upload android base code part3
This commit is contained in:
August
parent
71b83c22f1
commit
b9e30e05b1
15122 changed files with 2089659 additions and 0 deletions
343
android/art/runtime/leb128.h
Normal file
343
android/art/runtime/leb128.h
Normal file
|
|
@ -0,0 +1,343 @@
|
|||
/*
|
||||
* Copyright (C) 2011 The Android Open Source Project
|
||||
*
|
||||
* Licensed under the Apache License, Version 2.0 (the "License");
|
||||
* you may not use this file except in compliance with the License.
|
||||
* You may obtain a copy of the License at
|
||||
*
|
||||
* http://www.apache.org/licenses/LICENSE-2.0
|
||||
*
|
||||
* Unless required by applicable law or agreed to in writing, software
|
||||
* distributed under the License is distributed on an "AS IS" BASIS,
|
||||
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
|
||||
* See the License for the specific language governing permissions and
|
||||
* limitations under the License.
|
||||
*/
|
||||
|
||||
#ifndef ART_RUNTIME_LEB128_H_
|
||||
#define ART_RUNTIME_LEB128_H_
|
||||
|
||||
#include <vector>
|
||||
|
||||
#include "base/bit_utils.h"
|
||||
#include "base/logging.h"
|
||||
#include "globals.h"
|
||||
|
||||
namespace art {
|
||||
|
||||
// Reads an unsigned LEB128 value, updating the given pointer to point
|
||||
// just past the end of the read value. This function tolerates
|
||||
// non-zero high-order bits in the fifth encoded byte.
|
||||
static inline uint32_t DecodeUnsignedLeb128(const uint8_t** data) {
|
||||
const uint8_t* ptr = *data;
|
||||
int result = *(ptr++);
|
||||
if (UNLIKELY(result > 0x7f)) {
|
||||
int cur = *(ptr++);
|
||||
result = (result & 0x7f) | ((cur & 0x7f) << 7);
|
||||
if (cur > 0x7f) {
|
||||
cur = *(ptr++);
|
||||
result |= (cur & 0x7f) << 14;
|
||||
if (cur > 0x7f) {
|
||||
cur = *(ptr++);
|
||||
result |= (cur & 0x7f) << 21;
|
||||
if (cur > 0x7f) {
|
||||
// Note: We don't check to see if cur is out of range here,
|
||||
// meaning we tolerate garbage in the four high-order bits.
|
||||
cur = *(ptr++);
|
||||
result |= cur << 28;
|
||||
}
|
||||
}
|
||||
}
|
||||
}
|
||||
*data = ptr;
|
||||
return static_cast<uint32_t>(result);
|
||||
}
|
||||
|
||||
static inline bool DecodeUnsignedLeb128Checked(const uint8_t** data,
|
||||
const void* end,
|
||||
uint32_t* out) {
|
||||
const uint8_t* ptr = *data;
|
||||
if (ptr >= end) {
|
||||
return false;
|
||||
}
|
||||
int result = *(ptr++);
|
||||
if (UNLIKELY(result > 0x7f)) {
|
||||
if (ptr >= end) {
|
||||
return false;
|
||||
}
|
||||
int cur = *(ptr++);
|
||||
result = (result & 0x7f) | ((cur & 0x7f) << 7);
|
||||
if (cur > 0x7f) {
|
||||
if (ptr >= end) {
|
||||
return false;
|
||||
}
|
||||
cur = *(ptr++);
|
||||
result |= (cur & 0x7f) << 14;
|
||||
if (cur > 0x7f) {
|
||||
if (ptr >= end) {
|
||||
return false;
|
||||
}
|
||||
cur = *(ptr++);
|
||||
result |= (cur & 0x7f) << 21;
|
||||
if (cur > 0x7f) {
|
||||
if (ptr >= end) {
|
||||
return false;
|
||||
}
|
||||
// Note: We don't check to see if cur is out of range here,
|
||||
// meaning we tolerate garbage in the four high-order bits.
|
||||
cur = *(ptr++);
|
||||
result |= cur << 28;
|
||||
}
|
||||
}
|
||||
}
|
||||
}
|
||||
*data = ptr;
|
||||
*out = static_cast<uint32_t>(result);
|
||||
return true;
|
||||
}
|
||||
|
||||
// Reads an unsigned LEB128 + 1 value. updating the given pointer to point
|
||||
// just past the end of the read value. This function tolerates
|
||||
// non-zero high-order bits in the fifth encoded byte.
|
||||
// It is possible for this function to return -1.
|
||||
static inline int32_t DecodeUnsignedLeb128P1(const uint8_t** data) {
|
||||
return DecodeUnsignedLeb128(data) - 1;
|
||||
}
|
||||
|
||||
// Reads a signed LEB128 value, updating the given pointer to point
|
||||
// just past the end of the read value. This function tolerates
|
||||
// non-zero high-order bits in the fifth encoded byte.
|
||||
static inline int32_t DecodeSignedLeb128(const uint8_t** data) {
|
||||
const uint8_t* ptr = *data;
|
||||
int32_t result = *(ptr++);
|
||||
if (result <= 0x7f) {
|
||||
result = (result << 25) >> 25;
|
||||
} else {
|
||||
int cur = *(ptr++);
|
||||
result = (result & 0x7f) | ((cur & 0x7f) << 7);
|
||||
if (cur <= 0x7f) {
|
||||
result = (result << 18) >> 18;
|
||||
} else {
|
||||
cur = *(ptr++);
|
||||
result |= (cur & 0x7f) << 14;
|
||||
if (cur <= 0x7f) {
|
||||
result = (result << 11) >> 11;
|
||||
} else {
|
||||
cur = *(ptr++);
|
||||
result |= (cur & 0x7f) << 21;
|
||||
if (cur <= 0x7f) {
|
||||
result = (result << 4) >> 4;
|
||||
} else {
|
||||
// Note: We don't check to see if cur is out of range here,
|
||||
// meaning we tolerate garbage in the four high-order bits.
|
||||
cur = *(ptr++);
|
||||
result |= cur << 28;
|
||||
}
|
||||
}
|
||||
}
|
||||
}
|
||||
*data = ptr;
|
||||
return result;
|
||||
}
|
||||
|
||||
static inline bool DecodeSignedLeb128Checked(const uint8_t** data,
|
||||
const void* end,
|
||||
int32_t* out) {
|
||||
const uint8_t* ptr = *data;
|
||||
if (ptr >= end) {
|
||||
return false;
|
||||
}
|
||||
int32_t result = *(ptr++);
|
||||
if (result <= 0x7f) {
|
||||
result = (result << 25) >> 25;
|
||||
} else {
|
||||
if (ptr >= end) {
|
||||
return false;
|
||||
}
|
||||
int cur = *(ptr++);
|
||||
result = (result & 0x7f) | ((cur & 0x7f) << 7);
|
||||
if (cur <= 0x7f) {
|
||||
result = (result << 18) >> 18;
|
||||
} else {
|
||||
if (ptr >= end) {
|
||||
return false;
|
||||
}
|
||||
cur = *(ptr++);
|
||||
result |= (cur & 0x7f) << 14;
|
||||
if (cur <= 0x7f) {
|
||||
result = (result << 11) >> 11;
|
||||
} else {
|
||||
if (ptr >= end) {
|
||||
return false;
|
||||
}
|
||||
cur = *(ptr++);
|
||||
result |= (cur & 0x7f) << 21;
|
||||
if (cur <= 0x7f) {
|
||||
result = (result << 4) >> 4;
|
||||
} else {
|
||||
if (ptr >= end) {
|
||||
return false;
|
||||
}
|
||||
// Note: We don't check to see if cur is out of range here,
|
||||
// meaning we tolerate garbage in the four high-order bits.
|
||||
cur = *(ptr++);
|
||||
result |= cur << 28;
|
||||
}
|
||||
}
|
||||
}
|
||||
}
|
||||
*data = ptr;
|
||||
*out = static_cast<uint32_t>(result);
|
||||
return true;
|
||||
}
|
||||
|
||||
// Returns the number of bytes needed to encode the value in unsigned LEB128.
|
||||
static inline uint32_t UnsignedLeb128Size(uint32_t data) {
|
||||
// bits_to_encode = (data != 0) ? 32 - CLZ(x) : 1 // 32 - CLZ(data | 1)
|
||||
// bytes = ceil(bits_to_encode / 7.0); // (6 + bits_to_encode) / 7
|
||||
uint32_t x = 6 + 32 - CLZ(data | 1U);
|
||||
// Division by 7 is done by (x * 37) >> 8 where 37 = ceil(256 / 7).
|
||||
// This works for 0 <= x < 256 / (7 * 37 - 256), i.e. 0 <= x <= 85.
|
||||
return (x * 37) >> 8;
|
||||
}
|
||||
|
||||
// Returns the number of bytes needed to encode the value in unsigned LEB128.
|
||||
static inline uint32_t SignedLeb128Size(int32_t data) {
|
||||
// Like UnsignedLeb128Size(), but we need one bit beyond the highest bit that differs from sign.
|
||||
data = data ^ (data >> 31);
|
||||
uint32_t x = 1 /* we need to encode the sign bit */ + 6 + 32 - CLZ(data | 1U);
|
||||
return (x * 37) >> 8;
|
||||
}
|
||||
|
||||
static inline uint8_t* EncodeUnsignedLeb128(uint8_t* dest, uint32_t value) {
|
||||
uint8_t out = value & 0x7f;
|
||||
value >>= 7;
|
||||
while (value != 0) {
|
||||
*dest++ = out | 0x80;
|
||||
out = value & 0x7f;
|
||||
value >>= 7;
|
||||
}
|
||||
*dest++ = out;
|
||||
return dest;
|
||||
}
|
||||
|
||||
template <typename Vector>
|
||||
static inline void EncodeUnsignedLeb128(Vector* dest, uint32_t value) {
|
||||
static_assert(std::is_same<typename Vector::value_type, uint8_t>::value, "Invalid value type");
|
||||
uint8_t out = value & 0x7f;
|
||||
value >>= 7;
|
||||
while (value != 0) {
|
||||
dest->push_back(out | 0x80);
|
||||
out = value & 0x7f;
|
||||
value >>= 7;
|
||||
}
|
||||
dest->push_back(out);
|
||||
}
|
||||
|
||||
// Overwrite encoded Leb128 with a new value. The new value must be less than
|
||||
// or equal to the old value to ensure that it fits the allocated space.
|
||||
static inline void UpdateUnsignedLeb128(uint8_t* dest, uint32_t value) {
|
||||
const uint8_t* old_end = dest;
|
||||
uint32_t old_value = DecodeUnsignedLeb128(&old_end);
|
||||
DCHECK_LE(value, old_value);
|
||||
for (uint8_t* end = EncodeUnsignedLeb128(dest, value); end < old_end; end++) {
|
||||
// Use longer encoding than necessary to fill the allocated space.
|
||||
end[-1] |= 0x80;
|
||||
end[0] = 0;
|
||||
}
|
||||
}
|
||||
|
||||
static inline uint8_t* EncodeSignedLeb128(uint8_t* dest, int32_t value) {
|
||||
uint32_t extra_bits = static_cast<uint32_t>(value ^ (value >> 31)) >> 6;
|
||||
uint8_t out = value & 0x7f;
|
||||
while (extra_bits != 0u) {
|
||||
*dest++ = out | 0x80;
|
||||
value >>= 7;
|
||||
out = value & 0x7f;
|
||||
extra_bits >>= 7;
|
||||
}
|
||||
*dest++ = out;
|
||||
return dest;
|
||||
}
|
||||
|
||||
template<typename Vector>
|
||||
static inline void EncodeSignedLeb128(Vector* dest, int32_t value) {
|
||||
static_assert(std::is_same<typename Vector::value_type, uint8_t>::value, "Invalid value type");
|
||||
uint32_t extra_bits = static_cast<uint32_t>(value ^ (value >> 31)) >> 6;
|
||||
uint8_t out = value & 0x7f;
|
||||
while (extra_bits != 0u) {
|
||||
dest->push_back(out | 0x80);
|
||||
value >>= 7;
|
||||
out = value & 0x7f;
|
||||
extra_bits >>= 7;
|
||||
}
|
||||
dest->push_back(out);
|
||||
}
|
||||
|
||||
// An encoder that pushes int32_t/uint32_t data onto the given std::vector.
|
||||
template <typename Vector = std::vector<uint8_t>>
|
||||
class Leb128Encoder {
|
||||
static_assert(std::is_same<typename Vector::value_type, uint8_t>::value, "Invalid value type");
|
||||
|
||||
public:
|
||||
explicit Leb128Encoder(Vector* data) : data_(data) {
|
||||
DCHECK(data != nullptr);
|
||||
}
|
||||
|
||||
void Reserve(uint32_t size) {
|
||||
data_->reserve(size);
|
||||
}
|
||||
|
||||
void PushBackUnsigned(uint32_t value) {
|
||||
EncodeUnsignedLeb128(data_, value);
|
||||
}
|
||||
|
||||
template<typename It>
|
||||
void InsertBackUnsigned(It cur, It end) {
|
||||
for (; cur != end; ++cur) {
|
||||
PushBackUnsigned(*cur);
|
||||
}
|
||||
}
|
||||
|
||||
void PushBackSigned(int32_t value) {
|
||||
EncodeSignedLeb128(data_, value);
|
||||
}
|
||||
|
||||
template<typename It>
|
||||
void InsertBackSigned(It cur, It end) {
|
||||
for (; cur != end; ++cur) {
|
||||
PushBackSigned(*cur);
|
||||
}
|
||||
}
|
||||
|
||||
const Vector& GetData() const {
|
||||
return *data_;
|
||||
}
|
||||
|
||||
protected:
|
||||
Vector* const data_;
|
||||
|
||||
private:
|
||||
DISALLOW_COPY_AND_ASSIGN(Leb128Encoder);
|
||||
};
|
||||
|
||||
// An encoder with an API similar to vector<uint32_t> where the data is captured in ULEB128 format.
|
||||
template <typename Vector = std::vector<uint8_t>>
|
||||
class Leb128EncodingVector FINAL : private Vector,
|
||||
public Leb128Encoder<Vector> {
|
||||
static_assert(std::is_same<typename Vector::value_type, uint8_t>::value, "Invalid value type");
|
||||
|
||||
public:
|
||||
Leb128EncodingVector() : Leb128Encoder<Vector>(this) { }
|
||||
|
||||
explicit Leb128EncodingVector(const typename Vector::allocator_type& alloc)
|
||||
: Vector(alloc),
|
||||
Leb128Encoder<Vector>(this) { }
|
||||
|
||||
private:
|
||||
DISALLOW_COPY_AND_ASSIGN(Leb128EncodingVector);
|
||||
};
|
||||
|
||||
} // namespace art
|
||||
|
||||
#endif // ART_RUNTIME_LEB128_H_
|
||||
Loading…
Add table
Add a link
Reference in a new issue