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Attempts better to deal with large numbers.

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This commit is contained in:
Thomas Harte 2017-12-20 21:03:24 -05:00
parent 0bb24075b6
commit f17758e7f9
1 changed files with 16 additions and 5 deletions
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21
Storage/TimedEventLoop.cpp
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@ -65,18 +65,29 @@ void TimedEventLoop::jump_to_next_event() {
void TimedEventLoop::set_next_event_time_interval(Time interval) {
// Calculate [interval]*[input clock rate] + [subcycles until this event].
int64_t denominator = (int64_t)interval.clock_rate * (int64_t)subcycles_until_event_.clock_rate;
int64_t denominator = static_cast<int64_t>(interval.clock_rate) * static_cast<int64_t>(subcycles_until_event_.clock_rate);
int64_t numerator =
(int64_t)subcycles_until_event_.clock_rate * (int64_t)input_clock_rate_ * (int64_t)interval.length +
(int64_t)interval.clock_rate * (int64_t)subcycles_until_event_.length;
static_cast<int64_t>(subcycles_until_event_.clock_rate) * static_cast<int64_t>(input_clock_rate_) * static_cast<int64_t>(interval.length) +
static_cast<int64_t>(interval.clock_rate) * static_cast<int64_t>(subcycles_until_event_.length);
// Simplify if necessary.
if(denominator > std::numeric_limits<unsigned int>::max()) {
// Simplify if necessary: try just simplifying the interval and recalculating; if that doesn't
// work then try simplifying the whole thing.
if(numerator < 0 || denominator < 0 || denominator > std::numeric_limits<unsigned int>::max()) {
interval.simplify();
denominator = static_cast<int64_t>(interval.clock_rate) * static_cast<int64_t>(subcycles_until_event_.clock_rate);
numerator =
static_cast<int64_t>(subcycles_until_event_.clock_rate) * static_cast<int64_t>(input_clock_rate_) * static_cast<int64_t>(interval.length) +
static_cast<int64_t>(interval.clock_rate) * static_cast<int64_t>(subcycles_until_event_.length);
}
if(numerator < 0 || denominator < 0 || denominator > std::numeric_limits<unsigned int>::max()) {
int64_t common_divisor = NumberTheory::greatest_common_divisor(numerator % denominator, denominator);
denominator /= common_divisor;
numerator /= common_divisor;
}
// TODO: if that doesn't work then reduce precision.
// So this event will fire in the integral number of cycles from now, putting us at the remainder
// number of subcycles
assert(cycles_until_event_ == 0);