Numeric.SpecFunctions:logGammaL from math-functions-0.1.5.2

Percentage Accurate: 99.6% → 99.6%
Time: 12.8s
Alternatives: 11
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 11 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?

\[\begin{array}{l} \\ \left(\left(\log \left(x + y\right) + \log z\right) - t\right) + \left(a - 0.5\right) \cdot \log t \end{array} \]
(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 99.5%

    \[\left(\left(\log \left(x + y\right) + \log z\right) - t\right) + \left(a - 0.5\right) \cdot \log t \]
  2. Add Preprocessing
  3. Add Preprocessing

Alternative 2: 85.1% accurate, 0.4× speedup?

\[\begin{array}{l} \\ \begin{array}{l} t_1 := \log \left(x + y\right) + \log z\\ \mathbf{if}\;t\_1 \leq -750 \lor \neg \left(t\_1 \leq 705\right):\\ \;\;\;\;\mathsf{fma}\left(\log t, a - 0.5, \log y\right) + \log z\\ \mathbf{else}:\\ \;\;\;\;\mathsf{fma}\left(a - 0.5, \log t, \log \left(z \cdot \left(y + x\right)\right) - t\right)\\ \end{array} \end{array} \]
(FPCore (x y z t a)
 :precision binary64
 (let* ((t_1 (+ (log (+ x y)) (log z))))
   (if (or (<= t_1 -750.0) (not (<= t_1 705.0)))
     (+ (fma (log t) (- a 0.5) (log y)) (log z))
     (fma (- a 0.5) (log t) (- (log (* z (+ y x))) t)))))
double code(double x, double y, double z, double t, double a) {
	double t_1 = log((x + y)) + log(z);
	double tmp;
	if ((t_1 <= -750.0) || !(t_1 <= 705.0)) {
		tmp = fma(log(t), (a - 0.5), log(y)) + log(z);
	} else {
		tmp = fma((a - 0.5), log(t), (log((z * (y + x))) - t));
	}
	return tmp;
}
function code(x, y, z, t, a)
	t_1 = Float64(log(Float64(x + y)) + log(z))
	tmp = 0.0
	if ((t_1 <= -750.0) || !(t_1 <= 705.0))
		tmp = Float64(fma(log(t), Float64(a - 0.5), log(y)) + log(z));
	else
		tmp = fma(Float64(a - 0.5), log(t), Float64(log(Float64(z * Float64(y + x))) - t));
	end
	return tmp
end
code[x_, y_, z_, t_, a_] := Block[{t$95$1 = N[(N[Log[N[(x + y), $MachinePrecision]], $MachinePrecision] + N[Log[z], $MachinePrecision]), $MachinePrecision]}, If[Or[LessEqual[t$95$1, -750.0], N[Not[LessEqual[t$95$1, 705.0]], $MachinePrecision]], N[(N[(N[Log[t], $MachinePrecision] * N[(a - 0.5), $MachinePrecision] + N[Log[y], $MachinePrecision]), $MachinePrecision] + N[Log[z], $MachinePrecision]), $MachinePrecision], N[(N[(a - 0.5), $MachinePrecision] * N[Log[t], $MachinePrecision] + N[(N[Log[N[(z * N[(y + x), $MachinePrecision]), $MachinePrecision]], $MachinePrecision] - t), $MachinePrecision]), $MachinePrecision]]]
\begin{array}{l}

\\
\begin{array}{l}
t_1 := \log \left(x + y\right) + \log z\\
\mathbf{if}\;t\_1 \leq -750 \lor \neg \left(t\_1 \leq 705\right):\\
\;\;\;\;\mathsf{fma}\left(\log t, a - 0.5, \log y\right) + \log z\\

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


\end{array}
\end{array}
Derivation
  1. Split input into 2 regimes
  2. if (+.f64 (log.f64 (+.f64 x y)) (log.f64 z)) < -750 or 705 < (+.f64 (log.f64 (+.f64 x y)) (log.f64 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. Add Preprocessing
    3. Taylor expanded in t around 0

      \[\leadsto \color{blue}{\log z + \left(\log \left(x + y\right) + \log t \cdot \left(a - \frac{1}{2}\right)\right)} \]
    4. Step-by-step derivation
      1. +-commutativeN/A

        \[\leadsto \color{blue}{\left(\log \left(x + y\right) + \log t \cdot \left(a - \frac{1}{2}\right)\right) + \log z} \]
      2. lower-+.f64N/A

        \[\leadsto \color{blue}{\left(\log \left(x + y\right) + \log t \cdot \left(a - \frac{1}{2}\right)\right) + \log z} \]
      3. +-commutativeN/A

        \[\leadsto \color{blue}{\left(\log t \cdot \left(a - \frac{1}{2}\right) + \log \left(x + y\right)\right)} + \log z \]
      4. distribute-rgt-out--N/A

        \[\leadsto \left(\color{blue}{\left(a \cdot \log t - \frac{1}{2} \cdot \log t\right)} + \log \left(x + y\right)\right) + \log z \]
      5. metadata-evalN/A

        \[\leadsto \left(\left(a \cdot \log t - \color{blue}{\left(\mathsf{neg}\left(\frac{-1}{2}\right)\right)} \cdot \log t\right) + \log \left(x + y\right)\right) + \log z \]
      6. fp-cancel-sign-sub-invN/A

        \[\leadsto \left(\color{blue}{\left(a \cdot \log t + \frac{-1}{2} \cdot \log t\right)} + \log \left(x + y\right)\right) + \log z \]
      7. +-commutativeN/A

        \[\leadsto \left(\color{blue}{\left(\frac{-1}{2} \cdot \log t + a \cdot \log t\right)} + \log \left(x + y\right)\right) + \log z \]
      8. distribute-rgt-outN/A

        \[\leadsto \left(\color{blue}{\log t \cdot \left(\frac{-1}{2} + a\right)} + \log \left(x + y\right)\right) + \log z \]
      9. *-commutativeN/A

        \[\leadsto \left(\color{blue}{\left(\frac{-1}{2} + a\right) \cdot \log t} + \log \left(x + y\right)\right) + \log z \]
      10. lower-fma.f64N/A

        \[\leadsto \color{blue}{\mathsf{fma}\left(\frac{-1}{2} + a, \log t, \log \left(x + y\right)\right)} + \log z \]
      11. lower-+.f64N/A

        \[\leadsto \mathsf{fma}\left(\color{blue}{\frac{-1}{2} + a}, \log t, \log \left(x + y\right)\right) + \log z \]
      12. lower-log.f64N/A

        \[\leadsto \mathsf{fma}\left(\frac{-1}{2} + a, \color{blue}{\log t}, \log \left(x + y\right)\right) + \log z \]
      13. lower-log.f64N/A

        \[\leadsto \mathsf{fma}\left(\frac{-1}{2} + a, \log t, \color{blue}{\log \left(x + y\right)}\right) + \log z \]
      14. +-commutativeN/A

        \[\leadsto \mathsf{fma}\left(\frac{-1}{2} + a, \log t, \log \color{blue}{\left(y + x\right)}\right) + \log z \]
      15. lower-+.f64N/A

        \[\leadsto \mathsf{fma}\left(\frac{-1}{2} + a, \log t, \log \color{blue}{\left(y + x\right)}\right) + \log z \]
      16. lower-log.f6470.7

        \[\leadsto \mathsf{fma}\left(-0.5 + a, \log t, \log \left(y + x\right)\right) + \color{blue}{\log z} \]
    5. Applied rewrites70.7%

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

      \[\leadsto \left(\log y + \log t \cdot \left(a - \frac{1}{2}\right)\right) + \log \color{blue}{z} \]
    7. Step-by-step derivation
      1. Applied rewrites42.6%

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

      if -750 < (+.f64 (log.f64 (+.f64 x y)) (log.f64 z)) < 705

      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. Add Preprocessing
      3. Step-by-step derivation
        1. lift-+.f64N/A

          \[\leadsto \color{blue}{\left(\left(\log \left(x + y\right) + \log z\right) - t\right) + \left(a - \frac{1}{2}\right) \cdot \log t} \]
        2. +-commutativeN/A

          \[\leadsto \color{blue}{\left(a - \frac{1}{2}\right) \cdot \log t + \left(\left(\log \left(x + y\right) + \log z\right) - t\right)} \]
        3. lift-*.f64N/A

          \[\leadsto \color{blue}{\left(a - \frac{1}{2}\right) \cdot \log t} + \left(\left(\log \left(x + y\right) + \log z\right) - t\right) \]
        4. lower-fma.f6499.5

          \[\leadsto \color{blue}{\mathsf{fma}\left(a - 0.5, \log t, \left(\log \left(x + y\right) + \log z\right) - t\right)} \]
        5. lift-+.f64N/A

          \[\leadsto \mathsf{fma}\left(a - \frac{1}{2}, \log t, \color{blue}{\left(\log \left(x + y\right) + \log z\right)} - t\right) \]
        6. lift-log.f64N/A

          \[\leadsto \mathsf{fma}\left(a - \frac{1}{2}, \log t, \left(\color{blue}{\log \left(x + y\right)} + \log z\right) - t\right) \]
        7. lift-log.f64N/A

          \[\leadsto \mathsf{fma}\left(a - \frac{1}{2}, \log t, \left(\log \left(x + y\right) + \color{blue}{\log z}\right) - t\right) \]
        8. sum-logN/A

          \[\leadsto \mathsf{fma}\left(a - \frac{1}{2}, \log t, \color{blue}{\log \left(\left(x + y\right) \cdot z\right)} - t\right) \]
        9. lower-log.f64N/A

          \[\leadsto \mathsf{fma}\left(a - \frac{1}{2}, \log t, \color{blue}{\log \left(\left(x + y\right) \cdot z\right)} - t\right) \]
        10. *-commutativeN/A

          \[\leadsto \mathsf{fma}\left(a - \frac{1}{2}, \log t, \log \color{blue}{\left(z \cdot \left(x + y\right)\right)} - t\right) \]
        11. lower-*.f6499.6

          \[\leadsto \mathsf{fma}\left(a - 0.5, \log t, \log \color{blue}{\left(z \cdot \left(x + y\right)\right)} - t\right) \]
        12. lift-+.f64N/A

          \[\leadsto \mathsf{fma}\left(a - \frac{1}{2}, \log t, \log \left(z \cdot \color{blue}{\left(x + y\right)}\right) - t\right) \]
        13. +-commutativeN/A

          \[\leadsto \mathsf{fma}\left(a - \frac{1}{2}, \log t, \log \left(z \cdot \color{blue}{\left(y + x\right)}\right) - t\right) \]
        14. lower-+.f6499.6

          \[\leadsto \mathsf{fma}\left(a - 0.5, \log t, \log \left(z \cdot \color{blue}{\left(y + x\right)}\right) - t\right) \]
      4. Applied rewrites99.6%

        \[\leadsto \color{blue}{\mathsf{fma}\left(a - 0.5, \log t, \log \left(z \cdot \left(y + x\right)\right) - t\right)} \]
    8. Recombined 2 regimes into one program.
    9. Final simplification85.6%

      \[\leadsto \begin{array}{l} \mathbf{if}\;\log \left(x + y\right) + \log z \leq -750 \lor \neg \left(\log \left(x + y\right) + \log z \leq 705\right):\\ \;\;\;\;\mathsf{fma}\left(\log t, a - 0.5, \log y\right) + \log z\\ \mathbf{else}:\\ \;\;\;\;\mathsf{fma}\left(a - 0.5, \log t, \log \left(z \cdot \left(y + x\right)\right) - t\right)\\ \end{array} \]
    10. Add Preprocessing

    Alternative 3: 90.5% accurate, 0.5× speedup?

    \[\begin{array}{l} \\ \begin{array}{l} t_1 := \log \left(x + y\right) + \log z\\ \mathbf{if}\;t\_1 \leq -750 \lor \neg \left(t\_1 \leq 700\right):\\ \;\;\;\;a \cdot \mathsf{fma}\left(t, \frac{-1}{a}, \log t\right)\\ \mathbf{else}:\\ \;\;\;\;\mathsf{fma}\left(a - 0.5, \log t, \log \left(z \cdot \left(y + x\right)\right) - t\right)\\ \end{array} \end{array} \]
    (FPCore (x y z t a)
     :precision binary64
     (let* ((t_1 (+ (log (+ x y)) (log z))))
       (if (or (<= t_1 -750.0) (not (<= t_1 700.0)))
         (* a (fma t (/ -1.0 a) (log t)))
         (fma (- a 0.5) (log t) (- (log (* z (+ y x))) t)))))
    double code(double x, double y, double z, double t, double a) {
    	double t_1 = log((x + y)) + log(z);
    	double tmp;
    	if ((t_1 <= -750.0) || !(t_1 <= 700.0)) {
    		tmp = a * fma(t, (-1.0 / a), log(t));
    	} else {
    		tmp = fma((a - 0.5), log(t), (log((z * (y + x))) - t));
    	}
    	return tmp;
    }
    
    function code(x, y, z, t, a)
    	t_1 = Float64(log(Float64(x + y)) + log(z))
    	tmp = 0.0
    	if ((t_1 <= -750.0) || !(t_1 <= 700.0))
    		tmp = Float64(a * fma(t, Float64(-1.0 / a), log(t)));
    	else
    		tmp = fma(Float64(a - 0.5), log(t), Float64(log(Float64(z * Float64(y + x))) - t));
    	end
    	return tmp
    end
    
    code[x_, y_, z_, t_, a_] := Block[{t$95$1 = N[(N[Log[N[(x + y), $MachinePrecision]], $MachinePrecision] + N[Log[z], $MachinePrecision]), $MachinePrecision]}, If[Or[LessEqual[t$95$1, -750.0], N[Not[LessEqual[t$95$1, 700.0]], $MachinePrecision]], N[(a * N[(t * N[(-1.0 / a), $MachinePrecision] + N[Log[t], $MachinePrecision]), $MachinePrecision]), $MachinePrecision], N[(N[(a - 0.5), $MachinePrecision] * N[Log[t], $MachinePrecision] + N[(N[Log[N[(z * N[(y + x), $MachinePrecision]), $MachinePrecision]], $MachinePrecision] - t), $MachinePrecision]), $MachinePrecision]]]
    
    \begin{array}{l}
    
    \\
    \begin{array}{l}
    t_1 := \log \left(x + y\right) + \log z\\
    \mathbf{if}\;t\_1 \leq -750 \lor \neg \left(t\_1 \leq 700\right):\\
    \;\;\;\;a \cdot \mathsf{fma}\left(t, \frac{-1}{a}, \log t\right)\\
    
    \mathbf{else}:\\
    \;\;\;\;\mathsf{fma}\left(a - 0.5, \log t, \log \left(z \cdot \left(y + x\right)\right) - t\right)\\
    
    
    \end{array}
    \end{array}
    
    Derivation
    1. Split input into 2 regimes
    2. if (+.f64 (log.f64 (+.f64 x y)) (log.f64 z)) < -750 or 700 < (+.f64 (log.f64 (+.f64 x y)) (log.f64 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. Add Preprocessing
      3. Taylor expanded in t around inf

        \[\leadsto \color{blue}{t \cdot \left(\left(-1 \cdot \frac{\log \left(\frac{1}{t}\right) \cdot \left(a - \frac{1}{2}\right)}{t} + \left(\frac{\log z}{t} + \frac{\log \left(x + y\right)}{t}\right)\right) - 1\right)} \]
      4. Step-by-step derivation
        1. *-commutativeN/A

          \[\leadsto \color{blue}{\left(\left(-1 \cdot \frac{\log \left(\frac{1}{t}\right) \cdot \left(a - \frac{1}{2}\right)}{t} + \left(\frac{\log z}{t} + \frac{\log \left(x + y\right)}{t}\right)\right) - 1\right) \cdot t} \]
        2. lower-*.f64N/A

          \[\leadsto \color{blue}{\left(\left(-1 \cdot \frac{\log \left(\frac{1}{t}\right) \cdot \left(a - \frac{1}{2}\right)}{t} + \left(\frac{\log z}{t} + \frac{\log \left(x + y\right)}{t}\right)\right) - 1\right) \cdot t} \]
      5. Applied rewrites83.8%

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

        \[\leadsto a \cdot \color{blue}{\left(\log t + \frac{t \cdot \left(\left(\frac{-1}{2} \cdot \frac{\log t}{t} + \left(\frac{\log z}{t} + \frac{\log \left(x + y\right)}{t}\right)\right) - 1\right)}{a}\right)} \]
      7. Step-by-step derivation
        1. Applied rewrites77.3%

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

          \[\leadsto a \cdot \mathsf{fma}\left(t, \frac{-1}{a}, \log t\right) \]
        3. Step-by-step derivation
          1. Applied rewrites59.9%

            \[\leadsto a \cdot \mathsf{fma}\left(t, \frac{-1}{a}, \log t\right) \]

          if -750 < (+.f64 (log.f64 (+.f64 x y)) (log.f64 z)) < 700

          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. Add Preprocessing
          3. Step-by-step derivation
            1. lift-+.f64N/A

              \[\leadsto \color{blue}{\left(\left(\log \left(x + y\right) + \log z\right) - t\right) + \left(a - \frac{1}{2}\right) \cdot \log t} \]
            2. +-commutativeN/A

              \[\leadsto \color{blue}{\left(a - \frac{1}{2}\right) \cdot \log t + \left(\left(\log \left(x + y\right) + \log z\right) - t\right)} \]
            3. lift-*.f64N/A

              \[\leadsto \color{blue}{\left(a - \frac{1}{2}\right) \cdot \log t} + \left(\left(\log \left(x + y\right) + \log z\right) - t\right) \]
            4. lower-fma.f6499.5

              \[\leadsto \color{blue}{\mathsf{fma}\left(a - 0.5, \log t, \left(\log \left(x + y\right) + \log z\right) - t\right)} \]
            5. lift-+.f64N/A

              \[\leadsto \mathsf{fma}\left(a - \frac{1}{2}, \log t, \color{blue}{\left(\log \left(x + y\right) + \log z\right)} - t\right) \]
            6. lift-log.f64N/A

              \[\leadsto \mathsf{fma}\left(a - \frac{1}{2}, \log t, \left(\color{blue}{\log \left(x + y\right)} + \log z\right) - t\right) \]
            7. lift-log.f64N/A

              \[\leadsto \mathsf{fma}\left(a - \frac{1}{2}, \log t, \left(\log \left(x + y\right) + \color{blue}{\log z}\right) - t\right) \]
            8. sum-logN/A

              \[\leadsto \mathsf{fma}\left(a - \frac{1}{2}, \log t, \color{blue}{\log \left(\left(x + y\right) \cdot z\right)} - t\right) \]
            9. lower-log.f64N/A

              \[\leadsto \mathsf{fma}\left(a - \frac{1}{2}, \log t, \color{blue}{\log \left(\left(x + y\right) \cdot z\right)} - t\right) \]
            10. *-commutativeN/A

              \[\leadsto \mathsf{fma}\left(a - \frac{1}{2}, \log t, \log \color{blue}{\left(z \cdot \left(x + y\right)\right)} - t\right) \]
            11. lower-*.f6499.6

              \[\leadsto \mathsf{fma}\left(a - 0.5, \log t, \log \color{blue}{\left(z \cdot \left(x + y\right)\right)} - t\right) \]
            12. lift-+.f64N/A

              \[\leadsto \mathsf{fma}\left(a - \frac{1}{2}, \log t, \log \left(z \cdot \color{blue}{\left(x + y\right)}\right) - t\right) \]
            13. +-commutativeN/A

              \[\leadsto \mathsf{fma}\left(a - \frac{1}{2}, \log t, \log \left(z \cdot \color{blue}{\left(y + x\right)}\right) - t\right) \]
            14. lower-+.f6499.6

              \[\leadsto \mathsf{fma}\left(a - 0.5, \log t, \log \left(z \cdot \color{blue}{\left(y + x\right)}\right) - t\right) \]
          4. Applied rewrites99.6%

            \[\leadsto \color{blue}{\mathsf{fma}\left(a - 0.5, \log t, \log \left(z \cdot \left(y + x\right)\right) - t\right)} \]
        4. Recombined 2 regimes into one program.
        5. Final simplification89.7%

          \[\leadsto \begin{array}{l} \mathbf{if}\;\log \left(x + y\right) + \log z \leq -750 \lor \neg \left(\log \left(x + y\right) + \log z \leq 700\right):\\ \;\;\;\;a \cdot \mathsf{fma}\left(t, \frac{-1}{a}, \log t\right)\\ \mathbf{else}:\\ \;\;\;\;\mathsf{fma}\left(a - 0.5, \log t, \log \left(z \cdot \left(y + x\right)\right) - t\right)\\ \end{array} \]
        6. Add Preprocessing

        Alternative 4: 64.9% accurate, 0.5× speedup?

        \[\begin{array}{l} \\ \begin{array}{l} t_1 := \log \left(x + y\right) + \log z\\ \mathbf{if}\;t\_1 \leq -750 \lor \neg \left(t\_1 \leq 700\right):\\ \;\;\;\;a \cdot \mathsf{fma}\left(t, \frac{-1}{a}, \log t\right)\\ \mathbf{else}:\\ \;\;\;\;\mathsf{fma}\left(-0.5 + a, \log t, \log \left(z \cdot y\right) - t\right)\\ \end{array} \end{array} \]
        (FPCore (x y z t a)
         :precision binary64
         (let* ((t_1 (+ (log (+ x y)) (log z))))
           (if (or (<= t_1 -750.0) (not (<= t_1 700.0)))
             (* a (fma t (/ -1.0 a) (log t)))
             (fma (+ -0.5 a) (log t) (- (log (* z y)) t)))))
        double code(double x, double y, double z, double t, double a) {
        	double t_1 = log((x + y)) + log(z);
        	double tmp;
        	if ((t_1 <= -750.0) || !(t_1 <= 700.0)) {
        		tmp = a * fma(t, (-1.0 / a), log(t));
        	} else {
        		tmp = fma((-0.5 + a), log(t), (log((z * y)) - t));
        	}
        	return tmp;
        }
        
        function code(x, y, z, t, a)
        	t_1 = Float64(log(Float64(x + y)) + log(z))
        	tmp = 0.0
        	if ((t_1 <= -750.0) || !(t_1 <= 700.0))
        		tmp = Float64(a * fma(t, Float64(-1.0 / a), log(t)));
        	else
        		tmp = fma(Float64(-0.5 + a), log(t), Float64(log(Float64(z * y)) - t));
        	end
        	return tmp
        end
        
        code[x_, y_, z_, t_, a_] := Block[{t$95$1 = N[(N[Log[N[(x + y), $MachinePrecision]], $MachinePrecision] + N[Log[z], $MachinePrecision]), $MachinePrecision]}, If[Or[LessEqual[t$95$1, -750.0], N[Not[LessEqual[t$95$1, 700.0]], $MachinePrecision]], N[(a * N[(t * N[(-1.0 / a), $MachinePrecision] + N[Log[t], $MachinePrecision]), $MachinePrecision]), $MachinePrecision], N[(N[(-0.5 + a), $MachinePrecision] * N[Log[t], $MachinePrecision] + N[(N[Log[N[(z * y), $MachinePrecision]], $MachinePrecision] - t), $MachinePrecision]), $MachinePrecision]]]
        
        \begin{array}{l}
        
        \\
        \begin{array}{l}
        t_1 := \log \left(x + y\right) + \log z\\
        \mathbf{if}\;t\_1 \leq -750 \lor \neg \left(t\_1 \leq 700\right):\\
        \;\;\;\;a \cdot \mathsf{fma}\left(t, \frac{-1}{a}, \log t\right)\\
        
        \mathbf{else}:\\
        \;\;\;\;\mathsf{fma}\left(-0.5 + a, \log t, \log \left(z \cdot y\right) - t\right)\\
        
        
        \end{array}
        \end{array}
        
        Derivation
        1. Split input into 2 regimes
        2. if (+.f64 (log.f64 (+.f64 x y)) (log.f64 z)) < -750 or 700 < (+.f64 (log.f64 (+.f64 x y)) (log.f64 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. Add Preprocessing
          3. Taylor expanded in t around inf

            \[\leadsto \color{blue}{t \cdot \left(\left(-1 \cdot \frac{\log \left(\frac{1}{t}\right) \cdot \left(a - \frac{1}{2}\right)}{t} + \left(\frac{\log z}{t} + \frac{\log \left(x + y\right)}{t}\right)\right) - 1\right)} \]
          4. Step-by-step derivation
            1. *-commutativeN/A

              \[\leadsto \color{blue}{\left(\left(-1 \cdot \frac{\log \left(\frac{1}{t}\right) \cdot \left(a - \frac{1}{2}\right)}{t} + \left(\frac{\log z}{t} + \frac{\log \left(x + y\right)}{t}\right)\right) - 1\right) \cdot t} \]
            2. lower-*.f64N/A

              \[\leadsto \color{blue}{\left(\left(-1 \cdot \frac{\log \left(\frac{1}{t}\right) \cdot \left(a - \frac{1}{2}\right)}{t} + \left(\frac{\log z}{t} + \frac{\log \left(x + y\right)}{t}\right)\right) - 1\right) \cdot t} \]
          5. Applied rewrites83.8%

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

            \[\leadsto a \cdot \color{blue}{\left(\log t + \frac{t \cdot \left(\left(\frac{-1}{2} \cdot \frac{\log t}{t} + \left(\frac{\log z}{t} + \frac{\log \left(x + y\right)}{t}\right)\right) - 1\right)}{a}\right)} \]
          7. Step-by-step derivation
            1. Applied rewrites77.3%

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

              \[\leadsto a \cdot \mathsf{fma}\left(t, \frac{-1}{a}, \log t\right) \]
            3. Step-by-step derivation
              1. Applied rewrites59.9%

                \[\leadsto a \cdot \mathsf{fma}\left(t, \frac{-1}{a}, \log t\right) \]

              if -750 < (+.f64 (log.f64 (+.f64 x y)) (log.f64 z)) < 700

              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. Add Preprocessing
              3. Taylor expanded in x around 0

                \[\leadsto \color{blue}{\left(\log y + \left(\log z + \log t \cdot \left(a - \frac{1}{2}\right)\right)\right) - t} \]
              4. Step-by-step derivation
                1. +-commutativeN/A

                  \[\leadsto \color{blue}{\left(\left(\log z + \log t \cdot \left(a - \frac{1}{2}\right)\right) + \log y\right)} - t \]
                2. associate--l+N/A

                  \[\leadsto \color{blue}{\left(\log z + \log t \cdot \left(a - \frac{1}{2}\right)\right) + \left(\log y - t\right)} \]
                3. lower-+.f64N/A

                  \[\leadsto \color{blue}{\left(\log z + \log t \cdot \left(a - \frac{1}{2}\right)\right) + \left(\log y - t\right)} \]
                4. +-commutativeN/A

                  \[\leadsto \color{blue}{\left(\log t \cdot \left(a - \frac{1}{2}\right) + \log z\right)} + \left(\log y - t\right) \]
                5. distribute-rgt-out--N/A

                  \[\leadsto \left(\color{blue}{\left(a \cdot \log t - \frac{1}{2} \cdot \log t\right)} + \log z\right) + \left(\log y - t\right) \]
                6. metadata-evalN/A

                  \[\leadsto \left(\left(a \cdot \log t - \color{blue}{\left(\mathsf{neg}\left(\frac{-1}{2}\right)\right)} \cdot \log t\right) + \log z\right) + \left(\log y - t\right) \]
                7. fp-cancel-sign-sub-invN/A

                  \[\leadsto \left(\color{blue}{\left(a \cdot \log t + \frac{-1}{2} \cdot \log t\right)} + \log z\right) + \left(\log y - t\right) \]
                8. distribute-rgt-outN/A

                  \[\leadsto \left(\color{blue}{\log t \cdot \left(a + \frac{-1}{2}\right)} + \log z\right) + \left(\log y - t\right) \]
                9. +-commutativeN/A

                  \[\leadsto \left(\log t \cdot \color{blue}{\left(\frac{-1}{2} + a\right)} + \log z\right) + \left(\log y - t\right) \]
                10. *-commutativeN/A

                  \[\leadsto \left(\color{blue}{\left(\frac{-1}{2} + a\right) \cdot \log t} + \log z\right) + \left(\log y - t\right) \]
                11. lower-fma.f64N/A

                  \[\leadsto \color{blue}{\mathsf{fma}\left(\frac{-1}{2} + a, \log t, \log z\right)} + \left(\log y - t\right) \]
                12. lower-+.f64N/A

                  \[\leadsto \mathsf{fma}\left(\color{blue}{\frac{-1}{2} + a}, \log t, \log z\right) + \left(\log y - t\right) \]
                13. lower-log.f64N/A

                  \[\leadsto \mathsf{fma}\left(\frac{-1}{2} + a, \color{blue}{\log t}, \log z\right) + \left(\log y - t\right) \]
                14. lower-log.f64N/A

                  \[\leadsto \mathsf{fma}\left(\frac{-1}{2} + a, \log t, \color{blue}{\log z}\right) + \left(\log y - t\right) \]
                15. lower--.f64N/A

                  \[\leadsto \mathsf{fma}\left(\frac{-1}{2} + a, \log t, \log z\right) + \color{blue}{\left(\log y - t\right)} \]
                16. lower-log.f6469.8

                  \[\leadsto \mathsf{fma}\left(-0.5 + a, \log t, \log z\right) + \left(\color{blue}{\log y} - t\right) \]
              5. Applied rewrites69.8%

                \[\leadsto \color{blue}{\mathsf{fma}\left(-0.5 + a, \log t, \log z\right) + \left(\log y - t\right)} \]
              6. Step-by-step derivation
                1. Applied rewrites66.7%

                  \[\leadsto \mathsf{fma}\left(-0.5 + a, \color{blue}{\log t}, \log \left(z \cdot y\right) - t\right) \]
              7. Recombined 2 regimes into one program.
              8. Final simplification65.0%

                \[\leadsto \begin{array}{l} \mathbf{if}\;\log \left(x + y\right) + \log z \leq -750 \lor \neg \left(\log \left(x + y\right) + \log z \leq 700\right):\\ \;\;\;\;a \cdot \mathsf{fma}\left(t, \frac{-1}{a}, \log t\right)\\ \mathbf{else}:\\ \;\;\;\;\mathsf{fma}\left(-0.5 + a, \log t, \log \left(z \cdot y\right) - t\right)\\ \end{array} \]
              9. Add Preprocessing

              Alternative 5: 80.5% accurate, 1.0× speedup?

              \[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;a \leq -6.8 \lor \neg \left(a \leq 3.4\right):\\ \;\;\;\;a \cdot \mathsf{fma}\left(t, \frac{-1}{a}, \log t\right)\\ \mathbf{else}:\\ \;\;\;\;\mathsf{fma}\left(-0.5, \log t, \log z\right) + \left(\log y - t\right)\\ \end{array} \end{array} \]
              (FPCore (x y z t a)
               :precision binary64
               (if (or (<= a -6.8) (not (<= a 3.4)))
                 (* a (fma t (/ -1.0 a) (log t)))
                 (+ (fma -0.5 (log t) (log z)) (- (log y) t))))
              double code(double x, double y, double z, double t, double a) {
              	double tmp;
              	if ((a <= -6.8) || !(a <= 3.4)) {
              		tmp = a * fma(t, (-1.0 / a), log(t));
              	} else {
              		tmp = fma(-0.5, log(t), log(z)) + (log(y) - t);
              	}
              	return tmp;
              }
              
              function code(x, y, z, t, a)
              	tmp = 0.0
              	if ((a <= -6.8) || !(a <= 3.4))
              		tmp = Float64(a * fma(t, Float64(-1.0 / a), log(t)));
              	else
              		tmp = Float64(fma(-0.5, log(t), log(z)) + Float64(log(y) - t));
              	end
              	return tmp
              end
              
              code[x_, y_, z_, t_, a_] := If[Or[LessEqual[a, -6.8], N[Not[LessEqual[a, 3.4]], $MachinePrecision]], N[(a * N[(t * N[(-1.0 / a), $MachinePrecision] + N[Log[t], $MachinePrecision]), $MachinePrecision]), $MachinePrecision], N[(N[(-0.5 * N[Log[t], $MachinePrecision] + N[Log[z], $MachinePrecision]), $MachinePrecision] + N[(N[Log[y], $MachinePrecision] - t), $MachinePrecision]), $MachinePrecision]]
              
              \begin{array}{l}
              
              \\
              \begin{array}{l}
              \mathbf{if}\;a \leq -6.8 \lor \neg \left(a \leq 3.4\right):\\
              \;\;\;\;a \cdot \mathsf{fma}\left(t, \frac{-1}{a}, \log t\right)\\
              
              \mathbf{else}:\\
              \;\;\;\;\mathsf{fma}\left(-0.5, \log t, \log z\right) + \left(\log y - t\right)\\
              
              
              \end{array}
              \end{array}
              
              Derivation
              1. Split input into 2 regimes
              2. if a < -6.79999999999999982 or 3.39999999999999991 < 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. Add Preprocessing
                3. Taylor expanded in t around inf

                  \[\leadsto \color{blue}{t \cdot \left(\left(-1 \cdot \frac{\log \left(\frac{1}{t}\right) \cdot \left(a - \frac{1}{2}\right)}{t} + \left(\frac{\log z}{t} + \frac{\log \left(x + y\right)}{t}\right)\right) - 1\right)} \]
                4. Step-by-step derivation
                  1. *-commutativeN/A

                    \[\leadsto \color{blue}{\left(\left(-1 \cdot \frac{\log \left(\frac{1}{t}\right) \cdot \left(a - \frac{1}{2}\right)}{t} + \left(\frac{\log z}{t} + \frac{\log \left(x + y\right)}{t}\right)\right) - 1\right) \cdot t} \]
                  2. lower-*.f64N/A

                    \[\leadsto \color{blue}{\left(\left(-1 \cdot \frac{\log \left(\frac{1}{t}\right) \cdot \left(a - \frac{1}{2}\right)}{t} + \left(\frac{\log z}{t} + \frac{\log \left(x + y\right)}{t}\right)\right) - 1\right) \cdot t} \]
                5. Applied rewrites76.8%

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

                  \[\leadsto a \cdot \color{blue}{\left(\log t + \frac{t \cdot \left(\left(\frac{-1}{2} \cdot \frac{\log t}{t} + \left(\frac{\log z}{t} + \frac{\log \left(x + y\right)}{t}\right)\right) - 1\right)}{a}\right)} \]
                7. Step-by-step derivation
                  1. Applied rewrites99.4%

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

                    \[\leadsto a \cdot \mathsf{fma}\left(t, \frac{-1}{a}, \log t\right) \]
                  3. Step-by-step derivation
                    1. Applied rewrites97.1%

                      \[\leadsto a \cdot \mathsf{fma}\left(t, \frac{-1}{a}, \log t\right) \]

                    if -6.79999999999999982 < a < 3.39999999999999991

                    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. Add Preprocessing
                    3. Taylor expanded in x around 0

                      \[\leadsto \color{blue}{\left(\log y + \left(\log z + \log t \cdot \left(a - \frac{1}{2}\right)\right)\right) - t} \]
                    4. Step-by-step derivation
                      1. +-commutativeN/A

                        \[\leadsto \color{blue}{\left(\left(\log z + \log t \cdot \left(a - \frac{1}{2}\right)\right) + \log y\right)} - t \]
                      2. associate--l+N/A

                        \[\leadsto \color{blue}{\left(\log z + \log t \cdot \left(a - \frac{1}{2}\right)\right) + \left(\log y - t\right)} \]
                      3. lower-+.f64N/A

                        \[\leadsto \color{blue}{\left(\log z + \log t \cdot \left(a - \frac{1}{2}\right)\right) + \left(\log y - t\right)} \]
                      4. +-commutativeN/A

                        \[\leadsto \color{blue}{\left(\log t \cdot \left(a - \frac{1}{2}\right) + \log z\right)} + \left(\log y - t\right) \]
                      5. distribute-rgt-out--N/A

                        \[\leadsto \left(\color{blue}{\left(a \cdot \log t - \frac{1}{2} \cdot \log t\right)} + \log z\right) + \left(\log y - t\right) \]
                      6. metadata-evalN/A

                        \[\leadsto \left(\left(a \cdot \log t - \color{blue}{\left(\mathsf{neg}\left(\frac{-1}{2}\right)\right)} \cdot \log t\right) + \log z\right) + \left(\log y - t\right) \]
                      7. fp-cancel-sign-sub-invN/A

                        \[\leadsto \left(\color{blue}{\left(a \cdot \log t + \frac{-1}{2} \cdot \log t\right)} + \log z\right) + \left(\log y - t\right) \]
                      8. distribute-rgt-outN/A

                        \[\leadsto \left(\color{blue}{\log t \cdot \left(a + \frac{-1}{2}\right)} + \log z\right) + \left(\log y - t\right) \]
                      9. +-commutativeN/A

                        \[\leadsto \left(\log t \cdot \color{blue}{\left(\frac{-1}{2} + a\right)} + \log z\right) + \left(\log y - t\right) \]
                      10. *-commutativeN/A

                        \[\leadsto \left(\color{blue}{\left(\frac{-1}{2} + a\right) \cdot \log t} + \log z\right) + \left(\log y - t\right) \]
                      11. lower-fma.f64N/A

                        \[\leadsto \color{blue}{\mathsf{fma}\left(\frac{-1}{2} + a, \log t, \log z\right)} + \left(\log y - t\right) \]
                      12. lower-+.f64N/A

                        \[\leadsto \mathsf{fma}\left(\color{blue}{\frac{-1}{2} + a}, \log t, \log z\right) + \left(\log y - t\right) \]
                      13. lower-log.f64N/A

                        \[\leadsto \mathsf{fma}\left(\frac{-1}{2} + a, \color{blue}{\log t}, \log z\right) + \left(\log y - t\right) \]
                      14. lower-log.f64N/A

                        \[\leadsto \mathsf{fma}\left(\frac{-1}{2} + a, \log t, \color{blue}{\log z}\right) + \left(\log y - t\right) \]
                      15. lower--.f64N/A

                        \[\leadsto \mathsf{fma}\left(\frac{-1}{2} + a, \log t, \log z\right) + \color{blue}{\left(\log y - t\right)} \]
                      16. lower-log.f6464.2

                        \[\leadsto \mathsf{fma}\left(-0.5 + a, \log t, \log z\right) + \left(\color{blue}{\log y} - t\right) \]
                    5. Applied rewrites64.2%

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

                      \[\leadsto \mathsf{fma}\left(\frac{-1}{2}, \log t, \log z\right) + \left(\log \color{blue}{y} - t\right) \]
                    7. Step-by-step derivation
                      1. Applied rewrites63.7%

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

                      \[\leadsto \begin{array}{l} \mathbf{if}\;a \leq -6.8 \lor \neg \left(a \leq 3.4\right):\\ \;\;\;\;a \cdot \mathsf{fma}\left(t, \frac{-1}{a}, \log t\right)\\ \mathbf{else}:\\ \;\;\;\;\mathsf{fma}\left(-0.5, \log t, \log z\right) + \left(\log y - t\right)\\ \end{array} \]
                    10. Add Preprocessing

                    Alternative 6: 69.1% accurate, 1.0× speedup?

                    \[\begin{array}{l} \\ \mathsf{fma}\left(-0.5 + a, \log t, \log z\right) + \left(\log y - t\right) \end{array} \]
                    (FPCore (x y z t a)
                     :precision binary64
                     (+ (fma (+ -0.5 a) (log t) (log z)) (- (log y) t)))
                    double code(double x, double y, double z, double t, double a) {
                    	return fma((-0.5 + a), log(t), log(z)) + (log(y) - t);
                    }
                    
                    function code(x, y, z, t, a)
                    	return Float64(fma(Float64(-0.5 + a), log(t), log(z)) + Float64(log(y) - t))
                    end
                    
                    code[x_, y_, z_, t_, a_] := N[(N[(N[(-0.5 + a), $MachinePrecision] * N[Log[t], $MachinePrecision] + N[Log[z], $MachinePrecision]), $MachinePrecision] + N[(N[Log[y], $MachinePrecision] - t), $MachinePrecision]), $MachinePrecision]
                    
                    \begin{array}{l}
                    
                    \\
                    \mathsf{fma}\left(-0.5 + a, \log t, \log z\right) + \left(\log y - t\right)
                    \end{array}
                    
                    Derivation
                    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. Add Preprocessing
                    3. Taylor expanded in x around 0

                      \[\leadsto \color{blue}{\left(\log y + \left(\log z + \log t \cdot \left(a - \frac{1}{2}\right)\right)\right) - t} \]
                    4. Step-by-step derivation
                      1. +-commutativeN/A

                        \[\leadsto \color{blue}{\left(\left(\log z + \log t \cdot \left(a - \frac{1}{2}\right)\right) + \log y\right)} - t \]
                      2. associate--l+N/A

                        \[\leadsto \color{blue}{\left(\log z + \log t \cdot \left(a - \frac{1}{2}\right)\right) + \left(\log y - t\right)} \]
                      3. lower-+.f64N/A

                        \[\leadsto \color{blue}{\left(\log z + \log t \cdot \left(a - \frac{1}{2}\right)\right) + \left(\log y - t\right)} \]
                      4. +-commutativeN/A

                        \[\leadsto \color{blue}{\left(\log t \cdot \left(a - \frac{1}{2}\right) + \log z\right)} + \left(\log y - t\right) \]
                      5. distribute-rgt-out--N/A

                        \[\leadsto \left(\color{blue}{\left(a \cdot \log t - \frac{1}{2} \cdot \log t\right)} + \log z\right) + \left(\log y - t\right) \]
                      6. metadata-evalN/A

                        \[\leadsto \left(\left(a \cdot \log t - \color{blue}{\left(\mathsf{neg}\left(\frac{-1}{2}\right)\right)} \cdot \log t\right) + \log z\right) + \left(\log y - t\right) \]
                      7. fp-cancel-sign-sub-invN/A

                        \[\leadsto \left(\color{blue}{\left(a \cdot \log t + \frac{-1}{2} \cdot \log t\right)} + \log z\right) + \left(\log y - t\right) \]
                      8. distribute-rgt-outN/A

                        \[\leadsto \left(\color{blue}{\log t \cdot \left(a + \frac{-1}{2}\right)} + \log z\right) + \left(\log y - t\right) \]
                      9. +-commutativeN/A

                        \[\leadsto \left(\log t \cdot \color{blue}{\left(\frac{-1}{2} + a\right)} + \log z\right) + \left(\log y - t\right) \]
                      10. *-commutativeN/A

                        \[\leadsto \left(\color{blue}{\left(\frac{-1}{2} + a\right) \cdot \log t} + \log z\right) + \left(\log y - t\right) \]
                      11. lower-fma.f64N/A

                        \[\leadsto \color{blue}{\mathsf{fma}\left(\frac{-1}{2} + a, \log t, \log z\right)} + \left(\log y - t\right) \]
                      12. lower-+.f64N/A

                        \[\leadsto \mathsf{fma}\left(\color{blue}{\frac{-1}{2} + a}, \log t, \log z\right) + \left(\log y - t\right) \]
                      13. lower-log.f64N/A

                        \[\leadsto \mathsf{fma}\left(\frac{-1}{2} + a, \color{blue}{\log t}, \log z\right) + \left(\log y - t\right) \]
                      14. lower-log.f64N/A

                        \[\leadsto \mathsf{fma}\left(\frac{-1}{2} + a, \log t, \color{blue}{\log z}\right) + \left(\log y - t\right) \]
                      15. lower--.f64N/A

                        \[\leadsto \mathsf{fma}\left(\frac{-1}{2} + a, \log t, \log z\right) + \color{blue}{\left(\log y - t\right)} \]
                      16. lower-log.f6468.3

                        \[\leadsto \mathsf{fma}\left(-0.5 + a, \log t, \log z\right) + \left(\color{blue}{\log y} - t\right) \]
                    5. Applied rewrites68.3%

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

                    Alternative 7: 83.2% accurate, 1.2× speedup?

                    \[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;a - 0.5 \leq -1000000 \lor \neg \left(a - 0.5 \leq -0.4\right):\\ \;\;\;\;a \cdot \mathsf{fma}\left(t, \frac{-1}{a}, \log t\right)\\ \mathbf{else}:\\ \;\;\;\;\left(\frac{\log \left(\sqrt{{t}^{-1}} \cdot \left(\left(y + x\right) \cdot z\right)\right)}{t} - 1\right) \cdot t\\ \end{array} \end{array} \]
                    (FPCore (x y z t a)
                     :precision binary64
                     (if (or (<= (- a 0.5) -1000000.0) (not (<= (- a 0.5) -0.4)))
                       (* a (fma t (/ -1.0 a) (log t)))
                       (* (- (/ (log (* (sqrt (pow t -1.0)) (* (+ y x) z))) t) 1.0) t)))
                    double code(double x, double y, double z, double t, double a) {
                    	double tmp;
                    	if (((a - 0.5) <= -1000000.0) || !((a - 0.5) <= -0.4)) {
                    		tmp = a * fma(t, (-1.0 / a), log(t));
                    	} else {
                    		tmp = ((log((sqrt(pow(t, -1.0)) * ((y + x) * z))) / t) - 1.0) * t;
                    	}
                    	return tmp;
                    }
                    
                    function code(x, y, z, t, a)
                    	tmp = 0.0
                    	if ((Float64(a - 0.5) <= -1000000.0) || !(Float64(a - 0.5) <= -0.4))
                    		tmp = Float64(a * fma(t, Float64(-1.0 / a), log(t)));
                    	else
                    		tmp = Float64(Float64(Float64(log(Float64(sqrt((t ^ -1.0)) * Float64(Float64(y + x) * z))) / t) - 1.0) * t);
                    	end
                    	return tmp
                    end
                    
                    code[x_, y_, z_, t_, a_] := If[Or[LessEqual[N[(a - 0.5), $MachinePrecision], -1000000.0], N[Not[LessEqual[N[(a - 0.5), $MachinePrecision], -0.4]], $MachinePrecision]], N[(a * N[(t * N[(-1.0 / a), $MachinePrecision] + N[Log[t], $MachinePrecision]), $MachinePrecision]), $MachinePrecision], N[(N[(N[(N[Log[N[(N[Sqrt[N[Power[t, -1.0], $MachinePrecision]], $MachinePrecision] * N[(N[(y + x), $MachinePrecision] * z), $MachinePrecision]), $MachinePrecision]], $MachinePrecision] / t), $MachinePrecision] - 1.0), $MachinePrecision] * t), $MachinePrecision]]
                    
                    \begin{array}{l}
                    
                    \\
                    \begin{array}{l}
                    \mathbf{if}\;a - 0.5 \leq -1000000 \lor \neg \left(a - 0.5 \leq -0.4\right):\\
                    \;\;\;\;a \cdot \mathsf{fma}\left(t, \frac{-1}{a}, \log t\right)\\
                    
                    \mathbf{else}:\\
                    \;\;\;\;\left(\frac{\log \left(\sqrt{{t}^{-1}} \cdot \left(\left(y + x\right) \cdot z\right)\right)}{t} - 1\right) \cdot t\\
                    
                    
                    \end{array}
                    \end{array}
                    
                    Derivation
                    1. Split input into 2 regimes
                    2. if (-.f64 a #s(literal 1/2 binary64)) < -1e6 or -0.40000000000000002 < (-.f64 a #s(literal 1/2 binary64))

                      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. Add Preprocessing
                      3. Taylor expanded in t around inf

                        \[\leadsto \color{blue}{t \cdot \left(\left(-1 \cdot \frac{\log \left(\frac{1}{t}\right) \cdot \left(a - \frac{1}{2}\right)}{t} + \left(\frac{\log z}{t} + \frac{\log \left(x + y\right)}{t}\right)\right) - 1\right)} \]
                      4. Step-by-step derivation
                        1. *-commutativeN/A

                          \[\leadsto \color{blue}{\left(\left(-1 \cdot \frac{\log \left(\frac{1}{t}\right) \cdot \left(a - \frac{1}{2}\right)}{t} + \left(\frac{\log z}{t} + \frac{\log \left(x + y\right)}{t}\right)\right) - 1\right) \cdot t} \]
                        2. lower-*.f64N/A

                          \[\leadsto \color{blue}{\left(\left(-1 \cdot \frac{\log \left(\frac{1}{t}\right) \cdot \left(a - \frac{1}{2}\right)}{t} + \left(\frac{\log z}{t} + \frac{\log \left(x + y\right)}{t}\right)\right) - 1\right) \cdot t} \]
                      5. Applied rewrites76.8%

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

                        \[\leadsto a \cdot \color{blue}{\left(\log t + \frac{t \cdot \left(\left(\frac{-1}{2} \cdot \frac{\log t}{t} + \left(\frac{\log z}{t} + \frac{\log \left(x + y\right)}{t}\right)\right) - 1\right)}{a}\right)} \]
                      7. Step-by-step derivation
                        1. Applied rewrites99.4%

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

                          \[\leadsto a \cdot \mathsf{fma}\left(t, \frac{-1}{a}, \log t\right) \]
                        3. Step-by-step derivation
                          1. Applied rewrites97.1%

                            \[\leadsto a \cdot \mathsf{fma}\left(t, \frac{-1}{a}, \log t\right) \]

                          if -1e6 < (-.f64 a #s(literal 1/2 binary64)) < -0.40000000000000002

                          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. Add Preprocessing
                          3. Taylor expanded in t around inf

                            \[\leadsto \color{blue}{t \cdot \left(\left(-1 \cdot \frac{\log \left(\frac{1}{t}\right) \cdot \left(a - \frac{1}{2}\right)}{t} + \left(\frac{\log z}{t} + \frac{\log \left(x + y\right)}{t}\right)\right) - 1\right)} \]
                          4. Step-by-step derivation
                            1. *-commutativeN/A

                              \[\leadsto \color{blue}{\left(\left(-1 \cdot \frac{\log \left(\frac{1}{t}\right) \cdot \left(a - \frac{1}{2}\right)}{t} + \left(\frac{\log z}{t} + \frac{\log \left(x + y\right)}{t}\right)\right) - 1\right) \cdot t} \]
                            2. lower-*.f64N/A

                              \[\leadsto \color{blue}{\left(\left(-1 \cdot \frac{\log \left(\frac{1}{t}\right) \cdot \left(a - \frac{1}{2}\right)}{t} + \left(\frac{\log z}{t} + \frac{\log \left(x + y\right)}{t}\right)\right) - 1\right) \cdot t} \]
                          5. Applied rewrites99.5%

                            \[\leadsto \color{blue}{\left(\frac{\mathsf{fma}\left(-0.5 + a, \log t, \log \left(y + x\right)\right) + \log z}{t} - 1\right) \cdot t} \]
                          6. Step-by-step derivation
                            1. Applied rewrites70.4%

                              \[\leadsto \left(\frac{\log \left({t}^{\left(-0.5 + a\right)} \cdot \left(\left(y + x\right) \cdot z\right)\right)}{t} - 1\right) \cdot t \]
                            2. Taylor expanded in a around 0

                              \[\leadsto \left(\frac{\log \left(\sqrt{\frac{1}{t}} \cdot \left(\left(y + x\right) \cdot z\right)\right)}{t} - 1\right) \cdot t \]
                            3. Step-by-step derivation
                              1. Applied rewrites69.6%

                                \[\leadsto \left(\frac{\log \left(\sqrt{\frac{1}{t}} \cdot \left(\left(y + x\right) \cdot z\right)\right)}{t} - 1\right) \cdot t \]
                            4. Recombined 2 regimes into one program.
                            5. Final simplification83.6%

                              \[\leadsto \begin{array}{l} \mathbf{if}\;a - 0.5 \leq -1000000 \lor \neg \left(a - 0.5 \leq -0.4\right):\\ \;\;\;\;a \cdot \mathsf{fma}\left(t, \frac{-1}{a}, \log t\right)\\ \mathbf{else}:\\ \;\;\;\;\left(\frac{\log \left(\sqrt{{t}^{-1}} \cdot \left(\left(y + x\right) \cdot z\right)\right)}{t} - 1\right) \cdot t\\ \end{array} \]
                            6. Add Preprocessing

                            Alternative 8: 71.2% accurate, 1.4× speedup?

                            \[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;a - 0.5 \leq -1000000 \lor \neg \left(a - 0.5 \leq -0.4\right):\\ \;\;\;\;a \cdot \mathsf{fma}\left(t, \frac{-1}{a}, \log t\right)\\ \mathbf{else}:\\ \;\;\;\;\log \left(y \cdot \left({t}^{\left(-0.5 + a\right)} \cdot z\right)\right) - t\\ \end{array} \end{array} \]
                            (FPCore (x y z t a)
                             :precision binary64
                             (if (or (<= (- a 0.5) -1000000.0) (not (<= (- a 0.5) -0.4)))
                               (* a (fma t (/ -1.0 a) (log t)))
                               (- (log (* y (* (pow t (+ -0.5 a)) z))) t)))
                            double code(double x, double y, double z, double t, double a) {
                            	double tmp;
                            	if (((a - 0.5) <= -1000000.0) || !((a - 0.5) <= -0.4)) {
                            		tmp = a * fma(t, (-1.0 / a), log(t));
                            	} else {
                            		tmp = log((y * (pow(t, (-0.5 + a)) * z))) - t;
                            	}
                            	return tmp;
                            }
                            
                            function code(x, y, z, t, a)
                            	tmp = 0.0
                            	if ((Float64(a - 0.5) <= -1000000.0) || !(Float64(a - 0.5) <= -0.4))
                            		tmp = Float64(a * fma(t, Float64(-1.0 / a), log(t)));
                            	else
                            		tmp = Float64(log(Float64(y * Float64((t ^ Float64(-0.5 + a)) * z))) - t);
                            	end
                            	return tmp
                            end
                            
                            code[x_, y_, z_, t_, a_] := If[Or[LessEqual[N[(a - 0.5), $MachinePrecision], -1000000.0], N[Not[LessEqual[N[(a - 0.5), $MachinePrecision], -0.4]], $MachinePrecision]], N[(a * N[(t * N[(-1.0 / a), $MachinePrecision] + N[Log[t], $MachinePrecision]), $MachinePrecision]), $MachinePrecision], N[(N[Log[N[(y * N[(N[Power[t, N[(-0.5 + a), $MachinePrecision]], $MachinePrecision] * z), $MachinePrecision]), $MachinePrecision]], $MachinePrecision] - t), $MachinePrecision]]
                            
                            \begin{array}{l}
                            
                            \\
                            \begin{array}{l}
                            \mathbf{if}\;a - 0.5 \leq -1000000 \lor \neg \left(a - 0.5 \leq -0.4\right):\\
                            \;\;\;\;a \cdot \mathsf{fma}\left(t, \frac{-1}{a}, \log t\right)\\
                            
                            \mathbf{else}:\\
                            \;\;\;\;\log \left(y \cdot \left({t}^{\left(-0.5 + a\right)} \cdot z\right)\right) - t\\
                            
                            
                            \end{array}
                            \end{array}
                            
                            Derivation
                            1. Split input into 2 regimes
                            2. if (-.f64 a #s(literal 1/2 binary64)) < -1e6 or -0.40000000000000002 < (-.f64 a #s(literal 1/2 binary64))

                              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. Add Preprocessing
                              3. Taylor expanded in t around inf

                                \[\leadsto \color{blue}{t \cdot \left(\left(-1 \cdot \frac{\log \left(\frac{1}{t}\right) \cdot \left(a - \frac{1}{2}\right)}{t} + \left(\frac{\log z}{t} + \frac{\log \left(x + y\right)}{t}\right)\right) - 1\right)} \]
                              4. Step-by-step derivation
                                1. *-commutativeN/A

                                  \[\leadsto \color{blue}{\left(\left(-1 \cdot \frac{\log \left(\frac{1}{t}\right) \cdot \left(a - \frac{1}{2}\right)}{t} + \left(\frac{\log z}{t} + \frac{\log \left(x + y\right)}{t}\right)\right) - 1\right) \cdot t} \]
                                2. lower-*.f64N/A

                                  \[\leadsto \color{blue}{\left(\left(-1 \cdot \frac{\log \left(\frac{1}{t}\right) \cdot \left(a - \frac{1}{2}\right)}{t} + \left(\frac{\log z}{t} + \frac{\log \left(x + y\right)}{t}\right)\right) - 1\right) \cdot t} \]
                              5. Applied rewrites76.8%

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

                                \[\leadsto a \cdot \color{blue}{\left(\log t + \frac{t \cdot \left(\left(\frac{-1}{2} \cdot \frac{\log t}{t} + \left(\frac{\log z}{t} + \frac{\log \left(x + y\right)}{t}\right)\right) - 1\right)}{a}\right)} \]
                              7. Step-by-step derivation
                                1. Applied rewrites99.4%

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

                                  \[\leadsto a \cdot \mathsf{fma}\left(t, \frac{-1}{a}, \log t\right) \]
                                3. Step-by-step derivation
                                  1. Applied rewrites97.1%

                                    \[\leadsto a \cdot \mathsf{fma}\left(t, \frac{-1}{a}, \log t\right) \]

                                  if -1e6 < (-.f64 a #s(literal 1/2 binary64)) < -0.40000000000000002

                                  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. Add Preprocessing
                                  3. Taylor expanded in x around 0

                                    \[\leadsto \color{blue}{\left(\log y + \left(\log z + \log t \cdot \left(a - \frac{1}{2}\right)\right)\right) - t} \]
                                  4. Step-by-step derivation
                                    1. +-commutativeN/A

                                      \[\leadsto \color{blue}{\left(\left(\log z + \log t \cdot \left(a - \frac{1}{2}\right)\right) + \log y\right)} - t \]
                                    2. associate--l+N/A

                                      \[\leadsto \color{blue}{\left(\log z + \log t \cdot \left(a - \frac{1}{2}\right)\right) + \left(\log y - t\right)} \]
                                    3. lower-+.f64N/A

                                      \[\leadsto \color{blue}{\left(\log z + \log t \cdot \left(a - \frac{1}{2}\right)\right) + \left(\log y - t\right)} \]
                                    4. +-commutativeN/A

                                      \[\leadsto \color{blue}{\left(\log t \cdot \left(a - \frac{1}{2}\right) + \log z\right)} + \left(\log y - t\right) \]
                                    5. distribute-rgt-out--N/A

                                      \[\leadsto \left(\color{blue}{\left(a \cdot \log t - \frac{1}{2} \cdot \log t\right)} + \log z\right) + \left(\log y - t\right) \]
                                    6. metadata-evalN/A

                                      \[\leadsto \left(\left(a \cdot \log t - \color{blue}{\left(\mathsf{neg}\left(\frac{-1}{2}\right)\right)} \cdot \log t\right) + \log z\right) + \left(\log y - t\right) \]
                                    7. fp-cancel-sign-sub-invN/A

                                      \[\leadsto \left(\color{blue}{\left(a \cdot \log t + \frac{-1}{2} \cdot \log t\right)} + \log z\right) + \left(\log y - t\right) \]
                                    8. distribute-rgt-outN/A

                                      \[\leadsto \left(\color{blue}{\log t \cdot \left(a + \frac{-1}{2}\right)} + \log z\right) + \left(\log y - t\right) \]
                                    9. +-commutativeN/A

                                      \[\leadsto \left(\log t \cdot \color{blue}{\left(\frac{-1}{2} + a\right)} + \log z\right) + \left(\log y - t\right) \]
                                    10. *-commutativeN/A

                                      \[\leadsto \left(\color{blue}{\left(\frac{-1}{2} + a\right) \cdot \log t} + \log z\right) + \left(\log y - t\right) \]
                                    11. lower-fma.f64N/A

                                      \[\leadsto \color{blue}{\mathsf{fma}\left(\frac{-1}{2} + a, \log t, \log z\right)} + \left(\log y - t\right) \]
                                    12. lower-+.f64N/A

                                      \[\leadsto \mathsf{fma}\left(\color{blue}{\frac{-1}{2} + a}, \log t, \log z\right) + \left(\log y - t\right) \]
                                    13. lower-log.f64N/A

                                      \[\leadsto \mathsf{fma}\left(\frac{-1}{2} + a, \color{blue}{\log t}, \log z\right) + \left(\log y - t\right) \]
                                    14. lower-log.f64N/A

                                      \[\leadsto \mathsf{fma}\left(\frac{-1}{2} + a, \log t, \color{blue}{\log z}\right) + \left(\log y - t\right) \]
                                    15. lower--.f64N/A

                                      \[\leadsto \mathsf{fma}\left(\frac{-1}{2} + a, \log t, \log z\right) + \color{blue}{\left(\log y - t\right)} \]
                                    16. lower-log.f6464.2

                                      \[\leadsto \mathsf{fma}\left(-0.5 + a, \log t, \log z\right) + \left(\color{blue}{\log y} - t\right) \]
                                  5. Applied rewrites64.2%

                                    \[\leadsto \color{blue}{\mathsf{fma}\left(-0.5 + a, \log t, \log z\right) + \left(\log y - t\right)} \]
                                  6. Step-by-step derivation
                                    1. Applied rewrites50.3%

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

                                    \[\leadsto \begin{array}{l} \mathbf{if}\;a - 0.5 \leq -1000000 \lor \neg \left(a - 0.5 \leq -0.4\right):\\ \;\;\;\;a \cdot \mathsf{fma}\left(t, \frac{-1}{a}, \log t\right)\\ \mathbf{else}:\\ \;\;\;\;\log \left(y \cdot \left({t}^{\left(-0.5 + a\right)} \cdot z\right)\right) - t\\ \end{array} \]
                                  9. Add Preprocessing

                                  Alternative 9: 74.1% accurate, 2.4× speedup?

                                  \[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;a \leq -7.8 \cdot 10^{-64} \lor \neg \left(a \leq 0.0003\right):\\ \;\;\;\;a \cdot \mathsf{fma}\left(t, \frac{-1}{a}, \log t\right)\\ \mathbf{else}:\\ \;\;\;\;-t\\ \end{array} \end{array} \]
                                  (FPCore (x y z t a)
                                   :precision binary64
                                   (if (or (<= a -7.8e-64) (not (<= a 0.0003)))
                                     (* a (fma t (/ -1.0 a) (log t)))
                                     (- t)))
                                  double code(double x, double y, double z, double t, double a) {
                                  	double tmp;
                                  	if ((a <= -7.8e-64) || !(a <= 0.0003)) {
                                  		tmp = a * fma(t, (-1.0 / a), log(t));
                                  	} else {
                                  		tmp = -t;
                                  	}
                                  	return tmp;
                                  }
                                  
                                  function code(x, y, z, t, a)
                                  	tmp = 0.0
                                  	if ((a <= -7.8e-64) || !(a <= 0.0003))
                                  		tmp = Float64(a * fma(t, Float64(-1.0 / a), log(t)));
                                  	else
                                  		tmp = Float64(-t);
                                  	end
                                  	return tmp
                                  end
                                  
                                  code[x_, y_, z_, t_, a_] := If[Or[LessEqual[a, -7.8e-64], N[Not[LessEqual[a, 0.0003]], $MachinePrecision]], N[(a * N[(t * N[(-1.0 / a), $MachinePrecision] + N[Log[t], $MachinePrecision]), $MachinePrecision]), $MachinePrecision], (-t)]
                                  
                                  \begin{array}{l}
                                  
                                  \\
                                  \begin{array}{l}
                                  \mathbf{if}\;a \leq -7.8 \cdot 10^{-64} \lor \neg \left(a \leq 0.0003\right):\\
                                  \;\;\;\;a \cdot \mathsf{fma}\left(t, \frac{-1}{a}, \log t\right)\\
                                  
                                  \mathbf{else}:\\
                                  \;\;\;\;-t\\
                                  
                                  
                                  \end{array}
                                  \end{array}
                                  
                                  Derivation
                                  1. Split input into 2 regimes
                                  2. if a < -7.7999999999999994e-64 or 2.99999999999999974e-4 < 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. Add Preprocessing
                                    3. Taylor expanded in t around inf

                                      \[\leadsto \color{blue}{t \cdot \left(\left(-1 \cdot \frac{\log \left(\frac{1}{t}\right) \cdot \left(a - \frac{1}{2}\right)}{t} + \left(\frac{\log z}{t} + \frac{\log \left(x + y\right)}{t}\right)\right) - 1\right)} \]
                                    4. Step-by-step derivation
                                      1. *-commutativeN/A

                                        \[\leadsto \color{blue}{\left(\left(-1 \cdot \frac{\log \left(\frac{1}{t}\right) \cdot \left(a - \frac{1}{2}\right)}{t} + \left(\frac{\log z}{t} + \frac{\log \left(x + y\right)}{t}\right)\right) - 1\right) \cdot t} \]
                                      2. lower-*.f64N/A

                                        \[\leadsto \color{blue}{\left(\left(-1 \cdot \frac{\log \left(\frac{1}{t}\right) \cdot \left(a - \frac{1}{2}\right)}{t} + \left(\frac{\log z}{t} + \frac{\log \left(x + y\right)}{t}\right)\right) - 1\right) \cdot t} \]
                                    5. Applied rewrites79.2%

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

                                      \[\leadsto a \cdot \color{blue}{\left(\log t + \frac{t \cdot \left(\left(\frac{-1}{2} \cdot \frac{\log t}{t} + \left(\frac{\log z}{t} + \frac{\log \left(x + y\right)}{t}\right)\right) - 1\right)}{a}\right)} \]
                                    7. Step-by-step derivation
                                      1. Applied rewrites99.4%

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

                                        \[\leadsto a \cdot \mathsf{fma}\left(t, \frac{-1}{a}, \log t\right) \]
                                      3. Step-by-step derivation
                                        1. Applied rewrites93.6%

                                          \[\leadsto a \cdot \mathsf{fma}\left(t, \frac{-1}{a}, \log t\right) \]

                                        if -7.7999999999999994e-64 < a < 2.99999999999999974e-4

                                        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. Add Preprocessing
                                        3. Taylor expanded in t around inf

                                          \[\leadsto \color{blue}{-1 \cdot t} \]
                                        4. Step-by-step derivation
                                          1. mul-1-negN/A

                                            \[\leadsto \color{blue}{\mathsf{neg}\left(t\right)} \]
                                          2. lower-neg.f6450.1

                                            \[\leadsto \color{blue}{-t} \]
                                        5. Applied rewrites50.1%

                                          \[\leadsto \color{blue}{-t} \]
                                      4. Recombined 2 regimes into one program.
                                      5. Final simplification75.1%

                                        \[\leadsto \begin{array}{l} \mathbf{if}\;a \leq -7.8 \cdot 10^{-64} \lor \neg \left(a \leq 0.0003\right):\\ \;\;\;\;a \cdot \mathsf{fma}\left(t, \frac{-1}{a}, \log t\right)\\ \mathbf{else}:\\ \;\;\;\;-t\\ \end{array} \]
                                      6. Add Preprocessing

                                      Alternative 10: 62.5% accurate, 2.9× speedup?

                                      \[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;t \leq 10^{+28}:\\ \;\;\;\;\log t \cdot a\\ \mathbf{else}:\\ \;\;\;\;-t\\ \end{array} \end{array} \]
                                      (FPCore (x y z t a) :precision binary64 (if (<= t 1e+28) (* (log t) a) (- t)))
                                      double code(double x, double y, double z, double t, double a) {
                                      	double tmp;
                                      	if (t <= 1e+28) {
                                      		tmp = log(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 <= 1d+28) then
                                              tmp = log(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 <= 1e+28) {
                                      		tmp = Math.log(t) * a;
                                      	} else {
                                      		tmp = -t;
                                      	}
                                      	return tmp;
                                      }
                                      
                                      def code(x, y, z, t, a):
                                      	tmp = 0
                                      	if t <= 1e+28:
                                      		tmp = math.log(t) * a
                                      	else:
                                      		tmp = -t
                                      	return tmp
                                      
                                      function code(x, y, z, t, a)
                                      	tmp = 0.0
                                      	if (t <= 1e+28)
                                      		tmp = Float64(log(t) * a);
                                      	else
                                      		tmp = Float64(-t);
                                      	end
                                      	return tmp
                                      end
                                      
                                      function tmp_2 = code(x, y, z, t, a)
                                      	tmp = 0.0;
                                      	if (t <= 1e+28)
                                      		tmp = log(t) * a;
                                      	else
                                      		tmp = -t;
                                      	end
                                      	tmp_2 = tmp;
                                      end
                                      
                                      code[x_, y_, z_, t_, a_] := If[LessEqual[t, 1e+28], N[(N[Log[t], $MachinePrecision] * a), $MachinePrecision], (-t)]
                                      
                                      \begin{array}{l}
                                      
                                      \\
                                      \begin{array}{l}
                                      \mathbf{if}\;t \leq 10^{+28}:\\
                                      \;\;\;\;\log t \cdot a\\
                                      
                                      \mathbf{else}:\\
                                      \;\;\;\;-t\\
                                      
                                      
                                      \end{array}
                                      \end{array}
                                      
                                      Derivation
                                      1. Split input into 2 regimes
                                      2. if t < 9.99999999999999958e27

                                        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. Add Preprocessing
                                        3. Taylor expanded in a around inf

                                          \[\leadsto \color{blue}{a \cdot \log t} \]
                                        4. Step-by-step derivation
                                          1. *-commutativeN/A

                                            \[\leadsto \color{blue}{\log t \cdot a} \]
                                          2. lower-*.f64N/A

                                            \[\leadsto \color{blue}{\log t \cdot a} \]
                                          3. lower-log.f6455.7

                                            \[\leadsto \color{blue}{\log t} \cdot a \]
                                        5. Applied rewrites55.7%

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

                                        if 9.99999999999999958e27 < 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. Add Preprocessing
                                        3. Taylor expanded in t around inf

                                          \[\leadsto \color{blue}{-1 \cdot t} \]
                                        4. Step-by-step derivation
                                          1. mul-1-negN/A

                                            \[\leadsto \color{blue}{\mathsf{neg}\left(t\right)} \]
                                          2. lower-neg.f6480.0

                                            \[\leadsto \color{blue}{-t} \]
                                        5. Applied rewrites80.0%

                                          \[\leadsto \color{blue}{-t} \]
                                      3. Recombined 2 regimes into one program.
                                      4. Add Preprocessing

                                      Alternative 11: 38.0% accurate, 107.0× 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 99.5%

                                        \[\left(\left(\log \left(x + y\right) + \log z\right) - t\right) + \left(a - 0.5\right) \cdot \log t \]
                                      2. Add Preprocessing
                                      3. Taylor expanded in t around inf

                                        \[\leadsto \color{blue}{-1 \cdot t} \]
                                      4. Step-by-step derivation
                                        1. mul-1-negN/A

                                          \[\leadsto \color{blue}{\mathsf{neg}\left(t\right)} \]
                                        2. lower-neg.f6436.4

                                          \[\leadsto \color{blue}{-t} \]
                                      5. Applied rewrites36.4%

                                        \[\leadsto \color{blue}{-t} \]
                                      6. Add Preprocessing

                                      Developer Target 1: 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 2024339 
                                      (FPCore (x y z t a)
                                        :name "Numeric.SpecFunctions:logGammaL from math-functions-0.1.5.2"
                                        :precision binary64
                                      
                                        :alt
                                        (! :herbie-platform default (+ (log (+ x y)) (+ (- (log z) t) (* (- a 1/2) (log t)))))
                                      
                                        (+ (- (+ (log (+ x y)) (log z)) t) (* (- a 0.5) (log t))))