Pattern match on generated code to find edge counters.

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 706 matching lines @@
   // type check runtime call is the checked value.
   __ Drop(6);
   __ popq(RAX);
 
   __ Bind(&is_assignable);
   __ popq(RDX);  // Remove pushed instantiator type arguments.
   __ popq(RCX);  // Remove pushed instantiator.
 }
 
 
-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) {
   const Address dest(RBP, dest_offset);
   if (loc.IsConstant()) {
     if (!*push_emitted) {
       __ pushq(RAX);
       *push_emitted = true;
     }
     __ LoadObject(RAX, loc.constant(), PP);
@@ skipping 592 matching lines @@
   __ LoadObject(RBX, ic_data, PP);
   GenerateDartCall(deopt_id,
                    token_pos,
                    &target_label,
                    PcDescriptors::kUnoptStaticCall,
                    locs);
   __ Drop(argument_count);
 }
 
 
+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(RAX, counter, PP);
+  __ AddImmediate(FieldAddress(RAX, Array::element_offset(0)),
+                  Immediate(Smi::RawValue(1)), PP);
+}
+
+
 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 570 matching lines @@
   __ movups(reg, Address(RSP, 0));
   __ AddImmediate(RSP, Immediate(kFpuRegisterSize), PP);
 }
 
 
 #undef __
 
 }  // namespace dart
 
 #endif  // defined TARGET_ARCH_X64