src/v8/src/allocation-site-scopes.cc

   1 // Copyright 2013 the V8 project authors. All rights reserved.
   2 // Use of this source code is governed by a BSD-style license that can be
   3 // found in the LICENSE file.
   4
   5 #include "src/allocation-site-scopes.h"
   6
   7 namespace v8 {
   8 namespace internal {
   9
  10
  11 Handle<AllocationSite> AllocationSiteCreationContext::EnterNewScope() {
  12   Handle<AllocationSite> scope_site;
  13   if (top().is_null()) {
  14     // We are creating the top level AllocationSite as opposed to a nested
  15     // AllocationSite.
  16     InitializeTraversal(isolate()->factory()->NewAllocationSite());
  17     scope_site = Handle<AllocationSite>(*top(), isolate());
  18     if (FLAG_trace_creation_allocation_sites) {
  19       PrintF("*** Creating top level AllocationSite %p\n",
  20              static_cast<void*>(*scope_site));
  21     }
  22   } else {
  23     DCHECK(!current().is_null());
  24     scope_site = isolate()->factory()->NewAllocationSite();
  25     if (FLAG_trace_creation_allocation_sites) {
  26       PrintF("Creating nested site (top, current, new) (%p, %p, %p)\n",
  27              static_cast<void*>(*top()),
  28              static_cast<void*>(*current()),
  29              static_cast<void*>(*scope_site));
  30     }
  31     current()->set_nested_site(*scope_site);
  32     update_current_site(*scope_site);
  33   }
  34   DCHECK(!scope_site.is_null());
  35   return scope_site;
  36 }
  37
  38
  39 void AllocationSiteCreationContext::ExitScope(
  40     Handle<AllocationSite> scope_site,
  41     Handle<JSObject> object) {
  42   if (!object.is_null()) {
  43     bool top_level = !scope_site.is_null() &&
  44         top().is_identical_to(scope_site);
  45
  46     scope_site->set_transition_info(*object);
  47     if (FLAG_trace_creation_allocation_sites) {
  48       if (top_level) {
  49         PrintF("*** Setting AllocationSite %p transition_info %p\n",
  50                static_cast<void*>(*scope_site),
  51                static_cast<void*>(*object));
  52       } else {
  53         PrintF("Setting AllocationSite (%p, %p) transition_info %p\n",
  54                static_cast<void*>(*top()),
  55                static_cast<void*>(*scope_site),
  56                static_cast<void*>(*object));
  57       }
  58     }
  59   }
  60 }
  61
  62
  63 bool AllocationSiteUsageContext::ShouldCreateMemento(Handle<JSObject> object) {
  64   if (activated_ && AllocationSite::CanTrack(object->map()->instance_type())) {
  65     if (FLAG_allocation_site_pretenuring ||
  66         AllocationSite::GetMode(object->GetElementsKind()) ==
  67         TRACK_ALLOCATION_SITE) {
  68       if (FLAG_trace_creation_allocation_sites) {
  69         PrintF("*** Creating Memento for %s %p\n",
  70                object->IsJSArray() ? "JSArray" : "JSObject",
  71                static_cast<void*>(*object));
  72       }
  73       return true;
  74     }
  75   }
  76   return false;
  77 }
  78
  79 } }  // namespace v8::internal