Maksimov and Kolovsky, Equation (32)

Percentage Accurate: 76.0% → 96.5%
Time: 9.0s
Alternatives: 6
Speedup: 1.6×

Specification

?
\[\begin{array}{l} \\ \cos \left(\frac{K \cdot \left(m + n\right)}{2} - M\right) \cdot e^{\left(-{\left(\frac{m + n}{2} - M\right)}^{2}\right) - \left(\ell - \left|m - n\right|\right)} \end{array} \]
(FPCore (K m n M l)
 :precision binary64
 (*
  (cos (- (/ (* K (+ m n)) 2.0) M))
  (exp (- (- (pow (- (/ (+ m n) 2.0) M) 2.0)) (- l (fabs (- m n)))))))
double code(double K, double m, double n, double M, double l) {
	return cos((((K * (m + n)) / 2.0) - M)) * exp((-pow((((m + n) / 2.0) - M), 2.0) - (l - fabs((m - n)))));
}
real(8) function code(k, m, n, m_1, l)
    real(8), intent (in) :: k
    real(8), intent (in) :: m
    real(8), intent (in) :: n
    real(8), intent (in) :: m_1
    real(8), intent (in) :: l
    code = cos((((k * (m + n)) / 2.0d0) - m_1)) * exp((-((((m + n) / 2.0d0) - m_1) ** 2.0d0) - (l - abs((m - n)))))
end function
public static double code(double K, double m, double n, double M, double l) {
	return Math.cos((((K * (m + n)) / 2.0) - M)) * Math.exp((-Math.pow((((m + n) / 2.0) - M), 2.0) - (l - Math.abs((m - n)))));
}
def code(K, m, n, M, l):
	return math.cos((((K * (m + n)) / 2.0) - M)) * math.exp((-math.pow((((m + n) / 2.0) - M), 2.0) - (l - math.fabs((m - n)))))
function code(K, m, n, M, l)
	return Float64(cos(Float64(Float64(Float64(K * Float64(m + n)) / 2.0) - M)) * exp(Float64(Float64(-(Float64(Float64(Float64(m + n) / 2.0) - M) ^ 2.0)) - Float64(l - abs(Float64(m - n))))))
end
function tmp = code(K, m, n, M, l)
	tmp = cos((((K * (m + n)) / 2.0) - M)) * exp((-((((m + n) / 2.0) - M) ^ 2.0) - (l - abs((m - n)))));
end
code[K_, m_, n_, M_, l_] := N[(N[Cos[N[(N[(N[(K * N[(m + n), $MachinePrecision]), $MachinePrecision] / 2.0), $MachinePrecision] - M), $MachinePrecision]], $MachinePrecision] * N[Exp[N[((-N[Power[N[(N[(N[(m + n), $MachinePrecision] / 2.0), $MachinePrecision] - M), $MachinePrecision], 2.0], $MachinePrecision]) - N[(l - N[Abs[N[(m - n), $MachinePrecision]], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]], $MachinePrecision]), $MachinePrecision]
\begin{array}{l}

\\
\cos \left(\frac{K \cdot \left(m + n\right)}{2} - M\right) \cdot e^{\left(-{\left(\frac{m + n}{2} - M\right)}^{2}\right) - \left(\ell - \left|m - n\right|\right)}
\end{array}

Sampling outcomes in binary64 precision:

Local Percentage Accuracy vs ?

The average percentage accuracy by input value. Horizontal axis shows value of an input variable; the variable is choosen in the title. Vertical axis is accuracy; higher is better. Red represent the original program, while blue represents Herbie's suggestion. These can be toggled with buttons below the plot. The line is an average while dots represent individual samples.

Accuracy vs Speed?

Herbie found 6 alternatives:

AlternativeAccuracySpeedup
The accuracy (vertical axis) and speed (horizontal axis) of each alternatives. Up and to the right is better. The red square shows the initial program, and each blue circle shows an alternative.The line shows the best available speed-accuracy tradeoffs.

Initial Program: 76.0% accurate, 1.0× speedup?

\[\begin{array}{l} \\ \cos \left(\frac{K \cdot \left(m + n\right)}{2} - M\right) \cdot e^{\left(-{\left(\frac{m + n}{2} - M\right)}^{2}\right) - \left(\ell - \left|m - n\right|\right)} \end{array} \]
(FPCore (K m n M l)
 :precision binary64
 (*
  (cos (- (/ (* K (+ m n)) 2.0) M))
  (exp (- (- (pow (- (/ (+ m n) 2.0) M) 2.0)) (- l (fabs (- m n)))))))
double code(double K, double m, double n, double M, double l) {
	return cos((((K * (m + n)) / 2.0) - M)) * exp((-pow((((m + n) / 2.0) - M), 2.0) - (l - fabs((m - n)))));
}
real(8) function code(k, m, n, m_1, l)
    real(8), intent (in) :: k
    real(8), intent (in) :: m
    real(8), intent (in) :: n
    real(8), intent (in) :: m_1
    real(8), intent (in) :: l
    code = cos((((k * (m + n)) / 2.0d0) - m_1)) * exp((-((((m + n) / 2.0d0) - m_1) ** 2.0d0) - (l - abs((m - n)))))
end function
public static double code(double K, double m, double n, double M, double l) {
	return Math.cos((((K * (m + n)) / 2.0) - M)) * Math.exp((-Math.pow((((m + n) / 2.0) - M), 2.0) - (l - Math.abs((m - n)))));
}
def code(K, m, n, M, l):
	return math.cos((((K * (m + n)) / 2.0) - M)) * math.exp((-math.pow((((m + n) / 2.0) - M), 2.0) - (l - math.fabs((m - n)))))
function code(K, m, n, M, l)
	return Float64(cos(Float64(Float64(Float64(K * Float64(m + n)) / 2.0) - M)) * exp(Float64(Float64(-(Float64(Float64(Float64(m + n) / 2.0) - M) ^ 2.0)) - Float64(l - abs(Float64(m - n))))))
end
function tmp = code(K, m, n, M, l)
	tmp = cos((((K * (m + n)) / 2.0) - M)) * exp((-((((m + n) / 2.0) - M) ^ 2.0) - (l - abs((m - n)))));
end
code[K_, m_, n_, M_, l_] := N[(N[Cos[N[(N[(N[(K * N[(m + n), $MachinePrecision]), $MachinePrecision] / 2.0), $MachinePrecision] - M), $MachinePrecision]], $MachinePrecision] * N[Exp[N[((-N[Power[N[(N[(N[(m + n), $MachinePrecision] / 2.0), $MachinePrecision] - M), $MachinePrecision], 2.0], $MachinePrecision]) - N[(l - N[Abs[N[(m - n), $MachinePrecision]], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]], $MachinePrecision]), $MachinePrecision]
\begin{array}{l}

\\
\cos \left(\frac{K \cdot \left(m + n\right)}{2} - M\right) \cdot e^{\left(-{\left(\frac{m + n}{2} - M\right)}^{2}\right) - \left(\ell - \left|m - n\right|\right)}
\end{array}

Alternative 1: 96.5% accurate, 1.1× speedup?

\[\begin{array}{l} \\ \cos M \cdot e^{\left|n - m\right| - \left({\left(\mathsf{fma}\left(0.5, n + m, -M\right)\right)}^{2} + \ell\right)} \end{array} \]
(FPCore (K m n M l)
 :precision binary64
 (* (cos M) (exp (- (fabs (- n m)) (+ (pow (fma 0.5 (+ n m) (- M)) 2.0) l)))))
double code(double K, double m, double n, double M, double l) {
	return cos(M) * exp((fabs((n - m)) - (pow(fma(0.5, (n + m), -M), 2.0) + l)));
}
function code(K, m, n, M, l)
	return Float64(cos(M) * exp(Float64(abs(Float64(n - m)) - Float64((fma(0.5, Float64(n + m), Float64(-M)) ^ 2.0) + l))))
end
code[K_, m_, n_, M_, l_] := N[(N[Cos[M], $MachinePrecision] * N[Exp[N[(N[Abs[N[(n - m), $MachinePrecision]], $MachinePrecision] - N[(N[Power[N[(0.5 * N[(n + m), $MachinePrecision] + (-M)), $MachinePrecision], 2.0], $MachinePrecision] + l), $MachinePrecision]), $MachinePrecision]], $MachinePrecision]), $MachinePrecision]
\begin{array}{l}

\\
\cos M \cdot e^{\left|n - m\right| - \left({\left(\mathsf{fma}\left(0.5, n + m, -M\right)\right)}^{2} + \ell\right)}
\end{array}
Derivation
  1. Initial program 78.7%

    \[\cos \left(\frac{K \cdot \left(m + n\right)}{2} - M\right) \cdot e^{\left(-{\left(\frac{m + n}{2} - M\right)}^{2}\right) - \left(\ell - \left|m - n\right|\right)} \]
  2. Add Preprocessing
  3. Taylor expanded in K around 0

    \[\leadsto \color{blue}{\cos \left(\mathsf{neg}\left(M\right)\right) \cdot e^{\left|m - n\right| - \left(\ell + {\left(\frac{1}{2} \cdot \left(m + n\right) - M\right)}^{2}\right)}} \]
  4. Step-by-step derivation
    1. *-commutativeN/A

      \[\leadsto \color{blue}{e^{\left|m - n\right| - \left(\ell + {\left(\frac{1}{2} \cdot \left(m + n\right) - M\right)}^{2}\right)} \cdot \cos \left(\mathsf{neg}\left(M\right)\right)} \]
    2. lower-*.f64N/A

      \[\leadsto \color{blue}{e^{\left|m - n\right| - \left(\ell + {\left(\frac{1}{2} \cdot \left(m + n\right) - M\right)}^{2}\right)} \cdot \cos \left(\mathsf{neg}\left(M\right)\right)} \]
  5. Applied rewrites98.5%

    \[\leadsto \color{blue}{e^{\left|m - n\right| - \left({\left(\mathsf{fma}\left(0.5, n + m, -M\right)\right)}^{2} + \ell\right)} \cdot \cos M} \]
  6. Final simplification98.5%

    \[\leadsto \cos M \cdot e^{\left|n - m\right| - \left({\left(\mathsf{fma}\left(0.5, n + m, -M\right)\right)}^{2} + \ell\right)} \]
  7. Add Preprocessing

Alternative 2: 94.5% accurate, 1.6× speedup?

\[\begin{array}{l} \\ \begin{array}{l} t_0 := e^{\left(-M\right) \cdot M} \cdot \cos M\\ \mathbf{if}\;M \leq -2.6 \cdot 10^{+28}:\\ \;\;\;\;t\_0\\ \mathbf{elif}\;M \leq 7.6 \cdot 10^{+86}:\\ \;\;\;\;e^{\left|n - m\right| - \mathsf{fma}\left(0.25, {\left(n + m\right)}^{2}, \ell\right)}\\ \mathbf{else}:\\ \;\;\;\;t\_0\\ \end{array} \end{array} \]
(FPCore (K m n M l)
 :precision binary64
 (let* ((t_0 (* (exp (* (- M) M)) (cos M))))
   (if (<= M -2.6e+28)
     t_0
     (if (<= M 7.6e+86)
       (exp (- (fabs (- n m)) (fma 0.25 (pow (+ n m) 2.0) l)))
       t_0))))
double code(double K, double m, double n, double M, double l) {
	double t_0 = exp((-M * M)) * cos(M);
	double tmp;
	if (M <= -2.6e+28) {
		tmp = t_0;
	} else if (M <= 7.6e+86) {
		tmp = exp((fabs((n - m)) - fma(0.25, pow((n + m), 2.0), l)));
	} else {
		tmp = t_0;
	}
	return tmp;
}
function code(K, m, n, M, l)
	t_0 = Float64(exp(Float64(Float64(-M) * M)) * cos(M))
	tmp = 0.0
	if (M <= -2.6e+28)
		tmp = t_0;
	elseif (M <= 7.6e+86)
		tmp = exp(Float64(abs(Float64(n - m)) - fma(0.25, (Float64(n + m) ^ 2.0), l)));
	else
		tmp = t_0;
	end
	return tmp
end
code[K_, m_, n_, M_, l_] := Block[{t$95$0 = N[(N[Exp[N[((-M) * M), $MachinePrecision]], $MachinePrecision] * N[Cos[M], $MachinePrecision]), $MachinePrecision]}, If[LessEqual[M, -2.6e+28], t$95$0, If[LessEqual[M, 7.6e+86], N[Exp[N[(N[Abs[N[(n - m), $MachinePrecision]], $MachinePrecision] - N[(0.25 * N[Power[N[(n + m), $MachinePrecision], 2.0], $MachinePrecision] + l), $MachinePrecision]), $MachinePrecision]], $MachinePrecision], t$95$0]]]
\begin{array}{l}

\\
\begin{array}{l}
t_0 := e^{\left(-M\right) \cdot M} \cdot \cos M\\
\mathbf{if}\;M \leq -2.6 \cdot 10^{+28}:\\
\;\;\;\;t\_0\\

\mathbf{elif}\;M \leq 7.6 \cdot 10^{+86}:\\
\;\;\;\;e^{\left|n - m\right| - \mathsf{fma}\left(0.25, {\left(n + m\right)}^{2}, \ell\right)}\\

\mathbf{else}:\\
\;\;\;\;t\_0\\


\end{array}
\end{array}
Derivation
  1. Split input into 2 regimes
  2. if M < -2.6000000000000002e28 or 7.59999999999999956e86 < M

    1. Initial program 77.5%

      \[\cos \left(\frac{K \cdot \left(m + n\right)}{2} - M\right) \cdot e^{\left(-{\left(\frac{m + n}{2} - M\right)}^{2}\right) - \left(\ell - \left|m - n\right|\right)} \]
    2. Add Preprocessing
    3. Taylor expanded in K around 0

      \[\leadsto \color{blue}{\cos \left(\mathsf{neg}\left(M\right)\right) \cdot e^{\left|m - n\right| - \left(\ell + {\left(\frac{1}{2} \cdot \left(m + n\right) - M\right)}^{2}\right)}} \]
    4. Step-by-step derivation
      1. *-commutativeN/A

        \[\leadsto \color{blue}{e^{\left|m - n\right| - \left(\ell + {\left(\frac{1}{2} \cdot \left(m + n\right) - M\right)}^{2}\right)} \cdot \cos \left(\mathsf{neg}\left(M\right)\right)} \]
      2. lower-*.f64N/A

        \[\leadsto \color{blue}{e^{\left|m - n\right| - \left(\ell + {\left(\frac{1}{2} \cdot \left(m + n\right) - M\right)}^{2}\right)} \cdot \cos \left(\mathsf{neg}\left(M\right)\right)} \]
    5. Applied rewrites100.0%

      \[\leadsto \color{blue}{e^{\left|m - n\right| - \left({\left(\mathsf{fma}\left(0.5, n + m, -M\right)\right)}^{2} + \ell\right)} \cdot \cos M} \]
    6. Taylor expanded in M around inf

      \[\leadsto e^{-1 \cdot {M}^{2}} \cdot \cos M \]
    7. Step-by-step derivation
      1. Applied rewrites99.0%

        \[\leadsto e^{\left(-M\right) \cdot M} \cdot \cos M \]

      if -2.6000000000000002e28 < M < 7.59999999999999956e86

      1. Initial program 79.5%

        \[\cos \left(\frac{K \cdot \left(m + n\right)}{2} - M\right) \cdot e^{\left(-{\left(\frac{m + n}{2} - M\right)}^{2}\right) - \left(\ell - \left|m - n\right|\right)} \]
      2. Add Preprocessing
      3. Taylor expanded in K around 0

        \[\leadsto \color{blue}{\cos \left(\mathsf{neg}\left(M\right)\right) \cdot e^{\left|m - n\right| - \left(\ell + {\left(\frac{1}{2} \cdot \left(m + n\right) - M\right)}^{2}\right)}} \]
      4. Step-by-step derivation
        1. *-commutativeN/A

          \[\leadsto \color{blue}{e^{\left|m - n\right| - \left(\ell + {\left(\frac{1}{2} \cdot \left(m + n\right) - M\right)}^{2}\right)} \cdot \cos \left(\mathsf{neg}\left(M\right)\right)} \]
        2. lower-*.f64N/A

          \[\leadsto \color{blue}{e^{\left|m - n\right| - \left(\ell + {\left(\frac{1}{2} \cdot \left(m + n\right) - M\right)}^{2}\right)} \cdot \cos \left(\mathsf{neg}\left(M\right)\right)} \]
      5. Applied rewrites97.4%

        \[\leadsto \color{blue}{e^{\left|m - n\right| - \left({\left(\mathsf{fma}\left(0.5, n + m, -M\right)\right)}^{2} + \ell\right)} \cdot \cos M} \]
      6. Taylor expanded in M around 0

        \[\leadsto e^{\left|m - n\right| - \left(\ell + \frac{1}{4} \cdot {\left(m + n\right)}^{2}\right)} \]
      7. Step-by-step derivation
        1. Applied rewrites96.3%

          \[\leadsto e^{\left|m - n\right| - \mathsf{fma}\left(0.25, {\left(n + m\right)}^{2}, \ell\right)} \]
      8. Recombined 2 regimes into one program.
      9. Final simplification97.4%

        \[\leadsto \begin{array}{l} \mathbf{if}\;M \leq -2.6 \cdot 10^{+28}:\\ \;\;\;\;e^{\left(-M\right) \cdot M} \cdot \cos M\\ \mathbf{elif}\;M \leq 7.6 \cdot 10^{+86}:\\ \;\;\;\;e^{\left|n - m\right| - \mathsf{fma}\left(0.25, {\left(n + m\right)}^{2}, \ell\right)}\\ \mathbf{else}:\\ \;\;\;\;e^{\left(-M\right) \cdot M} \cdot \cos M\\ \end{array} \]
      10. Add Preprocessing

      Alternative 3: 73.6% accurate, 2.8× speedup?

      \[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;m \leq -54:\\ \;\;\;\;e^{-0.25 \cdot \left(m \cdot m\right)}\\ \mathbf{else}:\\ \;\;\;\;e^{\left|n - m\right| - \mathsf{fma}\left(0.25, n \cdot n, \ell\right)}\\ \end{array} \end{array} \]
      (FPCore (K m n M l)
       :precision binary64
       (if (<= m -54.0)
         (exp (* -0.25 (* m m)))
         (exp (- (fabs (- n m)) (fma 0.25 (* n n) l)))))
      double code(double K, double m, double n, double M, double l) {
      	double tmp;
      	if (m <= -54.0) {
      		tmp = exp((-0.25 * (m * m)));
      	} else {
      		tmp = exp((fabs((n - m)) - fma(0.25, (n * n), l)));
      	}
      	return tmp;
      }
      
      function code(K, m, n, M, l)
      	tmp = 0.0
      	if (m <= -54.0)
      		tmp = exp(Float64(-0.25 * Float64(m * m)));
      	else
      		tmp = exp(Float64(abs(Float64(n - m)) - fma(0.25, Float64(n * n), l)));
      	end
      	return tmp
      end
      
      code[K_, m_, n_, M_, l_] := If[LessEqual[m, -54.0], N[Exp[N[(-0.25 * N[(m * m), $MachinePrecision]), $MachinePrecision]], $MachinePrecision], N[Exp[N[(N[Abs[N[(n - m), $MachinePrecision]], $MachinePrecision] - N[(0.25 * N[(n * n), $MachinePrecision] + l), $MachinePrecision]), $MachinePrecision]], $MachinePrecision]]
      
      \begin{array}{l}
      
      \\
      \begin{array}{l}
      \mathbf{if}\;m \leq -54:\\
      \;\;\;\;e^{-0.25 \cdot \left(m \cdot m\right)}\\
      
      \mathbf{else}:\\
      \;\;\;\;e^{\left|n - m\right| - \mathsf{fma}\left(0.25, n \cdot n, \ell\right)}\\
      
      
      \end{array}
      \end{array}
      
      Derivation
      1. Split input into 2 regimes
      2. if m < -54

        1. Initial program 75.8%

          \[\cos \left(\frac{K \cdot \left(m + n\right)}{2} - M\right) \cdot e^{\left(-{\left(\frac{m + n}{2} - M\right)}^{2}\right) - \left(\ell - \left|m - n\right|\right)} \]
        2. Add Preprocessing
        3. Taylor expanded in K around 0

          \[\leadsto \color{blue}{\cos \left(\mathsf{neg}\left(M\right)\right) \cdot e^{\left|m - n\right| - \left(\ell + {\left(\frac{1}{2} \cdot \left(m + n\right) - M\right)}^{2}\right)}} \]
        4. Step-by-step derivation
          1. *-commutativeN/A

            \[\leadsto \color{blue}{e^{\left|m - n\right| - \left(\ell + {\left(\frac{1}{2} \cdot \left(m + n\right) - M\right)}^{2}\right)} \cdot \cos \left(\mathsf{neg}\left(M\right)\right)} \]
          2. lower-*.f64N/A

            \[\leadsto \color{blue}{e^{\left|m - n\right| - \left(\ell + {\left(\frac{1}{2} \cdot \left(m + n\right) - M\right)}^{2}\right)} \cdot \cos \left(\mathsf{neg}\left(M\right)\right)} \]
        5. Applied rewrites100.0%

          \[\leadsto \color{blue}{e^{\left|m - n\right| - \left({\left(\mathsf{fma}\left(0.5, n + m, -M\right)\right)}^{2} + \ell\right)} \cdot \cos M} \]
        6. Taylor expanded in M around 0

          \[\leadsto e^{\left|m - n\right| - \left(\ell + \frac{1}{4} \cdot {\left(m + n\right)}^{2}\right)} \]
        7. Step-by-step derivation
          1. Applied rewrites100.0%

            \[\leadsto e^{\left|m - n\right| - \mathsf{fma}\left(0.25, {\left(n + m\right)}^{2}, \ell\right)} \]
          2. Taylor expanded in m around inf

            \[\leadsto e^{\frac{-1}{4} \cdot {m}^{2}} \]
          3. Step-by-step derivation
            1. Applied rewrites97.0%

              \[\leadsto e^{\left(m \cdot m\right) \cdot -0.25} \]

            if -54 < m

            1. Initial program 79.7%

              \[\cos \left(\frac{K \cdot \left(m + n\right)}{2} - M\right) \cdot e^{\left(-{\left(\frac{m + n}{2} - M\right)}^{2}\right) - \left(\ell - \left|m - n\right|\right)} \]
            2. Add Preprocessing
            3. Taylor expanded in K around 0

              \[\leadsto \color{blue}{\cos \left(\mathsf{neg}\left(M\right)\right) \cdot e^{\left|m - n\right| - \left(\ell + {\left(\frac{1}{2} \cdot \left(m + n\right) - M\right)}^{2}\right)}} \]
            4. Step-by-step derivation
              1. *-commutativeN/A

                \[\leadsto \color{blue}{e^{\left|m - n\right| - \left(\ell + {\left(\frac{1}{2} \cdot \left(m + n\right) - M\right)}^{2}\right)} \cdot \cos \left(\mathsf{neg}\left(M\right)\right)} \]
              2. lower-*.f64N/A

                \[\leadsto \color{blue}{e^{\left|m - n\right| - \left(\ell + {\left(\frac{1}{2} \cdot \left(m + n\right) - M\right)}^{2}\right)} \cdot \cos \left(\mathsf{neg}\left(M\right)\right)} \]
            5. Applied rewrites97.9%

              \[\leadsto \color{blue}{e^{\left|m - n\right| - \left({\left(\mathsf{fma}\left(0.5, n + m, -M\right)\right)}^{2} + \ell\right)} \cdot \cos M} \]
            6. Taylor expanded in M around 0

              \[\leadsto e^{\left|m - n\right| - \left(\ell + \frac{1}{4} \cdot {\left(m + n\right)}^{2}\right)} \]
            7. Step-by-step derivation
              1. Applied rewrites85.7%

                \[\leadsto e^{\left|m - n\right| - \mathsf{fma}\left(0.25, {\left(n + m\right)}^{2}, \ell\right)} \]
              2. Taylor expanded in m around 0

                \[\leadsto e^{\left|m - n\right| - \mathsf{fma}\left(\frac{1}{4}, {n}^{2}, \ell\right)} \]
              3. Step-by-step derivation
                1. Applied rewrites70.7%

                  \[\leadsto e^{\left|m - n\right| - \mathsf{fma}\left(0.25, n \cdot n, \ell\right)} \]
              4. Recombined 2 regimes into one program.
              5. Final simplification77.5%

                \[\leadsto \begin{array}{l} \mathbf{if}\;m \leq -54:\\ \;\;\;\;e^{-0.25 \cdot \left(m \cdot m\right)}\\ \mathbf{else}:\\ \;\;\;\;e^{\left|n - m\right| - \mathsf{fma}\left(0.25, n \cdot n, \ell\right)}\\ \end{array} \]
              6. Add Preprocessing

              Alternative 4: 68.5% accurate, 2.9× speedup?

              \[\begin{array}{l} \\ \begin{array}{l} t_0 := e^{\left(-0.25 \cdot n\right) \cdot n}\\ \mathbf{if}\;n \leq -31:\\ \;\;\;\;t\_0\\ \mathbf{elif}\;n \leq 54:\\ \;\;\;\;e^{-\ell}\\ \mathbf{else}:\\ \;\;\;\;t\_0\\ \end{array} \end{array} \]
              (FPCore (K m n M l)
               :precision binary64
               (let* ((t_0 (exp (* (* -0.25 n) n))))
                 (if (<= n -31.0) t_0 (if (<= n 54.0) (exp (- l)) t_0))))
              double code(double K, double m, double n, double M, double l) {
              	double t_0 = exp(((-0.25 * n) * n));
              	double tmp;
              	if (n <= -31.0) {
              		tmp = t_0;
              	} else if (n <= 54.0) {
              		tmp = exp(-l);
              	} else {
              		tmp = t_0;
              	}
              	return tmp;
              }
              
              real(8) function code(k, m, n, m_1, l)
                  real(8), intent (in) :: k
                  real(8), intent (in) :: m
                  real(8), intent (in) :: n
                  real(8), intent (in) :: m_1
                  real(8), intent (in) :: l
                  real(8) :: t_0
                  real(8) :: tmp
                  t_0 = exp((((-0.25d0) * n) * n))
                  if (n <= (-31.0d0)) then
                      tmp = t_0
                  else if (n <= 54.0d0) then
                      tmp = exp(-l)
                  else
                      tmp = t_0
                  end if
                  code = tmp
              end function
              
              public static double code(double K, double m, double n, double M, double l) {
              	double t_0 = Math.exp(((-0.25 * n) * n));
              	double tmp;
              	if (n <= -31.0) {
              		tmp = t_0;
              	} else if (n <= 54.0) {
              		tmp = Math.exp(-l);
              	} else {
              		tmp = t_0;
              	}
              	return tmp;
              }
              
              def code(K, m, n, M, l):
              	t_0 = math.exp(((-0.25 * n) * n))
              	tmp = 0
              	if n <= -31.0:
              		tmp = t_0
              	elif n <= 54.0:
              		tmp = math.exp(-l)
              	else:
              		tmp = t_0
              	return tmp
              
              function code(K, m, n, M, l)
              	t_0 = exp(Float64(Float64(-0.25 * n) * n))
              	tmp = 0.0
              	if (n <= -31.0)
              		tmp = t_0;
              	elseif (n <= 54.0)
              		tmp = exp(Float64(-l));
              	else
              		tmp = t_0;
              	end
              	return tmp
              end
              
              function tmp_2 = code(K, m, n, M, l)
              	t_0 = exp(((-0.25 * n) * n));
              	tmp = 0.0;
              	if (n <= -31.0)
              		tmp = t_0;
              	elseif (n <= 54.0)
              		tmp = exp(-l);
              	else
              		tmp = t_0;
              	end
              	tmp_2 = tmp;
              end
              
              code[K_, m_, n_, M_, l_] := Block[{t$95$0 = N[Exp[N[(N[(-0.25 * n), $MachinePrecision] * n), $MachinePrecision]], $MachinePrecision]}, If[LessEqual[n, -31.0], t$95$0, If[LessEqual[n, 54.0], N[Exp[(-l)], $MachinePrecision], t$95$0]]]
              
              \begin{array}{l}
              
              \\
              \begin{array}{l}
              t_0 := e^{\left(-0.25 \cdot n\right) \cdot n}\\
              \mathbf{if}\;n \leq -31:\\
              \;\;\;\;t\_0\\
              
              \mathbf{elif}\;n \leq 54:\\
              \;\;\;\;e^{-\ell}\\
              
              \mathbf{else}:\\
              \;\;\;\;t\_0\\
              
              
              \end{array}
              \end{array}
              
              Derivation
              1. Split input into 2 regimes
              2. if n < -31 or 54 < n

                1. Initial program 73.3%

                  \[\cos \left(\frac{K \cdot \left(m + n\right)}{2} - M\right) \cdot e^{\left(-{\left(\frac{m + n}{2} - M\right)}^{2}\right) - \left(\ell - \left|m - n\right|\right)} \]
                2. Add Preprocessing
                3. Taylor expanded in K around 0

                  \[\leadsto \color{blue}{\cos \left(\mathsf{neg}\left(M\right)\right) \cdot e^{\left|m - n\right| - \left(\ell + {\left(\frac{1}{2} \cdot \left(m + n\right) - M\right)}^{2}\right)}} \]
                4. Step-by-step derivation
                  1. *-commutativeN/A

                    \[\leadsto \color{blue}{e^{\left|m - n\right| - \left(\ell + {\left(\frac{1}{2} \cdot \left(m + n\right) - M\right)}^{2}\right)} \cdot \cos \left(\mathsf{neg}\left(M\right)\right)} \]
                  2. lower-*.f64N/A

                    \[\leadsto \color{blue}{e^{\left|m - n\right| - \left(\ell + {\left(\frac{1}{2} \cdot \left(m + n\right) - M\right)}^{2}\right)} \cdot \cos \left(\mathsf{neg}\left(M\right)\right)} \]
                5. Applied rewrites100.0%

                  \[\leadsto \color{blue}{e^{\left|m - n\right| - \left({\left(\mathsf{fma}\left(0.5, n + m, -M\right)\right)}^{2} + \ell\right)} \cdot \cos M} \]
                6. Taylor expanded in M around 0

                  \[\leadsto e^{\left|m - n\right| - \left(\ell + \frac{1}{4} \cdot {\left(m + n\right)}^{2}\right)} \]
                7. Step-by-step derivation
                  1. Applied rewrites97.7%

                    \[\leadsto e^{\left|m - n\right| - \mathsf{fma}\left(0.25, {\left(n + m\right)}^{2}, \ell\right)} \]
                  2. Taylor expanded in n around inf

                    \[\leadsto e^{\frac{-1}{4} \cdot {n}^{2}} \]
                  3. Step-by-step derivation
                    1. Applied rewrites97.0%

                      \[\leadsto e^{\left(-0.25 \cdot n\right) \cdot n} \]

                    if -31 < n < 54

                    1. Initial program 84.4%

                      \[\cos \left(\frac{K \cdot \left(m + n\right)}{2} - M\right) \cdot e^{\left(-{\left(\frac{m + n}{2} - M\right)}^{2}\right) - \left(\ell - \left|m - n\right|\right)} \]
                    2. Add Preprocessing
                    3. Taylor expanded in K around 0

                      \[\leadsto \color{blue}{\cos \left(\mathsf{neg}\left(M\right)\right) \cdot e^{\left|m - n\right| - \left(\ell + {\left(\frac{1}{2} \cdot \left(m + n\right) - M\right)}^{2}\right)}} \]
                    4. Step-by-step derivation
                      1. *-commutativeN/A

                        \[\leadsto \color{blue}{e^{\left|m - n\right| - \left(\ell + {\left(\frac{1}{2} \cdot \left(m + n\right) - M\right)}^{2}\right)} \cdot \cos \left(\mathsf{neg}\left(M\right)\right)} \]
                      2. lower-*.f64N/A

                        \[\leadsto \color{blue}{e^{\left|m - n\right| - \left(\ell + {\left(\frac{1}{2} \cdot \left(m + n\right) - M\right)}^{2}\right)} \cdot \cos \left(\mathsf{neg}\left(M\right)\right)} \]
                    5. Applied rewrites96.8%

                      \[\leadsto \color{blue}{e^{\left|m - n\right| - \left({\left(\mathsf{fma}\left(0.5, n + m, -M\right)\right)}^{2} + \ell\right)} \cdot \cos M} \]
                    6. Taylor expanded in M around 0

                      \[\leadsto e^{\left|m - n\right| - \left(\ell + \frac{1}{4} \cdot {\left(m + n\right)}^{2}\right)} \]
                    7. Step-by-step derivation
                      1. Applied rewrites80.7%

                        \[\leadsto e^{\left|m - n\right| - \mathsf{fma}\left(0.25, {\left(n + m\right)}^{2}, \ell\right)} \]
                      2. Taylor expanded in l around inf

                        \[\leadsto e^{-1 \cdot \ell} \]
                      3. Step-by-step derivation
                        1. Applied rewrites45.9%

                          \[\leadsto e^{-\ell} \]
                      4. Recombined 2 regimes into one program.
                      5. Add Preprocessing

                      Alternative 5: 65.6% accurate, 3.1× speedup?

                      \[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;n \leq 55:\\ \;\;\;\;e^{-0.25 \cdot \left(m \cdot m\right)}\\ \mathbf{else}:\\ \;\;\;\;e^{\left(-0.25 \cdot n\right) \cdot n}\\ \end{array} \end{array} \]
                      (FPCore (K m n M l)
                       :precision binary64
                       (if (<= n 55.0) (exp (* -0.25 (* m m))) (exp (* (* -0.25 n) n))))
                      double code(double K, double m, double n, double M, double l) {
                      	double tmp;
                      	if (n <= 55.0) {
                      		tmp = exp((-0.25 * (m * m)));
                      	} else {
                      		tmp = exp(((-0.25 * n) * n));
                      	}
                      	return tmp;
                      }
                      
                      real(8) function code(k, m, n, m_1, l)
                          real(8), intent (in) :: k
                          real(8), intent (in) :: m
                          real(8), intent (in) :: n
                          real(8), intent (in) :: m_1
                          real(8), intent (in) :: l
                          real(8) :: tmp
                          if (n <= 55.0d0) then
                              tmp = exp(((-0.25d0) * (m * m)))
                          else
                              tmp = exp((((-0.25d0) * n) * n))
                          end if
                          code = tmp
                      end function
                      
                      public static double code(double K, double m, double n, double M, double l) {
                      	double tmp;
                      	if (n <= 55.0) {
                      		tmp = Math.exp((-0.25 * (m * m)));
                      	} else {
                      		tmp = Math.exp(((-0.25 * n) * n));
                      	}
                      	return tmp;
                      }
                      
                      def code(K, m, n, M, l):
                      	tmp = 0
                      	if n <= 55.0:
                      		tmp = math.exp((-0.25 * (m * m)))
                      	else:
                      		tmp = math.exp(((-0.25 * n) * n))
                      	return tmp
                      
                      function code(K, m, n, M, l)
                      	tmp = 0.0
                      	if (n <= 55.0)
                      		tmp = exp(Float64(-0.25 * Float64(m * m)));
                      	else
                      		tmp = exp(Float64(Float64(-0.25 * n) * n));
                      	end
                      	return tmp
                      end
                      
                      function tmp_2 = code(K, m, n, M, l)
                      	tmp = 0.0;
                      	if (n <= 55.0)
                      		tmp = exp((-0.25 * (m * m)));
                      	else
                      		tmp = exp(((-0.25 * n) * n));
                      	end
                      	tmp_2 = tmp;
                      end
                      
                      code[K_, m_, n_, M_, l_] := If[LessEqual[n, 55.0], N[Exp[N[(-0.25 * N[(m * m), $MachinePrecision]), $MachinePrecision]], $MachinePrecision], N[Exp[N[(N[(-0.25 * n), $MachinePrecision] * n), $MachinePrecision]], $MachinePrecision]]
                      
                      \begin{array}{l}
                      
                      \\
                      \begin{array}{l}
                      \mathbf{if}\;n \leq 55:\\
                      \;\;\;\;e^{-0.25 \cdot \left(m \cdot m\right)}\\
                      
                      \mathbf{else}:\\
                      \;\;\;\;e^{\left(-0.25 \cdot n\right) \cdot n}\\
                      
                      
                      \end{array}
                      \end{array}
                      
                      Derivation
                      1. Split input into 2 regimes
                      2. if n < 55

                        1. Initial program 80.1%

                          \[\cos \left(\frac{K \cdot \left(m + n\right)}{2} - M\right) \cdot e^{\left(-{\left(\frac{m + n}{2} - M\right)}^{2}\right) - \left(\ell - \left|m - n\right|\right)} \]
                        2. Add Preprocessing
                        3. Taylor expanded in K around 0

                          \[\leadsto \color{blue}{\cos \left(\mathsf{neg}\left(M\right)\right) \cdot e^{\left|m - n\right| - \left(\ell + {\left(\frac{1}{2} \cdot \left(m + n\right) - M\right)}^{2}\right)}} \]
                        4. Step-by-step derivation
                          1. *-commutativeN/A

                            \[\leadsto \color{blue}{e^{\left|m - n\right| - \left(\ell + {\left(\frac{1}{2} \cdot \left(m + n\right) - M\right)}^{2}\right)} \cdot \cos \left(\mathsf{neg}\left(M\right)\right)} \]
                          2. lower-*.f64N/A

                            \[\leadsto \color{blue}{e^{\left|m - n\right| - \left(\ell + {\left(\frac{1}{2} \cdot \left(m + n\right) - M\right)}^{2}\right)} \cdot \cos \left(\mathsf{neg}\left(M\right)\right)} \]
                        5. Applied rewrites97.9%

                          \[\leadsto \color{blue}{e^{\left|m - n\right| - \left({\left(\mathsf{fma}\left(0.5, n + m, -M\right)\right)}^{2} + \ell\right)} \cdot \cos M} \]
                        6. Taylor expanded in M around 0

                          \[\leadsto e^{\left|m - n\right| - \left(\ell + \frac{1}{4} \cdot {\left(m + n\right)}^{2}\right)} \]
                        7. Step-by-step derivation
                          1. Applied rewrites87.2%

                            \[\leadsto e^{\left|m - n\right| - \mathsf{fma}\left(0.25, {\left(n + m\right)}^{2}, \ell\right)} \]
                          2. Taylor expanded in m around inf

                            \[\leadsto e^{\frac{-1}{4} \cdot {m}^{2}} \]
                          3. Step-by-step derivation
                            1. Applied rewrites55.6%

                              \[\leadsto e^{\left(m \cdot m\right) \cdot -0.25} \]

                            if 55 < n

                            1. Initial program 74.6%

                              \[\cos \left(\frac{K \cdot \left(m + n\right)}{2} - M\right) \cdot e^{\left(-{\left(\frac{m + n}{2} - M\right)}^{2}\right) - \left(\ell - \left|m - n\right|\right)} \]
                            2. Add Preprocessing
                            3. Taylor expanded in K around 0

                              \[\leadsto \color{blue}{\cos \left(\mathsf{neg}\left(M\right)\right) \cdot e^{\left|m - n\right| - \left(\ell + {\left(\frac{1}{2} \cdot \left(m + n\right) - M\right)}^{2}\right)}} \]
                            4. Step-by-step derivation
                              1. *-commutativeN/A

                                \[\leadsto \color{blue}{e^{\left|m - n\right| - \left(\ell + {\left(\frac{1}{2} \cdot \left(m + n\right) - M\right)}^{2}\right)} \cdot \cos \left(\mathsf{neg}\left(M\right)\right)} \]
                              2. lower-*.f64N/A

                                \[\leadsto \color{blue}{e^{\left|m - n\right| - \left(\ell + {\left(\frac{1}{2} \cdot \left(m + n\right) - M\right)}^{2}\right)} \cdot \cos \left(\mathsf{neg}\left(M\right)\right)} \]
                            5. Applied rewrites100.0%

                              \[\leadsto \color{blue}{e^{\left|m - n\right| - \left({\left(\mathsf{fma}\left(0.5, n + m, -M\right)\right)}^{2} + \ell\right)} \cdot \cos M} \]
                            6. Taylor expanded in M around 0

                              \[\leadsto e^{\left|m - n\right| - \left(\ell + \frac{1}{4} \cdot {\left(m + n\right)}^{2}\right)} \]
                            7. Step-by-step derivation
                              1. Applied rewrites95.6%

                                \[\leadsto e^{\left|m - n\right| - \mathsf{fma}\left(0.25, {\left(n + m\right)}^{2}, \ell\right)} \]
                              2. Taylor expanded in n around inf

                                \[\leadsto e^{\frac{-1}{4} \cdot {n}^{2}} \]
                              3. Step-by-step derivation
                                1. Applied rewrites95.6%

                                  \[\leadsto e^{\left(-0.25 \cdot n\right) \cdot n} \]
                              4. Recombined 2 regimes into one program.
                              5. Final simplification66.1%

                                \[\leadsto \begin{array}{l} \mathbf{if}\;n \leq 55:\\ \;\;\;\;e^{-0.25 \cdot \left(m \cdot m\right)}\\ \mathbf{else}:\\ \;\;\;\;e^{\left(-0.25 \cdot n\right) \cdot n}\\ \end{array} \]
                              6. Add Preprocessing

                              Alternative 6: 36.1% accurate, 3.5× speedup?

                              \[\begin{array}{l} \\ e^{-\ell} \end{array} \]
                              (FPCore (K m n M l) :precision binary64 (exp (- l)))
                              double code(double K, double m, double n, double M, double l) {
                              	return exp(-l);
                              }
                              
                              real(8) function code(k, m, n, m_1, l)
                                  real(8), intent (in) :: k
                                  real(8), intent (in) :: m
                                  real(8), intent (in) :: n
                                  real(8), intent (in) :: m_1
                                  real(8), intent (in) :: l
                                  code = exp(-l)
                              end function
                              
                              public static double code(double K, double m, double n, double M, double l) {
                              	return Math.exp(-l);
                              }
                              
                              def code(K, m, n, M, l):
                              	return math.exp(-l)
                              
                              function code(K, m, n, M, l)
                              	return exp(Float64(-l))
                              end
                              
                              function tmp = code(K, m, n, M, l)
                              	tmp = exp(-l);
                              end
                              
                              code[K_, m_, n_, M_, l_] := N[Exp[(-l)], $MachinePrecision]
                              
                              \begin{array}{l}
                              
                              \\
                              e^{-\ell}
                              \end{array}
                              
                              Derivation
                              1. Initial program 78.7%

                                \[\cos \left(\frac{K \cdot \left(m + n\right)}{2} - M\right) \cdot e^{\left(-{\left(\frac{m + n}{2} - M\right)}^{2}\right) - \left(\ell - \left|m - n\right|\right)} \]
                              2. Add Preprocessing
                              3. Taylor expanded in K around 0

                                \[\leadsto \color{blue}{\cos \left(\mathsf{neg}\left(M\right)\right) \cdot e^{\left|m - n\right| - \left(\ell + {\left(\frac{1}{2} \cdot \left(m + n\right) - M\right)}^{2}\right)}} \]
                              4. Step-by-step derivation
                                1. *-commutativeN/A

                                  \[\leadsto \color{blue}{e^{\left|m - n\right| - \left(\ell + {\left(\frac{1}{2} \cdot \left(m + n\right) - M\right)}^{2}\right)} \cdot \cos \left(\mathsf{neg}\left(M\right)\right)} \]
                                2. lower-*.f64N/A

                                  \[\leadsto \color{blue}{e^{\left|m - n\right| - \left(\ell + {\left(\frac{1}{2} \cdot \left(m + n\right) - M\right)}^{2}\right)} \cdot \cos \left(\mathsf{neg}\left(M\right)\right)} \]
                              5. Applied rewrites98.5%

                                \[\leadsto \color{blue}{e^{\left|m - n\right| - \left({\left(\mathsf{fma}\left(0.5, n + m, -M\right)\right)}^{2} + \ell\right)} \cdot \cos M} \]
                              6. Taylor expanded in M around 0

                                \[\leadsto e^{\left|m - n\right| - \left(\ell + \frac{1}{4} \cdot {\left(m + n\right)}^{2}\right)} \]
                              7. Step-by-step derivation
                                1. Applied rewrites89.4%

                                  \[\leadsto e^{\left|m - n\right| - \mathsf{fma}\left(0.25, {\left(n + m\right)}^{2}, \ell\right)} \]
                                2. Taylor expanded in l around inf

                                  \[\leadsto e^{-1 \cdot \ell} \]
                                3. Step-by-step derivation
                                  1. Applied rewrites36.0%

                                    \[\leadsto e^{-\ell} \]
                                  2. Add Preprocessing

                                  Reproduce

                                  ?
                                  herbie shell --seed 2024332 
                                  (FPCore (K m n M l)
                                    :name "Maksimov and Kolovsky, Equation (32)"
                                    :precision binary64
                                    (* (cos (- (/ (* K (+ m n)) 2.0) M)) (exp (- (- (pow (- (/ (+ m n) 2.0) M) 2.0)) (- l (fabs (- m n)))))))