Address perf regression by using the expected frame layout when traversing frames in the code gener…

runtime/vm/code_generator.cc

Index: runtime/vm/code_generator.cc
===================================================================
--- runtime/vm/code_generator.cc	(revision 6959)
+++ runtime/vm/code_generator.cc	(working copy)
@@ -33,6 +33,23 @@
 DECLARE_FLAG(int, deoptimization_counter_threshold);
 
 
+static StackFrame* GetTopDartFrame(
+    StackFrameIterator* iterator, bool has_stub_frame) {

[srdjan, 2012/04/25 19:31:13]

You could move the StackFrameIterator in here, instead of passing it in.

[siva, 2012/04/25 20:08:49]

Not really because the caller_frame that is returned has state in the iterator
and if the iterator is destroyed then the state is lost.
If I move it here the iterator destructor will run as we return from this
function.

On 2012/04/25 19:31:13, srdjan wrote:

+  // When runtime calls are made from dart code we assume that we will
+  // always have an exit frame and an optional stub frame before we hit
+  // the first dart frame.
+  StackFrame* exit_frame = iterator->NextFrame();
+  ASSERT(exit_frame != NULL && exit_frame->IsExitFrame());
+  if (has_stub_frame) {
+    StackFrame* stub_frame = iterator->NextFrame();
+    ASSERT(stub_frame != NULL && stub_frame->IsStubFrame());
+  }
+  StackFrame* caller_frame = iterator->NextFrame();
+  ASSERT(caller_frame != NULL && caller_frame->IsDartFrame());
+  return caller_frame;
+}
+
+
 bool CodeGenerator::CanOptimize() {
   return
       !FLAG_report_usage_count &&
@@ -343,9 +360,8 @@
                 String::Handle(instantiated_type.Name()).ToCString(),
                 String::Handle(type.Name()).ToCString());
     }
-    DartFrameIterator iterator;
-    StackFrame* caller_frame = iterator.NextFrame();
-    ASSERT(caller_frame != NULL && caller_frame->IsDartFrame());
+    StackFrameIterator iterator(StackFrameIterator::kDontValidateFrames);
+    StackFrame* caller_frame = GetTopDartFrame(&iterator, false);
     const Function& function = Function::Handle(
         caller_frame->LookupDartFunction());
     OS::Print(" -> Function %s\n", function.ToFullyQualifiedCString());
@@ -362,9 +378,8 @@
   // Update cache: add class of instance and result.
   if (type.IsInstantiated() &&
       !Class::Handle(type.type_class()).HasTypeArguments()) {
-    DartFrameIterator iterator;
-    StackFrame* caller_frame = iterator.NextFrame();
-    ASSERT(caller_frame != NULL && caller_frame->IsDartFrame());
+    StackFrameIterator iterator(StackFrameIterator::kDontValidateFrames);
+    StackFrame* caller_frame = GetTopDartFrame(&iterator, false);
     const Code& code = Code::Handle(caller_frame->LookupDartCode());
     ASSERT(!code.IsNull());
     uword loc = code.GetTypeTestAtNodeId(node_id);
@@ -456,9 +471,8 @@
                 dst_name.ToCString(),
                 String::Handle(dst_type.Name()).ToCString());
     }
-    DartFrameIterator iterator;
-    StackFrame* caller_frame = iterator.NextFrame();
-    ASSERT(caller_frame != NULL && caller_frame->IsDartFrame());
+    StackFrameIterator iterator(StackFrameIterator::kDontValidateFrames);
+    StackFrame* caller_frame = GetTopDartFrame(&iterator, false);
     const Function& function = Function::Handle(
         caller_frame->LookupDartFunction());
     OS::Print(" -> Function %s\n", function.ToFullyQualifiedCString());
@@ -486,9 +500,8 @@
   // Update cache: add class of instance and result.
   if (dst_type.IsInstantiated() &&
       !Class::Handle(dst_type.type_class()).HasTypeArguments()) {
-    DartFrameIterator iterator;
-    StackFrame* caller_frame = iterator.NextFrame();
-    ASSERT(caller_frame != NULL && caller_frame->IsDartFrame());
+    StackFrameIterator iterator(StackFrameIterator::kDontValidateFrames);
+    StackFrame* caller_frame = GetTopDartFrame(&iterator, false);
     const Code& code = Code::Handle(caller_frame->LookupDartCode());
     ASSERT(!code.IsNull());
     uword loc = code.GetTypeTestAtNodeId(node_id);
@@ -647,9 +660,8 @@
   // This function is called after successful resolving and compilation of
   // the target method.
   ASSERT(arguments.Count() == kPatchStaticCallRuntimeEntry.argument_count());
-  DartFrameIterator iterator;
-  StackFrame* caller_frame = iterator.NextFrame();
-  ASSERT(caller_frame != NULL && caller_frame->IsDartFrame());
+  StackFrameIterator iterator(StackFrameIterator::kDontValidateFrames);
+  StackFrame* caller_frame = GetTopDartFrame(&iterator, true);
   uword target = 0;
   Function& target_function = Function::Handle();
   CodePatcher::GetStaticCallAt(caller_frame->pc(), &target_function, &target);
@@ -672,13 +684,12 @@
 // Only the number of named arguments is checked, but not the actual names.
 RawCode* ResolveCompileInstanceCallTarget(Isolate* isolate,
                                           const Instance& receiver) {
-  DartFrameIterator iterator;
-  StackFrame* caller_frame = iterator.NextFrame();
-  ASSERT(caller_frame != NULL && caller_frame->IsDartFrame());
   int num_arguments = -1;
   int num_named_arguments = -1;
   uword target = 0;
   String& function_name = String::Handle();
+  StackFrameIterator iterator(StackFrameIterator::kDontValidateFrames);
+  StackFrame* caller_frame = GetTopDartFrame(&iterator, true);
   CodePatcher::GetInstanceCallAt(caller_frame->pc(),
                                  &function_name,
                                  &num_arguments,
@@ -816,9 +827,8 @@
     }
     return target_function.raw();
   }
-  DartFrameIterator iterator;
-  StackFrame* caller_frame = iterator.NextFrame();
-  ASSERT(caller_frame != NULL && caller_frame->IsDartFrame());
+  StackFrameIterator iterator(StackFrameIterator::kDontValidateFrames);
+  StackFrame* caller_frame = GetTopDartFrame(&iterator, true);
   ICData& ic_data = ICData::Handle(
       CodePatcher::GetInstanceCallIcDataAt(caller_frame->pc()));
 #if defined(DEBUG)
@@ -1284,9 +1294,8 @@
 DEFINE_RUNTIME_ENTRY(Deoptimize, 1) {
   ASSERT(arguments.Count() == kDeoptimizeRuntimeEntry.argument_count());
   const Smi& deoptimization_reason_id = Smi::CheckedHandle(arguments.At(0));
-  DartFrameIterator iterator;
-  StackFrame* caller_frame = iterator.NextFrame();
-  ASSERT(caller_frame != NULL && caller_frame->IsDartFrame());
+  StackFrameIterator iterator(StackFrameIterator::kDontValidateFrames);
+  StackFrame* caller_frame = GetTopDartFrame(&iterator, true);
   const Code& optimized_code = Code::Handle(caller_frame->LookupDartCode());
   const Function& function = Function::Handle(optimized_code.function());
   ASSERT(!function.IsNull());