103 строки
2.8 KiB
C++
103 строки
2.8 KiB
C++
// Copyright (c) 2018 Google LLC
|
|
//
|
|
// 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 LIBSPIRV_UTILS_BIT_VECTOR_H_
|
|
#define LIBSPIRV_UTILS_BIT_VECTOR_H_
|
|
|
|
#include <cstdint>
|
|
#include <iosfwd>
|
|
#include <vector>
|
|
|
|
namespace spvtools {
|
|
namespace utils {
|
|
|
|
// Implements a bit vector class.
|
|
//
|
|
// All bits default to zero, and the upper bound is 2^32-1.
|
|
class BitVector {
|
|
private:
|
|
using BitContainer = uint64_t;
|
|
enum { kBitContainerSize = 64 };
|
|
enum { kInitialNumBits = 1024 };
|
|
|
|
public:
|
|
// Creates a bit vector contianing 0s.
|
|
BitVector() : bits_(kInitialNumBits / kBitContainerSize, 0) {}
|
|
|
|
// Sets the |i|th bit to 1. Returns the |i|th bit before it was set.
|
|
bool Set(uint32_t i) {
|
|
uint32_t element_index = i / kBitContainerSize;
|
|
uint32_t bit_in_element = i % kBitContainerSize;
|
|
|
|
if (element_index >= bits_.size()) {
|
|
bits_.resize(element_index + 1, 0);
|
|
}
|
|
|
|
BitContainer original = bits_[element_index];
|
|
BitContainer ith_bit = static_cast<BitContainer>(1) << bit_in_element;
|
|
|
|
if ((original & ith_bit) != 0) {
|
|
return true;
|
|
} else {
|
|
bits_[element_index] = original | ith_bit;
|
|
return false;
|
|
}
|
|
}
|
|
|
|
// Sets the |i|th bit to 0. Return the |i|th bit before it was cleared.
|
|
bool Clear(uint32_t i) {
|
|
uint32_t element_index = i / kBitContainerSize;
|
|
uint32_t bit_in_element = i % kBitContainerSize;
|
|
|
|
if (element_index >= bits_.size()) {
|
|
return false;
|
|
}
|
|
|
|
BitContainer original = bits_[element_index];
|
|
BitContainer ith_bit = static_cast<BitContainer>(1) << bit_in_element;
|
|
|
|
if ((original & ith_bit) == 0) {
|
|
return false;
|
|
} else {
|
|
bits_[element_index] = original & (~ith_bit);
|
|
return true;
|
|
}
|
|
}
|
|
|
|
// Returns the |i|th bit.
|
|
bool Get(uint32_t i) const {
|
|
uint32_t element_index = i / kBitContainerSize;
|
|
uint32_t bit_in_element = i % kBitContainerSize;
|
|
|
|
if (element_index >= bits_.size()) {
|
|
return false;
|
|
}
|
|
|
|
return (bits_[element_index] &
|
|
(static_cast<BitContainer>(1) << bit_in_element)) != 0;
|
|
}
|
|
|
|
// Print a report on the densicy of the bit vector, number of 1 bits, number
|
|
// of bytes, and average bytes for 1 bit, to |out|.
|
|
void ReportDensity(std::ostream& out);
|
|
|
|
private:
|
|
std::vector<BitContainer> bits_;
|
|
};
|
|
|
|
} // namespace utils
|
|
} // namespace spvtools
|
|
|
|
#endif // LIBSPIRV_UTILS_BIT_VECTOR_H_
|