[test] Make full space simulation work with --no-inline-new.

When inlined allocations are disabled, the space->limit() does not point to the
end of the current page. Instead, it points to the current allocation pointer so
is the same as space->top().

See how the limit is computed, if heap()->inline_allocation_disabled(), then the
limit will be the same as the requested allocation area:

```
Address SpaceWithLinearArea::ComputeLimit(Address start, Address end,
                                          size_t min_size) {
  DCHECK_GE(end - start, min_size);

  if (heap()->inline_allocation_disabled()) {
    // Fit the requested area exactly.
    return start + min_size;
  } else if (SupportsInlineAllocation() && AllocationObserversActive()) {
    // ...
  } else {
    // The entire node can be used as the linear allocation area.
    return end;
  }
}
```

If we want to simulate filling up a whole page in the new space, we can instead
look at the ToSpace's page_high() which will be the end of the current page in
which we're allocating.

Bug: v8:9906
Change-Id: I81113d151bc083cd22d17ea1a4fbae7fef9dff6d
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/1886914Reviewed-by: Ulan Degenbaev <ulan@chromium.org>
Commit-Queue: Pierre Langlois <pierre.langlois@arm.com>
Cr-Commit-Position: refs/heads/master@{#64612}

src/runtime/runtime-test.cc

@@ -684,9 +684,15 @@ int FixedArrayLenFromSize(int size) {
 }
 
 void FillUpOneNewSpacePage(Isolate* isolate, Heap* heap) {
+  PauseAllocationObserversScope pause_observers(heap);
   NewSpace* space = heap->new_space();
-  int space_remaining = static_cast<int>(*space->allocation_limit_address() -
-                                         *space->allocation_top_address());
+  // We cannot rely on `space->limit()` to point to the end of the current page
+  // in the case where inline allocations are disabled, it actually points to
+  // the current allocation pointer.
+  DCHECK_IMPLIES(space->heap()->inline_allocation_disabled(),
+                 space->limit() == space->top());
+  int space_remaining =
+      static_cast<int>(space->to_space().page_high() - space->top());
   while (space_remaining > 0) {
     int length = FixedArrayLenFromSize(space_remaining);
     if (length > 0) {
@@ -709,7 +715,6 @@ RUNTIME_FUNCTION(Runtime_SimulateNewspaceFull) {
   HandleScope scope(isolate);
   Heap* heap = isolate->heap();
   NewSpace* space = heap->new_space();
-  PauseAllocationObserversScope pause_observers(heap);
   AlwaysAllocateScope always_allocate(heap);
   do {
     FillUpOneNewSpacePage(isolate, heap);

test/cctest/heap/heap-utils.cc

@@ -121,32 +121,24 @@ std::vector<Handle<FixedArray>> CreatePadding(Heap* heap, int padding_size,
   return handles;
 }
 
-void AllocateAllButNBytes(v8::internal::NewSpace* space, int extra_bytes,
+bool FillCurrentPage(v8::internal::NewSpace* space,
                      std::vector<Handle<FixedArray>>* out_handles) {
-  PauseAllocationObserversScope pause_observers(space->heap());
-  int space_remaining = static_cast<int>(*space->allocation_limit_address() -
-                                         *space->allocation_top_address());
-  CHECK(space_remaining >= extra_bytes);
-  int new_linear_size = space_remaining - extra_bytes;
-  if (new_linear_size == 0) return;
-  std::vector<Handle<FixedArray>> handles = heap::CreatePadding(
-      space->heap(), new_linear_size, i::AllocationType::kYoung);
-  if (out_handles != nullptr) {
-    out_handles->insert(out_handles->end(), handles.begin(), handles.end());
-  }
-}
-
-void FillCurrentPage(v8::internal::NewSpace* space,
-                     std::vector<Handle<FixedArray>>* out_handles) {
-  heap::AllocateAllButNBytes(space, 0, out_handles);
+  return heap::FillCurrentPageButNBytes(space, 0, out_handles);
 }
 
-bool FillUpOnePage(v8::internal::NewSpace* space,
+bool FillCurrentPageButNBytes(v8::internal::NewSpace* space, int extra_bytes,
                               std::vector<Handle<FixedArray>>* out_handles) {
   PauseAllocationObserversScope pause_observers(space->heap());
-  int space_remaining = static_cast<int>(*space->allocation_limit_address() -
-                                         *space->allocation_top_address());
-  if (space_remaining == 0) return false;
+  // We cannot rely on `space->limit()` to point to the end of the current page
+  // in the case where inline allocations are disabled, it actually points to
+  // the current allocation pointer.
+  DCHECK_IMPLIES(space->heap()->inline_allocation_disabled(),
+                 space->limit() == space->top());
+  int space_remaining =
+      static_cast<int>(space->to_space().page_high() - space->top());
+  CHECK(space_remaining >= extra_bytes);
+  int new_linear_size = space_remaining - extra_bytes;
+  if (new_linear_size == 0) return false;
   std::vector<Handle<FixedArray>> handles = heap::CreatePadding(
       space->heap(), space_remaining, i::AllocationType::kYoung);
   if (out_handles != nullptr) {
@@ -157,8 +149,7 @@ bool FillUpOnePage(v8::internal::NewSpace* space,
 
 void SimulateFullSpace(v8::internal::NewSpace* space,
                        std::vector<Handle<FixedArray>>* out_handles) {
-  heap::FillCurrentPage(space, out_handles);
-  while (heap::FillUpOnePage(space, out_handles) || space->AddFreshPage()) {
+  while (heap::FillCurrentPage(space, out_handles) || space->AddFreshPage()) {
   }
 }
 

test/cctest/heap/heap-utils.h

@@ -42,17 +42,14 @@ std::vector<Handle<FixedArray>> CreatePadding(
     Heap* heap, int padding_size, AllocationType allocation,
     int object_size = kMaxRegularHeapObjectSize);
 
-void AllocateAllButNBytes(
-    v8::internal::NewSpace* space, int extra_bytes,
+bool FillCurrentPage(v8::internal::NewSpace* space,
                      std::vector<Handle<FixedArray>>* out_handles = nullptr);
 
-void FillCurrentPage(v8::internal::NewSpace* space,
+bool FillCurrentPageButNBytes(
+    v8::internal::NewSpace* space, int extra_bytes,
     std::vector<Handle<FixedArray>>* out_handles = nullptr);
 
 // Helper function that simulates a full new-space in the heap.
-bool FillUpOnePage(v8::internal::NewSpace* space,
-                   std::vector<Handle<FixedArray>>* out_handles = nullptr);
-
 void SimulateFullSpace(v8::internal::NewSpace* space,
                        std::vector<Handle<FixedArray>>* out_handles = nullptr);
 

test/cctest/heap/test-heap.cc

@@ -3558,7 +3558,7 @@ TEST(Regress169928) {
   array_data->set(0, Smi::FromInt(1));
   array_data->set(1, Smi::FromInt(2));
 
-  heap::AllocateAllButNBytes(
+  heap::FillCurrentPageButNBytes(
       CcTest::heap()->new_space(),
       JSArray::kSize + AllocationMemento::kSize + kTaggedSize);