Optimize equuality operation for two Boolean arguments.

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 574 matching lines @@
   if (ic_data.NumberOfChecks() == 1) {
     return ic_data.HasReceiverClassId(kSmiCid)
         || ic_data.HasReceiverClassId(kMintCid);
   }
   return (ic_data.NumberOfChecks() == 2)
       && ic_data.HasReceiverClassId(kSmiCid)
       && ic_data.HasReceiverClassId(kMintCid);
 }
 
 
-static bool HasOnlyTwoSmis(const ICData& ic_data) {
+static bool HasOnlyTwoOf(const ICData& ic_data, intptr_t cid) {
   return (ic_data.NumberOfChecks() == 1) &&
-      ICDataHasReceiverArgumentClassIds(ic_data, kSmiCid, kSmiCid);
-}
-
-static bool HasOnlyTwoFloat32x4s(const ICData& ic_data) {
-  return (ic_data.NumberOfChecks() == 1) &&
-      ICDataHasReceiverArgumentClassIds(ic_data, kFloat32x4Cid, kFloat32x4Cid);
-}
-
-static bool HasOnlyTwoUint32x4s(const ICData& ic_data) {
-  return (ic_data.NumberOfChecks() == 1) &&
-      ICDataHasReceiverArgumentClassIds(ic_data, kUint32x4Cid, kUint32x4Cid);
+      ICDataHasReceiverArgumentClassIds(ic_data, cid, cid);
 }
 
 // Returns false if the ICData contains anything other than the 4 combinations
 // of Mint and Smi for the receiver and argument classes.
 static bool HasTwoMintOrSmi(const ICData& ic_data) {
   GrowableArray<intptr_t> class_ids(2);
   class_ids.Add(kSmiCid);
   class_ids.Add(kMintCid);
   return ICDataHasOnlyReceiverArgumentClassIds(ic_data, class_ids, class_ids);
 }
@@ skipping 405 matching lines @@
 
 
 bool FlowGraphOptimizer::TryReplaceWithBinaryOp(InstanceCallInstr* call,
                                                 Token::Kind op_kind) {
   intptr_t operands_type = kIllegalCid;
   ASSERT(call->HasICData());
   const ICData& ic_data = *call->ic_data();
   switch (op_kind) {
     case Token::kADD:
     case Token::kSUB:
-      if (HasOnlyTwoSmis(ic_data)) {
+      if (HasOnlyTwoOf(ic_data, kSmiCid)) {
         // Don't generate smi code if the IC data is marked because
         // of an overflow.
         operands_type = (ic_data.deopt_reason() == kDeoptBinarySmiOp)
             ? kMintCid
             : kSmiCid;
       } else if (HasTwoMintOrSmi(ic_data) &&
                  FlowGraphCompiler::SupportsUnboxedMints()) {
         // Don't generate mint code if the IC data is marked because of an
         // overflow.
         if (ic_data.deopt_reason() == kDeoptBinaryMintOp) return false;
         operands_type = kMintCid;
       } else if (ShouldSpecializeForDouble(ic_data)) {
         operands_type = kDoubleCid;
-      } else if (HasOnlyTwoFloat32x4s(ic_data)) {
+      } else if (HasOnlyTwoOf(ic_data, kFloat32x4Cid)) {
         operands_type = kFloat32x4Cid;
       } else {
         return false;
       }
       break;
     case Token::kMUL:
-      if (HasOnlyTwoSmis(ic_data)) {
+      if (HasOnlyTwoOf(ic_data, kSmiCid)) {
         // Don't generate smi code if the IC data is marked because of an
         // overflow.
         // TODO(fschneider): Add unboxed mint multiplication.
         if (ic_data.deopt_reason() == kDeoptBinarySmiOp) return false;
         operands_type = kSmiCid;
       } else if (ShouldSpecializeForDouble(ic_data)) {
         operands_type = kDoubleCid;
-      } else if (HasOnlyTwoFloat32x4s(ic_data)) {
+      } else if (HasOnlyTwoOf(ic_data, kFloat32x4Cid)) {
         operands_type = kFloat32x4Cid;
       } else {
         return false;
       }
       break;
     case Token::kDIV:
-      if (ShouldSpecializeForDouble(ic_data) || HasOnlyTwoSmis(ic_data)) {
+      if (ShouldSpecializeForDouble(ic_data) ||
+          HasOnlyTwoOf(ic_data, kSmiCid)) {
         operands_type = kDoubleCid;
-      } else if (HasOnlyTwoFloat32x4s(ic_data)) {
+      } else if (HasOnlyTwoOf(ic_data, kFloat32x4Cid)) {
         operands_type = kFloat32x4Cid;
       } else {
         return false;
       }
       break;
     case Token::kMOD:
-      if (HasOnlyTwoSmis(ic_data)) {
+      if (HasOnlyTwoOf(ic_data, kSmiCid)) {
         operands_type = kSmiCid;
       } else {
         return false;
       }
       break;
     case Token::kBIT_AND:
     case Token::kBIT_OR:
     case Token::kBIT_XOR:
-      if (HasOnlyTwoSmis(ic_data)) {
+      if (HasOnlyTwoOf(ic_data, kSmiCid)) {
         operands_type = kSmiCid;
       } else if (HasTwoMintOrSmi(ic_data)) {
         operands_type = kMintCid;
-      } else if (HasOnlyTwoUint32x4s(ic_data)) {
+      } else if (HasOnlyTwoOf(ic_data, kUint32x4Cid)) {
         operands_type = kUint32x4Cid;
       } else {
         return false;
       }
       break;
     case Token::kSHR:
     case Token::kSHL:
-      if (HasOnlyTwoSmis(ic_data)) {
+      if (HasOnlyTwoOf(ic_data, kSmiCid)) {
         // Left shift may overflow from smi into mint or big ints.
         // Don't generate smi code if the IC data is marked because
         // of an overflow.
         if (ic_data.deopt_reason() == kDeoptShiftMintOp) return false;
         operands_type = (ic_data.deopt_reason() == kDeoptBinarySmiOp)
             ? kMintCid
             : kSmiCid;
       } else if (HasTwoMintOrSmi(ic_data) &&
                  HasOnlyOneSmi(ICData::Handle(
                      ic_data.AsUnaryClassChecksForArgNr(1)))) {
         // Don't generate mint code if the IC data is marked because of an
         // overflow.
         if (ic_data.deopt_reason() == kDeoptShiftMintOp) return false;
         // Check for smi/mint << smi or smi/mint >> smi.
         operands_type = kMintCid;
       } else {
         return false;
       }
       break;
     case Token::kTRUNCDIV:
-      if (HasOnlyTwoSmis(ic_data)) {
+      if (HasOnlyTwoOf(ic_data, kSmiCid)) {
         if (ic_data.deopt_reason() == kDeoptBinarySmiOp) return false;
         operands_type = kSmiCid;
       } else {
         return false;
       }
       break;
     default:
       UNREACHABLE();
   }
 
@@ skipping 1639 matching lines @@
 
 
 static bool SmiFitsInDouble() { return kSmiBits < 53; }
 
 
 void FlowGraphOptimizer::HandleComparison(ComparisonInstr* comp,
                                           const ICData& ic_data,
                                           Instruction* current_instruction) {
   ASSERT(ic_data.num_args_tested() == 2);
   ASSERT(comp->operation_cid() == kIllegalCid);
-  if (HasOnlyTwoSmis(ic_data)) {
+  if (HasOnlyTwoOf(ic_data, kSmiCid)) {
     InsertBefore(current_instruction,
                  new CheckSmiInstr(comp->left()->Copy(), comp->deopt_id()),
                  current_instruction->env(),
                  Definition::kEffect);
     InsertBefore(current_instruction,
                  new CheckSmiInstr(comp->right()->Copy(), comp->deopt_id()),
                  current_instruction->env(),
                  Definition::kEffect);
     comp->set_operation_cid(kSmiCid);
   } else if (HasTwoMintOrSmi(ic_data) &&
@@ skipping 93 matching lines @@
                                strict_kind,
                                compare->left()->CopyWithType(),
                                compare->right()->CopyWithType());
     current_instruction->ReplaceWith(strict_comp, current_iterator());
     return true;
   }
   return false;
 }
 
 
+// Returns true if we converted EqualityCompare to StrictCompare.
+template <typename T>
+bool FlowGraphOptimizer::StrictifyEqualityCompareWithICData(
+    EqualityCompareInstr* compare,
+    const ICData& unary_ic_data,
+    T current_instruction) {
+  ASSERT(unary_ic_data.num_args_tested() == 1);
+  if (unary_ic_data.NumberOfChecks() <= FLAG_max_polymorphic_checks) {
+    // If possible classes do not override Object's equality then replace
+    // with strict equality.
+    Function& target = Function::Handle();
+    Class& targets_class = Class::Handle();
+    for (intptr_t i = 0; i < unary_ic_data.NumberOfChecks(); i++) {
+      intptr_t cid = kIllegalCid;
+      unary_ic_data.GetOneClassCheckAt(i, &cid, &target);
+      targets_class = target.Owner();
+      if (targets_class.id() != kInstanceCid) {
+        // Overriden equality operator.
+        return false;
+      }
+    }
+    AddCheckClass(compare->left()->definition(),
+                  unary_ic_data,
+                  compare->deopt_id(),
+                  current_instruction->env(),
+                  current_instruction);
+    ASSERT((compare->kind() == Token::kEQ) || (compare->kind() == Token::kNE));
+    Token::Kind strict_kind = (compare->kind() == Token::kEQ) ?
+        Token::kEQ_STRICT : Token::kNE_STRICT;
+    StrictCompareInstr* strict_comp =
+        new StrictCompareInstr(compare->token_pos(),
+                               strict_kind,
+                               compare->left()->Copy(),
+                               compare->right()->Copy());
+    current_instruction->ReplaceWith(strict_comp, current_iterator());
+    return true;
+  }
+  return false;
+}
+
+
 template <typename T>
 void FlowGraphOptimizer::HandleEqualityCompare(EqualityCompareInstr* comp,
                                                T current_instruction) {
   if (StrictifyEqualityCompare(comp, current_instruction)) {
+    // Based on input types, equality converted to strict-equality.
     return;
   }
 
   if (!comp->HasICData() || (comp->ic_data()->NumberOfChecks() == 0)) {
     return;
   }
 
   const ICData& ic_data = *comp->ic_data();
   HandleComparison(comp, ic_data, current_instruction);
 
   if (comp->operation_cid() != kIllegalCid) {
     // Done.
     return;
   }
 
+  const ICData& unary_checks_0 =
+      ICData::ZoneHandle(comp->ic_data()->AsUnaryClassChecks());
+  if (StrictifyEqualityCompareWithICData(
+        comp, unary_checks_0, current_instruction)) {
+    // Based on ICData, equality converted to strict-equality.
+    return;
+  }
+
   // Check if ICDData contains checks with Smi/Null combinations. In that case
   // we can still emit the optimized Smi equality operation but need to add
   // checks for null or Smi.
   // TODO(srdjan): Add it for Double and Mint.
   GrowableArray<intptr_t> smi_or_null(2);
   smi_or_null.Add(kSmiCid);
   smi_or_null.Add(kNullCid);
   if (ICDataHasOnlyReceiverArgumentClassIds(ic_data,
                                             smi_or_null,
                                             smi_or_null)) {
-    const ICData& unary_checks_0 =
-        ICData::ZoneHandle(comp->ic_data()->AsUnaryClassChecks());
     AddCheckClass(comp->left()->definition(),
                   unary_checks_0,
                   comp->deopt_id(),
                   current_instruction->env(),
                   current_instruction);
 
     const ICData& unary_checks_1 =
         ICData::ZoneHandle(comp->ic_data()->AsUnaryClassChecksForArgNr(1));
     AddCheckClass(comp->right()->definition(),
                   unary_checks_1,
@@ skipping 4431 matching lines @@
 
   // Insert materializations at environment uses.
   const Class& cls = Class::Handle(alloc->constructor().Owner());
   for (intptr_t i = 0; i < exits.length(); i++) {
     CreateMaterializationAt(exits[i], alloc, cls, *fields);
   }
 }
 
 
 }  // namespace dart