fabs fraction 1

Percentage Accurate: 91.6% → 99.7%
Time: 2.7s
Alternatives: 7
Speedup: 1.0×

Specification

?
\[\begin{array}{l} \\ \left|\frac{x + 4}{y} - \frac{x}{y} \cdot z\right| \end{array} \]
(FPCore (x y z) :precision binary64 (fabs (- (/ (+ x 4.0) y) (* (/ x y) z))))
double code(double x, double y, double z) {
	return fabs((((x + 4.0) / y) - ((x / y) * z)));
}
module fmin_fmax_functions
    implicit none
    private
    public fmax
    public fmin

    interface fmax
        module procedure fmax88
        module procedure fmax44
        module procedure fmax84
        module procedure fmax48
    end interface
    interface fmin
        module procedure fmin88
        module procedure fmin44
        module procedure fmin84
        module procedure fmin48
    end interface
contains
    real(8) function fmax88(x, y) result (res)
        real(8), intent (in) :: x
        real(8), intent (in) :: y
        res = merge(y, merge(x, max(x, y), y /= y), x /= x)
    end function
    real(4) function fmax44(x, y) result (res)
        real(4), intent (in) :: x
        real(4), intent (in) :: y
        res = merge(y, merge(x, max(x, y), y /= y), x /= x)
    end function
    real(8) function fmax84(x, y) result(res)
        real(8), intent (in) :: x
        real(4), intent (in) :: y
        res = merge(dble(y), merge(x, max(x, dble(y)), y /= y), x /= x)
    end function
    real(8) function fmax48(x, y) result(res)
        real(4), intent (in) :: x
        real(8), intent (in) :: y
        res = merge(y, merge(dble(x), max(dble(x), y), y /= y), x /= x)
    end function
    real(8) function fmin88(x, y) result (res)
        real(8), intent (in) :: x
        real(8), intent (in) :: y
        res = merge(y, merge(x, min(x, y), y /= y), x /= x)
    end function
    real(4) function fmin44(x, y) result (res)
        real(4), intent (in) :: x
        real(4), intent (in) :: y
        res = merge(y, merge(x, min(x, y), y /= y), x /= x)
    end function
    real(8) function fmin84(x, y) result(res)
        real(8), intent (in) :: x
        real(4), intent (in) :: y
        res = merge(dble(y), merge(x, min(x, dble(y)), y /= y), x /= x)
    end function
    real(8) function fmin48(x, y) result(res)
        real(4), intent (in) :: x
        real(8), intent (in) :: y
        res = merge(y, merge(dble(x), min(dble(x), y), y /= y), x /= x)
    end function
end module

real(8) function code(x, y, z)
use fmin_fmax_functions
    real(8), intent (in) :: x
    real(8), intent (in) :: y
    real(8), intent (in) :: z
    code = abs((((x + 4.0d0) / y) - ((x / y) * z)))
end function
public static double code(double x, double y, double z) {
	return Math.abs((((x + 4.0) / y) - ((x / y) * z)));
}
def code(x, y, z):
	return math.fabs((((x + 4.0) / y) - ((x / y) * z)))
function code(x, y, z)
	return abs(Float64(Float64(Float64(x + 4.0) / y) - Float64(Float64(x / y) * z)))
end
function tmp = code(x, y, z)
	tmp = abs((((x + 4.0) / y) - ((x / y) * z)));
end
code[x_, y_, z_] := N[Abs[N[(N[(N[(x + 4.0), $MachinePrecision] / y), $MachinePrecision] - N[(N[(x / y), $MachinePrecision] * z), $MachinePrecision]), $MachinePrecision]], $MachinePrecision]
\begin{array}{l}

\\
\left|\frac{x + 4}{y} - \frac{x}{y} \cdot z\right|
\end{array}

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: 91.6% accurate, 1.0× speedup?

\[\begin{array}{l} \\ \left|\frac{x + 4}{y} - \frac{x}{y} \cdot z\right| \end{array} \]
(FPCore (x y z) :precision binary64 (fabs (- (/ (+ x 4.0) y) (* (/ x y) z))))
double code(double x, double y, double z) {
	return fabs((((x + 4.0) / y) - ((x / y) * z)));
}
module fmin_fmax_functions
    implicit none
    private
    public fmax
    public fmin

    interface fmax
        module procedure fmax88
        module procedure fmax44
        module procedure fmax84
        module procedure fmax48
    end interface
    interface fmin
        module procedure fmin88
        module procedure fmin44
        module procedure fmin84
        module procedure fmin48
    end interface
contains
    real(8) function fmax88(x, y) result (res)
        real(8), intent (in) :: x
        real(8), intent (in) :: y
        res = merge(y, merge(x, max(x, y), y /= y), x /= x)
    end function
    real(4) function fmax44(x, y) result (res)
        real(4), intent (in) :: x
        real(4), intent (in) :: y
        res = merge(y, merge(x, max(x, y), y /= y), x /= x)
    end function
    real(8) function fmax84(x, y) result(res)
        real(8), intent (in) :: x
        real(4), intent (in) :: y
        res = merge(dble(y), merge(x, max(x, dble(y)), y /= y), x /= x)
    end function
    real(8) function fmax48(x, y) result(res)
        real(4), intent (in) :: x
        real(8), intent (in) :: y
        res = merge(y, merge(dble(x), max(dble(x), y), y /= y), x /= x)
    end function
    real(8) function fmin88(x, y) result (res)
        real(8), intent (in) :: x
        real(8), intent (in) :: y
        res = merge(y, merge(x, min(x, y), y /= y), x /= x)
    end function
    real(4) function fmin44(x, y) result (res)
        real(4), intent (in) :: x
        real(4), intent (in) :: y
        res = merge(y, merge(x, min(x, y), y /= y), x /= x)
    end function
    real(8) function fmin84(x, y) result(res)
        real(8), intent (in) :: x
        real(4), intent (in) :: y
        res = merge(dble(y), merge(x, min(x, dble(y)), y /= y), x /= x)
    end function
    real(8) function fmin48(x, y) result(res)
        real(4), intent (in) :: x
        real(8), intent (in) :: y
        res = merge(y, merge(dble(x), min(dble(x), y), y /= y), x /= x)
    end function
end module

real(8) function code(x, y, z)
use fmin_fmax_functions
    real(8), intent (in) :: x
    real(8), intent (in) :: y
    real(8), intent (in) :: z
    code = abs((((x + 4.0d0) / y) - ((x / y) * z)))
end function
public static double code(double x, double y, double z) {
	return Math.abs((((x + 4.0) / y) - ((x / y) * z)));
}
def code(x, y, z):
	return math.fabs((((x + 4.0) / y) - ((x / y) * z)))
function code(x, y, z)
	return abs(Float64(Float64(Float64(x + 4.0) / y) - Float64(Float64(x / y) * z)))
end
function tmp = code(x, y, z)
	tmp = abs((((x + 4.0) / y) - ((x / y) * z)));
end
code[x_, y_, z_] := N[Abs[N[(N[(N[(x + 4.0), $MachinePrecision] / y), $MachinePrecision] - N[(N[(x / y), $MachinePrecision] * z), $MachinePrecision]), $MachinePrecision]], $MachinePrecision]
\begin{array}{l}

\\
\left|\frac{x + 4}{y} - \frac{x}{y} \cdot z\right|
\end{array}

Alternative 1: 99.7% accurate, 0.8× speedup?

\[\begin{array}{l} y_m = \left|y\right| \\ \begin{array}{l} \mathbf{if}\;y\_m \leq 4 \cdot 10^{-55}:\\ \;\;\;\;\left|\frac{\mathsf{fma}\left(z, x, -4 - x\right)}{y\_m}\right|\\ \mathbf{else}:\\ \;\;\;\;\left|\mathsf{fma}\left(\frac{1 - z}{y\_m}, x, \frac{4}{y\_m}\right)\right|\\ \end{array} \end{array} \]
y_m = (fabs.f64 y)
(FPCore (x y_m z)
 :precision binary64
 (if (<= y_m 4e-55)
   (fabs (/ (fma z x (- -4.0 x)) y_m))
   (fabs (fma (/ (- 1.0 z) y_m) x (/ 4.0 y_m)))))
y_m = fabs(y);
double code(double x, double y_m, double z) {
	double tmp;
	if (y_m <= 4e-55) {
		tmp = fabs((fma(z, x, (-4.0 - x)) / y_m));
	} else {
		tmp = fabs(fma(((1.0 - z) / y_m), x, (4.0 / y_m)));
	}
	return tmp;
}
y_m = abs(y)
function code(x, y_m, z)
	tmp = 0.0
	if (y_m <= 4e-55)
		tmp = abs(Float64(fma(z, x, Float64(-4.0 - x)) / y_m));
	else
		tmp = abs(fma(Float64(Float64(1.0 - z) / y_m), x, Float64(4.0 / y_m)));
	end
	return tmp
end
y_m = N[Abs[y], $MachinePrecision]
code[x_, y$95$m_, z_] := If[LessEqual[y$95$m, 4e-55], N[Abs[N[(N[(z * x + N[(-4.0 - x), $MachinePrecision]), $MachinePrecision] / y$95$m), $MachinePrecision]], $MachinePrecision], N[Abs[N[(N[(N[(1.0 - z), $MachinePrecision] / y$95$m), $MachinePrecision] * x + N[(4.0 / y$95$m), $MachinePrecision]), $MachinePrecision]], $MachinePrecision]]
\begin{array}{l}
y_m = \left|y\right|

\\
\begin{array}{l}
\mathbf{if}\;y\_m \leq 4 \cdot 10^{-55}:\\
\;\;\;\;\left|\frac{\mathsf{fma}\left(z, x, -4 - x\right)}{y\_m}\right|\\

\mathbf{else}:\\
\;\;\;\;\left|\mathsf{fma}\left(\frac{1 - z}{y\_m}, x, \frac{4}{y\_m}\right)\right|\\


\end{array}
\end{array}
Derivation
  1. Split input into 2 regimes
  2. if y < 3.99999999999999998e-55

    1. Initial program 91.6%

      \[\left|\frac{x + 4}{y} - \frac{x}{y} \cdot z\right| \]
    2. Step-by-step derivation
      1. lift-fabs.f64N/A

        \[\leadsto \color{blue}{\left|\frac{x + 4}{y} - \frac{x}{y} \cdot z\right|} \]
      2. lift--.f64N/A

        \[\leadsto \left|\color{blue}{\frac{x + 4}{y} - \frac{x}{y} \cdot z}\right| \]
      3. lift-+.f64N/A

        \[\leadsto \left|\frac{\color{blue}{x + 4}}{y} - \frac{x}{y} \cdot z\right| \]
      4. lift-/.f64N/A

        \[\leadsto \left|\color{blue}{\frac{x + 4}{y}} - \frac{x}{y} \cdot z\right| \]
      5. lift-*.f64N/A

        \[\leadsto \left|\frac{x + 4}{y} - \color{blue}{\frac{x}{y} \cdot z}\right| \]
      6. lift-/.f64N/A

        \[\leadsto \left|\frac{x + 4}{y} - \color{blue}{\frac{x}{y}} \cdot z\right| \]
      7. neg-fabsN/A

        \[\leadsto \color{blue}{\left|\mathsf{neg}\left(\left(\frac{x + 4}{y} - \frac{x}{y} \cdot z\right)\right)\right|} \]
      8. lower-fabs.f64N/A

        \[\leadsto \color{blue}{\left|\mathsf{neg}\left(\left(\frac{x + 4}{y} - \frac{x}{y} \cdot z\right)\right)\right|} \]
      9. associate-*l/N/A

        \[\leadsto \left|\mathsf{neg}\left(\left(\frac{x + 4}{y} - \color{blue}{\frac{x \cdot z}{y}}\right)\right)\right| \]
      10. div-addN/A

        \[\leadsto \left|\mathsf{neg}\left(\left(\color{blue}{\left(\frac{x}{y} + \frac{4}{y}\right)} - \frac{x \cdot z}{y}\right)\right)\right| \]
      11. metadata-evalN/A

        \[\leadsto \left|\mathsf{neg}\left(\left(\left(\frac{x}{y} + \frac{\color{blue}{4 \cdot 1}}{y}\right) - \frac{x \cdot z}{y}\right)\right)\right| \]
      12. associate-*r/N/A

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

        \[\leadsto \left|\mathsf{neg}\left(\left(\color{blue}{\left(4 \cdot \frac{1}{y} + \frac{x}{y}\right)} - \frac{x \cdot z}{y}\right)\right)\right| \]
      14. associate-*r/N/A

        \[\leadsto \left|\mathsf{neg}\left(\left(\left(\color{blue}{\frac{4 \cdot 1}{y}} + \frac{x}{y}\right) - \frac{x \cdot z}{y}\right)\right)\right| \]
      15. metadata-evalN/A

        \[\leadsto \left|\mathsf{neg}\left(\left(\left(\frac{\color{blue}{4}}{y} + \frac{x}{y}\right) - \frac{x \cdot z}{y}\right)\right)\right| \]
      16. div-addN/A

        \[\leadsto \left|\mathsf{neg}\left(\left(\color{blue}{\frac{4 + x}{y}} - \frac{x \cdot z}{y}\right)\right)\right| \]
      17. div-subN/A

        \[\leadsto \left|\mathsf{neg}\left(\color{blue}{\frac{\left(4 + x\right) - x \cdot z}{y}}\right)\right| \]
    3. Applied rewrites95.9%

      \[\leadsto \color{blue}{\left|\frac{\mathsf{fma}\left(z, x, -4 - x\right)}{y}\right|} \]

    if 3.99999999999999998e-55 < y

    1. Initial program 91.6%

      \[\left|\frac{x + 4}{y} - \frac{x}{y} \cdot z\right| \]
    2. Applied rewrites95.8%

      \[\leadsto \left|\color{blue}{\mathsf{fma}\left(\frac{1 - z}{y}, x, \frac{4}{y}\right)}\right| \]
  3. Recombined 2 regimes into one program.
  4. Add Preprocessing

Alternative 2: 98.8% accurate, 1.0× speedup?

\[\begin{array}{l} y_m = \left|y\right| \\ \begin{array}{l} \mathbf{if}\;x \leq -6 \cdot 10^{+234}:\\ \;\;\;\;\left|\frac{1 - z}{y\_m} \cdot x\right|\\ \mathbf{else}:\\ \;\;\;\;\left|\frac{\mathsf{fma}\left(z, x, -4 - x\right)}{y\_m}\right|\\ \end{array} \end{array} \]
y_m = (fabs.f64 y)
(FPCore (x y_m z)
 :precision binary64
 (if (<= x -6e+234)
   (fabs (* (/ (- 1.0 z) y_m) x))
   (fabs (/ (fma z x (- -4.0 x)) y_m))))
y_m = fabs(y);
double code(double x, double y_m, double z) {
	double tmp;
	if (x <= -6e+234) {
		tmp = fabs((((1.0 - z) / y_m) * x));
	} else {
		tmp = fabs((fma(z, x, (-4.0 - x)) / y_m));
	}
	return tmp;
}
y_m = abs(y)
function code(x, y_m, z)
	tmp = 0.0
	if (x <= -6e+234)
		tmp = abs(Float64(Float64(Float64(1.0 - z) / y_m) * x));
	else
		tmp = abs(Float64(fma(z, x, Float64(-4.0 - x)) / y_m));
	end
	return tmp
end
y_m = N[Abs[y], $MachinePrecision]
code[x_, y$95$m_, z_] := If[LessEqual[x, -6e+234], N[Abs[N[(N[(N[(1.0 - z), $MachinePrecision] / y$95$m), $MachinePrecision] * x), $MachinePrecision]], $MachinePrecision], N[Abs[N[(N[(z * x + N[(-4.0 - x), $MachinePrecision]), $MachinePrecision] / y$95$m), $MachinePrecision]], $MachinePrecision]]
\begin{array}{l}
y_m = \left|y\right|

\\
\begin{array}{l}
\mathbf{if}\;x \leq -6 \cdot 10^{+234}:\\
\;\;\;\;\left|\frac{1 - z}{y\_m} \cdot x\right|\\

\mathbf{else}:\\
\;\;\;\;\left|\frac{\mathsf{fma}\left(z, x, -4 - x\right)}{y\_m}\right|\\


\end{array}
\end{array}
Derivation
  1. Split input into 2 regimes
  2. if x < -5.9999999999999998e234

    1. Initial program 91.6%

      \[\left|\frac{x + 4}{y} - \frac{x}{y} \cdot z\right| \]
    2. Taylor expanded in x around inf

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

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

        \[\leadsto \left|\left(\frac{1}{y} - \frac{z}{y}\right) \cdot \color{blue}{x}\right| \]
      3. sub-divN/A

        \[\leadsto \left|\frac{1 - z}{y} \cdot x\right| \]
      4. lower-/.f64N/A

        \[\leadsto \left|\frac{1 - z}{y} \cdot x\right| \]
      5. lower--.f6461.1

        \[\leadsto \left|\frac{1 - z}{y} \cdot x\right| \]
    4. Applied rewrites61.1%

      \[\leadsto \left|\color{blue}{\frac{1 - z}{y} \cdot x}\right| \]

    if -5.9999999999999998e234 < x

    1. Initial program 91.6%

      \[\left|\frac{x + 4}{y} - \frac{x}{y} \cdot z\right| \]
    2. Step-by-step derivation
      1. lift-fabs.f64N/A

        \[\leadsto \color{blue}{\left|\frac{x + 4}{y} - \frac{x}{y} \cdot z\right|} \]
      2. lift--.f64N/A

        \[\leadsto \left|\color{blue}{\frac{x + 4}{y} - \frac{x}{y} \cdot z}\right| \]
      3. lift-+.f64N/A

        \[\leadsto \left|\frac{\color{blue}{x + 4}}{y} - \frac{x}{y} \cdot z\right| \]
      4. lift-/.f64N/A

        \[\leadsto \left|\color{blue}{\frac{x + 4}{y}} - \frac{x}{y} \cdot z\right| \]
      5. lift-*.f64N/A

        \[\leadsto \left|\frac{x + 4}{y} - \color{blue}{\frac{x}{y} \cdot z}\right| \]
      6. lift-/.f64N/A

        \[\leadsto \left|\frac{x + 4}{y} - \color{blue}{\frac{x}{y}} \cdot z\right| \]
      7. neg-fabsN/A

        \[\leadsto \color{blue}{\left|\mathsf{neg}\left(\left(\frac{x + 4}{y} - \frac{x}{y} \cdot z\right)\right)\right|} \]
      8. lower-fabs.f64N/A

        \[\leadsto \color{blue}{\left|\mathsf{neg}\left(\left(\frac{x + 4}{y} - \frac{x}{y} \cdot z\right)\right)\right|} \]
      9. associate-*l/N/A

        \[\leadsto \left|\mathsf{neg}\left(\left(\frac{x + 4}{y} - \color{blue}{\frac{x \cdot z}{y}}\right)\right)\right| \]
      10. div-addN/A

        \[\leadsto \left|\mathsf{neg}\left(\left(\color{blue}{\left(\frac{x}{y} + \frac{4}{y}\right)} - \frac{x \cdot z}{y}\right)\right)\right| \]
      11. metadata-evalN/A

        \[\leadsto \left|\mathsf{neg}\left(\left(\left(\frac{x}{y} + \frac{\color{blue}{4 \cdot 1}}{y}\right) - \frac{x \cdot z}{y}\right)\right)\right| \]
      12. associate-*r/N/A

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

        \[\leadsto \left|\mathsf{neg}\left(\left(\color{blue}{\left(4 \cdot \frac{1}{y} + \frac{x}{y}\right)} - \frac{x \cdot z}{y}\right)\right)\right| \]
      14. associate-*r/N/A

        \[\leadsto \left|\mathsf{neg}\left(\left(\left(\color{blue}{\frac{4 \cdot 1}{y}} + \frac{x}{y}\right) - \frac{x \cdot z}{y}\right)\right)\right| \]
      15. metadata-evalN/A

        \[\leadsto \left|\mathsf{neg}\left(\left(\left(\frac{\color{blue}{4}}{y} + \frac{x}{y}\right) - \frac{x \cdot z}{y}\right)\right)\right| \]
      16. div-addN/A

        \[\leadsto \left|\mathsf{neg}\left(\left(\color{blue}{\frac{4 + x}{y}} - \frac{x \cdot z}{y}\right)\right)\right| \]
      17. div-subN/A

        \[\leadsto \left|\mathsf{neg}\left(\color{blue}{\frac{\left(4 + x\right) - x \cdot z}{y}}\right)\right| \]
    3. Applied rewrites95.9%

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

Alternative 3: 96.7% accurate, 0.9× speedup?

\[\begin{array}{l} y_m = \left|y\right| \\ \begin{array}{l} t_0 := \left|\frac{1 - z}{y\_m} \cdot x\right|\\ \mathbf{if}\;x \leq -1.55:\\ \;\;\;\;t\_0\\ \mathbf{elif}\;x \leq 4:\\ \;\;\;\;\left|\frac{4 - z \cdot x}{y\_m}\right|\\ \mathbf{else}:\\ \;\;\;\;t\_0\\ \end{array} \end{array} \]
y_m = (fabs.f64 y)
(FPCore (x y_m z)
 :precision binary64
 (let* ((t_0 (fabs (* (/ (- 1.0 z) y_m) x))))
   (if (<= x -1.55) t_0 (if (<= x 4.0) (fabs (/ (- 4.0 (* z x)) y_m)) t_0))))
y_m = fabs(y);
double code(double x, double y_m, double z) {
	double t_0 = fabs((((1.0 - z) / y_m) * x));
	double tmp;
	if (x <= -1.55) {
		tmp = t_0;
	} else if (x <= 4.0) {
		tmp = fabs(((4.0 - (z * x)) / y_m));
	} else {
		tmp = t_0;
	}
	return tmp;
}
y_m =     private
module fmin_fmax_functions
    implicit none
    private
    public fmax
    public fmin

    interface fmax
        module procedure fmax88
        module procedure fmax44
        module procedure fmax84
        module procedure fmax48
    end interface
    interface fmin
        module procedure fmin88
        module procedure fmin44
        module procedure fmin84
        module procedure fmin48
    end interface
contains
    real(8) function fmax88(x, y) result (res)
        real(8), intent (in) :: x
        real(8), intent (in) :: y
        res = merge(y, merge(x, max(x, y), y /= y), x /= x)
    end function
    real(4) function fmax44(x, y) result (res)
        real(4), intent (in) :: x
        real(4), intent (in) :: y
        res = merge(y, merge(x, max(x, y), y /= y), x /= x)
    end function
    real(8) function fmax84(x, y) result(res)
        real(8), intent (in) :: x
        real(4), intent (in) :: y
        res = merge(dble(y), merge(x, max(x, dble(y)), y /= y), x /= x)
    end function
    real(8) function fmax48(x, y) result(res)
        real(4), intent (in) :: x
        real(8), intent (in) :: y
        res = merge(y, merge(dble(x), max(dble(x), y), y /= y), x /= x)
    end function
    real(8) function fmin88(x, y) result (res)
        real(8), intent (in) :: x
        real(8), intent (in) :: y
        res = merge(y, merge(x, min(x, y), y /= y), x /= x)
    end function
    real(4) function fmin44(x, y) result (res)
        real(4), intent (in) :: x
        real(4), intent (in) :: y
        res = merge(y, merge(x, min(x, y), y /= y), x /= x)
    end function
    real(8) function fmin84(x, y) result(res)
        real(8), intent (in) :: x
        real(4), intent (in) :: y
        res = merge(dble(y), merge(x, min(x, dble(y)), y /= y), x /= x)
    end function
    real(8) function fmin48(x, y) result(res)
        real(4), intent (in) :: x
        real(8), intent (in) :: y
        res = merge(y, merge(dble(x), min(dble(x), y), y /= y), x /= x)
    end function
end module

real(8) function code(x, y_m, z)
use fmin_fmax_functions
    real(8), intent (in) :: x
    real(8), intent (in) :: y_m
    real(8), intent (in) :: z
    real(8) :: t_0
    real(8) :: tmp
    t_0 = abs((((1.0d0 - z) / y_m) * x))
    if (x <= (-1.55d0)) then
        tmp = t_0
    else if (x <= 4.0d0) then
        tmp = abs(((4.0d0 - (z * x)) / y_m))
    else
        tmp = t_0
    end if
    code = tmp
end function
y_m = Math.abs(y);
public static double code(double x, double y_m, double z) {
	double t_0 = Math.abs((((1.0 - z) / y_m) * x));
	double tmp;
	if (x <= -1.55) {
		tmp = t_0;
	} else if (x <= 4.0) {
		tmp = Math.abs(((4.0 - (z * x)) / y_m));
	} else {
		tmp = t_0;
	}
	return tmp;
}
y_m = math.fabs(y)
def code(x, y_m, z):
	t_0 = math.fabs((((1.0 - z) / y_m) * x))
	tmp = 0
	if x <= -1.55:
		tmp = t_0
	elif x <= 4.0:
		tmp = math.fabs(((4.0 - (z * x)) / y_m))
	else:
		tmp = t_0
	return tmp
y_m = abs(y)
function code(x, y_m, z)
	t_0 = abs(Float64(Float64(Float64(1.0 - z) / y_m) * x))
	tmp = 0.0
	if (x <= -1.55)
		tmp = t_0;
	elseif (x <= 4.0)
		tmp = abs(Float64(Float64(4.0 - Float64(z * x)) / y_m));
	else
		tmp = t_0;
	end
	return tmp
end
y_m = abs(y);
function tmp_2 = code(x, y_m, z)
	t_0 = abs((((1.0 - z) / y_m) * x));
	tmp = 0.0;
	if (x <= -1.55)
		tmp = t_0;
	elseif (x <= 4.0)
		tmp = abs(((4.0 - (z * x)) / y_m));
	else
		tmp = t_0;
	end
	tmp_2 = tmp;
end
y_m = N[Abs[y], $MachinePrecision]
code[x_, y$95$m_, z_] := Block[{t$95$0 = N[Abs[N[(N[(N[(1.0 - z), $MachinePrecision] / y$95$m), $MachinePrecision] * x), $MachinePrecision]], $MachinePrecision]}, If[LessEqual[x, -1.55], t$95$0, If[LessEqual[x, 4.0], N[Abs[N[(N[(4.0 - N[(z * x), $MachinePrecision]), $MachinePrecision] / y$95$m), $MachinePrecision]], $MachinePrecision], t$95$0]]]
\begin{array}{l}
y_m = \left|y\right|

\\
\begin{array}{l}
t_0 := \left|\frac{1 - z}{y\_m} \cdot x\right|\\
\mathbf{if}\;x \leq -1.55:\\
\;\;\;\;t\_0\\

\mathbf{elif}\;x \leq 4:\\
\;\;\;\;\left|\frac{4 - z \cdot x}{y\_m}\right|\\

\mathbf{else}:\\
\;\;\;\;t\_0\\


\end{array}
\end{array}
Derivation
  1. Split input into 2 regimes
  2. if x < -1.55000000000000004 or 4 < x

    1. Initial program 91.6%

      \[\left|\frac{x + 4}{y} - \frac{x}{y} \cdot z\right| \]
    2. Taylor expanded in x around inf

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

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

        \[\leadsto \left|\left(\frac{1}{y} - \frac{z}{y}\right) \cdot \color{blue}{x}\right| \]
      3. sub-divN/A

        \[\leadsto \left|\frac{1 - z}{y} \cdot x\right| \]
      4. lower-/.f64N/A

        \[\leadsto \left|\frac{1 - z}{y} \cdot x\right| \]
      5. lower--.f6461.1

        \[\leadsto \left|\frac{1 - z}{y} \cdot x\right| \]
    4. Applied rewrites61.1%

      \[\leadsto \left|\color{blue}{\frac{1 - z}{y} \cdot x}\right| \]

    if -1.55000000000000004 < x < 4

    1. Initial program 91.6%

      \[\left|\frac{x + 4}{y} - \frac{x}{y} \cdot z\right| \]
    2. Step-by-step derivation
      1. lift--.f64N/A

        \[\leadsto \left|\color{blue}{\frac{x + 4}{y} - \frac{x}{y} \cdot z}\right| \]
      2. lift-+.f64N/A

        \[\leadsto \left|\frac{\color{blue}{x + 4}}{y} - \frac{x}{y} \cdot z\right| \]
      3. lift-/.f64N/A

        \[\leadsto \left|\color{blue}{\frac{x + 4}{y}} - \frac{x}{y} \cdot z\right| \]
      4. lift-*.f64N/A

        \[\leadsto \left|\frac{x + 4}{y} - \color{blue}{\frac{x}{y} \cdot z}\right| \]
      5. lift-/.f64N/A

        \[\leadsto \left|\frac{x + 4}{y} - \color{blue}{\frac{x}{y}} \cdot z\right| \]
      6. associate-*l/N/A

        \[\leadsto \left|\frac{x + 4}{y} - \color{blue}{\frac{x \cdot z}{y}}\right| \]
      7. +-commutativeN/A

        \[\leadsto \left|\frac{\color{blue}{4 + x}}{y} - \frac{x \cdot z}{y}\right| \]
      8. div-subN/A

        \[\leadsto \left|\color{blue}{\frac{\left(4 + x\right) - x \cdot z}{y}}\right| \]
      9. lower-/.f64N/A

        \[\leadsto \left|\color{blue}{\frac{\left(4 + x\right) - x \cdot z}{y}}\right| \]
      10. lower--.f64N/A

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

        \[\leadsto \left|\frac{\color{blue}{\left(x + 4\right)} - x \cdot z}{y}\right| \]
      12. metadata-evalN/A

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

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

        \[\leadsto \left|\frac{\left(x - \color{blue}{\left(\mathsf{neg}\left(4 \cdot 1\right)\right)}\right) - x \cdot z}{y}\right| \]
      15. metadata-evalN/A

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

        \[\leadsto \left|\frac{\color{blue}{\left(x - \left(\mathsf{neg}\left(4\right)\right)\right)} - x \cdot z}{y}\right| \]
      17. metadata-evalN/A

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

        \[\leadsto \left|\frac{\left(x - -4\right) - \color{blue}{z \cdot x}}{y}\right| \]
      19. lower-*.f6495.9

        \[\leadsto \left|\frac{\left(x - -4\right) - \color{blue}{z \cdot x}}{y}\right| \]
    3. Applied rewrites95.9%

      \[\leadsto \left|\color{blue}{\frac{\left(x - -4\right) - z \cdot x}{y}}\right| \]
    4. Taylor expanded in x around 0

      \[\leadsto \left|\frac{\color{blue}{4} - z \cdot x}{y}\right| \]
    5. Step-by-step derivation
      1. metadata-eval74.5

        \[\leadsto \left|\frac{4 - z \cdot x}{y}\right| \]
      2. fp-cancel-sub-sign-inv74.5

        \[\leadsto \left|\frac{4 - z \cdot x}{y}\right| \]
      3. metadata-eval74.5

        \[\leadsto \left|\frac{4 - z \cdot x}{y}\right| \]
      4. metadata-eval74.5

        \[\leadsto \left|\frac{4 - z \cdot x}{y}\right| \]
    6. Applied rewrites74.5%

      \[\leadsto \left|\frac{\color{blue}{4} - z \cdot x}{y}\right| \]
  3. Recombined 2 regimes into one program.
  4. Add Preprocessing

Alternative 4: 85.9% accurate, 1.0× speedup?

\[\begin{array}{l} y_m = \left|y\right| \\ \begin{array}{l} t_0 := \left|\left(-z\right) \cdot \frac{x}{y\_m}\right|\\ \mathbf{if}\;z \leq -6.6 \cdot 10^{+31}:\\ \;\;\;\;t\_0\\ \mathbf{elif}\;z \leq 2.9 \cdot 10^{+67}:\\ \;\;\;\;\left|\frac{x - -4}{y\_m}\right|\\ \mathbf{else}:\\ \;\;\;\;t\_0\\ \end{array} \end{array} \]
y_m = (fabs.f64 y)
(FPCore (x y_m z)
 :precision binary64
 (let* ((t_0 (fabs (* (- z) (/ x y_m)))))
   (if (<= z -6.6e+31) t_0 (if (<= z 2.9e+67) (fabs (/ (- x -4.0) y_m)) t_0))))
y_m = fabs(y);
double code(double x, double y_m, double z) {
	double t_0 = fabs((-z * (x / y_m)));
	double tmp;
	if (z <= -6.6e+31) {
		tmp = t_0;
	} else if (z <= 2.9e+67) {
		tmp = fabs(((x - -4.0) / y_m));
	} else {
		tmp = t_0;
	}
	return tmp;
}
y_m =     private
module fmin_fmax_functions
    implicit none
    private
    public fmax
    public fmin

    interface fmax
        module procedure fmax88
        module procedure fmax44
        module procedure fmax84
        module procedure fmax48
    end interface
    interface fmin
        module procedure fmin88
        module procedure fmin44
        module procedure fmin84
        module procedure fmin48
    end interface
contains
    real(8) function fmax88(x, y) result (res)
        real(8), intent (in) :: x
        real(8), intent (in) :: y
        res = merge(y, merge(x, max(x, y), y /= y), x /= x)
    end function
    real(4) function fmax44(x, y) result (res)
        real(4), intent (in) :: x
        real(4), intent (in) :: y
        res = merge(y, merge(x, max(x, y), y /= y), x /= x)
    end function
    real(8) function fmax84(x, y) result(res)
        real(8), intent (in) :: x
        real(4), intent (in) :: y
        res = merge(dble(y), merge(x, max(x, dble(y)), y /= y), x /= x)
    end function
    real(8) function fmax48(x, y) result(res)
        real(4), intent (in) :: x
        real(8), intent (in) :: y
        res = merge(y, merge(dble(x), max(dble(x), y), y /= y), x /= x)
    end function
    real(8) function fmin88(x, y) result (res)
        real(8), intent (in) :: x
        real(8), intent (in) :: y
        res = merge(y, merge(x, min(x, y), y /= y), x /= x)
    end function
    real(4) function fmin44(x, y) result (res)
        real(4), intent (in) :: x
        real(4), intent (in) :: y
        res = merge(y, merge(x, min(x, y), y /= y), x /= x)
    end function
    real(8) function fmin84(x, y) result(res)
        real(8), intent (in) :: x
        real(4), intent (in) :: y
        res = merge(dble(y), merge(x, min(x, dble(y)), y /= y), x /= x)
    end function
    real(8) function fmin48(x, y) result(res)
        real(4), intent (in) :: x
        real(8), intent (in) :: y
        res = merge(y, merge(dble(x), min(dble(x), y), y /= y), x /= x)
    end function
end module

real(8) function code(x, y_m, z)
use fmin_fmax_functions
    real(8), intent (in) :: x
    real(8), intent (in) :: y_m
    real(8), intent (in) :: z
    real(8) :: t_0
    real(8) :: tmp
    t_0 = abs((-z * (x / y_m)))
    if (z <= (-6.6d+31)) then
        tmp = t_0
    else if (z <= 2.9d+67) then
        tmp = abs(((x - (-4.0d0)) / y_m))
    else
        tmp = t_0
    end if
    code = tmp
end function
y_m = Math.abs(y);
public static double code(double x, double y_m, double z) {
	double t_0 = Math.abs((-z * (x / y_m)));
	double tmp;
	if (z <= -6.6e+31) {
		tmp = t_0;
	} else if (z <= 2.9e+67) {
		tmp = Math.abs(((x - -4.0) / y_m));
	} else {
		tmp = t_0;
	}
	return tmp;
}
y_m = math.fabs(y)
def code(x, y_m, z):
	t_0 = math.fabs((-z * (x / y_m)))
	tmp = 0
	if z <= -6.6e+31:
		tmp = t_0
	elif z <= 2.9e+67:
		tmp = math.fabs(((x - -4.0) / y_m))
	else:
		tmp = t_0
	return tmp
y_m = abs(y)
function code(x, y_m, z)
	t_0 = abs(Float64(Float64(-z) * Float64(x / y_m)))
	tmp = 0.0
	if (z <= -6.6e+31)
		tmp = t_0;
	elseif (z <= 2.9e+67)
		tmp = abs(Float64(Float64(x - -4.0) / y_m));
	else
		tmp = t_0;
	end
	return tmp
end
y_m = abs(y);
function tmp_2 = code(x, y_m, z)
	t_0 = abs((-z * (x / y_m)));
	tmp = 0.0;
	if (z <= -6.6e+31)
		tmp = t_0;
	elseif (z <= 2.9e+67)
		tmp = abs(((x - -4.0) / y_m));
	else
		tmp = t_0;
	end
	tmp_2 = tmp;
end
y_m = N[Abs[y], $MachinePrecision]
code[x_, y$95$m_, z_] := Block[{t$95$0 = N[Abs[N[((-z) * N[(x / y$95$m), $MachinePrecision]), $MachinePrecision]], $MachinePrecision]}, If[LessEqual[z, -6.6e+31], t$95$0, If[LessEqual[z, 2.9e+67], N[Abs[N[(N[(x - -4.0), $MachinePrecision] / y$95$m), $MachinePrecision]], $MachinePrecision], t$95$0]]]
\begin{array}{l}
y_m = \left|y\right|

\\
\begin{array}{l}
t_0 := \left|\left(-z\right) \cdot \frac{x}{y\_m}\right|\\
\mathbf{if}\;z \leq -6.6 \cdot 10^{+31}:\\
\;\;\;\;t\_0\\

\mathbf{elif}\;z \leq 2.9 \cdot 10^{+67}:\\
\;\;\;\;\left|\frac{x - -4}{y\_m}\right|\\

\mathbf{else}:\\
\;\;\;\;t\_0\\


\end{array}
\end{array}
Derivation
  1. Split input into 2 regimes
  2. if z < -6.59999999999999985e31 or 2.90000000000000023e67 < z

    1. Initial program 91.6%

      \[\left|\frac{x + 4}{y} - \frac{x}{y} \cdot z\right| \]
    2. Taylor expanded in z around inf

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

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

        \[\leadsto \left|\mathsf{neg}\left(\frac{x}{y} \cdot z\right)\right| \]
      3. *-commutativeN/A

        \[\leadsto \left|\mathsf{neg}\left(z \cdot \frac{x}{y}\right)\right| \]
      4. distribute-lft-neg-inN/A

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

        \[\leadsto \left|\left(\mathsf{neg}\left(z\right)\right) \cdot \color{blue}{\frac{x}{y}}\right| \]
      6. lower-neg.f64N/A

        \[\leadsto \left|\left(-z\right) \cdot \frac{\color{blue}{x}}{y}\right| \]
      7. lift-/.f6444.2

        \[\leadsto \left|\left(-z\right) \cdot \frac{x}{\color{blue}{y}}\right| \]
    4. Applied rewrites44.2%

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

    if -6.59999999999999985e31 < z < 2.90000000000000023e67

    1. Initial program 91.6%

      \[\left|\frac{x + 4}{y} - \frac{x}{y} \cdot z\right| \]
    2. Taylor expanded in z around 0

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

        \[\leadsto \left|\frac{4 \cdot 1}{y} + \frac{\color{blue}{x}}{y}\right| \]
      2. metadata-evalN/A

        \[\leadsto \left|\frac{4}{y} + \frac{x}{y}\right| \]
      3. div-addN/A

        \[\leadsto \left|\frac{4 + x}{\color{blue}{y}}\right| \]
      4. lower-/.f64N/A

        \[\leadsto \left|\frac{4 + x}{\color{blue}{y}}\right| \]
      5. +-commutativeN/A

        \[\leadsto \left|\frac{x + 4}{y}\right| \]
      6. metadata-evalN/A

        \[\leadsto \left|\frac{x + 4 \cdot 1}{y}\right| \]
      7. fp-cancel-sign-sub-invN/A

        \[\leadsto \left|\frac{x - \left(\mathsf{neg}\left(4\right)\right) \cdot 1}{y}\right| \]
      8. distribute-lft-neg-inN/A

        \[\leadsto \left|\frac{x - \left(\mathsf{neg}\left(4 \cdot 1\right)\right)}{y}\right| \]
      9. metadata-evalN/A

        \[\leadsto \left|\frac{x - \left(\mathsf{neg}\left(4\right)\right)}{y}\right| \]
      10. lower--.f64N/A

        \[\leadsto \left|\frac{x - \left(\mathsf{neg}\left(4\right)\right)}{y}\right| \]
      11. metadata-eval70.0

        \[\leadsto \left|\frac{x - -4}{y}\right| \]
    4. Applied rewrites70.0%

      \[\leadsto \left|\color{blue}{\frac{x - -4}{y}}\right| \]
  3. Recombined 2 regimes into one program.
  4. Add Preprocessing

Alternative 5: 70.0% accurate, 2.1× speedup?

\[\begin{array}{l} y_m = \left|y\right| \\ \left|\frac{x - -4}{y\_m}\right| \end{array} \]
y_m = (fabs.f64 y)
(FPCore (x y_m z) :precision binary64 (fabs (/ (- x -4.0) y_m)))
y_m = fabs(y);
double code(double x, double y_m, double z) {
	return fabs(((x - -4.0) / y_m));
}
y_m =     private
module fmin_fmax_functions
    implicit none
    private
    public fmax
    public fmin

    interface fmax
        module procedure fmax88
        module procedure fmax44
        module procedure fmax84
        module procedure fmax48
    end interface
    interface fmin
        module procedure fmin88
        module procedure fmin44
        module procedure fmin84
        module procedure fmin48
    end interface
contains
    real(8) function fmax88(x, y) result (res)
        real(8), intent (in) :: x
        real(8), intent (in) :: y
        res = merge(y, merge(x, max(x, y), y /= y), x /= x)
    end function
    real(4) function fmax44(x, y) result (res)
        real(4), intent (in) :: x
        real(4), intent (in) :: y
        res = merge(y, merge(x, max(x, y), y /= y), x /= x)
    end function
    real(8) function fmax84(x, y) result(res)
        real(8), intent (in) :: x
        real(4), intent (in) :: y
        res = merge(dble(y), merge(x, max(x, dble(y)), y /= y), x /= x)
    end function
    real(8) function fmax48(x, y) result(res)
        real(4), intent (in) :: x
        real(8), intent (in) :: y
        res = merge(y, merge(dble(x), max(dble(x), y), y /= y), x /= x)
    end function
    real(8) function fmin88(x, y) result (res)
        real(8), intent (in) :: x
        real(8), intent (in) :: y
        res = merge(y, merge(x, min(x, y), y /= y), x /= x)
    end function
    real(4) function fmin44(x, y) result (res)
        real(4), intent (in) :: x
        real(4), intent (in) :: y
        res = merge(y, merge(x, min(x, y), y /= y), x /= x)
    end function
    real(8) function fmin84(x, y) result(res)
        real(8), intent (in) :: x
        real(4), intent (in) :: y
        res = merge(dble(y), merge(x, min(x, dble(y)), y /= y), x /= x)
    end function
    real(8) function fmin48(x, y) result(res)
        real(4), intent (in) :: x
        real(8), intent (in) :: y
        res = merge(y, merge(dble(x), min(dble(x), y), y /= y), x /= x)
    end function
end module

real(8) function code(x, y_m, z)
use fmin_fmax_functions
    real(8), intent (in) :: x
    real(8), intent (in) :: y_m
    real(8), intent (in) :: z
    code = abs(((x - (-4.0d0)) / y_m))
end function
y_m = Math.abs(y);
public static double code(double x, double y_m, double z) {
	return Math.abs(((x - -4.0) / y_m));
}
y_m = math.fabs(y)
def code(x, y_m, z):
	return math.fabs(((x - -4.0) / y_m))
y_m = abs(y)
function code(x, y_m, z)
	return abs(Float64(Float64(x - -4.0) / y_m))
end
y_m = abs(y);
function tmp = code(x, y_m, z)
	tmp = abs(((x - -4.0) / y_m));
end
y_m = N[Abs[y], $MachinePrecision]
code[x_, y$95$m_, z_] := N[Abs[N[(N[(x - -4.0), $MachinePrecision] / y$95$m), $MachinePrecision]], $MachinePrecision]
\begin{array}{l}
y_m = \left|y\right|

\\
\left|\frac{x - -4}{y\_m}\right|
\end{array}
Derivation
  1. Initial program 91.6%

    \[\left|\frac{x + 4}{y} - \frac{x}{y} \cdot z\right| \]
  2. Taylor expanded in z around 0

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

      \[\leadsto \left|\frac{4 \cdot 1}{y} + \frac{\color{blue}{x}}{y}\right| \]
    2. metadata-evalN/A

      \[\leadsto \left|\frac{4}{y} + \frac{x}{y}\right| \]
    3. div-addN/A

      \[\leadsto \left|\frac{4 + x}{\color{blue}{y}}\right| \]
    4. lower-/.f64N/A

      \[\leadsto \left|\frac{4 + x}{\color{blue}{y}}\right| \]
    5. +-commutativeN/A

      \[\leadsto \left|\frac{x + 4}{y}\right| \]
    6. metadata-evalN/A

      \[\leadsto \left|\frac{x + 4 \cdot 1}{y}\right| \]
    7. fp-cancel-sign-sub-invN/A

      \[\leadsto \left|\frac{x - \left(\mathsf{neg}\left(4\right)\right) \cdot 1}{y}\right| \]
    8. distribute-lft-neg-inN/A

      \[\leadsto \left|\frac{x - \left(\mathsf{neg}\left(4 \cdot 1\right)\right)}{y}\right| \]
    9. metadata-evalN/A

      \[\leadsto \left|\frac{x - \left(\mathsf{neg}\left(4\right)\right)}{y}\right| \]
    10. lower--.f64N/A

      \[\leadsto \left|\frac{x - \left(\mathsf{neg}\left(4\right)\right)}{y}\right| \]
    11. metadata-eval70.0

      \[\leadsto \left|\frac{x - -4}{y}\right| \]
  4. Applied rewrites70.0%

    \[\leadsto \left|\color{blue}{\frac{x - -4}{y}}\right| \]
  5. Add Preprocessing

Alternative 6: 69.0% accurate, 1.3× speedup?

\[\begin{array}{l} y_m = \left|y\right| \\ \begin{array}{l} t_0 := \left|\frac{x}{y\_m}\right|\\ \mathbf{if}\;x \leq -1.52:\\ \;\;\;\;t\_0\\ \mathbf{elif}\;x \leq 4:\\ \;\;\;\;\left|\frac{4}{y\_m}\right|\\ \mathbf{else}:\\ \;\;\;\;t\_0\\ \end{array} \end{array} \]
y_m = (fabs.f64 y)
(FPCore (x y_m z)
 :precision binary64
 (let* ((t_0 (fabs (/ x y_m))))
   (if (<= x -1.52) t_0 (if (<= x 4.0) (fabs (/ 4.0 y_m)) t_0))))
y_m = fabs(y);
double code(double x, double y_m, double z) {
	double t_0 = fabs((x / y_m));
	double tmp;
	if (x <= -1.52) {
		tmp = t_0;
	} else if (x <= 4.0) {
		tmp = fabs((4.0 / y_m));
	} else {
		tmp = t_0;
	}
	return tmp;
}
y_m =     private
module fmin_fmax_functions
    implicit none
    private
    public fmax
    public fmin

    interface fmax
        module procedure fmax88
        module procedure fmax44
        module procedure fmax84
        module procedure fmax48
    end interface
    interface fmin
        module procedure fmin88
        module procedure fmin44
        module procedure fmin84
        module procedure fmin48
    end interface
contains
    real(8) function fmax88(x, y) result (res)
        real(8), intent (in) :: x
        real(8), intent (in) :: y
        res = merge(y, merge(x, max(x, y), y /= y), x /= x)
    end function
    real(4) function fmax44(x, y) result (res)
        real(4), intent (in) :: x
        real(4), intent (in) :: y
        res = merge(y, merge(x, max(x, y), y /= y), x /= x)
    end function
    real(8) function fmax84(x, y) result(res)
        real(8), intent (in) :: x
        real(4), intent (in) :: y
        res = merge(dble(y), merge(x, max(x, dble(y)), y /= y), x /= x)
    end function
    real(8) function fmax48(x, y) result(res)
        real(4), intent (in) :: x
        real(8), intent (in) :: y
        res = merge(y, merge(dble(x), max(dble(x), y), y /= y), x /= x)
    end function
    real(8) function fmin88(x, y) result (res)
        real(8), intent (in) :: x
        real(8), intent (in) :: y
        res = merge(y, merge(x, min(x, y), y /= y), x /= x)
    end function
    real(4) function fmin44(x, y) result (res)
        real(4), intent (in) :: x
        real(4), intent (in) :: y
        res = merge(y, merge(x, min(x, y), y /= y), x /= x)
    end function
    real(8) function fmin84(x, y) result(res)
        real(8), intent (in) :: x
        real(4), intent (in) :: y
        res = merge(dble(y), merge(x, min(x, dble(y)), y /= y), x /= x)
    end function
    real(8) function fmin48(x, y) result(res)
        real(4), intent (in) :: x
        real(8), intent (in) :: y
        res = merge(y, merge(dble(x), min(dble(x), y), y /= y), x /= x)
    end function
end module

real(8) function code(x, y_m, z)
use fmin_fmax_functions
    real(8), intent (in) :: x
    real(8), intent (in) :: y_m
    real(8), intent (in) :: z
    real(8) :: t_0
    real(8) :: tmp
    t_0 = abs((x / y_m))
    if (x <= (-1.52d0)) then
        tmp = t_0
    else if (x <= 4.0d0) then
        tmp = abs((4.0d0 / y_m))
    else
        tmp = t_0
    end if
    code = tmp
end function
y_m = Math.abs(y);
public static double code(double x, double y_m, double z) {
	double t_0 = Math.abs((x / y_m));
	double tmp;
	if (x <= -1.52) {
		tmp = t_0;
	} else if (x <= 4.0) {
		tmp = Math.abs((4.0 / y_m));
	} else {
		tmp = t_0;
	}
	return tmp;
}
y_m = math.fabs(y)
def code(x, y_m, z):
	t_0 = math.fabs((x / y_m))
	tmp = 0
	if x <= -1.52:
		tmp = t_0
	elif x <= 4.0:
		tmp = math.fabs((4.0 / y_m))
	else:
		tmp = t_0
	return tmp
y_m = abs(y)
function code(x, y_m, z)
	t_0 = abs(Float64(x / y_m))
	tmp = 0.0
	if (x <= -1.52)
		tmp = t_0;
	elseif (x <= 4.0)
		tmp = abs(Float64(4.0 / y_m));
	else
		tmp = t_0;
	end
	return tmp
end
y_m = abs(y);
function tmp_2 = code(x, y_m, z)
	t_0 = abs((x / y_m));
	tmp = 0.0;
	if (x <= -1.52)
		tmp = t_0;
	elseif (x <= 4.0)
		tmp = abs((4.0 / y_m));
	else
		tmp = t_0;
	end
	tmp_2 = tmp;
end
y_m = N[Abs[y], $MachinePrecision]
code[x_, y$95$m_, z_] := Block[{t$95$0 = N[Abs[N[(x / y$95$m), $MachinePrecision]], $MachinePrecision]}, If[LessEqual[x, -1.52], t$95$0, If[LessEqual[x, 4.0], N[Abs[N[(4.0 / y$95$m), $MachinePrecision]], $MachinePrecision], t$95$0]]]
\begin{array}{l}
y_m = \left|y\right|

\\
\begin{array}{l}
t_0 := \left|\frac{x}{y\_m}\right|\\
\mathbf{if}\;x \leq -1.52:\\
\;\;\;\;t\_0\\

\mathbf{elif}\;x \leq 4:\\
\;\;\;\;\left|\frac{4}{y\_m}\right|\\

\mathbf{else}:\\
\;\;\;\;t\_0\\


\end{array}
\end{array}
Derivation
  1. Split input into 2 regimes
  2. if x < -1.52 or 4 < x

    1. Initial program 91.6%

      \[\left|\frac{x + 4}{y} - \frac{x}{y} \cdot z\right| \]
    2. Taylor expanded in x around inf

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

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

        \[\leadsto \left|\left(\frac{1}{y} - \frac{z}{y}\right) \cdot \color{blue}{x}\right| \]
      3. sub-divN/A

        \[\leadsto \left|\frac{1 - z}{y} \cdot x\right| \]
      4. lower-/.f64N/A

        \[\leadsto \left|\frac{1 - z}{y} \cdot x\right| \]
      5. lower--.f6461.1

        \[\leadsto \left|\frac{1 - z}{y} \cdot x\right| \]
    4. Applied rewrites61.1%

      \[\leadsto \left|\color{blue}{\frac{1 - z}{y} \cdot x}\right| \]
    5. Taylor expanded in z around 0

      \[\leadsto \left|\frac{x}{\color{blue}{y}}\right| \]
    6. Step-by-step derivation
      1. lower-/.f6433.8

        \[\leadsto \left|\frac{x}{y}\right| \]
    7. Applied rewrites33.8%

      \[\leadsto \left|\frac{x}{\color{blue}{y}}\right| \]

    if -1.52 < x < 4

    1. Initial program 91.6%

      \[\left|\frac{x + 4}{y} - \frac{x}{y} \cdot z\right| \]
    2. Taylor expanded in x around 0

      \[\leadsto \left|\color{blue}{\frac{4}{y}}\right| \]
    3. Step-by-step derivation
      1. lower-/.f6440.5

        \[\leadsto \left|\frac{4}{\color{blue}{y}}\right| \]
    4. Applied rewrites40.5%

      \[\leadsto \left|\color{blue}{\frac{4}{y}}\right| \]
  3. Recombined 2 regimes into one program.
  4. Add Preprocessing

Alternative 7: 33.8% accurate, 3.1× speedup?

\[\begin{array}{l} y_m = \left|y\right| \\ \left|\frac{x}{y\_m}\right| \end{array} \]
y_m = (fabs.f64 y)
(FPCore (x y_m z) :precision binary64 (fabs (/ x y_m)))
y_m = fabs(y);
double code(double x, double y_m, double z) {
	return fabs((x / y_m));
}
y_m =     private
module fmin_fmax_functions
    implicit none
    private
    public fmax
    public fmin

    interface fmax
        module procedure fmax88
        module procedure fmax44
        module procedure fmax84
        module procedure fmax48
    end interface
    interface fmin
        module procedure fmin88
        module procedure fmin44
        module procedure fmin84
        module procedure fmin48
    end interface
contains
    real(8) function fmax88(x, y) result (res)
        real(8), intent (in) :: x
        real(8), intent (in) :: y
        res = merge(y, merge(x, max(x, y), y /= y), x /= x)
    end function
    real(4) function fmax44(x, y) result (res)
        real(4), intent (in) :: x
        real(4), intent (in) :: y
        res = merge(y, merge(x, max(x, y), y /= y), x /= x)
    end function
    real(8) function fmax84(x, y) result(res)
        real(8), intent (in) :: x
        real(4), intent (in) :: y
        res = merge(dble(y), merge(x, max(x, dble(y)), y /= y), x /= x)
    end function
    real(8) function fmax48(x, y) result(res)
        real(4), intent (in) :: x
        real(8), intent (in) :: y
        res = merge(y, merge(dble(x), max(dble(x), y), y /= y), x /= x)
    end function
    real(8) function fmin88(x, y) result (res)
        real(8), intent (in) :: x
        real(8), intent (in) :: y
        res = merge(y, merge(x, min(x, y), y /= y), x /= x)
    end function
    real(4) function fmin44(x, y) result (res)
        real(4), intent (in) :: x
        real(4), intent (in) :: y
        res = merge(y, merge(x, min(x, y), y /= y), x /= x)
    end function
    real(8) function fmin84(x, y) result(res)
        real(8), intent (in) :: x
        real(4), intent (in) :: y
        res = merge(dble(y), merge(x, min(x, dble(y)), y /= y), x /= x)
    end function
    real(8) function fmin48(x, y) result(res)
        real(4), intent (in) :: x
        real(8), intent (in) :: y
        res = merge(y, merge(dble(x), min(dble(x), y), y /= y), x /= x)
    end function
end module

real(8) function code(x, y_m, z)
use fmin_fmax_functions
    real(8), intent (in) :: x
    real(8), intent (in) :: y_m
    real(8), intent (in) :: z
    code = abs((x / y_m))
end function
y_m = Math.abs(y);
public static double code(double x, double y_m, double z) {
	return Math.abs((x / y_m));
}
y_m = math.fabs(y)
def code(x, y_m, z):
	return math.fabs((x / y_m))
y_m = abs(y)
function code(x, y_m, z)
	return abs(Float64(x / y_m))
end
y_m = abs(y);
function tmp = code(x, y_m, z)
	tmp = abs((x / y_m));
end
y_m = N[Abs[y], $MachinePrecision]
code[x_, y$95$m_, z_] := N[Abs[N[(x / y$95$m), $MachinePrecision]], $MachinePrecision]
\begin{array}{l}
y_m = \left|y\right|

\\
\left|\frac{x}{y\_m}\right|
\end{array}
Derivation
  1. Initial program 91.6%

    \[\left|\frac{x + 4}{y} - \frac{x}{y} \cdot z\right| \]
  2. Taylor expanded in x around inf

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

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

      \[\leadsto \left|\left(\frac{1}{y} - \frac{z}{y}\right) \cdot \color{blue}{x}\right| \]
    3. sub-divN/A

      \[\leadsto \left|\frac{1 - z}{y} \cdot x\right| \]
    4. lower-/.f64N/A

      \[\leadsto \left|\frac{1 - z}{y} \cdot x\right| \]
    5. lower--.f6461.1

      \[\leadsto \left|\frac{1 - z}{y} \cdot x\right| \]
  4. Applied rewrites61.1%

    \[\leadsto \left|\color{blue}{\frac{1 - z}{y} \cdot x}\right| \]
  5. Taylor expanded in z around 0

    \[\leadsto \left|\frac{x}{\color{blue}{y}}\right| \]
  6. Step-by-step derivation
    1. lower-/.f6433.8

      \[\leadsto \left|\frac{x}{y}\right| \]
  7. Applied rewrites33.8%

    \[\leadsto \left|\frac{x}{\color{blue}{y}}\right| \]
  8. Add Preprocessing

Reproduce

?
herbie shell --seed 2025124 
(FPCore (x y z)
  :name "fabs fraction 1"
  :precision binary64
  (fabs (- (/ (+ x 4.0) y) (* (/ x y) z))))