KOKO\Mimi
31 lines
861 B
C++
31 lines
861 B
C++
#ifndef FESA_MATH_COMPENSATED_SUM_H_
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#define FESA_MATH_COMPENSATED_SUM_H_
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#include <cmath>
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namespace fesa::math_internal {
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/// @brief Preserves the compensated scalar accumulation graph and caller order.
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inline void AddCompensated(const double term, double* sum, double* correction) {
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const double next = *sum + term;
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*correction += std::abs(*sum) >= std::abs(term)
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? (*sum - next) + term
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: (term - next) + *sum;
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*sum = next;
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}
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/// @brief Owns one sum and its correction without changing reduction order.
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class CompensatedSum {
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public:
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void Add(const double term) { AddCompensated(term, &sum_, &correction_); }
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double Value() const { return sum_ + correction_; }
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private:
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double sum_ = 0.0;
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double correction_ = 0.0;
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};
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} // namespace fesa::math_internal
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#endif // FESA_MATH_COMPENSATED_SUM_H_
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