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// Copyright (c) 1994-2006 Sun Microsystems Inc.
// All Rights Reserved.
//
// Redistribution and use in source and binary forms, with or without
// modification, are permitted provided that the following conditions are
// met:
//
// - Redistributions of source code must retain the above copyright notice,
// this list of conditions and the following disclaimer.
//
// - Redistribution in binary form must reproduce the above copyright
// notice, this list of conditions and the following disclaimer in the
// documentation and/or other materials provided with the distribution.
//
// - Neither the name of Sun Microsystems or the names of contributors may
// be used to endorse or promote products derived from this software without
// specific prior written permission.
//
// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS
// IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,
// THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
// PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR
// CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
// EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
// PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
// PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
// LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
// NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
// SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
// The original source code covered by the above license above has been
// modified significantly by Google Inc.
// Copyright 2012 the V8 project authors. All rights reserved.
#ifndef V8_ASSEMBLER_H_
#define V8_ASSEMBLER_H_
#include "src/allocation.h"
#include "src/builtins/builtins.h"
#include "src/deoptimize-reason.h"
#include "src/globals.h"
#include "src/isolate.h"
#include "src/log.h"
#include "src/register-configuration.h"
#include "src/runtime/runtime.h"
namespace v8 {
// Forward declarations.
class ApiFunction;
namespace internal {
// Forward declarations.
class StatsCounter;
// -----------------------------------------------------------------------------
// Platform independent assembler base class.
enum class CodeObjectRequired { kNo, kYes };
class AssemblerBase: public Malloced {
public:
AssemblerBase(Isolate* isolate, void* buffer, int buffer_size);
virtual ~AssemblerBase();
Isolate* isolate() const { return isolate_; }
int jit_cookie() const { return jit_cookie_; }
bool emit_debug_code() const { return emit_debug_code_; }
void set_emit_debug_code(bool value) { emit_debug_code_ = value; }
bool serializer_enabled() const { return serializer_enabled_; }
void enable_serializer() { serializer_enabled_ = true; }
bool predictable_code_size() const { return predictable_code_size_; }
void set_predictable_code_size(bool value) { predictable_code_size_ = value; }
uint64_t enabled_cpu_features() const { return enabled_cpu_features_; }
void set_enabled_cpu_features(uint64_t features) {
enabled_cpu_features_ = features;
}
// Features are usually enabled by CpuFeatureScope, which also asserts that
// the features are supported before they are enabled.
bool IsEnabled(CpuFeature f) {
return (enabled_cpu_features_ & (static_cast<uint64_t>(1) << f)) != 0;
}
void EnableCpuFeature(CpuFeature f) {
enabled_cpu_features_ |= (static_cast<uint64_t>(1) << f);
}
bool is_constant_pool_available() const {
if (FLAG_enable_embedded_constant_pool) {
return constant_pool_available_;
} else {
// Embedded constant pool not supported on this architecture.
UNREACHABLE();
return false;
}
}
// Overwrite a host NaN with a quiet target NaN. Used by mksnapshot for
// cross-snapshotting.
static void QuietNaN(HeapObject* nan) { }
int pc_offset() const { return static_cast<int>(pc_ - buffer_); }
// This function is called when code generation is aborted, so that
// the assembler could clean up internal data structures.
virtual void AbortedCodeGeneration() { }
// Debugging
void Print();
static const int kMinimalBufferSize = 4*KB;
static void FlushICache(Isolate* isolate, void* start, size_t size);
protected:
// The buffer into which code and relocation info are generated. It could
// either be owned by the assembler or be provided externally.
byte* buffer_;
int buffer_size_;
bool own_buffer_;
void set_constant_pool_available(bool available) {
if (FLAG_enable_embedded_constant_pool) {
constant_pool_available_ = available;
} else {
// Embedded constant pool not supported on this architecture.
UNREACHABLE();
}
}
// The program counter, which points into the buffer above and moves forward.
byte* pc_;
private:
Isolate* isolate_;
int jit_cookie_;
uint64_t enabled_cpu_features_;
bool emit_debug_code_;
bool predictable_code_size_;
bool serializer_enabled_;
// Indicates whether the constant pool can be accessed, which is only possible
// if the pp register points to the current code object's constant pool.
bool constant_pool_available_;
// Constant pool.
friend class FrameAndConstantPoolScope;
friend class ConstantPoolUnavailableScope;
};
// Avoids emitting debug code during the lifetime of this scope object.
class DontEmitDebugCodeScope BASE_EMBEDDED {
public:
explicit DontEmitDebugCodeScope(AssemblerBase* assembler)
: assembler_(assembler), old_value_(assembler->emit_debug_code()) {
assembler_->set_emit_debug_code(false);
}
~DontEmitDebugCodeScope() {
assembler_->set_emit_debug_code(old_value_);
}
private:
AssemblerBase* assembler_;
bool old_value_;
};
// Avoids using instructions that vary in size in unpredictable ways between the
// snapshot and the running VM.
class PredictableCodeSizeScope {
public:
explicit PredictableCodeSizeScope(AssemblerBase* assembler);
PredictableCodeSizeScope(AssemblerBase* assembler, int expected_size);
~PredictableCodeSizeScope();
void ExpectSize(int expected_size) { expected_size_ = expected_size; }
private:
AssemblerBase* assembler_;
int expected_size_;
int start_offset_;
bool old_value_;
};
// Enable a specified feature within a scope.
class CpuFeatureScope BASE_EMBEDDED {
public:
enum CheckPolicy {
kCheckSupported,
kDontCheckSupported,
};
#ifdef DEBUG
CpuFeatureScope(AssemblerBase* assembler, CpuFeature f,
CheckPolicy check = kCheckSupported);
~CpuFeatureScope();
private:
AssemblerBase* assembler_;
uint64_t old_enabled_;
#else
CpuFeatureScope(AssemblerBase* assembler, CpuFeature f,
CheckPolicy check = kCheckSupported) {}
#endif
};
// CpuFeatures keeps track of which features are supported by the target CPU.
// Supported features must be enabled by a CpuFeatureScope before use.
// Example:
// if (assembler->IsSupported(SSE3)) {
// CpuFeatureScope fscope(assembler, SSE3);
// // Generate code containing SSE3 instructions.
// } else {
// // Generate alternative code.
// }
class CpuFeatures : public AllStatic {
public:
static void Probe(bool cross_compile) {
STATIC_ASSERT(NUMBER_OF_CPU_FEATURES <= kBitsPerInt);
if (initialized_) return;
initialized_ = true;
ProbeImpl(cross_compile);
}
static unsigned SupportedFeatures() {
Probe(false);
return supported_;
}
static bool IsSupported(CpuFeature f) {
return (supported_ & (1u << f)) != 0;
}
static inline bool SupportsCrankshaft();
static inline bool SupportsSimd128();
static inline unsigned icache_line_size() {
DCHECK(icache_line_size_ != 0);
return icache_line_size_;
}
static inline unsigned dcache_line_size() {
DCHECK(dcache_line_size_ != 0);
return dcache_line_size_;
}
static void PrintTarget();
static void PrintFeatures();
private:
friend class ExternalReference;
friend class AssemblerBase;
// Flush instruction cache.
static void FlushICache(void* start, size_t size);
// Platform-dependent implementation.
static void ProbeImpl(bool cross_compile);
static unsigned supported_;
static unsigned icache_line_size_;
static unsigned dcache_line_size_;
static bool initialized_;
DISALLOW_COPY_AND_ASSIGN(CpuFeatures);
};
// -----------------------------------------------------------------------------
// Labels represent pc locations; they are typically jump or call targets.
// After declaration, a label can be freely used to denote known or (yet)
// unknown pc location. Assembler::bind() is used to bind a label to the
// current pc. A label can be bound only once.
class Label {
public:
enum Distance {
kNear, kFar
};
INLINE(Label()) {
Unuse();
UnuseNear();
}
INLINE(~Label()) {
DCHECK(!is_linked());
DCHECK(!is_near_linked());
}
INLINE(void Unuse()) { pos_ = 0; }
INLINE(void UnuseNear()) { near_link_pos_ = 0; }
INLINE(bool is_bound() const) { return pos_ < 0; }
INLINE(bool is_unused() const) { return pos_ == 0 && near_link_pos_ == 0; }
INLINE(bool is_linked() const) { return pos_ > 0; }
INLINE(bool is_near_linked() const) { return near_link_pos_ > 0; }
// Returns the position of bound or linked labels. Cannot be used
// for unused labels.
int pos() const;
int near_link_pos() const { return near_link_pos_ - 1; }
private:
// pos_ encodes both the binding state (via its sign)
// and the binding position (via its value) of a label.
//
// pos_ < 0 bound label, pos() returns the jump target position
// pos_ == 0 unused label
// pos_ > 0 linked label, pos() returns the last reference position
int pos_;
// Behaves like |pos_| in the "> 0" case, but for near jumps to this label.
int near_link_pos_;
void bind_to(int pos) {
pos_ = -pos - 1;
DCHECK(is_bound());
}
void link_to(int pos, Distance distance = kFar) {
if (distance == kNear) {
near_link_pos_ = pos + 1;
DCHECK(is_near_linked());
} else {
pos_ = pos + 1;
DCHECK(is_linked());
}
}
friend class Assembler;
friend class Displacement;
friend class RegExpMacroAssemblerIrregexp;
#if V8_TARGET_ARCH_ARM64
// On ARM64, the Assembler keeps track of pointers to Labels to resolve
// branches to distant targets. Copying labels would confuse the Assembler.
DISALLOW_COPY_AND_ASSIGN(Label); // NOLINT
#endif
};
enum SaveFPRegsMode { kDontSaveFPRegs, kSaveFPRegs };
enum ArgvMode { kArgvOnStack, kArgvInRegister };
// Specifies whether to perform icache flush operations on RelocInfo updates.
// If FLUSH_ICACHE_IF_NEEDED, the icache will always be flushed if an
// instruction was modified. If SKIP_ICACHE_FLUSH the flush will always be
// skipped (only use this if you will flush the icache manually before it is
// executed).
enum ICacheFlushMode { FLUSH_ICACHE_IF_NEEDED, SKIP_ICACHE_FLUSH };
// -----------------------------------------------------------------------------
// Relocation information
// Relocation information consists of the address (pc) of the datum
// to which the relocation information applies, the relocation mode
// (rmode), and an optional data field. The relocation mode may be
// "descriptive" and not indicate a need for relocation, but simply
// describe a property of the datum. Such rmodes are useful for GC
// and nice disassembly output.
class RelocInfo {
public:
// This string is used to add padding comments to the reloc info in cases
// where we are not sure to have enough space for patching in during
// lazy deoptimization. This is the case if we have indirect calls for which
// we do not normally record relocation info.
static const char* const kFillerCommentString;
// The minimum size of a comment is equal to two bytes for the extra tagged
// pc and kPointerSize for the actual pointer to the comment.
static const int kMinRelocCommentSize = 2 + kPointerSize;
// The maximum size for a call instruction including pc-jump.
static const int kMaxCallSize = 6;
// The maximum pc delta that will use the short encoding.
static const int kMaxSmallPCDelta;
enum Mode {
// Please note the order is important (see IsCodeTarget, IsGCRelocMode).
CODE_TARGET, // Code target which is not any of the above.
CODE_TARGET_WITH_ID,
DEBUGGER_STATEMENT, // Code target for the debugger statement.
EMBEDDED_OBJECT,
// To relocate pointers into the wasm memory embedded in wasm code
WASM_MEMORY_REFERENCE,
WASM_GLOBAL_REFERENCE,
WASM_MEMORY_SIZE_REFERENCE,
CELL,
// Everything after runtime_entry (inclusive) is not GC'ed.
RUNTIME_ENTRY,
COMMENT,
// Additional code inserted for debug break slot.
DEBUG_BREAK_SLOT_AT_POSITION,
DEBUG_BREAK_SLOT_AT_RETURN,
DEBUG_BREAK_SLOT_AT_CALL,
DEBUG_BREAK_SLOT_AT_TAIL_CALL,
EXTERNAL_REFERENCE, // The address of an external C++ function.
INTERNAL_REFERENCE, // An address inside the same function.
// Encoded internal reference, used only on MIPS, MIPS64 and PPC.
INTERNAL_REFERENCE_ENCODED,
// Continuation points for a generator yield.
GENERATOR_CONTINUATION,
// Marks constant and veneer pools. Only used on ARM and ARM64.
// They use a custom noncompact encoding.
CONST_POOL,
VENEER_POOL,
DEOPT_POSITION, // Deoptimization source position.
DEOPT_REASON, // Deoptimization reason index.
DEOPT_ID, // Deoptimization inlining id.
// This is not an actual reloc mode, but used to encode a long pc jump that
// cannot be encoded as part of another record.
PC_JUMP,
// Pseudo-types
NUMBER_OF_MODES,
NONE32, // never recorded 32-bit value
NONE64, // never recorded 64-bit value
CODE_AGE_SEQUENCE, // Not stored in RelocInfo array, used explictly by
// code aging.
FIRST_REAL_RELOC_MODE = CODE_TARGET,
LAST_REAL_RELOC_MODE = VENEER_POOL,
LAST_CODE_ENUM = DEBUGGER_STATEMENT,
LAST_GCED_ENUM = WASM_MEMORY_SIZE_REFERENCE,
FIRST_SHAREABLE_RELOC_MODE = CELL,
};
STATIC_ASSERT(NUMBER_OF_MODES <= kBitsPerInt);
explicit RelocInfo(Isolate* isolate) : isolate_(isolate) {
DCHECK_NOT_NULL(isolate);
}
RelocInfo(Isolate* isolate, byte* pc, Mode rmode, intptr_t data, Code* host)
: isolate_(isolate), pc_(pc), rmode_(rmode), data_(data), host_(host) {
DCHECK_NOT_NULL(isolate);
}
static inline bool IsRealRelocMode(Mode mode) {
return mode >= FIRST_REAL_RELOC_MODE && mode <= LAST_REAL_RELOC_MODE;
}
static inline bool IsCodeTarget(Mode mode) {
return mode <= LAST_CODE_ENUM;
}
static inline bool IsEmbeddedObject(Mode mode) {
return mode == EMBEDDED_OBJECT;
}
static inline bool IsCell(Mode mode) { return mode == CELL; }
static inline bool IsRuntimeEntry(Mode mode) {
return mode == RUNTIME_ENTRY;
}
// Is the relocation mode affected by GC?
static inline bool IsGCRelocMode(Mode mode) {
return mode <= LAST_GCED_ENUM;
}
static inline bool IsComment(Mode mode) {
return mode == COMMENT;
}
static inline bool IsConstPool(Mode mode) {
return mode == CONST_POOL;
}
static inline bool IsVeneerPool(Mode mode) {
return mode == VENEER_POOL;
}
static inline bool IsDeoptPosition(Mode mode) {
return mode == DEOPT_POSITION;
}
static inline bool IsDeoptReason(Mode mode) {
return mode == DEOPT_REASON;
}
static inline bool IsDeoptId(Mode mode) {
return mode == DEOPT_ID;
}
static inline bool IsExternalReference(Mode mode) {
return mode == EXTERNAL_REFERENCE;
}
static inline bool IsInternalReference(Mode mode) {
return mode == INTERNAL_REFERENCE;
}
static inline bool IsInternalReferenceEncoded(Mode mode) {
return mode == INTERNAL_REFERENCE_ENCODED;
}
static inline bool IsDebugBreakSlot(Mode mode) {
return IsDebugBreakSlotAtPosition(mode) || IsDebugBreakSlotAtReturn(mode) ||
IsDebugBreakSlotAtCall(mode) || IsDebugBreakSlotAtTailCall(mode);
}
static inline bool IsDebugBreakSlotAtPosition(Mode mode) {
return mode == DEBUG_BREAK_SLOT_AT_POSITION;
}
static inline bool IsDebugBreakSlotAtReturn(Mode mode) {
return mode == DEBUG_BREAK_SLOT_AT_RETURN;
}
static inline bool IsDebugBreakSlotAtCall(Mode mode) {
return mode == DEBUG_BREAK_SLOT_AT_CALL;
}
static inline bool IsDebugBreakSlotAtTailCall(Mode mode) {
return mode == DEBUG_BREAK_SLOT_AT_TAIL_CALL;
}
static inline bool IsDebuggerStatement(Mode mode) {
return mode == DEBUGGER_STATEMENT;
}
static inline bool IsNone(Mode mode) {
return mode == NONE32 || mode == NONE64;
}
static inline bool IsCodeAgeSequence(Mode mode) {
return mode == CODE_AGE_SEQUENCE;
}
static inline bool IsGeneratorContinuation(Mode mode) {
return mode == GENERATOR_CONTINUATION;
}
static inline bool IsWasmMemoryReference(Mode mode) {
return mode == WASM_MEMORY_REFERENCE;
}
static inline bool IsWasmMemorySizeReference(Mode mode) {
return mode == WASM_MEMORY_SIZE_REFERENCE;
}
static inline bool IsWasmGlobalReference(Mode mode) {
return mode == WASM_GLOBAL_REFERENCE;
}
static inline int ModeMask(Mode mode) { return 1 << mode; }
// Accessors
Isolate* isolate() const { return isolate_; }
byte* pc() const { return pc_; }
void set_pc(byte* pc) { pc_ = pc; }
Mode rmode() const { return rmode_; }
intptr_t data() const { return data_; }
Code* host() const { return host_; }
void set_host(Code* host) { host_ = host; }
// Apply a relocation by delta bytes. When the code object is moved, PC
// relative addresses have to be updated as well as absolute addresses
// inside the code (internal references).
// Do not forget to flush the icache afterwards!
INLINE(void apply(intptr_t delta));
// Is the pointer this relocation info refers to coded like a plain pointer
// or is it strange in some way (e.g. relative or patched into a series of
// instructions).
bool IsCodedSpecially();
// If true, the pointer this relocation info refers to is an entry in the
// constant pool, otherwise the pointer is embedded in the instruction stream.
bool IsInConstantPool();
Address wasm_memory_reference();
Address wasm_global_reference();
uint32_t wasm_memory_size_reference();
void update_wasm_memory_reference(
Address old_base, Address new_base, uint32_t old_size, uint32_t new_size,
ICacheFlushMode icache_flush_mode = FLUSH_ICACHE_IF_NEEDED);
void update_wasm_global_reference(
Address old_base, Address new_base,
ICacheFlushMode icache_flush_mode = FLUSH_ICACHE_IF_NEEDED);
void set_target_address(
Address target,
WriteBarrierMode write_barrier_mode = UPDATE_WRITE_BARRIER,
ICacheFlushMode icache_flush_mode = FLUSH_ICACHE_IF_NEEDED);
// this relocation applies to;
// can only be called if IsCodeTarget(rmode_) || IsRuntimeEntry(rmode_)
INLINE(Address target_address());
INLINE(Object* target_object());
INLINE(Handle<Object> target_object_handle(Assembler* origin));
INLINE(void set_target_object(
Object* target,
WriteBarrierMode write_barrier_mode = UPDATE_WRITE_BARRIER,
ICacheFlushMode icache_flush_mode = FLUSH_ICACHE_IF_NEEDED));
INLINE(Address target_runtime_entry(Assembler* origin));
INLINE(void set_target_runtime_entry(
Address target,
WriteBarrierMode write_barrier_mode = UPDATE_WRITE_BARRIER,
ICacheFlushMode icache_flush_mode = FLUSH_ICACHE_IF_NEEDED));
INLINE(Cell* target_cell());
INLINE(Handle<Cell> target_cell_handle());
INLINE(void set_target_cell(
Cell* cell, WriteBarrierMode write_barrier_mode = UPDATE_WRITE_BARRIER,
ICacheFlushMode icache_flush_mode = FLUSH_ICACHE_IF_NEEDED));
INLINE(Handle<Object> code_age_stub_handle(Assembler* origin));
INLINE(Code* code_age_stub());
INLINE(void set_code_age_stub(
Code* stub, ICacheFlushMode icache_flush_mode = FLUSH_ICACHE_IF_NEEDED));
// Returns the address of the constant pool entry where the target address
// is held. This should only be called if IsInConstantPool returns true.
INLINE(Address constant_pool_entry_address());
// Read the address of the word containing the target_address in an
// instruction stream. What this means exactly is architecture-independent.
// The only architecture-independent user of this function is the serializer.
// The serializer uses it to find out how many raw bytes of instruction to
// output before the next target. Architecture-independent code shouldn't
// dereference the pointer it gets back from this.
INLINE(Address target_address_address());
// This indicates how much space a target takes up when deserializing a code
// stream. For most architectures this is just the size of a pointer. For
// an instruction like movw/movt where the target bits are mixed into the
// instruction bits the size of the target will be zero, indicating that the
// serializer should not step forwards in memory after a target is resolved
// and written. In this case the target_address_address function above
// should return the end of the instructions to be patched, allowing the
// deserializer to deserialize the instructions as raw bytes and put them in
// place, ready to be patched with the target.
INLINE(int target_address_size());
// Read the reference in the instruction this relocation
// applies to; can only be called if rmode_ is EXTERNAL_REFERENCE.
INLINE(Address target_external_reference());
// Read the reference in the instruction this relocation
// applies to; can only be called if rmode_ is INTERNAL_REFERENCE.
INLINE(Address target_internal_reference());
// Return the reference address this relocation applies to;
// can only be called if rmode_ is INTERNAL_REFERENCE.
INLINE(Address target_internal_reference_address());
// Read/modify the address of a call instruction. This is used to relocate
// the break points where straight-line code is patched with a call
// instruction.
INLINE(Address debug_call_address());
INLINE(void set_debug_call_address(Address target));
// Wipe out a relocation to a fixed value, used for making snapshots
// reproducible.
INLINE(void WipeOut());
template<typename StaticVisitor> inline void Visit(Heap* heap);
template <typename ObjectVisitor>
inline void Visit(Isolate* isolate, ObjectVisitor* v);
// Check whether this debug break slot has been patched with a call to the
// debugger.
bool IsPatchedDebugBreakSlotSequence();
#ifdef DEBUG
// Check whether the given code contains relocation information that
// either is position-relative or movable by the garbage collector.
static bool RequiresRelocation(const CodeDesc& desc);
#endif
#ifdef ENABLE_DISASSEMBLER
// Printing
static const char* RelocModeName(Mode rmode);
void Print(Isolate* isolate, std::ostream& os); // NOLINT
#endif // ENABLE_DISASSEMBLER
#ifdef VERIFY_HEAP
void Verify(Isolate* isolate);
#endif
static const int kCodeTargetMask = (1 << (LAST_CODE_ENUM + 1)) - 1;
static const int kDataMask = (1 << CODE_TARGET_WITH_ID) | (1 << COMMENT);
static const int kDebugBreakSlotMask = 1 << DEBUG_BREAK_SLOT_AT_POSITION |
1 << DEBUG_BREAK_SLOT_AT_RETURN |
1 << DEBUG_BREAK_SLOT_AT_CALL;
static const int kApplyMask; // Modes affected by apply. Depends on arch.
private:
void unchecked_update_wasm_memory_reference(Address address,
ICacheFlushMode flush_mode);
void unchecked_update_wasm_memory_size(uint32_t size,
ICacheFlushMode flush_mode);
Isolate* isolate_;
// On ARM, note that pc_ is the address of the constant pool entry
// to be relocated and not the address of the instruction
// referencing the constant pool entry (except when rmode_ ==
// comment).
byte* pc_;
Mode rmode_;
intptr_t data_;
Code* host_;
friend class RelocIterator;
};
// RelocInfoWriter serializes a stream of relocation info. It writes towards
// lower addresses.
class RelocInfoWriter BASE_EMBEDDED {
public:
RelocInfoWriter() : pos_(NULL), last_pc_(NULL), last_id_(0) {}
RelocInfoWriter(byte* pos, byte* pc) : pos_(pos), last_pc_(pc), last_id_(0) {}
byte* pos() const { return pos_; }
byte* last_pc() const { return last_pc_; }
void Write(const RelocInfo* rinfo);
// Update the state of the stream after reloc info buffer
// and/or code is moved while the stream is active.
void Reposition(byte* pos, byte* pc) {
pos_ = pos;
last_pc_ = pc;
}
// Max size (bytes) of a written RelocInfo. Longest encoding is
// ExtraTag, VariableLengthPCJump, ExtraTag, pc_delta, data_delta.
// On ia32 and arm this is 1 + 4 + 1 + 1 + 4 = 11.
// On x64 this is 1 + 4 + 1 + 1 + 8 == 15;
// Here we use the maximum of the two.
static const int kMaxSize = 15;
private:
inline uint32_t WriteLongPCJump(uint32_t pc_delta);
inline void WriteShortTaggedPC(uint32_t pc_delta, int tag);
inline void WriteShortTaggedData(intptr_t data_delta, int tag);
inline void WriteMode(RelocInfo::Mode rmode);
inline void WriteModeAndPC(uint32_t pc_delta, RelocInfo::Mode rmode);
inline void WriteIntData(int data_delta);
inline void WriteData(intptr_t data_delta);
byte* pos_;
byte* last_pc_;
int last_id_;
RelocInfo::Mode last_mode_;
DISALLOW_COPY_AND_ASSIGN(RelocInfoWriter);
};
// A RelocIterator iterates over relocation information.
// Typical use:
//
// for (RelocIterator it(code); !it.done(); it.next()) {
// // do something with it.rinfo() here
// }
//
// A mask can be specified to skip unwanted modes.
class RelocIterator: public Malloced {
public:
// Create a new iterator positioned at
// the beginning of the reloc info.
// Relocation information with mode k is included in the
// iteration iff bit k of mode_mask is set.
explicit RelocIterator(Code* code, int mode_mask = -1);
explicit RelocIterator(const CodeDesc& desc, int mode_mask = -1);
// Iteration
bool done() const { return done_; }
void next();
// Return pointer valid until next next().
RelocInfo* rinfo() {
DCHECK(!done());
return &rinfo_;
}
private:
// Advance* moves the position before/after reading.
// *Read* reads from current byte(s) into rinfo_.
// *Get* just reads and returns info on current byte.
void Advance(int bytes = 1) { pos_ -= bytes; }
int AdvanceGetTag();
RelocInfo::Mode GetMode();
void AdvanceReadLongPCJump();
int GetShortDataTypeTag();
void ReadShortTaggedPC();
void ReadShortTaggedId();
void ReadShortTaggedData();
void AdvanceReadPC();
void AdvanceReadId();
void AdvanceReadInt();
void AdvanceReadData();
// If the given mode is wanted, set it in rinfo_ and return true.
// Else return false. Used for efficiently skipping unwanted modes.
bool SetMode(RelocInfo::Mode mode) {
return (mode_mask_ & (1 << mode)) ? (rinfo_.rmode_ = mode, true) : false;
}
byte* pos_;
byte* end_;
byte* code_age_sequence_;
RelocInfo rinfo_;
bool done_;
int mode_mask_;
int last_id_;
DISALLOW_COPY_AND_ASSIGN(RelocIterator);
};
//------------------------------------------------------------------------------
// External function
//----------------------------------------------------------------------------
class SCTableReference;
class Debug_Address;
// An ExternalReference represents a C++ address used in the generated
// code. All references to C++ functions and variables must be encapsulated in
// an ExternalReference instance. This is done in order to track the origin of
// all external references in the code so that they can be bound to the correct
// addresses when deserializing a heap.
class ExternalReference BASE_EMBEDDED {
public:
// Used in the simulator to support different native api calls.
enum Type {
// Builtin call.
// Object* f(v8::internal::Arguments).
BUILTIN_CALL, // default
// Builtin call returning object pair.
// ObjectPair f(v8::internal::Arguments).
BUILTIN_CALL_PAIR,
// Builtin call that returns .
// ObjectTriple f(v8::internal::Arguments).
BUILTIN_CALL_TRIPLE,
// Builtin that takes float arguments and returns an int.
// int f(double, double).
BUILTIN_COMPARE_CALL,
// Builtin call that returns floating point.
// double f(double, double).
BUILTIN_FP_FP_CALL,
// Builtin call that returns floating point.
// double f(double).
BUILTIN_FP_CALL,
// Builtin call that returns floating point.
// double f(double, int).
BUILTIN_FP_INT_CALL,
// Direct call to API function callback.
// void f(v8::FunctionCallbackInfo&)
DIRECT_API_CALL,
// Call to function callback via InvokeFunctionCallback.
// void f(v8::FunctionCallbackInfo&, v8::FunctionCallback)
PROFILING_API_CALL,
// Direct call to accessor getter callback.
// void f(Local<Name> property, PropertyCallbackInfo& info)
DIRECT_GETTER_CALL,
// Call to accessor getter callback via InvokeAccessorGetterCallback.
// void f(Local<Name> property, PropertyCallbackInfo& info,
// AccessorNameGetterCallback callback)
PROFILING_GETTER_CALL
};
static void SetUp();
typedef void* ExternalReferenceRedirector(Isolate* isolate, void* original,
Type type);
ExternalReference() : address_(NULL) {}
ExternalReference(Address address, Isolate* isolate);
ExternalReference(ApiFunction* ptr, Type type, Isolate* isolate);
ExternalReference(Builtins::Name name, Isolate* isolate);
ExternalReference(Runtime::FunctionId id, Isolate* isolate);
ExternalReference(const Runtime::Function* f, Isolate* isolate);
explicit ExternalReference(StatsCounter* counter);
ExternalReference(Isolate::AddressId id, Isolate* isolate);
explicit ExternalReference(const SCTableReference& table_ref);
// Isolate as an external reference.
static ExternalReference isolate_address(Isolate* isolate);
// One-of-a-kind references. These references are not part of a general
// pattern. This means that they have to be added to the
// ExternalReferenceTable in serialize.cc manually.
static ExternalReference interpreter_dispatch_table_address(Isolate* isolate);
static ExternalReference interpreter_dispatch_counters(Isolate* isolate);
static ExternalReference incremental_marking_record_write_function(
Isolate* isolate);
static ExternalReference incremental_marking_record_write_code_entry_function(
Isolate* isolate);
static ExternalReference store_buffer_overflow_function(
Isolate* isolate);
static ExternalReference delete_handle_scope_extensions(Isolate* isolate);
static ExternalReference get_date_field_function(Isolate* isolate);
static ExternalReference date_cache_stamp(Isolate* isolate);
static ExternalReference get_make_code_young_function(Isolate* isolate);
static ExternalReference get_mark_code_as_executed_function(Isolate* isolate);
// Deoptimization support.
static ExternalReference new_deoptimizer_function(Isolate* isolate);
static ExternalReference compute_output_frames_function(Isolate* isolate);
static ExternalReference wasm_f32_trunc(Isolate* isolate);
static ExternalReference wasm_f32_floor(Isolate* isolate);
static ExternalReference wasm_f32_ceil(Isolate* isolate);
static ExternalReference wasm_f32_nearest_int(Isolate* isolate);
static ExternalReference wasm_f64_trunc(Isolate* isolate);
static ExternalReference wasm_f64_floor(Isolate* isolate);
static ExternalReference wasm_f64_ceil(Isolate* isolate);
static ExternalReference wasm_f64_nearest_int(Isolate* isolate);
static ExternalReference wasm_int64_to_float32(Isolate* isolate);
static ExternalReference wasm_uint64_to_float32(Isolate* isolate);
static ExternalReference wasm_int64_to_float64(Isolate* isolate);
static ExternalReference wasm_uint64_to_float64(Isolate* isolate);
static ExternalReference wasm_float32_to_int64(Isolate* isolate);
static ExternalReference wasm_float32_to_uint64(Isolate* isolate);
static ExternalReference wasm_float64_to_int64(Isolate* isolate);
static ExternalReference wasm_float64_to_uint64(Isolate* isolate);
static ExternalReference wasm_int64_div(Isolate* isolate);
static ExternalReference wasm_int64_mod(Isolate* isolate);
static ExternalReference wasm_uint64_div(Isolate* isolate);
static ExternalReference wasm_uint64_mod(Isolate* isolate);
static ExternalReference wasm_word32_ctz(Isolate* isolate);
static ExternalReference wasm_word64_ctz(Isolate* isolate);
static ExternalReference wasm_word32_popcnt(Isolate* isolate);
static ExternalReference wasm_word64_popcnt(Isolate* isolate);
static ExternalReference wasm_float64_pow(Isolate* isolate);
static ExternalReference f64_acos_wrapper_function(Isolate* isolate);
static ExternalReference f64_asin_wrapper_function(Isolate* isolate);
static ExternalReference f64_mod_wrapper_function(Isolate* isolate);
// Log support.
static ExternalReference log_enter_external_function(Isolate* isolate);
static ExternalReference log_leave_external_function(Isolate* isolate);
// Static variable Heap::roots_array_start()
static ExternalReference roots_array_start(Isolate* isolate);
// Static variable Heap::allocation_sites_list_address()
static ExternalReference allocation_sites_list_address(Isolate* isolate);
// Static variable StackGuard::address_of_jslimit()
V8_EXPORT_PRIVATE static ExternalReference address_of_stack_limit(
Isolate* isolate);
// Static variable StackGuard::address_of_real_jslimit()
static ExternalReference address_of_real_stack_limit(Isolate* isolate);
// Static variable RegExpStack::limit_address()
static ExternalReference address_of_regexp_stack_limit(Isolate* isolate);
// Static variables for RegExp.
static ExternalReference address_of_static_offsets_vector(Isolate* isolate);
static ExternalReference address_of_regexp_stack_memory_address(
Isolate* isolate);
static ExternalReference address_of_regexp_stack_memory_size(
Isolate* isolate);
// Write barrier.
static ExternalReference store_buffer_top(Isolate* isolate);
// Used for fast allocation in generated code.
static ExternalReference new_space_allocation_top_address(Isolate* isolate);
static ExternalReference new_space_allocation_limit_address(Isolate* isolate);
static ExternalReference old_space_allocation_top_address(Isolate* isolate);
static ExternalReference old_space_allocation_limit_address(Isolate* isolate);
static ExternalReference mod_two_doubles_operation(Isolate* isolate);
static ExternalReference power_double_double_function(Isolate* isolate);
static ExternalReference handle_scope_next_address(Isolate* isolate);
static ExternalReference handle_scope_limit_address(Isolate* isolate);
static ExternalReference handle_scope_level_address(Isolate* isolate);
static ExternalReference scheduled_exception_address(Isolate* isolate);
static ExternalReference address_of_pending_message_obj(Isolate* isolate);
// Static variables containing common double constants.
static ExternalReference address_of_min_int();
static ExternalReference address_of_one_half();
static ExternalReference address_of_minus_one_half();
static ExternalReference address_of_negative_infinity();
static ExternalReference address_of_the_hole_nan();
static ExternalReference address_of_uint32_bias();
// Static variables containing simd constants.
static ExternalReference address_of_float_abs_constant();
static ExternalReference address_of_float_neg_constant();
static ExternalReference address_of_double_abs_constant();
static ExternalReference address_of_double_neg_constant();
// IEEE 754 functions.
static ExternalReference ieee754_acos_function(Isolate* isolate);
static ExternalReference ieee754_acosh_function(Isolate* isolate);
static ExternalReference ieee754_asin_function(Isolate* isolate);
static ExternalReference ieee754_asinh_function(Isolate* isolate);
static ExternalReference ieee754_atan_function(Isolate* isolate);
static ExternalReference ieee754_atanh_function(Isolate* isolate);
static ExternalReference ieee754_atan2_function(Isolate* isolate);
static ExternalReference ieee754_cbrt_function(Isolate* isolate);
static ExternalReference ieee754_cos_function(Isolate* isolate);
static ExternalReference ieee754_cosh_function(Isolate* isolate);
static ExternalReference ieee754_exp_function(Isolate* isolate);
static ExternalReference ieee754_expm1_function(Isolate* isolate);
static ExternalReference ieee754_log_function(Isolate* isolate);
static ExternalReference ieee754_log1p_function(Isolate* isolate);
static ExternalReference ieee754_log10_function(Isolate* isolate);
static ExternalReference ieee754_log2_function(Isolate* isolate);
static ExternalReference ieee754_sin_function(Isolate* isolate);
static ExternalReference ieee754_sinh_function(Isolate* isolate);
static ExternalReference ieee754_tan_function(Isolate* isolate);
static ExternalReference ieee754_tanh_function(Isolate* isolate);
static ExternalReference page_flags(Page* page);
static ExternalReference ForDeoptEntry(Address entry);
static ExternalReference cpu_features();
static ExternalReference is_tail_call_elimination_enabled_address(
Isolate* isolate);
static ExternalReference debug_is_active_address(Isolate* isolate);
static ExternalReference debug_after_break_target_address(Isolate* isolate);
static ExternalReference is_profiling_address(Isolate* isolate);
static ExternalReference invoke_function_callback(Isolate* isolate);
static ExternalReference invoke_accessor_getter_callback(Isolate* isolate);
V8_EXPORT_PRIVATE static ExternalReference runtime_function_table_address(
Isolate* isolate);
Address address() const { return reinterpret_cast<Address>(address_); }
// Used to read out the last step action of the debugger.
static ExternalReference debug_last_step_action_address(Isolate* isolate);
// Used to check for suspended generator, used for stepping across await call.
static ExternalReference debug_suspended_generator_address(Isolate* isolate);
#ifndef V8_INTERPRETED_REGEXP
// C functions called from RegExp generated code.
// Function NativeRegExpMacroAssembler::CaseInsensitiveCompareUC16()
static ExternalReference re_case_insensitive_compare_uc16(Isolate* isolate);
// Function RegExpMacroAssembler*::CheckStackGuardState()
static ExternalReference re_check_stack_guard_state(Isolate* isolate);
// Function NativeRegExpMacroAssembler::GrowStack()
static ExternalReference re_grow_stack(Isolate* isolate);
// byte NativeRegExpMacroAssembler::word_character_bitmap
static ExternalReference re_word_character_map();
#endif
// This lets you register a function that rewrites all external references.
// Used by the ARM simulator to catch calls to external references.
static void set_redirector(Isolate* isolate,
ExternalReferenceRedirector* redirector) {
// We can't stack them.
DCHECK(isolate->external_reference_redirector() == NULL);
isolate->set_external_reference_redirector(
reinterpret_cast<ExternalReferenceRedirectorPointer*>(redirector));
}
static ExternalReference stress_deopt_count(Isolate* isolate);
static ExternalReference fixed_typed_array_base_data_offset();
private:
explicit ExternalReference(void* address)
: address_(address) {}
static void* Redirect(Isolate* isolate,
Address address_arg,
Type type = ExternalReference::BUILTIN_CALL) {
ExternalReferenceRedirector* redirector =
reinterpret_cast<ExternalReferenceRedirector*>(
isolate->external_reference_redirector());
void* address = reinterpret_cast<void*>(address_arg);
void* answer =
(redirector == NULL) ? address : (*redirector)(isolate, address, type);
return answer;
}
void* address_;
};
V8_EXPORT_PRIVATE bool operator==(ExternalReference, ExternalReference);
bool operator!=(ExternalReference, ExternalReference);
size_t hash_value(ExternalReference);
V8_EXPORT_PRIVATE std::ostream& operator<<(std::ostream&, ExternalReference);
// -----------------------------------------------------------------------------
// Utility functions
inline int NumberOfBitsSet(uint32_t x) {
unsigned int num_bits_set;
for (num_bits_set = 0; x; x >>= 1) {
num_bits_set += x & 1;
}
return num_bits_set;
}
// Computes pow(x, y) with the special cases in the spec for Math.pow.
double power_helper(Isolate* isolate, double x, double y);
double power_double_int(double x, int y);
double power_double_double(double x, double y);
// Helper class for generating code or data associated with the code
// right after a call instruction. As an example this can be used to
// generate safepoint data after calls for crankshaft.
class CallWrapper {
public:
CallWrapper() { }
virtual ~CallWrapper() { }
// Called just before emitting a call. Argument is the size of the generated
// call code.
virtual void BeforeCall(int call_size) const = 0;
// Called just after emitting a call, i.e., at the return site for the call.
virtual void AfterCall() const = 0;
// Return whether call needs to check for debug stepping.
virtual bool NeedsDebugStepCheck() const { return false; }
};
class NullCallWrapper : public CallWrapper {
public:
NullCallWrapper() { }
virtual ~NullCallWrapper() { }
virtual void BeforeCall(int call_size) const { }
virtual void AfterCall() const { }
};
class CheckDebugStepCallWrapper : public CallWrapper {
public:
CheckDebugStepCallWrapper() {}
virtual ~CheckDebugStepCallWrapper() {}
virtual void BeforeCall(int call_size) const {}
virtual void AfterCall() const {}
virtual bool NeedsDebugStepCheck() const { return true; }
};
// -----------------------------------------------------------------------------
// Constant pool support
class ConstantPoolEntry {
public:
ConstantPoolEntry() {}
ConstantPoolEntry(int position, intptr_t value, bool sharing_ok)
: position_(position),
merged_index_(sharing_ok ? SHARING_ALLOWED : SHARING_PROHIBITED),
value_(value) {}
ConstantPoolEntry(int position, double value)
: position_(position), merged_index_(SHARING_ALLOWED), value64_(value) {}
int position() const { return position_; }
bool sharing_ok() const { return merged_index_ != SHARING_PROHIBITED; }
bool is_merged() const { return merged_index_ >= 0; }
int merged_index(void) const {
DCHECK(is_merged());
return merged_index_;
}
void set_merged_index(int index) {
merged_index_ = index;
DCHECK(is_merged());
}
int offset(void) const {
DCHECK(merged_index_ >= 0);
return merged_index_;
}
void set_offset(int offset) {
DCHECK(offset >= 0);
merged_index_ = offset;
}
intptr_t value() const { return value_; }
uint64_t value64() const { return bit_cast<uint64_t>(value64_); }
enum Type { INTPTR, DOUBLE, NUMBER_OF_TYPES };
static int size(Type type) {
return (type == INTPTR) ? kPointerSize : kDoubleSize;
}
enum Access { REGULAR, OVERFLOWED };
private:
int position_;
int merged_index_;
union {
intptr_t value_;
double value64_;
};
enum { SHARING_PROHIBITED = -2, SHARING_ALLOWED = -1 };
};
// -----------------------------------------------------------------------------
// Embedded constant pool support
class ConstantPoolBuilder BASE_EMBEDDED {
public:
ConstantPoolBuilder(int ptr_reach_bits, int double_reach_bits);
// Add pointer-sized constant to the embedded constant pool
ConstantPoolEntry::Access AddEntry(int position, intptr_t value,
bool sharing_ok) {
ConstantPoolEntry entry(position, value, sharing_ok);
return AddEntry(entry, ConstantPoolEntry::INTPTR);
}
// Add double constant to the embedded constant pool
ConstantPoolEntry::Access AddEntry(int position, double value) {
ConstantPoolEntry entry(position, value);
return AddEntry(entry, ConstantPoolEntry::DOUBLE);
}
// Previews the access type required for the next new entry to be added.
ConstantPoolEntry::Access NextAccess(ConstantPoolEntry::Type type) const;
bool IsEmpty() {
return info_[ConstantPoolEntry::INTPTR].entries.empty() &&
info_[ConstantPoolEntry::INTPTR].shared_entries.empty() &&
info_[ConstantPoolEntry::DOUBLE].entries.empty() &&
info_[ConstantPoolEntry::DOUBLE].shared_entries.empty();
}
// Emit the constant pool. Invoke only after all entries have been
// added and all instructions have been emitted.
// Returns position of the emitted pool (zero implies no constant pool).
int Emit(Assembler* assm);
// Returns the label associated with the start of the constant pool.
// Linking to this label in the function prologue may provide an
// efficient means of constant pool pointer register initialization
// on some architectures.
inline Label* EmittedPosition() { return &emitted_label_; }
private:
ConstantPoolEntry::Access AddEntry(ConstantPoolEntry& entry,
ConstantPoolEntry::Type type);
void EmitSharedEntries(Assembler* assm, ConstantPoolEntry::Type type);
void EmitGroup(Assembler* assm, ConstantPoolEntry::Access access,
ConstantPoolEntry::Type type);
struct PerTypeEntryInfo {
PerTypeEntryInfo() : regular_count(0), overflow_start(-1) {}
bool overflow() const {
return (overflow_start >= 0 &&
overflow_start < static_cast<int>(entries.size()));
}
int regular_reach_bits;
int regular_count;
int overflow_start;
std::vector<ConstantPoolEntry> entries;
std::vector<ConstantPoolEntry> shared_entries;
};
Label emitted_label_; // Records pc_offset of emitted pool
PerTypeEntryInfo info_[ConstantPoolEntry::NUMBER_OF_TYPES];
};
} // namespace internal
} // namespace v8
#endif // V8_ASSEMBLER_H_