Pattern match on generated code to find edge counters.

runtime/vm/flow_graph_compiler_arm.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_ARM.
 #if defined(TARGET_ARCH_ARM)
 
 #include "vm/flow_graph_compiler.h"
 
 #include "vm/ast_printer.h"
@@ skipping 702 matching lines @@
   // type check runtime call is the checked value.
   __ Drop(6);
   __ Pop(R0);
 
   __ Bind(&is_assignable);
   // Restore instantiator (R2) and its type arguments (R1).
   __ PopList((1 << R1) | (1 << R2));
 }
 
 
-void FlowGraphCompiler::EmitInstructionPrologue(Instruction* instr) {
-  if (!is_optimizing()) {
-    if (FLAG_enable_type_checks && instr->IsAssertAssignable()) {
-      AssertAssignableInstr* assert = instr->AsAssertAssignable();
-      AddCurrentDescriptor(PcDescriptors::kDeopt,
-                           assert->deopt_id(),
-                           assert->token_pos());
-    } else if (instr->IsGuardField() ||
-               instr->CanBecomeDeoptimizationTarget()) {
-      AddCurrentDescriptor(PcDescriptors::kDeopt,
-                           instr->deopt_id(),
-                           Scanner::kDummyTokenIndex);
-    }
-    AllocateRegistersLocally(instr);
-  } else if (instr->MayThrow()  &&
-             (CurrentTryIndex() != CatchClauseNode::kInvalidTryIndex)) {
-    // Optimized try-block: Sync locals to fixed stack locations.
-    EmitTrySync(instr, CurrentTryIndex());
-  }
-}
-
-
 void FlowGraphCompiler::EmitTrySyncMove(intptr_t dest_offset,
                                         Location loc,
                                         bool* push_emitted) {
   if (loc.IsConstant()) {
     if (!*push_emitted) {
       __ Push(R0);
       *push_emitted = true;
     }
     __ LoadObject(R0, loc.constant());
     __ StoreToOffset(kWord, R0, FP, dest_offset);
@@ skipping 513 matching lines @@
       // Add deoptimization continuation point after the call and before the
       // arguments are removed.
       AddCurrentDescriptor(PcDescriptors::kDeopt,
                            deopt_id_after,
                            token_pos);
     }
   }
 }
 
 
+void FlowGraphCompiler::EmitEdgeCounter() {
+  // 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.
+  const Array& counter = Array::ZoneHandle(Array::New(1, Heap::kOld));
+  counter.SetAt(0, Smi::Handle(Smi::New(0)));
+  __ Comment("Edge counter");
+  __ LoadObject(R0, counter);
+  __ ldr(IP, FieldAddress(R0, Array::element_offset(0)));
+  __ adds(IP, IP, ShifterOperand(Smi::RawValue(1)));
+  __ str(IP, FieldAddress(R0, Array::element_offset(0)));
+}
+
+
 void FlowGraphCompiler::EmitOptimizedInstanceCall(
     ExternalLabel* target_label,
     const ICData& ic_data,
     intptr_t argument_count,
     intptr_t deopt_id,
     intptr_t token_pos,
     LocationSummary* locs) {
   // Each ICData propagated from unoptimized to optimized code contains the
   // function that corresponds to the Dart function of that IC call. Due
   // to inlining in optimized code, that function may not correspond to the
@@ skipping 629 matching lines @@
   DRegister dreg = EvenDRegisterOf(reg);
   __ vldrd(dreg, Address(SP, kDoubleSize, Address::PostIndex));
 }
 
 
 #undef __
 
 }  // namespace dart
 
 #endif  // defined TARGET_ARCH_ARM