/*
* nextpnr -- Next Generation Place and Route
*
* Copyright (C) 2021 Symbiflow Authors
*
* Permission to use, copy, modify, and/or distribute this software for any
* purpose with or without fee is hereby granted, provided that the above
* copyright notice and this permission notice appear in all copies.
*
* THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
* WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
* MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
* ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
* WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
* ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
* OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
*
*/
#ifndef DYNAMIC_BITARRAY_H
#define DYNAMIC_BITARRAY_H
#include <cstdint>
#include <limits>
#include <vector>
#include "log.h"
#include "nextpnr_assertions.h"
#include "nextpnr_namespaces.h"
NEXTPNR_NAMESPACE_BEGIN
// This class implements a simple dynamic bitarray, backed by some resizable
// random access storage. The default is to use a std::vector<uint8_t>.
template <typename Storage = std::vector<uint8_t>> class DynamicBitarray
{
public:
static_assert(!std::numeric_limits<typename Storage::value_type>::is_signed, "Storage must be unsigned!");
void fill(bool value)
{
std::fill(storage.begin(), storage.end(), value ? std::numeric_limits<typename Storage::value_type>::max() : 0);
}
constexpr size_t bits_per_value() const { return std::numeric_limits<typename Storage::value_type>::digits; }
bool get(size_t bit) const
{
size_t element_index = bit / bits_per_value();
size_t bit_offset = bit % bits_per_value();
auto element = storage.at(element_index);
return (element & (1 << bit_offset)) != 0;
}
void set(size_t bit, bool value)
{
size_t element_index = bit / bits_per_value();
size_t bit_offset = bit % bits_per_value();
if (value) {
storage.at(element_index) |= (1 << bit_offset);
} else {
storage.at(element_index) &= ~(1 << bit_offset);
}
}
void resize(size_t number_bits)
{
size_t required_storage = (number_bits + bits_per_value() - 1) / bits_per_value();
storage.resize(required_storage);
}
size_t size() const { return storage.size() * bits_per_value(); }
void clear() { return storage.clear(); }
// Convert IntType to a DynamicBitarray of sufficent width
template <typename IntType> static DynamicBitarray<Storage> to_bitarray(const IntType &value)
{
if (std::numeric_limits<IntType>::is_signed) {
if (value < 0) {
log_error("Expected position value, got %s\n", std::to_string(value).c_str());
}
}
DynamicBitarray<Storage> result;
result.resize(std::numeric_limits<IntType>::digits);
result.fill(false);
// Use a 1 of the right type (for shifting)
IntType one(1);
for (size_t i = 0; i < std::numeric_limits<IntType>::digits; ++i) {
if ((value & (one << i)) != 0) {
result.set(i, true);
}
}
return result;
}
// Convert binary bitstring to a DynamicBitarray of sufficent width
//
// string must be satisfy the following regex:
//
// [01]+
//
// width can either be specified explicitly, or -1 to use a size wide
// enough to store the given string.
//
// If the width is specified and the width is insufficent it will result
// in an error.
static DynamicBitarray<Storage> parse_binary_bitstring(int width, const std::string &bits)
{
NPNR_ASSERT(width == -1 || width > 0);
DynamicBitarray<Storage> result;
// If no width was supplied, use the width from the input data.
if (width == -1) {
width = bits.size();
}
NPNR_ASSERT(width >= 0);
if ((size_t)width < bits.size()) {
log_error("String '%s' is wider than specified width %d\n", bits.c_str(), width);
}
result.resize(width);
result.fill(false);
for (size_t i = 0; i < bits.size(); ++i) {
// bits[0] is the MSB!
size_t index = width - 1 - i;
if (!(bits[i] == '1' || bits[i] == '0')) {
log_error("String '%s' is not a valid binary bitstring?\n", bits.c_str());
}
result.set(index, bits[i] == '1');
}
return result;
}
// Convert hex bitstring to a DynamicBitarray of sufficent width
//
// string must be satisfy the following regex:
//
// [0-9a-fA-F]+
//
// width can either be specified explicitly, or -1 to use a size wide
// enough to store the given string.
//
// If the width is specified and the width is insufficent it will result
// in an error.
static DynamicBitarray<Storage> parse_hex_bitstring(int width, const std::string &bits)
{
NPNR_ASSERT(width == -1 || width > 0);
DynamicBitarray<Storage> result;
// If no width was supplied, use the width from the input data.
if (width == -1) {
// Each character is 4 bits!
width = bits.size() * 4;
}
NPNR_ASSERT(width >= 0);
int rem = width % 4;
size_t check_width = width;
if (rem != 0) {
check_width += (4 - rem);
}
if (check_width < bits.size() * 4) {
log_error("String '%s' is wider than specified width %d (check_width = %zu)\n", bits.c_str(), width,
check_width);
}
result.resize(width);
result.fill(false);
size_t index = 0;
for (auto nibble_iter = bits.rbegin(); nibble_iter != bits.rend(); ++nibble_iter) {
char nibble = *nibble_iter;
int value;
if (nibble >= '0' && nibble <= '9') {
value = nibble - '0';
} else if (nibble >= 'a' && nibble <= 'f') {
value = 10 + (nibble - 'a');
} else if (nibble >= 'A' && nibble <= 'F') {
value = 10 + (nibble - 'A');
} else {
log_error("Invalid hex string '%s'?\n", bits.c_str());
}
NPNR_ASSERT(value >= 0);
NPNR_ASSERT(value < 16);
// Insert nibble into bitarray.
for (size_t i = 0; i < 4; ++i) {
result.set(index++, (value & (1 << i)) != 0);
}
}
return result;
}
private:
Storage storage;
};
NEXTPNR_NAMESPACE_END
#endif /* DYNAMIC_BITARRAY_H */