Numeric.SpecFunctions:choose from math-functions-0.1.5.2

Percentage Accurate: 84.9% → 98.1%
Time: 6.7s
Alternatives: 4
Speedup: 1.1×

Specification

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

\\
\frac{x \cdot \left(y + z\right)}{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: 84.9% accurate, 1.0× speedup?

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

\\
\frac{x \cdot \left(y + z\right)}{z}
\end{array}

Alternative 1: 98.1% accurate, 0.8× speedup?

\[\begin{array}{l} x\_m = \left|x\right| \\ x\_s = \mathsf{copysign}\left(1, x\right) \\ x\_s \cdot \begin{array}{l} \mathbf{if}\;x\_m \leq 5 \cdot 10^{+26}:\\ \;\;\;\;\mathsf{fma}\left(\frac{x\_m}{z}, y, x\_m\right)\\ \mathbf{else}:\\ \;\;\;\;\mathsf{fma}\left(\frac{y}{z}, x\_m, x\_m\right)\\ \end{array} \end{array} \]
x\_m = (fabs.f64 x)
x\_s = (copysign.f64 #s(literal 1 binary64) x)
(FPCore (x_s x_m y z)
 :precision binary64
 (* x_s (if (<= x_m 5e+26) (fma (/ x_m z) y x_m) (fma (/ y z) x_m x_m))))
x\_m = fabs(x);
x\_s = copysign(1.0, x);
double code(double x_s, double x_m, double y, double z) {
	double tmp;
	if (x_m <= 5e+26) {
		tmp = fma((x_m / z), y, x_m);
	} else {
		tmp = fma((y / z), x_m, x_m);
	}
	return x_s * tmp;
}
x\_m = abs(x)
x\_s = copysign(1.0, x)
function code(x_s, x_m, y, z)
	tmp = 0.0
	if (x_m <= 5e+26)
		tmp = fma(Float64(x_m / z), y, x_m);
	else
		tmp = fma(Float64(y / z), x_m, x_m);
	end
	return Float64(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]
code[x$95$s_, x$95$m_, y_, z_] := N[(x$95$s * If[LessEqual[x$95$m, 5e+26], N[(N[(x$95$m / z), $MachinePrecision] * y + x$95$m), $MachinePrecision], N[(N[(y / z), $MachinePrecision] * x$95$m + x$95$m), $MachinePrecision]]), $MachinePrecision]
\begin{array}{l}
x\_m = \left|x\right|
\\
x\_s = \mathsf{copysign}\left(1, x\right)

\\
x\_s \cdot \begin{array}{l}
\mathbf{if}\;x\_m \leq 5 \cdot 10^{+26}:\\
\;\;\;\;\mathsf{fma}\left(\frac{x\_m}{z}, y, x\_m\right)\\

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


\end{array}
\end{array}
Derivation
  1. Split input into 2 regimes
  2. if x < 5.0000000000000001e26

    1. Initial program 89.8%

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

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

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

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

        \[\leadsto \frac{\color{blue}{z \cdot x + y \cdot x}}{z} \]
      5. lower-fma.f64N/A

        \[\leadsto \frac{\color{blue}{\mathsf{fma}\left(z, x, y \cdot x\right)}}{z} \]
      6. lower-*.f6489.8

        \[\leadsto \frac{\mathsf{fma}\left(z, x, \color{blue}{y \cdot x}\right)}{z} \]
    4. Applied rewrites89.8%

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

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

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

        \[\leadsto \mathsf{neg}\left(\color{blue}{x \cdot \frac{-1 \cdot y + -1 \cdot z}{z}}\right) \]
      3. distribute-rgt-neg-inN/A

        \[\leadsto \color{blue}{x \cdot \left(\mathsf{neg}\left(\frac{-1 \cdot y + -1 \cdot z}{z}\right)\right)} \]
      4. distribute-lft-outN/A

        \[\leadsto x \cdot \left(\mathsf{neg}\left(\frac{\color{blue}{-1 \cdot \left(y + z\right)}}{z}\right)\right) \]
      5. associate-*l/N/A

        \[\leadsto x \cdot \left(\mathsf{neg}\left(\color{blue}{\frac{-1}{z} \cdot \left(y + z\right)}\right)\right) \]
      6. distribute-rgt-neg-inN/A

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

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

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

        \[\leadsto x \cdot \left(\frac{-1}{z} \cdot \color{blue}{\left(-1 \cdot z + -1 \cdot y\right)}\right) \]
      10. distribute-lft-inN/A

        \[\leadsto x \cdot \color{blue}{\left(\frac{-1}{z} \cdot \left(-1 \cdot z\right) + \frac{-1}{z} \cdot \left(-1 \cdot y\right)\right)} \]
      11. associate-*l/N/A

        \[\leadsto x \cdot \left(\color{blue}{\frac{-1 \cdot \left(-1 \cdot z\right)}{z}} + \frac{-1}{z} \cdot \left(-1 \cdot y\right)\right) \]
      12. associate-*r*N/A

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

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

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

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

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

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

        \[\leadsto x \cdot \left(\frac{\color{blue}{\left(-1 \cdot -1\right)} \cdot y}{y} + \frac{-1}{z} \cdot \left(-1 \cdot y\right)\right) \]
      19. associate-*r*N/A

        \[\leadsto x \cdot \left(\frac{\color{blue}{-1 \cdot \left(-1 \cdot y\right)}}{y} + \frac{-1}{z} \cdot \left(-1 \cdot y\right)\right) \]
      20. associate-*l/N/A

        \[\leadsto x \cdot \left(\color{blue}{\frac{-1}{y} \cdot \left(-1 \cdot y\right)} + \frac{-1}{z} \cdot \left(-1 \cdot y\right)\right) \]
    7. Applied rewrites93.0%

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

    if 5.0000000000000001e26 < x

    1. Initial program 67.3%

      \[\frac{x \cdot \left(y + z\right)}{z} \]
    2. Add Preprocessing
    3. Taylor expanded in x around 0

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

        \[\leadsto \color{blue}{x \cdot \frac{y + z}{z}} \]
      2. *-lft-identityN/A

        \[\leadsto x \cdot \frac{y + \color{blue}{1 \cdot z}}{z} \]
      3. metadata-evalN/A

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

        \[\leadsto x \cdot \frac{\color{blue}{y - -1 \cdot z}}{z} \]
      5. div-subN/A

        \[\leadsto x \cdot \color{blue}{\left(\frac{y}{z} - \frac{-1 \cdot z}{z}\right)} \]
      6. mul-1-negN/A

        \[\leadsto x \cdot \left(\frac{y}{z} - \frac{\color{blue}{\mathsf{neg}\left(z\right)}}{z}\right) \]
      7. distribute-frac-negN/A

        \[\leadsto x \cdot \left(\frac{y}{z} - \color{blue}{\left(\mathsf{neg}\left(\frac{z}{z}\right)\right)}\right) \]
      8. *-inversesN/A

        \[\leadsto x \cdot \left(\frac{y}{z} - \left(\mathsf{neg}\left(\color{blue}{1}\right)\right)\right) \]
      9. *-inversesN/A

        \[\leadsto x \cdot \left(\frac{y}{z} - \left(\mathsf{neg}\left(\color{blue}{\frac{y}{y}}\right)\right)\right) \]
      10. distribute-frac-negN/A

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

        \[\leadsto x \cdot \left(\frac{y}{z} - \frac{\color{blue}{-1 \cdot y}}{y}\right) \]
      12. distribute-rgt-out--N/A

        \[\leadsto \color{blue}{\frac{y}{z} \cdot x - \frac{-1 \cdot y}{y} \cdot x} \]
      13. *-commutativeN/A

        \[\leadsto \color{blue}{x \cdot \frac{y}{z}} - \frac{-1 \cdot y}{y} \cdot x \]
      14. associate-/l*N/A

        \[\leadsto \color{blue}{\frac{x \cdot y}{z}} - \frac{-1 \cdot y}{y} \cdot x \]
      15. associate-*l/N/A

        \[\leadsto \frac{x \cdot y}{z} - \color{blue}{\frac{\left(-1 \cdot y\right) \cdot x}{y}} \]
      16. associate-*r/N/A

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

        \[\leadsto \frac{x \cdot y}{z} - \color{blue}{\left(y \cdot -1\right)} \cdot \frac{x}{y} \]
      18. associate-*r*N/A

        \[\leadsto \frac{x \cdot y}{z} - \color{blue}{y \cdot \left(-1 \cdot \frac{x}{y}\right)} \]
      19. associate-*r*N/A

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

        \[\leadsto \frac{x \cdot y}{z} - \color{blue}{\left(-1 \cdot y\right)} \cdot \frac{x}{y} \]
      21. mul-1-negN/A

        \[\leadsto \frac{x \cdot y}{z} - \color{blue}{\left(\mathsf{neg}\left(y\right)\right)} \cdot \frac{x}{y} \]
      22. cancel-sign-subN/A

        \[\leadsto \color{blue}{\frac{x \cdot y}{z} + y \cdot \frac{x}{y}} \]
    5. Applied rewrites99.9%

      \[\leadsto \color{blue}{\mathsf{fma}\left(\frac{y}{z}, x, x\right)} \]
  3. Recombined 2 regimes into one program.
  4. Final simplification94.4%

    \[\leadsto \begin{array}{l} \mathbf{if}\;x \leq 5 \cdot 10^{+26}:\\ \;\;\;\;\mathsf{fma}\left(\frac{x}{z}, y, x\right)\\ \mathbf{else}:\\ \;\;\;\;\mathsf{fma}\left(\frac{y}{z}, x, x\right)\\ \end{array} \]
  5. Add Preprocessing

Alternative 2: 70.6% accurate, 0.3× speedup?

\[\begin{array}{l} x\_m = \left|x\right| \\ x\_s = \mathsf{copysign}\left(1, x\right) \\ \begin{array}{l} t_0 := \frac{x\_m \cdot \left(y + z\right)}{z}\\ x\_s \cdot \begin{array}{l} \mathbf{if}\;t\_0 \leq 5 \cdot 10^{-302} \lor \neg \left(t\_0 \leq 5 \cdot 10^{+219}\right):\\ \;\;\;\;\frac{x\_m}{z} \cdot y\\ \mathbf{else}:\\ \;\;\;\;\frac{z \cdot x\_m}{z}\\ \end{array} \end{array} \end{array} \]
x\_m = (fabs.f64 x)
x\_s = (copysign.f64 #s(literal 1 binary64) x)
(FPCore (x_s x_m y z)
 :precision binary64
 (let* ((t_0 (/ (* x_m (+ y z)) z)))
   (*
    x_s
    (if (or (<= t_0 5e-302) (not (<= t_0 5e+219)))
      (* (/ x_m z) y)
      (/ (* z x_m) z)))))
x\_m = fabs(x);
x\_s = copysign(1.0, x);
double code(double x_s, double x_m, double y, double z) {
	double t_0 = (x_m * (y + z)) / z;
	double tmp;
	if ((t_0 <= 5e-302) || !(t_0 <= 5e+219)) {
		tmp = (x_m / z) * y;
	} else {
		tmp = (z * x_m) / z;
	}
	return x_s * tmp;
}
x\_m = abs(x)
x\_s = copysign(1.0d0, x)
real(8) function code(x_s, x_m, y, z)
    real(8), intent (in) :: x_s
    real(8), intent (in) :: x_m
    real(8), intent (in) :: y
    real(8), intent (in) :: z
    real(8) :: t_0
    real(8) :: tmp
    t_0 = (x_m * (y + z)) / z
    if ((t_0 <= 5d-302) .or. (.not. (t_0 <= 5d+219))) then
        tmp = (x_m / z) * y
    else
        tmp = (z * x_m) / z
    end if
    code = x_s * tmp
end function
x\_m = Math.abs(x);
x\_s = Math.copySign(1.0, x);
public static double code(double x_s, double x_m, double y, double z) {
	double t_0 = (x_m * (y + z)) / z;
	double tmp;
	if ((t_0 <= 5e-302) || !(t_0 <= 5e+219)) {
		tmp = (x_m / z) * y;
	} else {
		tmp = (z * x_m) / z;
	}
	return x_s * tmp;
}
x\_m = math.fabs(x)
x\_s = math.copysign(1.0, x)
def code(x_s, x_m, y, z):
	t_0 = (x_m * (y + z)) / z
	tmp = 0
	if (t_0 <= 5e-302) or not (t_0 <= 5e+219):
		tmp = (x_m / z) * y
	else:
		tmp = (z * x_m) / z
	return x_s * tmp
x\_m = abs(x)
x\_s = copysign(1.0, x)
function code(x_s, x_m, y, z)
	t_0 = Float64(Float64(x_m * Float64(y + z)) / z)
	tmp = 0.0
	if ((t_0 <= 5e-302) || !(t_0 <= 5e+219))
		tmp = Float64(Float64(x_m / z) * y);
	else
		tmp = Float64(Float64(z * x_m) / z);
	end
	return Float64(x_s * tmp)
end
x\_m = abs(x);
x\_s = sign(x) * abs(1.0);
function tmp_2 = code(x_s, x_m, y, z)
	t_0 = (x_m * (y + z)) / z;
	tmp = 0.0;
	if ((t_0 <= 5e-302) || ~((t_0 <= 5e+219)))
		tmp = (x_m / z) * y;
	else
		tmp = (z * x_m) / z;
	end
	tmp_2 = 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]
code[x$95$s_, x$95$m_, y_, z_] := Block[{t$95$0 = N[(N[(x$95$m * N[(y + z), $MachinePrecision]), $MachinePrecision] / z), $MachinePrecision]}, N[(x$95$s * If[Or[LessEqual[t$95$0, 5e-302], N[Not[LessEqual[t$95$0, 5e+219]], $MachinePrecision]], N[(N[(x$95$m / z), $MachinePrecision] * y), $MachinePrecision], N[(N[(z * x$95$m), $MachinePrecision] / z), $MachinePrecision]]), $MachinePrecision]]
\begin{array}{l}
x\_m = \left|x\right|
\\
x\_s = \mathsf{copysign}\left(1, x\right)

\\
\begin{array}{l}
t_0 := \frac{x\_m \cdot \left(y + z\right)}{z}\\
x\_s \cdot \begin{array}{l}
\mathbf{if}\;t\_0 \leq 5 \cdot 10^{-302} \lor \neg \left(t\_0 \leq 5 \cdot 10^{+219}\right):\\
\;\;\;\;\frac{x\_m}{z} \cdot y\\

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


\end{array}
\end{array}
\end{array}
Derivation
  1. Split input into 2 regimes
  2. if (/.f64 (*.f64 x (+.f64 y z)) z) < 5.00000000000000033e-302 or 5e219 < (/.f64 (*.f64 x (+.f64 y z)) z)

    1. Initial program 80.0%

      \[\frac{x \cdot \left(y + z\right)}{z} \]
    2. Add Preprocessing
    3. Taylor expanded in x around 0

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

        \[\leadsto \color{blue}{x \cdot \frac{y + z}{z}} \]
      2. *-lft-identityN/A

        \[\leadsto x \cdot \frac{y + \color{blue}{1 \cdot z}}{z} \]
      3. metadata-evalN/A

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

        \[\leadsto x \cdot \frac{\color{blue}{y - -1 \cdot z}}{z} \]
      5. div-subN/A

        \[\leadsto x \cdot \color{blue}{\left(\frac{y}{z} - \frac{-1 \cdot z}{z}\right)} \]
      6. mul-1-negN/A

        \[\leadsto x \cdot \left(\frac{y}{z} - \frac{\color{blue}{\mathsf{neg}\left(z\right)}}{z}\right) \]
      7. distribute-frac-negN/A

        \[\leadsto x \cdot \left(\frac{y}{z} - \color{blue}{\left(\mathsf{neg}\left(\frac{z}{z}\right)\right)}\right) \]
      8. *-inversesN/A

        \[\leadsto x \cdot \left(\frac{y}{z} - \left(\mathsf{neg}\left(\color{blue}{1}\right)\right)\right) \]
      9. *-inversesN/A

        \[\leadsto x \cdot \left(\frac{y}{z} - \left(\mathsf{neg}\left(\color{blue}{\frac{y}{y}}\right)\right)\right) \]
      10. distribute-frac-negN/A

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

        \[\leadsto x \cdot \left(\frac{y}{z} - \frac{\color{blue}{-1 \cdot y}}{y}\right) \]
      12. distribute-rgt-out--N/A

        \[\leadsto \color{blue}{\frac{y}{z} \cdot x - \frac{-1 \cdot y}{y} \cdot x} \]
      13. *-commutativeN/A

        \[\leadsto \color{blue}{x \cdot \frac{y}{z}} - \frac{-1 \cdot y}{y} \cdot x \]
      14. associate-/l*N/A

        \[\leadsto \color{blue}{\frac{x \cdot y}{z}} - \frac{-1 \cdot y}{y} \cdot x \]
      15. associate-*l/N/A

        \[\leadsto \frac{x \cdot y}{z} - \color{blue}{\frac{\left(-1 \cdot y\right) \cdot x}{y}} \]
      16. associate-*r/N/A

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

        \[\leadsto \frac{x \cdot y}{z} - \color{blue}{\left(y \cdot -1\right)} \cdot \frac{x}{y} \]
      18. associate-*r*N/A

        \[\leadsto \frac{x \cdot y}{z} - \color{blue}{y \cdot \left(-1 \cdot \frac{x}{y}\right)} \]
      19. associate-*r*N/A

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

        \[\leadsto \frac{x \cdot y}{z} - \color{blue}{\left(-1 \cdot y\right)} \cdot \frac{x}{y} \]
      21. mul-1-negN/A

        \[\leadsto \frac{x \cdot y}{z} - \color{blue}{\left(\mathsf{neg}\left(y\right)\right)} \cdot \frac{x}{y} \]
      22. cancel-sign-subN/A

        \[\leadsto \color{blue}{\frac{x \cdot y}{z} + y \cdot \frac{x}{y}} \]
    5. Applied rewrites96.3%

      \[\leadsto \color{blue}{\mathsf{fma}\left(\frac{y}{z}, x, x\right)} \]
    6. Taylor expanded in y around inf

      \[\leadsto \color{blue}{\frac{x \cdot y}{z}} \]
    7. Step-by-step derivation
      1. associate-*l/N/A

        \[\leadsto \color{blue}{\frac{x}{z} \cdot y} \]
      2. lower-*.f64N/A

        \[\leadsto \color{blue}{\frac{x}{z} \cdot y} \]
      3. lower-/.f6453.0

        \[\leadsto \color{blue}{\frac{x}{z}} \cdot y \]
    8. Applied rewrites53.0%

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

    if 5.00000000000000033e-302 < (/.f64 (*.f64 x (+.f64 y z)) z) < 5e219

    1. Initial program 98.7%

      \[\frac{x \cdot \left(y + z\right)}{z} \]
    2. Add Preprocessing
    3. Taylor expanded in y around 0

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

        \[\leadsto \frac{\color{blue}{z \cdot x}}{z} \]
      2. lower-*.f6452.2

        \[\leadsto \frac{\color{blue}{z \cdot x}}{z} \]
    5. Applied rewrites52.2%

      \[\leadsto \frac{\color{blue}{z \cdot x}}{z} \]
  3. Recombined 2 regimes into one program.
  4. Final simplification52.8%

    \[\leadsto \begin{array}{l} \mathbf{if}\;\frac{x \cdot \left(y + z\right)}{z} \leq 5 \cdot 10^{-302} \lor \neg \left(\frac{x \cdot \left(y + z\right)}{z} \leq 5 \cdot 10^{+219}\right):\\ \;\;\;\;\frac{x}{z} \cdot y\\ \mathbf{else}:\\ \;\;\;\;\frac{z \cdot x}{z}\\ \end{array} \]
  5. Add Preprocessing

Alternative 3: 96.2% accurate, 1.1× speedup?

\[\begin{array}{l} x\_m = \left|x\right| \\ x\_s = \mathsf{copysign}\left(1, x\right) \\ x\_s \cdot \mathsf{fma}\left(\frac{y}{z}, x\_m, x\_m\right) \end{array} \]
x\_m = (fabs.f64 x)
x\_s = (copysign.f64 #s(literal 1 binary64) x)
(FPCore (x_s x_m y z) :precision binary64 (* x_s (fma (/ y z) x_m x_m)))
x\_m = fabs(x);
x\_s = copysign(1.0, x);
double code(double x_s, double x_m, double y, double z) {
	return x_s * fma((y / z), x_m, x_m);
}
x\_m = abs(x)
x\_s = copysign(1.0, x)
function code(x_s, x_m, y, z)
	return Float64(x_s * fma(Float64(y / z), x_m, x_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]
code[x$95$s_, x$95$m_, y_, z_] := N[(x$95$s * N[(N[(y / z), $MachinePrecision] * x$95$m + x$95$m), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
x\_m = \left|x\right|
\\
x\_s = \mathsf{copysign}\left(1, x\right)

\\
x\_s \cdot \mathsf{fma}\left(\frac{y}{z}, x\_m, x\_m\right)
\end{array}
Derivation
  1. Initial program 85.3%

    \[\frac{x \cdot \left(y + z\right)}{z} \]
  2. Add Preprocessing
  3. Taylor expanded in x around 0

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

      \[\leadsto \color{blue}{x \cdot \frac{y + z}{z}} \]
    2. *-lft-identityN/A

      \[\leadsto x \cdot \frac{y + \color{blue}{1 \cdot z}}{z} \]
    3. metadata-evalN/A

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

      \[\leadsto x \cdot \frac{\color{blue}{y - -1 \cdot z}}{z} \]
    5. div-subN/A

      \[\leadsto x \cdot \color{blue}{\left(\frac{y}{z} - \frac{-1 \cdot z}{z}\right)} \]
    6. mul-1-negN/A

      \[\leadsto x \cdot \left(\frac{y}{z} - \frac{\color{blue}{\mathsf{neg}\left(z\right)}}{z}\right) \]
    7. distribute-frac-negN/A

      \[\leadsto x \cdot \left(\frac{y}{z} - \color{blue}{\left(\mathsf{neg}\left(\frac{z}{z}\right)\right)}\right) \]
    8. *-inversesN/A

      \[\leadsto x \cdot \left(\frac{y}{z} - \left(\mathsf{neg}\left(\color{blue}{1}\right)\right)\right) \]
    9. *-inversesN/A

      \[\leadsto x \cdot \left(\frac{y}{z} - \left(\mathsf{neg}\left(\color{blue}{\frac{y}{y}}\right)\right)\right) \]
    10. distribute-frac-negN/A

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

      \[\leadsto x \cdot \left(\frac{y}{z} - \frac{\color{blue}{-1 \cdot y}}{y}\right) \]
    12. distribute-rgt-out--N/A

      \[\leadsto \color{blue}{\frac{y}{z} \cdot x - \frac{-1 \cdot y}{y} \cdot x} \]
    13. *-commutativeN/A

      \[\leadsto \color{blue}{x \cdot \frac{y}{z}} - \frac{-1 \cdot y}{y} \cdot x \]
    14. associate-/l*N/A

      \[\leadsto \color{blue}{\frac{x \cdot y}{z}} - \frac{-1 \cdot y}{y} \cdot x \]
    15. associate-*l/N/A

      \[\leadsto \frac{x \cdot y}{z} - \color{blue}{\frac{\left(-1 \cdot y\right) \cdot x}{y}} \]
    16. associate-*r/N/A

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

      \[\leadsto \frac{x \cdot y}{z} - \color{blue}{\left(y \cdot -1\right)} \cdot \frac{x}{y} \]
    18. associate-*r*N/A

      \[\leadsto \frac{x \cdot y}{z} - \color{blue}{y \cdot \left(-1 \cdot \frac{x}{y}\right)} \]
    19. associate-*r*N/A

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

      \[\leadsto \frac{x \cdot y}{z} - \color{blue}{\left(-1 \cdot y\right)} \cdot \frac{x}{y} \]
    21. mul-1-negN/A

      \[\leadsto \frac{x \cdot y}{z} - \color{blue}{\left(\mathsf{neg}\left(y\right)\right)} \cdot \frac{x}{y} \]
    22. cancel-sign-subN/A

      \[\leadsto \color{blue}{\frac{x \cdot y}{z} + y \cdot \frac{x}{y}} \]
  5. Applied rewrites95.4%

    \[\leadsto \color{blue}{\mathsf{fma}\left(\frac{y}{z}, x, x\right)} \]
  6. Add Preprocessing

Alternative 4: 47.0% accurate, 1.2× speedup?

\[\begin{array}{l} x\_m = \left|x\right| \\ x\_s = \mathsf{copysign}\left(1, x\right) \\ x\_s \cdot \left(\frac{x\_m}{z} \cdot y\right) \end{array} \]
x\_m = (fabs.f64 x)
x\_s = (copysign.f64 #s(literal 1 binary64) x)
(FPCore (x_s x_m y z) :precision binary64 (* x_s (* (/ x_m z) y)))
x\_m = fabs(x);
x\_s = copysign(1.0, x);
double code(double x_s, double x_m, double y, double z) {
	return x_s * ((x_m / z) * y);
}
x\_m = abs(x)
x\_s = copysign(1.0d0, x)
real(8) function code(x_s, x_m, y, z)
    real(8), intent (in) :: x_s
    real(8), intent (in) :: x_m
    real(8), intent (in) :: y
    real(8), intent (in) :: z
    code = x_s * ((x_m / z) * y)
end function
x\_m = Math.abs(x);
x\_s = Math.copySign(1.0, x);
public static double code(double x_s, double x_m, double y, double z) {
	return x_s * ((x_m / z) * y);
}
x\_m = math.fabs(x)
x\_s = math.copysign(1.0, x)
def code(x_s, x_m, y, z):
	return x_s * ((x_m / z) * y)
x\_m = abs(x)
x\_s = copysign(1.0, x)
function code(x_s, x_m, y, z)
	return Float64(x_s * Float64(Float64(x_m / z) * y))
end
x\_m = abs(x);
x\_s = sign(x) * abs(1.0);
function tmp = code(x_s, x_m, y, z)
	tmp = x_s * ((x_m / z) * y);
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]
code[x$95$s_, x$95$m_, y_, z_] := N[(x$95$s * N[(N[(x$95$m / z), $MachinePrecision] * y), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
x\_m = \left|x\right|
\\
x\_s = \mathsf{copysign}\left(1, x\right)

\\
x\_s \cdot \left(\frac{x\_m}{z} \cdot y\right)
\end{array}
Derivation
  1. Initial program 85.3%

    \[\frac{x \cdot \left(y + z\right)}{z} \]
  2. Add Preprocessing
  3. Taylor expanded in x around 0

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

      \[\leadsto \color{blue}{x \cdot \frac{y + z}{z}} \]
    2. *-lft-identityN/A

      \[\leadsto x \cdot \frac{y + \color{blue}{1 \cdot z}}{z} \]
    3. metadata-evalN/A

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

      \[\leadsto x \cdot \frac{\color{blue}{y - -1 \cdot z}}{z} \]
    5. div-subN/A

      \[\leadsto x \cdot \color{blue}{\left(\frac{y}{z} - \frac{-1 \cdot z}{z}\right)} \]
    6. mul-1-negN/A

      \[\leadsto x \cdot \left(\frac{y}{z} - \frac{\color{blue}{\mathsf{neg}\left(z\right)}}{z}\right) \]
    7. distribute-frac-negN/A

      \[\leadsto x \cdot \left(\frac{y}{z} - \color{blue}{\left(\mathsf{neg}\left(\frac{z}{z}\right)\right)}\right) \]
    8. *-inversesN/A

      \[\leadsto x \cdot \left(\frac{y}{z} - \left(\mathsf{neg}\left(\color{blue}{1}\right)\right)\right) \]
    9. *-inversesN/A

      \[\leadsto x \cdot \left(\frac{y}{z} - \left(\mathsf{neg}\left(\color{blue}{\frac{y}{y}}\right)\right)\right) \]
    10. distribute-frac-negN/A

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

      \[\leadsto x \cdot \left(\frac{y}{z} - \frac{\color{blue}{-1 \cdot y}}{y}\right) \]
    12. distribute-rgt-out--N/A

      \[\leadsto \color{blue}{\frac{y}{z} \cdot x - \frac{-1 \cdot y}{y} \cdot x} \]
    13. *-commutativeN/A

      \[\leadsto \color{blue}{x \cdot \frac{y}{z}} - \frac{-1 \cdot y}{y} \cdot x \]
    14. associate-/l*N/A

      \[\leadsto \color{blue}{\frac{x \cdot y}{z}} - \frac{-1 \cdot y}{y} \cdot x \]
    15. associate-*l/N/A

      \[\leadsto \frac{x \cdot y}{z} - \color{blue}{\frac{\left(-1 \cdot y\right) \cdot x}{y}} \]
    16. associate-*r/N/A

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

      \[\leadsto \frac{x \cdot y}{z} - \color{blue}{\left(y \cdot -1\right)} \cdot \frac{x}{y} \]
    18. associate-*r*N/A

      \[\leadsto \frac{x \cdot y}{z} - \color{blue}{y \cdot \left(-1 \cdot \frac{x}{y}\right)} \]
    19. associate-*r*N/A

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

      \[\leadsto \frac{x \cdot y}{z} - \color{blue}{\left(-1 \cdot y\right)} \cdot \frac{x}{y} \]
    21. mul-1-negN/A

      \[\leadsto \frac{x \cdot y}{z} - \color{blue}{\left(\mathsf{neg}\left(y\right)\right)} \cdot \frac{x}{y} \]
    22. cancel-sign-subN/A

      \[\leadsto \color{blue}{\frac{x \cdot y}{z} + y \cdot \frac{x}{y}} \]
  5. Applied rewrites95.4%

    \[\leadsto \color{blue}{\mathsf{fma}\left(\frac{y}{z}, x, x\right)} \]
  6. Taylor expanded in y around inf

    \[\leadsto \color{blue}{\frac{x \cdot y}{z}} \]
  7. Step-by-step derivation
    1. associate-*l/N/A

      \[\leadsto \color{blue}{\frac{x}{z} \cdot y} \]
    2. lower-*.f64N/A

      \[\leadsto \color{blue}{\frac{x}{z} \cdot y} \]
    3. lower-/.f6450.9

      \[\leadsto \color{blue}{\frac{x}{z}} \cdot y \]
  8. Applied rewrites50.9%

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

Developer Target 1: 96.5% accurate, 0.8× speedup?

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

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

Reproduce

?
herbie shell --seed 2024340 
(FPCore (x y z)
  :name "Numeric.SpecFunctions:choose from math-functions-0.1.5.2"
  :precision binary64

  :alt
  (! :herbie-platform default (/ x (/ z (+ y z))))

  (/ (* x (+ y z)) z))