mirror of
https://github.com/TomHarte/CLK.git
synced 2024-12-29 13:29:46 +00:00
299 lines
9.6 KiB
C++
299 lines
9.6 KiB
C++
//
|
|
// Storage.hpp
|
|
// Clock Signal
|
|
//
|
|
// Created by Thomas Harte on 10/07/2016.
|
|
// Copyright 2016 Thomas Harte. All rights reserved.
|
|
//
|
|
|
|
#ifndef Storage_hpp
|
|
#define Storage_hpp
|
|
|
|
#include <cmath>
|
|
#include <cstdint>
|
|
#include <limits>
|
|
#include <numeric>
|
|
|
|
namespace Storage {
|
|
|
|
/*!
|
|
Contains either an absolute time or a time interval, described as a quotient, in terms of a
|
|
clock rate to which the time is relative and its length in cycles based on that clock rate.
|
|
*/
|
|
struct Time {
|
|
unsigned int length, clock_rate;
|
|
constexpr Time() : length(0), clock_rate(1) {}
|
|
constexpr Time(unsigned int unsigned_int_value) : length(unsigned_int_value), clock_rate(1) {}
|
|
constexpr Time(int int_value) : Time(unsigned(int_value)) {}
|
|
constexpr Time(unsigned int length, unsigned int clock_rate) : length(length), clock_rate(clock_rate) {}
|
|
constexpr Time(int length, int clock_rate) : Time(unsigned(length), unsigned(clock_rate)) {}
|
|
Time(uint64_t length, uint64_t clock_rate) {
|
|
install_result(length, clock_rate);
|
|
}
|
|
Time(float value) {
|
|
install_float(value);
|
|
}
|
|
static constexpr Time simplified(unsigned int _length, unsigned int _clock_rate) {
|
|
const auto gcd = std::gcd(_length, _clock_rate);
|
|
return Time(_length / gcd, _clock_rate / gcd);
|
|
}
|
|
|
|
/*!
|
|
Reduces this @c Time to its simplest form; eliminates all common factors from @c length
|
|
and @c clock_rate.
|
|
*/
|
|
void simplify() {
|
|
unsigned int common_divisor = std::gcd(length, clock_rate);
|
|
length /= common_divisor;
|
|
clock_rate /= common_divisor;
|
|
}
|
|
|
|
/*!
|
|
@returns the floating point conversion of this @c Time. This will often be less precise.
|
|
*/
|
|
template <typename T> T get() const {
|
|
return T(length) / T(clock_rate);
|
|
}
|
|
|
|
inline bool operator < (const Time &other) const {
|
|
return uint64_t(other.clock_rate) * uint64_t(length) < uint64_t(clock_rate) * uint64_t(other.length);
|
|
}
|
|
|
|
inline bool operator <= (const Time &other) const {
|
|
return uint64_t(other.clock_rate) * uint64_t(length) <= uint64_t(clock_rate) * uint64_t(other.length);
|
|
}
|
|
|
|
inline bool operator > (const Time &other) const {
|
|
return uint64_t(other.clock_rate) * uint64_t(length) > uint64_t(clock_rate) * uint64_t(other.length);
|
|
}
|
|
|
|
inline bool operator >= (const Time &other) const {
|
|
return uint64_t(other.clock_rate) * uint64_t(length) >= uint64_t(clock_rate) * uint64_t(other.length);
|
|
}
|
|
|
|
inline bool operator == (const Time &other) const {
|
|
return uint64_t(other.clock_rate) * uint64_t(length) == uint64_t(clock_rate) * uint64_t(other.length);
|
|
}
|
|
|
|
inline Time operator + (const Time &other) const {
|
|
if(!other.length) return *this;
|
|
|
|
uint64_t result_length;
|
|
uint64_t result_clock_rate;
|
|
if(clock_rate == other.clock_rate) {
|
|
result_length = uint64_t(length) + uint64_t(other.length);
|
|
result_clock_rate = clock_rate;
|
|
} else {
|
|
result_length = uint64_t(length) * uint64_t(other.clock_rate) + uint64_t(other.length) * uint64_t(clock_rate);
|
|
result_clock_rate = uint64_t(clock_rate) * uint64_t(other.clock_rate);
|
|
}
|
|
return Time(result_length, result_clock_rate);
|
|
}
|
|
|
|
inline Time &operator += (const Time &other) {
|
|
if(!other.length) return *this;
|
|
if(!length) {
|
|
*this = other;
|
|
return *this;
|
|
}
|
|
|
|
uint64_t result_length;
|
|
uint64_t result_clock_rate;
|
|
if(clock_rate == other.clock_rate) {
|
|
result_length = uint64_t(length) + uint64_t(other.length);
|
|
result_clock_rate = uint64_t(clock_rate);
|
|
} else {
|
|
result_length = uint64_t(length) * uint64_t(other.clock_rate) + uint64_t(other.length) * uint64_t(clock_rate);
|
|
result_clock_rate = uint64_t(clock_rate) * uint64_t(other.clock_rate);
|
|
}
|
|
install_result(result_length, result_clock_rate);
|
|
return *this;
|
|
}
|
|
|
|
inline Time operator - (const Time &other) const {
|
|
if(!other.length) return *this;
|
|
|
|
uint64_t result_length;
|
|
uint64_t result_clock_rate;
|
|
if(clock_rate == other.clock_rate) {
|
|
result_length = uint64_t(length) - uint64_t(other.length);
|
|
result_clock_rate = clock_rate;
|
|
} else {
|
|
result_length = uint64_t(length) * uint64_t(other.clock_rate) - uint64_t(other.length) * uint64_t(clock_rate);
|
|
result_clock_rate = uint64_t(clock_rate) * uint64_t(other.clock_rate);
|
|
}
|
|
return Time(result_length, result_clock_rate);
|
|
}
|
|
|
|
inline Time operator -= (const Time &other) {
|
|
if(!other.length) return *this;
|
|
|
|
uint64_t result_length;
|
|
uint64_t result_clock_rate;
|
|
if(clock_rate == other.clock_rate) {
|
|
result_length = uint64_t(length) - uint64_t(other.length);
|
|
result_clock_rate = uint64_t(clock_rate);
|
|
} else {
|
|
result_length = uint64_t(length) * uint64_t(other.clock_rate) - uint64_t(other.length) * uint64_t(clock_rate);
|
|
result_clock_rate = uint64_t(clock_rate) * uint64_t(other.clock_rate);
|
|
}
|
|
install_result(result_length, result_clock_rate);
|
|
return *this;
|
|
}
|
|
|
|
inline Time operator * (const Time &other) const {
|
|
uint64_t result_length = uint64_t(length) * uint64_t(other.length);
|
|
uint64_t result_clock_rate = uint64_t(clock_rate) * uint64_t(other.clock_rate);
|
|
return Time(result_length, result_clock_rate);
|
|
}
|
|
|
|
inline Time &operator *= (const Time &other) {
|
|
uint64_t result_length = uint64_t(length) * uint64_t(other.length);
|
|
uint64_t result_clock_rate = uint64_t(clock_rate) * uint64_t(other.clock_rate);
|
|
install_result(result_length, result_clock_rate);
|
|
return *this;
|
|
}
|
|
|
|
inline Time operator * (unsigned int multiplier) const {
|
|
uint64_t result_length = uint64_t(length) * uint64_t(multiplier);
|
|
uint64_t result_clock_rate = uint64_t(clock_rate);
|
|
return Time(result_length, result_clock_rate);
|
|
}
|
|
|
|
inline Time &operator *= (unsigned int multiplier) {
|
|
uint64_t result_length = uint64_t(length) * uint64_t(multiplier);
|
|
uint64_t result_clock_rate = uint64_t(clock_rate);
|
|
install_result(result_length, result_clock_rate);
|
|
return *this;
|
|
}
|
|
|
|
inline Time operator / (const Time &other) const {
|
|
uint64_t result_length = uint64_t(length) * uint64_t(other.clock_rate);
|
|
uint64_t result_clock_rate = uint64_t(clock_rate) * uint64_t(other.length);
|
|
return Time(result_length, result_clock_rate);
|
|
}
|
|
|
|
inline Time &operator /= (const Time &other) {
|
|
uint64_t result_length = uint64_t(length) * uint64_t(other.clock_rate);
|
|
uint64_t result_clock_rate = uint64_t(clock_rate) * uint64_t(other.length);
|
|
install_result(result_length, result_clock_rate);
|
|
return *this;
|
|
}
|
|
|
|
inline Time operator / (unsigned int divisor) const {
|
|
uint64_t result_length = uint64_t(length);
|
|
uint64_t result_clock_rate = uint64_t(clock_rate) * uint64_t(divisor);
|
|
return Time(result_length, result_clock_rate);
|
|
}
|
|
|
|
inline Time &operator /= (unsigned int divisor) {
|
|
uint64_t result_length = uint64_t(length);
|
|
uint64_t result_clock_rate = uint64_t(clock_rate) * uint64_t(divisor);
|
|
install_result(result_length, result_clock_rate);
|
|
return *this;
|
|
}
|
|
|
|
inline void set_zero() {
|
|
length = 0;
|
|
clock_rate = 1;
|
|
}
|
|
|
|
inline void set_one() {
|
|
length = 1;
|
|
clock_rate = 1;
|
|
}
|
|
|
|
static Time max() {
|
|
return Time(std::numeric_limits<unsigned int>::max());
|
|
}
|
|
|
|
private:
|
|
inline void install_result(uint64_t long_length, uint64_t long_clock_rate) {
|
|
if(long_length <= std::numeric_limits<unsigned int>::max() && long_clock_rate <= std::numeric_limits<unsigned int>::max()) {
|
|
length = unsigned(long_length);
|
|
clock_rate = unsigned(long_clock_rate);
|
|
return;
|
|
}
|
|
|
|
// TODO: switch to appropriate values if the result is too large or small to fit, even with trimmed accuracy.
|
|
if(!long_length) {
|
|
length = 0;
|
|
clock_rate = 1;
|
|
return;
|
|
}
|
|
|
|
while(!(long_length&0xf) && !(long_clock_rate&0xf)) {
|
|
long_length >>= 4;
|
|
long_clock_rate >>= 4;
|
|
}
|
|
|
|
while(!(long_length&1) && !(long_clock_rate&1)) {
|
|
long_length >>= 1;
|
|
long_clock_rate >>= 1;
|
|
}
|
|
|
|
if(long_length > std::numeric_limits<unsigned int>::max() || long_clock_rate > std::numeric_limits<unsigned int>::max()) {
|
|
uint64_t common_divisor = std::gcd(long_length, long_clock_rate);
|
|
long_length /= common_divisor;
|
|
long_clock_rate /= common_divisor;
|
|
|
|
// Okay, in desperation accept a loss of accuracy.
|
|
while(
|
|
(long_length > std::numeric_limits<unsigned int>::max() || long_clock_rate > std::numeric_limits<unsigned int>::max()) &&
|
|
(long_clock_rate > 1)) {
|
|
long_length >>= 1;
|
|
long_clock_rate >>= 1;
|
|
}
|
|
}
|
|
|
|
if(long_length <= std::numeric_limits<unsigned int>::max() && long_clock_rate <= std::numeric_limits<unsigned int>::max()) {
|
|
length = unsigned(long_length);
|
|
clock_rate = unsigned(long_clock_rate);
|
|
} else {
|
|
length = std::numeric_limits<unsigned int>::max();
|
|
clock_rate = 1u;
|
|
}
|
|
}
|
|
|
|
inline void install_float(float value) {
|
|
// Grab the float's native mantissa and exponent.
|
|
int exponent;
|
|
const float mantissa = frexpf(value, &exponent);
|
|
|
|
// Turn the mantissa into an int, and adjust the exponent
|
|
// appropriately.
|
|
const uint64_t loaded_mantissa = uint64_t(ldexpf(mantissa, 24));
|
|
const auto relative_exponent = exponent - 24;
|
|
|
|
// If the mantissa is negative and its absolute value fits within a 64-bit integer,
|
|
// just load up.
|
|
if(relative_exponent <= 0 && relative_exponent > -64) {
|
|
install_result(loaded_mantissa, uint64_t(1) << -relative_exponent);
|
|
return;
|
|
}
|
|
|
|
// If the exponent is positive but doesn't cause loaded_mantissa to overflow,
|
|
// install with the natural encoding.
|
|
if(relative_exponent > 0 && relative_exponent < (64 - 24)) {
|
|
install_result(loaded_mantissa << relative_exponent, 1);
|
|
return;
|
|
}
|
|
|
|
// Otherwise, if this number is too large to store, store the maximum value.
|
|
if(relative_exponent > 0) {
|
|
install_result(std::numeric_limits<uint64_t>::max(), 1);
|
|
return;
|
|
}
|
|
|
|
// If the number is too small to store accurately, store 0.
|
|
if(relative_exponent < 0) {
|
|
install_result(0, 1);
|
|
return;
|
|
}
|
|
}
|
|
};
|
|
|
|
}
|
|
|
|
#endif /* Storage_h */
|