System.Random.MWC.Distributions:gamma from mwc-random-0.13.3.2

Percentage Accurate: 99.9% → 99.9%
Time: 10.7s
Alternatives: 8
Speedup: 1.0×

Specification

?
\[\begin{array}{l} \\ x \cdot 0.5 + y \cdot \left(\left(1 - z\right) + \log z\right) \end{array} \]
(FPCore (x y z) :precision binary64 (+ (* x 0.5) (* y (+ (- 1.0 z) (log z)))))
double code(double x, double y, double z) {
	return (x * 0.5) + (y * ((1.0 - z) + log(z)));
}
real(8) function code(x, y, z)
    real(8), intent (in) :: x
    real(8), intent (in) :: y
    real(8), intent (in) :: z
    code = (x * 0.5d0) + (y * ((1.0d0 - z) + log(z)))
end function
public static double code(double x, double y, double z) {
	return (x * 0.5) + (y * ((1.0 - z) + Math.log(z)));
}
def code(x, y, z):
	return (x * 0.5) + (y * ((1.0 - z) + math.log(z)))
function code(x, y, z)
	return Float64(Float64(x * 0.5) + Float64(y * Float64(Float64(1.0 - z) + log(z))))
end
function tmp = code(x, y, z)
	tmp = (x * 0.5) + (y * ((1.0 - z) + log(z)));
end
code[x_, y_, z_] := N[(N[(x * 0.5), $MachinePrecision] + N[(y * N[(N[(1.0 - z), $MachinePrecision] + N[Log[z], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}

\\
x \cdot 0.5 + y \cdot \left(\left(1 - z\right) + \log z\right)
\end{array}

Sampling outcomes in binary64 precision:

Local Percentage Accuracy vs ?

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

Accuracy vs Speed?

Herbie found 8 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: 99.9% accurate, 1.0× speedup?

\[\begin{array}{l} \\ x \cdot 0.5 + y \cdot \left(\left(1 - z\right) + \log z\right) \end{array} \]
(FPCore (x y z) :precision binary64 (+ (* x 0.5) (* y (+ (- 1.0 z) (log z)))))
double code(double x, double y, double z) {
	return (x * 0.5) + (y * ((1.0 - z) + log(z)));
}
real(8) function code(x, y, z)
    real(8), intent (in) :: x
    real(8), intent (in) :: y
    real(8), intent (in) :: z
    code = (x * 0.5d0) + (y * ((1.0d0 - z) + log(z)))
end function
public static double code(double x, double y, double z) {
	return (x * 0.5) + (y * ((1.0 - z) + Math.log(z)));
}
def code(x, y, z):
	return (x * 0.5) + (y * ((1.0 - z) + math.log(z)))
function code(x, y, z)
	return Float64(Float64(x * 0.5) + Float64(y * Float64(Float64(1.0 - z) + log(z))))
end
function tmp = code(x, y, z)
	tmp = (x * 0.5) + (y * ((1.0 - z) + log(z)));
end
code[x_, y_, z_] := N[(N[(x * 0.5), $MachinePrecision] + N[(y * N[(N[(1.0 - z), $MachinePrecision] + N[Log[z], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}

\\
x \cdot 0.5 + y \cdot \left(\left(1 - z\right) + \log z\right)
\end{array}

Alternative 1: 99.9% accurate, 1.0× speedup?

\[\begin{array}{l} \\ \mathsf{fma}\left(\left(1 + \log z\right) - z, y, x \cdot 0.5\right) \end{array} \]
(FPCore (x y z) :precision binary64 (fma (- (+ 1.0 (log z)) z) y (* x 0.5)))
double code(double x, double y, double z) {
	return fma(((1.0 + log(z)) - z), y, (x * 0.5));
}
function code(x, y, z)
	return fma(Float64(Float64(1.0 + log(z)) - z), y, Float64(x * 0.5))
end
code[x_, y_, z_] := N[(N[(N[(1.0 + N[Log[z], $MachinePrecision]), $MachinePrecision] - z), $MachinePrecision] * y + N[(x * 0.5), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}

\\
\mathsf{fma}\left(\left(1 + \log z\right) - z, y, x \cdot 0.5\right)
\end{array}
Derivation
  1. Initial program 99.9%

    \[x \cdot 0.5 + y \cdot \left(\left(1 - z\right) + \log z\right) \]
  2. Add Preprocessing
  3. Step-by-step derivation
    1. lift-+.f64N/A

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

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

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

      \[\leadsto \color{blue}{\left(\left(1 - z\right) + \log z\right) \cdot y} + x \cdot \frac{1}{2} \]
    5. lower-fma.f6499.9

      \[\leadsto \color{blue}{\mathsf{fma}\left(\left(1 - z\right) + \log z, y, x \cdot 0.5\right)} \]
    6. lift-+.f64N/A

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

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

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

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

      \[\leadsto \mathsf{fma}\left(\color{blue}{\left(\log z + 1\right) - z}, y, x \cdot \frac{1}{2}\right) \]
    11. lower-+.f6499.9

      \[\leadsto \mathsf{fma}\left(\color{blue}{\left(\log z + 1\right)} - z, y, x \cdot 0.5\right) \]
    12. lift-*.f64N/A

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

      \[\leadsto \mathsf{fma}\left(\left(\log z + 1\right) - z, y, \color{blue}{\frac{1}{2} \cdot x}\right) \]
    14. lower-*.f6499.9

      \[\leadsto \mathsf{fma}\left(\left(\log z + 1\right) - z, y, \color{blue}{0.5 \cdot x}\right) \]
  4. Applied rewrites99.9%

    \[\leadsto \color{blue}{\mathsf{fma}\left(\left(\log z + 1\right) - z, y, 0.5 \cdot x\right)} \]
  5. Final simplification99.9%

    \[\leadsto \mathsf{fma}\left(\left(1 + \log z\right) - z, y, x \cdot 0.5\right) \]
  6. Add Preprocessing

Alternative 2: 59.9% accurate, 0.5× speedup?

\[\begin{array}{l} \\ \begin{array}{l} t_0 := \left(\left(1 - z\right) + \log z\right) \cdot y\\ t_1 := \left(-z\right) \cdot y\\ \mathbf{if}\;t\_0 \leq -1 \cdot 10^{+115}:\\ \;\;\;\;t\_1\\ \mathbf{elif}\;t\_0 \leq 4 \cdot 10^{+14}:\\ \;\;\;\;x \cdot 0.5\\ \mathbf{else}:\\ \;\;\;\;t\_1\\ \end{array} \end{array} \]
(FPCore (x y z)
 :precision binary64
 (let* ((t_0 (* (+ (- 1.0 z) (log z)) y)) (t_1 (* (- z) y)))
   (if (<= t_0 -1e+115) t_1 (if (<= t_0 4e+14) (* x 0.5) t_1))))
double code(double x, double y, double z) {
	double t_0 = ((1.0 - z) + log(z)) * y;
	double t_1 = -z * y;
	double tmp;
	if (t_0 <= -1e+115) {
		tmp = t_1;
	} else if (t_0 <= 4e+14) {
		tmp = x * 0.5;
	} else {
		tmp = t_1;
	}
	return tmp;
}
real(8) function code(x, y, z)
    real(8), intent (in) :: x
    real(8), intent (in) :: y
    real(8), intent (in) :: z
    real(8) :: t_0
    real(8) :: t_1
    real(8) :: tmp
    t_0 = ((1.0d0 - z) + log(z)) * y
    t_1 = -z * y
    if (t_0 <= (-1d+115)) then
        tmp = t_1
    else if (t_0 <= 4d+14) then
        tmp = x * 0.5d0
    else
        tmp = t_1
    end if
    code = tmp
end function
public static double code(double x, double y, double z) {
	double t_0 = ((1.0 - z) + Math.log(z)) * y;
	double t_1 = -z * y;
	double tmp;
	if (t_0 <= -1e+115) {
		tmp = t_1;
	} else if (t_0 <= 4e+14) {
		tmp = x * 0.5;
	} else {
		tmp = t_1;
	}
	return tmp;
}
def code(x, y, z):
	t_0 = ((1.0 - z) + math.log(z)) * y
	t_1 = -z * y
	tmp = 0
	if t_0 <= -1e+115:
		tmp = t_1
	elif t_0 <= 4e+14:
		tmp = x * 0.5
	else:
		tmp = t_1
	return tmp
function code(x, y, z)
	t_0 = Float64(Float64(Float64(1.0 - z) + log(z)) * y)
	t_1 = Float64(Float64(-z) * y)
	tmp = 0.0
	if (t_0 <= -1e+115)
		tmp = t_1;
	elseif (t_0 <= 4e+14)
		tmp = Float64(x * 0.5);
	else
		tmp = t_1;
	end
	return tmp
end
function tmp_2 = code(x, y, z)
	t_0 = ((1.0 - z) + log(z)) * y;
	t_1 = -z * y;
	tmp = 0.0;
	if (t_0 <= -1e+115)
		tmp = t_1;
	elseif (t_0 <= 4e+14)
		tmp = x * 0.5;
	else
		tmp = t_1;
	end
	tmp_2 = tmp;
end
code[x_, y_, z_] := Block[{t$95$0 = N[(N[(N[(1.0 - z), $MachinePrecision] + N[Log[z], $MachinePrecision]), $MachinePrecision] * y), $MachinePrecision]}, Block[{t$95$1 = N[((-z) * y), $MachinePrecision]}, If[LessEqual[t$95$0, -1e+115], t$95$1, If[LessEqual[t$95$0, 4e+14], N[(x * 0.5), $MachinePrecision], t$95$1]]]]
\begin{array}{l}

\\
\begin{array}{l}
t_0 := \left(\left(1 - z\right) + \log z\right) \cdot y\\
t_1 := \left(-z\right) \cdot y\\
\mathbf{if}\;t\_0 \leq -1 \cdot 10^{+115}:\\
\;\;\;\;t\_1\\

\mathbf{elif}\;t\_0 \leq 4 \cdot 10^{+14}:\\
\;\;\;\;x \cdot 0.5\\

\mathbf{else}:\\
\;\;\;\;t\_1\\


\end{array}
\end{array}
Derivation
  1. Split input into 2 regimes
  2. if (*.f64 y (+.f64 (-.f64 #s(literal 1 binary64) z) (log.f64 z))) < -1e115 or 4e14 < (*.f64 y (+.f64 (-.f64 #s(literal 1 binary64) z) (log.f64 z)))

    1. Initial program 99.8%

      \[x \cdot 0.5 + y \cdot \left(\left(1 - z\right) + \log z\right) \]
    2. Add Preprocessing
    3. Taylor expanded in z around inf

      \[\leadsto \color{blue}{-1 \cdot \left(y \cdot z\right)} \]
    4. Step-by-step derivation
      1. mul-1-negN/A

        \[\leadsto \color{blue}{\mathsf{neg}\left(y \cdot z\right)} \]
      2. *-commutativeN/A

        \[\leadsto \mathsf{neg}\left(\color{blue}{z \cdot y}\right) \]
      3. distribute-lft-neg-inN/A

        \[\leadsto \color{blue}{\left(\mathsf{neg}\left(z\right)\right) \cdot y} \]
      4. lower-*.f64N/A

        \[\leadsto \color{blue}{\left(\mathsf{neg}\left(z\right)\right) \cdot y} \]
      5. lower-neg.f6452.5

        \[\leadsto \color{blue}{\left(-z\right)} \cdot y \]
    5. Applied rewrites52.5%

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

    if -1e115 < (*.f64 y (+.f64 (-.f64 #s(literal 1 binary64) z) (log.f64 z))) < 4e14

    1. Initial program 99.9%

      \[x \cdot 0.5 + y \cdot \left(\left(1 - z\right) + \log z\right) \]
    2. Add Preprocessing
    3. Taylor expanded in y around 0

      \[\leadsto \color{blue}{\frac{1}{2} \cdot x} \]
    4. Step-by-step derivation
      1. *-commutativeN/A

        \[\leadsto \color{blue}{x \cdot \frac{1}{2}} \]
      2. lower-*.f6467.7

        \[\leadsto \color{blue}{x \cdot 0.5} \]
    5. Applied rewrites67.7%

      \[\leadsto \color{blue}{x \cdot 0.5} \]
  3. Recombined 2 regimes into one program.
  4. Final simplification59.3%

    \[\leadsto \begin{array}{l} \mathbf{if}\;\left(\left(1 - z\right) + \log z\right) \cdot y \leq -1 \cdot 10^{+115}:\\ \;\;\;\;\left(-z\right) \cdot y\\ \mathbf{elif}\;\left(\left(1 - z\right) + \log z\right) \cdot y \leq 4 \cdot 10^{+14}:\\ \;\;\;\;x \cdot 0.5\\ \mathbf{else}:\\ \;\;\;\;\left(-z\right) \cdot y\\ \end{array} \]
  5. Add Preprocessing

Alternative 3: 98.5% accurate, 0.5× speedup?

\[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;\left(1 - z\right) + \log z \leq -50000:\\ \;\;\;\;\mathsf{fma}\left(-z, y, x \cdot 0.5\right)\\ \mathbf{else}:\\ \;\;\;\;\mathsf{fma}\left(x, 0.5, \mathsf{fma}\left(\log z, y, y\right)\right)\\ \end{array} \end{array} \]
(FPCore (x y z)
 :precision binary64
 (if (<= (+ (- 1.0 z) (log z)) -50000.0)
   (fma (- z) y (* x 0.5))
   (fma x 0.5 (fma (log z) y y))))
double code(double x, double y, double z) {
	double tmp;
	if (((1.0 - z) + log(z)) <= -50000.0) {
		tmp = fma(-z, y, (x * 0.5));
	} else {
		tmp = fma(x, 0.5, fma(log(z), y, y));
	}
	return tmp;
}
function code(x, y, z)
	tmp = 0.0
	if (Float64(Float64(1.0 - z) + log(z)) <= -50000.0)
		tmp = fma(Float64(-z), y, Float64(x * 0.5));
	else
		tmp = fma(x, 0.5, fma(log(z), y, y));
	end
	return tmp
end
code[x_, y_, z_] := If[LessEqual[N[(N[(1.0 - z), $MachinePrecision] + N[Log[z], $MachinePrecision]), $MachinePrecision], -50000.0], N[((-z) * y + N[(x * 0.5), $MachinePrecision]), $MachinePrecision], N[(x * 0.5 + N[(N[Log[z], $MachinePrecision] * y + y), $MachinePrecision]), $MachinePrecision]]
\begin{array}{l}

\\
\begin{array}{l}
\mathbf{if}\;\left(1 - z\right) + \log z \leq -50000:\\
\;\;\;\;\mathsf{fma}\left(-z, y, x \cdot 0.5\right)\\

\mathbf{else}:\\
\;\;\;\;\mathsf{fma}\left(x, 0.5, \mathsf{fma}\left(\log z, y, y\right)\right)\\


\end{array}
\end{array}
Derivation
  1. Split input into 2 regimes
  2. if (+.f64 (-.f64 #s(literal 1 binary64) z) (log.f64 z)) < -5e4

    1. Initial program 99.9%

      \[x \cdot 0.5 + y \cdot \left(\left(1 - z\right) + \log z\right) \]
    2. Add Preprocessing
    3. Step-by-step derivation
      1. lift-+.f64N/A

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

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

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

        \[\leadsto \color{blue}{\left(\left(1 - z\right) + \log z\right) \cdot y} + x \cdot \frac{1}{2} \]
      5. lower-fma.f64100.0

        \[\leadsto \color{blue}{\mathsf{fma}\left(\left(1 - z\right) + \log z, y, x \cdot 0.5\right)} \]
      6. lift-+.f64N/A

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

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

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

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

        \[\leadsto \mathsf{fma}\left(\color{blue}{\left(\log z + 1\right) - z}, y, x \cdot \frac{1}{2}\right) \]
      11. lower-+.f64100.0

        \[\leadsto \mathsf{fma}\left(\color{blue}{\left(\log z + 1\right)} - z, y, x \cdot 0.5\right) \]
      12. lift-*.f64N/A

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

        \[\leadsto \mathsf{fma}\left(\left(\log z + 1\right) - z, y, \color{blue}{\frac{1}{2} \cdot x}\right) \]
      14. lower-*.f64100.0

        \[\leadsto \mathsf{fma}\left(\left(\log z + 1\right) - z, y, \color{blue}{0.5 \cdot x}\right) \]
    4. Applied rewrites100.0%

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

      \[\leadsto \mathsf{fma}\left(\color{blue}{-1 \cdot z}, y, \frac{1}{2} \cdot x\right) \]
    6. Step-by-step derivation
      1. mul-1-negN/A

        \[\leadsto \mathsf{fma}\left(\color{blue}{\mathsf{neg}\left(z\right)}, y, \frac{1}{2} \cdot x\right) \]
      2. lower-neg.f6498.7

        \[\leadsto \mathsf{fma}\left(\color{blue}{-z}, y, 0.5 \cdot x\right) \]
    7. Applied rewrites98.7%

      \[\leadsto \mathsf{fma}\left(\color{blue}{-z}, y, 0.5 \cdot x\right) \]

    if -5e4 < (+.f64 (-.f64 #s(literal 1 binary64) z) (log.f64 z))

    1. Initial program 99.8%

      \[x \cdot 0.5 + y \cdot \left(\left(1 - z\right) + \log z\right) \]
    2. Add Preprocessing
    3. Taylor expanded in z around 0

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

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

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

        \[\leadsto \mathsf{fma}\left(x, \frac{1}{2}, y \cdot \color{blue}{\left(\log z + 1\right)}\right) \]
      4. distribute-rgt-inN/A

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

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

        \[\leadsto \mathsf{fma}\left(x, \frac{1}{2}, \color{blue}{\mathsf{fma}\left(\log z, y, y\right)}\right) \]
      7. lower-log.f6498.4

        \[\leadsto \mathsf{fma}\left(x, 0.5, \mathsf{fma}\left(\color{blue}{\log z}, y, y\right)\right) \]
    5. Applied rewrites98.4%

      \[\leadsto \color{blue}{\mathsf{fma}\left(x, 0.5, \mathsf{fma}\left(\log z, y, y\right)\right)} \]
  3. Recombined 2 regimes into one program.
  4. Final simplification98.5%

    \[\leadsto \begin{array}{l} \mathbf{if}\;\left(1 - z\right) + \log z \leq -50000:\\ \;\;\;\;\mathsf{fma}\left(-z, y, x \cdot 0.5\right)\\ \mathbf{else}:\\ \;\;\;\;\mathsf{fma}\left(x, 0.5, \mathsf{fma}\left(\log z, y, y\right)\right)\\ \end{array} \]
  5. Add Preprocessing

Alternative 4: 74.0% accurate, 0.5× speedup?

\[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;\left(1 - z\right) + \log z \leq -340:\\ \;\;\;\;\mathsf{fma}\left(-z, y, x \cdot 0.5\right)\\ \mathbf{else}:\\ \;\;\;\;\mathsf{fma}\left(\log z, y, y\right)\\ \end{array} \end{array} \]
(FPCore (x y z)
 :precision binary64
 (if (<= (+ (- 1.0 z) (log z)) -340.0)
   (fma (- z) y (* x 0.5))
   (fma (log z) y y)))
double code(double x, double y, double z) {
	double tmp;
	if (((1.0 - z) + log(z)) <= -340.0) {
		tmp = fma(-z, y, (x * 0.5));
	} else {
		tmp = fma(log(z), y, y);
	}
	return tmp;
}
function code(x, y, z)
	tmp = 0.0
	if (Float64(Float64(1.0 - z) + log(z)) <= -340.0)
		tmp = fma(Float64(-z), y, Float64(x * 0.5));
	else
		tmp = fma(log(z), y, y);
	end
	return tmp
end
code[x_, y_, z_] := If[LessEqual[N[(N[(1.0 - z), $MachinePrecision] + N[Log[z], $MachinePrecision]), $MachinePrecision], -340.0], N[((-z) * y + N[(x * 0.5), $MachinePrecision]), $MachinePrecision], N[(N[Log[z], $MachinePrecision] * y + y), $MachinePrecision]]
\begin{array}{l}

\\
\begin{array}{l}
\mathbf{if}\;\left(1 - z\right) + \log z \leq -340:\\
\;\;\;\;\mathsf{fma}\left(-z, y, x \cdot 0.5\right)\\

\mathbf{else}:\\
\;\;\;\;\mathsf{fma}\left(\log z, y, y\right)\\


\end{array}
\end{array}
Derivation
  1. Split input into 2 regimes
  2. if (+.f64 (-.f64 #s(literal 1 binary64) z) (log.f64 z)) < -340

    1. Initial program 99.9%

      \[x \cdot 0.5 + y \cdot \left(\left(1 - z\right) + \log z\right) \]
    2. Add Preprocessing
    3. Step-by-step derivation
      1. lift-+.f64N/A

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

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

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

        \[\leadsto \color{blue}{\left(\left(1 - z\right) + \log z\right) \cdot y} + x \cdot \frac{1}{2} \]
      5. lower-fma.f6499.9

        \[\leadsto \color{blue}{\mathsf{fma}\left(\left(1 - z\right) + \log z, y, x \cdot 0.5\right)} \]
      6. lift-+.f64N/A

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

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

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

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

        \[\leadsto \mathsf{fma}\left(\color{blue}{\left(\log z + 1\right) - z}, y, x \cdot \frac{1}{2}\right) \]
      11. lower-+.f6499.9

        \[\leadsto \mathsf{fma}\left(\color{blue}{\left(\log z + 1\right)} - z, y, x \cdot 0.5\right) \]
      12. lift-*.f64N/A

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

        \[\leadsto \mathsf{fma}\left(\left(\log z + 1\right) - z, y, \color{blue}{\frac{1}{2} \cdot x}\right) \]
      14. lower-*.f6499.9

        \[\leadsto \mathsf{fma}\left(\left(\log z + 1\right) - z, y, \color{blue}{0.5 \cdot x}\right) \]
    4. Applied rewrites99.9%

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

      \[\leadsto \mathsf{fma}\left(\color{blue}{-1 \cdot z}, y, \frac{1}{2} \cdot x\right) \]
    6. Step-by-step derivation
      1. mul-1-negN/A

        \[\leadsto \mathsf{fma}\left(\color{blue}{\mathsf{neg}\left(z\right)}, y, \frac{1}{2} \cdot x\right) \]
      2. lower-neg.f6485.2

        \[\leadsto \mathsf{fma}\left(\color{blue}{-z}, y, 0.5 \cdot x\right) \]
    7. Applied rewrites85.2%

      \[\leadsto \mathsf{fma}\left(\color{blue}{-z}, y, 0.5 \cdot x\right) \]

    if -340 < (+.f64 (-.f64 #s(literal 1 binary64) z) (log.f64 z))

    1. Initial program 99.7%

      \[x \cdot 0.5 + y \cdot \left(\left(1 - z\right) + \log z\right) \]
    2. Add Preprocessing
    3. Taylor expanded in y around inf

      \[\leadsto \color{blue}{y \cdot \left(\left(1 + \log z\right) - z\right)} \]
    4. Step-by-step derivation
      1. sub-negN/A

        \[\leadsto y \cdot \color{blue}{\left(\left(1 + \log z\right) + \left(\mathsf{neg}\left(z\right)\right)\right)} \]
      2. associate-+r+N/A

        \[\leadsto y \cdot \color{blue}{\left(1 + \left(\log z + \left(\mathsf{neg}\left(z\right)\right)\right)\right)} \]
      3. mul-1-negN/A

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

        \[\leadsto y \cdot \color{blue}{\left(\left(\log z + -1 \cdot z\right) + 1\right)} \]
      5. distribute-rgt-inN/A

        \[\leadsto \color{blue}{\left(\log z + -1 \cdot z\right) \cdot y + 1 \cdot y} \]
      6. *-lft-identityN/A

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

        \[\leadsto \color{blue}{\mathsf{fma}\left(\log z + -1 \cdot z, y, y\right)} \]
      8. mul-1-negN/A

        \[\leadsto \mathsf{fma}\left(\log z + \color{blue}{\left(\mathsf{neg}\left(z\right)\right)}, y, y\right) \]
      9. sub-negN/A

        \[\leadsto \mathsf{fma}\left(\color{blue}{\log z - z}, y, y\right) \]
      10. lower--.f64N/A

        \[\leadsto \mathsf{fma}\left(\color{blue}{\log z - z}, y, y\right) \]
      11. lower-log.f6468.7

        \[\leadsto \mathsf{fma}\left(\color{blue}{\log z} - z, y, y\right) \]
    5. Applied rewrites68.7%

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

      \[\leadsto \mathsf{fma}\left(\log z, y, y\right) \]
    7. Step-by-step derivation
      1. Applied rewrites66.0%

        \[\leadsto \mathsf{fma}\left(\log z, y, y\right) \]
    8. Recombined 2 regimes into one program.
    9. Final simplification80.3%

      \[\leadsto \begin{array}{l} \mathbf{if}\;\left(1 - z\right) + \log z \leq -340:\\ \;\;\;\;\mathsf{fma}\left(-z, y, x \cdot 0.5\right)\\ \mathbf{else}:\\ \;\;\;\;\mathsf{fma}\left(\log z, y, y\right)\\ \end{array} \]
    10. Add Preprocessing

    Alternative 5: 85.6% accurate, 1.0× speedup?

    \[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;y \leq -9 \cdot 10^{+22}:\\ \;\;\;\;\left(\left(1 + \log z\right) - z\right) \cdot y\\ \mathbf{elif}\;y \leq 1.9 \cdot 10^{+22}:\\ \;\;\;\;\mathsf{fma}\left(-z, y, x \cdot 0.5\right)\\ \mathbf{else}:\\ \;\;\;\;\mathsf{fma}\left(\log z - z, y, y\right)\\ \end{array} \end{array} \]
    (FPCore (x y z)
     :precision binary64
     (if (<= y -9e+22)
       (* (- (+ 1.0 (log z)) z) y)
       (if (<= y 1.9e+22) (fma (- z) y (* x 0.5)) (fma (- (log z) z) y y))))
    double code(double x, double y, double z) {
    	double tmp;
    	if (y <= -9e+22) {
    		tmp = ((1.0 + log(z)) - z) * y;
    	} else if (y <= 1.9e+22) {
    		tmp = fma(-z, y, (x * 0.5));
    	} else {
    		tmp = fma((log(z) - z), y, y);
    	}
    	return tmp;
    }
    
    function code(x, y, z)
    	tmp = 0.0
    	if (y <= -9e+22)
    		tmp = Float64(Float64(Float64(1.0 + log(z)) - z) * y);
    	elseif (y <= 1.9e+22)
    		tmp = fma(Float64(-z), y, Float64(x * 0.5));
    	else
    		tmp = fma(Float64(log(z) - z), y, y);
    	end
    	return tmp
    end
    
    code[x_, y_, z_] := If[LessEqual[y, -9e+22], N[(N[(N[(1.0 + N[Log[z], $MachinePrecision]), $MachinePrecision] - z), $MachinePrecision] * y), $MachinePrecision], If[LessEqual[y, 1.9e+22], N[((-z) * y + N[(x * 0.5), $MachinePrecision]), $MachinePrecision], N[(N[(N[Log[z], $MachinePrecision] - z), $MachinePrecision] * y + y), $MachinePrecision]]]
    
    \begin{array}{l}
    
    \\
    \begin{array}{l}
    \mathbf{if}\;y \leq -9 \cdot 10^{+22}:\\
    \;\;\;\;\left(\left(1 + \log z\right) - z\right) \cdot y\\
    
    \mathbf{elif}\;y \leq 1.9 \cdot 10^{+22}:\\
    \;\;\;\;\mathsf{fma}\left(-z, y, x \cdot 0.5\right)\\
    
    \mathbf{else}:\\
    \;\;\;\;\mathsf{fma}\left(\log z - z, y, y\right)\\
    
    
    \end{array}
    \end{array}
    
    Derivation
    1. Split input into 3 regimes
    2. if y < -8.9999999999999996e22

      1. Initial program 99.8%

        \[x \cdot 0.5 + y \cdot \left(\left(1 - z\right) + \log z\right) \]
      2. Add Preprocessing
      3. Taylor expanded in y around inf

        \[\leadsto \color{blue}{y \cdot \left(\left(1 + \log z\right) - z\right)} \]
      4. Step-by-step derivation
        1. sub-negN/A

          \[\leadsto y \cdot \color{blue}{\left(\left(1 + \log z\right) + \left(\mathsf{neg}\left(z\right)\right)\right)} \]
        2. associate-+r+N/A

          \[\leadsto y \cdot \color{blue}{\left(1 + \left(\log z + \left(\mathsf{neg}\left(z\right)\right)\right)\right)} \]
        3. mul-1-negN/A

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

          \[\leadsto y \cdot \color{blue}{\left(\left(\log z + -1 \cdot z\right) + 1\right)} \]
        5. distribute-rgt-inN/A

          \[\leadsto \color{blue}{\left(\log z + -1 \cdot z\right) \cdot y + 1 \cdot y} \]
        6. *-lft-identityN/A

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

          \[\leadsto \color{blue}{\mathsf{fma}\left(\log z + -1 \cdot z, y, y\right)} \]
        8. mul-1-negN/A

          \[\leadsto \mathsf{fma}\left(\log z + \color{blue}{\left(\mathsf{neg}\left(z\right)\right)}, y, y\right) \]
        9. sub-negN/A

          \[\leadsto \mathsf{fma}\left(\color{blue}{\log z - z}, y, y\right) \]
        10. lower--.f64N/A

          \[\leadsto \mathsf{fma}\left(\color{blue}{\log z - z}, y, y\right) \]
        11. lower-log.f6486.3

          \[\leadsto \mathsf{fma}\left(\color{blue}{\log z} - z, y, y\right) \]
      5. Applied rewrites86.3%

        \[\leadsto \color{blue}{\mathsf{fma}\left(\log z - z, y, y\right)} \]
      6. Step-by-step derivation
        1. Applied rewrites86.3%

          \[\leadsto \left(\left(1 + \log z\right) - z\right) \cdot \color{blue}{y} \]

        if -8.9999999999999996e22 < y < 1.9000000000000002e22

        1. Initial program 99.9%

          \[x \cdot 0.5 + y \cdot \left(\left(1 - z\right) + \log z\right) \]
        2. Add Preprocessing
        3. Step-by-step derivation
          1. lift-+.f64N/A

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

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

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

            \[\leadsto \color{blue}{\left(\left(1 - z\right) + \log z\right) \cdot y} + x \cdot \frac{1}{2} \]
          5. lower-fma.f64100.0

            \[\leadsto \color{blue}{\mathsf{fma}\left(\left(1 - z\right) + \log z, y, x \cdot 0.5\right)} \]
          6. lift-+.f64N/A

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

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

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

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

            \[\leadsto \mathsf{fma}\left(\color{blue}{\left(\log z + 1\right) - z}, y, x \cdot \frac{1}{2}\right) \]
          11. lower-+.f64100.0

            \[\leadsto \mathsf{fma}\left(\color{blue}{\left(\log z + 1\right)} - z, y, x \cdot 0.5\right) \]
          12. lift-*.f64N/A

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

            \[\leadsto \mathsf{fma}\left(\left(\log z + 1\right) - z, y, \color{blue}{\frac{1}{2} \cdot x}\right) \]
          14. lower-*.f64100.0

            \[\leadsto \mathsf{fma}\left(\left(\log z + 1\right) - z, y, \color{blue}{0.5 \cdot x}\right) \]
        4. Applied rewrites100.0%

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

          \[\leadsto \mathsf{fma}\left(\color{blue}{-1 \cdot z}, y, \frac{1}{2} \cdot x\right) \]
        6. Step-by-step derivation
          1. mul-1-negN/A

            \[\leadsto \mathsf{fma}\left(\color{blue}{\mathsf{neg}\left(z\right)}, y, \frac{1}{2} \cdot x\right) \]
          2. lower-neg.f6489.0

            \[\leadsto \mathsf{fma}\left(\color{blue}{-z}, y, 0.5 \cdot x\right) \]
        7. Applied rewrites89.0%

          \[\leadsto \mathsf{fma}\left(\color{blue}{-z}, y, 0.5 \cdot x\right) \]

        if 1.9000000000000002e22 < y

        1. Initial program 99.8%

          \[x \cdot 0.5 + y \cdot \left(\left(1 - z\right) + \log z\right) \]
        2. Add Preprocessing
        3. Taylor expanded in y around inf

          \[\leadsto \color{blue}{y \cdot \left(\left(1 + \log z\right) - z\right)} \]
        4. Step-by-step derivation
          1. sub-negN/A

            \[\leadsto y \cdot \color{blue}{\left(\left(1 + \log z\right) + \left(\mathsf{neg}\left(z\right)\right)\right)} \]
          2. associate-+r+N/A

            \[\leadsto y \cdot \color{blue}{\left(1 + \left(\log z + \left(\mathsf{neg}\left(z\right)\right)\right)\right)} \]
          3. mul-1-negN/A

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

            \[\leadsto y \cdot \color{blue}{\left(\left(\log z + -1 \cdot z\right) + 1\right)} \]
          5. distribute-rgt-inN/A

            \[\leadsto \color{blue}{\left(\log z + -1 \cdot z\right) \cdot y + 1 \cdot y} \]
          6. *-lft-identityN/A

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

            \[\leadsto \color{blue}{\mathsf{fma}\left(\log z + -1 \cdot z, y, y\right)} \]
          8. mul-1-negN/A

            \[\leadsto \mathsf{fma}\left(\log z + \color{blue}{\left(\mathsf{neg}\left(z\right)\right)}, y, y\right) \]
          9. sub-negN/A

            \[\leadsto \mathsf{fma}\left(\color{blue}{\log z - z}, y, y\right) \]
          10. lower--.f64N/A

            \[\leadsto \mathsf{fma}\left(\color{blue}{\log z - z}, y, y\right) \]
          11. lower-log.f6490.8

            \[\leadsto \mathsf{fma}\left(\color{blue}{\log z} - z, y, y\right) \]
        5. Applied rewrites90.8%

          \[\leadsto \color{blue}{\mathsf{fma}\left(\log z - z, y, y\right)} \]
      7. Recombined 3 regimes into one program.
      8. Final simplification88.8%

        \[\leadsto \begin{array}{l} \mathbf{if}\;y \leq -9 \cdot 10^{+22}:\\ \;\;\;\;\left(\left(1 + \log z\right) - z\right) \cdot y\\ \mathbf{elif}\;y \leq 1.9 \cdot 10^{+22}:\\ \;\;\;\;\mathsf{fma}\left(-z, y, x \cdot 0.5\right)\\ \mathbf{else}:\\ \;\;\;\;\mathsf{fma}\left(\log z - z, y, y\right)\\ \end{array} \]
      9. Add Preprocessing

      Alternative 6: 85.6% accurate, 1.0× speedup?

      \[\begin{array}{l} \\ \begin{array}{l} t_0 := \mathsf{fma}\left(\log z - z, y, y\right)\\ \mathbf{if}\;y \leq -9 \cdot 10^{+22}:\\ \;\;\;\;t\_0\\ \mathbf{elif}\;y \leq 1.9 \cdot 10^{+22}:\\ \;\;\;\;\mathsf{fma}\left(-z, y, x \cdot 0.5\right)\\ \mathbf{else}:\\ \;\;\;\;t\_0\\ \end{array} \end{array} \]
      (FPCore (x y z)
       :precision binary64
       (let* ((t_0 (fma (- (log z) z) y y)))
         (if (<= y -9e+22) t_0 (if (<= y 1.9e+22) (fma (- z) y (* x 0.5)) t_0))))
      double code(double x, double y, double z) {
      	double t_0 = fma((log(z) - z), y, y);
      	double tmp;
      	if (y <= -9e+22) {
      		tmp = t_0;
      	} else if (y <= 1.9e+22) {
      		tmp = fma(-z, y, (x * 0.5));
      	} else {
      		tmp = t_0;
      	}
      	return tmp;
      }
      
      function code(x, y, z)
      	t_0 = fma(Float64(log(z) - z), y, y)
      	tmp = 0.0
      	if (y <= -9e+22)
      		tmp = t_0;
      	elseif (y <= 1.9e+22)
      		tmp = fma(Float64(-z), y, Float64(x * 0.5));
      	else
      		tmp = t_0;
      	end
      	return tmp
      end
      
      code[x_, y_, z_] := Block[{t$95$0 = N[(N[(N[Log[z], $MachinePrecision] - z), $MachinePrecision] * y + y), $MachinePrecision]}, If[LessEqual[y, -9e+22], t$95$0, If[LessEqual[y, 1.9e+22], N[((-z) * y + N[(x * 0.5), $MachinePrecision]), $MachinePrecision], t$95$0]]]
      
      \begin{array}{l}
      
      \\
      \begin{array}{l}
      t_0 := \mathsf{fma}\left(\log z - z, y, y\right)\\
      \mathbf{if}\;y \leq -9 \cdot 10^{+22}:\\
      \;\;\;\;t\_0\\
      
      \mathbf{elif}\;y \leq 1.9 \cdot 10^{+22}:\\
      \;\;\;\;\mathsf{fma}\left(-z, y, x \cdot 0.5\right)\\
      
      \mathbf{else}:\\
      \;\;\;\;t\_0\\
      
      
      \end{array}
      \end{array}
      
      Derivation
      1. Split input into 2 regimes
      2. if y < -8.9999999999999996e22 or 1.9000000000000002e22 < y

        1. Initial program 99.8%

          \[x \cdot 0.5 + y \cdot \left(\left(1 - z\right) + \log z\right) \]
        2. Add Preprocessing
        3. Taylor expanded in y around inf

          \[\leadsto \color{blue}{y \cdot \left(\left(1 + \log z\right) - z\right)} \]
        4. Step-by-step derivation
          1. sub-negN/A

            \[\leadsto y \cdot \color{blue}{\left(\left(1 + \log z\right) + \left(\mathsf{neg}\left(z\right)\right)\right)} \]
          2. associate-+r+N/A

            \[\leadsto y \cdot \color{blue}{\left(1 + \left(\log z + \left(\mathsf{neg}\left(z\right)\right)\right)\right)} \]
          3. mul-1-negN/A

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

            \[\leadsto y \cdot \color{blue}{\left(\left(\log z + -1 \cdot z\right) + 1\right)} \]
          5. distribute-rgt-inN/A

            \[\leadsto \color{blue}{\left(\log z + -1 \cdot z\right) \cdot y + 1 \cdot y} \]
          6. *-lft-identityN/A

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

            \[\leadsto \color{blue}{\mathsf{fma}\left(\log z + -1 \cdot z, y, y\right)} \]
          8. mul-1-negN/A

            \[\leadsto \mathsf{fma}\left(\log z + \color{blue}{\left(\mathsf{neg}\left(z\right)\right)}, y, y\right) \]
          9. sub-negN/A

            \[\leadsto \mathsf{fma}\left(\color{blue}{\log z - z}, y, y\right) \]
          10. lower--.f64N/A

            \[\leadsto \mathsf{fma}\left(\color{blue}{\log z - z}, y, y\right) \]
          11. lower-log.f6488.6

            \[\leadsto \mathsf{fma}\left(\color{blue}{\log z} - z, y, y\right) \]
        5. Applied rewrites88.6%

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

        if -8.9999999999999996e22 < y < 1.9000000000000002e22

        1. Initial program 99.9%

          \[x \cdot 0.5 + y \cdot \left(\left(1 - z\right) + \log z\right) \]
        2. Add Preprocessing
        3. Step-by-step derivation
          1. lift-+.f64N/A

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

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

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

            \[\leadsto \color{blue}{\left(\left(1 - z\right) + \log z\right) \cdot y} + x \cdot \frac{1}{2} \]
          5. lower-fma.f64100.0

            \[\leadsto \color{blue}{\mathsf{fma}\left(\left(1 - z\right) + \log z, y, x \cdot 0.5\right)} \]
          6. lift-+.f64N/A

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

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

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

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

            \[\leadsto \mathsf{fma}\left(\color{blue}{\left(\log z + 1\right) - z}, y, x \cdot \frac{1}{2}\right) \]
          11. lower-+.f64100.0

            \[\leadsto \mathsf{fma}\left(\color{blue}{\left(\log z + 1\right)} - z, y, x \cdot 0.5\right) \]
          12. lift-*.f64N/A

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

            \[\leadsto \mathsf{fma}\left(\left(\log z + 1\right) - z, y, \color{blue}{\frac{1}{2} \cdot x}\right) \]
          14. lower-*.f64100.0

            \[\leadsto \mathsf{fma}\left(\left(\log z + 1\right) - z, y, \color{blue}{0.5 \cdot x}\right) \]
        4. Applied rewrites100.0%

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

          \[\leadsto \mathsf{fma}\left(\color{blue}{-1 \cdot z}, y, \frac{1}{2} \cdot x\right) \]
        6. Step-by-step derivation
          1. mul-1-negN/A

            \[\leadsto \mathsf{fma}\left(\color{blue}{\mathsf{neg}\left(z\right)}, y, \frac{1}{2} \cdot x\right) \]
          2. lower-neg.f6489.0

            \[\leadsto \mathsf{fma}\left(\color{blue}{-z}, y, 0.5 \cdot x\right) \]
        7. Applied rewrites89.0%

          \[\leadsto \mathsf{fma}\left(\color{blue}{-z}, y, 0.5 \cdot x\right) \]
      3. Recombined 2 regimes into one program.
      4. Final simplification88.8%

        \[\leadsto \begin{array}{l} \mathbf{if}\;y \leq -9 \cdot 10^{+22}:\\ \;\;\;\;\mathsf{fma}\left(\log z - z, y, y\right)\\ \mathbf{elif}\;y \leq 1.9 \cdot 10^{+22}:\\ \;\;\;\;\mathsf{fma}\left(-z, y, x \cdot 0.5\right)\\ \mathbf{else}:\\ \;\;\;\;\mathsf{fma}\left(\log z - z, y, y\right)\\ \end{array} \]
      5. Add Preprocessing

      Alternative 7: 74.3% accurate, 8.6× speedup?

      \[\begin{array}{l} \\ \mathsf{fma}\left(-z, y, x \cdot 0.5\right) \end{array} \]
      (FPCore (x y z) :precision binary64 (fma (- z) y (* x 0.5)))
      double code(double x, double y, double z) {
      	return fma(-z, y, (x * 0.5));
      }
      
      function code(x, y, z)
      	return fma(Float64(-z), y, Float64(x * 0.5))
      end
      
      code[x_, y_, z_] := N[((-z) * y + N[(x * 0.5), $MachinePrecision]), $MachinePrecision]
      
      \begin{array}{l}
      
      \\
      \mathsf{fma}\left(-z, y, x \cdot 0.5\right)
      \end{array}
      
      Derivation
      1. Initial program 99.9%

        \[x \cdot 0.5 + y \cdot \left(\left(1 - z\right) + \log z\right) \]
      2. Add Preprocessing
      3. Step-by-step derivation
        1. lift-+.f64N/A

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

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

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

          \[\leadsto \color{blue}{\left(\left(1 - z\right) + \log z\right) \cdot y} + x \cdot \frac{1}{2} \]
        5. lower-fma.f6499.9

          \[\leadsto \color{blue}{\mathsf{fma}\left(\left(1 - z\right) + \log z, y, x \cdot 0.5\right)} \]
        6. lift-+.f64N/A

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

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

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

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

          \[\leadsto \mathsf{fma}\left(\color{blue}{\left(\log z + 1\right) - z}, y, x \cdot \frac{1}{2}\right) \]
        11. lower-+.f6499.9

          \[\leadsto \mathsf{fma}\left(\color{blue}{\left(\log z + 1\right)} - z, y, x \cdot 0.5\right) \]
        12. lift-*.f64N/A

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

          \[\leadsto \mathsf{fma}\left(\left(\log z + 1\right) - z, y, \color{blue}{\frac{1}{2} \cdot x}\right) \]
        14. lower-*.f6499.9

          \[\leadsto \mathsf{fma}\left(\left(\log z + 1\right) - z, y, \color{blue}{0.5 \cdot x}\right) \]
      4. Applied rewrites99.9%

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

        \[\leadsto \mathsf{fma}\left(\color{blue}{-1 \cdot z}, y, \frac{1}{2} \cdot x\right) \]
      6. Step-by-step derivation
        1. mul-1-negN/A

          \[\leadsto \mathsf{fma}\left(\color{blue}{\mathsf{neg}\left(z\right)}, y, \frac{1}{2} \cdot x\right) \]
        2. lower-neg.f6472.6

          \[\leadsto \mathsf{fma}\left(\color{blue}{-z}, y, 0.5 \cdot x\right) \]
      7. Applied rewrites72.6%

        \[\leadsto \mathsf{fma}\left(\color{blue}{-z}, y, 0.5 \cdot x\right) \]
      8. Final simplification72.6%

        \[\leadsto \mathsf{fma}\left(-z, y, x \cdot 0.5\right) \]
      9. Add Preprocessing

      Alternative 8: 39.3% accurate, 20.0× speedup?

      \[\begin{array}{l} \\ x \cdot 0.5 \end{array} \]
      (FPCore (x y z) :precision binary64 (* x 0.5))
      double code(double x, double y, double z) {
      	return x * 0.5;
      }
      
      real(8) function code(x, y, z)
          real(8), intent (in) :: x
          real(8), intent (in) :: y
          real(8), intent (in) :: z
          code = x * 0.5d0
      end function
      
      public static double code(double x, double y, double z) {
      	return x * 0.5;
      }
      
      def code(x, y, z):
      	return x * 0.5
      
      function code(x, y, z)
      	return Float64(x * 0.5)
      end
      
      function tmp = code(x, y, z)
      	tmp = x * 0.5;
      end
      
      code[x_, y_, z_] := N[(x * 0.5), $MachinePrecision]
      
      \begin{array}{l}
      
      \\
      x \cdot 0.5
      \end{array}
      
      Derivation
      1. Initial program 99.9%

        \[x \cdot 0.5 + y \cdot \left(\left(1 - z\right) + \log z\right) \]
      2. Add Preprocessing
      3. Taylor expanded in y around 0

        \[\leadsto \color{blue}{\frac{1}{2} \cdot x} \]
      4. Step-by-step derivation
        1. *-commutativeN/A

          \[\leadsto \color{blue}{x \cdot \frac{1}{2}} \]
        2. lower-*.f6437.6

          \[\leadsto \color{blue}{x \cdot 0.5} \]
      5. Applied rewrites37.6%

        \[\leadsto \color{blue}{x \cdot 0.5} \]
      6. Add Preprocessing

      Developer Target 1: 99.8% accurate, 1.0× speedup?

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

      Reproduce

      ?
      herbie shell --seed 2024235 
      (FPCore (x y z)
        :name "System.Random.MWC.Distributions:gamma from mwc-random-0.13.3.2"
        :precision binary64
      
        :alt
        (! :herbie-platform default (- (+ y (* 1/2 x)) (* y (- z (log z)))))
      
        (+ (* x 0.5) (* y (+ (- 1.0 z) (log z)))))