[build] Change Typed Array threshold to an actual build time flag.

This was supposedly a runtime flag, but we baked it into the snapshot
anyway.

Change-Id: I09d43183c4c2d59336c1077089119d6cb65dfd87
Reviewed-on: https://chromium-review.googlesource.com/664721
Reviewed-by: Yang Guo <yangguo@chromium.org>
Reviewed-by: Michael Starzinger <mstarzinger@chromium.org>
Reviewed-by: Michael Achenbach <machenbach@chromium.org>
Commit-Queue: Peter Marshall <petermarshall@chromium.org>
Cr-Commit-Position: refs/heads/master@{#48026}

BUILD.gn

@@ -107,6 +107,9 @@ declare_args() {
   # Similar to the ARM hard float ABI but on MIPS.
   v8_use_mips_abi_hardfloat = true
 
+  # Controls the threshold for on-heap/off-heap Typed Arrays.
+  v8_typed_array_max_size_in_heap = 64
+
   # List of extra files to snapshot. They will be snapshotted in order so
   # if files export symbols used by later files, they should go first.
   #
@@ -235,6 +238,8 @@ config("features") {
     defines +=
         [ "V8_PROMISE_INTERNAL_FIELD_COUNT=${v8_promise_internal_field_count}" ]
   }
+  defines +=
+      [ "V8_TYPED_ARRAY_MAX_SIZE_IN_HEAP=${v8_typed_array_max_size_in_heap}" ]
   if (v8_enable_future) {
     defines += [ "V8_ENABLE_FUTURE" ]
   }

gypfiles/features.gypi

@@ -83,6 +83,9 @@
 
     # Enable concurrent marking.
     'v8_enable_concurrent_marking%': 0,
+
+    # Controls the threshold for on-heap/off-heap Typed Arrays.
+    'v8_typed_array_max_size_in_heap%': 64,
   },
   'target_defaults': {
     'conditions': [
@@ -160,6 +163,7 @@
     },  # configurations
     'defines': [
       'V8_GYP_BUILD',
+      'V8_TYPED_ARRAY_MAX_SIZE_IN_HEAP=<(v8_typed_array_max_size_in_heap)',
     ],  # defines
   },  # target_defaults
 }

src/builtins/builtins-typedarray-gen.cc

@@ -10,6 +10,12 @@
 namespace v8 {
 namespace internal {
 
+// This is needed for gc_mole which will compile this file without the full set
+// of GN defined macros.
+#ifndef V8_TYPED_ARRAY_MAX_SIZE_IN_HEAP
+#define V8_TYPED_ARRAY_MAX_SIZE_IN_HEAP 64
+#endif
+
 // -----------------------------------------------------------------------------
 // ES6 section 22.2 TypedArray Objects
 
@@ -200,8 +206,8 @@ TF_BUILTIN(TypedArrayInitialize, TypedArrayBuiltinsAssembler) {
 
   Node* fixed_typed_map = LoadMapForType(holder);
   GotoIf(TaggedIsNotSmi(byte_length), &allocate_off_heap);
-  GotoIf(SmiGreaterThan(byte_length,
-                        SmiConstant(FLAG_typed_array_max_size_in_heap)),
+  GotoIf(
+      SmiGreaterThan(byte_length, SmiConstant(V8_TYPED_ARRAY_MAX_SIZE_IN_HEAP)),
       &allocate_off_heap);
   Goto(&allocate_on_heap);
 
@@ -734,5 +740,7 @@ TF_BUILTIN(TypedArrayPrototypeKeys, TypedArrayBuiltinsAssembler) {
       context, receiver, "%TypedArray%.prototype.keys()", IterationKind::kKeys);
 }
 
+#undef V8_TYPED_ARRAY_MAX_SIZE_IN_HEAP
+
 }  // namespace internal
 }  // namespace v8

src/compiler/js-intrinsic-lowering.cc

@@ -98,8 +98,6 @@ Reduction JSIntrinsicLowering::Reduce(Node* node) {
     case Runtime::kInlineTypedArrayGetLength:
       return ReduceArrayBufferViewField(node,
                                         AccessBuilder::ForJSTypedArrayLength());
-    case Runtime::kInlineTypedArrayMaxSizeInHeap:
-      return ReduceTypedArrayMaxSizeInHeap(node);
     case Runtime::kInlineTheHole:
       return ReduceTheHole(node);
     case Runtime::kInlineClassOf:
@@ -383,12 +381,6 @@ Reduction JSIntrinsicLowering::ReduceMaxSmi(Node* node) {
   return Replace(value);
 }
 
-Reduction JSIntrinsicLowering::ReduceTypedArrayMaxSizeInHeap(Node* node) {
-  Node* value = jsgraph()->Constant(FLAG_typed_array_max_size_in_heap);
-  ReplaceWithValue(node, value);
-  return Replace(value);
-}
-
 Reduction JSIntrinsicLowering::ReduceTheHole(Node* node) {
   Node* value = jsgraph()->TheHoleConstant();
   ReplaceWithValue(node, value);

src/compiler/js-intrinsic-lowering.h

@@ -68,7 +68,6 @@ class V8_EXPORT_PRIVATE JSIntrinsicLowering final
   Reduction ReduceArrayBufferViewField(Node* node, FieldAccess const& access);
   Reduction ReduceArrayBufferViewWasNeutered(Node* node);
   Reduction ReduceMaxSmi(Node* node);
-  Reduction ReduceTypedArrayMaxSizeInHeap(Node* node);
 
   // TODO(turbofan): collection.js support; drop once Maps and Sets are
   // converted to proper CodeStubAssembler based builtins.

src/runtime/runtime-typedarray.cc

@@ -156,14 +156,6 @@ RUNTIME_FUNCTION(Runtime_TypedArraySortFast) {
   return *array;
 }
 
-RUNTIME_FUNCTION(Runtime_TypedArrayMaxSizeInHeap) {
-  DCHECK_EQ(0, args.length());
-  DCHECK_OBJECT_SIZE(FLAG_typed_array_max_size_in_heap +
-                     FixedTypedArrayBase::kDataOffset);
-  return Smi::FromInt(FLAG_typed_array_max_size_in_heap);
-}
-
-
 RUNTIME_FUNCTION(Runtime_IsTypedArray) {
   HandleScope scope(isolate);
   DCHECK_EQ(1, args.length());

src/runtime/runtime.h

@@ -630,7 +630,6 @@ namespace internal {
   F(TypedArrayGetLength, 1, 1)           \
   F(TypedArrayGetBuffer, 1, 1)           \
   F(TypedArraySortFast, 1, 1)            \
-  F(TypedArrayMaxSizeInHeap, 0, 1)       \
   F(IsTypedArray, 1, 1)                  \
   F(IsSharedTypedArray, 1, 1)            \
   F(IsSharedIntegerTypedArray, 1, 1)     \