
   SetValue(instr, non_constant_);
 }
 
 
-void ConstantPropagator::VisitBinaryMintOp(
-    BinaryMintOpInstr* instr) {
+void ConstantPropagator::VisitBinaryMintOp(BinaryMintOpInstr* instr) {
   HandleBinaryOp(instr, instr->op_kind(), *instr->left(), *instr->right());
 }
 
 
-void ConstantPropagator::VisitShiftMintOp(
-    ShiftMintOpInstr* instr) {
+void ConstantPropagator::VisitShiftMintOp(ShiftMintOpInstr* instr) {
   HandleBinaryOp(instr, instr->op_kind(), *instr->left(), *instr->right());
 }
 
 
-void ConstantPropagator::VisitUnaryMintOp(
-    UnaryMintOpInstr* instr) {
+void ConstantPropagator::VisitUnaryMintOp(UnaryMintOpInstr* instr) {
   // TODO(kmillikin): Handle unary operations.
   SetValue(instr, non_constant_);
 }
 
 
 void ConstantPropagator::VisitUnarySmiOp(UnarySmiOpInstr* instr) {
   const Object& value = instr->value()->definition()->constant_value();
   if (IsNonConstant(value)) {
     SetValue(instr, non_constant_);
   } else if (IsConstant(value)) {
@@ skipping 1113 matching lines @@
   }
 
   // Insert materializations at environment uses.
   for (intptr_t i = 0; i < exits.length(); i++) {
     CreateMaterializationAt(exits[i], alloc, alloc->cls(), *fields);
   }
 }
 
 
 }  // namespace dart