Numeric.SpecFunctions:logGammaL from math-functions-0.1.5.2

Percentage Accurate: 99.6% → 99.6%
Time: 17.2s
Alternatives: 12
Speedup: 1.0×

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 12 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, 1.0× speedup?

\[\begin{array}{l} \\ \left(\left(\log \left(x + y\right) + \log z\right) - t\right) + \log \left(\frac{1}{t}\right) \cdot \left(0.5 - a\right) \end{array} \]
(FPCore (x y z t a)
 :precision binary64
 (+ (- (+ (log (+ x y)) (log z)) t) (* (log (/ 1.0 t)) (- 0.5 a))))
double code(double x, double y, double z, double t, double a) {
	return ((log((x + y)) + log(z)) - t) + (log((1.0 / t)) * (0.5 - a));
}
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) + (log((1.0d0 / t)) * (0.5d0 - a))
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) + (Math.log((1.0 / t)) * (0.5 - a));
}
def code(x, y, z, t, a):
	return ((math.log((x + y)) + math.log(z)) - t) + (math.log((1.0 / t)) * (0.5 - a))
function code(x, y, z, t, a)
	return Float64(Float64(Float64(log(Float64(x + y)) + log(z)) - t) + Float64(log(Float64(1.0 / t)) * Float64(0.5 - a)))
end
function tmp = code(x, y, z, t, a)
	tmp = ((log((x + y)) + log(z)) - t) + (log((1.0 / t)) * (0.5 - a));
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[Log[N[(1.0 / t), $MachinePrecision]], $MachinePrecision] * N[(0.5 - a), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}

\\
\left(\left(\log \left(x + y\right) + \log z\right) - t\right) + \log \left(\frac{1}{t}\right) \cdot \left(0.5 - a\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. Taylor expanded in t around inf 99.6%

    \[\leadsto \left(\left(\log \left(x + y\right) + \log z\right) - t\right) + \color{blue}{-1 \cdot \left(\log \left(\frac{1}{t}\right) \cdot \left(a - 0.5\right)\right)} \]
  3. Final simplification99.6%

    \[\leadsto \left(\left(\log \left(x + y\right) + \log z\right) - t\right) + \log \left(\frac{1}{t}\right) \cdot \left(0.5 - a\right) \]

Alternative 2: 98.5% accurate, 1.0× speedup?

\[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;t \leq 22.5:\\ \;\;\;\;\log z + \left(\log \left(x + y\right) + \left(a - 0.5\right) \cdot \log t\right)\\ \mathbf{else}:\\ \;\;\;\;\left(\log z - t\right) + a \cdot \log t\\ \end{array} \end{array} \]
(FPCore (x y z t a)
 :precision binary64
 (if (<= t 22.5)
   (+ (log z) (+ (log (+ x y)) (* (- a 0.5) (log t))))
   (+ (- (log z) t) (* a (log t)))))
double code(double x, double y, double z, double t, double a) {
	double tmp;
	if (t <= 22.5) {
		tmp = log(z) + (log((x + y)) + ((a - 0.5) * log(t)));
	} else {
		tmp = (log(z) - t) + (a * log(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 <= 22.5d0) then
        tmp = log(z) + (log((x + y)) + ((a - 0.5d0) * log(t)))
    else
        tmp = (log(z) - t) + (a * log(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 <= 22.5) {
		tmp = Math.log(z) + (Math.log((x + y)) + ((a - 0.5) * Math.log(t)));
	} else {
		tmp = (Math.log(z) - t) + (a * Math.log(t));
	}
	return tmp;
}
def code(x, y, z, t, a):
	tmp = 0
	if t <= 22.5:
		tmp = math.log(z) + (math.log((x + y)) + ((a - 0.5) * math.log(t)))
	else:
		tmp = (math.log(z) - t) + (a * math.log(t))
	return tmp
function code(x, y, z, t, a)
	tmp = 0.0
	if (t <= 22.5)
		tmp = Float64(log(z) + Float64(log(Float64(x + y)) + Float64(Float64(a - 0.5) * log(t))));
	else
		tmp = Float64(Float64(log(z) - t) + Float64(a * log(t)));
	end
	return tmp
end
function tmp_2 = code(x, y, z, t, a)
	tmp = 0.0;
	if (t <= 22.5)
		tmp = log(z) + (log((x + y)) + ((a - 0.5) * log(t)));
	else
		tmp = (log(z) - t) + (a * log(t));
	end
	tmp_2 = tmp;
end
code[x_, y_, z_, t_, a_] := If[LessEqual[t, 22.5], N[(N[Log[z], $MachinePrecision] + N[(N[Log[N[(x + y), $MachinePrecision]], $MachinePrecision] + N[(N[(a - 0.5), $MachinePrecision] * N[Log[t], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision], N[(N[(N[Log[z], $MachinePrecision] - t), $MachinePrecision] + N[(a * N[Log[t], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]]
\begin{array}{l}

\\
\begin{array}{l}
\mathbf{if}\;t \leq 22.5:\\
\;\;\;\;\log z + \left(\log \left(x + y\right) + \left(a - 0.5\right) \cdot \log t\right)\\

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


\end{array}
\end{array}
Derivation
  1. Split input into 2 regimes
  2. if t < 22.5

    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 0 98.1%

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

    if 22.5 < 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 a around inf 99.0%

      \[\leadsto \left(\log z - t\right) + \color{blue}{a \cdot \log t} \]
    5. Step-by-step derivation
      1. *-commutative99.0%

        \[\leadsto \left(\log z - t\right) + \color{blue}{\log t \cdot a} \]
    6. Simplified99.0%

      \[\leadsto \left(\log z - t\right) + \color{blue}{\log t \cdot a} \]
  3. Recombined 2 regimes into one program.
  4. Final simplification98.5%

    \[\leadsto \begin{array}{l} \mathbf{if}\;t \leq 22.5:\\ \;\;\;\;\log z + \left(\log \left(x + y\right) + \left(a - 0.5\right) \cdot \log t\right)\\ \mathbf{else}:\\ \;\;\;\;\left(\log z - t\right) + a \cdot \log t\\ \end{array} \]

Alternative 3: 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}
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. Final simplification99.6%

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

Alternative 4: 80.8% accurate, 1.0× speedup?

\[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;t \leq 22.5:\\ \;\;\;\;\log y + \left(\log z + \left(a - 0.5\right) \cdot \log t\right)\\ \mathbf{else}:\\ \;\;\;\;\left(\log z - t\right) + a \cdot \log t\\ \end{array} \end{array} \]
(FPCore (x y z t a)
 :precision binary64
 (if (<= t 22.5)
   (+ (log y) (+ (log z) (* (- a 0.5) (log t))))
   (+ (- (log z) t) (* a (log t)))))
double code(double x, double y, double z, double t, double a) {
	double tmp;
	if (t <= 22.5) {
		tmp = log(y) + (log(z) + ((a - 0.5) * log(t)));
	} else {
		tmp = (log(z) - t) + (a * log(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 <= 22.5d0) then
        tmp = log(y) + (log(z) + ((a - 0.5d0) * log(t)))
    else
        tmp = (log(z) - t) + (a * log(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 <= 22.5) {
		tmp = Math.log(y) + (Math.log(z) + ((a - 0.5) * Math.log(t)));
	} else {
		tmp = (Math.log(z) - t) + (a * Math.log(t));
	}
	return tmp;
}
def code(x, y, z, t, a):
	tmp = 0
	if t <= 22.5:
		tmp = math.log(y) + (math.log(z) + ((a - 0.5) * math.log(t)))
	else:
		tmp = (math.log(z) - t) + (a * math.log(t))
	return tmp
function code(x, y, z, t, a)
	tmp = 0.0
	if (t <= 22.5)
		tmp = Float64(log(y) + Float64(log(z) + Float64(Float64(a - 0.5) * log(t))));
	else
		tmp = Float64(Float64(log(z) - t) + Float64(a * log(t)));
	end
	return tmp
end
function tmp_2 = code(x, y, z, t, a)
	tmp = 0.0;
	if (t <= 22.5)
		tmp = log(y) + (log(z) + ((a - 0.5) * log(t)));
	else
		tmp = (log(z) - t) + (a * log(t));
	end
	tmp_2 = tmp;
end
code[x_, y_, z_, t_, a_] := If[LessEqual[t, 22.5], N[(N[Log[y], $MachinePrecision] + N[(N[Log[z], $MachinePrecision] + N[(N[(a - 0.5), $MachinePrecision] * N[Log[t], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision], N[(N[(N[Log[z], $MachinePrecision] - t), $MachinePrecision] + N[(a * N[Log[t], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]]
\begin{array}{l}

\\
\begin{array}{l}
\mathbf{if}\;t \leq 22.5:\\
\;\;\;\;\log y + \left(\log z + \left(a - 0.5\right) \cdot \log t\right)\\

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


\end{array}
\end{array}
Derivation
  1. Split input into 2 regimes
  2. if t < 22.5

    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. Taylor expanded in x around 0 64.3%

      \[\leadsto \left(\color{blue}{\left(\log y + \log z\right)} - t\right) + \left(a - 0.5\right) \cdot \log t \]
    3. Taylor expanded in t around 0 63.9%

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

    if 22.5 < 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 a around inf 99.0%

      \[\leadsto \left(\log z - t\right) + \color{blue}{a \cdot \log t} \]
    5. Step-by-step derivation
      1. *-commutative99.0%

        \[\leadsto \left(\log z - t\right) + \color{blue}{\log t \cdot a} \]
    6. Simplified99.0%

      \[\leadsto \left(\log z - t\right) + \color{blue}{\log t \cdot a} \]
  3. Recombined 2 regimes into one program.
  4. Final simplification79.4%

    \[\leadsto \begin{array}{l} \mathbf{if}\;t \leq 22.5:\\ \;\;\;\;\log y + \left(\log z + \left(a - 0.5\right) \cdot \log t\right)\\ \mathbf{else}:\\ \;\;\;\;\left(\log z - t\right) + a \cdot \log t\\ \end{array} \]

Alternative 5: 69.0% accurate, 1.0× speedup?

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

\\
\left(a - 0.5\right) \cdot \log t + \left(\left(\log z + \log y\right) - 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. Taylor expanded in x around 0 67.2%

    \[\leadsto \left(\color{blue}{\left(\log y + \log z\right)} - t\right) + \left(a - 0.5\right) \cdot \log t \]
  3. Final simplification67.2%

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

Alternative 6: 72.9% accurate, 1.5× speedup?

\[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;a \leq -1.1 \cdot 10^{-15} \lor \neg \left(a \leq -1.65 \cdot 10^{-128} \lor \neg \left(a \leq 2.35 \cdot 10^{-112}\right) \land a \leq 1.8 \cdot 10^{-78}\right):\\ \;\;\;\;\left(\log z - t\right) + a \cdot \log t\\ \mathbf{else}:\\ \;\;\;\;\log \left(y \cdot z\right) + \log t \cdot -0.5\\ \end{array} \end{array} \]
(FPCore (x y z t a)
 :precision binary64
 (if (or (<= a -1.1e-15)
         (not
          (or (<= a -1.65e-128) (and (not (<= a 2.35e-112)) (<= a 1.8e-78)))))
   (+ (- (log z) t) (* a (log t)))
   (+ (log (* y z)) (* (log t) -0.5))))
double code(double x, double y, double z, double t, double a) {
	double tmp;
	if ((a <= -1.1e-15) || !((a <= -1.65e-128) || (!(a <= 2.35e-112) && (a <= 1.8e-78)))) {
		tmp = (log(z) - t) + (a * log(t));
	} else {
		tmp = log((y * z)) + (log(t) * -0.5);
	}
	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 <= (-1.1d-15)) .or. (.not. (a <= (-1.65d-128)) .or. (.not. (a <= 2.35d-112)) .and. (a <= 1.8d-78))) then
        tmp = (log(z) - t) + (a * log(t))
    else
        tmp = log((y * z)) + (log(t) * (-0.5d0))
    end if
    code = tmp
end function
public static double code(double x, double y, double z, double t, double a) {
	double tmp;
	if ((a <= -1.1e-15) || !((a <= -1.65e-128) || (!(a <= 2.35e-112) && (a <= 1.8e-78)))) {
		tmp = (Math.log(z) - t) + (a * Math.log(t));
	} else {
		tmp = Math.log((y * z)) + (Math.log(t) * -0.5);
	}
	return tmp;
}
def code(x, y, z, t, a):
	tmp = 0
	if (a <= -1.1e-15) or not ((a <= -1.65e-128) or (not (a <= 2.35e-112) and (a <= 1.8e-78))):
		tmp = (math.log(z) - t) + (a * math.log(t))
	else:
		tmp = math.log((y * z)) + (math.log(t) * -0.5)
	return tmp
function code(x, y, z, t, a)
	tmp = 0.0
	if ((a <= -1.1e-15) || !((a <= -1.65e-128) || (!(a <= 2.35e-112) && (a <= 1.8e-78))))
		tmp = Float64(Float64(log(z) - t) + Float64(a * log(t)));
	else
		tmp = Float64(log(Float64(y * z)) + Float64(log(t) * -0.5));
	end
	return tmp
end
function tmp_2 = code(x, y, z, t, a)
	tmp = 0.0;
	if ((a <= -1.1e-15) || ~(((a <= -1.65e-128) || (~((a <= 2.35e-112)) && (a <= 1.8e-78)))))
		tmp = (log(z) - t) + (a * log(t));
	else
		tmp = log((y * z)) + (log(t) * -0.5);
	end
	tmp_2 = tmp;
end
code[x_, y_, z_, t_, a_] := If[Or[LessEqual[a, -1.1e-15], N[Not[Or[LessEqual[a, -1.65e-128], And[N[Not[LessEqual[a, 2.35e-112]], $MachinePrecision], LessEqual[a, 1.8e-78]]]], $MachinePrecision]], N[(N[(N[Log[z], $MachinePrecision] - t), $MachinePrecision] + N[(a * N[Log[t], $MachinePrecision]), $MachinePrecision]), $MachinePrecision], N[(N[Log[N[(y * z), $MachinePrecision]], $MachinePrecision] + N[(N[Log[t], $MachinePrecision] * -0.5), $MachinePrecision]), $MachinePrecision]]
\begin{array}{l}

\\
\begin{array}{l}
\mathbf{if}\;a \leq -1.1 \cdot 10^{-15} \lor \neg \left(a \leq -1.65 \cdot 10^{-128} \lor \neg \left(a \leq 2.35 \cdot 10^{-112}\right) \land a \leq 1.8 \cdot 10^{-78}\right):\\
\;\;\;\;\left(\log z - t\right) + a \cdot \log t\\

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


\end{array}
\end{array}
Derivation
  1. Split input into 2 regimes
  2. if a < -1.09999999999999993e-15 or -1.65e-128 < a < 2.3500000000000002e-112 or 1.8000000000000001e-78 < a

    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+99.6%

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

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

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

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

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

      \[\leadsto \color{blue}{\left(\log z - t\right) + \mathsf{fma}\left(a + -0.5, \log t, \log \left(x + y\right)\right)} \]
    4. Taylor expanded in a around inf 81.4%

      \[\leadsto \left(\log z - t\right) + \color{blue}{a \cdot \log t} \]
    5. Step-by-step derivation
      1. *-commutative81.4%

        \[\leadsto \left(\log z - t\right) + \color{blue}{\log t \cdot a} \]
    6. Simplified81.4%

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

    if -1.09999999999999993e-15 < a < -1.65e-128 or 2.3500000000000002e-112 < a < 1.8000000000000001e-78

    1. Initial program 99.1%

      \[\left(\left(\log \left(x + y\right) + \log z\right) - t\right) + \left(a - 0.5\right) \cdot \log t \]
    2. Taylor expanded in x around 0 62.4%

      \[\leadsto \left(\color{blue}{\left(\log y + \log z\right)} - t\right) + \left(a - 0.5\right) \cdot \log t \]
    3. Taylor expanded in a around 0 62.4%

      \[\leadsto \left(\left(\log y + \log z\right) - t\right) + \color{blue}{-0.5 \cdot \log t} \]
    4. Taylor expanded in t around 0 46.9%

      \[\leadsto \color{blue}{\log y + \left(\log z + -0.5 \cdot \log t\right)} \]
    5. Step-by-step derivation
      1. log-pow46.9%

        \[\leadsto \log y + \left(\log z + \color{blue}{\log \left({t}^{-0.5}\right)}\right) \]
      2. associate-+r+46.9%

        \[\leadsto \color{blue}{\left(\log y + \log z\right) + \log \left({t}^{-0.5}\right)} \]
      3. log-prod42.2%

        \[\leadsto \color{blue}{\log \left(y \cdot z\right)} + \log \left({t}^{-0.5}\right) \]
      4. log-pow42.2%

        \[\leadsto \log \left(y \cdot z\right) + \color{blue}{-0.5 \cdot \log t} \]
      5. *-commutative42.2%

        \[\leadsto \log \left(y \cdot z\right) + \color{blue}{\log t \cdot -0.5} \]
    6. Simplified42.2%

      \[\leadsto \color{blue}{\log \left(y \cdot z\right) + \log t \cdot -0.5} \]
  3. Recombined 2 regimes into one program.
  4. Final simplification74.9%

    \[\leadsto \begin{array}{l} \mathbf{if}\;a \leq -1.1 \cdot 10^{-15} \lor \neg \left(a \leq -1.65 \cdot 10^{-128} \lor \neg \left(a \leq 2.35 \cdot 10^{-112}\right) \land a \leq 1.8 \cdot 10^{-78}\right):\\ \;\;\;\;\left(\log z - t\right) + a \cdot \log t\\ \mathbf{else}:\\ \;\;\;\;\log \left(y \cdot z\right) + \log t \cdot -0.5\\ \end{array} \]

Alternative 7: 84.4% accurate, 1.5× speedup?

\[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;a \leq -9.5 \cdot 10^{-11} \lor \neg \left(a \leq 1.7 \cdot 10^{-11}\right):\\ \;\;\;\;\left(\log z - t\right) + a \cdot \log t\\ \mathbf{else}:\\ \;\;\;\;\log \left(\left(x + y\right) \cdot \left(z \cdot {t}^{-0.5}\right)\right) - t\\ \end{array} \end{array} \]
(FPCore (x y z t a)
 :precision binary64
 (if (or (<= a -9.5e-11) (not (<= a 1.7e-11)))
   (+ (- (log z) t) (* a (log t)))
   (- (log (* (+ x y) (* z (pow t -0.5)))) t)))
double code(double x, double y, double z, double t, double a) {
	double tmp;
	if ((a <= -9.5e-11) || !(a <= 1.7e-11)) {
		tmp = (log(z) - t) + (a * log(t));
	} else {
		tmp = log(((x + y) * (z * pow(t, -0.5)))) - 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 <= (-9.5d-11)) .or. (.not. (a <= 1.7d-11))) then
        tmp = (log(z) - t) + (a * log(t))
    else
        tmp = log(((x + y) * (z * (t ** (-0.5d0))))) - 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 <= -9.5e-11) || !(a <= 1.7e-11)) {
		tmp = (Math.log(z) - t) + (a * Math.log(t));
	} else {
		tmp = Math.log(((x + y) * (z * Math.pow(t, -0.5)))) - t;
	}
	return tmp;
}
def code(x, y, z, t, a):
	tmp = 0
	if (a <= -9.5e-11) or not (a <= 1.7e-11):
		tmp = (math.log(z) - t) + (a * math.log(t))
	else:
		tmp = math.log(((x + y) * (z * math.pow(t, -0.5)))) - t
	return tmp
function code(x, y, z, t, a)
	tmp = 0.0
	if ((a <= -9.5e-11) || !(a <= 1.7e-11))
		tmp = Float64(Float64(log(z) - t) + Float64(a * log(t)));
	else
		tmp = Float64(log(Float64(Float64(x + y) * Float64(z * (t ^ -0.5)))) - t);
	end
	return tmp
end
function tmp_2 = code(x, y, z, t, a)
	tmp = 0.0;
	if ((a <= -9.5e-11) || ~((a <= 1.7e-11)))
		tmp = (log(z) - t) + (a * log(t));
	else
		tmp = log(((x + y) * (z * (t ^ -0.5)))) - t;
	end
	tmp_2 = tmp;
end
code[x_, y_, z_, t_, a_] := If[Or[LessEqual[a, -9.5e-11], N[Not[LessEqual[a, 1.7e-11]], $MachinePrecision]], N[(N[(N[Log[z], $MachinePrecision] - t), $MachinePrecision] + N[(a * N[Log[t], $MachinePrecision]), $MachinePrecision]), $MachinePrecision], N[(N[Log[N[(N[(x + y), $MachinePrecision] * N[(z * N[Power[t, -0.5], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]], $MachinePrecision] - t), $MachinePrecision]]
\begin{array}{l}

\\
\begin{array}{l}
\mathbf{if}\;a \leq -9.5 \cdot 10^{-11} \lor \neg \left(a \leq 1.7 \cdot 10^{-11}\right):\\
\;\;\;\;\left(\log z - t\right) + a \cdot \log t\\

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


\end{array}
\end{array}
Derivation
  1. Split input into 2 regimes
  2. if a < -9.49999999999999951e-11 or 1.6999999999999999e-11 < a

    1. Initial program 99.7%

      \[\left(\left(\log \left(x + y\right) + \log z\right) - t\right) + \left(a - 0.5\right) \cdot \log t \]
    2. Step-by-step derivation
      1. associate--l+99.7%

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

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

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

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

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

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

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

      \[\leadsto \color{blue}{\left(\log z - t\right) + \mathsf{fma}\left(a + -0.5, \log t, \log \left(x + y\right)\right)} \]
    4. Taylor expanded in a around inf 97.1%

      \[\leadsto \left(\log z - t\right) + \color{blue}{a \cdot \log t} \]
    5. Step-by-step derivation
      1. *-commutative97.1%

        \[\leadsto \left(\log z - t\right) + \color{blue}{\log t \cdot a} \]
    6. Simplified97.1%

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

    if -9.49999999999999951e-11 < a < 1.6999999999999999e-11

    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. Taylor expanded in t around inf 99.4%

      \[\leadsto \left(\left(\log \left(x + y\right) + \log z\right) - t\right) + \color{blue}{-1 \cdot \left(\log \left(\frac{1}{t}\right) \cdot \left(a - 0.5\right)\right)} \]
    3. Step-by-step derivation
      1. add-exp-log59.1%

        \[\leadsto \left(\left(\log \left(x + y\right) + \log z\right) - t\right) + -1 \cdot \left(\color{blue}{e^{\log \log \left(\frac{1}{t}\right)}} \cdot \left(a - 0.5\right)\right) \]
      2. log-rec59.1%

        \[\leadsto \left(\left(\log \left(x + y\right) + \log z\right) - t\right) + -1 \cdot \left(e^{\log \color{blue}{\left(-\log t\right)}} \cdot \left(a - 0.5\right)\right) \]
    4. Applied egg-rr59.1%

      \[\leadsto \left(\left(\log \left(x + y\right) + \log z\right) - t\right) + -1 \cdot \left(\color{blue}{e^{\log \left(-\log t\right)}} \cdot \left(a - 0.5\right)\right) \]
    5. Taylor expanded in a around 0 99.4%

      \[\leadsto \color{blue}{\left(\log z + \left(\log \left(x + y\right) + -0.5 \cdot \log t\right)\right) - t} \]
    6. Step-by-step derivation
      1. log-pow99.4%

        \[\leadsto \left(\log z + \left(\log \left(x + y\right) + \color{blue}{\log \left({t}^{-0.5}\right)}\right)\right) - t \]
      2. log-prod87.8%

        \[\leadsto \left(\log z + \color{blue}{\log \left(\left(x + y\right) \cdot {t}^{-0.5}\right)}\right) - t \]
      3. log-prod76.5%

        \[\leadsto \color{blue}{\log \left(z \cdot \left(\left(x + y\right) \cdot {t}^{-0.5}\right)\right)} - t \]
      4. *-commutative76.5%

        \[\leadsto \log \color{blue}{\left(\left(\left(x + y\right) \cdot {t}^{-0.5}\right) \cdot z\right)} - t \]
      5. associate-*l*79.6%

        \[\leadsto \log \color{blue}{\left(\left(x + y\right) \cdot \left({t}^{-0.5} \cdot z\right)\right)} - t \]
      6. +-commutative79.6%

        \[\leadsto \log \left(\color{blue}{\left(y + x\right)} \cdot \left({t}^{-0.5} \cdot z\right)\right) - t \]
    7. Simplified79.6%

      \[\leadsto \color{blue}{\log \left(\left(y + x\right) \cdot \left({t}^{-0.5} \cdot z\right)\right) - t} \]
  3. Recombined 2 regimes into one program.
  4. Final simplification88.7%

    \[\leadsto \begin{array}{l} \mathbf{if}\;a \leq -9.5 \cdot 10^{-11} \lor \neg \left(a \leq 1.7 \cdot 10^{-11}\right):\\ \;\;\;\;\left(\log z - t\right) + a \cdot \log t\\ \mathbf{else}:\\ \;\;\;\;\log \left(\left(x + y\right) \cdot \left(z \cdot {t}^{-0.5}\right)\right) - t\\ \end{array} \]

Alternative 8: 58.2% accurate, 1.5× speedup?

\[\begin{array}{l} \\ \begin{array}{l} t_1 := \log \left(y \cdot z\right) + \log t \cdot -0.5\\ \mathbf{if}\;t \leq 6.8 \cdot 10^{-280}:\\ \;\;\;\;t_1\\ \mathbf{elif}\;t \leq 1.5 \cdot 10^{-57}:\\ \;\;\;\;a \cdot \log t\\ \mathbf{elif}\;t \leq 1.3 \cdot 10^{-15}:\\ \;\;\;\;t_1\\ \mathbf{elif}\;t \leq 1.6 \cdot 10^{+51}:\\ \;\;\;\;\log \left(\frac{1}{t}\right) \cdot \left(-a\right)\\ \mathbf{else}:\\ \;\;\;\;-t\\ \end{array} \end{array} \]
(FPCore (x y z t a)
 :precision binary64
 (let* ((t_1 (+ (log (* y z)) (* (log t) -0.5))))
   (if (<= t 6.8e-280)
     t_1
     (if (<= t 1.5e-57)
       (* a (log t))
       (if (<= t 1.3e-15)
         t_1
         (if (<= t 1.6e+51) (* (log (/ 1.0 t)) (- a)) (- t)))))))
double code(double x, double y, double z, double t, double a) {
	double t_1 = log((y * z)) + (log(t) * -0.5);
	double tmp;
	if (t <= 6.8e-280) {
		tmp = t_1;
	} else if (t <= 1.5e-57) {
		tmp = a * log(t);
	} else if (t <= 1.3e-15) {
		tmp = t_1;
	} else if (t <= 1.6e+51) {
		tmp = log((1.0 / t)) * -a;
	} 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) :: t_1
    real(8) :: tmp
    t_1 = log((y * z)) + (log(t) * (-0.5d0))
    if (t <= 6.8d-280) then
        tmp = t_1
    else if (t <= 1.5d-57) then
        tmp = a * log(t)
    else if (t <= 1.3d-15) then
        tmp = t_1
    else if (t <= 1.6d+51) then
        tmp = log((1.0d0 / t)) * -a
    else
        tmp = -t
    end if
    code = tmp
end function
public static double code(double x, double y, double z, double t, double a) {
	double t_1 = Math.log((y * z)) + (Math.log(t) * -0.5);
	double tmp;
	if (t <= 6.8e-280) {
		tmp = t_1;
	} else if (t <= 1.5e-57) {
		tmp = a * Math.log(t);
	} else if (t <= 1.3e-15) {
		tmp = t_1;
	} else if (t <= 1.6e+51) {
		tmp = Math.log((1.0 / t)) * -a;
	} else {
		tmp = -t;
	}
	return tmp;
}
def code(x, y, z, t, a):
	t_1 = math.log((y * z)) + (math.log(t) * -0.5)
	tmp = 0
	if t <= 6.8e-280:
		tmp = t_1
	elif t <= 1.5e-57:
		tmp = a * math.log(t)
	elif t <= 1.3e-15:
		tmp = t_1
	elif t <= 1.6e+51:
		tmp = math.log((1.0 / t)) * -a
	else:
		tmp = -t
	return tmp
function code(x, y, z, t, a)
	t_1 = Float64(log(Float64(y * z)) + Float64(log(t) * -0.5))
	tmp = 0.0
	if (t <= 6.8e-280)
		tmp = t_1;
	elseif (t <= 1.5e-57)
		tmp = Float64(a * log(t));
	elseif (t <= 1.3e-15)
		tmp = t_1;
	elseif (t <= 1.6e+51)
		tmp = Float64(log(Float64(1.0 / t)) * Float64(-a));
	else
		tmp = Float64(-t);
	end
	return tmp
end
function tmp_2 = code(x, y, z, t, a)
	t_1 = log((y * z)) + (log(t) * -0.5);
	tmp = 0.0;
	if (t <= 6.8e-280)
		tmp = t_1;
	elseif (t <= 1.5e-57)
		tmp = a * log(t);
	elseif (t <= 1.3e-15)
		tmp = t_1;
	elseif (t <= 1.6e+51)
		tmp = log((1.0 / t)) * -a;
	else
		tmp = -t;
	end
	tmp_2 = tmp;
end
code[x_, y_, z_, t_, a_] := Block[{t$95$1 = N[(N[Log[N[(y * z), $MachinePrecision]], $MachinePrecision] + N[(N[Log[t], $MachinePrecision] * -0.5), $MachinePrecision]), $MachinePrecision]}, If[LessEqual[t, 6.8e-280], t$95$1, If[LessEqual[t, 1.5e-57], N[(a * N[Log[t], $MachinePrecision]), $MachinePrecision], If[LessEqual[t, 1.3e-15], t$95$1, If[LessEqual[t, 1.6e+51], N[(N[Log[N[(1.0 / t), $MachinePrecision]], $MachinePrecision] * (-a)), $MachinePrecision], (-t)]]]]]
\begin{array}{l}

\\
\begin{array}{l}
t_1 := \log \left(y \cdot z\right) + \log t \cdot -0.5\\
\mathbf{if}\;t \leq 6.8 \cdot 10^{-280}:\\
\;\;\;\;t_1\\

\mathbf{elif}\;t \leq 1.5 \cdot 10^{-57}:\\
\;\;\;\;a \cdot \log t\\

\mathbf{elif}\;t \leq 1.3 \cdot 10^{-15}:\\
\;\;\;\;t_1\\

\mathbf{elif}\;t \leq 1.6 \cdot 10^{+51}:\\
\;\;\;\;\log \left(\frac{1}{t}\right) \cdot \left(-a\right)\\

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


\end{array}
\end{array}
Derivation
  1. Split input into 4 regimes
  2. if t < 6.7999999999999995e-280 or 1.5e-57 < t < 1.30000000000000002e-15

    1. Initial program 98.9%

      \[\left(\left(\log \left(x + y\right) + \log z\right) - t\right) + \left(a - 0.5\right) \cdot \log t \]
    2. Taylor expanded in x around 0 63.5%

      \[\leadsto \left(\color{blue}{\left(\log y + \log z\right)} - t\right) + \left(a - 0.5\right) \cdot \log t \]
    3. Taylor expanded in a around 0 41.7%

      \[\leadsto \left(\left(\log y + \log z\right) - t\right) + \color{blue}{-0.5 \cdot \log t} \]
    4. Taylor expanded in t around 0 41.8%

      \[\leadsto \color{blue}{\log y + \left(\log z + -0.5 \cdot \log t\right)} \]
    5. Step-by-step derivation
      1. log-pow41.8%

        \[\leadsto \log y + \left(\log z + \color{blue}{\log \left({t}^{-0.5}\right)}\right) \]
      2. associate-+r+41.7%

        \[\leadsto \color{blue}{\left(\log y + \log z\right) + \log \left({t}^{-0.5}\right)} \]
      3. log-prod38.4%

        \[\leadsto \color{blue}{\log \left(y \cdot z\right)} + \log \left({t}^{-0.5}\right) \]
      4. log-pow38.4%

        \[\leadsto \log \left(y \cdot z\right) + \color{blue}{-0.5 \cdot \log t} \]
      5. *-commutative38.4%

        \[\leadsto \log \left(y \cdot z\right) + \color{blue}{\log t \cdot -0.5} \]
    6. Simplified38.4%

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

    if 6.7999999999999995e-280 < t < 1.5e-57

    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. Taylor expanded in t around inf 99.4%

      \[\leadsto \left(\left(\log \left(x + y\right) + \log z\right) - t\right) + \color{blue}{-1 \cdot \left(\log \left(\frac{1}{t}\right) \cdot \left(a - 0.5\right)\right)} \]
    3. Taylor expanded in a around inf 53.6%

      \[\leadsto \color{blue}{-1 \cdot \left(a \cdot \log \left(\frac{1}{t}\right)\right)} \]
    4. Step-by-step derivation
      1. mul-1-neg53.6%

        \[\leadsto \color{blue}{-a \cdot \log \left(\frac{1}{t}\right)} \]
      2. log-rec53.6%

        \[\leadsto -a \cdot \color{blue}{\left(-\log t\right)} \]
      3. distribute-rgt-neg-in53.6%

        \[\leadsto \color{blue}{a \cdot \left(-\left(-\log t\right)\right)} \]
      4. remove-double-neg53.6%

        \[\leadsto a \cdot \color{blue}{\log t} \]
    5. Simplified53.6%

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

    if 1.30000000000000002e-15 < t < 1.6000000000000001e51

    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. Taylor expanded in t around inf 99.7%

      \[\leadsto \left(\left(\log \left(x + y\right) + \log z\right) - t\right) + \color{blue}{-1 \cdot \left(\log \left(\frac{1}{t}\right) \cdot \left(a - 0.5\right)\right)} \]
    3. Taylor expanded in a around inf 64.2%

      \[\leadsto \color{blue}{-1 \cdot \left(a \cdot \log \left(\frac{1}{t}\right)\right)} \]

    if 1.6000000000000001e51 < 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 83.5%

      \[\leadsto \color{blue}{-1 \cdot t} \]
    5. Step-by-step derivation
      1. neg-mul-183.5%

        \[\leadsto \color{blue}{-t} \]
    6. Simplified83.5%

      \[\leadsto \color{blue}{-t} \]
  3. Recombined 4 regimes into one program.
  4. Final simplification63.1%

    \[\leadsto \begin{array}{l} \mathbf{if}\;t \leq 6.8 \cdot 10^{-280}:\\ \;\;\;\;\log \left(y \cdot z\right) + \log t \cdot -0.5\\ \mathbf{elif}\;t \leq 1.5 \cdot 10^{-57}:\\ \;\;\;\;a \cdot \log t\\ \mathbf{elif}\;t \leq 1.3 \cdot 10^{-15}:\\ \;\;\;\;\log \left(y \cdot z\right) + \log t \cdot -0.5\\ \mathbf{elif}\;t \leq 1.6 \cdot 10^{+51}:\\ \;\;\;\;\log \left(\frac{1}{t}\right) \cdot \left(-a\right)\\ \mathbf{else}:\\ \;\;\;\;-t\\ \end{array} \]

Alternative 9: 72.2% accurate, 1.5× speedup?

\[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;a \leq -1.5 \cdot 10^{-9} \lor \neg \left(a \leq 1.7 \cdot 10^{-11}\right):\\ \;\;\;\;\left(\log z - t\right) + a \cdot \log t\\ \mathbf{else}:\\ \;\;\;\;\log \left(y \cdot \left(z \cdot {t}^{-0.5}\right)\right) - t\\ \end{array} \end{array} \]
(FPCore (x y z t a)
 :precision binary64
 (if (or (<= a -1.5e-9) (not (<= a 1.7e-11)))
   (+ (- (log z) t) (* a (log 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 <= -1.5e-9) || !(a <= 1.7e-11)) {
		tmp = (log(z) - t) + (a * log(t));
	} else {
		tmp = log((y * (z * pow(t, -0.5)))) - 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 <= (-1.5d-9)) .or. (.not. (a <= 1.7d-11))) then
        tmp = (log(z) - t) + (a * log(t))
    else
        tmp = log((y * (z * (t ** (-0.5d0))))) - 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 <= -1.5e-9) || !(a <= 1.7e-11)) {
		tmp = (Math.log(z) - t) + (a * Math.log(t));
	} else {
		tmp = Math.log((y * (z * Math.pow(t, -0.5)))) - t;
	}
	return tmp;
}
def code(x, y, z, t, a):
	tmp = 0
	if (a <= -1.5e-9) or not (a <= 1.7e-11):
		tmp = (math.log(z) - t) + (a * math.log(t))
	else:
		tmp = math.log((y * (z * math.pow(t, -0.5)))) - t
	return tmp
function code(x, y, z, t, a)
	tmp = 0.0
	if ((a <= -1.5e-9) || !(a <= 1.7e-11))
		tmp = Float64(Float64(log(z) - t) + Float64(a * log(t)));
	else
		tmp = Float64(log(Float64(y * Float64(z * (t ^ -0.5)))) - t);
	end
	return tmp
end
function tmp_2 = code(x, y, z, t, a)
	tmp = 0.0;
	if ((a <= -1.5e-9) || ~((a <= 1.7e-11)))
		tmp = (log(z) - t) + (a * log(t));
	else
		tmp = log((y * (z * (t ^ -0.5)))) - t;
	end
	tmp_2 = tmp;
end
code[x_, y_, z_, t_, a_] := If[Or[LessEqual[a, -1.5e-9], N[Not[LessEqual[a, 1.7e-11]], $MachinePrecision]], N[(N[(N[Log[z], $MachinePrecision] - t), $MachinePrecision] + N[(a * N[Log[t], $MachinePrecision]), $MachinePrecision]), $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 -1.5 \cdot 10^{-9} \lor \neg \left(a \leq 1.7 \cdot 10^{-11}\right):\\
\;\;\;\;\left(\log z - t\right) + a \cdot \log t\\

\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 < -1.49999999999999999e-9 or 1.6999999999999999e-11 < a

    1. Initial program 99.7%

      \[\left(\left(\log \left(x + y\right) + \log z\right) - t\right) + \left(a - 0.5\right) \cdot \log t \]
    2. Step-by-step derivation
      1. associate--l+99.7%

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

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

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

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

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

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

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

      \[\leadsto \color{blue}{\left(\log z - t\right) + \mathsf{fma}\left(a + -0.5, \log t, \log \left(x + y\right)\right)} \]
    4. Taylor expanded in a around inf 97.1%

      \[\leadsto \left(\log z - t\right) + \color{blue}{a \cdot \log t} \]
    5. Step-by-step derivation
      1. *-commutative97.1%

        \[\leadsto \left(\log z - t\right) + \color{blue}{\log t \cdot a} \]
    6. Simplified97.1%

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

    if -1.49999999999999999e-9 < a < 1.6999999999999999e-11

    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. Taylor expanded in x around 0 62.8%

      \[\leadsto \left(\color{blue}{\left(\log y + \log z\right)} - t\right) + \left(a - 0.5\right) \cdot \log t \]
    3. Taylor expanded in a around 0 62.8%

      \[\leadsto \left(\left(\log y + \log z\right) - t\right) + \color{blue}{-0.5 \cdot \log t} \]
    4. Taylor expanded in y around 0 62.8%

      \[\leadsto \color{blue}{\left(\log y + \left(\log z + -0.5 \cdot \log t\right)\right) - t} \]
    5. Step-by-step derivation
      1. log-pow62.8%

        \[\leadsto \left(\log y + \left(\log z + \color{blue}{\log \left({t}^{-0.5}\right)}\right)\right) - t \]
      2. associate-+r+62.8%

        \[\leadsto \color{blue}{\left(\left(\log y + \log z\right) + \log \left({t}^{-0.5}\right)\right)} - t \]
      3. log-prod48.4%

        \[\leadsto \left(\color{blue}{\log \left(y \cdot z\right)} + \log \left({t}^{-0.5}\right)\right) - t \]
      4. associate--l+48.4%

        \[\leadsto \color{blue}{\log \left(y \cdot z\right) + \left(\log \left({t}^{-0.5}\right) - t\right)} \]
      5. unsub-neg48.4%

        \[\leadsto \log \left(y \cdot z\right) + \color{blue}{\left(\log \left({t}^{-0.5}\right) + \left(-t\right)\right)} \]
      6. +-commutative48.4%

        \[\leadsto \log \left(y \cdot z\right) + \color{blue}{\left(\left(-t\right) + \log \left({t}^{-0.5}\right)\right)} \]
      7. neg-sub048.4%

        \[\leadsto \log \left(y \cdot z\right) + \left(\color{blue}{\left(0 - t\right)} + \log \left({t}^{-0.5}\right)\right) \]
      8. associate-+l-48.4%

        \[\leadsto \log \left(y \cdot z\right) + \color{blue}{\left(0 - \left(t - \log \left({t}^{-0.5}\right)\right)\right)} \]
      9. neg-sub048.4%

        \[\leadsto \log \left(y \cdot z\right) + \color{blue}{\left(-\left(t - \log \left({t}^{-0.5}\right)\right)\right)} \]
      10. sub-neg48.4%

        \[\leadsto \color{blue}{\log \left(y \cdot z\right) - \left(t - \log \left({t}^{-0.5}\right)\right)} \]
      11. associate--r-48.4%

        \[\leadsto \color{blue}{\left(\log \left(y \cdot z\right) - t\right) + \log \left({t}^{-0.5}\right)} \]
      12. rem-log-exp28.4%

        \[\leadsto \left(\log \left(y \cdot z\right) - \color{blue}{\log \left(e^{t}\right)}\right) + \log \left({t}^{-0.5}\right) \]
      13. log-div29.0%

        \[\leadsto \color{blue}{\log \left(\frac{y \cdot z}{e^{t}}\right)} + \log \left({t}^{-0.5}\right) \]
      14. log-prod26.6%

        \[\leadsto \color{blue}{\log \left(\frac{y \cdot z}{e^{t}} \cdot {t}^{-0.5}\right)} \]
      15. *-commutative26.6%

        \[\leadsto \log \color{blue}{\left({t}^{-0.5} \cdot \frac{y \cdot z}{e^{t}}\right)} \]
      16. associate-*r/26.6%

        \[\leadsto \log \color{blue}{\left(\frac{{t}^{-0.5} \cdot \left(y \cdot z\right)}{e^{t}}\right)} \]
      17. log-div26.2%

        \[\leadsto \color{blue}{\log \left({t}^{-0.5} \cdot \left(y \cdot z\right)\right) - \log \left(e^{t}\right)} \]
    6. Simplified49.5%

      \[\leadsto \color{blue}{\log \left(\left({t}^{-0.5} \cdot z\right) \cdot y\right) - t} \]
  3. Recombined 2 regimes into one program.
  4. Final simplification74.2%

    \[\leadsto \begin{array}{l} \mathbf{if}\;a \leq -1.5 \cdot 10^{-9} \lor \neg \left(a \leq 1.7 \cdot 10^{-11}\right):\\ \;\;\;\;\left(\log z - t\right) + a \cdot \log t\\ \mathbf{else}:\\ \;\;\;\;\log \left(y \cdot \left(z \cdot {t}^{-0.5}\right)\right) - t\\ \end{array} \]

Alternative 10: 61.5% accurate, 2.9× speedup?

\[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;t \leq 2.35 \cdot 10^{+51}:\\ \;\;\;\;\log \left(\frac{1}{t}\right) \cdot \left(-a\right)\\ \mathbf{else}:\\ \;\;\;\;-t\\ \end{array} \end{array} \]
(FPCore (x y z t a)
 :precision binary64
 (if (<= t 2.35e+51) (* (log (/ 1.0 t)) (- a)) (- t)))
double code(double x, double y, double z, double t, double a) {
	double tmp;
	if (t <= 2.35e+51) {
		tmp = log((1.0 / t)) * -a;
	} 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 <= 2.35d+51) then
        tmp = log((1.0d0 / t)) * -a
    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 <= 2.35e+51) {
		tmp = Math.log((1.0 / t)) * -a;
	} else {
		tmp = -t;
	}
	return tmp;
}
def code(x, y, z, t, a):
	tmp = 0
	if t <= 2.35e+51:
		tmp = math.log((1.0 / t)) * -a
	else:
		tmp = -t
	return tmp
function code(x, y, z, t, a)
	tmp = 0.0
	if (t <= 2.35e+51)
		tmp = Float64(log(Float64(1.0 / t)) * Float64(-a));
	else
		tmp = Float64(-t);
	end
	return tmp
end
function tmp_2 = code(x, y, z, t, a)
	tmp = 0.0;
	if (t <= 2.35e+51)
		tmp = log((1.0 / t)) * -a;
	else
		tmp = -t;
	end
	tmp_2 = tmp;
end
code[x_, y_, z_, t_, a_] := If[LessEqual[t, 2.35e+51], N[(N[Log[N[(1.0 / t), $MachinePrecision]], $MachinePrecision] * (-a)), $MachinePrecision], (-t)]
\begin{array}{l}

\\
\begin{array}{l}
\mathbf{if}\;t \leq 2.35 \cdot 10^{+51}:\\
\;\;\;\;\log \left(\frac{1}{t}\right) \cdot \left(-a\right)\\

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


\end{array}
\end{array}
Derivation
  1. Split input into 2 regimes
  2. if t < 2.3500000000000001e51

    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. Taylor expanded in t around inf 99.4%

      \[\leadsto \left(\left(\log \left(x + y\right) + \log z\right) - t\right) + \color{blue}{-1 \cdot \left(\log \left(\frac{1}{t}\right) \cdot \left(a - 0.5\right)\right)} \]
    3. Taylor expanded in a around inf 49.6%

      \[\leadsto \color{blue}{-1 \cdot \left(a \cdot \log \left(\frac{1}{t}\right)\right)} \]

    if 2.3500000000000001e51 < 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 83.5%

      \[\leadsto \color{blue}{-1 \cdot t} \]
    5. Step-by-step derivation
      1. neg-mul-183.5%

        \[\leadsto \color{blue}{-t} \]
    6. Simplified83.5%

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

    \[\leadsto \begin{array}{l} \mathbf{if}\;t \leq 2.35 \cdot 10^{+51}:\\ \;\;\;\;\log \left(\frac{1}{t}\right) \cdot \left(-a\right)\\ \mathbf{else}:\\ \;\;\;\;-t\\ \end{array} \]

Alternative 11: 61.5% accurate, 3.0× speedup?

\[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;t \leq 2.7 \cdot 10^{+51}:\\ \;\;\;\;a \cdot \log t\\ \mathbf{else}:\\ \;\;\;\;-t\\ \end{array} \end{array} \]
(FPCore (x y z t a)
 :precision binary64
 (if (<= t 2.7e+51) (* a (log t)) (- t)))
double code(double x, double y, double z, double t, double a) {
	double tmp;
	if (t <= 2.7e+51) {
		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 <= 2.7d+51) 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 <= 2.7e+51) {
		tmp = a * Math.log(t);
	} else {
		tmp = -t;
	}
	return tmp;
}
def code(x, y, z, t, a):
	tmp = 0
	if t <= 2.7e+51:
		tmp = a * math.log(t)
	else:
		tmp = -t
	return tmp
function code(x, y, z, t, a)
	tmp = 0.0
	if (t <= 2.7e+51)
		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 <= 2.7e+51)
		tmp = a * log(t);
	else
		tmp = -t;
	end
	tmp_2 = tmp;
end
code[x_, y_, z_, t_, a_] := If[LessEqual[t, 2.7e+51], N[(a * N[Log[t], $MachinePrecision]), $MachinePrecision], (-t)]
\begin{array}{l}

\\
\begin{array}{l}
\mathbf{if}\;t \leq 2.7 \cdot 10^{+51}:\\
\;\;\;\;a \cdot \log t\\

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


\end{array}
\end{array}
Derivation
  1. Split input into 2 regimes
  2. if t < 2.69999999999999992e51

    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. Taylor expanded in t around inf 99.4%

      \[\leadsto \left(\left(\log \left(x + y\right) + \log z\right) - t\right) + \color{blue}{-1 \cdot \left(\log \left(\frac{1}{t}\right) \cdot \left(a - 0.5\right)\right)} \]
    3. Taylor expanded in a around inf 49.6%

      \[\leadsto \color{blue}{-1 \cdot \left(a \cdot \log \left(\frac{1}{t}\right)\right)} \]
    4. Step-by-step derivation
      1. mul-1-neg49.6%

        \[\leadsto \color{blue}{-a \cdot \log \left(\frac{1}{t}\right)} \]
      2. log-rec49.6%

        \[\leadsto -a \cdot \color{blue}{\left(-\log t\right)} \]
      3. distribute-rgt-neg-in49.6%

        \[\leadsto \color{blue}{a \cdot \left(-\left(-\log t\right)\right)} \]
      4. remove-double-neg49.6%

        \[\leadsto a \cdot \color{blue}{\log t} \]
    5. Simplified49.6%

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

    if 2.69999999999999992e51 < 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 83.5%

      \[\leadsto \color{blue}{-1 \cdot t} \]
    5. Step-by-step derivation
      1. neg-mul-183.5%

        \[\leadsto \color{blue}{-t} \]
    6. Simplified83.5%

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

    \[\leadsto \begin{array}{l} \mathbf{if}\;t \leq 2.7 \cdot 10^{+51}:\\ \;\;\;\;a \cdot \log t\\ \mathbf{else}:\\ \;\;\;\;-t\\ \end{array} \]

Alternative 12: 37.3% 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+99.6%

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

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

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

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

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

    \[\leadsto \color{blue}{\left(\log z - t\right) + \mathsf{fma}\left(a + -0.5, \log t, \log \left(x + y\right)\right)} \]
  4. Taylor expanded in t around inf 33.5%

    \[\leadsto \color{blue}{-1 \cdot t} \]
  5. Step-by-step derivation
    1. neg-mul-133.5%

      \[\leadsto \color{blue}{-t} \]
  6. Simplified33.5%

    \[\leadsto \color{blue}{-t} \]
  7. Final simplification33.5%

    \[\leadsto -t \]

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 2023320 
(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))))