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

runtime/vm/flow_graph_compiler_x64.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/globals.h"  // Needed here to get TARGET_ARCH_X64.
 #if defined(TARGET_ARCH_X64)
 
 #include "vm/flow_graph_compiler.h"
 
 #include "vm/ast_printer.h"
@@ skipping 1192 matching lines @@
   __ LoadObject(RBX, ic_data);
   GenerateDartCall(deopt_id,
                    token_pos,
                    *stub_entry,
                    RawPcDescriptors::kUnoptStaticCall,
                    locs);
   __ Drop(argument_count, RCX);
 }
 
 
-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(RAX, counter);
-  intptr_t increment_start = assembler_->CodeSize();
-  __ IncrementSmiField(FieldAddress(RAX, Array::element_offset(0)), 1);
-  int32_t size = assembler_->CodeSize() - increment_start;
-  if (isolate()->edge_counter_increment_size() == -1) {
-    isolate()->set_edge_counter_increment_size(size);
-  } else {
-    ASSERT(size == isolate()->edge_counter_increment_size());
-  }
+  __ LoadObject(RAX, edge_counters_array_);
+  __ IncrementSmiField(FieldAddress(RAX, Array::element_offset(edge_id)), 1);
 }
 
 
-int32_t FlowGraphCompiler::EdgeCounterIncrementSizeInBytes() {
-  const int32_t size = Isolate::Current()->edge_counter_increment_size();
-  ASSERT(size != -1);
-  return size;
-}
-
-
 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) {
   ASSERT(Array::Handle(zone(), ic_data.arguments_descriptor()).Length() > 0);
   // Each ICData propagated from unoptimized to optimized code contains the
   // function that corresponds to the Dart function of that IC call. Due
@@ skipping 513 matching lines @@
   __ movups(reg, Address(RSP, 0));
   __ AddImmediate(RSP, Immediate(kFpuRegisterSize));
 }
 
 
 #undef __
 
 }  // namespace dart
 
 #endif  // defined TARGET_ARCH_X64