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: v8/v8@392316d

PR-URL: #26685
Reviewed-By: Anna Henningsen <anna@addaleax.net>
Reviewed-By: Michaël Zasso <targos@protonmail.com>
Reviewed-By: Refael Ackermann <refack@gmail.com>

Author: addaleax

common.gypi

@@ -37,7 +37,7 @@
 
     # Reset this number to 0 on major V8 upgrades.
     # Increment by one for each non-official patch applied to deps/v8.
-    'v8_embedder_string': '-node.1',
+    'v8_embedder_string': '-node.2',
 
     ##### V8 defaults for Node.js #####
 

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
 };

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

deps/v8/src/globals.h

@@ -200,28 +200,47 @@ constexpr size_t kReservedCodeRangePages = 0;
 
 STATIC_ASSERT(kSystemPointerSize == (1 << kSystemPointerSizeLog2));
 
+#ifdef V8_COMPRESS_POINTERS
+static_assert(
+    kSystemPointerSize == kInt64Size,
+    "Pointer compression can be enabled only for 64-bit architectures");
+
+constexpr int kTaggedSize = kInt32Size;
+constexpr int kTaggedSizeLog2 = 2;
+
+// These types define raw and atomic storage types for tagged values stored
+// on V8 heap.
+using Tagged_t = int32_t;
+using AtomicTagged_t = base::Atomic32;
+
+#else
+
 constexpr int kTaggedSize = kSystemPointerSize;
 constexpr int kTaggedSizeLog2 = kSystemPointerSizeLog2;
-STATIC_ASSERT(kTaggedSize == (1 << kTaggedSizeLog2));
 
 // These types define raw and atomic storage types for tagged values stored
 // on V8 heap.
 using Tagged_t = Address;
 using AtomicTagged_t = base::AtomicWord;
+
+#endif  // V8_COMPRESS_POINTERS
+
+STATIC_ASSERT(kTaggedSize == (1 << kTaggedSizeLog2));
+
 using AsAtomicTagged = base::AsAtomicPointerImpl<AtomicTagged_t>;
 STATIC_ASSERT(sizeof(Tagged_t) == kTaggedSize);
 STATIC_ASSERT(sizeof(AtomicTagged_t) == kTaggedSize);
 
+STATIC_ASSERT(kTaggedSize == kApiTaggedSize);
+
 // TODO(ishell): use kTaggedSize or kSystemPointerSize instead.
+#ifndef V8_COMPRESS_POINTERS
 constexpr int kPointerSize = kSystemPointerSize;
 constexpr int kPointerSizeLog2 = kSystemPointerSizeLog2;
 STATIC_ASSERT(kPointerSize == (1 << kPointerSizeLog2));
-
-constexpr int kEmbedderDataSlotSize =
-#ifdef V8_COMPRESS_POINTERS
-    kTaggedSize +
 #endif
-    kTaggedSize;
+
+constexpr int kEmbedderDataSlotSize = kSystemPointerSize;
 
 constexpr int kEmbedderDataSlotSizeInTaggedSlots =
     kEmbedderDataSlotSize / kTaggedSize;
@@ -870,33 +889,32 @@ constexpr int kIeeeDoubleExponentWordOffset = 0;
     ::i::kHeapObjectTag))
 
 // OBJECT_POINTER_ALIGN returns the value aligned as a HeapObject pointer
-#define OBJECT_POINTER_ALIGN(value)                             \
-  (((value) + kObjectAlignmentMask) & ~kObjectAlignmentMask)
+#define OBJECT_POINTER_ALIGN(value) \
+  (((value) + ::i::kObjectAlignmentMask) & ~::i::kObjectAlignmentMask)
 
 // OBJECT_POINTER_PADDING returns the padding size required to align value
 // as a HeapObject pointer
 #define OBJECT_POINTER_PADDING(value) (OBJECT_POINTER_ALIGN(value) - (value))
 
 // POINTER_SIZE_ALIGN returns the value aligned as a system pointer.
-#define POINTER_SIZE_ALIGN(value)                               \
-  (((value) + kPointerAlignmentMask) & ~kPointerAlignmentMask)
+#define POINTER_SIZE_ALIGN(value) \
+  (((value) + ::i::kPointerAlignmentMask) & ~::i::kPointerAlignmentMask)
 
 // POINTER_SIZE_PADDING returns the padding size required to align value
 // as a system pointer.
 #define POINTER_SIZE_PADDING(value) (POINTER_SIZE_ALIGN(value) - (value))
 
 // CODE_POINTER_ALIGN returns the value aligned as a generated code segment.
-#define CODE_POINTER_ALIGN(value)                               \
-  (((value) + kCodeAlignmentMask) & ~kCodeAlignmentMask)
+#define CODE_POINTER_ALIGN(value) \
+  (((value) + ::i::kCodeAlignmentMask) & ~::i::kCodeAlignmentMask)
 
 // CODE_POINTER_PADDING returns the padding size required to align value
 // as a generated code segment.
 #define CODE_POINTER_PADDING(value) (CODE_POINTER_ALIGN(value) - (value))
 
 // DOUBLE_POINTER_ALIGN returns the value algined for double pointers.
 #define DOUBLE_POINTER_ALIGN(value) \
-  (((value) + kDoubleAlignmentMask) & ~kDoubleAlignmentMask)
-
+  (((value) + ::i::kDoubleAlignmentMask) & ~::i::kDoubleAlignmentMask)
 
 // Defines hints about receiver values based on structural knowledge.
 enum class ConvertReceiverMode : unsigned {

deps/v8/src/memcopy.h

@@ -138,6 +138,32 @@ inline void CopyBytes(T* dst, const T* src, size_t num_bytes) {
   CopyImpl<kMinComplexMemCopy>(dst, src, num_bytes);
 }
 
+inline void MemsetInt32(int32_t* dest, int32_t value, size_t counter) {
+#if V8_HOST_ARCH_IA32 || V8_HOST_ARCH_X64
+#define STOS "stosl"
+#endif
+
+#if defined(MEMORY_SANITIZER)
+  // MemorySanitizer does not understand inline assembly.
+#undef STOS
+#endif
+
+#if defined(__GNUC__) && defined(STOS)
+  asm volatile(
+      "cld;"
+      "rep ; " STOS
+      : "+&c"(counter), "+&D"(dest)
+      : "a"(value)
+      : "memory", "cc");
+#else
+  for (size_t i = 0; i < counter; i++) {
+    dest[i] = value;
+  }
+#endif
+
+#undef STOS
+}
+
 inline void MemsetPointer(Address* dest, Address value, size_t counter) {
 #if V8_HOST_ARCH_IA32
 #define STOS "stosl"

deps/v8/src/objects-inl.h

@@ -614,33 +614,18 @@ HeapObject MapWord::ToForwardingAddress() {
 #ifdef VERIFY_HEAP
 void HeapObject::VerifyObjectField(Isolate* isolate, int offset) {
   VerifyPointer(isolate, READ_FIELD(*this, offset));
-#ifdef V8_COMPRESS_POINTERS
-  STATIC_ASSERT(kTaggedSize == kSystemPointerSize);
-  // Ensure upper 32-bits are zeros.
-  Address value = *(FullObjectSlot(FIELD_ADDR(*this, offset)).location());
-  CHECK_EQ(kNullAddress, RoundDown<kPtrComprIsolateRootAlignment>(value));
-#endif
+  STATIC_ASSERT(!COMPRESS_POINTERS_BOOL || kTaggedSize == kInt32Size);
 }
 
 void HeapObject::VerifyMaybeObjectField(Isolate* isolate, int offset) {
   MaybeObject::VerifyMaybeObjectPointer(isolate,
                                         READ_WEAK_FIELD(*this, offset));
-#ifdef V8_COMPRESS_POINTERS
-  STATIC_ASSERT(kTaggedSize == kSystemPointerSize);
-  // Ensure upper 32-bits are zeros.
-  Address value = *(FullObjectSlot(FIELD_ADDR(*this, offset)).location());
-  CHECK_EQ(kNullAddress, RoundDown<kPtrComprIsolateRootAlignment>(value));
-#endif
+  STATIC_ASSERT(!COMPRESS_POINTERS_BOOL || kTaggedSize == kInt32Size);
 }
 
 void HeapObject::VerifySmiField(int offset) {
   CHECK(READ_FIELD(*this, offset)->IsSmi());
-#ifdef V8_COMPRESS_POINTERS
-  STATIC_ASSERT(kTaggedSize == kSystemPointerSize);
-  // Ensure upper 32-bits are zeros.
-  Address value = *(FullObjectSlot(FIELD_ADDR(*this, offset)).location());
-  CHECK_EQ(kNullAddress, RoundDown<kPtrComprIsolateRootAlignment>(value));
-#endif
+  STATIC_ASSERT(!COMPRESS_POINTERS_BOOL || kTaggedSize == kInt32Size);
 }
 
 #endif

deps/v8/src/objects/code.h

@@ -402,11 +402,11 @@ class Code : public HeapObject {
   // This documents the amount of free space we have in each Code object header
   // due to padding for code alignment.
 #if V8_TARGET_ARCH_ARM64
-  static constexpr int kHeaderPaddingSize = 0;
+  static constexpr int kHeaderPaddingSize = COMPRESS_POINTERS_BOOL ? 20 : 0;
 #elif V8_TARGET_ARCH_MIPS64
   static constexpr int kHeaderPaddingSize = 0;
 #elif V8_TARGET_ARCH_X64
-  static constexpr int kHeaderPaddingSize = 0;
+  static constexpr int kHeaderPaddingSize = COMPRESS_POINTERS_BOOL ? 20 : 0;
 #elif V8_TARGET_ARCH_ARM
   static constexpr int kHeaderPaddingSize = 20;
 #elif V8_TARGET_ARCH_IA32