// Copyright 2012 the V8 project authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
#ifndef V8_GLOBALS_H_
#define V8_GLOBALS_H_
#include <stddef.h>
#include <stdint.h>
#include <ostream>
#include "src/base/build_config.h"
#include "src/base/logging.h"
#include "src/base/macros.h"
#ifdef V8_OS_WIN
// Setup for Windows shared library export.
#ifdef BUILDING_V8_SHARED
#define V8_EXPORT_PRIVATE __declspec(dllexport)
#elif USING_V8_SHARED
#define V8_EXPORT_PRIVATE __declspec(dllimport)
#else
#define V8_EXPORT_PRIVATE
#endif // BUILDING_V8_SHARED
#else // V8_OS_WIN
// Setup for Linux shared library export.
#if V8_HAS_ATTRIBUTE_VISIBILITY
#ifdef BUILDING_V8_SHARED
#define V8_EXPORT_PRIVATE __attribute__((visibility("default")))
#else
#define V8_EXPORT_PRIVATE
#endif
#else
#define V8_EXPORT_PRIVATE
#endif
#endif // V8_OS_WIN
// Unfortunately, the INFINITY macro cannot be used with the '-pedantic'
// warning flag and certain versions of GCC due to a bug:
// http://gcc.gnu.org/bugzilla/show_bug.cgi?id=11931
// For now, we use the more involved template-based version from <limits>, but
// only when compiling with GCC versions affected by the bug (2.96.x - 4.0.x)
#if V8_CC_GNU && V8_GNUC_PREREQ(2, 96, 0) && !V8_GNUC_PREREQ(4, 1, 0)
# include <limits> // NOLINT
# define V8_INFINITY std::numeric_limits<double>::infinity()
#elif V8_LIBC_MSVCRT
# define V8_INFINITY HUGE_VAL
#elif V8_OS_AIX
#define V8_INFINITY (__builtin_inff())
#else
# define V8_INFINITY INFINITY
#endif
namespace v8 {
namespace base {
class Mutex;
class RecursiveMutex;
class VirtualMemory;
}
namespace internal {
// Determine whether we are running in a simulated environment.
// Setting USE_SIMULATOR explicitly from the build script will force
// the use of a simulated environment.
#if !defined(USE_SIMULATOR)
#if (V8_TARGET_ARCH_ARM64 && !V8_HOST_ARCH_ARM64)
#define USE_SIMULATOR 1
#endif
#if (V8_TARGET_ARCH_ARM && !V8_HOST_ARCH_ARM)
#define USE_SIMULATOR 1
#endif
#if (V8_TARGET_ARCH_PPC && !V8_HOST_ARCH_PPC)
#define USE_SIMULATOR 1
#endif
#if (V8_TARGET_ARCH_MIPS && !V8_HOST_ARCH_MIPS)
#define USE_SIMULATOR 1
#endif
#if (V8_TARGET_ARCH_MIPS64 && !V8_HOST_ARCH_MIPS64)
#define USE_SIMULATOR 1
#endif
#if (V8_TARGET_ARCH_S390 && !V8_HOST_ARCH_S390)
#define USE_SIMULATOR 1
#endif
#endif
// Determine whether the architecture uses an embedded constant pool
// (contiguous constant pool embedded in code object).
#if V8_TARGET_ARCH_PPC
#define V8_EMBEDDED_CONSTANT_POOL 1
#else
#define V8_EMBEDDED_CONSTANT_POOL 0
#endif
#ifdef V8_TARGET_ARCH_ARM
// Set stack limit lower for ARM than for other architectures because
// stack allocating MacroAssembler takes 120K bytes.
// See issue crbug.com/405338
#define V8_DEFAULT_STACK_SIZE_KB 864
#else
// Slightly less than 1MB, since Windows' default stack size for
// the main execution thread is 1MB for both 32 and 64-bit.
#define V8_DEFAULT_STACK_SIZE_KB 984
#endif
// Determine whether double field unboxing feature is enabled.
#if V8_TARGET_ARCH_64_BIT
#define V8_DOUBLE_FIELDS_UNBOXING 1
#else
#define V8_DOUBLE_FIELDS_UNBOXING 0
#endif
typedef uint8_t byte;
typedef byte* Address;
// -----------------------------------------------------------------------------
// Constants
const int KB = 1024;
const int MB = KB * KB;
const int GB = KB * KB * KB;
const int kMaxInt = 0x7FFFFFFF;
const int kMinInt = -kMaxInt - 1;
const int kMaxInt8 = (1 << 7) - 1;
const int kMinInt8 = -(1 << 7);
const int kMaxUInt8 = (1 << 8) - 1;
const int kMinUInt8 = 0;
const int kMaxInt16 = (1 << 15) - 1;
const int kMinInt16 = -(1 << 15);
const int kMaxUInt16 = (1 << 16) - 1;
const int kMinUInt16 = 0;
const uint32_t kMaxUInt32 = 0xFFFFFFFFu;
const int kMinUInt32 = 0;
const int kCharSize = sizeof(char);
const int kShortSize = sizeof(short); // NOLINT
const int kIntSize = sizeof(int);
const int kInt32Size = sizeof(int32_t);
const int kInt64Size = sizeof(int64_t);
const int kSizetSize = sizeof(size_t);
const int kFloatSize = sizeof(float);
const int kDoubleSize = sizeof(double);
const int kIntptrSize = sizeof(intptr_t);
const int kPointerSize = sizeof(void*);
#if V8_TARGET_ARCH_X64 && V8_TARGET_ARCH_32_BIT
const int kRegisterSize = kPointerSize + kPointerSize;
#else
const int kRegisterSize = kPointerSize;
#endif
const int kPCOnStackSize = kRegisterSize;
const int kFPOnStackSize = kRegisterSize;
#if V8_TARGET_ARCH_X64 || V8_TARGET_ARCH_IA32 || V8_TARGET_ARCH_X87
const int kElidedFrameSlots = kPCOnStackSize / kPointerSize;
#else
const int kElidedFrameSlots = 0;
#endif
const int kDoubleSizeLog2 = 3;
#if V8_HOST_ARCH_64_BIT
const int kPointerSizeLog2 = 3;
const intptr_t kIntptrSignBit = V8_INT64_C(0x8000000000000000);
const uintptr_t kUintptrAllBitsSet = V8_UINT64_C(0xFFFFFFFFFFFFFFFF);
const bool kRequiresCodeRange = true;
#if V8_TARGET_ARCH_MIPS64
// To use pseudo-relative jumps such as j/jal instructions which have 28-bit
// encoded immediate, the addresses have to be in range of 256MB aligned
// region. Used only for large object space.
const size_t kMaximalCodeRangeSize = 256 * MB;
const size_t kCodeRangeAreaAlignment = 256 * MB;
#elif V8_HOST_ARCH_PPC && V8_TARGET_ARCH_PPC && V8_OS_LINUX
const size_t kMaximalCodeRangeSize = 512 * MB;
const size_t kCodeRangeAreaAlignment = 64 * KB; // OS page on PPC Linux
#else
const size_t kMaximalCodeRangeSize = 512 * MB;
const size_t kCodeRangeAreaAlignment = 4 * KB; // OS page.
#endif
#if V8_OS_WIN
const size_t kMinimumCodeRangeSize = 4 * MB;
const size_t kReservedCodeRangePages = 1;
#else
const size_t kMinimumCodeRangeSize = 3 * MB;
const size_t kReservedCodeRangePages = 0;
#endif
#else
const int kPointerSizeLog2 = 2;
const intptr_t kIntptrSignBit = 0x80000000;
const uintptr_t kUintptrAllBitsSet = 0xFFFFFFFFu;
#if V8_TARGET_ARCH_X64 && V8_TARGET_ARCH_32_BIT
// x32 port also requires code range.
const bool kRequiresCodeRange = true;
const size_t kMaximalCodeRangeSize = 256 * MB;
const size_t kMinimumCodeRangeSize = 3 * MB;
const size_t kCodeRangeAreaAlignment = 4 * KB; // OS page.
#elif V8_HOST_ARCH_PPC && V8_TARGET_ARCH_PPC && V8_OS_LINUX
const bool kRequiresCodeRange = false;
const size_t kMaximalCodeRangeSize = 0 * MB;
const size_t kMinimumCodeRangeSize = 0 * MB;
const size_t kCodeRangeAreaAlignment = 64 * KB; // OS page on PPC Linux
#else
const bool kRequiresCodeRange = false;
const size_t kMaximalCodeRangeSize = 0 * MB;
const size_t kMinimumCodeRangeSize = 0 * MB;
const size_t kCodeRangeAreaAlignment = 4 * KB; // OS page.
#endif
const size_t kReservedCodeRangePages = 0;
#endif
// Trigger an incremental GCs once the external memory reaches this limit.
const int kExternalAllocationSoftLimit = 64 * MB;
// Maximum object size that gets allocated into regular pages. Objects larger
// than that size are allocated in large object space and are never moved in
// memory. This also applies to new space allocation, since objects are never
// migrated from new space to large object space. Takes double alignment into
// account.
//
// Current value: Page::kAllocatableMemory (on 32-bit arch) - 512 (slack).
const int kMaxRegularHeapObjectSize = 507136;
STATIC_ASSERT(kPointerSize == (1 << kPointerSizeLog2));
const int kBitsPerByte = 8;
const int kBitsPerByteLog2 = 3;
const int kBitsPerPointer = kPointerSize * kBitsPerByte;
const int kBitsPerInt = kIntSize * kBitsPerByte;
// IEEE 754 single precision floating point number bit layout.
const uint32_t kBinary32SignMask = 0x80000000u;
const uint32_t kBinary32ExponentMask = 0x7f800000u;
const uint32_t kBinary32MantissaMask = 0x007fffffu;
const int kBinary32ExponentBias = 127;
const int kBinary32MaxExponent = 0xFE;
const int kBinary32MinExponent = 0x01;
const int kBinary32MantissaBits = 23;
const int kBinary32ExponentShift = 23;
// Quiet NaNs have bits 51 to 62 set, possibly the sign bit, and no
// other bits set.
const uint64_t kQuietNaNMask = static_cast<uint64_t>(0xfff) << 51;
// Latin1/UTF-16 constants
// Code-point values in Unicode 4.0 are 21 bits wide.
// Code units in UTF-16 are 16 bits wide.
typedef uint16_t uc16;
typedef int32_t uc32;
const int kOneByteSize = kCharSize;
const int kUC16Size = sizeof(uc16); // NOLINT
// 128 bit SIMD value size.
const int kSimd128Size = 16;
// Round up n to be a multiple of sz, where sz is a power of 2.
#define ROUND_UP(n, sz) (((n) + ((sz) - 1)) & ~((sz) - 1))
// FUNCTION_ADDR(f) gets the address of a C function f.
#define FUNCTION_ADDR(f) \
(reinterpret_cast<v8::internal::Address>(reinterpret_cast<intptr_t>(f)))
// FUNCTION_CAST<F>(addr) casts an address into a function
// of type F. Used to invoke generated code from within C.
template <typename F>
F FUNCTION_CAST(Address addr) {
return reinterpret_cast<F>(reinterpret_cast<intptr_t>(addr));
}
// Determine whether the architecture uses function descriptors
// which provide a level of indirection between the function pointer
// and the function entrypoint.
#if V8_HOST_ARCH_PPC && \
(V8_OS_AIX || (V8_TARGET_ARCH_PPC64 && V8_TARGET_BIG_ENDIAN))
#define USES_FUNCTION_DESCRIPTORS 1
#define FUNCTION_ENTRYPOINT_ADDRESS(f) \
(reinterpret_cast<v8::internal::Address*>( \
&(reinterpret_cast<intptr_t*>(f)[0])))
#else
#define USES_FUNCTION_DESCRIPTORS 0
#endif
// -----------------------------------------------------------------------------
// Forward declarations for frequently used classes
// (sorted alphabetically)
class FreeStoreAllocationPolicy;
template <typename T, class P = FreeStoreAllocationPolicy> class List;
// -----------------------------------------------------------------------------
// Declarations for use in both the preparser and the rest of V8.
// The Strict Mode (ECMA-262 5th edition, 4.2.2).
enum LanguageMode : uint32_t { SLOPPY, STRICT, LANGUAGE_END };
inline std::ostream& operator<<(std::ostream& os, const LanguageMode& mode) {
switch (mode) {
case SLOPPY: return os << "sloppy";
case STRICT: return os << "strict";
default: UNREACHABLE();
}
return os;
}
inline bool is_sloppy(LanguageMode language_mode) {
return language_mode == SLOPPY;
}
inline bool is_strict(LanguageMode language_mode) {
return language_mode != SLOPPY;
}
inline bool is_valid_language_mode(int language_mode) {
return language_mode == SLOPPY || language_mode == STRICT;
}
inline LanguageMode construct_language_mode(bool strict_bit) {
return static_cast<LanguageMode>(strict_bit);
}
// This constant is used as an undefined value when passing source positions.
const int kNoSourcePosition = -1;
// This constant is used to indicate missing deoptimization information.
const int kNoDeoptimizationId = -1;
// Mask for the sign bit in a smi.
const intptr_t kSmiSignMask = kIntptrSignBit;
const int kObjectAlignmentBits = kPointerSizeLog2;
const intptr_t kObjectAlignment = 1 << kObjectAlignmentBits;
const intptr_t kObjectAlignmentMask = kObjectAlignment - 1;
// Desired alignment for pointers.
const intptr_t kPointerAlignment = (1 << kPointerSizeLog2);
const intptr_t kPointerAlignmentMask = kPointerAlignment - 1;
// Desired alignment for double values.
const intptr_t kDoubleAlignment = 8;
const intptr_t kDoubleAlignmentMask = kDoubleAlignment - 1;
// Desired alignment for 128 bit SIMD values.
const intptr_t kSimd128Alignment = 16;
const intptr_t kSimd128AlignmentMask = kSimd128Alignment - 1;
// Desired alignment for generated code is 32 bytes (to improve cache line
// utilization).
const int kCodeAlignmentBits = 5;
const intptr_t kCodeAlignment = 1 << kCodeAlignmentBits;
const intptr_t kCodeAlignmentMask = kCodeAlignment - 1;
// The owner field of a page is tagged with the page header tag. We need that
// to find out if a slot is part of a large object. If we mask out the lower
// 0xfffff bits (1M pages), go to the owner offset, and see that this field
// is tagged with the page header tag, we can just look up the owner.
// Otherwise, we know that we are somewhere (not within the first 1M) in a
// large object.
const int kPageHeaderTag = 3;
const int kPageHeaderTagSize = 2;
const intptr_t kPageHeaderTagMask = (1 << kPageHeaderTagSize) - 1;
// Zap-value: The value used for zapping dead objects.
// Should be a recognizable hex value tagged as a failure.
#ifdef V8_HOST_ARCH_64_BIT
const Address kZapValue =
reinterpret_cast<Address>(V8_UINT64_C(0xdeadbeedbeadbeef));
const Address kHandleZapValue =
reinterpret_cast<Address>(V8_UINT64_C(0x1baddead0baddeaf));
const Address kGlobalHandleZapValue =
reinterpret_cast<Address>(V8_UINT64_C(0x1baffed00baffedf));
const Address kFromSpaceZapValue =
reinterpret_cast<Address>(V8_UINT64_C(0x1beefdad0beefdaf));
const uint64_t kDebugZapValue = V8_UINT64_C(0xbadbaddbbadbaddb);
const uint64_t kSlotsZapValue = V8_UINT64_C(0xbeefdeadbeefdeef);
const uint64_t kFreeListZapValue = 0xfeed1eaffeed1eaf;
#else
const Address kZapValue = reinterpret_cast<Address>(0xdeadbeef);
const Address kHandleZapValue = reinterpret_cast<Address>(0xbaddeaf);
const Address kGlobalHandleZapValue = reinterpret_cast<Address>(0xbaffedf);
const Address kFromSpaceZapValue = reinterpret_cast<Address>(0xbeefdaf);
const uint32_t kSlotsZapValue = 0xbeefdeef;
const uint32_t kDebugZapValue = 0xbadbaddb;
const uint32_t kFreeListZapValue = 0xfeed1eaf;
#endif
const int kCodeZapValue = 0xbadc0de;
const uint32_t kPhantomReferenceZap = 0xca11bac;
// On Intel architecture, cache line size is 64 bytes.
// On ARM it may be less (32 bytes), but as far this constant is
// used for aligning data, it doesn't hurt to align on a greater value.
#define PROCESSOR_CACHE_LINE_SIZE 64
// Constants relevant to double precision floating point numbers.
// If looking only at the top 32 bits, the QNaN mask is bits 19 to 30.
const uint32_t kQuietNaNHighBitsMask = 0xfff << (51 - 32);
// -----------------------------------------------------------------------------
// Forward declarations for frequently used classes
class AccessorInfo;
class Allocation;
class Arguments;
class Assembler;
class Code;
class CodeGenerator;
class CodeStub;
class Context;
class Debug;
class DebugInfo;
class Descriptor;
class DescriptorArray;
class TransitionArray;
class ExternalReference;
class FixedArray;
class FunctionTemplateInfo;
class MemoryChunk;
class SeededNumberDictionary;
class UnseededNumberDictionary;
class NameDictionary;
class GlobalDictionary;
template <typename T> class MaybeHandle;
template <typename T> class Handle;
class Heap;
class HeapObject;
class IC;
class InterceptorInfo;
class Isolate;
class JSReceiver;
class JSArray;
class JSFunction;
class JSObject;
class LargeObjectSpace;
class MacroAssembler;
class Map;
class MapSpace;
class MarkCompactCollector;
class NewSpace;
class Object;
class OldSpace;
class ParameterCount;
class Foreign;
class Scope;
class DeclarationScope;
class ModuleScope;
class ScopeInfo;
class Script;
class Smi;
template <typename Config, class Allocator = FreeStoreAllocationPolicy>
class SplayTree;
class String;
class Symbol;
class Name;
class Struct;
class TypeFeedbackVector;
class Variable;
class RelocInfo;
class Deserializer;
class MessageLocation;
typedef bool (*WeakSlotCallback)(Object** pointer);
typedef bool (*WeakSlotCallbackWithHeap)(Heap* heap, Object** pointer);
// -----------------------------------------------------------------------------
// Miscellaneous
// NOTE: SpaceIterator depends on AllocationSpace enumeration values being
// consecutive.
// Keep this enum in sync with the ObjectSpace enum in v8.h
enum AllocationSpace {
NEW_SPACE, // Semispaces collected with copying collector.
OLD_SPACE, // May contain pointers to new space.
CODE_SPACE, // No pointers to new space, marked executable.
MAP_SPACE, // Only and all map objects.
LO_SPACE, // Promoted large objects.
FIRST_SPACE = NEW_SPACE,
LAST_SPACE = LO_SPACE,
FIRST_PAGED_SPACE = OLD_SPACE,
LAST_PAGED_SPACE = MAP_SPACE
};
const int kSpaceTagSize = 3;
const int kSpaceTagMask = (1 << kSpaceTagSize) - 1;
enum AllocationAlignment {
kWordAligned,
kDoubleAligned,
kDoubleUnaligned,
kSimd128Unaligned
};
// Possible outcomes for decisions.
enum class Decision : uint8_t { kUnknown, kTrue, kFalse };
inline size_t hash_value(Decision decision) {
return static_cast<uint8_t>(decision);
}
inline std::ostream& operator<<(std::ostream& os, Decision decision) {
switch (decision) {
case Decision::kUnknown:
return os << "Unknown";
case Decision::kTrue:
return os << "True";
case Decision::kFalse:
return os << "False";
}
UNREACHABLE();
return os;
}
// Supported write barrier modes.
enum WriteBarrierKind : uint8_t {
kNoWriteBarrier,
kMapWriteBarrier,
kPointerWriteBarrier,
kFullWriteBarrier
};
inline size_t hash_value(WriteBarrierKind kind) {
return static_cast<uint8_t>(kind);
}
inline std::ostream& operator<<(std::ostream& os, WriteBarrierKind kind) {
switch (kind) {
case kNoWriteBarrier:
return os << "NoWriteBarrier";
case kMapWriteBarrier:
return os << "MapWriteBarrier";
case kPointerWriteBarrier:
return os << "PointerWriteBarrier";
case kFullWriteBarrier:
return os << "FullWriteBarrier";
}
UNREACHABLE();
return os;
}
// A flag that indicates whether objects should be pretenured when
// allocated (allocated directly into the old generation) or not
// (allocated in the young generation if the object size and type
// allows).
enum PretenureFlag { NOT_TENURED, TENURED };
inline std::ostream& operator<<(std::ostream& os, const PretenureFlag& flag) {
switch (flag) {
case NOT_TENURED:
return os << "NotTenured";
case TENURED:
return os << "Tenured";
}
UNREACHABLE();
return os;
}
enum MinimumCapacity {
USE_DEFAULT_MINIMUM_CAPACITY,
USE_CUSTOM_MINIMUM_CAPACITY
};
enum GarbageCollector { SCAVENGER, MARK_COMPACTOR, MINOR_MARK_COMPACTOR };
enum Executability { NOT_EXECUTABLE, EXECUTABLE };
enum VisitMode {
VISIT_ALL,
VISIT_ALL_IN_SCAVENGE,
VISIT_ALL_IN_SWEEP_NEWSPACE,
VISIT_ONLY_STRONG,
VISIT_ONLY_STRONG_FOR_SERIALIZATION,
VISIT_ONLY_STRONG_ROOT_LIST,
};
// Flag indicating whether code is built into the VM (one of the natives files).
enum NativesFlag { NOT_NATIVES_CODE, EXTENSION_CODE, NATIVES_CODE };
// JavaScript defines two kinds of 'nil'.
enum NilValue { kNullValue, kUndefinedValue };
// ParseRestriction is used to restrict the set of valid statements in a
// unit of compilation. Restriction violations cause a syntax error.
enum ParseRestriction {
NO_PARSE_RESTRICTION, // All expressions are allowed.
ONLY_SINGLE_FUNCTION_LITERAL // Only a single FunctionLiteral expression.
};
// TODO(gsathya): Move this to JSPromise once we create it.
// This should be in sync with the constants in promise.js
enum PromiseStatus {
kPromisePending,
kPromiseFulfilled,
kPromiseRejected,
};
// A CodeDesc describes a buffer holding instructions and relocation
// information. The instructions start at the beginning of the buffer
// and grow forward, the relocation information starts at the end of
// the buffer and grows backward. A constant pool may exist at the
// end of the instructions.
//
// |<--------------- buffer_size ----------------------------------->|
// |<------------- instr_size ---------->| |<-- reloc_size -->|
// | |<- const_pool_size ->| |
// +=====================================+========+==================+
// | instructions | data | free | reloc info |
// +=====================================+========+==================+
// ^
// |
// buffer
struct CodeDesc {
byte* buffer;
int buffer_size;
int instr_size;
int reloc_size;
int constant_pool_size;
byte* unwinding_info;
int unwinding_info_size;
Assembler* origin;
};
// Callback function used for checking constraints when copying/relocating
// objects. Returns true if an object can be copied/relocated from its
// old_addr to a new_addr.
typedef bool (*ConstraintCallback)(Address new_addr, Address old_addr);
// Callback function on inline caches, used for iterating over inline caches
// in compiled code.
typedef void (*InlineCacheCallback)(Code* code, Address ic);
// State for inline cache call sites. Aliased as IC::State.
enum InlineCacheState {
// Has never been executed.
UNINITIALIZED,
// Has been executed but monomorhic state has been delayed.
PREMONOMORPHIC,
// Has been executed and only one receiver type has been seen.
MONOMORPHIC,
// Check failed due to prototype (or map deprecation).
RECOMPUTE_HANDLER,
// Multiple receiver types have been seen.
POLYMORPHIC,
// Many receiver types have been seen.
MEGAMORPHIC,
// A generic handler is installed and no extra typefeedback is recorded.
GENERIC,
};
enum CacheHolderFlag {
kCacheOnPrototype,
kCacheOnPrototypeReceiverIsDictionary,
kCacheOnPrototypeReceiverIsPrimitive,
kCacheOnReceiver
};
enum WhereToStart { kStartAtReceiver, kStartAtPrototype };
// The Store Buffer (GC).
typedef enum {
kStoreBufferFullEvent,
kStoreBufferStartScanningPagesEvent,
kStoreBufferScanningPageEvent
} StoreBufferEvent;
typedef void (*StoreBufferCallback)(Heap* heap,
MemoryChunk* page,
StoreBufferEvent event);
// Union used for customized checking of the IEEE double types
// inlined within v8 runtime, rather than going to the underlying
// platform headers and libraries
union IeeeDoubleLittleEndianArchType {
double d;
struct {
unsigned int man_low :32;
unsigned int man_high :20;
unsigned int exp :11;
unsigned int sign :1;
} bits;
};
union IeeeDoubleBigEndianArchType {
double d;
struct {
unsigned int sign :1;
unsigned int exp :11;
unsigned int man_high :20;
unsigned int man_low :32;
} bits;
};
#if V8_TARGET_LITTLE_ENDIAN
typedef IeeeDoubleLittleEndianArchType IeeeDoubleArchType;
const int kIeeeDoubleMantissaWordOffset = 0;
const int kIeeeDoubleExponentWordOffset = 4;
#else
typedef IeeeDoubleBigEndianArchType IeeeDoubleArchType;
const int kIeeeDoubleMantissaWordOffset = 4;
const int kIeeeDoubleExponentWordOffset = 0;
#endif
// AccessorCallback
struct AccessorDescriptor {
Object* (*getter)(Isolate* isolate, Object* object, void* data);
Object* (*setter)(
Isolate* isolate, JSObject* object, Object* value, void* data);
void* data;
};
// -----------------------------------------------------------------------------
// Macros
// Testers for test.
#define HAS_SMI_TAG(value) \
((reinterpret_cast<intptr_t>(value) & kSmiTagMask) == kSmiTag)
// OBJECT_POINTER_ALIGN returns the value aligned as a HeapObject pointer
#define OBJECT_POINTER_ALIGN(value) \
(((value) + kObjectAlignmentMask) & ~kObjectAlignmentMask)
// POINTER_SIZE_ALIGN returns the value aligned as a pointer.
#define POINTER_SIZE_ALIGN(value) \
(((value) + kPointerAlignmentMask) & ~kPointerAlignmentMask)
// CODE_POINTER_ALIGN returns the value aligned as a generated code segment.
#define CODE_POINTER_ALIGN(value) \
(((value) + kCodeAlignmentMask) & ~kCodeAlignmentMask)
// DOUBLE_POINTER_ALIGN returns the value algined for double pointers.
#define DOUBLE_POINTER_ALIGN(value) \
(((value) + kDoubleAlignmentMask) & ~kDoubleAlignmentMask)
// CPU feature flags.
enum CpuFeature {
// x86
SSE4_1,
SSSE3,
SSE3,
SAHF,
AVX,
FMA3,
BMI1,
BMI2,
LZCNT,
POPCNT,
ATOM,
// ARM
// - Standard configurations. The baseline is ARMv6+VFPv2.
ARMv7, // ARMv7-A + VFPv3-D32 + NEON
ARMv7_SUDIV, // ARMv7-A + VFPv4-D32 + NEON + SUDIV
ARMv8, // ARMv8-A (+ all of the above)
// MIPS, MIPS64
FPU,
FP64FPU,
MIPSr1,
MIPSr2,
MIPSr6,
// ARM64
ALWAYS_ALIGN_CSP,
// PPC
FPR_GPR_MOV,
LWSYNC,
ISELECT,
// S390
DISTINCT_OPS,
GENERAL_INSTR_EXT,
FLOATING_POINT_EXT,
NUMBER_OF_CPU_FEATURES,
// ARM feature aliases (based on the standard configurations above).
VFPv3 = ARMv7,
NEON = ARMv7,
VFP32DREGS = ARMv7,
SUDIV = ARMv7_SUDIV
};
// Defines hints about receiver values based on structural knowledge.
enum class ConvertReceiverMode : unsigned {
kNullOrUndefined, // Guaranteed to be null or undefined.
kNotNullOrUndefined, // Guaranteed to never be null or undefined.
kAny // No specific knowledge about receiver.
};
inline size_t hash_value(ConvertReceiverMode mode) {
return bit_cast<unsigned>(mode);
}
inline std::ostream& operator<<(std::ostream& os, ConvertReceiverMode mode) {
switch (mode) {
case ConvertReceiverMode::kNullOrUndefined:
return os << "NULL_OR_UNDEFINED";
case ConvertReceiverMode::kNotNullOrUndefined:
return os << "NOT_NULL_OR_UNDEFINED";
case ConvertReceiverMode::kAny:
return os << "ANY";
}
UNREACHABLE();
return os;
}
// Defines whether tail call optimization is allowed.
enum class TailCallMode : unsigned { kAllow, kDisallow };
inline size_t hash_value(TailCallMode mode) { return bit_cast<unsigned>(mode); }
inline std::ostream& operator<<(std::ostream& os, TailCallMode mode) {
switch (mode) {
case TailCallMode::kAllow:
return os << "ALLOW_TAIL_CALLS";
case TailCallMode::kDisallow:
return os << "DISALLOW_TAIL_CALLS";
}
UNREACHABLE();
return os;
}
// Valid hints for the abstract operation OrdinaryToPrimitive,
// implemented according to ES6, section 7.1.1.
enum class OrdinaryToPrimitiveHint { kNumber, kString };
// Valid hints for the abstract operation ToPrimitive,
// implemented according to ES6, section 7.1.1.
enum class ToPrimitiveHint { kDefault, kNumber, kString };
// Defines specifics about arguments object or rest parameter creation.
enum class CreateArgumentsType : uint8_t {
kMappedArguments,
kUnmappedArguments,
kRestParameter
};
inline size_t hash_value(CreateArgumentsType type) {
return bit_cast<uint8_t>(type);
}
inline std::ostream& operator<<(std::ostream& os, CreateArgumentsType type) {
switch (type) {
case CreateArgumentsType::kMappedArguments:
return os << "MAPPED_ARGUMENTS";
case CreateArgumentsType::kUnmappedArguments:
return os << "UNMAPPED_ARGUMENTS";
case CreateArgumentsType::kRestParameter:
return os << "REST_PARAMETER";
}
UNREACHABLE();
return os;
}
// Used to specify if a macro instruction must perform a smi check on tagged
// values.
enum SmiCheckType {
DONT_DO_SMI_CHECK,
DO_SMI_CHECK
};
enum ScopeType : uint8_t {
EVAL_SCOPE, // The top-level scope for an eval source.
FUNCTION_SCOPE, // The top-level scope for a function.
MODULE_SCOPE, // The scope introduced by a module literal
SCRIPT_SCOPE, // The top-level scope for a script or a top-level eval.
CATCH_SCOPE, // The scope introduced by catch.
BLOCK_SCOPE, // The scope introduced by a new block.
WITH_SCOPE // The scope introduced by with.
};
// The mips architecture prior to revision 5 has inverted encoding for sNaN.
// The x87 FPU convert the sNaN to qNaN automatically when loading sNaN from
// memmory.
// Use mips sNaN which is a not used qNaN in x87 port as sNaN to workaround this
// issue
// for some test cases.
#if (V8_TARGET_ARCH_MIPS && !defined(_MIPS_ARCH_MIPS32R6) && \
(!defined(USE_SIMULATOR) || !defined(_MIPS_TARGET_SIMULATOR))) || \
(V8_TARGET_ARCH_MIPS64 && !defined(_MIPS_ARCH_MIPS64R6) && \
(!defined(USE_SIMULATOR) || !defined(_MIPS_TARGET_SIMULATOR))) || \
(V8_TARGET_ARCH_X87)
const uint32_t kHoleNanUpper32 = 0xFFFF7FFF;
const uint32_t kHoleNanLower32 = 0xFFFF7FFF;
#else
const uint32_t kHoleNanUpper32 = 0xFFF7FFFF;
const uint32_t kHoleNanLower32 = 0xFFF7FFFF;
#endif
const uint64_t kHoleNanInt64 =
(static_cast<uint64_t>(kHoleNanUpper32) << 32) | kHoleNanLower32;
// ES6 section 20.1.2.6 Number.MAX_SAFE_INTEGER
const double kMaxSafeInteger = 9007199254740991.0; // 2^53-1
// The order of this enum has to be kept in sync with the predicates below.
enum VariableMode : uint8_t {
// User declared variables:
VAR, // declared via 'var', and 'function' declarations
LET, // declared via 'let' declarations (first lexical)
CONST, // declared via 'const' declarations (last lexical)
// Variables introduced by the compiler:
TEMPORARY, // temporary variables (not user-visible), stack-allocated
// unless the scope as a whole has forced context allocation
DYNAMIC, // always require dynamic lookup (we don't know
// the declaration)
DYNAMIC_GLOBAL, // requires dynamic lookup, but we know that the
// variable is global unless it has been shadowed
// by an eval-introduced variable
DYNAMIC_LOCAL, // requires dynamic lookup, but we know that the
// variable is local and where it is unless it
// has been shadowed by an eval-introduced
// variable
kLastVariableMode = DYNAMIC_LOCAL
};
// Printing support
#ifdef DEBUG
inline const char* VariableMode2String(VariableMode mode) {
switch (mode) {
case VAR:
return "VAR";
case LET:
return "LET";
case CONST:
return "CONST";
case DYNAMIC:
return "DYNAMIC";
case DYNAMIC_GLOBAL:
return "DYNAMIC_GLOBAL";
case DYNAMIC_LOCAL:
return "DYNAMIC_LOCAL";
case TEMPORARY:
return "TEMPORARY";
}
UNREACHABLE();
return NULL;
}
#endif
enum VariableKind : uint8_t {
NORMAL_VARIABLE,
FUNCTION_VARIABLE,
THIS_VARIABLE,
SLOPPY_FUNCTION_NAME_VARIABLE,
kLastKind = SLOPPY_FUNCTION_NAME_VARIABLE
};
inline bool IsDynamicVariableMode(VariableMode mode) {
return mode >= DYNAMIC && mode <= DYNAMIC_LOCAL;
}
inline bool IsDeclaredVariableMode(VariableMode mode) {
STATIC_ASSERT(VAR == 0); // Implies that mode >= VAR.
return mode <= CONST;
}
inline bool IsLexicalVariableMode(VariableMode mode) {
return mode >= LET && mode <= CONST;
}
enum VariableLocation : uint8_t {
// Before and during variable allocation, a variable whose location is
// not yet determined. After allocation, a variable looked up as a
// property on the global object (and possibly absent). name() is the
// variable name, index() is invalid.
UNALLOCATED,
// A slot in the parameter section on the stack. index() is the
// parameter index, counting left-to-right. The receiver is index -1;
// the first parameter is index 0.
PARAMETER,
// A slot in the local section on the stack. index() is the variable
// index in the stack frame, starting at 0.
LOCAL,
// An indexed slot in a heap context. index() is the variable index in
// the context object on the heap, starting at 0. scope() is the
// corresponding scope.
CONTEXT,
// A named slot in a heap context. name() is the variable name in the
// context object on the heap, with lookup starting at the current
// context. index() is invalid.
LOOKUP,
// A named slot in a module's export table.
MODULE,
kLastVariableLocation = MODULE
};
// ES6 Draft Rev3 10.2 specifies declarative environment records with mutable
// and immutable bindings that can be in two states: initialized and
// uninitialized. In ES5 only immutable bindings have these two states. When
// accessing a binding, it needs to be checked for initialization. However in
// the following cases the binding is initialized immediately after creation
// so the initialization check can always be skipped:
// 1. Var declared local variables.
// var foo;
// 2. A local variable introduced by a function declaration.
// function foo() {}
// 3. Parameters
// function x(foo) {}
// 4. Catch bound variables.
// try {} catch (foo) {}
// 6. Function variables of named function expressions.
// var x = function foo() {}
// 7. Implicit binding of 'this'.
// 8. Implicit binding of 'arguments' in functions.
//
// ES5 specified object environment records which are introduced by ES elements
// such as Program and WithStatement that associate identifier bindings with the
// properties of some object. In the specification only mutable bindings exist
// (which may be non-writable) and have no distinct initialization step. However
// V8 allows const declarations in global code with distinct creation and
// initialization steps which are represented by non-writable properties in the
// global object. As a result also these bindings need to be checked for
// initialization.
//
// The following enum specifies a flag that indicates if the binding needs a
// distinct initialization step (kNeedsInitialization) or if the binding is
// immediately initialized upon creation (kCreatedInitialized).
enum InitializationFlag : uint8_t { kNeedsInitialization, kCreatedInitialized };
enum class HoleCheckMode { kRequired, kElided };
enum MaybeAssignedFlag : uint8_t { kNotAssigned, kMaybeAssigned };
// Serialized in PreparseData, so numeric values should not be changed.
enum ParseErrorType { kSyntaxError = 0, kReferenceError = 1 };
enum MinusZeroMode {
TREAT_MINUS_ZERO_AS_ZERO,
FAIL_ON_MINUS_ZERO
};
enum Signedness { kSigned, kUnsigned };
enum FunctionKind : uint16_t {
kNormalFunction = 0,
kArrowFunction = 1 << 0,
kGeneratorFunction = 1 << 1,
kConciseMethod = 1 << 2,
kConciseGeneratorMethod = kGeneratorFunction | kConciseMethod,
kDefaultConstructor = 1 << 3,
kSubclassConstructor = 1 << 4,
kBaseConstructor = 1 << 5,
kGetterFunction = 1 << 6,
kSetterFunction = 1 << 7,
kAsyncFunction = 1 << 8,
kModule = 1 << 9,
kAccessorFunction = kGetterFunction | kSetterFunction,
kDefaultBaseConstructor = kDefaultConstructor | kBaseConstructor,
kDefaultSubclassConstructor = kDefaultConstructor | kSubclassConstructor,
kClassConstructor =
kBaseConstructor | kSubclassConstructor | kDefaultConstructor,
kAsyncArrowFunction = kArrowFunction | kAsyncFunction,
kAsyncConciseMethod = kAsyncFunction | kConciseMethod
};
inline bool IsValidFunctionKind(FunctionKind kind) {
return kind == FunctionKind::kNormalFunction ||
kind == FunctionKind::kArrowFunction ||
kind == FunctionKind::kGeneratorFunction ||
kind == FunctionKind::kModule ||
kind == FunctionKind::kConciseMethod ||
kind == FunctionKind::kConciseGeneratorMethod ||
kind == FunctionKind::kGetterFunction ||
kind == FunctionKind::kSetterFunction ||
kind == FunctionKind::kAccessorFunction ||
kind == FunctionKind::kDefaultBaseConstructor ||
kind == FunctionKind::kDefaultSubclassConstructor ||
kind == FunctionKind::kBaseConstructor ||
kind == FunctionKind::kSubclassConstructor ||
kind == FunctionKind::kAsyncFunction ||
kind == FunctionKind::kAsyncArrowFunction ||
kind == FunctionKind::kAsyncConciseMethod;
}
inline bool IsArrowFunction(FunctionKind kind) {
DCHECK(IsValidFunctionKind(kind));
return kind & FunctionKind::kArrowFunction;
}
inline bool IsGeneratorFunction(FunctionKind kind) {
DCHECK(IsValidFunctionKind(kind));
return kind & FunctionKind::kGeneratorFunction;
}
inline bool IsModule(FunctionKind kind) {
DCHECK(IsValidFunctionKind(kind));
return kind & FunctionKind::kModule;
}
inline bool IsAsyncFunction(FunctionKind kind) {
DCHECK(IsValidFunctionKind(kind));
return kind & FunctionKind::kAsyncFunction;
}
inline bool IsResumableFunction(FunctionKind kind) {
return IsGeneratorFunction(kind) || IsAsyncFunction(kind) || IsModule(kind);
}
inline bool IsConciseMethod(FunctionKind kind) {
DCHECK(IsValidFunctionKind(kind));
return kind & FunctionKind::kConciseMethod;
}
inline bool IsGetterFunction(FunctionKind kind) {
DCHECK(IsValidFunctionKind(kind));
return kind & FunctionKind::kGetterFunction;
}
inline bool IsSetterFunction(FunctionKind kind) {
DCHECK(IsValidFunctionKind(kind));
return kind & FunctionKind::kSetterFunction;
}
inline bool IsAccessorFunction(FunctionKind kind) {
DCHECK(IsValidFunctionKind(kind));
return kind & FunctionKind::kAccessorFunction;
}
inline bool IsDefaultConstructor(FunctionKind kind) {
DCHECK(IsValidFunctionKind(kind));
return kind & FunctionKind::kDefaultConstructor;
}
inline bool IsBaseConstructor(FunctionKind kind) {
DCHECK(IsValidFunctionKind(kind));
return kind & FunctionKind::kBaseConstructor;
}
inline bool IsSubclassConstructor(FunctionKind kind) {
DCHECK(IsValidFunctionKind(kind));
return kind & FunctionKind::kSubclassConstructor;
}
inline bool IsClassConstructor(FunctionKind kind) {
DCHECK(IsValidFunctionKind(kind));
return kind & FunctionKind::kClassConstructor;
}
inline bool IsConstructable(FunctionKind kind, LanguageMode mode) {
if (IsAccessorFunction(kind)) return false;
if (IsConciseMethod(kind)) return false;
if (IsArrowFunction(kind)) return false;
if (IsGeneratorFunction(kind)) return false;
if (IsAsyncFunction(kind)) return false;
return true;
}
enum class CallableType : unsigned { kJSFunction, kAny };
inline size_t hash_value(CallableType type) { return bit_cast<unsigned>(type); }
inline std::ostream& operator<<(std::ostream& os, CallableType function_type) {
switch (function_type) {
case CallableType::kJSFunction:
return os << "JSFunction";
case CallableType::kAny:
return os << "Any";
}
UNREACHABLE();
return os;
}
inline uint32_t ObjectHash(Address address) {
// All objects are at least pointer aligned, so we can remove the trailing
// zeros.
return static_cast<uint32_t>(bit_cast<uintptr_t>(address) >>
kPointerSizeLog2);
}
// Type feedback is encoded in such a way that, we can combine the feedback
// at different points by performing an 'OR' operation. Type feedback moves
// to a more generic type when we combine feedback.
// kSignedSmall -> kNumber -> kNumberOrOddball -> kAny
// kString -> kAny
// TODO(mythria): Remove kNumber type when crankshaft can handle Oddballs
// similar to Numbers. We don't need kNumber feedback for Turbofan. Extra
// information about Number might reduce few instructions but causes more
// deopts. We collect Number only because crankshaft does not handle all
// cases of oddballs.
class BinaryOperationFeedback {
public:
enum {
kNone = 0x0,
kSignedSmall = 0x1,
kNumber = 0x3,
kNumberOrOddball = 0x7,
kString = 0x8,
kAny = 0x1F
};
};
// TODO(epertoso): consider unifying this with BinaryOperationFeedback.
class CompareOperationFeedback {
public:
enum { kNone = 0x00, kSignedSmall = 0x01, kNumber = 0x3, kAny = 0x7 };
};
// Describes how exactly a frame has been dropped from stack.
enum LiveEditFrameDropMode {
// No frame has been dropped.
LIVE_EDIT_FRAMES_UNTOUCHED,
// The top JS frame had been calling debug break slot stub. Patch the
// address this stub jumps to in the end.
LIVE_EDIT_FRAME_DROPPED_IN_DEBUG_SLOT_CALL,
// The top JS frame had been calling some C++ function. The return address
// gets patched automatically.
LIVE_EDIT_FRAME_DROPPED_IN_DIRECT_CALL,
LIVE_EDIT_FRAME_DROPPED_IN_RETURN_CALL,
LIVE_EDIT_CURRENTLY_SET_MODE
};
enum class UnicodeEncoding : uint8_t {
// Different unicode encodings in a |word32|:
UTF16, // hi 16bits -> trailing surrogate or 0, low 16bits -> lead surrogate
UTF32, // full UTF32 code unit / Unicode codepoint
};
inline size_t hash_value(UnicodeEncoding encoding) {
return static_cast<uint8_t>(encoding);
}
inline std::ostream& operator<<(std::ostream& os, UnicodeEncoding encoding) {
switch (encoding) {
case UnicodeEncoding::UTF16:
return os << "UTF16";
case UnicodeEncoding::UTF32:
return os << "UTF32";
}
UNREACHABLE();
return os;
}
enum class IterationKind { kKeys, kValues, kEntries };
inline std::ostream& operator<<(std::ostream& os, IterationKind kind) {
switch (kind) {
case IterationKind::kKeys:
return os << "IterationKind::kKeys";
case IterationKind::kValues:
return os << "IterationKind::kValues";
case IterationKind::kEntries:
return os << "IterationKind::kEntries";
}
UNREACHABLE();
return os;
}
} // namespace internal
} // namespace v8
// Used by js-builtin-reducer to identify whether ReduceArrayIterator() is
// reducing a JSArray method, or a JSTypedArray method.
enum class ArrayIteratorKind { kArray, kTypedArray };
namespace i = v8::internal;
#endif // V8_GLOBALS_H_