Fix sharing of literal boilerplates for optimized code.

This makes sure the literal boilerplates array is correctly shared
together with optimized code when caching of optimized code is enabled.
It also enabled said caching by default again.

R=ulan@chromium.org
BUG=v8:2193
TEST=mjsunit/regress/regress-2193

Review URL: https://chromiumcodereview.appspot.com/10649008

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@11911 ce2b1a6d-e550-0410-aec6-3dcde31c8c00

src/compiler.cc

@@ -623,17 +623,15 @@ bool Compiler::CompileLazy(CompilationInfo* info) {
     Handle<JSFunction> function = info->closure();
     ASSERT(!function.is_null());
     Handle<Context> global_context(function->context()->global_context());
-    int index = function->shared()->SearchOptimizedCodeMap(*global_context);
+    int index = shared->SearchOptimizedCodeMap(*global_context);
     if (index > 0) {
       if (FLAG_trace_opt) {
-        PrintF("  [Found optimized code for");
+        PrintF("[found optimized code for: ");
         function->PrintName();
-        PrintF("\n");
+        PrintF(" / %" V8PRIxPTR "]\n", reinterpret_cast<intptr_t>(*function));
       }
-      Code* code = Code::cast(
-          FixedArray::cast(shared->optimized_code_map())->get(index));
-      ASSERT(code != NULL);
-      function->ReplaceCode(code);
+      // Caching of optimized code enabled and optimized code found.
+      shared->InstallFromOptimizedCodeMap(*function, index);
       return true;
     }
   }
@@ -672,20 +670,8 @@ bool Compiler::CompileLazy(CompilationInfo* info) {
         if (FLAG_cache_optimized_code &&
             code->kind() == Code::OPTIMIZED_FUNCTION) {
           Handle<SharedFunctionInfo> shared(function->shared());
+          Handle<FixedArray> literals(function->literals());
           Handle<Context> global_context(function->context()->global_context());
-
-          // Create literals array that will be shared for this global context.
-          int number_of_literals = shared->num_literals();
-          Handle<FixedArray> literals =
-              isolate->factory()->NewFixedArray(number_of_literals);
-          if (number_of_literals > 0) {
-            // Store the object, regexp and array functions in the literals
-            // array prefix.  These functions will be used when creating
-            // object, regexp and array literals in this function.
-            literals->set(JSFunction::kLiteralGlobalContextIndex,
-                          function->context()->global_context());
-          }
-
           SharedFunctionInfo::AddToOptimizedCodeMap(
               shared, global_context, code, literals);
         }

src/factory.cc

@@ -555,40 +555,23 @@ Handle<JSFunction> Factory::NewFunctionFromSharedFunctionInfo(
 
   result->set_context(*context);
 
-  int index = FLAG_cache_optimized_code
-      ? function_info->SearchOptimizedCodeMap(context->global_context())
-      : -1;
-  if (!function_info->bound()) {
-    if (index > 0) {
-      FixedArray* code_map =
-          FixedArray::cast(function_info->optimized_code_map());
-      FixedArray* cached_literals = FixedArray::cast(code_map->get(index + 1));
-      ASSERT(cached_literals != NULL);
-      ASSERT(function_info->num_literals() == 0 ||
-             (code_map->get(index - 1) ==
-              cached_literals->get(JSFunction::kLiteralGlobalContextIndex)));
-      result->set_literals(cached_literals);
-    } else {
-      int number_of_literals = function_info->num_literals();
-      Handle<FixedArray> literals =
-          NewFixedArray(number_of_literals, pretenure);
-      if (number_of_literals > 0) {
-        // Store the object, regexp and array functions in the literals
-        // array prefix.  These functions will be used when creating
-        // object, regexp and array literals in this function.
-        literals->set(JSFunction::kLiteralGlobalContextIndex,
-                      context->global_context());
-      }
-      result->set_literals(*literals);
+  int index = function_info->SearchOptimizedCodeMap(context->global_context());
+  if (!function_info->bound() && index < 0) {
+    int number_of_literals = function_info->num_literals();
+    Handle<FixedArray> literals = NewFixedArray(number_of_literals, pretenure);
+    if (number_of_literals > 0) {
+      // Store the global context in the literals array prefix. This
+      // context will be used when creating object, regexp and array
+      // literals in this function.
+      literals->set(JSFunction::kLiteralGlobalContextIndex,
+                    context->global_context());
     }
+    result->set_literals(*literals);
   }
 
   if (index > 0) {
     // Caching of optimized code enabled and optimized code found.
-    Code* code = Code::cast(
-        FixedArray::cast(function_info->optimized_code_map())->get(index));
-    ASSERT(code != NULL);
-    result->ReplaceCode(code);
+    function_info->InstallFromOptimizedCodeMap(*result, index);
     return result;
   }
 

src/flag-definitions.h

@@ -209,7 +209,7 @@ DEFINE_bool(optimize_closures, true, "optimize closures")
 DEFINE_bool(lookup_sample_by_shared, true,
             "when picking a function to optimize, watch for shared function "
             "info, not JSFunction itself")
-DEFINE_bool(cache_optimized_code, false,
+DEFINE_bool(cache_optimized_code, true,
             "cache optimized code for closures")
 DEFINE_bool(inline_construct, true, "inline constructor calls")
 DEFINE_bool(inline_arguments, true, "inline functions with arguments object")

src/objects.cc

@@ -7546,6 +7546,23 @@ void SharedFunctionInfo::AddToOptimizedCodeMap(
 }
 
 
+void SharedFunctionInfo::InstallFromOptimizedCodeMap(JSFunction* function,
+                                                     int index) {
+  ASSERT(index > 0);
+  ASSERT(optimized_code_map()->IsFixedArray());
+  FixedArray* code_map = FixedArray::cast(optimized_code_map());
+  if (!bound()) {
+    FixedArray* cached_literals = FixedArray::cast(code_map->get(index + 1));
+    ASSERT(cached_literals != NULL);
+    function->set_literals(cached_literals);
+  }
+  Code* code = Code::cast(code_map->get(index));
+  ASSERT(code != NULL);
+  ASSERT(function->context()->global_context() == code_map->get(index - 1));
+  function->ReplaceCode(code);
+}
+
+
 bool JSFunction::CompileLazy(Handle<JSFunction> function,
                              ClearExceptionFlag flag) {
   bool result = true;
@@ -8097,6 +8114,7 @@ void SharedFunctionInfo::CompleteInobjectSlackTracking() {
 
 int SharedFunctionInfo::SearchOptimizedCodeMap(Context* global_context) {
   ASSERT(global_context->IsGlobalContext());
+  if (!FLAG_cache_optimized_code) return -1;
   Object* value = optimized_code_map();
   if (!value->IsSmi()) {
     FixedArray* optimized_code_map = FixedArray::cast(value);

src/objects.h

@@ -5227,6 +5227,10 @@ class SharedFunctionInfo: public HeapObject {
   // Returns -1 when no matching entry is found.
   int SearchOptimizedCodeMap(Context* global_context);
 
+  // Installs optimized code from the code map on the given closure. The
+  // index has to be consistent with a search result as defined above.
+  void InstallFromOptimizedCodeMap(JSFunction* function, int index);
+
   // Clear optimized code map.
   void ClearOptimizedCodeMap();
 

src/runtime.cc

@@ -635,6 +635,7 @@ RUNTIME_FUNCTION(MaybeObject*, Runtime_CreateArrayLiteral) {
   // Check if boilerplate exists. If not, create it first.
   Handle<Object> boilerplate(literals->get(literals_index), isolate);
   if (*boilerplate == isolate->heap()->undefined_value()) {
+    ASSERT(*elements != isolate->heap()->empty_fixed_array());
     boilerplate =
         Runtime::CreateArrayLiteralBoilerplate(isolate, literals, elements);
     if (boilerplate.is_null()) return Failure::Exception();

test/mjsunit/regress/regress-2193.js

@@ -0,0 +1,58 @@
+// Copyright 2012 the V8 project authors. All rights reserved.
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are
+// met:
+//
+//     * Redistributions of source code must retain the above copyright
+//       notice, this list of conditions and the following disclaimer.
+//     * Redistributions in binary form must reproduce the above
+//       copyright notice, this list of conditions and the following
+//       disclaimer in the documentation and/or other materials provided
+//       with the distribution.
+//     * Neither the name of Google Inc. nor the names of its
+//       contributors may be used to endorse or promote products derived
+//       from this software without specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+// Flags: --allow-natives-syntax --cache-optimized-code
+
+function bozo() {};
+function MakeClosure() {
+  return function f(use_literals) {
+    if (use_literals) {
+      return [1,2,3,3,4,5,6,7,8,9,bozo];
+    } else {
+      return 0;
+    }
+  }
+}
+
+// Create two closures that share the same literal boilerplates.
+var closure1 = MakeClosure();
+var closure2 = MakeClosure();
+var expected = [1,2,3,3,4,5,6,7,8,9,bozo];
+
+// Make sure we generate optimized code for the first closure after
+// warming it up properly so that the literals boilerplate is generated
+// and the optimized code uses CreateArrayLiteralShallow runtime call.
+assertEquals(0, closure1(false));
+assertEquals(expected, closure1(true));
+%OptimizeFunctionOnNextCall(closure1);
+assertEquals(expected, closure1(true));
+
+// Optimize the second closure, which should reuse the optimized code
+// from the first closure with the same literal boilerplates.
+assertEquals(0, closure2(false));
+%OptimizeFunctionOnNextCall(closure2);
+assertEquals(expected, closure2(true));