| // Copyright 2012 the V8 project authors. 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. |
| // * Redistributions 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 Google Inc. nor the names of its |
| // 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. |
| |
| #ifndef V8_UTILS_H_ |
| #define V8_UTILS_H_ |
| |
| #include <stdlib.h> |
| #include <string.h> |
| #include <climits> |
| |
| #include "globals.h" |
| #include "checks.h" |
| #include "allocation.h" |
| |
| namespace v8 { |
| namespace internal { |
| |
| // ---------------------------------------------------------------------------- |
| // General helper functions |
| |
| #define IS_POWER_OF_TWO(x) (((x) & ((x) - 1)) == 0) |
| |
| // Returns true iff x is a power of 2 (or zero). Cannot be used with the |
| // maximally negative value of the type T (the -1 overflows). |
| template <typename T> |
| inline bool IsPowerOf2(T x) { |
| return IS_POWER_OF_TWO(x); |
| } |
| |
| |
| // X must be a power of 2. Returns the number of trailing zeros. |
| inline int WhichPowerOf2(uint32_t x) { |
| ASSERT(IsPowerOf2(x)); |
| ASSERT(x != 0); |
| int bits = 0; |
| #ifdef DEBUG |
| int original_x = x; |
| #endif |
| if (x >= 0x10000) { |
| bits += 16; |
| x >>= 16; |
| } |
| if (x >= 0x100) { |
| bits += 8; |
| x >>= 8; |
| } |
| if (x >= 0x10) { |
| bits += 4; |
| x >>= 4; |
| } |
| switch (x) { |
| default: UNREACHABLE(); |
| case 8: bits++; // Fall through. |
| case 4: bits++; // Fall through. |
| case 2: bits++; // Fall through. |
| case 1: break; |
| } |
| ASSERT_EQ(1 << bits, original_x); |
| return bits; |
| return 0; |
| } |
| |
| |
| // Magic numbers for integer division. |
| // These are kind of 2's complement reciprocal of the divisors. |
| // Details and proofs can be found in: |
| // - Hacker's Delight, Henry S. Warren, Jr. |
| // - The PowerPC Compiler Writer’s Guide |
| // and probably many others. |
| // See details in the implementation of the algorithm in |
| // lithium-codegen-arm.cc : LCodeGen::TryEmitSignedIntegerDivisionByConstant(). |
| struct DivMagicNumbers { |
| unsigned M; |
| unsigned s; |
| }; |
| |
| const DivMagicNumbers InvalidDivMagicNumber= {0, 0}; |
| const DivMagicNumbers DivMagicNumberFor3 = {0x55555556, 0}; |
| const DivMagicNumbers DivMagicNumberFor5 = {0x66666667, 1}; |
| const DivMagicNumbers DivMagicNumberFor7 = {0x92492493, 2}; |
| const DivMagicNumbers DivMagicNumberFor9 = {0x38e38e39, 1}; |
| const DivMagicNumbers DivMagicNumberFor11 = {0x2e8ba2e9, 1}; |
| const DivMagicNumbers DivMagicNumberFor25 = {0x51eb851f, 3}; |
| const DivMagicNumbers DivMagicNumberFor125 = {0x10624dd3, 3}; |
| const DivMagicNumbers DivMagicNumberFor625 = {0x68db8bad, 8}; |
| |
| const DivMagicNumbers DivMagicNumberFor(int32_t divisor); |
| |
| |
| // The C++ standard leaves the semantics of '>>' undefined for |
| // negative signed operands. Most implementations do the right thing, |
| // though. |
| inline int ArithmeticShiftRight(int x, int s) { |
| return x >> s; |
| } |
| |
| |
| // Compute the 0-relative offset of some absolute value x of type T. |
| // This allows conversion of Addresses and integral types into |
| // 0-relative int offsets. |
| template <typename T> |
| inline intptr_t OffsetFrom(T x) { |
| return x - static_cast<T>(0); |
| } |
| |
| |
| // Compute the absolute value of type T for some 0-relative offset x. |
| // This allows conversion of 0-relative int offsets into Addresses and |
| // integral types. |
| template <typename T> |
| inline T AddressFrom(intptr_t x) { |
| return static_cast<T>(static_cast<T>(0) + x); |
| } |
| |
| |
| // Return the largest multiple of m which is <= x. |
| template <typename T> |
| inline T RoundDown(T x, intptr_t m) { |
| ASSERT(IsPowerOf2(m)); |
| return AddressFrom<T>(OffsetFrom(x) & -m); |
| } |
| |
| |
| // Return the smallest multiple of m which is >= x. |
| template <typename T> |
| inline T RoundUp(T x, intptr_t m) { |
| return RoundDown<T>(static_cast<T>(x + m - 1), m); |
| } |
| |
| |
| template <typename T> |
| int Compare(const T& a, const T& b) { |
| if (a == b) |
| return 0; |
| else if (a < b) |
| return -1; |
| else |
| return 1; |
| } |
| |
| |
| template <typename T> |
| int PointerValueCompare(const T* a, const T* b) { |
| return Compare<T>(*a, *b); |
| } |
| |
| |
| // Compare function to compare the object pointer value of two |
| // handlified objects. The handles are passed as pointers to the |
| // handles. |
| template<typename T> class Handle; // Forward declaration. |
| template <typename T> |
| int HandleObjectPointerCompare(const Handle<T>* a, const Handle<T>* b) { |
| return Compare<T*>(*(*a), *(*b)); |
| } |
| |
| |
| // Returns the smallest power of two which is >= x. If you pass in a |
| // number that is already a power of two, it is returned as is. |
| // Implementation is from "Hacker's Delight" by Henry S. Warren, Jr., |
| // figure 3-3, page 48, where the function is called clp2. |
| inline uint32_t RoundUpToPowerOf2(uint32_t x) { |
| ASSERT(x <= 0x80000000u); |
| x = x - 1; |
| x = x | (x >> 1); |
| x = x | (x >> 2); |
| x = x | (x >> 4); |
| x = x | (x >> 8); |
| x = x | (x >> 16); |
| return x + 1; |
| } |
| |
| |
| inline uint32_t RoundDownToPowerOf2(uint32_t x) { |
| uint32_t rounded_up = RoundUpToPowerOf2(x); |
| if (rounded_up > x) return rounded_up >> 1; |
| return rounded_up; |
| } |
| |
| |
| template <typename T, typename U> |
| inline bool IsAligned(T value, U alignment) { |
| return (value & (alignment - 1)) == 0; |
| } |
| |
| |
| // Returns true if (addr + offset) is aligned. |
| inline bool IsAddressAligned(Address addr, |
| intptr_t alignment, |
| int offset = 0) { |
| intptr_t offs = OffsetFrom(addr + offset); |
| return IsAligned(offs, alignment); |
| } |
| |
| |
| // Returns the maximum of the two parameters. |
| template <typename T> |
| T Max(T a, T b) { |
| return a < b ? b : a; |
| } |
| |
| |
| // Returns the minimum of the two parameters. |
| template <typename T> |
| T Min(T a, T b) { |
| return a < b ? a : b; |
| } |
| |
| |
| inline int StrLength(const char* string) { |
| size_t length = strlen(string); |
| ASSERT(length == static_cast<size_t>(static_cast<int>(length))); |
| return static_cast<int>(length); |
| } |
| |
| |
| // ---------------------------------------------------------------------------- |
| // BitField is a help template for encoding and decode bitfield with |
| // unsigned content. |
| template<class T, int shift, int size> |
| class BitField { |
| public: |
| // A uint32_t mask of bit field. To use all bits of a uint32 in a |
| // bitfield without compiler warnings we have to compute 2^32 without |
| // using a shift count of 32. |
| static const uint32_t kMask = ((1U << shift) << size) - (1U << shift); |
| static const uint32_t kShift = shift; |
| |
| // Value for the field with all bits set. |
| static const T kMax = static_cast<T>((1U << size) - 1); |
| |
| // Tells whether the provided value fits into the bit field. |
| static bool is_valid(T value) { |
| return (static_cast<uint32_t>(value) & ~static_cast<uint32_t>(kMax)) == 0; |
| } |
| |
| // Returns a uint32_t with the bit field value encoded. |
| static uint32_t encode(T value) { |
| ASSERT(is_valid(value)); |
| return static_cast<uint32_t>(value) << shift; |
| } |
| |
| // Returns a uint32_t with the bit field value updated. |
| static uint32_t update(uint32_t previous, T value) { |
| return (previous & ~kMask) | encode(value); |
| } |
| |
| // Extracts the bit field from the value. |
| static T decode(uint32_t value) { |
| return static_cast<T>((value & kMask) >> shift); |
| } |
| }; |
| |
| |
| // ---------------------------------------------------------------------------- |
| // Hash function. |
| |
| static const uint32_t kZeroHashSeed = 0; |
| |
| // Thomas Wang, Integer Hash Functions. |
| // http://www.concentric.net/~Ttwang/tech/inthash.htm |
| inline uint32_t ComputeIntegerHash(uint32_t key, uint32_t seed) { |
| uint32_t hash = key; |
| hash = hash ^ seed; |
| hash = ~hash + (hash << 15); // hash = (hash << 15) - hash - 1; |
| hash = hash ^ (hash >> 12); |
| hash = hash + (hash << 2); |
| hash = hash ^ (hash >> 4); |
| hash = hash * 2057; // hash = (hash + (hash << 3)) + (hash << 11); |
| hash = hash ^ (hash >> 16); |
| return hash; |
| } |
| |
| |
| inline uint32_t ComputeLongHash(uint64_t key) { |
| uint64_t hash = key; |
| hash = ~hash + (hash << 18); // hash = (hash << 18) - hash - 1; |
| hash = hash ^ (hash >> 31); |
| hash = hash * 21; // hash = (hash + (hash << 2)) + (hash << 4); |
| hash = hash ^ (hash >> 11); |
| hash = hash + (hash << 6); |
| hash = hash ^ (hash >> 22); |
| return static_cast<uint32_t>(hash); |
| } |
| |
| |
| inline uint32_t ComputePointerHash(void* ptr) { |
| return ComputeIntegerHash( |
| static_cast<uint32_t>(reinterpret_cast<intptr_t>(ptr)), |
| v8::internal::kZeroHashSeed); |
| } |
| |
| |
| // ---------------------------------------------------------------------------- |
| // Miscellaneous |
| |
| // A static resource holds a static instance that can be reserved in |
| // a local scope using an instance of Access. Attempts to re-reserve |
| // the instance will cause an error. |
| template <typename T> |
| class StaticResource { |
| public: |
| StaticResource() : is_reserved_(false) {} |
| |
| private: |
| template <typename S> friend class Access; |
| T instance_; |
| bool is_reserved_; |
| }; |
| |
| |
| // Locally scoped access to a static resource. |
| template <typename T> |
| class Access { |
| public: |
| explicit Access(StaticResource<T>* resource) |
| : resource_(resource) |
| , instance_(&resource->instance_) { |
| ASSERT(!resource->is_reserved_); |
| resource->is_reserved_ = true; |
| } |
| |
| ~Access() { |
| resource_->is_reserved_ = false; |
| resource_ = NULL; |
| instance_ = NULL; |
| } |
| |
| T* value() { return instance_; } |
| T* operator -> () { return instance_; } |
| |
| private: |
| StaticResource<T>* resource_; |
| T* instance_; |
| }; |
| |
| |
| template <typename T> |
| class Vector { |
| public: |
| Vector() : start_(NULL), length_(0) {} |
| Vector(T* data, int length) : start_(data), length_(length) { |
| ASSERT(length == 0 || (length > 0 && data != NULL)); |
| } |
| |
| static Vector<T> New(int length) { |
| return Vector<T>(NewArray<T>(length), length); |
| } |
| |
| // Returns a vector using the same backing storage as this one, |
| // spanning from and including 'from', to but not including 'to'. |
| Vector<T> SubVector(int from, int to) { |
| ASSERT(to <= length_); |
| ASSERT(from < to); |
| ASSERT(0 <= from); |
| return Vector<T>(start() + from, to - from); |
| } |
| |
| // Returns the length of the vector. |
| int length() const { return length_; } |
| |
| // Returns whether or not the vector is empty. |
| bool is_empty() const { return length_ == 0; } |
| |
| // Returns the pointer to the start of the data in the vector. |
| T* start() const { return start_; } |
| |
| // Access individual vector elements - checks bounds in debug mode. |
| T& operator[](int index) const { |
| ASSERT(0 <= index && index < length_); |
| return start_[index]; |
| } |
| |
| const T& at(int index) const { return operator[](index); } |
| |
| T& first() { return start_[0]; } |
| |
| T& last() { return start_[length_ - 1]; } |
| |
| // Returns a clone of this vector with a new backing store. |
| Vector<T> Clone() const { |
| T* result = NewArray<T>(length_); |
| for (int i = 0; i < length_; i++) result[i] = start_[i]; |
| return Vector<T>(result, length_); |
| } |
| |
| void Sort(int (*cmp)(const T*, const T*)) { |
| typedef int (*RawComparer)(const void*, const void*); |
| qsort(start(), |
| length(), |
| sizeof(T), |
| reinterpret_cast<RawComparer>(cmp)); |
| } |
| |
| void Sort() { |
| Sort(PointerValueCompare<T>); |
| } |
| |
| void Truncate(int length) { |
| ASSERT(length <= length_); |
| length_ = length; |
| } |
| |
| // Releases the array underlying this vector. Once disposed the |
| // vector is empty. |
| void Dispose() { |
| DeleteArray(start_); |
| start_ = NULL; |
| length_ = 0; |
| } |
| |
| inline Vector<T> operator+(int offset) { |
| ASSERT(offset < length_); |
| return Vector<T>(start_ + offset, length_ - offset); |
| } |
| |
| // Factory method for creating empty vectors. |
| static Vector<T> empty() { return Vector<T>(NULL, 0); } |
| |
| template<typename S> |
| static Vector<T> cast(Vector<S> input) { |
| return Vector<T>(reinterpret_cast<T*>(input.start()), |
| input.length() * sizeof(S) / sizeof(T)); |
| } |
| |
| protected: |
| void set_start(T* start) { start_ = start; } |
| |
| private: |
| T* start_; |
| int length_; |
| }; |
| |
| |
| // A pointer that can only be set once and doesn't allow NULL values. |
| template<typename T> |
| class SetOncePointer { |
| public: |
| SetOncePointer() : pointer_(NULL) { } |
| |
| bool is_set() const { return pointer_ != NULL; } |
| |
| T* get() const { |
| ASSERT(pointer_ != NULL); |
| return pointer_; |
| } |
| |
| void set(T* value) { |
| ASSERT(pointer_ == NULL && value != NULL); |
| pointer_ = value; |
| } |
| |
| private: |
| T* pointer_; |
| }; |
| |
| |
| template <typename T, int kSize> |
| class EmbeddedVector : public Vector<T> { |
| public: |
| EmbeddedVector() : Vector<T>(buffer_, kSize) { } |
| |
| explicit EmbeddedVector(T initial_value) : Vector<T>(buffer_, kSize) { |
| for (int i = 0; i < kSize; ++i) { |
| buffer_[i] = initial_value; |
| } |
| } |
| |
| // When copying, make underlying Vector to reference our buffer. |
| EmbeddedVector(const EmbeddedVector& rhs) |
| : Vector<T>(rhs) { |
| memcpy(buffer_, rhs.buffer_, sizeof(T) * kSize); |
| set_start(buffer_); |
| } |
| |
| EmbeddedVector& operator=(const EmbeddedVector& rhs) { |
| if (this == &rhs) return *this; |
| Vector<T>::operator=(rhs); |
| memcpy(buffer_, rhs.buffer_, sizeof(T) * kSize); |
| this->set_start(buffer_); |
| return *this; |
| } |
| |
| private: |
| T buffer_[kSize]; |
| }; |
| |
| |
| template <typename T> |
| class ScopedVector : public Vector<T> { |
| public: |
| explicit ScopedVector(int length) : Vector<T>(NewArray<T>(length), length) { } |
| ~ScopedVector() { |
| DeleteArray(this->start()); |
| } |
| |
| private: |
| DISALLOW_IMPLICIT_CONSTRUCTORS(ScopedVector); |
| }; |
| |
| #define STATIC_ASCII_VECTOR(x) \ |
| v8::internal::Vector<const uint8_t>(reinterpret_cast<const uint8_t*>(x), \ |
| ARRAY_SIZE(x)-1) |
| |
| inline Vector<const char> CStrVector(const char* data) { |
| return Vector<const char>(data, StrLength(data)); |
| } |
| |
| inline Vector<const uint8_t> OneByteVector(const char* data, int length) { |
| return Vector<const uint8_t>(reinterpret_cast<const uint8_t*>(data), length); |
| } |
| |
| inline Vector<const uint8_t> OneByteVector(const char* data) { |
| return OneByteVector(data, StrLength(data)); |
| } |
| |
| inline Vector<char> MutableCStrVector(char* data) { |
| return Vector<char>(data, StrLength(data)); |
| } |
| |
| inline Vector<char> MutableCStrVector(char* data, int max) { |
| int length = StrLength(data); |
| return Vector<char>(data, (length < max) ? length : max); |
| } |
| |
| |
| /* |
| * A class that collects values into a backing store. |
| * Specialized versions of the class can allow access to the backing store |
| * in different ways. |
| * There is no guarantee that the backing store is contiguous (and, as a |
| * consequence, no guarantees that consecutively added elements are adjacent |
| * in memory). The collector may move elements unless it has guaranteed not |
| * to. |
| */ |
| template <typename T, int growth_factor = 2, int max_growth = 1 * MB> |
| class Collector { |
| public: |
| explicit Collector(int initial_capacity = kMinCapacity) |
| : index_(0), size_(0) { |
| current_chunk_ = Vector<T>::New(initial_capacity); |
| } |
| |
| virtual ~Collector() { |
| // Free backing store (in reverse allocation order). |
| current_chunk_.Dispose(); |
| for (int i = chunks_.length() - 1; i >= 0; i--) { |
| chunks_.at(i).Dispose(); |
| } |
| } |
| |
| // Add a single element. |
| inline void Add(T value) { |
| if (index_ >= current_chunk_.length()) { |
| Grow(1); |
| } |
| current_chunk_[index_] = value; |
| index_++; |
| size_++; |
| } |
| |
| // Add a block of contiguous elements and return a Vector backed by the |
| // memory area. |
| // A basic Collector will keep this vector valid as long as the Collector |
| // is alive. |
| inline Vector<T> AddBlock(int size, T initial_value) { |
| ASSERT(size > 0); |
| if (size > current_chunk_.length() - index_) { |
| Grow(size); |
| } |
| T* position = current_chunk_.start() + index_; |
| index_ += size; |
| size_ += size; |
| for (int i = 0; i < size; i++) { |
| position[i] = initial_value; |
| } |
| return Vector<T>(position, size); |
| } |
| |
| |
| // Add a contiguous block of elements and return a vector backed |
| // by the added block. |
| // A basic Collector will keep this vector valid as long as the Collector |
| // is alive. |
| inline Vector<T> AddBlock(Vector<const T> source) { |
| if (source.length() > current_chunk_.length() - index_) { |
| Grow(source.length()); |
| } |
| T* position = current_chunk_.start() + index_; |
| index_ += source.length(); |
| size_ += source.length(); |
| for (int i = 0; i < source.length(); i++) { |
| position[i] = source[i]; |
| } |
| return Vector<T>(position, source.length()); |
| } |
| |
| |
| // Write the contents of the collector into the provided vector. |
| void WriteTo(Vector<T> destination) { |
| ASSERT(size_ <= destination.length()); |
| int position = 0; |
| for (int i = 0; i < chunks_.length(); i++) { |
| Vector<T> chunk = chunks_.at(i); |
| for (int j = 0; j < chunk.length(); j++) { |
| destination[position] = chunk[j]; |
| position++; |
| } |
| } |
| for (int i = 0; i < index_; i++) { |
| destination[position] = current_chunk_[i]; |
| position++; |
| } |
| } |
| |
| // Allocate a single contiguous vector, copy all the collected |
| // elements to the vector, and return it. |
| // The caller is responsible for freeing the memory of the returned |
| // vector (e.g., using Vector::Dispose). |
| Vector<T> ToVector() { |
| Vector<T> new_store = Vector<T>::New(size_); |
| WriteTo(new_store); |
| return new_store; |
| } |
| |
| // Resets the collector to be empty. |
| virtual void Reset(); |
| |
| // Total number of elements added to collector so far. |
| inline int size() { return size_; } |
| |
| protected: |
| static const int kMinCapacity = 16; |
| List<Vector<T> > chunks_; |
| Vector<T> current_chunk_; // Block of memory currently being written into. |
| int index_; // Current index in current chunk. |
| int size_; // Total number of elements in collector. |
| |
| // Creates a new current chunk, and stores the old chunk in the chunks_ list. |
| void Grow(int min_capacity) { |
| ASSERT(growth_factor > 1); |
| int new_capacity; |
| int current_length = current_chunk_.length(); |
| if (current_length < kMinCapacity) { |
| // The collector started out as empty. |
| new_capacity = min_capacity * growth_factor; |
| if (new_capacity < kMinCapacity) new_capacity = kMinCapacity; |
| } else { |
| int growth = current_length * (growth_factor - 1); |
| if (growth > max_growth) { |
| growth = max_growth; |
| } |
| new_capacity = current_length + growth; |
| if (new_capacity < min_capacity) { |
| new_capacity = min_capacity + growth; |
| } |
| } |
| NewChunk(new_capacity); |
| ASSERT(index_ + min_capacity <= current_chunk_.length()); |
| } |
| |
| // Before replacing the current chunk, give a subclass the option to move |
| // some of the current data into the new chunk. The function may update |
| // the current index_ value to represent data no longer in the current chunk. |
| // Returns the initial index of the new chunk (after copied data). |
| virtual void NewChunk(int new_capacity) { |
| Vector<T> new_chunk = Vector<T>::New(new_capacity); |
| if (index_ > 0) { |
| chunks_.Add(current_chunk_.SubVector(0, index_)); |
| } else { |
| current_chunk_.Dispose(); |
| } |
| current_chunk_ = new_chunk; |
| index_ = 0; |
| } |
| }; |
| |
| |
| /* |
| * A collector that allows sequences of values to be guaranteed to |
| * stay consecutive. |
| * If the backing store grows while a sequence is active, the current |
| * sequence might be moved, but after the sequence is ended, it will |
| * not move again. |
| * NOTICE: Blocks allocated using Collector::AddBlock(int) can move |
| * as well, if inside an active sequence where another element is added. |
| */ |
| template <typename T, int growth_factor = 2, int max_growth = 1 * MB> |
| class SequenceCollector : public Collector<T, growth_factor, max_growth> { |
| public: |
| explicit SequenceCollector(int initial_capacity) |
| : Collector<T, growth_factor, max_growth>(initial_capacity), |
| sequence_start_(kNoSequence) { } |
| |
| virtual ~SequenceCollector() {} |
| |
| void StartSequence() { |
| ASSERT(sequence_start_ == kNoSequence); |
| sequence_start_ = this->index_; |
| } |
| |
| Vector<T> EndSequence() { |
| ASSERT(sequence_start_ != kNoSequence); |
| int sequence_start = sequence_start_; |
| sequence_start_ = kNoSequence; |
| if (sequence_start == this->index_) return Vector<T>(); |
| return this->current_chunk_.SubVector(sequence_start, this->index_); |
| } |
| |
| // Drops the currently added sequence, and all collected elements in it. |
| void DropSequence() { |
| ASSERT(sequence_start_ != kNoSequence); |
| int sequence_length = this->index_ - sequence_start_; |
| this->index_ = sequence_start_; |
| this->size_ -= sequence_length; |
| sequence_start_ = kNoSequence; |
| } |
| |
| virtual void Reset() { |
| sequence_start_ = kNoSequence; |
| this->Collector<T, growth_factor, max_growth>::Reset(); |
| } |
| |
| private: |
| static const int kNoSequence = -1; |
| int sequence_start_; |
| |
| // Move the currently active sequence to the new chunk. |
| virtual void NewChunk(int new_capacity) { |
| if (sequence_start_ == kNoSequence) { |
| // Fall back on default behavior if no sequence has been started. |
| this->Collector<T, growth_factor, max_growth>::NewChunk(new_capacity); |
| return; |
| } |
| int sequence_length = this->index_ - sequence_start_; |
| Vector<T> new_chunk = Vector<T>::New(sequence_length + new_capacity); |
| ASSERT(sequence_length < new_chunk.length()); |
| for (int i = 0; i < sequence_length; i++) { |
| new_chunk[i] = this->current_chunk_[sequence_start_ + i]; |
| } |
| if (sequence_start_ > 0) { |
| this->chunks_.Add(this->current_chunk_.SubVector(0, sequence_start_)); |
| } else { |
| this->current_chunk_.Dispose(); |
| } |
| this->current_chunk_ = new_chunk; |
| this->index_ = sequence_length; |
| sequence_start_ = 0; |
| } |
| }; |
| |
| |
| // Compare ASCII/16bit chars to ASCII/16bit chars. |
| template <typename lchar, typename rchar> |
| inline int CompareCharsUnsigned(const lchar* lhs, |
| const rchar* rhs, |
| int chars) { |
| const lchar* limit = lhs + chars; |
| #ifdef V8_HOST_CAN_READ_UNALIGNED |
| if (sizeof(*lhs) == sizeof(*rhs)) { |
| // Number of characters in a uintptr_t. |
| static const int kStepSize = sizeof(uintptr_t) / sizeof(*lhs); // NOLINT |
| while (lhs <= limit - kStepSize) { |
| if (*reinterpret_cast<const uintptr_t*>(lhs) != |
| *reinterpret_cast<const uintptr_t*>(rhs)) { |
| break; |
| } |
| lhs += kStepSize; |
| rhs += kStepSize; |
| } |
| } |
| #endif |
| while (lhs < limit) { |
| int r = static_cast<int>(*lhs) - static_cast<int>(*rhs); |
| if (r != 0) return r; |
| ++lhs; |
| ++rhs; |
| } |
| return 0; |
| } |
| |
| template<typename lchar, typename rchar> |
| inline int CompareChars(const lchar* lhs, const rchar* rhs, int chars) { |
| ASSERT(sizeof(lchar) <= 2); |
| ASSERT(sizeof(rchar) <= 2); |
| if (sizeof(lchar) == 1) { |
| if (sizeof(rchar) == 1) { |
| return CompareCharsUnsigned(reinterpret_cast<const uint8_t*>(lhs), |
| reinterpret_cast<const uint8_t*>(rhs), |
| chars); |
| } else { |
| return CompareCharsUnsigned(reinterpret_cast<const uint8_t*>(lhs), |
| reinterpret_cast<const uint16_t*>(rhs), |
| chars); |
| } |
| } else { |
| if (sizeof(rchar) == 1) { |
| return CompareCharsUnsigned(reinterpret_cast<const uint16_t*>(lhs), |
| reinterpret_cast<const uint8_t*>(rhs), |
| chars); |
| } else { |
| return CompareCharsUnsigned(reinterpret_cast<const uint16_t*>(lhs), |
| reinterpret_cast<const uint16_t*>(rhs), |
| chars); |
| } |
| } |
| } |
| |
| |
| // Calculate 10^exponent. |
| inline int TenToThe(int exponent) { |
| ASSERT(exponent <= 9); |
| ASSERT(exponent >= 1); |
| int answer = 10; |
| for (int i = 1; i < exponent; i++) answer *= 10; |
| return answer; |
| } |
| |
| |
| // The type-based aliasing rule allows the compiler to assume that pointers of |
| // different types (for some definition of different) never alias each other. |
| // Thus the following code does not work: |
| // |
| // float f = foo(); |
| // int fbits = *(int*)(&f); |
| // |
| // The compiler 'knows' that the int pointer can't refer to f since the types |
| // don't match, so the compiler may cache f in a register, leaving random data |
| // in fbits. Using C++ style casts makes no difference, however a pointer to |
| // char data is assumed to alias any other pointer. This is the 'memcpy |
| // exception'. |
| // |
| // Bit_cast uses the memcpy exception to move the bits from a variable of one |
| // type of a variable of another type. Of course the end result is likely to |
| // be implementation dependent. Most compilers (gcc-4.2 and MSVC 2005) |
| // will completely optimize BitCast away. |
| // |
| // There is an additional use for BitCast. |
| // Recent gccs will warn when they see casts that may result in breakage due to |
| // the type-based aliasing rule. If you have checked that there is no breakage |
| // you can use BitCast to cast one pointer type to another. This confuses gcc |
| // enough that it can no longer see that you have cast one pointer type to |
| // another thus avoiding the warning. |
| |
| // We need different implementations of BitCast for pointer and non-pointer |
| // values. We use partial specialization of auxiliary struct to work around |
| // issues with template functions overloading. |
| template <class Dest, class Source> |
| struct BitCastHelper { |
| STATIC_ASSERT(sizeof(Dest) == sizeof(Source)); |
| |
| INLINE(static Dest cast(const Source& source)) { |
| Dest dest; |
| memcpy(&dest, &source, sizeof(dest)); |
| return dest; |
| } |
| }; |
| |
| template <class Dest, class Source> |
| struct BitCastHelper<Dest, Source*> { |
| INLINE(static Dest cast(Source* source)) { |
| return BitCastHelper<Dest, uintptr_t>:: |
| cast(reinterpret_cast<uintptr_t>(source)); |
| } |
| }; |
| |
| template <class Dest, class Source> |
| INLINE(Dest BitCast(const Source& source)); |
| |
| template <class Dest, class Source> |
| inline Dest BitCast(const Source& source) { |
| return BitCastHelper<Dest, Source>::cast(source); |
| } |
| |
| |
| template<typename ElementType, int NumElements> |
| class EmbeddedContainer { |
| public: |
| EmbeddedContainer() : elems_() { } |
| |
| int length() const { return NumElements; } |
| const ElementType& operator[](int i) const { |
| ASSERT(i < length()); |
| return elems_[i]; |
| } |
| ElementType& operator[](int i) { |
| ASSERT(i < length()); |
| return elems_[i]; |
| } |
| |
| private: |
| ElementType elems_[NumElements]; |
| }; |
| |
| |
| template<typename ElementType> |
| class EmbeddedContainer<ElementType, 0> { |
| public: |
| int length() const { return 0; } |
| const ElementType& operator[](int i) const { |
| UNREACHABLE(); |
| static ElementType t = 0; |
| return t; |
| } |
| ElementType& operator[](int i) { |
| UNREACHABLE(); |
| static ElementType t = 0; |
| return t; |
| } |
| }; |
| |
| |
| // Helper class for building result strings in a character buffer. The |
| // purpose of the class is to use safe operations that checks the |
| // buffer bounds on all operations in debug mode. |
| // This simple base class does not allow formatted output. |
| class SimpleStringBuilder { |
| public: |
| // Create a string builder with a buffer of the given size. The |
| // buffer is allocated through NewArray<char> and must be |
| // deallocated by the caller of Finalize(). |
| explicit SimpleStringBuilder(int size); |
| |
| SimpleStringBuilder(char* buffer, int size) |
| : buffer_(buffer, size), position_(0) { } |
| |
| ~SimpleStringBuilder() { if (!is_finalized()) Finalize(); } |
| |
| int size() const { return buffer_.length(); } |
| |
| // Get the current position in the builder. |
| int position() const { |
| ASSERT(!is_finalized()); |
| return position_; |
| } |
| |
| // Reset the position. |
| void Reset() { position_ = 0; } |
| |
| // Add a single character to the builder. It is not allowed to add |
| // 0-characters; use the Finalize() method to terminate the string |
| // instead. |
| void AddCharacter(char c) { |
| ASSERT(c != '\0'); |
| ASSERT(!is_finalized() && position_ < buffer_.length()); |
| buffer_[position_++] = c; |
| } |
| |
| // Add an entire string to the builder. Uses strlen() internally to |
| // compute the length of the input string. |
| void AddString(const char* s); |
| |
| // Add the first 'n' characters of the given string 's' to the |
| // builder. The input string must have enough characters. |
| void AddSubstring(const char* s, int n); |
| |
| // Add character padding to the builder. If count is non-positive, |
| // nothing is added to the builder. |
| void AddPadding(char c, int count); |
| |
| // Add the decimal representation of the value. |
| void AddDecimalInteger(int value); |
| |
| // Finalize the string by 0-terminating it and returning the buffer. |
| char* Finalize(); |
| |
| protected: |
| Vector<char> buffer_; |
| int position_; |
| |
| bool is_finalized() const { return position_ < 0; } |
| |
| private: |
| DISALLOW_IMPLICIT_CONSTRUCTORS(SimpleStringBuilder); |
| }; |
| |
| |
| // A poor man's version of STL's bitset: A bit set of enums E (without explicit |
| // values), fitting into an integral type T. |
| template <class E, class T = int> |
| class EnumSet { |
| public: |
| explicit EnumSet(T bits = 0) : bits_(bits) {} |
| bool IsEmpty() const { return bits_ == 0; } |
| bool Contains(E element) const { return (bits_ & Mask(element)) != 0; } |
| bool ContainsAnyOf(const EnumSet& set) const { |
| return (bits_ & set.bits_) != 0; |
| } |
| void Add(E element) { bits_ |= Mask(element); } |
| void Add(const EnumSet& set) { bits_ |= set.bits_; } |
| void Remove(E element) { bits_ &= ~Mask(element); } |
| void Remove(const EnumSet& set) { bits_ &= ~set.bits_; } |
| void RemoveAll() { bits_ = 0; } |
| void Intersect(const EnumSet& set) { bits_ &= set.bits_; } |
| T ToIntegral() const { return bits_; } |
| bool operator==(const EnumSet& set) { return bits_ == set.bits_; } |
| |
| private: |
| T Mask(E element) const { |
| // The strange typing in ASSERT is necessary to avoid stupid warnings, see: |
| // http://gcc.gnu.org/bugzilla/show_bug.cgi?id=43680 |
| ASSERT(static_cast<int>(element) < static_cast<int>(sizeof(T) * CHAR_BIT)); |
| return 1 << element; |
| } |
| |
| T bits_; |
| }; |
| |
| |
| class TypeFeedbackId { |
| public: |
| explicit TypeFeedbackId(int id) : id_(id) { } |
| int ToInt() const { return id_; } |
| |
| static TypeFeedbackId None() { return TypeFeedbackId(kNoneId); } |
| bool IsNone() const { return id_ == kNoneId; } |
| |
| private: |
| static const int kNoneId = -1; |
| |
| int id_; |
| }; |
| |
| |
| class BailoutId { |
| public: |
| explicit BailoutId(int id) : id_(id) { } |
| int ToInt() const { return id_; } |
| |
| static BailoutId None() { return BailoutId(kNoneId); } |
| static BailoutId FunctionEntry() { return BailoutId(kFunctionEntryId); } |
| static BailoutId Declarations() { return BailoutId(kDeclarationsId); } |
| static BailoutId FirstUsable() { return BailoutId(kFirstUsableId); } |
| static BailoutId StubEntry() { return BailoutId(kStubEntryId); } |
| |
| bool IsNone() const { return id_ == kNoneId; } |
| bool operator==(const BailoutId& other) const { return id_ == other.id_; } |
| |
| private: |
| static const int kNoneId = -1; |
| |
| // Using 0 could disguise errors. |
| static const int kFunctionEntryId = 2; |
| |
| // This AST id identifies the point after the declarations have been visited. |
| // We need it to capture the environment effects of declarations that emit |
| // code (function declarations). |
| static const int kDeclarationsId = 3; |
| |
| // Every FunctionState starts with this id. |
| static const int kFirstUsableId = 4; |
| |
| // Every compiled stub starts with this id. |
| static const int kStubEntryId = 5; |
| |
| int id_; |
| }; |
| |
| } } // namespace v8::internal |
| |
| #endif // V8_UTILS_H_ |