Fix performance regression on Tracer: recognize _doublePow in Math.

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 1704 matching lines @@
 void FlowGraphOptimizer::ReplaceWithMathCFunction(
   InstanceCallInstr* call,
   MethodRecognizer::Kind recognized_kind) {
   AddReceiverCheck(call);
   ZoneGrowableArray<Value*>* args =
       new ZoneGrowableArray<Value*>(call->ArgumentCount());
   for (intptr_t i = 0; i < call->ArgumentCount(); i++) {
     args->Add(new Value(call->ArgumentAt(i)));
   }
   InvokeMathCFunctionInstr* invoke =
-      new InvokeMathCFunctionInstr(args, call, recognized_kind);
+      new InvokeMathCFunctionInstr(args, call->deopt_id(), recognized_kind);
   ReplaceCall(call, invoke);
 }
 
 
 static bool IsSupportedByteArrayViewCid(intptr_t cid) {
   switch (cid) {
     case kTypedDataInt8ArrayCid:
     case kTypedDataUint8ArrayCid:
     case kExternalTypedDataUint8ArrayCid:
     case kTypedDataUint8ClampedArrayCid:
@@ skipping 118 matching lines @@
           // Do not repeatedly deoptimize because result didn't fit into Smi.
           d2i_instr = new DoubleToIntegerInstr(new Value(input), call);
         } else {
           // Optimistically assume result fits into Smi.
           d2i_instr = new DoubleToSmiInstr(new Value(input), call->deopt_id());
         }
         ReplaceCall(call, d2i_instr);
         return true;
       }
       case MethodRecognizer::kDoubleMod:
-      case MethodRecognizer::kDoublePow:
       case MethodRecognizer::kDoubleRound:
         ReplaceWithMathCFunction(call, recognized_kind);
         return true;
       case MethodRecognizer::kDoubleTruncate:
       case MethodRecognizer::kDoubleFloor:
       case MethodRecognizer::kDoubleCeil:
         if (!CPUFeatures::double_truncate_round_supported()) {
           ReplaceWithMathCFunction(call, recognized_kind);
         } else {
           AddReceiverCheck(call);
@@ skipping 887 matching lines @@
                       call->env(),
                       call);
         AddCheckClass(min_max->right()->definition(),
                       unary_checks,
                       call->deopt_id(),
                       call->env(),
                       call);
         ReplaceCall(call, min_max);
       }
     }
+  } else if (recognized_kind == MethodRecognizer::kMathDoublePow) {
+    // We know that first argument is double, the second is num.
+    // InvokeMathCFunctionInstr requires unboxed doubles. UnboxDouble
+    // instructions contain type checks and conversions to double.
+    ZoneGrowableArray<Value*>* args =
+        new ZoneGrowableArray<Value*>(call->ArgumentCount());
+    for (intptr_t i = 0; i < call->ArgumentCount(); i++) {
+      args->Add(new Value(call->ArgumentAt(i)));
+    }
+    InvokeMathCFunctionInstr* invoke =
+        new InvokeMathCFunctionInstr(args, call->deopt_id(), recognized_kind);
+    ReplaceCall(call, invoke);
   }
 }
 
 
 bool FlowGraphOptimizer::TryInlineInstanceSetter(InstanceCallInstr* instr,
                                                  const ICData& unary_ic_data) {
   ASSERT((unary_ic_data.NumberOfChecks() > 0) &&
       (unary_ic_data.num_args_tested() == 1));
   if (FLAG_enable_type_checks) {
     // TODO(srdjan): Add assignable check node if --enable_type_checks.
@@ skipping 4722 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