Enable preaging of code objects when --optimize-for-size.

test/cctest/test-heap.cc

 // 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
@@ skipping 1011 matching lines @@
     return;
   }
   CHECK(HEAP->old_pointer_space()->Contains(clone->address()));
 }
 
 
 TEST(TestCodeFlushing) {
   // If we do not flush code this test is invalid.
   if (!FLAG_flush_code) return;
   i::FLAG_allow_natives_syntax = true;
+  i::FLAG_optimize_for_size = false;
   CcTest::InitializeVM();
   Isolate* isolate = Isolate::Current();
   Factory* factory = isolate->factory();
   v8::HandleScope scope(CcTest::isolate());
   const char* source = "function foo() {"
                        "  var x = 42;"
                        "  var y = 42;"
                        "  var z = x + y;"
                        "};"
                        "foo()";
@@ skipping 25 matching lines @@
   // foo should no longer be in the compilation cache
   CHECK(!function->shared()->is_compiled() || function->IsOptimized());
   CHECK(!function->is_compiled() || function->IsOptimized());
   // Call foo to get it recompiled.
   CompileRun("foo()");
   CHECK(function->shared()->is_compiled());
   CHECK(function->is_compiled());
 }
 
 
+TEST(TestCodeFlushingPreAged) {
+  // If we do not flush code this test is invalid.
+  if (!FLAG_flush_code) return;
+  i::FLAG_allow_natives_syntax = true;
+  i::FLAG_optimize_for_size = true;
+  CcTest::InitializeVM();
+  Isolate* isolate = Isolate::Current();
+  Factory* factory = isolate->factory();
+  v8::HandleScope scope(CcTest::isolate());
+  const char* source = "function foo() {"
+                       "  var x = 42;"
+                       "  var y = 42;"
+                       "  var z = x + y;"
+                       "};"
+                       "foo()";
+  Handle<String> foo_name = factory->InternalizeUtf8String("foo");
+
+  // Compile foo, but don't run it.
+  { v8::HandleScope scope(CcTest::isolate());
+    CompileRun(source);
+  }

[rmcilroy, 2013/09/23 12:58:34]

I would like to test the immediate GCing of code that's never been executed, but
I can't figure out a way to compile, but not execute the code (removing the call
to "foo()" in source above seems to mean that foo doesn't get compiled at all). 
Any ideas?

+
+  // Check function is compiled.
+  Object* func_value = Isolate::Current()->context()->global_object()->
+      GetProperty(*foo_name)->ToObjectChecked();
+  CHECK(func_value->IsJSFunction());
+  Handle<JSFunction> function(JSFunction::cast(func_value));
+  CHECK(function->shared()->is_compiled());
+
+  // The code has been run so will survive at least one GC.
+  HEAP->CollectAllGarbage(Heap::kAbortIncrementalMarkingMask);
+  CHECK(function->shared()->is_compiled());
+
+  // The code was only run once, so it should be pre-aged and collected on the
+  // next GC.
+  HEAP->CollectAllGarbage(Heap::kAbortIncrementalMarkingMask);
+  CHECK(!function->shared()->is_compiled());
+
+  // Execute the function again twice, and ensure it is reset to the young age.
+  { v8::HandleScope scope(CcTest::isolate());
+    CompileRun("foo();"
+               "foo();");
+  }
+
+  // The code will survive at least two GC now that it is young again.
+  HEAP->CollectAllGarbage(Heap::kAbortIncrementalMarkingMask);
+  HEAP->CollectAllGarbage(Heap::kAbortIncrementalMarkingMask);
+  CHECK(function->shared()->is_compiled());
+
+  // Simulate several GCs that use full marking.
+  const int kAgingThreshold = 6;
+  for (int i = 0; i < kAgingThreshold; i++) {
+    HEAP->CollectAllGarbage(Heap::kAbortIncrementalMarkingMask);
+  }
+
+  // foo should no longer be in the compilation cache
+  CHECK(!function->shared()->is_compiled() || function->IsOptimized());
+  CHECK(!function->is_compiled() || function->IsOptimized());
+  // Call foo to get it recompiled.
+  CompileRun("foo()");
+  CHECK(function->shared()->is_compiled());
+  CHECK(function->is_compiled());
+}
+
+
 TEST(TestCodeFlushingIncremental) {
   // If we do not flush code this test is invalid.
   if (!FLAG_flush_code || !FLAG_flush_code_incrementally) return;
   i::FLAG_allow_natives_syntax = true;
+  i::FLAG_optimize_for_size = false;
   CcTest::InitializeVM();
   Isolate* isolate = Isolate::Current();
   Factory* factory = isolate->factory();
   v8::HandleScope scope(CcTest::isolate());
   const char* source = "function foo() {"
                        "  var x = 42;"
                        "  var y = 42;"
                        "  var z = x + y;"
                        "};"
                        "foo()";
@@ skipping 48 matching lines @@
   HEAP->CollectAllGarbage(Heap::kNoGCFlags);
   CHECK(function->shared()->is_compiled() || !function->IsOptimized());
   CHECK(function->is_compiled() || !function->IsOptimized());
 }
 
 
 TEST(TestCodeFlushingIncrementalScavenge) {
   // If we do not flush code this test is invalid.
   if (!FLAG_flush_code || !FLAG_flush_code_incrementally) return;
   i::FLAG_allow_natives_syntax = true;
+  i::FLAG_optimize_for_size = false;
   CcTest::InitializeVM();
   Isolate* isolate = Isolate::Current();
   Factory* factory = isolate->factory();
   v8::HandleScope scope(CcTest::isolate());
   const char* source = "var foo = function() {"
                        "  var x = 42;"
                        "  var y = 42;"
                        "  var z = x + y;"
                        "};"
                        "foo();"
@@ skipping 48 matching lines @@
   HEAP->CollectAllGarbage(Heap::kNoGCFlags);
   CHECK(!function->shared()->is_compiled() || function->IsOptimized());
   CHECK(!function->is_compiled() || function->IsOptimized());
 }
 
 
 TEST(TestCodeFlushingIncrementalAbort) {
   // If we do not flush code this test is invalid.
   if (!FLAG_flush_code || !FLAG_flush_code_incrementally) return;
   i::FLAG_allow_natives_syntax = true;
+  i::FLAG_optimize_for_size = false;
   CcTest::InitializeVM();
   Isolate* isolate = Isolate::Current();
   Factory* factory = isolate->factory();
   Heap* heap = isolate->heap();
   v8::HandleScope scope(CcTest::isolate());
   const char* source = "function foo() {"
                        "  var x = 42;"
                        "  var y = 42;"
                        "  var z = x + y;"
                        "};"
@@ skipping 2209 matching lines @@
              "    var a = new Array(n);"
              "    for (var i = 0; i < n; i += 100) a[i] = i;"
              "};"
              "f(10 * 1024 * 1024);");
   IncrementalMarking* marking = HEAP->incremental_marking();
   if (marking->IsStopped()) marking->Start();
   // This big step should be sufficient to mark the whole array.
   marking->Step(100 * MB, IncrementalMarking::NO_GC_VIA_STACK_GUARD);
   ASSERT(marking->IsComplete());
 }