Diagrams.Solve.Tridiagonal:solveTriDiagonal from diagrams-solve-0.1, B

Percentage Accurate: 95.8% → 99.7%
Time: 9.7s
Alternatives: 7
Speedup: 0.3×

Specification

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

\\
\frac{x}{y - z \cdot 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 7 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: 95.8% accurate, 1.0× speedup?

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

\\
\frac{x}{y - z \cdot t}
\end{array}

Alternative 1: 99.7% accurate, 0.1× speedup?

\[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;z \cdot t \leq -\infty \lor \neg \left(z \cdot t \leq 5 \cdot 10^{+226}\right):\\ \;\;\;\;\frac{\frac{x}{-t}}{z}\\ \mathbf{else}:\\ \;\;\;\;\frac{x}{\mathsf{fma}\left(z, -t, y\right)}\\ \end{array} \end{array} \]
(FPCore (x y z t)
 :precision binary64
 (if (or (<= (* z t) (- INFINITY)) (not (<= (* z t) 5e+226)))
   (/ (/ x (- t)) z)
   (/ x (fma z (- t) y))))
double code(double x, double y, double z, double t) {
	double tmp;
	if (((z * t) <= -((double) INFINITY)) || !((z * t) <= 5e+226)) {
		tmp = (x / -t) / z;
	} else {
		tmp = x / fma(z, -t, y);
	}
	return tmp;
}
function code(x, y, z, t)
	tmp = 0.0
	if ((Float64(z * t) <= Float64(-Inf)) || !(Float64(z * t) <= 5e+226))
		tmp = Float64(Float64(x / Float64(-t)) / z);
	else
		tmp = Float64(x / fma(z, Float64(-t), y));
	end
	return tmp
end
code[x_, y_, z_, t_] := If[Or[LessEqual[N[(z * t), $MachinePrecision], (-Infinity)], N[Not[LessEqual[N[(z * t), $MachinePrecision], 5e+226]], $MachinePrecision]], N[(N[(x / (-t)), $MachinePrecision] / z), $MachinePrecision], N[(x / N[(z * (-t) + y), $MachinePrecision]), $MachinePrecision]]
\begin{array}{l}

\\
\begin{array}{l}
\mathbf{if}\;z \cdot t \leq -\infty \lor \neg \left(z \cdot t \leq 5 \cdot 10^{+226}\right):\\
\;\;\;\;\frac{\frac{x}{-t}}{z}\\

\mathbf{else}:\\
\;\;\;\;\frac{x}{\mathsf{fma}\left(z, -t, y\right)}\\


\end{array}
\end{array}
Derivation
  1. Split input into 2 regimes
  2. if (*.f64 z t) < -inf.0 or 5.0000000000000005e226 < (*.f64 z t)

    1. Initial program 63.6%

      \[\frac{x}{y - z \cdot t} \]
    2. Add Preprocessing
    3. Taylor expanded in z around inf 89.7%

      \[\leadsto \color{blue}{\frac{-1 \cdot \frac{x}{t} + -1 \cdot \frac{x \cdot y}{{t}^{2} \cdot z}}{z}} \]
    4. Step-by-step derivation
      1. distribute-lft-out89.7%

        \[\leadsto \frac{\color{blue}{-1 \cdot \left(\frac{x}{t} + \frac{x \cdot y}{{t}^{2} \cdot z}\right)}}{z} \]
      2. associate-*r/89.7%

        \[\leadsto \color{blue}{-1 \cdot \frac{\frac{x}{t} + \frac{x \cdot y}{{t}^{2} \cdot z}}{z}} \]
      3. mul-1-neg89.7%

        \[\leadsto \color{blue}{-\frac{\frac{x}{t} + \frac{x \cdot y}{{t}^{2} \cdot z}}{z}} \]
      4. *-commutative89.7%

        \[\leadsto -\frac{\frac{x}{t} + \frac{x \cdot y}{\color{blue}{z \cdot {t}^{2}}}}{z} \]
    5. Simplified89.7%

      \[\leadsto \color{blue}{-\frac{\frac{x}{t} + \frac{x \cdot y}{z \cdot {t}^{2}}}{z}} \]
    6. Taylor expanded in t around inf 99.9%

      \[\leadsto -\frac{\color{blue}{\frac{x}{t}}}{z} \]

    if -inf.0 < (*.f64 z t) < 5.0000000000000005e226

    1. Initial program 99.8%

      \[\frac{x}{y - z \cdot t} \]
    2. Step-by-step derivation
      1. cancel-sign-sub-inv99.8%

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

        \[\leadsto \frac{x}{\color{blue}{\left(-z\right) \cdot t + y}} \]
      3. distribute-lft-neg-out99.8%

        \[\leadsto \frac{x}{\color{blue}{\left(-z \cdot t\right)} + y} \]
      4. distribute-rgt-neg-out99.8%

        \[\leadsto \frac{x}{\color{blue}{z \cdot \left(-t\right)} + y} \]
      5. fma-define99.8%

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

      \[\leadsto \color{blue}{\frac{x}{\mathsf{fma}\left(z, -t, y\right)}} \]
    4. Add Preprocessing
  3. Recombined 2 regimes into one program.
  4. Final simplification99.8%

    \[\leadsto \begin{array}{l} \mathbf{if}\;z \cdot t \leq -\infty \lor \neg \left(z \cdot t \leq 5 \cdot 10^{+226}\right):\\ \;\;\;\;\frac{\frac{x}{-t}}{z}\\ \mathbf{else}:\\ \;\;\;\;\frac{x}{\mathsf{fma}\left(z, -t, y\right)}\\ \end{array} \]
  5. Add Preprocessing

Alternative 2: 99.7% accurate, 0.3× speedup?

\[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;z \cdot t \leq -\infty \lor \neg \left(z \cdot t \leq 5 \cdot 10^{+226}\right):\\ \;\;\;\;\frac{\frac{x}{-t}}{z}\\ \mathbf{else}:\\ \;\;\;\;\frac{x}{y - z \cdot t}\\ \end{array} \end{array} \]
(FPCore (x y z t)
 :precision binary64
 (if (or (<= (* z t) (- INFINITY)) (not (<= (* z t) 5e+226)))
   (/ (/ x (- t)) z)
   (/ x (- y (* z t)))))
double code(double x, double y, double z, double t) {
	double tmp;
	if (((z * t) <= -((double) INFINITY)) || !((z * t) <= 5e+226)) {
		tmp = (x / -t) / z;
	} else {
		tmp = x / (y - (z * t));
	}
	return tmp;
}
public static double code(double x, double y, double z, double t) {
	double tmp;
	if (((z * t) <= -Double.POSITIVE_INFINITY) || !((z * t) <= 5e+226)) {
		tmp = (x / -t) / z;
	} else {
		tmp = x / (y - (z * t));
	}
	return tmp;
}
def code(x, y, z, t):
	tmp = 0
	if ((z * t) <= -math.inf) or not ((z * t) <= 5e+226):
		tmp = (x / -t) / z
	else:
		tmp = x / (y - (z * t))
	return tmp
function code(x, y, z, t)
	tmp = 0.0
	if ((Float64(z * t) <= Float64(-Inf)) || !(Float64(z * t) <= 5e+226))
		tmp = Float64(Float64(x / Float64(-t)) / z);
	else
		tmp = Float64(x / Float64(y - Float64(z * t)));
	end
	return tmp
end
function tmp_2 = code(x, y, z, t)
	tmp = 0.0;
	if (((z * t) <= -Inf) || ~(((z * t) <= 5e+226)))
		tmp = (x / -t) / z;
	else
		tmp = x / (y - (z * t));
	end
	tmp_2 = tmp;
end
code[x_, y_, z_, t_] := If[Or[LessEqual[N[(z * t), $MachinePrecision], (-Infinity)], N[Not[LessEqual[N[(z * t), $MachinePrecision], 5e+226]], $MachinePrecision]], N[(N[(x / (-t)), $MachinePrecision] / z), $MachinePrecision], N[(x / N[(y - N[(z * t), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]]
\begin{array}{l}

\\
\begin{array}{l}
\mathbf{if}\;z \cdot t \leq -\infty \lor \neg \left(z \cdot t \leq 5 \cdot 10^{+226}\right):\\
\;\;\;\;\frac{\frac{x}{-t}}{z}\\

\mathbf{else}:\\
\;\;\;\;\frac{x}{y - z \cdot t}\\


\end{array}
\end{array}
Derivation
  1. Split input into 2 regimes
  2. if (*.f64 z t) < -inf.0 or 5.0000000000000005e226 < (*.f64 z t)

    1. Initial program 63.6%

      \[\frac{x}{y - z \cdot t} \]
    2. Add Preprocessing
    3. Taylor expanded in z around inf 89.7%

      \[\leadsto \color{blue}{\frac{-1 \cdot \frac{x}{t} + -1 \cdot \frac{x \cdot y}{{t}^{2} \cdot z}}{z}} \]
    4. Step-by-step derivation
      1. distribute-lft-out89.7%

        \[\leadsto \frac{\color{blue}{-1 \cdot \left(\frac{x}{t} + \frac{x \cdot y}{{t}^{2} \cdot z}\right)}}{z} \]
      2. associate-*r/89.7%

        \[\leadsto \color{blue}{-1 \cdot \frac{\frac{x}{t} + \frac{x \cdot y}{{t}^{2} \cdot z}}{z}} \]
      3. mul-1-neg89.7%

        \[\leadsto \color{blue}{-\frac{\frac{x}{t} + \frac{x \cdot y}{{t}^{2} \cdot z}}{z}} \]
      4. *-commutative89.7%

        \[\leadsto -\frac{\frac{x}{t} + \frac{x \cdot y}{\color{blue}{z \cdot {t}^{2}}}}{z} \]
    5. Simplified89.7%

      \[\leadsto \color{blue}{-\frac{\frac{x}{t} + \frac{x \cdot y}{z \cdot {t}^{2}}}{z}} \]
    6. Taylor expanded in t around inf 99.9%

      \[\leadsto -\frac{\color{blue}{\frac{x}{t}}}{z} \]

    if -inf.0 < (*.f64 z t) < 5.0000000000000005e226

    1. Initial program 99.8%

      \[\frac{x}{y - z \cdot t} \]
    2. Add Preprocessing
  3. Recombined 2 regimes into one program.
  4. Final simplification99.8%

    \[\leadsto \begin{array}{l} \mathbf{if}\;z \cdot t \leq -\infty \lor \neg \left(z \cdot t \leq 5 \cdot 10^{+226}\right):\\ \;\;\;\;\frac{\frac{x}{-t}}{z}\\ \mathbf{else}:\\ \;\;\;\;\frac{x}{y - z \cdot t}\\ \end{array} \]
  5. Add Preprocessing

Alternative 3: 78.6% accurate, 0.3× speedup?

\[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;z \cdot t \leq -1 \cdot 10^{+45} \lor \neg \left(z \cdot t \leq 2 \cdot 10^{-91}\right):\\ \;\;\;\;\frac{\frac{x}{-t}}{z}\\ \mathbf{else}:\\ \;\;\;\;\frac{x}{y}\\ \end{array} \end{array} \]
(FPCore (x y z t)
 :precision binary64
 (if (or (<= (* z t) -1e+45) (not (<= (* z t) 2e-91)))
   (/ (/ x (- t)) z)
   (/ x y)))
double code(double x, double y, double z, double t) {
	double tmp;
	if (((z * t) <= -1e+45) || !((z * t) <= 2e-91)) {
		tmp = (x / -t) / z;
	} else {
		tmp = x / y;
	}
	return tmp;
}
real(8) function code(x, y, z, t)
    real(8), intent (in) :: x
    real(8), intent (in) :: y
    real(8), intent (in) :: z
    real(8), intent (in) :: t
    real(8) :: tmp
    if (((z * t) <= (-1d+45)) .or. (.not. ((z * t) <= 2d-91))) then
        tmp = (x / -t) / z
    else
        tmp = x / y
    end if
    code = tmp
end function
public static double code(double x, double y, double z, double t) {
	double tmp;
	if (((z * t) <= -1e+45) || !((z * t) <= 2e-91)) {
		tmp = (x / -t) / z;
	} else {
		tmp = x / y;
	}
	return tmp;
}
def code(x, y, z, t):
	tmp = 0
	if ((z * t) <= -1e+45) or not ((z * t) <= 2e-91):
		tmp = (x / -t) / z
	else:
		tmp = x / y
	return tmp
function code(x, y, z, t)
	tmp = 0.0
	if ((Float64(z * t) <= -1e+45) || !(Float64(z * t) <= 2e-91))
		tmp = Float64(Float64(x / Float64(-t)) / z);
	else
		tmp = Float64(x / y);
	end
	return tmp
end
function tmp_2 = code(x, y, z, t)
	tmp = 0.0;
	if (((z * t) <= -1e+45) || ~(((z * t) <= 2e-91)))
		tmp = (x / -t) / z;
	else
		tmp = x / y;
	end
	tmp_2 = tmp;
end
code[x_, y_, z_, t_] := If[Or[LessEqual[N[(z * t), $MachinePrecision], -1e+45], N[Not[LessEqual[N[(z * t), $MachinePrecision], 2e-91]], $MachinePrecision]], N[(N[(x / (-t)), $MachinePrecision] / z), $MachinePrecision], N[(x / y), $MachinePrecision]]
\begin{array}{l}

\\
\begin{array}{l}
\mathbf{if}\;z \cdot t \leq -1 \cdot 10^{+45} \lor \neg \left(z \cdot t \leq 2 \cdot 10^{-91}\right):\\
\;\;\;\;\frac{\frac{x}{-t}}{z}\\

\mathbf{else}:\\
\;\;\;\;\frac{x}{y}\\


\end{array}
\end{array}
Derivation
  1. Split input into 2 regimes
  2. if (*.f64 z t) < -9.9999999999999993e44 or 2.00000000000000004e-91 < (*.f64 z t)

    1. Initial program 88.7%

      \[\frac{x}{y - z \cdot t} \]
    2. Add Preprocessing
    3. Taylor expanded in z around inf 70.3%

      \[\leadsto \color{blue}{\frac{-1 \cdot \frac{x}{t} + -1 \cdot \frac{x \cdot y}{{t}^{2} \cdot z}}{z}} \]
    4. Step-by-step derivation
      1. distribute-lft-out70.3%

        \[\leadsto \frac{\color{blue}{-1 \cdot \left(\frac{x}{t} + \frac{x \cdot y}{{t}^{2} \cdot z}\right)}}{z} \]
      2. associate-*r/70.3%

        \[\leadsto \color{blue}{-1 \cdot \frac{\frac{x}{t} + \frac{x \cdot y}{{t}^{2} \cdot z}}{z}} \]
      3. mul-1-neg70.3%

        \[\leadsto \color{blue}{-\frac{\frac{x}{t} + \frac{x \cdot y}{{t}^{2} \cdot z}}{z}} \]
      4. *-commutative70.3%

        \[\leadsto -\frac{\frac{x}{t} + \frac{x \cdot y}{\color{blue}{z \cdot {t}^{2}}}}{z} \]
    5. Simplified70.3%

      \[\leadsto \color{blue}{-\frac{\frac{x}{t} + \frac{x \cdot y}{z \cdot {t}^{2}}}{z}} \]
    6. Taylor expanded in t around inf 77.2%

      \[\leadsto -\frac{\color{blue}{\frac{x}{t}}}{z} \]

    if -9.9999999999999993e44 < (*.f64 z t) < 2.00000000000000004e-91

    1. Initial program 99.9%

      \[\frac{x}{y - z \cdot t} \]
    2. Add Preprocessing
    3. Taylor expanded in y around inf 86.2%

      \[\leadsto \color{blue}{\frac{x}{y}} \]
  3. Recombined 2 regimes into one program.
  4. Final simplification81.7%

    \[\leadsto \begin{array}{l} \mathbf{if}\;z \cdot t \leq -1 \cdot 10^{+45} \lor \neg \left(z \cdot t \leq 2 \cdot 10^{-91}\right):\\ \;\;\;\;\frac{\frac{x}{-t}}{z}\\ \mathbf{else}:\\ \;\;\;\;\frac{x}{y}\\ \end{array} \]
  5. Add Preprocessing

Alternative 4: 78.8% accurate, 0.3× speedup?

\[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;z \cdot t \leq -1 \cdot 10^{+57}:\\ \;\;\;\;\frac{-1}{t \cdot \frac{z}{x}}\\ \mathbf{elif}\;z \cdot t \leq 2 \cdot 10^{-91}:\\ \;\;\;\;\frac{x}{y}\\ \mathbf{else}:\\ \;\;\;\;\frac{\frac{x}{-t}}{z}\\ \end{array} \end{array} \]
(FPCore (x y z t)
 :precision binary64
 (if (<= (* z t) -1e+57)
   (/ -1.0 (* t (/ z x)))
   (if (<= (* z t) 2e-91) (/ x y) (/ (/ x (- t)) z))))
double code(double x, double y, double z, double t) {
	double tmp;
	if ((z * t) <= -1e+57) {
		tmp = -1.0 / (t * (z / x));
	} else if ((z * t) <= 2e-91) {
		tmp = x / y;
	} else {
		tmp = (x / -t) / z;
	}
	return tmp;
}
real(8) function code(x, y, z, t)
    real(8), intent (in) :: x
    real(8), intent (in) :: y
    real(8), intent (in) :: z
    real(8), intent (in) :: t
    real(8) :: tmp
    if ((z * t) <= (-1d+57)) then
        tmp = (-1.0d0) / (t * (z / x))
    else if ((z * t) <= 2d-91) then
        tmp = x / y
    else
        tmp = (x / -t) / z
    end if
    code = tmp
end function
public static double code(double x, double y, double z, double t) {
	double tmp;
	if ((z * t) <= -1e+57) {
		tmp = -1.0 / (t * (z / x));
	} else if ((z * t) <= 2e-91) {
		tmp = x / y;
	} else {
		tmp = (x / -t) / z;
	}
	return tmp;
}
def code(x, y, z, t):
	tmp = 0
	if (z * t) <= -1e+57:
		tmp = -1.0 / (t * (z / x))
	elif (z * t) <= 2e-91:
		tmp = x / y
	else:
		tmp = (x / -t) / z
	return tmp
function code(x, y, z, t)
	tmp = 0.0
	if (Float64(z * t) <= -1e+57)
		tmp = Float64(-1.0 / Float64(t * Float64(z / x)));
	elseif (Float64(z * t) <= 2e-91)
		tmp = Float64(x / y);
	else
		tmp = Float64(Float64(x / Float64(-t)) / z);
	end
	return tmp
end
function tmp_2 = code(x, y, z, t)
	tmp = 0.0;
	if ((z * t) <= -1e+57)
		tmp = -1.0 / (t * (z / x));
	elseif ((z * t) <= 2e-91)
		tmp = x / y;
	else
		tmp = (x / -t) / z;
	end
	tmp_2 = tmp;
end
code[x_, y_, z_, t_] := If[LessEqual[N[(z * t), $MachinePrecision], -1e+57], N[(-1.0 / N[(t * N[(z / x), $MachinePrecision]), $MachinePrecision]), $MachinePrecision], If[LessEqual[N[(z * t), $MachinePrecision], 2e-91], N[(x / y), $MachinePrecision], N[(N[(x / (-t)), $MachinePrecision] / z), $MachinePrecision]]]
\begin{array}{l}

\\
\begin{array}{l}
\mathbf{if}\;z \cdot t \leq -1 \cdot 10^{+57}:\\
\;\;\;\;\frac{-1}{t \cdot \frac{z}{x}}\\

\mathbf{elif}\;z \cdot t \leq 2 \cdot 10^{-91}:\\
\;\;\;\;\frac{x}{y}\\

\mathbf{else}:\\
\;\;\;\;\frac{\frac{x}{-t}}{z}\\


\end{array}
\end{array}
Derivation
  1. Split input into 3 regimes
  2. if (*.f64 z t) < -1.00000000000000005e57

    1. Initial program 85.7%

      \[\frac{x}{y - z \cdot t} \]
    2. Add Preprocessing
    3. Taylor expanded in z around inf 76.9%

      \[\leadsto \color{blue}{\frac{-1 \cdot \frac{x}{t} + -1 \cdot \frac{x \cdot y}{{t}^{2} \cdot z}}{z}} \]
    4. Step-by-step derivation
      1. distribute-lft-out76.9%

        \[\leadsto \frac{\color{blue}{-1 \cdot \left(\frac{x}{t} + \frac{x \cdot y}{{t}^{2} \cdot z}\right)}}{z} \]
      2. associate-*r/76.9%

        \[\leadsto \color{blue}{-1 \cdot \frac{\frac{x}{t} + \frac{x \cdot y}{{t}^{2} \cdot z}}{z}} \]
      3. mul-1-neg76.9%

        \[\leadsto \color{blue}{-\frac{\frac{x}{t} + \frac{x \cdot y}{{t}^{2} \cdot z}}{z}} \]
      4. *-commutative76.9%

        \[\leadsto -\frac{\frac{x}{t} + \frac{x \cdot y}{\color{blue}{z \cdot {t}^{2}}}}{z} \]
    5. Simplified76.9%

      \[\leadsto \color{blue}{-\frac{\frac{x}{t} + \frac{x \cdot y}{z \cdot {t}^{2}}}{z}} \]
    6. Taylor expanded in t around inf 83.9%

      \[\leadsto -\frac{\color{blue}{\frac{x}{t}}}{z} \]
    7. Step-by-step derivation
      1. neg-mul-183.9%

        \[\leadsto \color{blue}{-1 \cdot \frac{\frac{x}{t}}{z}} \]
      2. clear-num84.6%

        \[\leadsto -1 \cdot \color{blue}{\frac{1}{\frac{z}{\frac{x}{t}}}} \]
      3. un-div-inv84.6%

        \[\leadsto \color{blue}{\frac{-1}{\frac{z}{\frac{x}{t}}}} \]
      4. clear-num84.6%

        \[\leadsto \frac{-1}{\color{blue}{\frac{1}{\frac{\frac{x}{t}}{z}}}} \]
      5. associate-/l/70.5%

        \[\leadsto \frac{-1}{\frac{1}{\color{blue}{\frac{x}{z \cdot t}}}} \]
      6. clear-num70.4%

        \[\leadsto \frac{-1}{\color{blue}{\frac{z \cdot t}{x}}} \]
      7. *-commutative70.4%

        \[\leadsto \frac{-1}{\frac{\color{blue}{t \cdot z}}{x}} \]
      8. associate-/l*84.5%

        \[\leadsto \frac{-1}{\color{blue}{t \cdot \frac{z}{x}}} \]
    8. Applied egg-rr84.5%

      \[\leadsto \color{blue}{\frac{-1}{t \cdot \frac{z}{x}}} \]

    if -1.00000000000000005e57 < (*.f64 z t) < 2.00000000000000004e-91

    1. Initial program 99.9%

      \[\frac{x}{y - z \cdot t} \]
    2. Add Preprocessing
    3. Taylor expanded in y around inf 85.6%

      \[\leadsto \color{blue}{\frac{x}{y}} \]

    if 2.00000000000000004e-91 < (*.f64 z t)

    1. Initial program 90.7%

      \[\frac{x}{y - z \cdot t} \]
    2. Add Preprocessing
    3. Taylor expanded in z around inf 65.2%

      \[\leadsto \color{blue}{\frac{-1 \cdot \frac{x}{t} + -1 \cdot \frac{x \cdot y}{{t}^{2} \cdot z}}{z}} \]
    4. Step-by-step derivation
      1. distribute-lft-out65.2%

        \[\leadsto \frac{\color{blue}{-1 \cdot \left(\frac{x}{t} + \frac{x \cdot y}{{t}^{2} \cdot z}\right)}}{z} \]
      2. associate-*r/65.2%

        \[\leadsto \color{blue}{-1 \cdot \frac{\frac{x}{t} + \frac{x \cdot y}{{t}^{2} \cdot z}}{z}} \]
      3. mul-1-neg65.2%

        \[\leadsto \color{blue}{-\frac{\frac{x}{t} + \frac{x \cdot y}{{t}^{2} \cdot z}}{z}} \]
      4. *-commutative65.2%

        \[\leadsto -\frac{\frac{x}{t} + \frac{x \cdot y}{\color{blue}{z \cdot {t}^{2}}}}{z} \]
    5. Simplified65.2%

      \[\leadsto \color{blue}{-\frac{\frac{x}{t} + \frac{x \cdot y}{z \cdot {t}^{2}}}{z}} \]
    6. Taylor expanded in t around inf 72.2%

      \[\leadsto -\frac{\color{blue}{\frac{x}{t}}}{z} \]
  3. Recombined 3 regimes into one program.
  4. Final simplification81.5%

    \[\leadsto \begin{array}{l} \mathbf{if}\;z \cdot t \leq -1 \cdot 10^{+57}:\\ \;\;\;\;\frac{-1}{t \cdot \frac{z}{x}}\\ \mathbf{elif}\;z \cdot t \leq 2 \cdot 10^{-91}:\\ \;\;\;\;\frac{x}{y}\\ \mathbf{else}:\\ \;\;\;\;\frac{\frac{x}{-t}}{z}\\ \end{array} \]
  5. Add Preprocessing

Alternative 5: 78.9% accurate, 0.3× speedup?

\[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;z \cdot t \leq -1 \cdot 10^{+57}:\\ \;\;\;\;\frac{\frac{x}{z}}{-t}\\ \mathbf{elif}\;z \cdot t \leq 2 \cdot 10^{-91}:\\ \;\;\;\;\frac{x}{y}\\ \mathbf{else}:\\ \;\;\;\;\frac{\frac{x}{-t}}{z}\\ \end{array} \end{array} \]
(FPCore (x y z t)
 :precision binary64
 (if (<= (* z t) -1e+57)
   (/ (/ x z) (- t))
   (if (<= (* z t) 2e-91) (/ x y) (/ (/ x (- t)) z))))
double code(double x, double y, double z, double t) {
	double tmp;
	if ((z * t) <= -1e+57) {
		tmp = (x / z) / -t;
	} else if ((z * t) <= 2e-91) {
		tmp = x / y;
	} else {
		tmp = (x / -t) / z;
	}
	return tmp;
}
real(8) function code(x, y, z, t)
    real(8), intent (in) :: x
    real(8), intent (in) :: y
    real(8), intent (in) :: z
    real(8), intent (in) :: t
    real(8) :: tmp
    if ((z * t) <= (-1d+57)) then
        tmp = (x / z) / -t
    else if ((z * t) <= 2d-91) then
        tmp = x / y
    else
        tmp = (x / -t) / z
    end if
    code = tmp
end function
public static double code(double x, double y, double z, double t) {
	double tmp;
	if ((z * t) <= -1e+57) {
		tmp = (x / z) / -t;
	} else if ((z * t) <= 2e-91) {
		tmp = x / y;
	} else {
		tmp = (x / -t) / z;
	}
	return tmp;
}
def code(x, y, z, t):
	tmp = 0
	if (z * t) <= -1e+57:
		tmp = (x / z) / -t
	elif (z * t) <= 2e-91:
		tmp = x / y
	else:
		tmp = (x / -t) / z
	return tmp
function code(x, y, z, t)
	tmp = 0.0
	if (Float64(z * t) <= -1e+57)
		tmp = Float64(Float64(x / z) / Float64(-t));
	elseif (Float64(z * t) <= 2e-91)
		tmp = Float64(x / y);
	else
		tmp = Float64(Float64(x / Float64(-t)) / z);
	end
	return tmp
end
function tmp_2 = code(x, y, z, t)
	tmp = 0.0;
	if ((z * t) <= -1e+57)
		tmp = (x / z) / -t;
	elseif ((z * t) <= 2e-91)
		tmp = x / y;
	else
		tmp = (x / -t) / z;
	end
	tmp_2 = tmp;
end
code[x_, y_, z_, t_] := If[LessEqual[N[(z * t), $MachinePrecision], -1e+57], N[(N[(x / z), $MachinePrecision] / (-t)), $MachinePrecision], If[LessEqual[N[(z * t), $MachinePrecision], 2e-91], N[(x / y), $MachinePrecision], N[(N[(x / (-t)), $MachinePrecision] / z), $MachinePrecision]]]
\begin{array}{l}

\\
\begin{array}{l}
\mathbf{if}\;z \cdot t \leq -1 \cdot 10^{+57}:\\
\;\;\;\;\frac{\frac{x}{z}}{-t}\\

\mathbf{elif}\;z \cdot t \leq 2 \cdot 10^{-91}:\\
\;\;\;\;\frac{x}{y}\\

\mathbf{else}:\\
\;\;\;\;\frac{\frac{x}{-t}}{z}\\


\end{array}
\end{array}
Derivation
  1. Split input into 3 regimes
  2. if (*.f64 z t) < -1.00000000000000005e57

    1. Initial program 85.7%

      \[\frac{x}{y - z \cdot t} \]
    2. Add Preprocessing
    3. Taylor expanded in z around inf 83.8%

      \[\leadsto \frac{x}{\color{blue}{z \cdot \left(\frac{y}{z} - t\right)}} \]
    4. Step-by-step derivation
      1. clear-num83.1%

        \[\leadsto \color{blue}{\frac{1}{\frac{z \cdot \left(\frac{y}{z} - t\right)}{x}}} \]
      2. inv-pow83.1%

        \[\leadsto \color{blue}{{\left(\frac{z \cdot \left(\frac{y}{z} - t\right)}{x}\right)}^{-1}} \]
    5. Applied egg-rr83.1%

      \[\leadsto \color{blue}{{\left(\frac{z \cdot \left(\frac{y}{z} - t\right)}{x}\right)}^{-1}} \]
    6. Step-by-step derivation
      1. unpow-183.1%

        \[\leadsto \color{blue}{\frac{1}{\frac{z \cdot \left(\frac{y}{z} - t\right)}{x}}} \]
      2. associate-/l*97.2%

        \[\leadsto \frac{1}{\color{blue}{z \cdot \frac{\frac{y}{z} - t}{x}}} \]
    7. Simplified97.2%

      \[\leadsto \color{blue}{\frac{1}{z \cdot \frac{\frac{y}{z} - t}{x}}} \]
    8. Taylor expanded in x around 0 83.8%

      \[\leadsto \color{blue}{\frac{x}{z \cdot \left(\frac{y}{z} - t\right)}} \]
    9. Step-by-step derivation
      1. associate-/r*94.4%

        \[\leadsto \color{blue}{\frac{\frac{x}{z}}{\frac{y}{z} - t}} \]
    10. Simplified94.4%

      \[\leadsto \color{blue}{\frac{\frac{x}{z}}{\frac{y}{z} - t}} \]
    11. Taylor expanded in y around 0 85.1%

      \[\leadsto \frac{\frac{x}{z}}{\color{blue}{-1 \cdot t}} \]
    12. Step-by-step derivation
      1. neg-mul-185.1%

        \[\leadsto \frac{\frac{x}{z}}{\color{blue}{-t}} \]
    13. Simplified85.1%

      \[\leadsto \frac{\frac{x}{z}}{\color{blue}{-t}} \]

    if -1.00000000000000005e57 < (*.f64 z t) < 2.00000000000000004e-91

    1. Initial program 99.9%

      \[\frac{x}{y - z \cdot t} \]
    2. Add Preprocessing
    3. Taylor expanded in y around inf 85.6%

      \[\leadsto \color{blue}{\frac{x}{y}} \]

    if 2.00000000000000004e-91 < (*.f64 z t)

    1. Initial program 90.7%

      \[\frac{x}{y - z \cdot t} \]
    2. Add Preprocessing
    3. Taylor expanded in z around inf 65.2%

      \[\leadsto \color{blue}{\frac{-1 \cdot \frac{x}{t} + -1 \cdot \frac{x \cdot y}{{t}^{2} \cdot z}}{z}} \]
    4. Step-by-step derivation
      1. distribute-lft-out65.2%

        \[\leadsto \frac{\color{blue}{-1 \cdot \left(\frac{x}{t} + \frac{x \cdot y}{{t}^{2} \cdot z}\right)}}{z} \]
      2. associate-*r/65.2%

        \[\leadsto \color{blue}{-1 \cdot \frac{\frac{x}{t} + \frac{x \cdot y}{{t}^{2} \cdot z}}{z}} \]
      3. mul-1-neg65.2%

        \[\leadsto \color{blue}{-\frac{\frac{x}{t} + \frac{x \cdot y}{{t}^{2} \cdot z}}{z}} \]
      4. *-commutative65.2%

        \[\leadsto -\frac{\frac{x}{t} + \frac{x \cdot y}{\color{blue}{z \cdot {t}^{2}}}}{z} \]
    5. Simplified65.2%

      \[\leadsto \color{blue}{-\frac{\frac{x}{t} + \frac{x \cdot y}{z \cdot {t}^{2}}}{z}} \]
    6. Taylor expanded in t around inf 72.2%

      \[\leadsto -\frac{\color{blue}{\frac{x}{t}}}{z} \]
  3. Recombined 3 regimes into one program.
  4. Final simplification81.6%

    \[\leadsto \begin{array}{l} \mathbf{if}\;z \cdot t \leq -1 \cdot 10^{+57}:\\ \;\;\;\;\frac{\frac{x}{z}}{-t}\\ \mathbf{elif}\;z \cdot t \leq 2 \cdot 10^{-91}:\\ \;\;\;\;\frac{x}{y}\\ \mathbf{else}:\\ \;\;\;\;\frac{\frac{x}{-t}}{z}\\ \end{array} \]
  5. Add Preprocessing

Alternative 6: 62.7% accurate, 0.4× speedup?

\[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;z \cdot t \leq -5 \cdot 10^{+204} \lor \neg \left(z \cdot t \leq 5 \cdot 10^{+226}\right):\\ \;\;\;\;\frac{x}{z \cdot t}\\ \mathbf{else}:\\ \;\;\;\;\frac{x}{y}\\ \end{array} \end{array} \]
(FPCore (x y z t)
 :precision binary64
 (if (or (<= (* z t) -5e+204) (not (<= (* z t) 5e+226)))
   (/ x (* z t))
   (/ x y)))
double code(double x, double y, double z, double t) {
	double tmp;
	if (((z * t) <= -5e+204) || !((z * t) <= 5e+226)) {
		tmp = x / (z * t);
	} else {
		tmp = x / y;
	}
	return tmp;
}
real(8) function code(x, y, z, t)
    real(8), intent (in) :: x
    real(8), intent (in) :: y
    real(8), intent (in) :: z
    real(8), intent (in) :: t
    real(8) :: tmp
    if (((z * t) <= (-5d+204)) .or. (.not. ((z * t) <= 5d+226))) then
        tmp = x / (z * t)
    else
        tmp = x / y
    end if
    code = tmp
end function
public static double code(double x, double y, double z, double t) {
	double tmp;
	if (((z * t) <= -5e+204) || !((z * t) <= 5e+226)) {
		tmp = x / (z * t);
	} else {
		tmp = x / y;
	}
	return tmp;
}
def code(x, y, z, t):
	tmp = 0
	if ((z * t) <= -5e+204) or not ((z * t) <= 5e+226):
		tmp = x / (z * t)
	else:
		tmp = x / y
	return tmp
function code(x, y, z, t)
	tmp = 0.0
	if ((Float64(z * t) <= -5e+204) || !(Float64(z * t) <= 5e+226))
		tmp = Float64(x / Float64(z * t));
	else
		tmp = Float64(x / y);
	end
	return tmp
end
function tmp_2 = code(x, y, z, t)
	tmp = 0.0;
	if (((z * t) <= -5e+204) || ~(((z * t) <= 5e+226)))
		tmp = x / (z * t);
	else
		tmp = x / y;
	end
	tmp_2 = tmp;
end
code[x_, y_, z_, t_] := If[Or[LessEqual[N[(z * t), $MachinePrecision], -5e+204], N[Not[LessEqual[N[(z * t), $MachinePrecision], 5e+226]], $MachinePrecision]], N[(x / N[(z * t), $MachinePrecision]), $MachinePrecision], N[(x / y), $MachinePrecision]]
\begin{array}{l}

\\
\begin{array}{l}
\mathbf{if}\;z \cdot t \leq -5 \cdot 10^{+204} \lor \neg \left(z \cdot t \leq 5 \cdot 10^{+226}\right):\\
\;\;\;\;\frac{x}{z \cdot t}\\

\mathbf{else}:\\
\;\;\;\;\frac{x}{y}\\


\end{array}
\end{array}
Derivation
  1. Split input into 2 regimes
  2. if (*.f64 z t) < -5.00000000000000008e204 or 5.0000000000000005e226 < (*.f64 z t)

    1. Initial program 71.0%

      \[\frac{x}{y - z \cdot t} \]
    2. Add Preprocessing
    3. Taylor expanded in t around inf 70.9%

      \[\leadsto \frac{x}{\color{blue}{t \cdot \left(\frac{y}{t} - z\right)}} \]
    4. Taylor expanded in t around inf 68.1%

      \[\leadsto \color{blue}{-1 \cdot \frac{x}{t \cdot z}} \]
    5. Step-by-step derivation
      1. associate-*r/68.1%

        \[\leadsto \color{blue}{\frac{-1 \cdot x}{t \cdot z}} \]
      2. neg-mul-168.1%

        \[\leadsto \frac{\color{blue}{-x}}{t \cdot z} \]
      3. *-commutative68.1%

        \[\leadsto \frac{-x}{\color{blue}{z \cdot t}} \]
    6. Simplified68.1%

      \[\leadsto \color{blue}{\frac{-x}{z \cdot t}} \]
    7. Step-by-step derivation
      1. neg-sub068.1%

        \[\leadsto \frac{\color{blue}{0 - x}}{z \cdot t} \]
      2. sub-neg68.1%

        \[\leadsto \frac{\color{blue}{0 + \left(-x\right)}}{z \cdot t} \]
      3. add-sqr-sqrt36.6%

        \[\leadsto \frac{0 + \color{blue}{\sqrt{-x} \cdot \sqrt{-x}}}{z \cdot t} \]
      4. sqrt-unprod57.6%

        \[\leadsto \frac{0 + \color{blue}{\sqrt{\left(-x\right) \cdot \left(-x\right)}}}{z \cdot t} \]
      5. sqr-neg57.6%

        \[\leadsto \frac{0 + \sqrt{\color{blue}{x \cdot x}}}{z \cdot t} \]
      6. sqrt-unprod25.6%

        \[\leadsto \frac{0 + \color{blue}{\sqrt{x} \cdot \sqrt{x}}}{z \cdot t} \]
      7. add-sqr-sqrt55.5%

        \[\leadsto \frac{0 + \color{blue}{x}}{z \cdot t} \]
    8. Applied egg-rr55.5%

      \[\leadsto \frac{\color{blue}{0 + x}}{z \cdot t} \]
    9. Step-by-step derivation
      1. +-lft-identity55.5%

        \[\leadsto \frac{\color{blue}{x}}{z \cdot t} \]
    10. Simplified55.5%

      \[\leadsto \frac{\color{blue}{x}}{z \cdot t} \]

    if -5.00000000000000008e204 < (*.f64 z t) < 5.0000000000000005e226

    1. Initial program 99.8%

      \[\frac{x}{y - z \cdot t} \]
    2. Add Preprocessing
    3. Taylor expanded in y around inf 66.3%

      \[\leadsto \color{blue}{\frac{x}{y}} \]
  3. Recombined 2 regimes into one program.
  4. Final simplification64.2%

    \[\leadsto \begin{array}{l} \mathbf{if}\;z \cdot t \leq -5 \cdot 10^{+204} \lor \neg \left(z \cdot t \leq 5 \cdot 10^{+226}\right):\\ \;\;\;\;\frac{x}{z \cdot t}\\ \mathbf{else}:\\ \;\;\;\;\frac{x}{y}\\ \end{array} \]
  5. Add Preprocessing

Alternative 7: 54.5% accurate, 2.3× speedup?

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

\\
\frac{x}{y}
\end{array}
Derivation
  1. Initial program 94.3%

    \[\frac{x}{y - z \cdot t} \]
  2. Add Preprocessing
  3. Taylor expanded in y around inf 56.2%

    \[\leadsto \color{blue}{\frac{x}{y}} \]
  4. Add Preprocessing

Developer Target 1: 96.6% accurate, 0.3× speedup?

\[\begin{array}{l} \\ \begin{array}{l} t_1 := \frac{1}{\frac{y}{x} - \frac{z}{x} \cdot t}\\ \mathbf{if}\;x < -1.618195973607049 \cdot 10^{+50}:\\ \;\;\;\;t\_1\\ \mathbf{elif}\;x < 2.1378306434876444 \cdot 10^{+131}:\\ \;\;\;\;\frac{x}{y - z \cdot t}\\ \mathbf{else}:\\ \;\;\;\;t\_1\\ \end{array} \end{array} \]
(FPCore (x y z t)
 :precision binary64
 (let* ((t_1 (/ 1.0 (- (/ y x) (* (/ z x) t)))))
   (if (< x -1.618195973607049e+50)
     t_1
     (if (< x 2.1378306434876444e+131) (/ x (- y (* z t))) t_1))))
double code(double x, double y, double z, double t) {
	double t_1 = 1.0 / ((y / x) - ((z / x) * t));
	double tmp;
	if (x < -1.618195973607049e+50) {
		tmp = t_1;
	} else if (x < 2.1378306434876444e+131) {
		tmp = x / (y - (z * t));
	} else {
		tmp = t_1;
	}
	return tmp;
}
real(8) function code(x, y, z, t)
    real(8), intent (in) :: x
    real(8), intent (in) :: y
    real(8), intent (in) :: z
    real(8), intent (in) :: t
    real(8) :: t_1
    real(8) :: tmp
    t_1 = 1.0d0 / ((y / x) - ((z / x) * t))
    if (x < (-1.618195973607049d+50)) then
        tmp = t_1
    else if (x < 2.1378306434876444d+131) then
        tmp = x / (y - (z * t))
    else
        tmp = t_1
    end if
    code = tmp
end function
public static double code(double x, double y, double z, double t) {
	double t_1 = 1.0 / ((y / x) - ((z / x) * t));
	double tmp;
	if (x < -1.618195973607049e+50) {
		tmp = t_1;
	} else if (x < 2.1378306434876444e+131) {
		tmp = x / (y - (z * t));
	} else {
		tmp = t_1;
	}
	return tmp;
}
def code(x, y, z, t):
	t_1 = 1.0 / ((y / x) - ((z / x) * t))
	tmp = 0
	if x < -1.618195973607049e+50:
		tmp = t_1
	elif x < 2.1378306434876444e+131:
		tmp = x / (y - (z * t))
	else:
		tmp = t_1
	return tmp
function code(x, y, z, t)
	t_1 = Float64(1.0 / Float64(Float64(y / x) - Float64(Float64(z / x) * t)))
	tmp = 0.0
	if (x < -1.618195973607049e+50)
		tmp = t_1;
	elseif (x < 2.1378306434876444e+131)
		tmp = Float64(x / Float64(y - Float64(z * t)));
	else
		tmp = t_1;
	end
	return tmp
end
function tmp_2 = code(x, y, z, t)
	t_1 = 1.0 / ((y / x) - ((z / x) * t));
	tmp = 0.0;
	if (x < -1.618195973607049e+50)
		tmp = t_1;
	elseif (x < 2.1378306434876444e+131)
		tmp = x / (y - (z * t));
	else
		tmp = t_1;
	end
	tmp_2 = tmp;
end
code[x_, y_, z_, t_] := Block[{t$95$1 = N[(1.0 / N[(N[(y / x), $MachinePrecision] - N[(N[(z / x), $MachinePrecision] * t), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]}, If[Less[x, -1.618195973607049e+50], t$95$1, If[Less[x, 2.1378306434876444e+131], N[(x / N[(y - N[(z * t), $MachinePrecision]), $MachinePrecision]), $MachinePrecision], t$95$1]]]
\begin{array}{l}

\\
\begin{array}{l}
t_1 := \frac{1}{\frac{y}{x} - \frac{z}{x} \cdot t}\\
\mathbf{if}\;x < -1.618195973607049 \cdot 10^{+50}:\\
\;\;\;\;t\_1\\

\mathbf{elif}\;x < 2.1378306434876444 \cdot 10^{+131}:\\
\;\;\;\;\frac{x}{y - z \cdot t}\\

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


\end{array}
\end{array}

Reproduce

?
herbie shell --seed 2024157 
(FPCore (x y z t)
  :name "Diagrams.Solve.Tridiagonal:solveTriDiagonal from diagrams-solve-0.1, B"
  :precision binary64

  :alt
  (! :herbie-platform default (if (< x -161819597360704900000000000000000000000000000000000) (/ 1 (- (/ y x) (* (/ z x) t))) (if (< x 213783064348764440000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000) (/ x (- y (* z t))) (/ 1 (- (/ y x) (* (/ z x) t))))))

  (/ x (- y (* z t))))