cppgc: Perform caged-heap fast check when conservatively scanning

This aims to speed up stack scanning with a fast on-heap check. The
blooom-filter (at least with caged-heap enabled) is probably not needed
anymore.

Change-Id: I05536025c73df0cacdbbf6c474339dc71ecf33e5
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2825590
Commit-Queue: Anton Bikineev <bikineev@chromium.org>
Auto-Submit: Anton Bikineev <bikineev@chromium.org>
Reviewed-by: Michael Lippautz <mlippautz@chromium.org>
Reviewed-by: Omer Katz <omerkatz@chromium.org>
Cr-Commit-Position: refs/heads/main@{#76429}

src/heap/base/stack.cc

@@ -133,6 +133,7 @@ void Stack::IteratePointers(StackVisitor* visitor) const {
   PushAllRegistersAndIterateStack(this, visitor, &IteratePointersImpl);
   // No need to deal with callee-saved registers as they will be kept alive by
   // the regular conservative stack iteration.
+  // TODO(chromium:1056170): Add support for SIMD and/or filtering.
   IterateSafeStackIfNecessary(visitor);
 }
 

src/heap/cppgc/caged-heap.h

@@ -37,11 +37,21 @@ class CagedHeap final {
     return *static_cast<CagedHeapLocalData*>(reserved_area_.address());
   }
 
-  static uintptr_t OffsetFromAddress(void* address) {
+  static uintptr_t OffsetFromAddress(const void* address) {
     return reinterpret_cast<uintptr_t>(address) &
            (kCagedHeapReservationAlignment - 1);
   }
 
+  static uintptr_t BaseFromAddress(const void* address) {
+    return reinterpret_cast<uintptr_t>(address) &
+           ~(kCagedHeapReservationAlignment - 1);
+  }
+
+  bool IsOnHeap(const void* address) const {
+    return reinterpret_cast<void*>(BaseFromAddress(address)) ==
+           reserved_area_.address();
+  }
+
  private:
   VirtualMemory reserved_area_;
   std::unique_ptr<AllocatorType> bounded_allocator_;

src/heap/cppgc/visitor.cc

@@ -5,7 +5,9 @@
 #include "src/heap/cppgc/visitor.h"
 
 #include "src/base/sanitizer/msan.h"
+#include "src/heap/cppgc/caged-heap.h"
 #include "src/heap/cppgc/gc-info-table.h"
+#include "src/heap/cppgc/heap-base.h"
 #include "src/heap/cppgc/heap-object-header.h"
 #include "src/heap/cppgc/heap-page.h"
 #include "src/heap/cppgc/object-view.h"
@@ -50,6 +52,11 @@ void TraceConservatively(ConservativeTracingVisitor* conservative_visitor,
 
 void ConservativeTracingVisitor::TraceConservativelyIfNeeded(
     const void* address) {
+#if defined(CPPGC_CAGED_HEAP)
+  // TODO(chromium:1056170): Add support for SIMD in stack scanning.
+  if (V8_LIKELY(!heap_.caged_heap().IsOnHeap(address))) return;
+#endif
+
   const BasePage* page = reinterpret_cast<const BasePage*>(
       page_backend_.Lookup(static_cast<ConstAddress>(address)));