VM: Store edge counters in one per-function array.

runtime/vm/flow_graph_compiler_arm64.cc

 // Copyright (c) 2014, 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/globals.h"  // Needed here to get TARGET_ARCH_ARM64.
 #if defined(TARGET_ARCH_ARM64)
 
 #include "vm/flow_graph_compiler.h"
 
 #include "vm/ast_printer.h"
@@ skipping 1173 matching lines @@
       AddDeoptIndexAtCall(deopt_id_after, token_pos);
     } else {
       // Add deoptimization continuation point after the call and before the
       // arguments are removed.
       AddCurrentDescriptor(RawPcDescriptors::kDeopt, deopt_id_after, token_pos);
     }
   }
 }
 
 
-void FlowGraphCompiler::EmitEdgeCounter() {
+void FlowGraphCompiler::EmitEdgeCounter(intptr_t edge_id) {
   // We do not check for overflow when incrementing the edge counter.  The
   // function should normally be optimized long before the counter can
   // overflow; and though we do not reset the counters when we optimize or
   // deoptimize, there is a bound on the number of
   // optimization/deoptimization cycles we will attempt.
+  ASSERT(!edge_counters_array_.IsNull());
   ASSERT(assembler_->constant_pool_allowed());
-  const Array& counter = Array::ZoneHandle(zone(), Array::New(1, Heap::kOld));
-  counter.SetAt(0, Smi::Handle(zone(), Smi::New(0)));
   __ Comment("Edge counter");
-  __ LoadUniqueObject(R0, counter);
-  __ LoadFieldFromOffset(TMP, R0, Array::element_offset(0));
+  __ LoadObject(R0, edge_counters_array_);
+  __ LoadFieldFromOffset(TMP, R0, Array::element_offset(edge_id));
   __ add(TMP, TMP, Operand(Smi::RawValue(1)));
-  __ StoreFieldToOffset(TMP, R0, Array::element_offset(0));
+  __ StoreFieldToOffset(TMP, R0, Array::element_offset(edge_id));
 }
 
 
 void FlowGraphCompiler::EmitOptimizedInstanceCall(
     const StubEntry& stub_entry,
     const ICData& ic_data,
     intptr_t argument_count,
     intptr_t deopt_id,
     intptr_t token_pos,
     LocationSummary* locs) {
@@ skipping 614 matching lines @@
 void ParallelMoveResolver::RestoreFpuScratch(FpuRegister reg) {
   __ PopDouble(reg);
 }
 
 
 #undef __
 
 }  // namespace dart
 
 #endif  // defined TARGET_ARCH_ARM64