Speed up function deoptimization by avoiding quadratic pass over optimized function list.

R=danno@chromium.org
BUG=155270

Review URL: https://chromiumcodereview.appspot.com/11189091

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@12780 ce2b1a6d-e550-0410-aec6-3dcde31c8c00

src/arm/deoptimizer-arm.cc

@@ -104,19 +104,7 @@ void Deoptimizer::DeoptimizeFunction(JSFunction* function) {
   // ignore all slots that might have been recorded on it.
   isolate->heap()->mark_compact_collector()->InvalidateCode(code);
 
-  // Iterate over all the functions which share the same code object
-  // and make them use unoptimized version.
-  Context* context = function->context()->native_context();
-  Object* element = context->get(Context::OPTIMIZED_FUNCTIONS_LIST);
-  SharedFunctionInfo* shared = function->shared();
-  while (!element->IsUndefined()) {
-    JSFunction* func = JSFunction::cast(element);
-    // Grab element before code replacement as ReplaceCode alters the list.
-    element = func->next_function_link();
-    if (func->code() == code) {
-      func->ReplaceCode(shared->code());
-    }
-  }
+  ReplaceCodeForRelatedFunctions(function, code);
 
   if (FLAG_trace_deopt) {
     PrintF("[forced deoptimization: ");

src/deoptimizer.cc

@@ -1443,6 +1443,54 @@ void Deoptimizer::RemoveDeoptimizingCode(Code* code) {
 }
 
 
+static Object* CutOutRelatedFunctionsList(Context* context,
+                                          Code* code,
+                                          Object* undefined) {
+  Object* result_list_head = undefined;
+  Object* head;
+  Object* current;
+  current = head = context->get(Context::OPTIMIZED_FUNCTIONS_LIST);
+  JSFunction* prev = NULL;
+  while (current != undefined) {
+    JSFunction* func = JSFunction::cast(current);
+    current = func->next_function_link();
+    if (func->code() == code) {
+      func->set_next_function_link(result_list_head);
+      result_list_head = func;
+      if (prev) {
+        prev->set_next_function_link(current);
+      } else {
+        head = current;
+      }
+    } else {
+      prev = func;
+    }
+  }
+  if (head != context->get(Context::OPTIMIZED_FUNCTIONS_LIST)) {
+    context->set(Context::OPTIMIZED_FUNCTIONS_LIST, head);
+  }
+  return result_list_head;
+}
+
+
+void Deoptimizer::ReplaceCodeForRelatedFunctions(JSFunction* function,
+                                                 Code* code) {
+  Context* context = function->context()->native_context();
+
+  SharedFunctionInfo* shared = function->shared();
+
+  Object* undefined = Isolate::Current()->heap()->undefined_value();
+  Object* current = CutOutRelatedFunctionsList(context, code, undefined);
+
+  while (current != undefined) {
+    JSFunction* func = JSFunction::cast(current);
+    current = func->next_function_link();
+    func->set_code(shared->code());
+    func->set_next_function_link(undefined);
+  }
+}
+
+
 FrameDescription::FrameDescription(uint32_t frame_size,
                                    JSFunction* function)
     : frame_size_(frame_size),

src/deoptimizer.h

@@ -166,6 +166,10 @@ class Deoptimizer : public Malloced {
   // execution returns.
   static void DeoptimizeFunction(JSFunction* function);
 
+  // Iterate over all the functions which share the same code object
+  // and make them use unoptimized version.
+  static void ReplaceCodeForRelatedFunctions(JSFunction* function, Code* code);
+
   // Deoptimize all functions in the heap.
   static void DeoptimizeAll();
 

src/ia32/deoptimizer-ia32.cc

@@ -198,19 +198,7 @@ void Deoptimizer::DeoptimizeFunction(JSFunction* function) {
   // ignore all slots that might have been recorded on it.
   isolate->heap()->mark_compact_collector()->InvalidateCode(code);
 
-  // Iterate over all the functions which share the same code object
-  // and make them use unoptimized version.
-  Context* context = function->context()->native_context();
-  Object* element = context->get(Context::OPTIMIZED_FUNCTIONS_LIST);
-  SharedFunctionInfo* shared = function->shared();
-  while (!element->IsUndefined()) {
-    JSFunction* func = JSFunction::cast(element);
-    // Grab element before code replacement as ReplaceCode alters the list.
-    element = func->next_function_link();
-    if (func->code() == code) {
-      func->ReplaceCode(shared->code());
-    }
-  }
+  ReplaceCodeForRelatedFunctions(function, code);
 
   if (FLAG_trace_deopt) {
     PrintF("[forced deoptimization: ");

src/mips/deoptimizer-mips.cc

@@ -100,19 +100,7 @@ void Deoptimizer::DeoptimizeFunction(JSFunction* function) {
   // ignore all slots that might have been recorded on it.
   isolate->heap()->mark_compact_collector()->InvalidateCode(code);
 
-  // Iterate over all the functions which share the same code object
-  // and make them use unoptimized version.
-  Context* context = function->context()->native_context();
-  Object* element = context->get(Context::OPTIMIZED_FUNCTIONS_LIST);
-  SharedFunctionInfo* shared = function->shared();
-  while (!element->IsUndefined()) {
-    JSFunction* func = JSFunction::cast(element);
-    // Grab element before code replacement as ReplaceCode alters the list.
-    element = func->next_function_link();
-    if (func->code() == code) {
-      func->ReplaceCode(shared->code());
-    }
-  }
+  ReplaceCodeForRelatedFunctions(function, code);
 
   if (FLAG_trace_deopt) {
     PrintF("[forced deoptimization: ");

src/x64/deoptimizer-x64.cc

@@ -104,19 +104,7 @@ void Deoptimizer::DeoptimizeFunction(JSFunction* function) {
   // ignore all slots that might have been recorded on it.
   isolate->heap()->mark_compact_collector()->InvalidateCode(code);
 
-  // Iterate over all the functions which share the same code object
-  // and make them use unoptimized version.
-  Context* context = function->context()->native_context();
-  Object* element = context->get(Context::OPTIMIZED_FUNCTIONS_LIST);
-  SharedFunctionInfo* shared = function->shared();
-  while (!element->IsUndefined()) {
-    JSFunction* func = JSFunction::cast(element);
-    // Grab element before code replacement as ReplaceCode alters the list.
-    element = func->next_function_link();
-    if (func->code() == code) {
-      func->ReplaceCode(shared->code());
-    }
-  }
+  ReplaceCodeForRelatedFunctions(function, code);
 
   if (FLAG_trace_deopt) {
     PrintF("[forced deoptimization: ");