Diagrams.Solve.Tridiagonal:solveCyclicTriDiagonal from diagrams-solve-0.1, A

Percentage Accurate: 92.7% → 98.8%
Time: 4.0s
Alternatives: 4
Speedup: 0.5×

Specification

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

\\
\frac{x \cdot y}{z}
\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 4 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: 92.7% accurate, 1.0× speedup?

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

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

Alternative 1: 98.8% accurate, 0.4× speedup?

\[\begin{array}{l} x_m = \left|x\right| \\ x_s = \mathsf{copysign}\left(1, x\right) \\ y_m = \left|y\right| \\ y_s = \mathsf{copysign}\left(1, y\right) \\ z_m = \left|z\right| \\ z_s = \mathsf{copysign}\left(1, z\right) \\ [x_m, y_m, z_m] = \mathsf{sort}([x_m, y_m, z_m])\\ \\ z\_s \cdot \left(y\_s \cdot \left(x\_s \cdot \begin{array}{l} \mathbf{if}\;\frac{x\_m \cdot y\_m}{z\_m} \leq 10^{+93}:\\ \;\;\;\;x\_m \cdot \frac{y\_m}{z\_m}\\ \mathbf{else}:\\ \;\;\;\;\frac{y\_m}{\frac{z\_m}{x\_m}}\\ \end{array}\right)\right) \end{array} \]
x_m = (fabs.f64 x)
x_s = (copysign.f64 1 x)
y_m = (fabs.f64 y)
y_s = (copysign.f64 1 y)
z_m = (fabs.f64 z)
z_s = (copysign.f64 1 z)
NOTE: x_m, y_m, and z_m should be sorted in increasing order before calling this function.
(FPCore (z_s y_s x_s x_m y_m z_m)
 :precision binary64
 (*
  z_s
  (*
   y_s
   (*
    x_s
    (if (<= (/ (* x_m y_m) z_m) 1e+93)
      (* x_m (/ y_m z_m))
      (/ y_m (/ z_m x_m)))))))
x_m = fabs(x);
x_s = copysign(1.0, x);
y_m = fabs(y);
y_s = copysign(1.0, y);
z_m = fabs(z);
z_s = copysign(1.0, z);
assert(x_m < y_m && y_m < z_m);
double code(double z_s, double y_s, double x_s, double x_m, double y_m, double z_m) {
	double tmp;
	if (((x_m * y_m) / z_m) <= 1e+93) {
		tmp = x_m * (y_m / z_m);
	} else {
		tmp = y_m / (z_m / x_m);
	}
	return z_s * (y_s * (x_s * tmp));
}
x_m = abs(x)
x_s = copysign(1.0d0, x)
y_m = abs(y)
y_s = copysign(1.0d0, y)
z_m = abs(z)
z_s = copysign(1.0d0, z)
NOTE: x_m, y_m, and z_m should be sorted in increasing order before calling this function.
real(8) function code(z_s, y_s, x_s, x_m, y_m, z_m)
    real(8), intent (in) :: z_s
    real(8), intent (in) :: y_s
    real(8), intent (in) :: x_s
    real(8), intent (in) :: x_m
    real(8), intent (in) :: y_m
    real(8), intent (in) :: z_m
    real(8) :: tmp
    if (((x_m * y_m) / z_m) <= 1d+93) then
        tmp = x_m * (y_m / z_m)
    else
        tmp = y_m / (z_m / x_m)
    end if
    code = z_s * (y_s * (x_s * tmp))
end function
x_m = Math.abs(x);
x_s = Math.copySign(1.0, x);
y_m = Math.abs(y);
y_s = Math.copySign(1.0, y);
z_m = Math.abs(z);
z_s = Math.copySign(1.0, z);
assert x_m < y_m && y_m < z_m;
public static double code(double z_s, double y_s, double x_s, double x_m, double y_m, double z_m) {
	double tmp;
	if (((x_m * y_m) / z_m) <= 1e+93) {
		tmp = x_m * (y_m / z_m);
	} else {
		tmp = y_m / (z_m / x_m);
	}
	return z_s * (y_s * (x_s * tmp));
}
x_m = math.fabs(x)
x_s = math.copysign(1.0, x)
y_m = math.fabs(y)
y_s = math.copysign(1.0, y)
z_m = math.fabs(z)
z_s = math.copysign(1.0, z)
[x_m, y_m, z_m] = sort([x_m, y_m, z_m])
def code(z_s, y_s, x_s, x_m, y_m, z_m):
	tmp = 0
	if ((x_m * y_m) / z_m) <= 1e+93:
		tmp = x_m * (y_m / z_m)
	else:
		tmp = y_m / (z_m / x_m)
	return z_s * (y_s * (x_s * tmp))
x_m = abs(x)
x_s = copysign(1.0, x)
y_m = abs(y)
y_s = copysign(1.0, y)
z_m = abs(z)
z_s = copysign(1.0, z)
x_m, y_m, z_m = sort([x_m, y_m, z_m])
function code(z_s, y_s, x_s, x_m, y_m, z_m)
	tmp = 0.0
	if (Float64(Float64(x_m * y_m) / z_m) <= 1e+93)
		tmp = Float64(x_m * Float64(y_m / z_m));
	else
		tmp = Float64(y_m / Float64(z_m / x_m));
	end
	return Float64(z_s * Float64(y_s * Float64(x_s * tmp)))
end
x_m = abs(x);
x_s = sign(x) * abs(1.0);
y_m = abs(y);
y_s = sign(y) * abs(1.0);
z_m = abs(z);
z_s = sign(z) * abs(1.0);
x_m, y_m, z_m = num2cell(sort([x_m, y_m, z_m])){:}
function tmp_2 = code(z_s, y_s, x_s, x_m, y_m, z_m)
	tmp = 0.0;
	if (((x_m * y_m) / z_m) <= 1e+93)
		tmp = x_m * (y_m / z_m);
	else
		tmp = y_m / (z_m / x_m);
	end
	tmp_2 = z_s * (y_s * (x_s * tmp));
end
x_m = N[Abs[x], $MachinePrecision]
x_s = N[With[{TMP1 = Abs[1.0], TMP2 = Sign[x]}, TMP1 * If[TMP2 == 0, 1, TMP2]], $MachinePrecision]
y_m = N[Abs[y], $MachinePrecision]
y_s = N[With[{TMP1 = Abs[1.0], TMP2 = Sign[y]}, TMP1 * If[TMP2 == 0, 1, TMP2]], $MachinePrecision]
z_m = N[Abs[z], $MachinePrecision]
z_s = N[With[{TMP1 = Abs[1.0], TMP2 = Sign[z]}, TMP1 * If[TMP2 == 0, 1, TMP2]], $MachinePrecision]
NOTE: x_m, y_m, and z_m should be sorted in increasing order before calling this function.
code[z$95$s_, y$95$s_, x$95$s_, x$95$m_, y$95$m_, z$95$m_] := N[(z$95$s * N[(y$95$s * N[(x$95$s * If[LessEqual[N[(N[(x$95$m * y$95$m), $MachinePrecision] / z$95$m), $MachinePrecision], 1e+93], N[(x$95$m * N[(y$95$m / z$95$m), $MachinePrecision]), $MachinePrecision], N[(y$95$m / N[(z$95$m / x$95$m), $MachinePrecision]), $MachinePrecision]]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
x_m = \left|x\right|
\\
x_s = \mathsf{copysign}\left(1, x\right)
\\
y_m = \left|y\right|
\\
y_s = \mathsf{copysign}\left(1, y\right)
\\
z_m = \left|z\right|
\\
z_s = \mathsf{copysign}\left(1, z\right)
\\
[x_m, y_m, z_m] = \mathsf{sort}([x_m, y_m, z_m])\\
\\
z\_s \cdot \left(y\_s \cdot \left(x\_s \cdot \begin{array}{l}
\mathbf{if}\;\frac{x\_m \cdot y\_m}{z\_m} \leq 10^{+93}:\\
\;\;\;\;x\_m \cdot \frac{y\_m}{z\_m}\\

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


\end{array}\right)\right)
\end{array}
Derivation
  1. Split input into 2 regimes
  2. if (/.f64 (*.f64 x y) z) < 1.00000000000000004e93

    1. Initial program 93.8%

      \[\frac{x \cdot y}{z} \]
    2. Step-by-step derivation
      1. associate-*r/90.8%

        \[\leadsto \color{blue}{x \cdot \frac{y}{z}} \]
    3. Simplified90.8%

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

    if 1.00000000000000004e93 < (/.f64 (*.f64 x y) z)

    1. Initial program 88.8%

      \[\frac{x \cdot y}{z} \]
    2. Step-by-step derivation
      1. associate-*r/90.7%

        \[\leadsto \color{blue}{x \cdot \frac{y}{z}} \]
    3. Simplified90.7%

      \[\leadsto \color{blue}{x \cdot \frac{y}{z}} \]
    4. Add Preprocessing
    5. Step-by-step derivation
      1. *-commutative90.7%

        \[\leadsto \color{blue}{\frac{y}{z} \cdot x} \]
      2. associate-*l/88.8%

        \[\leadsto \color{blue}{\frac{y \cdot x}{z}} \]
      3. associate-/l*86.5%

        \[\leadsto \color{blue}{\frac{y}{\frac{z}{x}}} \]
    6. Applied egg-rr86.5%

      \[\leadsto \color{blue}{\frac{y}{\frac{z}{x}}} \]
  3. Recombined 2 regimes into one program.
  4. Final simplification90.1%

    \[\leadsto \begin{array}{l} \mathbf{if}\;\frac{x \cdot y}{z} \leq 10^{+93}:\\ \;\;\;\;x \cdot \frac{y}{z}\\ \mathbf{else}:\\ \;\;\;\;\frac{y}{\frac{z}{x}}\\ \end{array} \]
  5. Add Preprocessing

Alternative 2: 99.7% accurate, 0.5× speedup?

\[\begin{array}{l} x_m = \left|x\right| \\ x_s = \mathsf{copysign}\left(1, x\right) \\ y_m = \left|y\right| \\ y_s = \mathsf{copysign}\left(1, y\right) \\ z_m = \left|z\right| \\ z_s = \mathsf{copysign}\left(1, z\right) \\ [x_m, y_m, z_m] = \mathsf{sort}([x_m, y_m, z_m])\\ \\ z\_s \cdot \left(y\_s \cdot \left(x\_s \cdot \begin{array}{l} \mathbf{if}\;z\_m \leq 9.5 \cdot 10^{-12}:\\ \;\;\;\;y\_m \cdot \frac{x\_m}{z\_m}\\ \mathbf{else}:\\ \;\;\;\;x\_m \cdot \frac{y\_m}{z\_m}\\ \end{array}\right)\right) \end{array} \]
x_m = (fabs.f64 x)
x_s = (copysign.f64 1 x)
y_m = (fabs.f64 y)
y_s = (copysign.f64 1 y)
z_m = (fabs.f64 z)
z_s = (copysign.f64 1 z)
NOTE: x_m, y_m, and z_m should be sorted in increasing order before calling this function.
(FPCore (z_s y_s x_s x_m y_m z_m)
 :precision binary64
 (*
  z_s
  (*
   y_s
   (* x_s (if (<= z_m 9.5e-12) (* y_m (/ x_m z_m)) (* x_m (/ y_m z_m)))))))
x_m = fabs(x);
x_s = copysign(1.0, x);
y_m = fabs(y);
y_s = copysign(1.0, y);
z_m = fabs(z);
z_s = copysign(1.0, z);
assert(x_m < y_m && y_m < z_m);
double code(double z_s, double y_s, double x_s, double x_m, double y_m, double z_m) {
	double tmp;
	if (z_m <= 9.5e-12) {
		tmp = y_m * (x_m / z_m);
	} else {
		tmp = x_m * (y_m / z_m);
	}
	return z_s * (y_s * (x_s * tmp));
}
x_m = abs(x)
x_s = copysign(1.0d0, x)
y_m = abs(y)
y_s = copysign(1.0d0, y)
z_m = abs(z)
z_s = copysign(1.0d0, z)
NOTE: x_m, y_m, and z_m should be sorted in increasing order before calling this function.
real(8) function code(z_s, y_s, x_s, x_m, y_m, z_m)
    real(8), intent (in) :: z_s
    real(8), intent (in) :: y_s
    real(8), intent (in) :: x_s
    real(8), intent (in) :: x_m
    real(8), intent (in) :: y_m
    real(8), intent (in) :: z_m
    real(8) :: tmp
    if (z_m <= 9.5d-12) then
        tmp = y_m * (x_m / z_m)
    else
        tmp = x_m * (y_m / z_m)
    end if
    code = z_s * (y_s * (x_s * tmp))
end function
x_m = Math.abs(x);
x_s = Math.copySign(1.0, x);
y_m = Math.abs(y);
y_s = Math.copySign(1.0, y);
z_m = Math.abs(z);
z_s = Math.copySign(1.0, z);
assert x_m < y_m && y_m < z_m;
public static double code(double z_s, double y_s, double x_s, double x_m, double y_m, double z_m) {
	double tmp;
	if (z_m <= 9.5e-12) {
		tmp = y_m * (x_m / z_m);
	} else {
		tmp = x_m * (y_m / z_m);
	}
	return z_s * (y_s * (x_s * tmp));
}
x_m = math.fabs(x)
x_s = math.copysign(1.0, x)
y_m = math.fabs(y)
y_s = math.copysign(1.0, y)
z_m = math.fabs(z)
z_s = math.copysign(1.0, z)
[x_m, y_m, z_m] = sort([x_m, y_m, z_m])
def code(z_s, y_s, x_s, x_m, y_m, z_m):
	tmp = 0
	if z_m <= 9.5e-12:
		tmp = y_m * (x_m / z_m)
	else:
		tmp = x_m * (y_m / z_m)
	return z_s * (y_s * (x_s * tmp))
x_m = abs(x)
x_s = copysign(1.0, x)
y_m = abs(y)
y_s = copysign(1.0, y)
z_m = abs(z)
z_s = copysign(1.0, z)
x_m, y_m, z_m = sort([x_m, y_m, z_m])
function code(z_s, y_s, x_s, x_m, y_m, z_m)
	tmp = 0.0
	if (z_m <= 9.5e-12)
		tmp = Float64(y_m * Float64(x_m / z_m));
	else
		tmp = Float64(x_m * Float64(y_m / z_m));
	end
	return Float64(z_s * Float64(y_s * Float64(x_s * tmp)))
end
x_m = abs(x);
x_s = sign(x) * abs(1.0);
y_m = abs(y);
y_s = sign(y) * abs(1.0);
z_m = abs(z);
z_s = sign(z) * abs(1.0);
x_m, y_m, z_m = num2cell(sort([x_m, y_m, z_m])){:}
function tmp_2 = code(z_s, y_s, x_s, x_m, y_m, z_m)
	tmp = 0.0;
	if (z_m <= 9.5e-12)
		tmp = y_m * (x_m / z_m);
	else
		tmp = x_m * (y_m / z_m);
	end
	tmp_2 = z_s * (y_s * (x_s * tmp));
end
x_m = N[Abs[x], $MachinePrecision]
x_s = N[With[{TMP1 = Abs[1.0], TMP2 = Sign[x]}, TMP1 * If[TMP2 == 0, 1, TMP2]], $MachinePrecision]
y_m = N[Abs[y], $MachinePrecision]
y_s = N[With[{TMP1 = Abs[1.0], TMP2 = Sign[y]}, TMP1 * If[TMP2 == 0, 1, TMP2]], $MachinePrecision]
z_m = N[Abs[z], $MachinePrecision]
z_s = N[With[{TMP1 = Abs[1.0], TMP2 = Sign[z]}, TMP1 * If[TMP2 == 0, 1, TMP2]], $MachinePrecision]
NOTE: x_m, y_m, and z_m should be sorted in increasing order before calling this function.
code[z$95$s_, y$95$s_, x$95$s_, x$95$m_, y$95$m_, z$95$m_] := N[(z$95$s * N[(y$95$s * N[(x$95$s * If[LessEqual[z$95$m, 9.5e-12], N[(y$95$m * N[(x$95$m / z$95$m), $MachinePrecision]), $MachinePrecision], N[(x$95$m * N[(y$95$m / z$95$m), $MachinePrecision]), $MachinePrecision]]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
x_m = \left|x\right|
\\
x_s = \mathsf{copysign}\left(1, x\right)
\\
y_m = \left|y\right|
\\
y_s = \mathsf{copysign}\left(1, y\right)
\\
z_m = \left|z\right|
\\
z_s = \mathsf{copysign}\left(1, z\right)
\\
[x_m, y_m, z_m] = \mathsf{sort}([x_m, y_m, z_m])\\
\\
z\_s \cdot \left(y\_s \cdot \left(x\_s \cdot \begin{array}{l}
\mathbf{if}\;z\_m \leq 9.5 \cdot 10^{-12}:\\
\;\;\;\;y\_m \cdot \frac{x\_m}{z\_m}\\

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


\end{array}\right)\right)
\end{array}
Derivation
  1. Split input into 2 regimes
  2. if z < 9.4999999999999995e-12

    1. Initial program 91.8%

      \[\frac{x \cdot y}{z} \]
    2. Step-by-step derivation
      1. associate-*l/94.2%

        \[\leadsto \color{blue}{\frac{x}{z} \cdot y} \]
    3. Simplified94.2%

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

    if 9.4999999999999995e-12 < z

    1. Initial program 96.8%

      \[\frac{x \cdot y}{z} \]
    2. Step-by-step derivation
      1. associate-*r/91.3%

        \[\leadsto \color{blue}{x \cdot \frac{y}{z}} \]
    3. Simplified91.3%

      \[\leadsto \color{blue}{x \cdot \frac{y}{z}} \]
    4. Add Preprocessing
  3. Recombined 2 regimes into one program.
  4. Final simplification93.5%

    \[\leadsto \begin{array}{l} \mathbf{if}\;z \leq 9.5 \cdot 10^{-12}:\\ \;\;\;\;y \cdot \frac{x}{z}\\ \mathbf{else}:\\ \;\;\;\;x \cdot \frac{y}{z}\\ \end{array} \]
  5. Add Preprocessing

Alternative 3: 99.7% accurate, 0.5× speedup?

\[\begin{array}{l} x_m = \left|x\right| \\ x_s = \mathsf{copysign}\left(1, x\right) \\ y_m = \left|y\right| \\ y_s = \mathsf{copysign}\left(1, y\right) \\ z_m = \left|z\right| \\ z_s = \mathsf{copysign}\left(1, z\right) \\ [x_m, y_m, z_m] = \mathsf{sort}([x_m, y_m, z_m])\\ \\ z\_s \cdot \left(y\_s \cdot \left(x\_s \cdot \begin{array}{l} \mathbf{if}\;z\_m \leq 3 \cdot 10^{-31}:\\ \;\;\;\;y\_m \cdot \frac{x\_m}{z\_m}\\ \mathbf{else}:\\ \;\;\;\;\frac{x\_m}{\frac{z\_m}{y\_m}}\\ \end{array}\right)\right) \end{array} \]
x_m = (fabs.f64 x)
x_s = (copysign.f64 1 x)
y_m = (fabs.f64 y)
y_s = (copysign.f64 1 y)
z_m = (fabs.f64 z)
z_s = (copysign.f64 1 z)
NOTE: x_m, y_m, and z_m should be sorted in increasing order before calling this function.
(FPCore (z_s y_s x_s x_m y_m z_m)
 :precision binary64
 (*
  z_s
  (* y_s (* x_s (if (<= z_m 3e-31) (* y_m (/ x_m z_m)) (/ x_m (/ z_m y_m)))))))
x_m = fabs(x);
x_s = copysign(1.0, x);
y_m = fabs(y);
y_s = copysign(1.0, y);
z_m = fabs(z);
z_s = copysign(1.0, z);
assert(x_m < y_m && y_m < z_m);
double code(double z_s, double y_s, double x_s, double x_m, double y_m, double z_m) {
	double tmp;
	if (z_m <= 3e-31) {
		tmp = y_m * (x_m / z_m);
	} else {
		tmp = x_m / (z_m / y_m);
	}
	return z_s * (y_s * (x_s * tmp));
}
x_m = abs(x)
x_s = copysign(1.0d0, x)
y_m = abs(y)
y_s = copysign(1.0d0, y)
z_m = abs(z)
z_s = copysign(1.0d0, z)
NOTE: x_m, y_m, and z_m should be sorted in increasing order before calling this function.
real(8) function code(z_s, y_s, x_s, x_m, y_m, z_m)
    real(8), intent (in) :: z_s
    real(8), intent (in) :: y_s
    real(8), intent (in) :: x_s
    real(8), intent (in) :: x_m
    real(8), intent (in) :: y_m
    real(8), intent (in) :: z_m
    real(8) :: tmp
    if (z_m <= 3d-31) then
        tmp = y_m * (x_m / z_m)
    else
        tmp = x_m / (z_m / y_m)
    end if
    code = z_s * (y_s * (x_s * tmp))
end function
x_m = Math.abs(x);
x_s = Math.copySign(1.0, x);
y_m = Math.abs(y);
y_s = Math.copySign(1.0, y);
z_m = Math.abs(z);
z_s = Math.copySign(1.0, z);
assert x_m < y_m && y_m < z_m;
public static double code(double z_s, double y_s, double x_s, double x_m, double y_m, double z_m) {
	double tmp;
	if (z_m <= 3e-31) {
		tmp = y_m * (x_m / z_m);
	} else {
		tmp = x_m / (z_m / y_m);
	}
	return z_s * (y_s * (x_s * tmp));
}
x_m = math.fabs(x)
x_s = math.copysign(1.0, x)
y_m = math.fabs(y)
y_s = math.copysign(1.0, y)
z_m = math.fabs(z)
z_s = math.copysign(1.0, z)
[x_m, y_m, z_m] = sort([x_m, y_m, z_m])
def code(z_s, y_s, x_s, x_m, y_m, z_m):
	tmp = 0
	if z_m <= 3e-31:
		tmp = y_m * (x_m / z_m)
	else:
		tmp = x_m / (z_m / y_m)
	return z_s * (y_s * (x_s * tmp))
x_m = abs(x)
x_s = copysign(1.0, x)
y_m = abs(y)
y_s = copysign(1.0, y)
z_m = abs(z)
z_s = copysign(1.0, z)
x_m, y_m, z_m = sort([x_m, y_m, z_m])
function code(z_s, y_s, x_s, x_m, y_m, z_m)
	tmp = 0.0
	if (z_m <= 3e-31)
		tmp = Float64(y_m * Float64(x_m / z_m));
	else
		tmp = Float64(x_m / Float64(z_m / y_m));
	end
	return Float64(z_s * Float64(y_s * Float64(x_s * tmp)))
end
x_m = abs(x);
x_s = sign(x) * abs(1.0);
y_m = abs(y);
y_s = sign(y) * abs(1.0);
z_m = abs(z);
z_s = sign(z) * abs(1.0);
x_m, y_m, z_m = num2cell(sort([x_m, y_m, z_m])){:}
function tmp_2 = code(z_s, y_s, x_s, x_m, y_m, z_m)
	tmp = 0.0;
	if (z_m <= 3e-31)
		tmp = y_m * (x_m / z_m);
	else
		tmp = x_m / (z_m / y_m);
	end
	tmp_2 = z_s * (y_s * (x_s * tmp));
end
x_m = N[Abs[x], $MachinePrecision]
x_s = N[With[{TMP1 = Abs[1.0], TMP2 = Sign[x]}, TMP1 * If[TMP2 == 0, 1, TMP2]], $MachinePrecision]
y_m = N[Abs[y], $MachinePrecision]
y_s = N[With[{TMP1 = Abs[1.0], TMP2 = Sign[y]}, TMP1 * If[TMP2 == 0, 1, TMP2]], $MachinePrecision]
z_m = N[Abs[z], $MachinePrecision]
z_s = N[With[{TMP1 = Abs[1.0], TMP2 = Sign[z]}, TMP1 * If[TMP2 == 0, 1, TMP2]], $MachinePrecision]
NOTE: x_m, y_m, and z_m should be sorted in increasing order before calling this function.
code[z$95$s_, y$95$s_, x$95$s_, x$95$m_, y$95$m_, z$95$m_] := N[(z$95$s * N[(y$95$s * N[(x$95$s * If[LessEqual[z$95$m, 3e-31], N[(y$95$m * N[(x$95$m / z$95$m), $MachinePrecision]), $MachinePrecision], N[(x$95$m / N[(z$95$m / y$95$m), $MachinePrecision]), $MachinePrecision]]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
x_m = \left|x\right|
\\
x_s = \mathsf{copysign}\left(1, x\right)
\\
y_m = \left|y\right|
\\
y_s = \mathsf{copysign}\left(1, y\right)
\\
z_m = \left|z\right|
\\
z_s = \mathsf{copysign}\left(1, z\right)
\\
[x_m, y_m, z_m] = \mathsf{sort}([x_m, y_m, z_m])\\
\\
z\_s \cdot \left(y\_s \cdot \left(x\_s \cdot \begin{array}{l}
\mathbf{if}\;z\_m \leq 3 \cdot 10^{-31}:\\
\;\;\;\;y\_m \cdot \frac{x\_m}{z\_m}\\

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


\end{array}\right)\right)
\end{array}
Derivation
  1. Split input into 2 regimes
  2. if z < 2.99999999999999981e-31

    1. Initial program 91.7%

      \[\frac{x \cdot y}{z} \]
    2. Step-by-step derivation
      1. associate-*l/94.1%

        \[\leadsto \color{blue}{\frac{x}{z} \cdot y} \]
    3. Simplified94.1%

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

    if 2.99999999999999981e-31 < z

    1. Initial program 96.9%

      \[\frac{x \cdot y}{z} \]
    2. Step-by-step derivation
      1. associate-/l*91.6%

        \[\leadsto \color{blue}{\frac{x}{\frac{z}{y}}} \]
    3. Simplified91.6%

      \[\leadsto \color{blue}{\frac{x}{\frac{z}{y}}} \]
    4. Add Preprocessing
  3. Recombined 2 regimes into one program.
  4. Final simplification93.5%

    \[\leadsto \begin{array}{l} \mathbf{if}\;z \leq 3 \cdot 10^{-31}:\\ \;\;\;\;y \cdot \frac{x}{z}\\ \mathbf{else}:\\ \;\;\;\;\frac{x}{\frac{z}{y}}\\ \end{array} \]
  5. Add Preprocessing

Alternative 4: 92.3% accurate, 1.0× speedup?

\[\begin{array}{l} x_m = \left|x\right| \\ x_s = \mathsf{copysign}\left(1, x\right) \\ y_m = \left|y\right| \\ y_s = \mathsf{copysign}\left(1, y\right) \\ z_m = \left|z\right| \\ z_s = \mathsf{copysign}\left(1, z\right) \\ [x_m, y_m, z_m] = \mathsf{sort}([x_m, y_m, z_m])\\ \\ z\_s \cdot \left(y\_s \cdot \left(x\_s \cdot \left(x\_m \cdot \frac{y\_m}{z\_m}\right)\right)\right) \end{array} \]
x_m = (fabs.f64 x)
x_s = (copysign.f64 1 x)
y_m = (fabs.f64 y)
y_s = (copysign.f64 1 y)
z_m = (fabs.f64 z)
z_s = (copysign.f64 1 z)
NOTE: x_m, y_m, and z_m should be sorted in increasing order before calling this function.
(FPCore (z_s y_s x_s x_m y_m z_m)
 :precision binary64
 (* z_s (* y_s (* x_s (* x_m (/ y_m z_m))))))
x_m = fabs(x);
x_s = copysign(1.0, x);
y_m = fabs(y);
y_s = copysign(1.0, y);
z_m = fabs(z);
z_s = copysign(1.0, z);
assert(x_m < y_m && y_m < z_m);
double code(double z_s, double y_s, double x_s, double x_m, double y_m, double z_m) {
	return z_s * (y_s * (x_s * (x_m * (y_m / z_m))));
}
x_m = abs(x)
x_s = copysign(1.0d0, x)
y_m = abs(y)
y_s = copysign(1.0d0, y)
z_m = abs(z)
z_s = copysign(1.0d0, z)
NOTE: x_m, y_m, and z_m should be sorted in increasing order before calling this function.
real(8) function code(z_s, y_s, x_s, x_m, y_m, z_m)
    real(8), intent (in) :: z_s
    real(8), intent (in) :: y_s
    real(8), intent (in) :: x_s
    real(8), intent (in) :: x_m
    real(8), intent (in) :: y_m
    real(8), intent (in) :: z_m
    code = z_s * (y_s * (x_s * (x_m * (y_m / z_m))))
end function
x_m = Math.abs(x);
x_s = Math.copySign(1.0, x);
y_m = Math.abs(y);
y_s = Math.copySign(1.0, y);
z_m = Math.abs(z);
z_s = Math.copySign(1.0, z);
assert x_m < y_m && y_m < z_m;
public static double code(double z_s, double y_s, double x_s, double x_m, double y_m, double z_m) {
	return z_s * (y_s * (x_s * (x_m * (y_m / z_m))));
}
x_m = math.fabs(x)
x_s = math.copysign(1.0, x)
y_m = math.fabs(y)
y_s = math.copysign(1.0, y)
z_m = math.fabs(z)
z_s = math.copysign(1.0, z)
[x_m, y_m, z_m] = sort([x_m, y_m, z_m])
def code(z_s, y_s, x_s, x_m, y_m, z_m):
	return z_s * (y_s * (x_s * (x_m * (y_m / z_m))))
x_m = abs(x)
x_s = copysign(1.0, x)
y_m = abs(y)
y_s = copysign(1.0, y)
z_m = abs(z)
z_s = copysign(1.0, z)
x_m, y_m, z_m = sort([x_m, y_m, z_m])
function code(z_s, y_s, x_s, x_m, y_m, z_m)
	return Float64(z_s * Float64(y_s * Float64(x_s * Float64(x_m * Float64(y_m / z_m)))))
end
x_m = abs(x);
x_s = sign(x) * abs(1.0);
y_m = abs(y);
y_s = sign(y) * abs(1.0);
z_m = abs(z);
z_s = sign(z) * abs(1.0);
x_m, y_m, z_m = num2cell(sort([x_m, y_m, z_m])){:}
function tmp = code(z_s, y_s, x_s, x_m, y_m, z_m)
	tmp = z_s * (y_s * (x_s * (x_m * (y_m / z_m))));
end
x_m = N[Abs[x], $MachinePrecision]
x_s = N[With[{TMP1 = Abs[1.0], TMP2 = Sign[x]}, TMP1 * If[TMP2 == 0, 1, TMP2]], $MachinePrecision]
y_m = N[Abs[y], $MachinePrecision]
y_s = N[With[{TMP1 = Abs[1.0], TMP2 = Sign[y]}, TMP1 * If[TMP2 == 0, 1, TMP2]], $MachinePrecision]
z_m = N[Abs[z], $MachinePrecision]
z_s = N[With[{TMP1 = Abs[1.0], TMP2 = Sign[z]}, TMP1 * If[TMP2 == 0, 1, TMP2]], $MachinePrecision]
NOTE: x_m, y_m, and z_m should be sorted in increasing order before calling this function.
code[z$95$s_, y$95$s_, x$95$s_, x$95$m_, y$95$m_, z$95$m_] := N[(z$95$s * N[(y$95$s * N[(x$95$s * N[(x$95$m * N[(y$95$m / z$95$m), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
x_m = \left|x\right|
\\
x_s = \mathsf{copysign}\left(1, x\right)
\\
y_m = \left|y\right|
\\
y_s = \mathsf{copysign}\left(1, y\right)
\\
z_m = \left|z\right|
\\
z_s = \mathsf{copysign}\left(1, z\right)
\\
[x_m, y_m, z_m] = \mathsf{sort}([x_m, y_m, z_m])\\
\\
z\_s \cdot \left(y\_s \cdot \left(x\_s \cdot \left(x\_m \cdot \frac{y\_m}{z\_m}\right)\right)\right)
\end{array}
Derivation
  1. Initial program 93.0%

    \[\frac{x \cdot y}{z} \]
  2. Step-by-step derivation
    1. associate-*r/90.7%

      \[\leadsto \color{blue}{x \cdot \frac{y}{z}} \]
  3. Simplified90.7%

    \[\leadsto \color{blue}{x \cdot \frac{y}{z}} \]
  4. Add Preprocessing
  5. Final simplification90.7%

    \[\leadsto x \cdot \frac{y}{z} \]
  6. Add Preprocessing

Developer target: 87.5% accurate, 0.3× speedup?

\[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;z < -4.262230790519429 \cdot 10^{-138}:\\ \;\;\;\;\frac{x \cdot y}{z}\\ \mathbf{elif}\;z < 1.7042130660650472 \cdot 10^{-164}:\\ \;\;\;\;\frac{x}{\frac{z}{y}}\\ \mathbf{else}:\\ \;\;\;\;\frac{x}{z} \cdot y\\ \end{array} \end{array} \]
(FPCore (x y z)
 :precision binary64
 (if (< z -4.262230790519429e-138)
   (/ (* x y) z)
   (if (< z 1.7042130660650472e-164) (/ x (/ z y)) (* (/ x z) y))))
double code(double x, double y, double z) {
	double tmp;
	if (z < -4.262230790519429e-138) {
		tmp = (x * y) / z;
	} else if (z < 1.7042130660650472e-164) {
		tmp = x / (z / y);
	} else {
		tmp = (x / z) * y;
	}
	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) :: tmp
    if (z < (-4.262230790519429d-138)) then
        tmp = (x * y) / z
    else if (z < 1.7042130660650472d-164) then
        tmp = x / (z / y)
    else
        tmp = (x / z) * y
    end if
    code = tmp
end function
public static double code(double x, double y, double z) {
	double tmp;
	if (z < -4.262230790519429e-138) {
		tmp = (x * y) / z;
	} else if (z < 1.7042130660650472e-164) {
		tmp = x / (z / y);
	} else {
		tmp = (x / z) * y;
	}
	return tmp;
}
def code(x, y, z):
	tmp = 0
	if z < -4.262230790519429e-138:
		tmp = (x * y) / z
	elif z < 1.7042130660650472e-164:
		tmp = x / (z / y)
	else:
		tmp = (x / z) * y
	return tmp
function code(x, y, z)
	tmp = 0.0
	if (z < -4.262230790519429e-138)
		tmp = Float64(Float64(x * y) / z);
	elseif (z < 1.7042130660650472e-164)
		tmp = Float64(x / Float64(z / y));
	else
		tmp = Float64(Float64(x / z) * y);
	end
	return tmp
end
function tmp_2 = code(x, y, z)
	tmp = 0.0;
	if (z < -4.262230790519429e-138)
		tmp = (x * y) / z;
	elseif (z < 1.7042130660650472e-164)
		tmp = x / (z / y);
	else
		tmp = (x / z) * y;
	end
	tmp_2 = tmp;
end
code[x_, y_, z_] := If[Less[z, -4.262230790519429e-138], N[(N[(x * y), $MachinePrecision] / z), $MachinePrecision], If[Less[z, 1.7042130660650472e-164], N[(x / N[(z / y), $MachinePrecision]), $MachinePrecision], N[(N[(x / z), $MachinePrecision] * y), $MachinePrecision]]]
\begin{array}{l}

\\
\begin{array}{l}
\mathbf{if}\;z < -4.262230790519429 \cdot 10^{-138}:\\
\;\;\;\;\frac{x \cdot y}{z}\\

\mathbf{elif}\;z < 1.7042130660650472 \cdot 10^{-164}:\\
\;\;\;\;\frac{x}{\frac{z}{y}}\\

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


\end{array}
\end{array}

Reproduce

?
herbie shell --seed 2024040 
(FPCore (x y z)
  :name "Diagrams.Solve.Tridiagonal:solveCyclicTriDiagonal from diagrams-solve-0.1, A"
  :precision binary64

  :herbie-target
  (if (< z -4.262230790519429e-138) (/ (* x y) z) (if (< z 1.7042130660650472e-164) (/ x (/ z y)) (* (/ x z) y)))

  (/ (* x y) z))