Numeric.SpecFunctions:logGammaL from math-functions-0.1.5.2

Percentage Accurate: 99.6% → 99.6%
Time: 26.0s
Alternatives: 17
Speedup: N/A×

Specification

?
\[\begin{array}{l} \\ \left(\left(\log \left(x + y\right) + \log z\right) - t\right) + \left(a - 0.5\right) \cdot \log t \end{array} \]
(FPCore (x y z t a)
 :precision binary64
 (+ (- (+ (log (+ x y)) (log z)) t) (* (- a 0.5) (log t))))
double code(double x, double y, double z, double t, double a) {
	return ((log((x + y)) + log(z)) - t) + ((a - 0.5) * log(t));
}
real(8) function code(x, y, z, t, a)
    real(8), intent (in) :: x
    real(8), intent (in) :: y
    real(8), intent (in) :: z
    real(8), intent (in) :: t
    real(8), intent (in) :: a
    code = ((log((x + y)) + log(z)) - t) + ((a - 0.5d0) * log(t))
end function
public static double code(double x, double y, double z, double t, double a) {
	return ((Math.log((x + y)) + Math.log(z)) - t) + ((a - 0.5) * Math.log(t));
}
def code(x, y, z, t, a):
	return ((math.log((x + y)) + math.log(z)) - t) + ((a - 0.5) * math.log(t))
function code(x, y, z, t, a)
	return Float64(Float64(Float64(log(Float64(x + y)) + log(z)) - t) + Float64(Float64(a - 0.5) * log(t)))
end
function tmp = code(x, y, z, t, a)
	tmp = ((log((x + y)) + log(z)) - t) + ((a - 0.5) * log(t));
end
code[x_, y_, z_, t_, a_] := N[(N[(N[(N[Log[N[(x + y), $MachinePrecision]], $MachinePrecision] + N[Log[z], $MachinePrecision]), $MachinePrecision] - t), $MachinePrecision] + N[(N[(a - 0.5), $MachinePrecision] * N[Log[t], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}

\\
\left(\left(\log \left(x + y\right) + \log z\right) - t\right) + \left(a - 0.5\right) \cdot \log t
\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 17 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: 99.6% accurate, 1.0× speedup?

\[\begin{array}{l} \\ \left(\left(\log \left(x + y\right) + \log z\right) - t\right) + \left(a - 0.5\right) \cdot \log t \end{array} \]
(FPCore (x y z t a)
 :precision binary64
 (+ (- (+ (log (+ x y)) (log z)) t) (* (- a 0.5) (log t))))
double code(double x, double y, double z, double t, double a) {
	return ((log((x + y)) + log(z)) - t) + ((a - 0.5) * log(t));
}
real(8) function code(x, y, z, t, a)
    real(8), intent (in) :: x
    real(8), intent (in) :: y
    real(8), intent (in) :: z
    real(8), intent (in) :: t
    real(8), intent (in) :: a
    code = ((log((x + y)) + log(z)) - t) + ((a - 0.5d0) * log(t))
end function
public static double code(double x, double y, double z, double t, double a) {
	return ((Math.log((x + y)) + Math.log(z)) - t) + ((a - 0.5) * Math.log(t));
}
def code(x, y, z, t, a):
	return ((math.log((x + y)) + math.log(z)) - t) + ((a - 0.5) * math.log(t))
function code(x, y, z, t, a)
	return Float64(Float64(Float64(log(Float64(x + y)) + log(z)) - t) + Float64(Float64(a - 0.5) * log(t)))
end
function tmp = code(x, y, z, t, a)
	tmp = ((log((x + y)) + log(z)) - t) + ((a - 0.5) * log(t));
end
code[x_, y_, z_, t_, a_] := N[(N[(N[(N[Log[N[(x + y), $MachinePrecision]], $MachinePrecision] + N[Log[z], $MachinePrecision]), $MachinePrecision] - t), $MachinePrecision] + N[(N[(a - 0.5), $MachinePrecision] * N[Log[t], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}

\\
\left(\left(\log \left(x + y\right) + \log z\right) - t\right) + \left(a - 0.5\right) \cdot \log t
\end{array}

Alternative 1: 99.6% accurate, 0.8× speedup?

\[\begin{array}{l} \\ \log \left(x + y\right) + \mathsf{fma}\left(a + -0.5, \log t, \log z - t\right) \end{array} \]
(FPCore (x y z t a)
 :precision binary64
 (+ (log (+ x y)) (fma (+ a -0.5) (log t) (- (log z) t))))
double code(double x, double y, double z, double t, double a) {
	return log((x + y)) + fma((a + -0.5), log(t), (log(z) - t));
}
function code(x, y, z, t, a)
	return Float64(log(Float64(x + y)) + fma(Float64(a + -0.5), log(t), Float64(log(z) - t)))
end
code[x_, y_, z_, t_, a_] := N[(N[Log[N[(x + y), $MachinePrecision]], $MachinePrecision] + N[(N[(a + -0.5), $MachinePrecision] * N[Log[t], $MachinePrecision] + N[(N[Log[z], $MachinePrecision] - t), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}

\\
\log \left(x + y\right) + \mathsf{fma}\left(a + -0.5, \log t, \log z - t\right)
\end{array}
Derivation
  1. Initial program 99.6%

    \[\left(\left(\log \left(x + y\right) + \log z\right) - t\right) + \left(a - 0.5\right) \cdot \log t \]
  2. Step-by-step derivation
    1. associate--l+99.6%

      \[\leadsto \color{blue}{\left(\log \left(x + y\right) + \left(\log z - t\right)\right)} + \left(a - 0.5\right) \cdot \log t \]
    2. associate-+l+99.6%

      \[\leadsto \color{blue}{\log \left(x + y\right) + \left(\left(\log z - t\right) + \left(a - 0.5\right) \cdot \log t\right)} \]
    3. +-commutative99.6%

      \[\leadsto \log \left(x + y\right) + \color{blue}{\left(\left(a - 0.5\right) \cdot \log t + \left(\log z - t\right)\right)} \]
    4. fma-def99.6%

      \[\leadsto \log \left(x + y\right) + \color{blue}{\mathsf{fma}\left(a - 0.5, \log t, \log z - t\right)} \]
    5. remove-double-neg99.6%

      \[\leadsto \log \left(x + y\right) + \mathsf{fma}\left(\color{blue}{-\left(-\left(a - 0.5\right)\right)}, \log t, \log z - t\right) \]
    6. remove-double-neg99.6%

      \[\leadsto \log \left(x + y\right) + \mathsf{fma}\left(\color{blue}{a - 0.5}, \log t, \log z - t\right) \]
    7. sub-neg99.6%

      \[\leadsto \log \left(x + y\right) + \mathsf{fma}\left(\color{blue}{a + \left(-0.5\right)}, \log t, \log z - t\right) \]
    8. metadata-eval99.6%

      \[\leadsto \log \left(x + y\right) + \mathsf{fma}\left(a + \color{blue}{-0.5}, \log t, \log z - t\right) \]
  3. Simplified99.6%

    \[\leadsto \color{blue}{\log \left(x + y\right) + \mathsf{fma}\left(a + -0.5, \log t, \log z - t\right)} \]
  4. Final simplification99.6%

    \[\leadsto \log \left(x + y\right) + \mathsf{fma}\left(a + -0.5, \log t, \log z - t\right) \]

Alternative 2: 75.4% accurate, 1.0× speedup?

\[\begin{array}{l} \\ \begin{array}{l} t_1 := \mathsf{fma}\left(a + -0.5, \log t, -t\right)\\ \mathbf{if}\;a \leq -1.86 \cdot 10^{+34}:\\ \;\;\;\;t_1\\ \mathbf{elif}\;a \leq -1.7 \cdot 10^{-125}:\\ \;\;\;\;\left(\log t \cdot \left(a - 0.5\right) + \log \left(y \cdot z\right)\right) - t\\ \mathbf{elif}\;a \leq 1:\\ \;\;\;\;\left(\log y + \log \left(z \cdot {t}^{-0.5}\right)\right) - t\\ \mathbf{else}:\\ \;\;\;\;t_1\\ \end{array} \end{array} \]
(FPCore (x y z t a)
 :precision binary64
 (let* ((t_1 (fma (+ a -0.5) (log t) (- t))))
   (if (<= a -1.86e+34)
     t_1
     (if (<= a -1.7e-125)
       (- (+ (* (log t) (- a 0.5)) (log (* y z))) t)
       (if (<= a 1.0) (- (+ (log y) (log (* z (pow t -0.5)))) t) t_1)))))
double code(double x, double y, double z, double t, double a) {
	double t_1 = fma((a + -0.5), log(t), -t);
	double tmp;
	if (a <= -1.86e+34) {
		tmp = t_1;
	} else if (a <= -1.7e-125) {
		tmp = ((log(t) * (a - 0.5)) + log((y * z))) - t;
	} else if (a <= 1.0) {
		tmp = (log(y) + log((z * pow(t, -0.5)))) - t;
	} else {
		tmp = t_1;
	}
	return tmp;
}
function code(x, y, z, t, a)
	t_1 = fma(Float64(a + -0.5), log(t), Float64(-t))
	tmp = 0.0
	if (a <= -1.86e+34)
		tmp = t_1;
	elseif (a <= -1.7e-125)
		tmp = Float64(Float64(Float64(log(t) * Float64(a - 0.5)) + log(Float64(y * z))) - t);
	elseif (a <= 1.0)
		tmp = Float64(Float64(log(y) + log(Float64(z * (t ^ -0.5)))) - t);
	else
		tmp = t_1;
	end
	return tmp
end
code[x_, y_, z_, t_, a_] := Block[{t$95$1 = N[(N[(a + -0.5), $MachinePrecision] * N[Log[t], $MachinePrecision] + (-t)), $MachinePrecision]}, If[LessEqual[a, -1.86e+34], t$95$1, If[LessEqual[a, -1.7e-125], N[(N[(N[(N[Log[t], $MachinePrecision] * N[(a - 0.5), $MachinePrecision]), $MachinePrecision] + N[Log[N[(y * z), $MachinePrecision]], $MachinePrecision]), $MachinePrecision] - t), $MachinePrecision], If[LessEqual[a, 1.0], N[(N[(N[Log[y], $MachinePrecision] + N[Log[N[(z * N[Power[t, -0.5], $MachinePrecision]), $MachinePrecision]], $MachinePrecision]), $MachinePrecision] - t), $MachinePrecision], t$95$1]]]]
\begin{array}{l}

\\
\begin{array}{l}
t_1 := \mathsf{fma}\left(a + -0.5, \log t, -t\right)\\
\mathbf{if}\;a \leq -1.86 \cdot 10^{+34}:\\
\;\;\;\;t_1\\

\mathbf{elif}\;a \leq -1.7 \cdot 10^{-125}:\\
\;\;\;\;\left(\log t \cdot \left(a - 0.5\right) + \log \left(y \cdot z\right)\right) - t\\

\mathbf{elif}\;a \leq 1:\\
\;\;\;\;\left(\log y + \log \left(z \cdot {t}^{-0.5}\right)\right) - t\\

\mathbf{else}:\\
\;\;\;\;t_1\\


\end{array}
\end{array}
Derivation
  1. Split input into 3 regimes
  2. if a < -1.86e34 or 1 < a

    1. Initial program 99.5%

      \[\left(\left(\log \left(x + y\right) + \log z\right) - t\right) + \left(a - 0.5\right) \cdot \log t \]
    2. Step-by-step derivation
      1. associate--l+99.5%

        \[\leadsto \color{blue}{\left(\log \left(x + y\right) + \left(\log z - t\right)\right)} + \left(a - 0.5\right) \cdot \log t \]
      2. associate-+l+99.5%

        \[\leadsto \color{blue}{\log \left(x + y\right) + \left(\left(\log z - t\right) + \left(a - 0.5\right) \cdot \log t\right)} \]
      3. +-commutative99.5%

        \[\leadsto \log \left(x + y\right) + \color{blue}{\left(\left(a - 0.5\right) \cdot \log t + \left(\log z - t\right)\right)} \]
      4. fma-def99.5%

        \[\leadsto \log \left(x + y\right) + \color{blue}{\mathsf{fma}\left(a - 0.5, \log t, \log z - t\right)} \]
      5. remove-double-neg99.5%

        \[\leadsto \log \left(x + y\right) + \mathsf{fma}\left(\color{blue}{-\left(-\left(a - 0.5\right)\right)}, \log t, \log z - t\right) \]
      6. remove-double-neg99.5%

        \[\leadsto \log \left(x + y\right) + \mathsf{fma}\left(\color{blue}{a - 0.5}, \log t, \log z - t\right) \]
      7. sub-neg99.5%

        \[\leadsto \log \left(x + y\right) + \mathsf{fma}\left(\color{blue}{a + \left(-0.5\right)}, \log t, \log z - t\right) \]
      8. metadata-eval99.5%

        \[\leadsto \log \left(x + y\right) + \mathsf{fma}\left(a + \color{blue}{-0.5}, \log t, \log z - t\right) \]
    3. Simplified99.5%

      \[\leadsto \color{blue}{\log \left(x + y\right) + \mathsf{fma}\left(a + -0.5, \log t, \log z - t\right)} \]
    4. Step-by-step derivation
      1. +-commutative99.5%

        \[\leadsto \color{blue}{\mathsf{fma}\left(a + -0.5, \log t, \log z - t\right) + \log \left(x + y\right)} \]
      2. fma-udef99.5%

        \[\leadsto \color{blue}{\left(\left(a + -0.5\right) \cdot \log t + \left(\log z - t\right)\right)} + \log \left(x + y\right) \]
      3. associate-+r+99.5%

        \[\leadsto \color{blue}{\left(a + -0.5\right) \cdot \log t + \left(\left(\log z - t\right) + \log \left(x + y\right)\right)} \]
      4. +-commutative99.5%

        \[\leadsto \left(a + -0.5\right) \cdot \log t + \color{blue}{\left(\log \left(x + y\right) + \left(\log z - t\right)\right)} \]
      5. fma-def99.5%

        \[\leadsto \color{blue}{\mathsf{fma}\left(a + -0.5, \log t, \log \left(x + y\right) + \left(\log z - t\right)\right)} \]
      6. associate-+r-99.5%

        \[\leadsto \mathsf{fma}\left(a + -0.5, \log t, \color{blue}{\left(\log \left(x + y\right) + \log z\right) - t}\right) \]
      7. sum-log74.1%

        \[\leadsto \mathsf{fma}\left(a + -0.5, \log t, \color{blue}{\log \left(\left(x + y\right) \cdot z\right)} - t\right) \]
    5. Applied egg-rr74.1%

      \[\leadsto \color{blue}{\mathsf{fma}\left(a + -0.5, \log t, \log \left(\left(x + y\right) \cdot z\right) - t\right)} \]
    6. Taylor expanded in t around inf 98.9%

      \[\leadsto \mathsf{fma}\left(a + -0.5, \log t, \color{blue}{-1 \cdot t}\right) \]
    7. Step-by-step derivation
      1. neg-mul-198.9%

        \[\leadsto \mathsf{fma}\left(a + -0.5, \log t, \color{blue}{-t}\right) \]
    8. Simplified98.9%

      \[\leadsto \mathsf{fma}\left(a + -0.5, \log t, \color{blue}{-t}\right) \]

    if -1.86e34 < a < -1.69999999999999988e-125

    1. Initial program 99.4%

      \[\left(\left(\log \left(x + y\right) + \log z\right) - t\right) + \left(a - 0.5\right) \cdot \log t \]
    2. Step-by-step derivation
      1. associate--l+99.5%

        \[\leadsto \color{blue}{\left(\log \left(x + y\right) + \left(\log z - t\right)\right)} + \left(a - 0.5\right) \cdot \log t \]
      2. associate-+l+99.7%

        \[\leadsto \color{blue}{\log \left(x + y\right) + \left(\left(\log z - t\right) + \left(a - 0.5\right) \cdot \log t\right)} \]
      3. +-commutative99.7%

        \[\leadsto \log \left(x + y\right) + \color{blue}{\left(\left(a - 0.5\right) \cdot \log t + \left(\log z - t\right)\right)} \]
      4. fma-def99.7%

        \[\leadsto \log \left(x + y\right) + \color{blue}{\mathsf{fma}\left(a - 0.5, \log t, \log z - t\right)} \]
      5. remove-double-neg99.7%

        \[\leadsto \log \left(x + y\right) + \mathsf{fma}\left(\color{blue}{-\left(-\left(a - 0.5\right)\right)}, \log t, \log z - t\right) \]
      6. remove-double-neg99.7%

        \[\leadsto \log \left(x + y\right) + \mathsf{fma}\left(\color{blue}{a - 0.5}, \log t, \log z - t\right) \]
      7. sub-neg99.7%

        \[\leadsto \log \left(x + y\right) + \mathsf{fma}\left(\color{blue}{a + \left(-0.5\right)}, \log t, \log z - t\right) \]
      8. metadata-eval99.7%

        \[\leadsto \log \left(x + y\right) + \mathsf{fma}\left(a + \color{blue}{-0.5}, \log t, \log z - t\right) \]
    3. Simplified99.7%

      \[\leadsto \color{blue}{\log \left(x + y\right) + \mathsf{fma}\left(a + -0.5, \log t, \log z - t\right)} \]
    4. Step-by-step derivation
      1. add-sqr-sqrt46.2%

        \[\leadsto \color{blue}{\sqrt{\log \left(x + y\right) + \mathsf{fma}\left(a + -0.5, \log t, \log z - t\right)} \cdot \sqrt{\log \left(x + y\right) + \mathsf{fma}\left(a + -0.5, \log t, \log z - t\right)}} \]
      2. pow246.2%

        \[\leadsto \color{blue}{{\left(\sqrt{\log \left(x + y\right) + \mathsf{fma}\left(a + -0.5, \log t, \log z - t\right)}\right)}^{2}} \]
      3. +-commutative46.2%

        \[\leadsto {\left(\sqrt{\color{blue}{\mathsf{fma}\left(a + -0.5, \log t, \log z - t\right) + \log \left(x + y\right)}}\right)}^{2} \]
      4. fma-udef46.2%

        \[\leadsto {\left(\sqrt{\color{blue}{\left(\left(a + -0.5\right) \cdot \log t + \left(\log z - t\right)\right)} + \log \left(x + y\right)}\right)}^{2} \]
      5. associate-+r+46.2%

        \[\leadsto {\left(\sqrt{\color{blue}{\left(a + -0.5\right) \cdot \log t + \left(\left(\log z - t\right) + \log \left(x + y\right)\right)}}\right)}^{2} \]
      6. +-commutative46.2%

        \[\leadsto {\left(\sqrt{\left(a + -0.5\right) \cdot \log t + \color{blue}{\left(\log \left(x + y\right) + \left(\log z - t\right)\right)}}\right)}^{2} \]
      7. fma-def46.2%

        \[\leadsto {\left(\sqrt{\color{blue}{\mathsf{fma}\left(a + -0.5, \log t, \log \left(x + y\right) + \left(\log z - t\right)\right)}}\right)}^{2} \]
      8. associate-+r-46.0%

        \[\leadsto {\left(\sqrt{\mathsf{fma}\left(a + -0.5, \log t, \color{blue}{\left(\log \left(x + y\right) + \log z\right) - t}\right)}\right)}^{2} \]
      9. sum-log46.2%

        \[\leadsto {\left(\sqrt{\mathsf{fma}\left(a + -0.5, \log t, \color{blue}{\log \left(\left(x + y\right) \cdot z\right)} - t\right)}\right)}^{2} \]
    5. Applied egg-rr46.2%

      \[\leadsto \color{blue}{{\left(\sqrt{\mathsf{fma}\left(a + -0.5, \log t, \log \left(\left(x + y\right) \cdot z\right) - t\right)}\right)}^{2}} \]
    6. Taylor expanded in x around 0 53.7%

      \[\leadsto \color{blue}{\left(\log \left(y \cdot z\right) + \left(a - 0.5\right) \cdot \log t\right) - t} \]

    if -1.69999999999999988e-125 < a < 1

    1. Initial program 99.6%

      \[\left(\left(\log \left(x + y\right) + \log z\right) - t\right) + \left(a - 0.5\right) \cdot \log t \]
    2. Step-by-step derivation
      1. associate--l+99.6%

        \[\leadsto \color{blue}{\left(\log \left(x + y\right) + \left(\log z - t\right)\right)} + \left(a - 0.5\right) \cdot \log t \]
      2. +-commutative99.6%

        \[\leadsto \color{blue}{\left(\left(\log z - t\right) + \log \left(x + y\right)\right)} + \left(a - 0.5\right) \cdot \log t \]
      3. associate-+l+99.5%

        \[\leadsto \color{blue}{\left(\log z - t\right) + \left(\log \left(x + y\right) + \left(a - 0.5\right) \cdot \log t\right)} \]
      4. +-commutative99.5%

        \[\leadsto \left(\log z - t\right) + \color{blue}{\left(\left(a - 0.5\right) \cdot \log t + \log \left(x + y\right)\right)} \]
      5. fma-def99.5%

        \[\leadsto \left(\log z - t\right) + \color{blue}{\mathsf{fma}\left(a - 0.5, \log t, \log \left(x + y\right)\right)} \]
      6. sub-neg99.5%

        \[\leadsto \left(\log z - t\right) + \mathsf{fma}\left(\color{blue}{a + \left(-0.5\right)}, \log t, \log \left(x + y\right)\right) \]
      7. metadata-eval99.5%

        \[\leadsto \left(\log z - t\right) + \mathsf{fma}\left(a + \color{blue}{-0.5}, \log t, \log \left(x + y\right)\right) \]
    3. Simplified99.5%

      \[\leadsto \color{blue}{\left(\log z - t\right) + \mathsf{fma}\left(a + -0.5, \log t, \log \left(x + y\right)\right)} \]
    4. Taylor expanded in x around 0 69.5%

      \[\leadsto \left(\log z - t\right) + \color{blue}{\left(\left(a - 0.5\right) \cdot \log t + \log y\right)} \]
    5. Taylor expanded in a around 0 69.5%

      \[\leadsto \color{blue}{\left(\log z + \left(\log y + -0.5 \cdot \log t\right)\right) - t} \]
    6. Step-by-step derivation
      1. associate-+r+69.5%

        \[\leadsto \color{blue}{\left(\left(\log z + \log y\right) + -0.5 \cdot \log t\right)} - t \]
      2. log-prod56.5%

        \[\leadsto \left(\color{blue}{\log \left(z \cdot y\right)} + -0.5 \cdot \log t\right) - t \]
      3. *-commutative56.5%

        \[\leadsto \left(\log \left(z \cdot y\right) + \color{blue}{\log t \cdot -0.5}\right) - t \]
    7. Simplified56.5%

      \[\leadsto \color{blue}{\left(\log \left(z \cdot y\right) + \log t \cdot -0.5\right) - t} \]
    8. Taylor expanded in z around 0 69.5%

      \[\leadsto \color{blue}{\left(\log z + \left(\log y + -0.5 \cdot \log t\right)\right)} - t \]
    9. Step-by-step derivation
      1. associate-+r+69.5%

        \[\leadsto \color{blue}{\left(\left(\log z + \log y\right) + -0.5 \cdot \log t\right)} - t \]
      2. +-commutative69.5%

        \[\leadsto \left(\color{blue}{\left(\log y + \log z\right)} + -0.5 \cdot \log t\right) - t \]
      3. log-prod56.5%

        \[\leadsto \left(\color{blue}{\log \left(y \cdot z\right)} + -0.5 \cdot \log t\right) - t \]
      4. log-pow56.5%

        \[\leadsto \left(\log \left(y \cdot z\right) + \color{blue}{\log \left({t}^{-0.5}\right)}\right) - t \]
      5. log-prod51.3%

        \[\leadsto \color{blue}{\log \left(\left(y \cdot z\right) \cdot {t}^{-0.5}\right)} - t \]
      6. associate-*l*53.9%

        \[\leadsto \log \color{blue}{\left(y \cdot \left(z \cdot {t}^{-0.5}\right)\right)} - t \]
    10. Simplified53.9%

      \[\leadsto \color{blue}{\log \left(y \cdot \left(z \cdot {t}^{-0.5}\right)\right)} - t \]
    11. Step-by-step derivation
      1. *-commutative53.9%

        \[\leadsto \log \color{blue}{\left(\left(z \cdot {t}^{-0.5}\right) \cdot y\right)} - t \]
      2. log-prod66.9%

        \[\leadsto \color{blue}{\left(\log \left(z \cdot {t}^{-0.5}\right) + \log y\right)} - t \]
    12. Applied egg-rr66.9%

      \[\leadsto \color{blue}{\left(\log \left(z \cdot {t}^{-0.5}\right) + \log y\right)} - t \]
  3. Recombined 3 regimes into one program.
  4. Final simplification81.4%

    \[\leadsto \begin{array}{l} \mathbf{if}\;a \leq -1.86 \cdot 10^{+34}:\\ \;\;\;\;\mathsf{fma}\left(a + -0.5, \log t, -t\right)\\ \mathbf{elif}\;a \leq -1.7 \cdot 10^{-125}:\\ \;\;\;\;\left(\log t \cdot \left(a - 0.5\right) + \log \left(y \cdot z\right)\right) - t\\ \mathbf{elif}\;a \leq 1:\\ \;\;\;\;\left(\log y + \log \left(z \cdot {t}^{-0.5}\right)\right) - t\\ \mathbf{else}:\\ \;\;\;\;\mathsf{fma}\left(a + -0.5, \log t, -t\right)\\ \end{array} \]

Alternative 3: 99.6% accurate, 1.0× speedup?

\[\begin{array}{l} \\ \left(\log \left(x + y\right) + \left(\log z - t\right)\right) + \left(a + -0.5\right) \cdot \log t \end{array} \]
(FPCore (x y z t a)
 :precision binary64
 (+ (+ (log (+ x y)) (- (log z) t)) (* (+ a -0.5) (log t))))
double code(double x, double y, double z, double t, double a) {
	return (log((x + y)) + (log(z) - t)) + ((a + -0.5) * log(t));
}
real(8) function code(x, y, z, t, a)
    real(8), intent (in) :: x
    real(8), intent (in) :: y
    real(8), intent (in) :: z
    real(8), intent (in) :: t
    real(8), intent (in) :: a
    code = (log((x + y)) + (log(z) - t)) + ((a + (-0.5d0)) * log(t))
end function
public static double code(double x, double y, double z, double t, double a) {
	return (Math.log((x + y)) + (Math.log(z) - t)) + ((a + -0.5) * Math.log(t));
}
def code(x, y, z, t, a):
	return (math.log((x + y)) + (math.log(z) - t)) + ((a + -0.5) * math.log(t))
function code(x, y, z, t, a)
	return Float64(Float64(log(Float64(x + y)) + Float64(log(z) - t)) + Float64(Float64(a + -0.5) * log(t)))
end
function tmp = code(x, y, z, t, a)
	tmp = (log((x + y)) + (log(z) - t)) + ((a + -0.5) * log(t));
end
code[x_, y_, z_, t_, a_] := N[(N[(N[Log[N[(x + y), $MachinePrecision]], $MachinePrecision] + N[(N[Log[z], $MachinePrecision] - t), $MachinePrecision]), $MachinePrecision] + N[(N[(a + -0.5), $MachinePrecision] * N[Log[t], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}

\\
\left(\log \left(x + y\right) + \left(\log z - t\right)\right) + \left(a + -0.5\right) \cdot \log t
\end{array}
Derivation
  1. Initial program 99.6%

    \[\left(\left(\log \left(x + y\right) + \log z\right) - t\right) + \left(a - 0.5\right) \cdot \log t \]
  2. Step-by-step derivation
    1. associate--l+99.6%

      \[\leadsto \color{blue}{\left(\log \left(x + y\right) + \left(\log z - t\right)\right)} + \left(a - 0.5\right) \cdot \log t \]
    2. sub-neg99.6%

      \[\leadsto \left(\log \left(x + y\right) + \left(\log z - t\right)\right) + \color{blue}{\left(a + \left(-0.5\right)\right)} \cdot \log t \]
    3. metadata-eval99.6%

      \[\leadsto \left(\log \left(x + y\right) + \left(\log z - t\right)\right) + \left(a + \color{blue}{-0.5}\right) \cdot \log t \]
  3. Simplified99.6%

    \[\leadsto \color{blue}{\left(\log \left(x + y\right) + \left(\log z - t\right)\right) + \left(a + -0.5\right) \cdot \log t} \]
  4. Final simplification99.6%

    \[\leadsto \left(\log \left(x + y\right) + \left(\log z - t\right)\right) + \left(a + -0.5\right) \cdot \log t \]

Alternative 4: 80.3% accurate, 1.0× speedup?

\[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;t \leq 480:\\ \;\;\;\;\log z + \left(\log t \cdot \left(a - 0.5\right) + \log y\right)\\ \mathbf{else}:\\ \;\;\;\;\mathsf{fma}\left(a + -0.5, \log t, -t\right)\\ \end{array} \end{array} \]
(FPCore (x y z t a)
 :precision binary64
 (if (<= t 480.0)
   (+ (log z) (+ (* (log t) (- a 0.5)) (log y)))
   (fma (+ a -0.5) (log t) (- t))))
double code(double x, double y, double z, double t, double a) {
	double tmp;
	if (t <= 480.0) {
		tmp = log(z) + ((log(t) * (a - 0.5)) + log(y));
	} else {
		tmp = fma((a + -0.5), log(t), -t);
	}
	return tmp;
}
function code(x, y, z, t, a)
	tmp = 0.0
	if (t <= 480.0)
		tmp = Float64(log(z) + Float64(Float64(log(t) * Float64(a - 0.5)) + log(y)));
	else
		tmp = fma(Float64(a + -0.5), log(t), Float64(-t));
	end
	return tmp
end
code[x_, y_, z_, t_, a_] := If[LessEqual[t, 480.0], N[(N[Log[z], $MachinePrecision] + N[(N[(N[Log[t], $MachinePrecision] * N[(a - 0.5), $MachinePrecision]), $MachinePrecision] + N[Log[y], $MachinePrecision]), $MachinePrecision]), $MachinePrecision], N[(N[(a + -0.5), $MachinePrecision] * N[Log[t], $MachinePrecision] + (-t)), $MachinePrecision]]
\begin{array}{l}

\\
\begin{array}{l}
\mathbf{if}\;t \leq 480:\\
\;\;\;\;\log z + \left(\log t \cdot \left(a - 0.5\right) + \log y\right)\\

\mathbf{else}:\\
\;\;\;\;\mathsf{fma}\left(a + -0.5, \log t, -t\right)\\


\end{array}
\end{array}
Derivation
  1. Split input into 2 regimes
  2. if t < 480

    1. Initial program 99.3%

      \[\left(\left(\log \left(x + y\right) + \log z\right) - t\right) + \left(a - 0.5\right) \cdot \log t \]
    2. Step-by-step derivation
      1. associate--l+99.3%

        \[\leadsto \color{blue}{\left(\log \left(x + y\right) + \left(\log z - t\right)\right)} + \left(a - 0.5\right) \cdot \log t \]
      2. +-commutative99.3%

        \[\leadsto \color{blue}{\left(\left(\log z - t\right) + \log \left(x + y\right)\right)} + \left(a - 0.5\right) \cdot \log t \]
      3. associate-+l+99.3%

        \[\leadsto \color{blue}{\left(\log z - t\right) + \left(\log \left(x + y\right) + \left(a - 0.5\right) \cdot \log t\right)} \]
      4. +-commutative99.3%

        \[\leadsto \left(\log z - t\right) + \color{blue}{\left(\left(a - 0.5\right) \cdot \log t + \log \left(x + y\right)\right)} \]
      5. fma-def99.3%

        \[\leadsto \left(\log z - t\right) + \color{blue}{\mathsf{fma}\left(a - 0.5, \log t, \log \left(x + y\right)\right)} \]
      6. sub-neg99.3%

        \[\leadsto \left(\log z - t\right) + \mathsf{fma}\left(\color{blue}{a + \left(-0.5\right)}, \log t, \log \left(x + y\right)\right) \]
      7. metadata-eval99.3%

        \[\leadsto \left(\log z - t\right) + \mathsf{fma}\left(a + \color{blue}{-0.5}, \log t, \log \left(x + y\right)\right) \]
    3. Simplified99.3%

      \[\leadsto \color{blue}{\left(\log z - t\right) + \mathsf{fma}\left(a + -0.5, \log t, \log \left(x + y\right)\right)} \]
    4. Taylor expanded in x around 0 62.0%

      \[\leadsto \left(\log z - t\right) + \color{blue}{\left(\left(a - 0.5\right) \cdot \log t + \log y\right)} \]
    5. Taylor expanded in t around 0 61.8%

      \[\leadsto \color{blue}{\log z} + \left(\left(a - 0.5\right) \cdot \log t + \log y\right) \]

    if 480 < t

    1. Initial program 99.8%

      \[\left(\left(\log \left(x + y\right) + \log z\right) - t\right) + \left(a - 0.5\right) \cdot \log t \]
    2. Step-by-step derivation
      1. associate--l+99.8%

        \[\leadsto \color{blue}{\left(\log \left(x + y\right) + \left(\log z - t\right)\right)} + \left(a - 0.5\right) \cdot \log t \]
      2. associate-+l+99.8%

        \[\leadsto \color{blue}{\log \left(x + y\right) + \left(\left(\log z - t\right) + \left(a - 0.5\right) \cdot \log t\right)} \]
      3. +-commutative99.8%

        \[\leadsto \log \left(x + y\right) + \color{blue}{\left(\left(a - 0.5\right) \cdot \log t + \left(\log z - t\right)\right)} \]
      4. fma-def99.8%

        \[\leadsto \log \left(x + y\right) + \color{blue}{\mathsf{fma}\left(a - 0.5, \log t, \log z - t\right)} \]
      5. remove-double-neg99.8%

        \[\leadsto \log \left(x + y\right) + \mathsf{fma}\left(\color{blue}{-\left(-\left(a - 0.5\right)\right)}, \log t, \log z - t\right) \]
      6. remove-double-neg99.8%

        \[\leadsto \log \left(x + y\right) + \mathsf{fma}\left(\color{blue}{a - 0.5}, \log t, \log z - t\right) \]
      7. sub-neg99.8%

        \[\leadsto \log \left(x + y\right) + \mathsf{fma}\left(\color{blue}{a + \left(-0.5\right)}, \log t, \log z - t\right) \]
      8. metadata-eval99.8%

        \[\leadsto \log \left(x + y\right) + \mathsf{fma}\left(a + \color{blue}{-0.5}, \log t, \log z - t\right) \]
    3. Simplified99.8%

      \[\leadsto \color{blue}{\log \left(x + y\right) + \mathsf{fma}\left(a + -0.5, \log t, \log z - t\right)} \]
    4. Step-by-step derivation
      1. +-commutative99.8%

        \[\leadsto \color{blue}{\mathsf{fma}\left(a + -0.5, \log t, \log z - t\right) + \log \left(x + y\right)} \]
      2. fma-udef99.8%

        \[\leadsto \color{blue}{\left(\left(a + -0.5\right) \cdot \log t + \left(\log z - t\right)\right)} + \log \left(x + y\right) \]
      3. associate-+r+99.8%

        \[\leadsto \color{blue}{\left(a + -0.5\right) \cdot \log t + \left(\left(\log z - t\right) + \log \left(x + y\right)\right)} \]
      4. +-commutative99.8%

        \[\leadsto \left(a + -0.5\right) \cdot \log t + \color{blue}{\left(\log \left(x + y\right) + \left(\log z - t\right)\right)} \]
      5. fma-def99.8%

        \[\leadsto \color{blue}{\mathsf{fma}\left(a + -0.5, \log t, \log \left(x + y\right) + \left(\log z - t\right)\right)} \]
      6. associate-+r-99.8%

        \[\leadsto \mathsf{fma}\left(a + -0.5, \log t, \color{blue}{\left(\log \left(x + y\right) + \log z\right) - t}\right) \]
      7. sum-log73.3%

        \[\leadsto \mathsf{fma}\left(a + -0.5, \log t, \color{blue}{\log \left(\left(x + y\right) \cdot z\right)} - t\right) \]
    5. Applied egg-rr73.3%

      \[\leadsto \color{blue}{\mathsf{fma}\left(a + -0.5, \log t, \log \left(\left(x + y\right) \cdot z\right) - t\right)} \]
    6. Taylor expanded in t around inf 99.6%

      \[\leadsto \mathsf{fma}\left(a + -0.5, \log t, \color{blue}{-1 \cdot t}\right) \]
    7. Step-by-step derivation
      1. neg-mul-199.6%

        \[\leadsto \mathsf{fma}\left(a + -0.5, \log t, \color{blue}{-t}\right) \]
    8. Simplified99.6%

      \[\leadsto \mathsf{fma}\left(a + -0.5, \log t, \color{blue}{-t}\right) \]
  3. Recombined 2 regimes into one program.
  4. Final simplification80.8%

    \[\leadsto \begin{array}{l} \mathbf{if}\;t \leq 480:\\ \;\;\;\;\log z + \left(\log t \cdot \left(a - 0.5\right) + \log y\right)\\ \mathbf{else}:\\ \;\;\;\;\mathsf{fma}\left(a + -0.5, \log t, -t\right)\\ \end{array} \]

Alternative 5: 80.4% accurate, 1.0× speedup?

\[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;t \leq 220:\\ \;\;\;\;\log t \cdot \left(a - 0.5\right) + \left(\log z + \log y\right)\\ \mathbf{else}:\\ \;\;\;\;\mathsf{fma}\left(a + -0.5, \log t, -t\right)\\ \end{array} \end{array} \]
(FPCore (x y z t a)
 :precision binary64
 (if (<= t 220.0)
   (+ (* (log t) (- a 0.5)) (+ (log z) (log y)))
   (fma (+ a -0.5) (log t) (- t))))
double code(double x, double y, double z, double t, double a) {
	double tmp;
	if (t <= 220.0) {
		tmp = (log(t) * (a - 0.5)) + (log(z) + log(y));
	} else {
		tmp = fma((a + -0.5), log(t), -t);
	}
	return tmp;
}
function code(x, y, z, t, a)
	tmp = 0.0
	if (t <= 220.0)
		tmp = Float64(Float64(log(t) * Float64(a - 0.5)) + Float64(log(z) + log(y)));
	else
		tmp = fma(Float64(a + -0.5), log(t), Float64(-t));
	end
	return tmp
end
code[x_, y_, z_, t_, a_] := If[LessEqual[t, 220.0], N[(N[(N[Log[t], $MachinePrecision] * N[(a - 0.5), $MachinePrecision]), $MachinePrecision] + N[(N[Log[z], $MachinePrecision] + N[Log[y], $MachinePrecision]), $MachinePrecision]), $MachinePrecision], N[(N[(a + -0.5), $MachinePrecision] * N[Log[t], $MachinePrecision] + (-t)), $MachinePrecision]]
\begin{array}{l}

\\
\begin{array}{l}
\mathbf{if}\;t \leq 220:\\
\;\;\;\;\log t \cdot \left(a - 0.5\right) + \left(\log z + \log y\right)\\

\mathbf{else}:\\
\;\;\;\;\mathsf{fma}\left(a + -0.5, \log t, -t\right)\\


\end{array}
\end{array}
Derivation
  1. Split input into 2 regimes
  2. if t < 220

    1. Initial program 99.3%

      \[\left(\left(\log \left(x + y\right) + \log z\right) - t\right) + \left(a - 0.5\right) \cdot \log t \]
    2. Step-by-step derivation
      1. associate--l+99.3%

        \[\leadsto \color{blue}{\left(\log \left(x + y\right) + \left(\log z - t\right)\right)} + \left(a - 0.5\right) \cdot \log t \]
      2. +-commutative99.3%

        \[\leadsto \color{blue}{\left(\left(\log z - t\right) + \log \left(x + y\right)\right)} + \left(a - 0.5\right) \cdot \log t \]
      3. associate-+l+99.3%

        \[\leadsto \color{blue}{\left(\log z - t\right) + \left(\log \left(x + y\right) + \left(a - 0.5\right) \cdot \log t\right)} \]
      4. +-commutative99.3%

        \[\leadsto \left(\log z - t\right) + \color{blue}{\left(\left(a - 0.5\right) \cdot \log t + \log \left(x + y\right)\right)} \]
      5. fma-def99.3%

        \[\leadsto \left(\log z - t\right) + \color{blue}{\mathsf{fma}\left(a - 0.5, \log t, \log \left(x + y\right)\right)} \]
      6. sub-neg99.3%

        \[\leadsto \left(\log z - t\right) + \mathsf{fma}\left(\color{blue}{a + \left(-0.5\right)}, \log t, \log \left(x + y\right)\right) \]
      7. metadata-eval99.3%

        \[\leadsto \left(\log z - t\right) + \mathsf{fma}\left(a + \color{blue}{-0.5}, \log t, \log \left(x + y\right)\right) \]
    3. Simplified99.3%

      \[\leadsto \color{blue}{\left(\log z - t\right) + \mathsf{fma}\left(a + -0.5, \log t, \log \left(x + y\right)\right)} \]
    4. Taylor expanded in x around 0 62.0%

      \[\leadsto \left(\log z - t\right) + \color{blue}{\left(\left(a - 0.5\right) \cdot \log t + \log y\right)} \]
    5. Taylor expanded in t around 0 61.8%

      \[\leadsto \color{blue}{\left(a - 0.5\right) \cdot \log t + \left(\log z + \log y\right)} \]

    if 220 < t

    1. Initial program 99.8%

      \[\left(\left(\log \left(x + y\right) + \log z\right) - t\right) + \left(a - 0.5\right) \cdot \log t \]
    2. Step-by-step derivation
      1. associate--l+99.8%

        \[\leadsto \color{blue}{\left(\log \left(x + y\right) + \left(\log z - t\right)\right)} + \left(a - 0.5\right) \cdot \log t \]
      2. associate-+l+99.8%

        \[\leadsto \color{blue}{\log \left(x + y\right) + \left(\left(\log z - t\right) + \left(a - 0.5\right) \cdot \log t\right)} \]
      3. +-commutative99.8%

        \[\leadsto \log \left(x + y\right) + \color{blue}{\left(\left(a - 0.5\right) \cdot \log t + \left(\log z - t\right)\right)} \]
      4. fma-def99.8%

        \[\leadsto \log \left(x + y\right) + \color{blue}{\mathsf{fma}\left(a - 0.5, \log t, \log z - t\right)} \]
      5. remove-double-neg99.8%

        \[\leadsto \log \left(x + y\right) + \mathsf{fma}\left(\color{blue}{-\left(-\left(a - 0.5\right)\right)}, \log t, \log z - t\right) \]
      6. remove-double-neg99.8%

        \[\leadsto \log \left(x + y\right) + \mathsf{fma}\left(\color{blue}{a - 0.5}, \log t, \log z - t\right) \]
      7. sub-neg99.8%

        \[\leadsto \log \left(x + y\right) + \mathsf{fma}\left(\color{blue}{a + \left(-0.5\right)}, \log t, \log z - t\right) \]
      8. metadata-eval99.8%

        \[\leadsto \log \left(x + y\right) + \mathsf{fma}\left(a + \color{blue}{-0.5}, \log t, \log z - t\right) \]
    3. Simplified99.8%

      \[\leadsto \color{blue}{\log \left(x + y\right) + \mathsf{fma}\left(a + -0.5, \log t, \log z - t\right)} \]
    4. Step-by-step derivation
      1. +-commutative99.8%

        \[\leadsto \color{blue}{\mathsf{fma}\left(a + -0.5, \log t, \log z - t\right) + \log \left(x + y\right)} \]
      2. fma-udef99.8%

        \[\leadsto \color{blue}{\left(\left(a + -0.5\right) \cdot \log t + \left(\log z - t\right)\right)} + \log \left(x + y\right) \]
      3. associate-+r+99.8%

        \[\leadsto \color{blue}{\left(a + -0.5\right) \cdot \log t + \left(\left(\log z - t\right) + \log \left(x + y\right)\right)} \]
      4. +-commutative99.8%

        \[\leadsto \left(a + -0.5\right) \cdot \log t + \color{blue}{\left(\log \left(x + y\right) + \left(\log z - t\right)\right)} \]
      5. fma-def99.8%

        \[\leadsto \color{blue}{\mathsf{fma}\left(a + -0.5, \log t, \log \left(x + y\right) + \left(\log z - t\right)\right)} \]
      6. associate-+r-99.8%

        \[\leadsto \mathsf{fma}\left(a + -0.5, \log t, \color{blue}{\left(\log \left(x + y\right) + \log z\right) - t}\right) \]
      7. sum-log73.3%

        \[\leadsto \mathsf{fma}\left(a + -0.5, \log t, \color{blue}{\log \left(\left(x + y\right) \cdot z\right)} - t\right) \]
    5. Applied egg-rr73.3%

      \[\leadsto \color{blue}{\mathsf{fma}\left(a + -0.5, \log t, \log \left(\left(x + y\right) \cdot z\right) - t\right)} \]
    6. Taylor expanded in t around inf 99.6%

      \[\leadsto \mathsf{fma}\left(a + -0.5, \log t, \color{blue}{-1 \cdot t}\right) \]
    7. Step-by-step derivation
      1. neg-mul-199.6%

        \[\leadsto \mathsf{fma}\left(a + -0.5, \log t, \color{blue}{-t}\right) \]
    8. Simplified99.6%

      \[\leadsto \mathsf{fma}\left(a + -0.5, \log t, \color{blue}{-t}\right) \]
  3. Recombined 2 regimes into one program.
  4. Final simplification80.8%

    \[\leadsto \begin{array}{l} \mathbf{if}\;t \leq 220:\\ \;\;\;\;\log t \cdot \left(a - 0.5\right) + \left(\log z + \log y\right)\\ \mathbf{else}:\\ \;\;\;\;\mathsf{fma}\left(a + -0.5, \log t, -t\right)\\ \end{array} \]

Alternative 6: 68.8% accurate, 1.0× speedup?

\[\begin{array}{l} \\ \left(\log z - t\right) + \left(\log t \cdot \left(a - 0.5\right) + \log y\right) \end{array} \]
(FPCore (x y z t a)
 :precision binary64
 (+ (- (log z) t) (+ (* (log t) (- a 0.5)) (log y))))
double code(double x, double y, double z, double t, double a) {
	return (log(z) - t) + ((log(t) * (a - 0.5)) + log(y));
}
real(8) function code(x, y, z, t, a)
    real(8), intent (in) :: x
    real(8), intent (in) :: y
    real(8), intent (in) :: z
    real(8), intent (in) :: t
    real(8), intent (in) :: a
    code = (log(z) - t) + ((log(t) * (a - 0.5d0)) + log(y))
end function
public static double code(double x, double y, double z, double t, double a) {
	return (Math.log(z) - t) + ((Math.log(t) * (a - 0.5)) + Math.log(y));
}
def code(x, y, z, t, a):
	return (math.log(z) - t) + ((math.log(t) * (a - 0.5)) + math.log(y))
function code(x, y, z, t, a)
	return Float64(Float64(log(z) - t) + Float64(Float64(log(t) * Float64(a - 0.5)) + log(y)))
end
function tmp = code(x, y, z, t, a)
	tmp = (log(z) - t) + ((log(t) * (a - 0.5)) + log(y));
end
code[x_, y_, z_, t_, a_] := N[(N[(N[Log[z], $MachinePrecision] - t), $MachinePrecision] + N[(N[(N[Log[t], $MachinePrecision] * N[(a - 0.5), $MachinePrecision]), $MachinePrecision] + N[Log[y], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}

\\
\left(\log z - t\right) + \left(\log t \cdot \left(a - 0.5\right) + \log y\right)
\end{array}
Derivation
  1. Initial program 99.6%

    \[\left(\left(\log \left(x + y\right) + \log z\right) - t\right) + \left(a - 0.5\right) \cdot \log t \]
  2. Step-by-step derivation
    1. associate--l+99.6%

      \[\leadsto \color{blue}{\left(\log \left(x + y\right) + \left(\log z - t\right)\right)} + \left(a - 0.5\right) \cdot \log t \]
    2. +-commutative99.6%

      \[\leadsto \color{blue}{\left(\left(\log z - t\right) + \log \left(x + y\right)\right)} + \left(a - 0.5\right) \cdot \log t \]
    3. associate-+l+99.5%

      \[\leadsto \color{blue}{\left(\log z - t\right) + \left(\log \left(x + y\right) + \left(a - 0.5\right) \cdot \log t\right)} \]
    4. +-commutative99.5%

      \[\leadsto \left(\log z - t\right) + \color{blue}{\left(\left(a - 0.5\right) \cdot \log t + \log \left(x + y\right)\right)} \]
    5. fma-def99.5%

      \[\leadsto \left(\log z - t\right) + \color{blue}{\mathsf{fma}\left(a - 0.5, \log t, \log \left(x + y\right)\right)} \]
    6. sub-neg99.5%

      \[\leadsto \left(\log z - t\right) + \mathsf{fma}\left(\color{blue}{a + \left(-0.5\right)}, \log t, \log \left(x + y\right)\right) \]
    7. metadata-eval99.5%

      \[\leadsto \left(\log z - t\right) + \mathsf{fma}\left(a + \color{blue}{-0.5}, \log t, \log \left(x + y\right)\right) \]
  3. Simplified99.5%

    \[\leadsto \color{blue}{\left(\log z - t\right) + \mathsf{fma}\left(a + -0.5, \log t, \log \left(x + y\right)\right)} \]
  4. Taylor expanded in x around 0 70.1%

    \[\leadsto \left(\log z - t\right) + \color{blue}{\left(\left(a - 0.5\right) \cdot \log t + \log y\right)} \]
  5. Final simplification70.1%

    \[\leadsto \left(\log z - t\right) + \left(\log t \cdot \left(a - 0.5\right) + \log y\right) \]

Alternative 7: 84.2% accurate, 1.4× speedup?

\[\begin{array}{l} \\ \begin{array}{l} t_1 := \left(a + -0.5\right) \cdot \log t\\ t_2 := t_1 + \log \left(z \cdot \left(x + y\right)\right)\\ \mathbf{if}\;t \leq 1.16 \cdot 10^{-142}:\\ \;\;\;\;t_2\\ \mathbf{elif}\;t \leq 10^{-109}:\\ \;\;\;\;t_1 + \log y\\ \mathbf{elif}\;t \leq 2.5 \cdot 10^{-26}:\\ \;\;\;\;t_2\\ \mathbf{else}:\\ \;\;\;\;\mathsf{fma}\left(a + -0.5, \log t, -t\right)\\ \end{array} \end{array} \]
(FPCore (x y z t a)
 :precision binary64
 (let* ((t_1 (* (+ a -0.5) (log t))) (t_2 (+ t_1 (log (* z (+ x y))))))
   (if (<= t 1.16e-142)
     t_2
     (if (<= t 1e-109)
       (+ t_1 (log y))
       (if (<= t 2.5e-26) t_2 (fma (+ a -0.5) (log t) (- t)))))))
double code(double x, double y, double z, double t, double a) {
	double t_1 = (a + -0.5) * log(t);
	double t_2 = t_1 + log((z * (x + y)));
	double tmp;
	if (t <= 1.16e-142) {
		tmp = t_2;
	} else if (t <= 1e-109) {
		tmp = t_1 + log(y);
	} else if (t <= 2.5e-26) {
		tmp = t_2;
	} else {
		tmp = fma((a + -0.5), log(t), -t);
	}
	return tmp;
}
function code(x, y, z, t, a)
	t_1 = Float64(Float64(a + -0.5) * log(t))
	t_2 = Float64(t_1 + log(Float64(z * Float64(x + y))))
	tmp = 0.0
	if (t <= 1.16e-142)
		tmp = t_2;
	elseif (t <= 1e-109)
		tmp = Float64(t_1 + log(y));
	elseif (t <= 2.5e-26)
		tmp = t_2;
	else
		tmp = fma(Float64(a + -0.5), log(t), Float64(-t));
	end
	return tmp
end
code[x_, y_, z_, t_, a_] := Block[{t$95$1 = N[(N[(a + -0.5), $MachinePrecision] * N[Log[t], $MachinePrecision]), $MachinePrecision]}, Block[{t$95$2 = N[(t$95$1 + N[Log[N[(z * N[(x + y), $MachinePrecision]), $MachinePrecision]], $MachinePrecision]), $MachinePrecision]}, If[LessEqual[t, 1.16e-142], t$95$2, If[LessEqual[t, 1e-109], N[(t$95$1 + N[Log[y], $MachinePrecision]), $MachinePrecision], If[LessEqual[t, 2.5e-26], t$95$2, N[(N[(a + -0.5), $MachinePrecision] * N[Log[t], $MachinePrecision] + (-t)), $MachinePrecision]]]]]]
\begin{array}{l}

\\
\begin{array}{l}
t_1 := \left(a + -0.5\right) \cdot \log t\\
t_2 := t_1 + \log \left(z \cdot \left(x + y\right)\right)\\
\mathbf{if}\;t \leq 1.16 \cdot 10^{-142}:\\
\;\;\;\;t_2\\

\mathbf{elif}\;t \leq 10^{-109}:\\
\;\;\;\;t_1 + \log y\\

\mathbf{elif}\;t \leq 2.5 \cdot 10^{-26}:\\
\;\;\;\;t_2\\

\mathbf{else}:\\
\;\;\;\;\mathsf{fma}\left(a + -0.5, \log t, -t\right)\\


\end{array}
\end{array}
Derivation
  1. Split input into 3 regimes
  2. if t < 1.16e-142 or 9.9999999999999999e-110 < t < 2.5000000000000001e-26

    1. Initial program 99.3%

      \[\left(\left(\log \left(x + y\right) + \log z\right) - t\right) + \left(a - 0.5\right) \cdot \log t \]
    2. Step-by-step derivation
      1. associate--l+99.3%

        \[\leadsto \color{blue}{\left(\log \left(x + y\right) + \left(\log z - t\right)\right)} + \left(a - 0.5\right) \cdot \log t \]
      2. sub-neg99.3%

        \[\leadsto \left(\log \left(x + y\right) + \left(\log z - t\right)\right) + \color{blue}{\left(a + \left(-0.5\right)\right)} \cdot \log t \]
      3. metadata-eval99.3%

        \[\leadsto \left(\log \left(x + y\right) + \left(\log z - t\right)\right) + \left(a + \color{blue}{-0.5}\right) \cdot \log t \]
    3. Simplified99.3%

      \[\leadsto \color{blue}{\left(\log \left(x + y\right) + \left(\log z - t\right)\right) + \left(a + -0.5\right) \cdot \log t} \]
    4. Taylor expanded in t around 0 99.3%

      \[\leadsto \color{blue}{\left(\log z + \log \left(y + x\right)\right)} + \left(a + -0.5\right) \cdot \log t \]
    5. Step-by-step derivation
      1. +-commutative99.3%

        \[\leadsto \left(\log z + \log \color{blue}{\left(x + y\right)}\right) + \left(a + -0.5\right) \cdot \log t \]
      2. log-prod81.1%

        \[\leadsto \color{blue}{\log \left(z \cdot \left(x + y\right)\right)} + \left(a + -0.5\right) \cdot \log t \]
      3. +-commutative81.1%

        \[\leadsto \log \left(z \cdot \color{blue}{\left(y + x\right)}\right) + \left(a + -0.5\right) \cdot \log t \]
    6. Simplified81.1%

      \[\leadsto \color{blue}{\log \left(z \cdot \left(y + x\right)\right)} + \left(a + -0.5\right) \cdot \log t \]

    if 1.16e-142 < t < 9.9999999999999999e-110

    1. Initial program 99.0%

      \[\left(\left(\log \left(x + y\right) + \log z\right) - t\right) + \left(a - 0.5\right) \cdot \log t \]
    2. Step-by-step derivation
      1. associate--l+99.0%

        \[\leadsto \color{blue}{\left(\log \left(x + y\right) + \left(\log z - t\right)\right)} + \left(a - 0.5\right) \cdot \log t \]
      2. +-commutative99.0%

        \[\leadsto \color{blue}{\left(\left(\log z - t\right) + \log \left(x + y\right)\right)} + \left(a - 0.5\right) \cdot \log t \]
      3. associate-+l+99.1%

        \[\leadsto \color{blue}{\left(\log z - t\right) + \left(\log \left(x + y\right) + \left(a - 0.5\right) \cdot \log t\right)} \]
      4. +-commutative99.1%

        \[\leadsto \left(\log z - t\right) + \color{blue}{\left(\left(a - 0.5\right) \cdot \log t + \log \left(x + y\right)\right)} \]
      5. fma-def99.1%

        \[\leadsto \left(\log z - t\right) + \color{blue}{\mathsf{fma}\left(a - 0.5, \log t, \log \left(x + y\right)\right)} \]
      6. sub-neg99.1%

        \[\leadsto \left(\log z - t\right) + \mathsf{fma}\left(\color{blue}{a + \left(-0.5\right)}, \log t, \log \left(x + y\right)\right) \]
      7. metadata-eval99.1%

        \[\leadsto \left(\log z - t\right) + \mathsf{fma}\left(a + \color{blue}{-0.5}, \log t, \log \left(x + y\right)\right) \]
    3. Simplified99.1%

      \[\leadsto \color{blue}{\left(\log z - t\right) + \mathsf{fma}\left(a + -0.5, \log t, \log \left(x + y\right)\right)} \]
    4. Taylor expanded in x around 0 79.2%

      \[\leadsto \left(\log z - t\right) + \color{blue}{\left(\left(a - 0.5\right) \cdot \log t + \log y\right)} \]
    5. Step-by-step derivation
      1. add-cube-cbrt79.2%

        \[\leadsto \color{blue}{\left(\sqrt[3]{\log z - t} \cdot \sqrt[3]{\log z - t}\right) \cdot \sqrt[3]{\log z - t}} + \left(\left(a - 0.5\right) \cdot \log t + \log y\right) \]
      2. pow379.2%

        \[\leadsto \color{blue}{{\left(\sqrt[3]{\log z - t}\right)}^{3}} + \left(\left(a - 0.5\right) \cdot \log t + \log y\right) \]
    6. Applied egg-rr79.2%

      \[\leadsto \color{blue}{{\left(\sqrt[3]{\log z - t}\right)}^{3}} + \left(\left(a - 0.5\right) \cdot \log t + \log y\right) \]
    7. Taylor expanded in t around inf 78.9%

      \[\leadsto \color{blue}{-1 \cdot \left(\log \left(\frac{1}{t}\right) \cdot \left(a - 0.5\right)\right) + \log y} \]
    8. Step-by-step derivation
      1. +-commutative78.9%

        \[\leadsto \color{blue}{\log y + -1 \cdot \left(\log \left(\frac{1}{t}\right) \cdot \left(a - 0.5\right)\right)} \]
      2. mul-1-neg78.9%

        \[\leadsto \log y + \color{blue}{\left(-\log \left(\frac{1}{t}\right) \cdot \left(a - 0.5\right)\right)} \]
      3. unsub-neg78.9%

        \[\leadsto \color{blue}{\log y - \log \left(\frac{1}{t}\right) \cdot \left(a - 0.5\right)} \]
      4. log-rec78.9%

        \[\leadsto \log y - \color{blue}{\left(-\log t\right)} \cdot \left(a - 0.5\right) \]
      5. *-commutative78.9%

        \[\leadsto \log y - \color{blue}{\left(a - 0.5\right) \cdot \left(-\log t\right)} \]
      6. sub-neg78.9%

        \[\leadsto \log y - \color{blue}{\left(a + \left(-0.5\right)\right)} \cdot \left(-\log t\right) \]
      7. metadata-eval78.9%

        \[\leadsto \log y - \left(a + \color{blue}{-0.5}\right) \cdot \left(-\log t\right) \]
    9. Simplified78.9%

      \[\leadsto \color{blue}{\log y - \left(a + -0.5\right) \cdot \left(-\log t\right)} \]

    if 2.5000000000000001e-26 < t

    1. Initial program 99.8%

      \[\left(\left(\log \left(x + y\right) + \log z\right) - t\right) + \left(a - 0.5\right) \cdot \log t \]
    2. Step-by-step derivation
      1. associate--l+99.8%

        \[\leadsto \color{blue}{\left(\log \left(x + y\right) + \left(\log z - t\right)\right)} + \left(a - 0.5\right) \cdot \log t \]
      2. associate-+l+99.8%

        \[\leadsto \color{blue}{\log \left(x + y\right) + \left(\left(\log z - t\right) + \left(a - 0.5\right) \cdot \log t\right)} \]
      3. +-commutative99.8%

        \[\leadsto \log \left(x + y\right) + \color{blue}{\left(\left(a - 0.5\right) \cdot \log t + \left(\log z - t\right)\right)} \]
      4. fma-def99.8%

        \[\leadsto \log \left(x + y\right) + \color{blue}{\mathsf{fma}\left(a - 0.5, \log t, \log z - t\right)} \]
      5. remove-double-neg99.8%

        \[\leadsto \log \left(x + y\right) + \mathsf{fma}\left(\color{blue}{-\left(-\left(a - 0.5\right)\right)}, \log t, \log z - t\right) \]
      6. remove-double-neg99.8%

        \[\leadsto \log \left(x + y\right) + \mathsf{fma}\left(\color{blue}{a - 0.5}, \log t, \log z - t\right) \]
      7. sub-neg99.8%

        \[\leadsto \log \left(x + y\right) + \mathsf{fma}\left(\color{blue}{a + \left(-0.5\right)}, \log t, \log z - t\right) \]
      8. metadata-eval99.8%

        \[\leadsto \log \left(x + y\right) + \mathsf{fma}\left(a + \color{blue}{-0.5}, \log t, \log z - t\right) \]
    3. Simplified99.8%

      \[\leadsto \color{blue}{\log \left(x + y\right) + \mathsf{fma}\left(a + -0.5, \log t, \log z - t\right)} \]
    4. Step-by-step derivation
      1. +-commutative99.8%

        \[\leadsto \color{blue}{\mathsf{fma}\left(a + -0.5, \log t, \log z - t\right) + \log \left(x + y\right)} \]
      2. fma-udef99.8%

        \[\leadsto \color{blue}{\left(\left(a + -0.5\right) \cdot \log t + \left(\log z - t\right)\right)} + \log \left(x + y\right) \]
      3. associate-+r+99.8%

        \[\leadsto \color{blue}{\left(a + -0.5\right) \cdot \log t + \left(\left(\log z - t\right) + \log \left(x + y\right)\right)} \]
      4. +-commutative99.8%

        \[\leadsto \left(a + -0.5\right) \cdot \log t + \color{blue}{\left(\log \left(x + y\right) + \left(\log z - t\right)\right)} \]
      5. fma-def99.8%

        \[\leadsto \color{blue}{\mathsf{fma}\left(a + -0.5, \log t, \log \left(x + y\right) + \left(\log z - t\right)\right)} \]
      6. associate-+r-99.8%

        \[\leadsto \mathsf{fma}\left(a + -0.5, \log t, \color{blue}{\left(\log \left(x + y\right) + \log z\right) - t}\right) \]
      7. sum-log72.0%

        \[\leadsto \mathsf{fma}\left(a + -0.5, \log t, \color{blue}{\log \left(\left(x + y\right) \cdot z\right)} - t\right) \]
    5. Applied egg-rr72.0%

      \[\leadsto \color{blue}{\mathsf{fma}\left(a + -0.5, \log t, \log \left(\left(x + y\right) \cdot z\right) - t\right)} \]
    6. Taylor expanded in t around inf 95.4%

      \[\leadsto \mathsf{fma}\left(a + -0.5, \log t, \color{blue}{-1 \cdot t}\right) \]
    7. Step-by-step derivation
      1. neg-mul-195.4%

        \[\leadsto \mathsf{fma}\left(a + -0.5, \log t, \color{blue}{-t}\right) \]
    8. Simplified95.4%

      \[\leadsto \mathsf{fma}\left(a + -0.5, \log t, \color{blue}{-t}\right) \]
  3. Recombined 3 regimes into one program.
  4. Final simplification89.0%

    \[\leadsto \begin{array}{l} \mathbf{if}\;t \leq 1.16 \cdot 10^{-142}:\\ \;\;\;\;\left(a + -0.5\right) \cdot \log t + \log \left(z \cdot \left(x + y\right)\right)\\ \mathbf{elif}\;t \leq 10^{-109}:\\ \;\;\;\;\left(a + -0.5\right) \cdot \log t + \log y\\ \mathbf{elif}\;t \leq 2.5 \cdot 10^{-26}:\\ \;\;\;\;\left(a + -0.5\right) \cdot \log t + \log \left(z \cdot \left(x + y\right)\right)\\ \mathbf{else}:\\ \;\;\;\;\mathsf{fma}\left(a + -0.5, \log t, -t\right)\\ \end{array} \]

Alternative 8: 73.6% accurate, 1.5× speedup?

\[\begin{array}{l} \\ \begin{array}{l} t_1 := \log \left(\left(y \cdot z\right) \cdot {t}^{\left(a + -0.5\right)}\right)\\ \mathbf{if}\;t \leq 1.25 \cdot 10^{-264}:\\ \;\;\;\;t_1\\ \mathbf{elif}\;t \leq 3.2 \cdot 10^{-45}:\\ \;\;\;\;\log \left(x + y\right) + a \cdot \log t\\ \mathbf{elif}\;t \leq 3.15 \cdot 10^{-27}:\\ \;\;\;\;t_1\\ \mathbf{else}:\\ \;\;\;\;\mathsf{fma}\left(a + -0.5, \log t, -t\right)\\ \end{array} \end{array} \]
(FPCore (x y z t a)
 :precision binary64
 (let* ((t_1 (log (* (* y z) (pow t (+ a -0.5))))))
   (if (<= t 1.25e-264)
     t_1
     (if (<= t 3.2e-45)
       (+ (log (+ x y)) (* a (log t)))
       (if (<= t 3.15e-27) t_1 (fma (+ a -0.5) (log t) (- t)))))))
double code(double x, double y, double z, double t, double a) {
	double t_1 = log(((y * z) * pow(t, (a + -0.5))));
	double tmp;
	if (t <= 1.25e-264) {
		tmp = t_1;
	} else if (t <= 3.2e-45) {
		tmp = log((x + y)) + (a * log(t));
	} else if (t <= 3.15e-27) {
		tmp = t_1;
	} else {
		tmp = fma((a + -0.5), log(t), -t);
	}
	return tmp;
}
function code(x, y, z, t, a)
	t_1 = log(Float64(Float64(y * z) * (t ^ Float64(a + -0.5))))
	tmp = 0.0
	if (t <= 1.25e-264)
		tmp = t_1;
	elseif (t <= 3.2e-45)
		tmp = Float64(log(Float64(x + y)) + Float64(a * log(t)));
	elseif (t <= 3.15e-27)
		tmp = t_1;
	else
		tmp = fma(Float64(a + -0.5), log(t), Float64(-t));
	end
	return tmp
end
code[x_, y_, z_, t_, a_] := Block[{t$95$1 = N[Log[N[(N[(y * z), $MachinePrecision] * N[Power[t, N[(a + -0.5), $MachinePrecision]], $MachinePrecision]), $MachinePrecision]], $MachinePrecision]}, If[LessEqual[t, 1.25e-264], t$95$1, If[LessEqual[t, 3.2e-45], N[(N[Log[N[(x + y), $MachinePrecision]], $MachinePrecision] + N[(a * N[Log[t], $MachinePrecision]), $MachinePrecision]), $MachinePrecision], If[LessEqual[t, 3.15e-27], t$95$1, N[(N[(a + -0.5), $MachinePrecision] * N[Log[t], $MachinePrecision] + (-t)), $MachinePrecision]]]]]
\begin{array}{l}

\\
\begin{array}{l}
t_1 := \log \left(\left(y \cdot z\right) \cdot {t}^{\left(a + -0.5\right)}\right)\\
\mathbf{if}\;t \leq 1.25 \cdot 10^{-264}:\\
\;\;\;\;t_1\\

\mathbf{elif}\;t \leq 3.2 \cdot 10^{-45}:\\
\;\;\;\;\log \left(x + y\right) + a \cdot \log t\\

\mathbf{elif}\;t \leq 3.15 \cdot 10^{-27}:\\
\;\;\;\;t_1\\

\mathbf{else}:\\
\;\;\;\;\mathsf{fma}\left(a + -0.5, \log t, -t\right)\\


\end{array}
\end{array}
Derivation
  1. Split input into 3 regimes
  2. if t < 1.25e-264 or 3.20000000000000007e-45 < t < 3.15000000000000005e-27

    1. Initial program 99.2%

      \[\left(\left(\log \left(x + y\right) + \log z\right) - t\right) + \left(a - 0.5\right) \cdot \log t \]
    2. Step-by-step derivation
      1. associate--l+99.2%

        \[\leadsto \color{blue}{\left(\log \left(x + y\right) + \left(\log z - t\right)\right)} + \left(a - 0.5\right) \cdot \log t \]
      2. +-commutative99.2%

        \[\leadsto \color{blue}{\left(\left(\log z - t\right) + \log \left(x + y\right)\right)} + \left(a - 0.5\right) \cdot \log t \]
      3. associate-+l+99.2%

        \[\leadsto \color{blue}{\left(\log z - t\right) + \left(\log \left(x + y\right) + \left(a - 0.5\right) \cdot \log t\right)} \]
      4. +-commutative99.2%

        \[\leadsto \left(\log z - t\right) + \color{blue}{\left(\left(a - 0.5\right) \cdot \log t + \log \left(x + y\right)\right)} \]
      5. fma-def99.2%

        \[\leadsto \left(\log z - t\right) + \color{blue}{\mathsf{fma}\left(a - 0.5, \log t, \log \left(x + y\right)\right)} \]
      6. sub-neg99.2%

        \[\leadsto \left(\log z - t\right) + \mathsf{fma}\left(\color{blue}{a + \left(-0.5\right)}, \log t, \log \left(x + y\right)\right) \]
      7. metadata-eval99.2%

        \[\leadsto \left(\log z - t\right) + \mathsf{fma}\left(a + \color{blue}{-0.5}, \log t, \log \left(x + y\right)\right) \]
    3. Simplified99.2%

      \[\leadsto \color{blue}{\left(\log z - t\right) + \mathsf{fma}\left(a + -0.5, \log t, \log \left(x + y\right)\right)} \]
    4. Taylor expanded in x around 0 57.0%

      \[\leadsto \left(\log z - t\right) + \color{blue}{\left(\left(a - 0.5\right) \cdot \log t + \log y\right)} \]
    5. Step-by-step derivation
      1. add-cube-cbrt56.5%

        \[\leadsto \color{blue}{\left(\sqrt[3]{\log z - t} \cdot \sqrt[3]{\log z - t}\right) \cdot \sqrt[3]{\log z - t}} + \left(\left(a - 0.5\right) \cdot \log t + \log y\right) \]
      2. pow356.4%

        \[\leadsto \color{blue}{{\left(\sqrt[3]{\log z - t}\right)}^{3}} + \left(\left(a - 0.5\right) \cdot \log t + \log y\right) \]
    6. Applied egg-rr56.4%

      \[\leadsto \color{blue}{{\left(\sqrt[3]{\log z - t}\right)}^{3}} + \left(\left(a - 0.5\right) \cdot \log t + \log y\right) \]
    7. Taylor expanded in t around 0 57.1%

      \[\leadsto \color{blue}{\left(a - 0.5\right) \cdot \log t + \left({1}^{0.3333333333333333} \cdot \log z + \log y\right)} \]
    8. Step-by-step derivation
      1. +-commutative57.1%

        \[\leadsto \color{blue}{\left({1}^{0.3333333333333333} \cdot \log z + \log y\right) + \left(a - 0.5\right) \cdot \log t} \]
      2. +-commutative57.1%

        \[\leadsto \color{blue}{\left(\log y + {1}^{0.3333333333333333} \cdot \log z\right)} + \left(a - 0.5\right) \cdot \log t \]
      3. pow-base-157.1%

        \[\leadsto \left(\log y + \color{blue}{1} \cdot \log z\right) + \left(a - 0.5\right) \cdot \log t \]
      4. *-lft-identity57.1%

        \[\leadsto \left(\log y + \color{blue}{\log z}\right) + \left(a - 0.5\right) \cdot \log t \]
      5. log-prod48.9%

        \[\leadsto \color{blue}{\log \left(y \cdot z\right)} + \left(a - 0.5\right) \cdot \log t \]
      6. log-pow45.5%

        \[\leadsto \log \left(y \cdot z\right) + \color{blue}{\log \left({t}^{\left(a - 0.5\right)}\right)} \]
      7. log-prod38.5%

        \[\leadsto \color{blue}{\log \left(\left(y \cdot z\right) \cdot {t}^{\left(a - 0.5\right)}\right)} \]
      8. sub-neg38.5%

        \[\leadsto \log \left(\left(y \cdot z\right) \cdot {t}^{\color{blue}{\left(a + \left(-0.5\right)\right)}}\right) \]
      9. metadata-eval38.5%

        \[\leadsto \log \left(\left(y \cdot z\right) \cdot {t}^{\left(a + \color{blue}{-0.5}\right)}\right) \]
    9. Simplified38.5%

      \[\leadsto \color{blue}{\log \left(\left(y \cdot z\right) \cdot {t}^{\left(a + -0.5\right)}\right)} \]

    if 1.25e-264 < t < 3.20000000000000007e-45

    1. Initial program 99.3%

      \[\left(\left(\log \left(x + y\right) + \log z\right) - t\right) + \left(a - 0.5\right) \cdot \log t \]
    2. Step-by-step derivation
      1. associate--l+99.3%

        \[\leadsto \color{blue}{\left(\log \left(x + y\right) + \left(\log z - t\right)\right)} + \left(a - 0.5\right) \cdot \log t \]
      2. associate-+l+99.3%

        \[\leadsto \color{blue}{\log \left(x + y\right) + \left(\left(\log z - t\right) + \left(a - 0.5\right) \cdot \log t\right)} \]
      3. +-commutative99.3%

        \[\leadsto \log \left(x + y\right) + \color{blue}{\left(\left(a - 0.5\right) \cdot \log t + \left(\log z - t\right)\right)} \]
      4. fma-def99.3%

        \[\leadsto \log \left(x + y\right) + \color{blue}{\mathsf{fma}\left(a - 0.5, \log t, \log z - t\right)} \]
      5. remove-double-neg99.3%

        \[\leadsto \log \left(x + y\right) + \mathsf{fma}\left(\color{blue}{-\left(-\left(a - 0.5\right)\right)}, \log t, \log z - t\right) \]
      6. remove-double-neg99.3%

        \[\leadsto \log \left(x + y\right) + \mathsf{fma}\left(\color{blue}{a - 0.5}, \log t, \log z - t\right) \]
      7. sub-neg99.3%

        \[\leadsto \log \left(x + y\right) + \mathsf{fma}\left(\color{blue}{a + \left(-0.5\right)}, \log t, \log z - t\right) \]
      8. metadata-eval99.3%

        \[\leadsto \log \left(x + y\right) + \mathsf{fma}\left(a + \color{blue}{-0.5}, \log t, \log z - t\right) \]
    3. Simplified99.3%

      \[\leadsto \color{blue}{\log \left(x + y\right) + \mathsf{fma}\left(a + -0.5, \log t, \log z - t\right)} \]
    4. Taylor expanded in a around inf 61.5%

      \[\leadsto \log \left(x + y\right) + \color{blue}{a \cdot \log t} \]
    5. Step-by-step derivation
      1. *-commutative61.5%

        \[\leadsto \log \left(x + y\right) + \color{blue}{\log t \cdot a} \]
    6. Simplified61.5%

      \[\leadsto \log \left(x + y\right) + \color{blue}{\log t \cdot a} \]

    if 3.15000000000000005e-27 < t

    1. Initial program 99.8%

      \[\left(\left(\log \left(x + y\right) + \log z\right) - t\right) + \left(a - 0.5\right) \cdot \log t \]
    2. Step-by-step derivation
      1. associate--l+99.8%

        \[\leadsto \color{blue}{\left(\log \left(x + y\right) + \left(\log z - t\right)\right)} + \left(a - 0.5\right) \cdot \log t \]
      2. associate-+l+99.8%

        \[\leadsto \color{blue}{\log \left(x + y\right) + \left(\left(\log z - t\right) + \left(a - 0.5\right) \cdot \log t\right)} \]
      3. +-commutative99.8%

        \[\leadsto \log \left(x + y\right) + \color{blue}{\left(\left(a - 0.5\right) \cdot \log t + \left(\log z - t\right)\right)} \]
      4. fma-def99.8%

        \[\leadsto \log \left(x + y\right) + \color{blue}{\mathsf{fma}\left(a - 0.5, \log t, \log z - t\right)} \]
      5. remove-double-neg99.8%

        \[\leadsto \log \left(x + y\right) + \mathsf{fma}\left(\color{blue}{-\left(-\left(a - 0.5\right)\right)}, \log t, \log z - t\right) \]
      6. remove-double-neg99.8%

        \[\leadsto \log \left(x + y\right) + \mathsf{fma}\left(\color{blue}{a - 0.5}, \log t, \log z - t\right) \]
      7. sub-neg99.8%

        \[\leadsto \log \left(x + y\right) + \mathsf{fma}\left(\color{blue}{a + \left(-0.5\right)}, \log t, \log z - t\right) \]
      8. metadata-eval99.8%

        \[\leadsto \log \left(x + y\right) + \mathsf{fma}\left(a + \color{blue}{-0.5}, \log t, \log z - t\right) \]
    3. Simplified99.8%

      \[\leadsto \color{blue}{\log \left(x + y\right) + \mathsf{fma}\left(a + -0.5, \log t, \log z - t\right)} \]
    4. Step-by-step derivation
      1. +-commutative99.8%

        \[\leadsto \color{blue}{\mathsf{fma}\left(a + -0.5, \log t, \log z - t\right) + \log \left(x + y\right)} \]
      2. fma-udef99.8%

        \[\leadsto \color{blue}{\left(\left(a + -0.5\right) \cdot \log t + \left(\log z - t\right)\right)} + \log \left(x + y\right) \]
      3. associate-+r+99.8%

        \[\leadsto \color{blue}{\left(a + -0.5\right) \cdot \log t + \left(\left(\log z - t\right) + \log \left(x + y\right)\right)} \]
      4. +-commutative99.8%

        \[\leadsto \left(a + -0.5\right) \cdot \log t + \color{blue}{\left(\log \left(x + y\right) + \left(\log z - t\right)\right)} \]
      5. fma-def99.8%

        \[\leadsto \color{blue}{\mathsf{fma}\left(a + -0.5, \log t, \log \left(x + y\right) + \left(\log z - t\right)\right)} \]
      6. associate-+r-99.8%

        \[\leadsto \mathsf{fma}\left(a + -0.5, \log t, \color{blue}{\left(\log \left(x + y\right) + \log z\right) - t}\right) \]
      7. sum-log72.0%

        \[\leadsto \mathsf{fma}\left(a + -0.5, \log t, \color{blue}{\log \left(\left(x + y\right) \cdot z\right)} - t\right) \]
    5. Applied egg-rr72.0%

      \[\leadsto \color{blue}{\mathsf{fma}\left(a + -0.5, \log t, \log \left(\left(x + y\right) \cdot z\right) - t\right)} \]
    6. Taylor expanded in t around inf 95.4%

      \[\leadsto \mathsf{fma}\left(a + -0.5, \log t, \color{blue}{-1 \cdot t}\right) \]
    7. Step-by-step derivation
      1. neg-mul-195.4%

        \[\leadsto \mathsf{fma}\left(a + -0.5, \log t, \color{blue}{-t}\right) \]
    8. Simplified95.4%

      \[\leadsto \mathsf{fma}\left(a + -0.5, \log t, \color{blue}{-t}\right) \]
  3. Recombined 3 regimes into one program.
  4. Final simplification77.9%

    \[\leadsto \begin{array}{l} \mathbf{if}\;t \leq 1.25 \cdot 10^{-264}:\\ \;\;\;\;\log \left(\left(y \cdot z\right) \cdot {t}^{\left(a + -0.5\right)}\right)\\ \mathbf{elif}\;t \leq 3.2 \cdot 10^{-45}:\\ \;\;\;\;\log \left(x + y\right) + a \cdot \log t\\ \mathbf{elif}\;t \leq 3.15 \cdot 10^{-27}:\\ \;\;\;\;\log \left(\left(y \cdot z\right) \cdot {t}^{\left(a + -0.5\right)}\right)\\ \mathbf{else}:\\ \;\;\;\;\mathsf{fma}\left(a + -0.5, \log t, -t\right)\\ \end{array} \]

Alternative 9: 73.1% accurate, 1.5× speedup?

\[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;a \leq -9.2 \cdot 10^{-8} \lor \neg \left(a \leq 4.8 \cdot 10^{-18}\right):\\ \;\;\;\;\mathsf{fma}\left(a + -0.5, \log t, -t\right)\\ \mathbf{else}:\\ \;\;\;\;\left(\log \left(y \cdot z\right) + -0.5 \cdot \log t\right) - t\\ \end{array} \end{array} \]
(FPCore (x y z t a)
 :precision binary64
 (if (or (<= a -9.2e-8) (not (<= a 4.8e-18)))
   (fma (+ a -0.5) (log t) (- t))
   (- (+ (log (* y z)) (* -0.5 (log t))) t)))
double code(double x, double y, double z, double t, double a) {
	double tmp;
	if ((a <= -9.2e-8) || !(a <= 4.8e-18)) {
		tmp = fma((a + -0.5), log(t), -t);
	} else {
		tmp = (log((y * z)) + (-0.5 * log(t))) - t;
	}
	return tmp;
}
function code(x, y, z, t, a)
	tmp = 0.0
	if ((a <= -9.2e-8) || !(a <= 4.8e-18))
		tmp = fma(Float64(a + -0.5), log(t), Float64(-t));
	else
		tmp = Float64(Float64(log(Float64(y * z)) + Float64(-0.5 * log(t))) - t);
	end
	return tmp
end
code[x_, y_, z_, t_, a_] := If[Or[LessEqual[a, -9.2e-8], N[Not[LessEqual[a, 4.8e-18]], $MachinePrecision]], N[(N[(a + -0.5), $MachinePrecision] * N[Log[t], $MachinePrecision] + (-t)), $MachinePrecision], N[(N[(N[Log[N[(y * z), $MachinePrecision]], $MachinePrecision] + N[(-0.5 * N[Log[t], $MachinePrecision]), $MachinePrecision]), $MachinePrecision] - t), $MachinePrecision]]
\begin{array}{l}

\\
\begin{array}{l}
\mathbf{if}\;a \leq -9.2 \cdot 10^{-8} \lor \neg \left(a \leq 4.8 \cdot 10^{-18}\right):\\
\;\;\;\;\mathsf{fma}\left(a + -0.5, \log t, -t\right)\\

\mathbf{else}:\\
\;\;\;\;\left(\log \left(y \cdot z\right) + -0.5 \cdot \log t\right) - t\\


\end{array}
\end{array}
Derivation
  1. Split input into 2 regimes
  2. if a < -9.2000000000000003e-8 or 4.79999999999999988e-18 < a

    1. Initial program 99.5%

      \[\left(\left(\log \left(x + y\right) + \log z\right) - t\right) + \left(a - 0.5\right) \cdot \log t \]
    2. Step-by-step derivation
      1. associate--l+99.5%

        \[\leadsto \color{blue}{\left(\log \left(x + y\right) + \left(\log z - t\right)\right)} + \left(a - 0.5\right) \cdot \log t \]
      2. associate-+l+99.5%

        \[\leadsto \color{blue}{\log \left(x + y\right) + \left(\left(\log z - t\right) + \left(a - 0.5\right) \cdot \log t\right)} \]
      3. +-commutative99.5%

        \[\leadsto \log \left(x + y\right) + \color{blue}{\left(\left(a - 0.5\right) \cdot \log t + \left(\log z - t\right)\right)} \]
      4. fma-def99.6%

        \[\leadsto \log \left(x + y\right) + \color{blue}{\mathsf{fma}\left(a - 0.5, \log t, \log z - t\right)} \]
      5. remove-double-neg99.6%

        \[\leadsto \log \left(x + y\right) + \mathsf{fma}\left(\color{blue}{-\left(-\left(a - 0.5\right)\right)}, \log t, \log z - t\right) \]
      6. remove-double-neg99.6%

        \[\leadsto \log \left(x + y\right) + \mathsf{fma}\left(\color{blue}{a - 0.5}, \log t, \log z - t\right) \]
      7. sub-neg99.6%

        \[\leadsto \log \left(x + y\right) + \mathsf{fma}\left(\color{blue}{a + \left(-0.5\right)}, \log t, \log z - t\right) \]
      8. metadata-eval99.6%

        \[\leadsto \log \left(x + y\right) + \mathsf{fma}\left(a + \color{blue}{-0.5}, \log t, \log z - t\right) \]
    3. Simplified99.6%

      \[\leadsto \color{blue}{\log \left(x + y\right) + \mathsf{fma}\left(a + -0.5, \log t, \log z - t\right)} \]
    4. Step-by-step derivation
      1. +-commutative99.6%

        \[\leadsto \color{blue}{\mathsf{fma}\left(a + -0.5, \log t, \log z - t\right) + \log \left(x + y\right)} \]
      2. fma-udef99.5%

        \[\leadsto \color{blue}{\left(\left(a + -0.5\right) \cdot \log t + \left(\log z - t\right)\right)} + \log \left(x + y\right) \]
      3. associate-+r+99.5%

        \[\leadsto \color{blue}{\left(a + -0.5\right) \cdot \log t + \left(\left(\log z - t\right) + \log \left(x + y\right)\right)} \]
      4. +-commutative99.5%

        \[\leadsto \left(a + -0.5\right) \cdot \log t + \color{blue}{\left(\log \left(x + y\right) + \left(\log z - t\right)\right)} \]
      5. fma-def99.5%

        \[\leadsto \color{blue}{\mathsf{fma}\left(a + -0.5, \log t, \log \left(x + y\right) + \left(\log z - t\right)\right)} \]
      6. associate-+r-99.5%

        \[\leadsto \mathsf{fma}\left(a + -0.5, \log t, \color{blue}{\left(\log \left(x + y\right) + \log z\right) - t}\right) \]
      7. sum-log74.6%

        \[\leadsto \mathsf{fma}\left(a + -0.5, \log t, \color{blue}{\log \left(\left(x + y\right) \cdot z\right)} - t\right) \]
    5. Applied egg-rr74.6%

      \[\leadsto \color{blue}{\mathsf{fma}\left(a + -0.5, \log t, \log \left(\left(x + y\right) \cdot z\right) - t\right)} \]
    6. Taylor expanded in t around inf 96.5%

      \[\leadsto \mathsf{fma}\left(a + -0.5, \log t, \color{blue}{-1 \cdot t}\right) \]
    7. Step-by-step derivation
      1. neg-mul-196.5%

        \[\leadsto \mathsf{fma}\left(a + -0.5, \log t, \color{blue}{-t}\right) \]
    8. Simplified96.5%

      \[\leadsto \mathsf{fma}\left(a + -0.5, \log t, \color{blue}{-t}\right) \]

    if -9.2000000000000003e-8 < a < 4.79999999999999988e-18

    1. Initial program 99.6%

      \[\left(\left(\log \left(x + y\right) + \log z\right) - t\right) + \left(a - 0.5\right) \cdot \log t \]
    2. Step-by-step derivation
      1. associate--l+99.6%

        \[\leadsto \color{blue}{\left(\log \left(x + y\right) + \left(\log z - t\right)\right)} + \left(a - 0.5\right) \cdot \log t \]
      2. +-commutative99.6%

        \[\leadsto \color{blue}{\left(\left(\log z - t\right) + \log \left(x + y\right)\right)} + \left(a - 0.5\right) \cdot \log t \]
      3. associate-+l+99.5%

        \[\leadsto \color{blue}{\left(\log z - t\right) + \left(\log \left(x + y\right) + \left(a - 0.5\right) \cdot \log t\right)} \]
      4. +-commutative99.5%

        \[\leadsto \left(\log z - t\right) + \color{blue}{\left(\left(a - 0.5\right) \cdot \log t + \log \left(x + y\right)\right)} \]
      5. fma-def99.5%

        \[\leadsto \left(\log z - t\right) + \color{blue}{\mathsf{fma}\left(a - 0.5, \log t, \log \left(x + y\right)\right)} \]
      6. sub-neg99.5%

        \[\leadsto \left(\log z - t\right) + \mathsf{fma}\left(\color{blue}{a + \left(-0.5\right)}, \log t, \log \left(x + y\right)\right) \]
      7. metadata-eval99.5%

        \[\leadsto \left(\log z - t\right) + \mathsf{fma}\left(a + \color{blue}{-0.5}, \log t, \log \left(x + y\right)\right) \]
    3. Simplified99.5%

      \[\leadsto \color{blue}{\left(\log z - t\right) + \mathsf{fma}\left(a + -0.5, \log t, \log \left(x + y\right)\right)} \]
    4. Taylor expanded in x around 0 69.3%

      \[\leadsto \left(\log z - t\right) + \color{blue}{\left(\left(a - 0.5\right) \cdot \log t + \log y\right)} \]
    5. Taylor expanded in a around 0 69.3%

      \[\leadsto \color{blue}{\left(\log z + \left(\log y + -0.5 \cdot \log t\right)\right) - t} \]
    6. Step-by-step derivation
      1. associate-+r+69.3%

        \[\leadsto \color{blue}{\left(\left(\log z + \log y\right) + -0.5 \cdot \log t\right)} - t \]
      2. log-prod57.6%

        \[\leadsto \left(\color{blue}{\log \left(z \cdot y\right)} + -0.5 \cdot \log t\right) - t \]
      3. *-commutative57.6%

        \[\leadsto \left(\log \left(z \cdot y\right) + \color{blue}{\log t \cdot -0.5}\right) - t \]
    7. Simplified57.6%

      \[\leadsto \color{blue}{\left(\log \left(z \cdot y\right) + \log t \cdot -0.5\right) - t} \]
  3. Recombined 2 regimes into one program.
  4. Final simplification77.7%

    \[\leadsto \begin{array}{l} \mathbf{if}\;a \leq -9.2 \cdot 10^{-8} \lor \neg \left(a \leq 4.8 \cdot 10^{-18}\right):\\ \;\;\;\;\mathsf{fma}\left(a + -0.5, \log t, -t\right)\\ \mathbf{else}:\\ \;\;\;\;\left(\log \left(y \cdot z\right) + -0.5 \cdot \log t\right) - t\\ \end{array} \]

Alternative 10: 66.2% accurate, 1.5× speedup?

\[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;z \leq 2.4 \cdot 10^{+75}:\\ \;\;\;\;\left(\log t \cdot \left(a - 0.5\right) + \log \left(y \cdot z\right)\right) - t\\ \mathbf{else}:\\ \;\;\;\;\mathsf{fma}\left(a + -0.5, \log t, -t\right)\\ \end{array} \end{array} \]
(FPCore (x y z t a)
 :precision binary64
 (if (<= z 2.4e+75)
   (- (+ (* (log t) (- a 0.5)) (log (* y z))) t)
   (fma (+ a -0.5) (log t) (- t))))
double code(double x, double y, double z, double t, double a) {
	double tmp;
	if (z <= 2.4e+75) {
		tmp = ((log(t) * (a - 0.5)) + log((y * z))) - t;
	} else {
		tmp = fma((a + -0.5), log(t), -t);
	}
	return tmp;
}
function code(x, y, z, t, a)
	tmp = 0.0
	if (z <= 2.4e+75)
		tmp = Float64(Float64(Float64(log(t) * Float64(a - 0.5)) + log(Float64(y * z))) - t);
	else
		tmp = fma(Float64(a + -0.5), log(t), Float64(-t));
	end
	return tmp
end
code[x_, y_, z_, t_, a_] := If[LessEqual[z, 2.4e+75], N[(N[(N[(N[Log[t], $MachinePrecision] * N[(a - 0.5), $MachinePrecision]), $MachinePrecision] + N[Log[N[(y * z), $MachinePrecision]], $MachinePrecision]), $MachinePrecision] - t), $MachinePrecision], N[(N[(a + -0.5), $MachinePrecision] * N[Log[t], $MachinePrecision] + (-t)), $MachinePrecision]]
\begin{array}{l}

\\
\begin{array}{l}
\mathbf{if}\;z \leq 2.4 \cdot 10^{+75}:\\
\;\;\;\;\left(\log t \cdot \left(a - 0.5\right) + \log \left(y \cdot z\right)\right) - t\\

\mathbf{else}:\\
\;\;\;\;\mathsf{fma}\left(a + -0.5, \log t, -t\right)\\


\end{array}
\end{array}
Derivation
  1. Split input into 2 regimes
  2. if z < 2.4e75

    1. Initial program 99.5%

      \[\left(\left(\log \left(x + y\right) + \log z\right) - t\right) + \left(a - 0.5\right) \cdot \log t \]
    2. Step-by-step derivation
      1. associate--l+99.6%

        \[\leadsto \color{blue}{\left(\log \left(x + y\right) + \left(\log z - t\right)\right)} + \left(a - 0.5\right) \cdot \log t \]
      2. associate-+l+99.6%

        \[\leadsto \color{blue}{\log \left(x + y\right) + \left(\left(\log z - t\right) + \left(a - 0.5\right) \cdot \log t\right)} \]
      3. +-commutative99.6%

        \[\leadsto \log \left(x + y\right) + \color{blue}{\left(\left(a - 0.5\right) \cdot \log t + \left(\log z - t\right)\right)} \]
      4. fma-def99.6%

        \[\leadsto \log \left(x + y\right) + \color{blue}{\mathsf{fma}\left(a - 0.5, \log t, \log z - t\right)} \]
      5. remove-double-neg99.6%

        \[\leadsto \log \left(x + y\right) + \mathsf{fma}\left(\color{blue}{-\left(-\left(a - 0.5\right)\right)}, \log t, \log z - t\right) \]
      6. remove-double-neg99.6%

        \[\leadsto \log \left(x + y\right) + \mathsf{fma}\left(\color{blue}{a - 0.5}, \log t, \log z - t\right) \]
      7. sub-neg99.6%

        \[\leadsto \log \left(x + y\right) + \mathsf{fma}\left(\color{blue}{a + \left(-0.5\right)}, \log t, \log z - t\right) \]
      8. metadata-eval99.6%

        \[\leadsto \log \left(x + y\right) + \mathsf{fma}\left(a + \color{blue}{-0.5}, \log t, \log z - t\right) \]
    3. Simplified99.6%

      \[\leadsto \color{blue}{\log \left(x + y\right) + \mathsf{fma}\left(a + -0.5, \log t, \log z - t\right)} \]
    4. Step-by-step derivation
      1. add-sqr-sqrt37.2%

        \[\leadsto \color{blue}{\sqrt{\log \left(x + y\right) + \mathsf{fma}\left(a + -0.5, \log t, \log z - t\right)} \cdot \sqrt{\log \left(x + y\right) + \mathsf{fma}\left(a + -0.5, \log t, \log z - t\right)}} \]
      2. pow237.2%

        \[\leadsto \color{blue}{{\left(\sqrt{\log \left(x + y\right) + \mathsf{fma}\left(a + -0.5, \log t, \log z - t\right)}\right)}^{2}} \]
      3. +-commutative37.2%

        \[\leadsto {\left(\sqrt{\color{blue}{\mathsf{fma}\left(a + -0.5, \log t, \log z - t\right) + \log \left(x + y\right)}}\right)}^{2} \]
      4. fma-udef37.2%

        \[\leadsto {\left(\sqrt{\color{blue}{\left(\left(a + -0.5\right) \cdot \log t + \left(\log z - t\right)\right)} + \log \left(x + y\right)}\right)}^{2} \]
      5. associate-+r+37.2%

        \[\leadsto {\left(\sqrt{\color{blue}{\left(a + -0.5\right) \cdot \log t + \left(\left(\log z - t\right) + \log \left(x + y\right)\right)}}\right)}^{2} \]
      6. +-commutative37.2%

        \[\leadsto {\left(\sqrt{\left(a + -0.5\right) \cdot \log t + \color{blue}{\left(\log \left(x + y\right) + \left(\log z - t\right)\right)}}\right)}^{2} \]
      7. fma-def37.2%

        \[\leadsto {\left(\sqrt{\color{blue}{\mathsf{fma}\left(a + -0.5, \log t, \log \left(x + y\right) + \left(\log z - t\right)\right)}}\right)}^{2} \]
      8. associate-+r-37.2%

        \[\leadsto {\left(\sqrt{\mathsf{fma}\left(a + -0.5, \log t, \color{blue}{\left(\log \left(x + y\right) + \log z\right) - t}\right)}\right)}^{2} \]
      9. sum-log34.8%

        \[\leadsto {\left(\sqrt{\mathsf{fma}\left(a + -0.5, \log t, \color{blue}{\log \left(\left(x + y\right) \cdot z\right)} - t\right)}\right)}^{2} \]
    5. Applied egg-rr34.8%

      \[\leadsto \color{blue}{{\left(\sqrt{\mathsf{fma}\left(a + -0.5, \log t, \log \left(\left(x + y\right) \cdot z\right) - t\right)}\right)}^{2}} \]
    6. Taylor expanded in x around 0 58.8%

      \[\leadsto \color{blue}{\left(\log \left(y \cdot z\right) + \left(a - 0.5\right) \cdot \log t\right) - t} \]

    if 2.4e75 < z

    1. Initial program 99.6%

      \[\left(\left(\log \left(x + y\right) + \log z\right) - t\right) + \left(a - 0.5\right) \cdot \log t \]
    2. Step-by-step derivation
      1. associate--l+99.6%

        \[\leadsto \color{blue}{\left(\log \left(x + y\right) + \left(\log z - t\right)\right)} + \left(a - 0.5\right) \cdot \log t \]
      2. associate-+l+99.6%

        \[\leadsto \color{blue}{\log \left(x + y\right) + \left(\left(\log z - t\right) + \left(a - 0.5\right) \cdot \log t\right)} \]
      3. +-commutative99.6%

        \[\leadsto \log \left(x + y\right) + \color{blue}{\left(\left(a - 0.5\right) \cdot \log t + \left(\log z - t\right)\right)} \]
      4. fma-def99.6%

        \[\leadsto \log \left(x + y\right) + \color{blue}{\mathsf{fma}\left(a - 0.5, \log t, \log z - t\right)} \]
      5. remove-double-neg99.6%

        \[\leadsto \log \left(x + y\right) + \mathsf{fma}\left(\color{blue}{-\left(-\left(a - 0.5\right)\right)}, \log t, \log z - t\right) \]
      6. remove-double-neg99.6%

        \[\leadsto \log \left(x + y\right) + \mathsf{fma}\left(\color{blue}{a - 0.5}, \log t, \log z - t\right) \]
      7. sub-neg99.6%

        \[\leadsto \log \left(x + y\right) + \mathsf{fma}\left(\color{blue}{a + \left(-0.5\right)}, \log t, \log z - t\right) \]
      8. metadata-eval99.6%

        \[\leadsto \log \left(x + y\right) + \mathsf{fma}\left(a + \color{blue}{-0.5}, \log t, \log z - t\right) \]
    3. Simplified99.6%

      \[\leadsto \color{blue}{\log \left(x + y\right) + \mathsf{fma}\left(a + -0.5, \log t, \log z - t\right)} \]
    4. Step-by-step derivation
      1. +-commutative99.6%

        \[\leadsto \color{blue}{\mathsf{fma}\left(a + -0.5, \log t, \log z - t\right) + \log \left(x + y\right)} \]
      2. fma-udef99.6%

        \[\leadsto \color{blue}{\left(\left(a + -0.5\right) \cdot \log t + \left(\log z - t\right)\right)} + \log \left(x + y\right) \]
      3. associate-+r+99.6%

        \[\leadsto \color{blue}{\left(a + -0.5\right) \cdot \log t + \left(\left(\log z - t\right) + \log \left(x + y\right)\right)} \]
      4. +-commutative99.6%

        \[\leadsto \left(a + -0.5\right) \cdot \log t + \color{blue}{\left(\log \left(x + y\right) + \left(\log z - t\right)\right)} \]
      5. fma-def99.6%

        \[\leadsto \color{blue}{\mathsf{fma}\left(a + -0.5, \log t, \log \left(x + y\right) + \left(\log z - t\right)\right)} \]
      6. associate-+r-99.6%

        \[\leadsto \mathsf{fma}\left(a + -0.5, \log t, \color{blue}{\left(\log \left(x + y\right) + \log z\right) - t}\right) \]
      7. sum-log46.1%

        \[\leadsto \mathsf{fma}\left(a + -0.5, \log t, \color{blue}{\log \left(\left(x + y\right) \cdot z\right)} - t\right) \]
    5. Applied egg-rr46.1%

      \[\leadsto \color{blue}{\mathsf{fma}\left(a + -0.5, \log t, \log \left(\left(x + y\right) \cdot z\right) - t\right)} \]
    6. Taylor expanded in t around inf 82.0%

      \[\leadsto \mathsf{fma}\left(a + -0.5, \log t, \color{blue}{-1 \cdot t}\right) \]
    7. Step-by-step derivation
      1. neg-mul-182.0%

        \[\leadsto \mathsf{fma}\left(a + -0.5, \log t, \color{blue}{-t}\right) \]
    8. Simplified82.0%

      \[\leadsto \mathsf{fma}\left(a + -0.5, \log t, \color{blue}{-t}\right) \]
  3. Recombined 2 regimes into one program.
  4. Final simplification68.0%

    \[\leadsto \begin{array}{l} \mathbf{if}\;z \leq 2.4 \cdot 10^{+75}:\\ \;\;\;\;\left(\log t \cdot \left(a - 0.5\right) + \log \left(y \cdot z\right)\right) - t\\ \mathbf{else}:\\ \;\;\;\;\mathsf{fma}\left(a + -0.5, \log t, -t\right)\\ \end{array} \]

Alternative 11: 73.0% accurate, 1.5× speedup?

\[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;a \leq -1.9 \cdot 10^{-160} \lor \neg \left(a \leq 4 \cdot 10^{-18}\right):\\ \;\;\;\;\mathsf{fma}\left(a + -0.5, \log t, -t\right)\\ \mathbf{else}:\\ \;\;\;\;\log \left(y \cdot \left(z \cdot {t}^{-0.5}\right)\right) - t\\ \end{array} \end{array} \]
(FPCore (x y z t a)
 :precision binary64
 (if (or (<= a -1.9e-160) (not (<= a 4e-18)))
   (fma (+ a -0.5) (log t) (- t))
   (- (log (* y (* z (pow t -0.5)))) t)))
double code(double x, double y, double z, double t, double a) {
	double tmp;
	if ((a <= -1.9e-160) || !(a <= 4e-18)) {
		tmp = fma((a + -0.5), log(t), -t);
	} else {
		tmp = log((y * (z * pow(t, -0.5)))) - t;
	}
	return tmp;
}
function code(x, y, z, t, a)
	tmp = 0.0
	if ((a <= -1.9e-160) || !(a <= 4e-18))
		tmp = fma(Float64(a + -0.5), log(t), Float64(-t));
	else
		tmp = Float64(log(Float64(y * Float64(z * (t ^ -0.5)))) - t);
	end
	return tmp
end
code[x_, y_, z_, t_, a_] := If[Or[LessEqual[a, -1.9e-160], N[Not[LessEqual[a, 4e-18]], $MachinePrecision]], N[(N[(a + -0.5), $MachinePrecision] * N[Log[t], $MachinePrecision] + (-t)), $MachinePrecision], N[(N[Log[N[(y * N[(z * N[Power[t, -0.5], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]], $MachinePrecision] - t), $MachinePrecision]]
\begin{array}{l}

\\
\begin{array}{l}
\mathbf{if}\;a \leq -1.9 \cdot 10^{-160} \lor \neg \left(a \leq 4 \cdot 10^{-18}\right):\\
\;\;\;\;\mathsf{fma}\left(a + -0.5, \log t, -t\right)\\

\mathbf{else}:\\
\;\;\;\;\log \left(y \cdot \left(z \cdot {t}^{-0.5}\right)\right) - t\\


\end{array}
\end{array}
Derivation
  1. Split input into 2 regimes
  2. if a < -1.8999999999999999e-160 or 4.0000000000000003e-18 < a

    1. Initial program 99.5%

      \[\left(\left(\log \left(x + y\right) + \log z\right) - t\right) + \left(a - 0.5\right) \cdot \log t \]
    2. Step-by-step derivation
      1. associate--l+99.5%

        \[\leadsto \color{blue}{\left(\log \left(x + y\right) + \left(\log z - t\right)\right)} + \left(a - 0.5\right) \cdot \log t \]
      2. associate-+l+99.6%

        \[\leadsto \color{blue}{\log \left(x + y\right) + \left(\left(\log z - t\right) + \left(a - 0.5\right) \cdot \log t\right)} \]
      3. +-commutative99.6%

        \[\leadsto \log \left(x + y\right) + \color{blue}{\left(\left(a - 0.5\right) \cdot \log t + \left(\log z - t\right)\right)} \]
      4. fma-def99.6%

        \[\leadsto \log \left(x + y\right) + \color{blue}{\mathsf{fma}\left(a - 0.5, \log t, \log z - t\right)} \]
      5. remove-double-neg99.6%

        \[\leadsto \log \left(x + y\right) + \mathsf{fma}\left(\color{blue}{-\left(-\left(a - 0.5\right)\right)}, \log t, \log z - t\right) \]
      6. remove-double-neg99.6%

        \[\leadsto \log \left(x + y\right) + \mathsf{fma}\left(\color{blue}{a - 0.5}, \log t, \log z - t\right) \]
      7. sub-neg99.6%

        \[\leadsto \log \left(x + y\right) + \mathsf{fma}\left(\color{blue}{a + \left(-0.5\right)}, \log t, \log z - t\right) \]
      8. metadata-eval99.6%

        \[\leadsto \log \left(x + y\right) + \mathsf{fma}\left(a + \color{blue}{-0.5}, \log t, \log z - t\right) \]
    3. Simplified99.6%

      \[\leadsto \color{blue}{\log \left(x + y\right) + \mathsf{fma}\left(a + -0.5, \log t, \log z - t\right)} \]
    4. Step-by-step derivation
      1. +-commutative99.6%

        \[\leadsto \color{blue}{\mathsf{fma}\left(a + -0.5, \log t, \log z - t\right) + \log \left(x + y\right)} \]
      2. fma-udef99.6%

        \[\leadsto \color{blue}{\left(\left(a + -0.5\right) \cdot \log t + \left(\log z - t\right)\right)} + \log \left(x + y\right) \]
      3. associate-+r+99.5%

        \[\leadsto \color{blue}{\left(a + -0.5\right) \cdot \log t + \left(\left(\log z - t\right) + \log \left(x + y\right)\right)} \]
      4. +-commutative99.5%

        \[\leadsto \left(a + -0.5\right) \cdot \log t + \color{blue}{\left(\log \left(x + y\right) + \left(\log z - t\right)\right)} \]
      5. fma-def99.5%

        \[\leadsto \color{blue}{\mathsf{fma}\left(a + -0.5, \log t, \log \left(x + y\right) + \left(\log z - t\right)\right)} \]
      6. associate-+r-99.5%

        \[\leadsto \mathsf{fma}\left(a + -0.5, \log t, \color{blue}{\left(\log \left(x + y\right) + \log z\right) - t}\right) \]
      7. sum-log73.3%

        \[\leadsto \mathsf{fma}\left(a + -0.5, \log t, \color{blue}{\log \left(\left(x + y\right) \cdot z\right)} - t\right) \]
    5. Applied egg-rr73.3%

      \[\leadsto \color{blue}{\mathsf{fma}\left(a + -0.5, \log t, \log \left(\left(x + y\right) \cdot z\right) - t\right)} \]
    6. Taylor expanded in t around inf 91.3%

      \[\leadsto \mathsf{fma}\left(a + -0.5, \log t, \color{blue}{-1 \cdot t}\right) \]
    7. Step-by-step derivation
      1. neg-mul-191.3%

        \[\leadsto \mathsf{fma}\left(a + -0.5, \log t, \color{blue}{-t}\right) \]
    8. Simplified91.3%

      \[\leadsto \mathsf{fma}\left(a + -0.5, \log t, \color{blue}{-t}\right) \]

    if -1.8999999999999999e-160 < a < 4.0000000000000003e-18

    1. Initial program 99.6%

      \[\left(\left(\log \left(x + y\right) + \log z\right) - t\right) + \left(a - 0.5\right) \cdot \log t \]
    2. Step-by-step derivation
      1. associate--l+99.6%

        \[\leadsto \color{blue}{\left(\log \left(x + y\right) + \left(\log z - t\right)\right)} + \left(a - 0.5\right) \cdot \log t \]
      2. +-commutative99.6%

        \[\leadsto \color{blue}{\left(\left(\log z - t\right) + \log \left(x + y\right)\right)} + \left(a - 0.5\right) \cdot \log t \]
      3. associate-+l+99.5%

        \[\leadsto \color{blue}{\left(\log z - t\right) + \left(\log \left(x + y\right) + \left(a - 0.5\right) \cdot \log t\right)} \]
      4. +-commutative99.5%

        \[\leadsto \left(\log z - t\right) + \color{blue}{\left(\left(a - 0.5\right) \cdot \log t + \log \left(x + y\right)\right)} \]
      5. fma-def99.5%

        \[\leadsto \left(\log z - t\right) + \color{blue}{\mathsf{fma}\left(a - 0.5, \log t, \log \left(x + y\right)\right)} \]
      6. sub-neg99.5%

        \[\leadsto \left(\log z - t\right) + \mathsf{fma}\left(\color{blue}{a + \left(-0.5\right)}, \log t, \log \left(x + y\right)\right) \]
      7. metadata-eval99.5%

        \[\leadsto \left(\log z - t\right) + \mathsf{fma}\left(a + \color{blue}{-0.5}, \log t, \log \left(x + y\right)\right) \]
    3. Simplified99.5%

      \[\leadsto \color{blue}{\left(\log z - t\right) + \mathsf{fma}\left(a + -0.5, \log t, \log \left(x + y\right)\right)} \]
    4. Taylor expanded in x around 0 69.0%

      \[\leadsto \left(\log z - t\right) + \color{blue}{\left(\left(a - 0.5\right) \cdot \log t + \log y\right)} \]
    5. Taylor expanded in a around 0 69.0%

      \[\leadsto \color{blue}{\left(\log z + \left(\log y + -0.5 \cdot \log t\right)\right) - t} \]
    6. Step-by-step derivation
      1. associate-+r+69.0%

        \[\leadsto \color{blue}{\left(\left(\log z + \log y\right) + -0.5 \cdot \log t\right)} - t \]
      2. log-prod58.8%

        \[\leadsto \left(\color{blue}{\log \left(z \cdot y\right)} + -0.5 \cdot \log t\right) - t \]
      3. *-commutative58.8%

        \[\leadsto \left(\log \left(z \cdot y\right) + \color{blue}{\log t \cdot -0.5}\right) - t \]
    7. Simplified58.8%

      \[\leadsto \color{blue}{\left(\log \left(z \cdot y\right) + \log t \cdot -0.5\right) - t} \]
    8. Taylor expanded in z around 0 69.0%

      \[\leadsto \color{blue}{\left(\log z + \left(\log y + -0.5 \cdot \log t\right)\right)} - t \]
    9. Step-by-step derivation
      1. associate-+r+69.0%

        \[\leadsto \color{blue}{\left(\left(\log z + \log y\right) + -0.5 \cdot \log t\right)} - t \]
      2. +-commutative69.0%

        \[\leadsto \left(\color{blue}{\left(\log y + \log z\right)} + -0.5 \cdot \log t\right) - t \]
      3. log-prod58.8%

        \[\leadsto \left(\color{blue}{\log \left(y \cdot z\right)} + -0.5 \cdot \log t\right) - t \]
      4. log-pow58.8%

        \[\leadsto \left(\log \left(y \cdot z\right) + \color{blue}{\log \left({t}^{-0.5}\right)}\right) - t \]
      5. log-prod53.8%

        \[\leadsto \color{blue}{\log \left(\left(y \cdot z\right) \cdot {t}^{-0.5}\right)} - t \]
      6. associate-*l*55.7%

        \[\leadsto \log \color{blue}{\left(y \cdot \left(z \cdot {t}^{-0.5}\right)\right)} - t \]
    10. Simplified55.7%

      \[\leadsto \color{blue}{\log \left(y \cdot \left(z \cdot {t}^{-0.5}\right)\right)} - t \]
  3. Recombined 2 regimes into one program.
  4. Final simplification76.9%

    \[\leadsto \begin{array}{l} \mathbf{if}\;a \leq -1.9 \cdot 10^{-160} \lor \neg \left(a \leq 4 \cdot 10^{-18}\right):\\ \;\;\;\;\mathsf{fma}\left(a + -0.5, \log t, -t\right)\\ \mathbf{else}:\\ \;\;\;\;\log \left(y \cdot \left(z \cdot {t}^{-0.5}\right)\right) - t\\ \end{array} \]

Alternative 12: 77.2% accurate, 1.5× speedup?

\[\begin{array}{l} \\ \mathsf{fma}\left(a + -0.5, \log t, -t\right) \end{array} \]
(FPCore (x y z t a) :precision binary64 (fma (+ a -0.5) (log t) (- t)))
double code(double x, double y, double z, double t, double a) {
	return fma((a + -0.5), log(t), -t);
}
function code(x, y, z, t, a)
	return fma(Float64(a + -0.5), log(t), Float64(-t))
end
code[x_, y_, z_, t_, a_] := N[(N[(a + -0.5), $MachinePrecision] * N[Log[t], $MachinePrecision] + (-t)), $MachinePrecision]
\begin{array}{l}

\\
\mathsf{fma}\left(a + -0.5, \log t, -t\right)
\end{array}
Derivation
  1. Initial program 99.6%

    \[\left(\left(\log \left(x + y\right) + \log z\right) - t\right) + \left(a - 0.5\right) \cdot \log t \]
  2. Step-by-step derivation
    1. associate--l+99.6%

      \[\leadsto \color{blue}{\left(\log \left(x + y\right) + \left(\log z - t\right)\right)} + \left(a - 0.5\right) \cdot \log t \]
    2. associate-+l+99.6%

      \[\leadsto \color{blue}{\log \left(x + y\right) + \left(\left(\log z - t\right) + \left(a - 0.5\right) \cdot \log t\right)} \]
    3. +-commutative99.6%

      \[\leadsto \log \left(x + y\right) + \color{blue}{\left(\left(a - 0.5\right) \cdot \log t + \left(\log z - t\right)\right)} \]
    4. fma-def99.6%

      \[\leadsto \log \left(x + y\right) + \color{blue}{\mathsf{fma}\left(a - 0.5, \log t, \log z - t\right)} \]
    5. remove-double-neg99.6%

      \[\leadsto \log \left(x + y\right) + \mathsf{fma}\left(\color{blue}{-\left(-\left(a - 0.5\right)\right)}, \log t, \log z - t\right) \]
    6. remove-double-neg99.6%

      \[\leadsto \log \left(x + y\right) + \mathsf{fma}\left(\color{blue}{a - 0.5}, \log t, \log z - t\right) \]
    7. sub-neg99.6%

      \[\leadsto \log \left(x + y\right) + \mathsf{fma}\left(\color{blue}{a + \left(-0.5\right)}, \log t, \log z - t\right) \]
    8. metadata-eval99.6%

      \[\leadsto \log \left(x + y\right) + \mathsf{fma}\left(a + \color{blue}{-0.5}, \log t, \log z - t\right) \]
  3. Simplified99.6%

    \[\leadsto \color{blue}{\log \left(x + y\right) + \mathsf{fma}\left(a + -0.5, \log t, \log z - t\right)} \]
  4. Step-by-step derivation
    1. +-commutative99.6%

      \[\leadsto \color{blue}{\mathsf{fma}\left(a + -0.5, \log t, \log z - t\right) + \log \left(x + y\right)} \]
    2. fma-udef99.6%

      \[\leadsto \color{blue}{\left(\left(a + -0.5\right) \cdot \log t + \left(\log z - t\right)\right)} + \log \left(x + y\right) \]
    3. associate-+r+99.6%

      \[\leadsto \color{blue}{\left(a + -0.5\right) \cdot \log t + \left(\left(\log z - t\right) + \log \left(x + y\right)\right)} \]
    4. +-commutative99.6%

      \[\leadsto \left(a + -0.5\right) \cdot \log t + \color{blue}{\left(\log \left(x + y\right) + \left(\log z - t\right)\right)} \]
    5. fma-def99.6%

      \[\leadsto \color{blue}{\mathsf{fma}\left(a + -0.5, \log t, \log \left(x + y\right) + \left(\log z - t\right)\right)} \]
    6. associate-+r-99.6%

      \[\leadsto \mathsf{fma}\left(a + -0.5, \log t, \color{blue}{\left(\log \left(x + y\right) + \log z\right) - t}\right) \]
    7. sum-log74.7%

      \[\leadsto \mathsf{fma}\left(a + -0.5, \log t, \color{blue}{\log \left(\left(x + y\right) \cdot z\right)} - t\right) \]
  5. Applied egg-rr74.7%

    \[\leadsto \color{blue}{\mathsf{fma}\left(a + -0.5, \log t, \log \left(\left(x + y\right) \cdot z\right) - t\right)} \]
  6. Taylor expanded in t around inf 75.9%

    \[\leadsto \mathsf{fma}\left(a + -0.5, \log t, \color{blue}{-1 \cdot t}\right) \]
  7. Step-by-step derivation
    1. neg-mul-175.9%

      \[\leadsto \mathsf{fma}\left(a + -0.5, \log t, \color{blue}{-t}\right) \]
  8. Simplified75.9%

    \[\leadsto \mathsf{fma}\left(a + -0.5, \log t, \color{blue}{-t}\right) \]
  9. Final simplification75.9%

    \[\leadsto \mathsf{fma}\left(a + -0.5, \log t, -t\right) \]

Alternative 13: 56.6% accurate, 2.8× speedup?

\[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;a \leq -5.4 \cdot 10^{+53}:\\ \;\;\;\;a \cdot \log t\\ \mathbf{elif}\;a \leq 7.8 \cdot 10^{+72}:\\ \;\;\;\;\log y - t\\ \mathbf{else}:\\ \;\;\;\;\log \left(\frac{1}{t}\right) \cdot \left(-a\right)\\ \end{array} \end{array} \]
(FPCore (x y z t a)
 :precision binary64
 (if (<= a -5.4e+53)
   (* a (log t))
   (if (<= a 7.8e+72) (- (log y) t) (* (log (/ 1.0 t)) (- a)))))
double code(double x, double y, double z, double t, double a) {
	double tmp;
	if (a <= -5.4e+53) {
		tmp = a * log(t);
	} else if (a <= 7.8e+72) {
		tmp = log(y) - t;
	} else {
		tmp = log((1.0 / t)) * -a;
	}
	return tmp;
}
real(8) function code(x, y, z, t, a)
    real(8), intent (in) :: x
    real(8), intent (in) :: y
    real(8), intent (in) :: z
    real(8), intent (in) :: t
    real(8), intent (in) :: a
    real(8) :: tmp
    if (a <= (-5.4d+53)) then
        tmp = a * log(t)
    else if (a <= 7.8d+72) then
        tmp = log(y) - t
    else
        tmp = log((1.0d0 / t)) * -a
    end if
    code = tmp
end function
public static double code(double x, double y, double z, double t, double a) {
	double tmp;
	if (a <= -5.4e+53) {
		tmp = a * Math.log(t);
	} else if (a <= 7.8e+72) {
		tmp = Math.log(y) - t;
	} else {
		tmp = Math.log((1.0 / t)) * -a;
	}
	return tmp;
}
def code(x, y, z, t, a):
	tmp = 0
	if a <= -5.4e+53:
		tmp = a * math.log(t)
	elif a <= 7.8e+72:
		tmp = math.log(y) - t
	else:
		tmp = math.log((1.0 / t)) * -a
	return tmp
function code(x, y, z, t, a)
	tmp = 0.0
	if (a <= -5.4e+53)
		tmp = Float64(a * log(t));
	elseif (a <= 7.8e+72)
		tmp = Float64(log(y) - t);
	else
		tmp = Float64(log(Float64(1.0 / t)) * Float64(-a));
	end
	return tmp
end
function tmp_2 = code(x, y, z, t, a)
	tmp = 0.0;
	if (a <= -5.4e+53)
		tmp = a * log(t);
	elseif (a <= 7.8e+72)
		tmp = log(y) - t;
	else
		tmp = log((1.0 / t)) * -a;
	end
	tmp_2 = tmp;
end
code[x_, y_, z_, t_, a_] := If[LessEqual[a, -5.4e+53], N[(a * N[Log[t], $MachinePrecision]), $MachinePrecision], If[LessEqual[a, 7.8e+72], N[(N[Log[y], $MachinePrecision] - t), $MachinePrecision], N[(N[Log[N[(1.0 / t), $MachinePrecision]], $MachinePrecision] * (-a)), $MachinePrecision]]]
\begin{array}{l}

\\
\begin{array}{l}
\mathbf{if}\;a \leq -5.4 \cdot 10^{+53}:\\
\;\;\;\;a \cdot \log t\\

\mathbf{elif}\;a \leq 7.8 \cdot 10^{+72}:\\
\;\;\;\;\log y - t\\

\mathbf{else}:\\
\;\;\;\;\log \left(\frac{1}{t}\right) \cdot \left(-a\right)\\


\end{array}
\end{array}
Derivation
  1. Split input into 3 regimes
  2. if a < -5.40000000000000039e53

    1. Initial program 99.5%

      \[\left(\left(\log \left(x + y\right) + \log z\right) - t\right) + \left(a - 0.5\right) \cdot \log t \]
    2. Step-by-step derivation
      1. associate--l+99.5%

        \[\leadsto \color{blue}{\left(\log \left(x + y\right) + \left(\log z - t\right)\right)} + \left(a - 0.5\right) \cdot \log t \]
      2. +-commutative99.5%

        \[\leadsto \color{blue}{\left(\left(\log z - t\right) + \log \left(x + y\right)\right)} + \left(a - 0.5\right) \cdot \log t \]
      3. associate-+l+99.5%

        \[\leadsto \color{blue}{\left(\log z - t\right) + \left(\log \left(x + y\right) + \left(a - 0.5\right) \cdot \log t\right)} \]
      4. +-commutative99.5%

        \[\leadsto \left(\log z - t\right) + \color{blue}{\left(\left(a - 0.5\right) \cdot \log t + \log \left(x + y\right)\right)} \]
      5. fma-def99.5%

        \[\leadsto \left(\log z - t\right) + \color{blue}{\mathsf{fma}\left(a - 0.5, \log t, \log \left(x + y\right)\right)} \]
      6. sub-neg99.5%

        \[\leadsto \left(\log z - t\right) + \mathsf{fma}\left(\color{blue}{a + \left(-0.5\right)}, \log t, \log \left(x + y\right)\right) \]
      7. metadata-eval99.5%

        \[\leadsto \left(\log z - t\right) + \mathsf{fma}\left(a + \color{blue}{-0.5}, \log t, \log \left(x + y\right)\right) \]
    3. Simplified99.5%

      \[\leadsto \color{blue}{\left(\log z - t\right) + \mathsf{fma}\left(a + -0.5, \log t, \log \left(x + y\right)\right)} \]
    4. Taylor expanded in t around inf 99.5%

      \[\leadsto \left(\log z - t\right) + \color{blue}{\left(-1 \cdot \left(\log \left(\frac{1}{t}\right) \cdot \left(a - 0.5\right)\right) + \log \left(y + x\right)\right)} \]
    5. Taylor expanded in a around inf 87.7%

      \[\leadsto \color{blue}{-1 \cdot \left(a \cdot \log \left(\frac{1}{t}\right)\right)} \]
    6. Step-by-step derivation
      1. mul-1-neg87.7%

        \[\leadsto \color{blue}{-a \cdot \log \left(\frac{1}{t}\right)} \]
      2. log-rec87.7%

        \[\leadsto -a \cdot \color{blue}{\left(-\log t\right)} \]
      3. distribute-rgt-neg-in87.7%

        \[\leadsto \color{blue}{a \cdot \left(-\left(-\log t\right)\right)} \]
      4. remove-double-neg87.7%

        \[\leadsto a \cdot \color{blue}{\log t} \]
    7. Simplified87.7%

      \[\leadsto \color{blue}{a \cdot \log t} \]

    if -5.40000000000000039e53 < a < 7.79999999999999984e72

    1. Initial program 99.6%

      \[\left(\left(\log \left(x + y\right) + \log z\right) - t\right) + \left(a - 0.5\right) \cdot \log t \]
    2. Step-by-step derivation
      1. associate--l+99.6%

        \[\leadsto \color{blue}{\left(\log \left(x + y\right) + \left(\log z - t\right)\right)} + \left(a - 0.5\right) \cdot \log t \]
      2. associate-+l+99.6%

        \[\leadsto \color{blue}{\log \left(x + y\right) + \left(\left(\log z - t\right) + \left(a - 0.5\right) \cdot \log t\right)} \]
      3. +-commutative99.6%

        \[\leadsto \log \left(x + y\right) + \color{blue}{\left(\left(a - 0.5\right) \cdot \log t + \left(\log z - t\right)\right)} \]
      4. fma-def99.6%

        \[\leadsto \log \left(x + y\right) + \color{blue}{\mathsf{fma}\left(a - 0.5, \log t, \log z - t\right)} \]
      5. remove-double-neg99.6%

        \[\leadsto \log \left(x + y\right) + \mathsf{fma}\left(\color{blue}{-\left(-\left(a - 0.5\right)\right)}, \log t, \log z - t\right) \]
      6. remove-double-neg99.6%

        \[\leadsto \log \left(x + y\right) + \mathsf{fma}\left(\color{blue}{a - 0.5}, \log t, \log z - t\right) \]
      7. sub-neg99.6%

        \[\leadsto \log \left(x + y\right) + \mathsf{fma}\left(\color{blue}{a + \left(-0.5\right)}, \log t, \log z - t\right) \]
      8. metadata-eval99.6%

        \[\leadsto \log \left(x + y\right) + \mathsf{fma}\left(a + \color{blue}{-0.5}, \log t, \log z - t\right) \]
    3. Simplified99.6%

      \[\leadsto \color{blue}{\log \left(x + y\right) + \mathsf{fma}\left(a + -0.5, \log t, \log z - t\right)} \]
    4. Taylor expanded in t around inf 55.9%

      \[\leadsto \log \left(x + y\right) + \color{blue}{-1 \cdot t} \]
    5. Step-by-step derivation
      1. neg-mul-155.9%

        \[\leadsto \log \left(x + y\right) + \color{blue}{\left(-t\right)} \]
    6. Simplified55.9%

      \[\leadsto \log \left(x + y\right) + \color{blue}{\left(-t\right)} \]
    7. Taylor expanded in x around 0 43.8%

      \[\leadsto \color{blue}{\log y - t} \]

    if 7.79999999999999984e72 < a

    1. Initial program 99.4%

      \[\left(\left(\log \left(x + y\right) + \log z\right) - t\right) + \left(a - 0.5\right) \cdot \log t \]
    2. Step-by-step derivation
      1. associate--l+99.4%

        \[\leadsto \color{blue}{\left(\log \left(x + y\right) + \left(\log z - t\right)\right)} + \left(a - 0.5\right) \cdot \log t \]
      2. +-commutative99.4%

        \[\leadsto \color{blue}{\left(\left(\log z - t\right) + \log \left(x + y\right)\right)} + \left(a - 0.5\right) \cdot \log t \]
      3. associate-+l+99.4%

        \[\leadsto \color{blue}{\left(\log z - t\right) + \left(\log \left(x + y\right) + \left(a - 0.5\right) \cdot \log t\right)} \]
      4. +-commutative99.4%

        \[\leadsto \left(\log z - t\right) + \color{blue}{\left(\left(a - 0.5\right) \cdot \log t + \log \left(x + y\right)\right)} \]
      5. fma-def99.4%

        \[\leadsto \left(\log z - t\right) + \color{blue}{\mathsf{fma}\left(a - 0.5, \log t, \log \left(x + y\right)\right)} \]
      6. sub-neg99.4%

        \[\leadsto \left(\log z - t\right) + \mathsf{fma}\left(\color{blue}{a + \left(-0.5\right)}, \log t, \log \left(x + y\right)\right) \]
      7. metadata-eval99.4%

        \[\leadsto \left(\log z - t\right) + \mathsf{fma}\left(a + \color{blue}{-0.5}, \log t, \log \left(x + y\right)\right) \]
    3. Simplified99.4%

      \[\leadsto \color{blue}{\left(\log z - t\right) + \mathsf{fma}\left(a + -0.5, \log t, \log \left(x + y\right)\right)} \]
    4. Taylor expanded in t around inf 99.4%

      \[\leadsto \left(\log z - t\right) + \color{blue}{\left(-1 \cdot \left(\log \left(\frac{1}{t}\right) \cdot \left(a - 0.5\right)\right) + \log \left(y + x\right)\right)} \]
    5. Taylor expanded in a around inf 74.9%

      \[\leadsto \color{blue}{-1 \cdot \left(a \cdot \log \left(\frac{1}{t}\right)\right)} \]
  3. Recombined 3 regimes into one program.
  4. Final simplification58.8%

    \[\leadsto \begin{array}{l} \mathbf{if}\;a \leq -5.4 \cdot 10^{+53}:\\ \;\;\;\;a \cdot \log t\\ \mathbf{elif}\;a \leq 7.8 \cdot 10^{+72}:\\ \;\;\;\;\log y - t\\ \mathbf{else}:\\ \;\;\;\;\log \left(\frac{1}{t}\right) \cdot \left(-a\right)\\ \end{array} \]

Alternative 14: 56.6% accurate, 2.9× speedup?

\[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;a \leq -1.22 \cdot 10^{+54} \lor \neg \left(a \leq 7.8 \cdot 10^{+72}\right):\\ \;\;\;\;a \cdot \log t\\ \mathbf{else}:\\ \;\;\;\;\log y - t\\ \end{array} \end{array} \]
(FPCore (x y z t a)
 :precision binary64
 (if (or (<= a -1.22e+54) (not (<= a 7.8e+72))) (* a (log t)) (- (log y) t)))
double code(double x, double y, double z, double t, double a) {
	double tmp;
	if ((a <= -1.22e+54) || !(a <= 7.8e+72)) {
		tmp = a * log(t);
	} else {
		tmp = log(y) - t;
	}
	return tmp;
}
real(8) function code(x, y, z, t, a)
    real(8), intent (in) :: x
    real(8), intent (in) :: y
    real(8), intent (in) :: z
    real(8), intent (in) :: t
    real(8), intent (in) :: a
    real(8) :: tmp
    if ((a <= (-1.22d+54)) .or. (.not. (a <= 7.8d+72))) then
        tmp = a * log(t)
    else
        tmp = log(y) - t
    end if
    code = tmp
end function
public static double code(double x, double y, double z, double t, double a) {
	double tmp;
	if ((a <= -1.22e+54) || !(a <= 7.8e+72)) {
		tmp = a * Math.log(t);
	} else {
		tmp = Math.log(y) - t;
	}
	return tmp;
}
def code(x, y, z, t, a):
	tmp = 0
	if (a <= -1.22e+54) or not (a <= 7.8e+72):
		tmp = a * math.log(t)
	else:
		tmp = math.log(y) - t
	return tmp
function code(x, y, z, t, a)
	tmp = 0.0
	if ((a <= -1.22e+54) || !(a <= 7.8e+72))
		tmp = Float64(a * log(t));
	else
		tmp = Float64(log(y) - t);
	end
	return tmp
end
function tmp_2 = code(x, y, z, t, a)
	tmp = 0.0;
	if ((a <= -1.22e+54) || ~((a <= 7.8e+72)))
		tmp = a * log(t);
	else
		tmp = log(y) - t;
	end
	tmp_2 = tmp;
end
code[x_, y_, z_, t_, a_] := If[Or[LessEqual[a, -1.22e+54], N[Not[LessEqual[a, 7.8e+72]], $MachinePrecision]], N[(a * N[Log[t], $MachinePrecision]), $MachinePrecision], N[(N[Log[y], $MachinePrecision] - t), $MachinePrecision]]
\begin{array}{l}

\\
\begin{array}{l}
\mathbf{if}\;a \leq -1.22 \cdot 10^{+54} \lor \neg \left(a \leq 7.8 \cdot 10^{+72}\right):\\
\;\;\;\;a \cdot \log t\\

\mathbf{else}:\\
\;\;\;\;\log y - t\\


\end{array}
\end{array}
Derivation
  1. Split input into 2 regimes
  2. if a < -1.22e54 or 7.79999999999999984e72 < a

    1. Initial program 99.4%

      \[\left(\left(\log \left(x + y\right) + \log z\right) - t\right) + \left(a - 0.5\right) \cdot \log t \]
    2. Step-by-step derivation
      1. associate--l+99.4%

        \[\leadsto \color{blue}{\left(\log \left(x + y\right) + \left(\log z - t\right)\right)} + \left(a - 0.5\right) \cdot \log t \]
      2. +-commutative99.4%

        \[\leadsto \color{blue}{\left(\left(\log z - t\right) + \log \left(x + y\right)\right)} + \left(a - 0.5\right) \cdot \log t \]
      3. associate-+l+99.4%

        \[\leadsto \color{blue}{\left(\log z - t\right) + \left(\log \left(x + y\right) + \left(a - 0.5\right) \cdot \log t\right)} \]
      4. +-commutative99.4%

        \[\leadsto \left(\log z - t\right) + \color{blue}{\left(\left(a - 0.5\right) \cdot \log t + \log \left(x + y\right)\right)} \]
      5. fma-def99.4%

        \[\leadsto \left(\log z - t\right) + \color{blue}{\mathsf{fma}\left(a - 0.5, \log t, \log \left(x + y\right)\right)} \]
      6. sub-neg99.4%

        \[\leadsto \left(\log z - t\right) + \mathsf{fma}\left(\color{blue}{a + \left(-0.5\right)}, \log t, \log \left(x + y\right)\right) \]
      7. metadata-eval99.4%

        \[\leadsto \left(\log z - t\right) + \mathsf{fma}\left(a + \color{blue}{-0.5}, \log t, \log \left(x + y\right)\right) \]
    3. Simplified99.4%

      \[\leadsto \color{blue}{\left(\log z - t\right) + \mathsf{fma}\left(a + -0.5, \log t, \log \left(x + y\right)\right)} \]
    4. Taylor expanded in t around inf 99.5%

      \[\leadsto \left(\log z - t\right) + \color{blue}{\left(-1 \cdot \left(\log \left(\frac{1}{t}\right) \cdot \left(a - 0.5\right)\right) + \log \left(y + x\right)\right)} \]
    5. Taylor expanded in a around inf 81.8%

      \[\leadsto \color{blue}{-1 \cdot \left(a \cdot \log \left(\frac{1}{t}\right)\right)} \]
    6. Step-by-step derivation
      1. mul-1-neg81.8%

        \[\leadsto \color{blue}{-a \cdot \log \left(\frac{1}{t}\right)} \]
      2. log-rec81.7%

        \[\leadsto -a \cdot \color{blue}{\left(-\log t\right)} \]
      3. distribute-rgt-neg-in81.7%

        \[\leadsto \color{blue}{a \cdot \left(-\left(-\log t\right)\right)} \]
      4. remove-double-neg81.7%

        \[\leadsto a \cdot \color{blue}{\log t} \]
    7. Simplified81.7%

      \[\leadsto \color{blue}{a \cdot \log t} \]

    if -1.22e54 < a < 7.79999999999999984e72

    1. Initial program 99.6%

      \[\left(\left(\log \left(x + y\right) + \log z\right) - t\right) + \left(a - 0.5\right) \cdot \log t \]
    2. Step-by-step derivation
      1. associate--l+99.6%

        \[\leadsto \color{blue}{\left(\log \left(x + y\right) + \left(\log z - t\right)\right)} + \left(a - 0.5\right) \cdot \log t \]
      2. associate-+l+99.6%

        \[\leadsto \color{blue}{\log \left(x + y\right) + \left(\left(\log z - t\right) + \left(a - 0.5\right) \cdot \log t\right)} \]
      3. +-commutative99.6%

        \[\leadsto \log \left(x + y\right) + \color{blue}{\left(\left(a - 0.5\right) \cdot \log t + \left(\log z - t\right)\right)} \]
      4. fma-def99.6%

        \[\leadsto \log \left(x + y\right) + \color{blue}{\mathsf{fma}\left(a - 0.5, \log t, \log z - t\right)} \]
      5. remove-double-neg99.6%

        \[\leadsto \log \left(x + y\right) + \mathsf{fma}\left(\color{blue}{-\left(-\left(a - 0.5\right)\right)}, \log t, \log z - t\right) \]
      6. remove-double-neg99.6%

        \[\leadsto \log \left(x + y\right) + \mathsf{fma}\left(\color{blue}{a - 0.5}, \log t, \log z - t\right) \]
      7. sub-neg99.6%

        \[\leadsto \log \left(x + y\right) + \mathsf{fma}\left(\color{blue}{a + \left(-0.5\right)}, \log t, \log z - t\right) \]
      8. metadata-eval99.6%

        \[\leadsto \log \left(x + y\right) + \mathsf{fma}\left(a + \color{blue}{-0.5}, \log t, \log z - t\right) \]
    3. Simplified99.6%

      \[\leadsto \color{blue}{\log \left(x + y\right) + \mathsf{fma}\left(a + -0.5, \log t, \log z - t\right)} \]
    4. Taylor expanded in t around inf 55.9%

      \[\leadsto \log \left(x + y\right) + \color{blue}{-1 \cdot t} \]
    5. Step-by-step derivation
      1. neg-mul-155.9%

        \[\leadsto \log \left(x + y\right) + \color{blue}{\left(-t\right)} \]
    6. Simplified55.9%

      \[\leadsto \log \left(x + y\right) + \color{blue}{\left(-t\right)} \]
    7. Taylor expanded in x around 0 43.8%

      \[\leadsto \color{blue}{\log y - t} \]
  3. Recombined 2 regimes into one program.
  4. Final simplification58.8%

    \[\leadsto \begin{array}{l} \mathbf{if}\;a \leq -1.22 \cdot 10^{+54} \lor \neg \left(a \leq 7.8 \cdot 10^{+72}\right):\\ \;\;\;\;a \cdot \log t\\ \mathbf{else}:\\ \;\;\;\;\log y - t\\ \end{array} \]

Alternative 15: 40.6% accurate, 3.0× speedup?

\[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;t \leq 60000000:\\ \;\;\;\;\log \left(x + y\right)\\ \mathbf{else}:\\ \;\;\;\;-t\\ \end{array} \end{array} \]
(FPCore (x y z t a)
 :precision binary64
 (if (<= t 60000000.0) (log (+ x y)) (- t)))
double code(double x, double y, double z, double t, double a) {
	double tmp;
	if (t <= 60000000.0) {
		tmp = log((x + y));
	} else {
		tmp = -t;
	}
	return tmp;
}
real(8) function code(x, y, z, t, a)
    real(8), intent (in) :: x
    real(8), intent (in) :: y
    real(8), intent (in) :: z
    real(8), intent (in) :: t
    real(8), intent (in) :: a
    real(8) :: tmp
    if (t <= 60000000.0d0) then
        tmp = log((x + y))
    else
        tmp = -t
    end if
    code = tmp
end function
public static double code(double x, double y, double z, double t, double a) {
	double tmp;
	if (t <= 60000000.0) {
		tmp = Math.log((x + y));
	} else {
		tmp = -t;
	}
	return tmp;
}
def code(x, y, z, t, a):
	tmp = 0
	if t <= 60000000.0:
		tmp = math.log((x + y))
	else:
		tmp = -t
	return tmp
function code(x, y, z, t, a)
	tmp = 0.0
	if (t <= 60000000.0)
		tmp = log(Float64(x + y));
	else
		tmp = Float64(-t);
	end
	return tmp
end
function tmp_2 = code(x, y, z, t, a)
	tmp = 0.0;
	if (t <= 60000000.0)
		tmp = log((x + y));
	else
		tmp = -t;
	end
	tmp_2 = tmp;
end
code[x_, y_, z_, t_, a_] := If[LessEqual[t, 60000000.0], N[Log[N[(x + y), $MachinePrecision]], $MachinePrecision], (-t)]
\begin{array}{l}

\\
\begin{array}{l}
\mathbf{if}\;t \leq 60000000:\\
\;\;\;\;\log \left(x + y\right)\\

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


\end{array}
\end{array}
Derivation
  1. Split input into 2 regimes
  2. if t < 6e7

    1. Initial program 99.3%

      \[\left(\left(\log \left(x + y\right) + \log z\right) - t\right) + \left(a - 0.5\right) \cdot \log t \]
    2. Step-by-step derivation
      1. associate--l+99.3%

        \[\leadsto \color{blue}{\left(\log \left(x + y\right) + \left(\log z - t\right)\right)} + \left(a - 0.5\right) \cdot \log t \]
      2. associate-+l+99.3%

        \[\leadsto \color{blue}{\log \left(x + y\right) + \left(\left(\log z - t\right) + \left(a - 0.5\right) \cdot \log t\right)} \]
      3. +-commutative99.3%

        \[\leadsto \log \left(x + y\right) + \color{blue}{\left(\left(a - 0.5\right) \cdot \log t + \left(\log z - t\right)\right)} \]
      4. fma-def99.3%

        \[\leadsto \log \left(x + y\right) + \color{blue}{\mathsf{fma}\left(a - 0.5, \log t, \log z - t\right)} \]
      5. remove-double-neg99.3%

        \[\leadsto \log \left(x + y\right) + \mathsf{fma}\left(\color{blue}{-\left(-\left(a - 0.5\right)\right)}, \log t, \log z - t\right) \]
      6. remove-double-neg99.3%

        \[\leadsto \log \left(x + y\right) + \mathsf{fma}\left(\color{blue}{a - 0.5}, \log t, \log z - t\right) \]
      7. sub-neg99.3%

        \[\leadsto \log \left(x + y\right) + \mathsf{fma}\left(\color{blue}{a + \left(-0.5\right)}, \log t, \log z - t\right) \]
      8. metadata-eval99.3%

        \[\leadsto \log \left(x + y\right) + \mathsf{fma}\left(a + \color{blue}{-0.5}, \log t, \log z - t\right) \]
    3. Simplified99.3%

      \[\leadsto \color{blue}{\log \left(x + y\right) + \mathsf{fma}\left(a + -0.5, \log t, \log z - t\right)} \]
    4. Taylor expanded in t around inf 10.3%

      \[\leadsto \log \left(x + y\right) + \color{blue}{-1 \cdot t} \]
    5. Step-by-step derivation
      1. neg-mul-110.3%

        \[\leadsto \log \left(x + y\right) + \color{blue}{\left(-t\right)} \]
    6. Simplified10.3%

      \[\leadsto \log \left(x + y\right) + \color{blue}{\left(-t\right)} \]
    7. Taylor expanded in t around 0 10.3%

      \[\leadsto \color{blue}{\log \left(y + x\right)} \]

    if 6e7 < t

    1. Initial program 99.8%

      \[\left(\left(\log \left(x + y\right) + \log z\right) - t\right) + \left(a - 0.5\right) \cdot \log t \]
    2. Step-by-step derivation
      1. associate--l+99.8%

        \[\leadsto \color{blue}{\left(\log \left(x + y\right) + \left(\log z - t\right)\right)} + \left(a - 0.5\right) \cdot \log t \]
      2. +-commutative99.8%

        \[\leadsto \color{blue}{\left(\left(\log z - t\right) + \log \left(x + y\right)\right)} + \left(a - 0.5\right) \cdot \log t \]
      3. associate-+l+99.8%

        \[\leadsto \color{blue}{\left(\log z - t\right) + \left(\log \left(x + y\right) + \left(a - 0.5\right) \cdot \log t\right)} \]
      4. +-commutative99.8%

        \[\leadsto \left(\log z - t\right) + \color{blue}{\left(\left(a - 0.5\right) \cdot \log t + \log \left(x + y\right)\right)} \]
      5. fma-def99.8%

        \[\leadsto \left(\log z - t\right) + \color{blue}{\mathsf{fma}\left(a - 0.5, \log t, \log \left(x + y\right)\right)} \]
      6. sub-neg99.8%

        \[\leadsto \left(\log z - t\right) + \mathsf{fma}\left(\color{blue}{a + \left(-0.5\right)}, \log t, \log \left(x + y\right)\right) \]
      7. metadata-eval99.8%

        \[\leadsto \left(\log z - t\right) + \mathsf{fma}\left(a + \color{blue}{-0.5}, \log t, \log \left(x + y\right)\right) \]
    3. Simplified99.8%

      \[\leadsto \color{blue}{\left(\log z - t\right) + \mathsf{fma}\left(a + -0.5, \log t, \log \left(x + y\right)\right)} \]
    4. Taylor expanded in t around inf 99.8%

      \[\leadsto \left(\log z - t\right) + \color{blue}{\left(-1 \cdot \left(\log \left(\frac{1}{t}\right) \cdot \left(a - 0.5\right)\right) + \log \left(y + x\right)\right)} \]
    5. Taylor expanded in t around inf 72.8%

      \[\leadsto \color{blue}{-1 \cdot t} \]
    6. Step-by-step derivation
      1. neg-mul-172.8%

        \[\leadsto \color{blue}{-t} \]
    7. Simplified72.8%

      \[\leadsto \color{blue}{-t} \]
  3. Recombined 2 regimes into one program.
  4. Final simplification41.6%

    \[\leadsto \begin{array}{l} \mathbf{if}\;t \leq 60000000:\\ \;\;\;\;\log \left(x + y\right)\\ \mathbf{else}:\\ \;\;\;\;-t\\ \end{array} \]

Alternative 16: 62.0% accurate, 3.0× speedup?

\[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;t \leq 1.6 \cdot 10^{+42}:\\ \;\;\;\;a \cdot \log t\\ \mathbf{else}:\\ \;\;\;\;-t\\ \end{array} \end{array} \]
(FPCore (x y z t a)
 :precision binary64
 (if (<= t 1.6e+42) (* a (log t)) (- t)))
double code(double x, double y, double z, double t, double a) {
	double tmp;
	if (t <= 1.6e+42) {
		tmp = a * log(t);
	} else {
		tmp = -t;
	}
	return tmp;
}
real(8) function code(x, y, z, t, a)
    real(8), intent (in) :: x
    real(8), intent (in) :: y
    real(8), intent (in) :: z
    real(8), intent (in) :: t
    real(8), intent (in) :: a
    real(8) :: tmp
    if (t <= 1.6d+42) then
        tmp = a * log(t)
    else
        tmp = -t
    end if
    code = tmp
end function
public static double code(double x, double y, double z, double t, double a) {
	double tmp;
	if (t <= 1.6e+42) {
		tmp = a * Math.log(t);
	} else {
		tmp = -t;
	}
	return tmp;
}
def code(x, y, z, t, a):
	tmp = 0
	if t <= 1.6e+42:
		tmp = a * math.log(t)
	else:
		tmp = -t
	return tmp
function code(x, y, z, t, a)
	tmp = 0.0
	if (t <= 1.6e+42)
		tmp = Float64(a * log(t));
	else
		tmp = Float64(-t);
	end
	return tmp
end
function tmp_2 = code(x, y, z, t, a)
	tmp = 0.0;
	if (t <= 1.6e+42)
		tmp = a * log(t);
	else
		tmp = -t;
	end
	tmp_2 = tmp;
end
code[x_, y_, z_, t_, a_] := If[LessEqual[t, 1.6e+42], N[(a * N[Log[t], $MachinePrecision]), $MachinePrecision], (-t)]
\begin{array}{l}

\\
\begin{array}{l}
\mathbf{if}\;t \leq 1.6 \cdot 10^{+42}:\\
\;\;\;\;a \cdot \log t\\

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


\end{array}
\end{array}
Derivation
  1. Split input into 2 regimes
  2. if t < 1.60000000000000001e42

    1. Initial program 99.3%

      \[\left(\left(\log \left(x + y\right) + \log z\right) - t\right) + \left(a - 0.5\right) \cdot \log t \]
    2. Step-by-step derivation
      1. associate--l+99.3%

        \[\leadsto \color{blue}{\left(\log \left(x + y\right) + \left(\log z - t\right)\right)} + \left(a - 0.5\right) \cdot \log t \]
      2. +-commutative99.3%

        \[\leadsto \color{blue}{\left(\left(\log z - t\right) + \log \left(x + y\right)\right)} + \left(a - 0.5\right) \cdot \log t \]
      3. associate-+l+99.3%

        \[\leadsto \color{blue}{\left(\log z - t\right) + \left(\log \left(x + y\right) + \left(a - 0.5\right) \cdot \log t\right)} \]
      4. +-commutative99.3%

        \[\leadsto \left(\log z - t\right) + \color{blue}{\left(\left(a - 0.5\right) \cdot \log t + \log \left(x + y\right)\right)} \]
      5. fma-def99.3%

        \[\leadsto \left(\log z - t\right) + \color{blue}{\mathsf{fma}\left(a - 0.5, \log t, \log \left(x + y\right)\right)} \]
      6. sub-neg99.3%

        \[\leadsto \left(\log z - t\right) + \mathsf{fma}\left(\color{blue}{a + \left(-0.5\right)}, \log t, \log \left(x + y\right)\right) \]
      7. metadata-eval99.3%

        \[\leadsto \left(\log z - t\right) + \mathsf{fma}\left(a + \color{blue}{-0.5}, \log t, \log \left(x + y\right)\right) \]
    3. Simplified99.3%

      \[\leadsto \color{blue}{\left(\log z - t\right) + \mathsf{fma}\left(a + -0.5, \log t, \log \left(x + y\right)\right)} \]
    4. Taylor expanded in t around inf 99.3%

      \[\leadsto \left(\log z - t\right) + \color{blue}{\left(-1 \cdot \left(\log \left(\frac{1}{t}\right) \cdot \left(a - 0.5\right)\right) + \log \left(y + x\right)\right)} \]
    5. Taylor expanded in a around inf 48.3%

      \[\leadsto \color{blue}{-1 \cdot \left(a \cdot \log \left(\frac{1}{t}\right)\right)} \]
    6. Step-by-step derivation
      1. mul-1-neg48.3%

        \[\leadsto \color{blue}{-a \cdot \log \left(\frac{1}{t}\right)} \]
      2. log-rec48.3%

        \[\leadsto -a \cdot \color{blue}{\left(-\log t\right)} \]
      3. distribute-rgt-neg-in48.3%

        \[\leadsto \color{blue}{a \cdot \left(-\left(-\log t\right)\right)} \]
      4. remove-double-neg48.3%

        \[\leadsto a \cdot \color{blue}{\log t} \]
    7. Simplified48.3%

      \[\leadsto \color{blue}{a \cdot \log t} \]

    if 1.60000000000000001e42 < t

    1. Initial program 99.9%

      \[\left(\left(\log \left(x + y\right) + \log z\right) - t\right) + \left(a - 0.5\right) \cdot \log t \]
    2. Step-by-step derivation
      1. associate--l+99.9%

        \[\leadsto \color{blue}{\left(\log \left(x + y\right) + \left(\log z - t\right)\right)} + \left(a - 0.5\right) \cdot \log t \]
      2. +-commutative99.9%

        \[\leadsto \color{blue}{\left(\left(\log z - t\right) + \log \left(x + y\right)\right)} + \left(a - 0.5\right) \cdot \log t \]
      3. associate-+l+99.9%

        \[\leadsto \color{blue}{\left(\log z - t\right) + \left(\log \left(x + y\right) + \left(a - 0.5\right) \cdot \log t\right)} \]
      4. +-commutative99.9%

        \[\leadsto \left(\log z - t\right) + \color{blue}{\left(\left(a - 0.5\right) \cdot \log t + \log \left(x + y\right)\right)} \]
      5. fma-def99.9%

        \[\leadsto \left(\log z - t\right) + \color{blue}{\mathsf{fma}\left(a - 0.5, \log t, \log \left(x + y\right)\right)} \]
      6. sub-neg99.9%

        \[\leadsto \left(\log z - t\right) + \mathsf{fma}\left(\color{blue}{a + \left(-0.5\right)}, \log t, \log \left(x + y\right)\right) \]
      7. metadata-eval99.9%

        \[\leadsto \left(\log z - t\right) + \mathsf{fma}\left(a + \color{blue}{-0.5}, \log t, \log \left(x + y\right)\right) \]
    3. Simplified99.9%

      \[\leadsto \color{blue}{\left(\log z - t\right) + \mathsf{fma}\left(a + -0.5, \log t, \log \left(x + y\right)\right)} \]
    4. Taylor expanded in t around inf 99.9%

      \[\leadsto \left(\log z - t\right) + \color{blue}{\left(-1 \cdot \left(\log \left(\frac{1}{t}\right) \cdot \left(a - 0.5\right)\right) + \log \left(y + x\right)\right)} \]
    5. Taylor expanded in t around inf 78.4%

      \[\leadsto \color{blue}{-1 \cdot t} \]
    6. Step-by-step derivation
      1. neg-mul-178.4%

        \[\leadsto \color{blue}{-t} \]
    7. Simplified78.4%

      \[\leadsto \color{blue}{-t} \]
  3. Recombined 2 regimes into one program.
  4. Final simplification61.2%

    \[\leadsto \begin{array}{l} \mathbf{if}\;t \leq 1.6 \cdot 10^{+42}:\\ \;\;\;\;a \cdot \log t\\ \mathbf{else}:\\ \;\;\;\;-t\\ \end{array} \]

Alternative 17: 37.4% accurate, 156.5× speedup?

\[\begin{array}{l} \\ -t \end{array} \]
(FPCore (x y z t a) :precision binary64 (- t))
double code(double x, double y, double z, double t, double a) {
	return -t;
}
real(8) function code(x, y, z, t, a)
    real(8), intent (in) :: x
    real(8), intent (in) :: y
    real(8), intent (in) :: z
    real(8), intent (in) :: t
    real(8), intent (in) :: a
    code = -t
end function
public static double code(double x, double y, double z, double t, double a) {
	return -t;
}
def code(x, y, z, t, a):
	return -t
function code(x, y, z, t, a)
	return Float64(-t)
end
function tmp = code(x, y, z, t, a)
	tmp = -t;
end
code[x_, y_, z_, t_, a_] := (-t)
\begin{array}{l}

\\
-t
\end{array}
Derivation
  1. Initial program 99.6%

    \[\left(\left(\log \left(x + y\right) + \log z\right) - t\right) + \left(a - 0.5\right) \cdot \log t \]
  2. Step-by-step derivation
    1. associate--l+99.6%

      \[\leadsto \color{blue}{\left(\log \left(x + y\right) + \left(\log z - t\right)\right)} + \left(a - 0.5\right) \cdot \log t \]
    2. +-commutative99.6%

      \[\leadsto \color{blue}{\left(\left(\log z - t\right) + \log \left(x + y\right)\right)} + \left(a - 0.5\right) \cdot \log t \]
    3. associate-+l+99.5%

      \[\leadsto \color{blue}{\left(\log z - t\right) + \left(\log \left(x + y\right) + \left(a - 0.5\right) \cdot \log t\right)} \]
    4. +-commutative99.5%

      \[\leadsto \left(\log z - t\right) + \color{blue}{\left(\left(a - 0.5\right) \cdot \log t + \log \left(x + y\right)\right)} \]
    5. fma-def99.5%

      \[\leadsto \left(\log z - t\right) + \color{blue}{\mathsf{fma}\left(a - 0.5, \log t, \log \left(x + y\right)\right)} \]
    6. sub-neg99.5%

      \[\leadsto \left(\log z - t\right) + \mathsf{fma}\left(\color{blue}{a + \left(-0.5\right)}, \log t, \log \left(x + y\right)\right) \]
    7. metadata-eval99.5%

      \[\leadsto \left(\log z - t\right) + \mathsf{fma}\left(a + \color{blue}{-0.5}, \log t, \log \left(x + y\right)\right) \]
  3. Simplified99.5%

    \[\leadsto \color{blue}{\left(\log z - t\right) + \mathsf{fma}\left(a + -0.5, \log t, \log \left(x + y\right)\right)} \]
  4. Taylor expanded in t around inf 99.5%

    \[\leadsto \left(\log z - t\right) + \color{blue}{\left(-1 \cdot \left(\log \left(\frac{1}{t}\right) \cdot \left(a - 0.5\right)\right) + \log \left(y + x\right)\right)} \]
  5. Taylor expanded in t around inf 37.8%

    \[\leadsto \color{blue}{-1 \cdot t} \]
  6. Step-by-step derivation
    1. neg-mul-137.8%

      \[\leadsto \color{blue}{-t} \]
  7. Simplified37.8%

    \[\leadsto \color{blue}{-t} \]
  8. Final simplification37.8%

    \[\leadsto -t \]

Developer target: 99.6% accurate, 1.0× speedup?

\[\begin{array}{l} \\ \log \left(x + y\right) + \left(\left(\log z - t\right) + \left(a - 0.5\right) \cdot \log t\right) \end{array} \]
(FPCore (x y z t a)
 :precision binary64
 (+ (log (+ x y)) (+ (- (log z) t) (* (- a 0.5) (log t)))))
double code(double x, double y, double z, double t, double a) {
	return log((x + y)) + ((log(z) - t) + ((a - 0.5) * log(t)));
}
real(8) function code(x, y, z, t, a)
    real(8), intent (in) :: x
    real(8), intent (in) :: y
    real(8), intent (in) :: z
    real(8), intent (in) :: t
    real(8), intent (in) :: a
    code = log((x + y)) + ((log(z) - t) + ((a - 0.5d0) * log(t)))
end function
public static double code(double x, double y, double z, double t, double a) {
	return Math.log((x + y)) + ((Math.log(z) - t) + ((a - 0.5) * Math.log(t)));
}
def code(x, y, z, t, a):
	return math.log((x + y)) + ((math.log(z) - t) + ((a - 0.5) * math.log(t)))
function code(x, y, z, t, a)
	return Float64(log(Float64(x + y)) + Float64(Float64(log(z) - t) + Float64(Float64(a - 0.5) * log(t))))
end
function tmp = code(x, y, z, t, a)
	tmp = log((x + y)) + ((log(z) - t) + ((a - 0.5) * log(t)));
end
code[x_, y_, z_, t_, a_] := N[(N[Log[N[(x + y), $MachinePrecision]], $MachinePrecision] + N[(N[(N[Log[z], $MachinePrecision] - t), $MachinePrecision] + N[(N[(a - 0.5), $MachinePrecision] * N[Log[t], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}

\\
\log \left(x + y\right) + \left(\left(\log z - t\right) + \left(a - 0.5\right) \cdot \log t\right)
\end{array}

Reproduce

?
herbie shell --seed 2023171 
(FPCore (x y z t a)
  :name "Numeric.SpecFunctions:logGammaL from math-functions-0.1.5.2"
  :precision binary64

  :herbie-target
  (+ (log (+ x y)) (+ (- (log z) t) (* (- a 0.5) (log t))))

  (+ (- (+ (log (+ x y)) (log z)) t) (* (- a 0.5) (log t))))