deps: V8: cherry-pick 392316d

Original commit message:

    [ptr-compr][x64] Define kTaggedSize as kInt32Size

    ... when pointer compression is enabled and some number of cleanups.

    Bug: v8:7703
    Change-Id: If7344abf68a1c4d54e4a79d066dc185f25055d7d
    Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/1477737
    Commit-Queue: Igor Sheludko <ishell@chromium.org>
    Auto-Submit: Igor Sheludko <ishell@chromium.org>
    Reviewed-by: Ulan Degenbaev <ulan@chromium.org>
    Reviewed-by: Toon Verwaest <verwaest@chromium.org>
    Cr-Commit-Position: refs/heads/master@{#60056}

Refs: https://github.com/v8/v8/commit/392316ddd11104ad759131732dfe0805f3972ab2

PR-URL: https://github.com/nodejs/node/pull/26685
Reviewed-By: Anna Henningsen <anna@addaleax.net>
Reviewed-By: Michaël Zasso <targos@protonmail.com>
Reviewed-By: Refael Ackermann <refack@gmail.com>

2 files changed, 43 insertions, 41 deletions

diff --git a/deps/v8/include/v8-internal.h b/deps/v8/include/v8-internal.h
index bb69bb915d..5cc62f3e72 100644
--- a/deps/v8/include/v8-internal.h
+++ b/deps/v8/include/v8-internal.h
@@ -29,7 +29,6 @@ static const Address kNullAddress = 0;
  * Configuration of tagging scheme.
  */
 const int kApiSystemPointerSize = sizeof(void*);
-const int kApiTaggedSize = kApiSystemPointerSize;
 const int kApiDoubleSize = sizeof(double);
 const int kApiInt32Size = sizeof(int32_t);
 const int kApiInt64Size = sizeof(int64_t);
@@ -92,6 +91,9 @@ struct SmiTagging<8> {
 static_assert(
     kApiSystemPointerSize == kApiInt64Size,
     "Pointer compression can be enabled only for 64-bit architectures");
+const int kApiTaggedSize = kApiInt32Size;
+#else
+const int kApiTaggedSize = kApiSystemPointerSize;
 #endif
 
 #ifdef V8_31BIT_SMIS_ON_64BIT_ARCH
@@ -131,11 +133,7 @@ class Internals {
   static const int kJSObjectHeaderSize = 3 * kApiTaggedSize;
   static const int kFixedArrayHeaderSize = 2 * kApiTaggedSize;
   static const int kEmbedderDataArrayHeaderSize = 2 * kApiTaggedSize;
-  static const int kEmbedderDataSlotSize =
-#ifdef V8_COMPRESS_POINTERS
-      2 *
-#endif
-      kApiSystemPointerSize;
+  static const int kEmbedderDataSlotSize = kApiSystemPointerSize;
   static const int kNativeContextEmbedderDataOffset = 7 * kApiTaggedSize;
   static const int kFullStringRepresentationMask = 0x0f;
   static const int kStringEncodingMask = 0x8;
@@ -301,22 +299,8 @@ class Internals {
 #endif
   }
 
-  V8_INLINE static internal::Address ReadTaggedAnyField(
-      internal::Address heap_object_ptr, int offset) {
-#ifdef V8_COMPRESS_POINTERS
-    int32_t value = ReadRawField<int32_t>(heap_object_ptr, offset);
-    internal::Address root_mask = static_cast<internal::Address>(
-        -static_cast<intptr_t>(value & kSmiTagMask));
-    internal::Address root_or_zero =
-        root_mask & GetRootFromOnHeapAddress(heap_object_ptr);
-    return root_or_zero +
-           static_cast<internal::Address>(static_cast<intptr_t>(value));
-#else
-    return ReadRawField<internal::Address>(heap_object_ptr, offset);
-#endif
-  }
-
 #ifdef V8_COMPRESS_POINTERS
+  // See v8:7703 or src/ptr-compr.* for details about pointer compression.
   static constexpr size_t kPtrComprHeapReservationSize = size_t{1} << 32;
   static constexpr size_t kPtrComprIsolateRootBias =
       kPtrComprHeapReservationSize / 2;
@@ -328,18 +312,14 @@ class Internals {
            -static_cast<intptr_t>(kPtrComprIsolateRootAlignment);
   }
 
-#else
-
-  template <typename T>
-  V8_INLINE static T ReadEmbedderData(const v8::Context* context, int index) {
-    typedef internal::Address A;
-    typedef internal::Internals I;
-    A ctx = *reinterpret_cast<const A*>(context);
-    A embedder_data =
-        I::ReadTaggedPointerField(ctx, I::kNativeContextEmbedderDataOffset);
-    int value_offset =
-        I::kEmbedderDataArrayHeaderSize + (I::kEmbedderDataSlotSize * index);
-    return I::ReadRawField<T>(embedder_data, value_offset);
+  V8_INLINE static internal::Address DecompressTaggedAnyField(
+      internal::Address heap_object_ptr, int32_t value) {
+    internal::Address root_mask = static_cast<internal::Address>(
+        -static_cast<intptr_t>(value & kSmiTagMask));
+    internal::Address root_or_zero =
+        root_mask & GetRootFromOnHeapAddress(heap_object_ptr);
+    return root_or_zero +
+           static_cast<internal::Address>(static_cast<intptr_t>(value));
   }
 #endif  // V8_COMPRESS_POINTERS
 };
diff --git a/deps/v8/include/v8.h b/deps/v8/include/v8.h
index 987748ca00..5e45cc7620 100644
--- a/deps/v8/include/v8.h
+++ b/deps/v8/include/v8.h
@@ -10322,7 +10322,7 @@ AccessorSignature* AccessorSignature::Cast(Data* data) {
 }
 
 Local<Value> Object::GetInternalField(int index) {
-#if !defined(V8_ENABLE_CHECKS) && !defined(V8_COMPRESS_POINTERS)
+#ifndef V8_ENABLE_CHECKS
   typedef internal::Address A;
   typedef internal::Internals I;
   A obj = *reinterpret_cast<A*>(this);
@@ -10333,7 +10333,12 @@ Local<Value> Object::GetInternalField(int index) {
       instance_type == I::kJSApiObjectType ||
       instance_type == I::kJSSpecialApiObjectType) {
     int offset = I::kJSObjectHeaderSize + (I::kEmbedderDataSlotSize * index);
-    A value = I::ReadTaggedAnyField(obj, offset);
+    A value = I::ReadRawField<A>(obj, offset);
+#ifdef V8_COMPRESS_POINTERS
+    // We read the full pointer value and then decompress it in order to avoid
+    // dealing with potential endiannes issues.
+    value = I::DecompressTaggedAnyField(obj, static_cast<int32_t>(value));
+#endif
     internal::Isolate* isolate =
         internal::IsolateFromNeverReadOnlySpaceObject(obj);
     A* result = HandleScope::CreateHandle(isolate, value);
@@ -10345,7 +10350,7 @@ Local<Value> Object::GetInternalField(int index) {
 
 
 void* Object::GetAlignedPointerFromInternalField(int index) {
-#if !defined(V8_ENABLE_CHECKS) && !defined(V8_COMPRESS_POINTERS)
+#ifndef V8_ENABLE_CHECKS
   typedef internal::Address A;
   typedef internal::Internals I;
   A obj = *reinterpret_cast<A*>(this);
@@ -10956,13 +10961,24 @@ int64_t Isolate::AdjustAmountOfExternalAllocatedMemory(
 }
 
 Local<Value> Context::GetEmbedderData(int index) {
-#if !defined(V8_ENABLE_CHECKS) && !defined(V8_COMPRESS_POINTERS)
+#ifndef V8_ENABLE_CHECKS
   typedef internal::Address A;
   typedef internal::Internals I;
+  A ctx = *reinterpret_cast<const A*>(this);
+  A embedder_data =
+      I::ReadTaggedPointerField(ctx, I::kNativeContextEmbedderDataOffset);
+  int value_offset =
+      I::kEmbedderDataArrayHeaderSize + (I::kEmbedderDataSlotSize * index);
+  A value = I::ReadRawField<A>(embedder_data, value_offset);
+#ifdef V8_COMPRESS_POINTERS
+  // We read the full pointer value and then decompress it in order to avoid
+  // dealing with potential endiannes issues.
+  value =
+      I::DecompressTaggedAnyField(embedder_data, static_cast<int32_t>(value));
+#endif
   internal::Isolate* isolate = internal::IsolateFromNeverReadOnlySpaceObject(
       *reinterpret_cast<A*>(this));
-  A* result =
-      HandleScope::CreateHandle(isolate, I::ReadEmbedderData<A>(this, index));
+  A* result = HandleScope::CreateHandle(isolate, value);
   return Local<Value>(reinterpret_cast<Value*>(result));
 #else
   return SlowGetEmbedderData(index);
@@ -10971,9 +10987,15 @@ Local<Value> Context::GetEmbedderData(int index) {
 
 
 void* Context::GetAlignedPointerFromEmbedderData(int index) {
-#if !defined(V8_ENABLE_CHECKS) && !defined(V8_COMPRESS_POINTERS)
+#ifndef V8_ENABLE_CHECKS
+  typedef internal::Address A;
   typedef internal::Internals I;
-  return I::ReadEmbedderData<void*>(this, index);
+  A ctx = *reinterpret_cast<const A*>(this);
+  A embedder_data =
+      I::ReadTaggedPointerField(ctx, I::kNativeContextEmbedderDataOffset);
+  int value_offset =
+      I::kEmbedderDataArrayHeaderSize + (I::kEmbedderDataSlotSize * index);
+  return I::ReadRawField<void*>(embedder_data, value_offset);
 #else
   return SlowGetAlignedPointerFromEmbedderData(index);
 #endif