Complex division, imag part

Percentage Accurate: 61.8% → 93.0%
Time: 9.7s
Alternatives: 8
Speedup: 1.1×

Specification

?
\[\begin{array}{l} \\ \frac{b \cdot c - a \cdot d}{c \cdot c + d \cdot d} \end{array} \]
(FPCore (a b c d)
 :precision binary64
 (/ (- (* b c) (* a d)) (+ (* c c) (* d d))))
double code(double a, double b, double c, double d) {
	return ((b * c) - (a * d)) / ((c * c) + (d * d));
}
real(8) function code(a, b, c, d)
    real(8), intent (in) :: a
    real(8), intent (in) :: b
    real(8), intent (in) :: c
    real(8), intent (in) :: d
    code = ((b * c) - (a * d)) / ((c * c) + (d * d))
end function
public static double code(double a, double b, double c, double d) {
	return ((b * c) - (a * d)) / ((c * c) + (d * d));
}
def code(a, b, c, d):
	return ((b * c) - (a * d)) / ((c * c) + (d * d))
function code(a, b, c, d)
	return Float64(Float64(Float64(b * c) - Float64(a * d)) / Float64(Float64(c * c) + Float64(d * d)))
end
function tmp = code(a, b, c, d)
	tmp = ((b * c) - (a * d)) / ((c * c) + (d * d));
end
code[a_, b_, c_, d_] := N[(N[(N[(b * c), $MachinePrecision] - N[(a * d), $MachinePrecision]), $MachinePrecision] / N[(N[(c * c), $MachinePrecision] + N[(d * d), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}

\\
\frac{b \cdot c - a \cdot d}{c \cdot c + d \cdot d}
\end{array}

Sampling outcomes in binary64 precision:

Local Percentage Accuracy vs ?

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

Accuracy vs Speed?

Herbie found 8 alternatives:

AlternativeAccuracySpeedup
The accuracy (vertical axis) and speed (horizontal axis) of each alternatives. Up and to the right is better. The red square shows the initial program, and each blue circle shows an alternative.The line shows the best available speed-accuracy tradeoffs.

Initial Program: 61.8% accurate, 1.0× speedup?

\[\begin{array}{l} \\ \frac{b \cdot c - a \cdot d}{c \cdot c + d \cdot d} \end{array} \]
(FPCore (a b c d)
 :precision binary64
 (/ (- (* b c) (* a d)) (+ (* c c) (* d d))))
double code(double a, double b, double c, double d) {
	return ((b * c) - (a * d)) / ((c * c) + (d * d));
}
real(8) function code(a, b, c, d)
    real(8), intent (in) :: a
    real(8), intent (in) :: b
    real(8), intent (in) :: c
    real(8), intent (in) :: d
    code = ((b * c) - (a * d)) / ((c * c) + (d * d))
end function
public static double code(double a, double b, double c, double d) {
	return ((b * c) - (a * d)) / ((c * c) + (d * d));
}
def code(a, b, c, d):
	return ((b * c) - (a * d)) / ((c * c) + (d * d))
function code(a, b, c, d)
	return Float64(Float64(Float64(b * c) - Float64(a * d)) / Float64(Float64(c * c) + Float64(d * d)))
end
function tmp = code(a, b, c, d)
	tmp = ((b * c) - (a * d)) / ((c * c) + (d * d));
end
code[a_, b_, c_, d_] := N[(N[(N[(b * c), $MachinePrecision] - N[(a * d), $MachinePrecision]), $MachinePrecision] / N[(N[(c * c), $MachinePrecision] + N[(d * d), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}

\\
\frac{b \cdot c - a \cdot d}{c \cdot c + d \cdot d}
\end{array}

Alternative 1: 93.0% accurate, 0.0× speedup?

\[\begin{array}{l} \\ \begin{array}{l} t_0 := \frac{c}{\mathsf{hypot}\left(c, d\right)}\\ t_1 := \frac{b}{\mathsf{hypot}\left(c, d\right)}\\ t_2 := \mathsf{fma}\left(t\_0, t\_1, a \cdot \frac{d}{-{\left(\mathsf{hypot}\left(c, d\right)\right)}^{2}}\right)\\ t_3 := \mathsf{fma}\left(t\_0, t\_1, \frac{-a}{d}\right)\\ \mathbf{if}\;d \leq -2.2 \cdot 10^{+145}:\\ \;\;\;\;t\_3\\ \mathbf{elif}\;d \leq -1 \cdot 10^{-158}:\\ \;\;\;\;t\_2\\ \mathbf{elif}\;d \leq 2.25 \cdot 10^{-132}:\\ \;\;\;\;\frac{b - a \cdot \frac{d}{c}}{c}\\ \mathbf{elif}\;d \leq 1.25 \cdot 10^{+98}:\\ \;\;\;\;t\_2\\ \mathbf{else}:\\ \;\;\;\;t\_3\\ \end{array} \end{array} \]
(FPCore (a b c d)
 :precision binary64
 (let* ((t_0 (/ c (hypot c d)))
        (t_1 (/ b (hypot c d)))
        (t_2 (fma t_0 t_1 (* a (/ d (- (pow (hypot c d) 2.0))))))
        (t_3 (fma t_0 t_1 (/ (- a) d))))
   (if (<= d -2.2e+145)
     t_3
     (if (<= d -1e-158)
       t_2
       (if (<= d 2.25e-132)
         (/ (- b (* a (/ d c))) c)
         (if (<= d 1.25e+98) t_2 t_3))))))
double code(double a, double b, double c, double d) {
	double t_0 = c / hypot(c, d);
	double t_1 = b / hypot(c, d);
	double t_2 = fma(t_0, t_1, (a * (d / -pow(hypot(c, d), 2.0))));
	double t_3 = fma(t_0, t_1, (-a / d));
	double tmp;
	if (d <= -2.2e+145) {
		tmp = t_3;
	} else if (d <= -1e-158) {
		tmp = t_2;
	} else if (d <= 2.25e-132) {
		tmp = (b - (a * (d / c))) / c;
	} else if (d <= 1.25e+98) {
		tmp = t_2;
	} else {
		tmp = t_3;
	}
	return tmp;
}
function code(a, b, c, d)
	t_0 = Float64(c / hypot(c, d))
	t_1 = Float64(b / hypot(c, d))
	t_2 = fma(t_0, t_1, Float64(a * Float64(d / Float64(-(hypot(c, d) ^ 2.0)))))
	t_3 = fma(t_0, t_1, Float64(Float64(-a) / d))
	tmp = 0.0
	if (d <= -2.2e+145)
		tmp = t_3;
	elseif (d <= -1e-158)
		tmp = t_2;
	elseif (d <= 2.25e-132)
		tmp = Float64(Float64(b - Float64(a * Float64(d / c))) / c);
	elseif (d <= 1.25e+98)
		tmp = t_2;
	else
		tmp = t_3;
	end
	return tmp
end
code[a_, b_, c_, d_] := Block[{t$95$0 = N[(c / N[Sqrt[c ^ 2 + d ^ 2], $MachinePrecision]), $MachinePrecision]}, Block[{t$95$1 = N[(b / N[Sqrt[c ^ 2 + d ^ 2], $MachinePrecision]), $MachinePrecision]}, Block[{t$95$2 = N[(t$95$0 * t$95$1 + N[(a * N[(d / (-N[Power[N[Sqrt[c ^ 2 + d ^ 2], $MachinePrecision], 2.0], $MachinePrecision])), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]}, Block[{t$95$3 = N[(t$95$0 * t$95$1 + N[((-a) / d), $MachinePrecision]), $MachinePrecision]}, If[LessEqual[d, -2.2e+145], t$95$3, If[LessEqual[d, -1e-158], t$95$2, If[LessEqual[d, 2.25e-132], N[(N[(b - N[(a * N[(d / c), $MachinePrecision]), $MachinePrecision]), $MachinePrecision] / c), $MachinePrecision], If[LessEqual[d, 1.25e+98], t$95$2, t$95$3]]]]]]]]
\begin{array}{l}

\\
\begin{array}{l}
t_0 := \frac{c}{\mathsf{hypot}\left(c, d\right)}\\
t_1 := \frac{b}{\mathsf{hypot}\left(c, d\right)}\\
t_2 := \mathsf{fma}\left(t\_0, t\_1, a \cdot \frac{d}{-{\left(\mathsf{hypot}\left(c, d\right)\right)}^{2}}\right)\\
t_3 := \mathsf{fma}\left(t\_0, t\_1, \frac{-a}{d}\right)\\
\mathbf{if}\;d \leq -2.2 \cdot 10^{+145}:\\
\;\;\;\;t\_3\\

\mathbf{elif}\;d \leq -1 \cdot 10^{-158}:\\
\;\;\;\;t\_2\\

\mathbf{elif}\;d \leq 2.25 \cdot 10^{-132}:\\
\;\;\;\;\frac{b - a \cdot \frac{d}{c}}{c}\\

\mathbf{elif}\;d \leq 1.25 \cdot 10^{+98}:\\
\;\;\;\;t\_2\\

\mathbf{else}:\\
\;\;\;\;t\_3\\


\end{array}
\end{array}
Derivation
  1. Split input into 3 regimes
  2. if d < -2.20000000000000009e145 or 1.25e98 < d

    1. Initial program 40.2%

      \[\frac{b \cdot c - a \cdot d}{c \cdot c + d \cdot d} \]
    2. Add Preprocessing
    3. Step-by-step derivation
      1. div-sub40.2%

        \[\leadsto \color{blue}{\frac{b \cdot c}{c \cdot c + d \cdot d} - \frac{a \cdot d}{c \cdot c + d \cdot d}} \]
      2. *-commutative40.2%

        \[\leadsto \frac{\color{blue}{c \cdot b}}{c \cdot c + d \cdot d} - \frac{a \cdot d}{c \cdot c + d \cdot d} \]
      3. fma-define40.2%

        \[\leadsto \frac{c \cdot b}{\color{blue}{\mathsf{fma}\left(c, c, d \cdot d\right)}} - \frac{a \cdot d}{c \cdot c + d \cdot d} \]
      4. add-sqr-sqrt40.2%

        \[\leadsto \frac{c \cdot b}{\color{blue}{\sqrt{\mathsf{fma}\left(c, c, d \cdot d\right)} \cdot \sqrt{\mathsf{fma}\left(c, c, d \cdot d\right)}}} - \frac{a \cdot d}{c \cdot c + d \cdot d} \]
      5. times-frac40.5%

        \[\leadsto \color{blue}{\frac{c}{\sqrt{\mathsf{fma}\left(c, c, d \cdot d\right)}} \cdot \frac{b}{\sqrt{\mathsf{fma}\left(c, c, d \cdot d\right)}}} - \frac{a \cdot d}{c \cdot c + d \cdot d} \]
      6. fma-neg40.5%

        \[\leadsto \color{blue}{\mathsf{fma}\left(\frac{c}{\sqrt{\mathsf{fma}\left(c, c, d \cdot d\right)}}, \frac{b}{\sqrt{\mathsf{fma}\left(c, c, d \cdot d\right)}}, -\frac{a \cdot d}{c \cdot c + d \cdot d}\right)} \]
      7. fma-define40.5%

        \[\leadsto \mathsf{fma}\left(\frac{c}{\sqrt{\color{blue}{c \cdot c + d \cdot d}}}, \frac{b}{\sqrt{\mathsf{fma}\left(c, c, d \cdot d\right)}}, -\frac{a \cdot d}{c \cdot c + d \cdot d}\right) \]
      8. hypot-define40.5%

        \[\leadsto \mathsf{fma}\left(\frac{c}{\color{blue}{\mathsf{hypot}\left(c, d\right)}}, \frac{b}{\sqrt{\mathsf{fma}\left(c, c, d \cdot d\right)}}, -\frac{a \cdot d}{c \cdot c + d \cdot d}\right) \]
      9. fma-define40.5%

        \[\leadsto \mathsf{fma}\left(\frac{c}{\mathsf{hypot}\left(c, d\right)}, \frac{b}{\sqrt{\color{blue}{c \cdot c + d \cdot d}}}, -\frac{a \cdot d}{c \cdot c + d \cdot d}\right) \]
      10. hypot-define55.9%

        \[\leadsto \mathsf{fma}\left(\frac{c}{\mathsf{hypot}\left(c, d\right)}, \frac{b}{\color{blue}{\mathsf{hypot}\left(c, d\right)}}, -\frac{a \cdot d}{c \cdot c + d \cdot d}\right) \]
      11. associate-/l*62.9%

        \[\leadsto \mathsf{fma}\left(\frac{c}{\mathsf{hypot}\left(c, d\right)}, \frac{b}{\mathsf{hypot}\left(c, d\right)}, -\color{blue}{a \cdot \frac{d}{c \cdot c + d \cdot d}}\right) \]
      12. fma-define62.9%

        \[\leadsto \mathsf{fma}\left(\frac{c}{\mathsf{hypot}\left(c, d\right)}, \frac{b}{\mathsf{hypot}\left(c, d\right)}, -a \cdot \frac{d}{\color{blue}{\mathsf{fma}\left(c, c, d \cdot d\right)}}\right) \]
      13. add-sqr-sqrt62.9%

        \[\leadsto \mathsf{fma}\left(\frac{c}{\mathsf{hypot}\left(c, d\right)}, \frac{b}{\mathsf{hypot}\left(c, d\right)}, -a \cdot \frac{d}{\color{blue}{\sqrt{\mathsf{fma}\left(c, c, d \cdot d\right)} \cdot \sqrt{\mathsf{fma}\left(c, c, d \cdot d\right)}}}\right) \]
      14. pow262.9%

        \[\leadsto \mathsf{fma}\left(\frac{c}{\mathsf{hypot}\left(c, d\right)}, \frac{b}{\mathsf{hypot}\left(c, d\right)}, -a \cdot \frac{d}{\color{blue}{{\left(\sqrt{\mathsf{fma}\left(c, c, d \cdot d\right)}\right)}^{2}}}\right) \]
    4. Applied egg-rr62.9%

      \[\leadsto \color{blue}{\mathsf{fma}\left(\frac{c}{\mathsf{hypot}\left(c, d\right)}, \frac{b}{\mathsf{hypot}\left(c, d\right)}, -a \cdot \frac{d}{{\left(\mathsf{hypot}\left(c, d\right)\right)}^{2}}\right)} \]
    5. Taylor expanded in d around inf 96.3%

      \[\leadsto \mathsf{fma}\left(\frac{c}{\mathsf{hypot}\left(c, d\right)}, \frac{b}{\mathsf{hypot}\left(c, d\right)}, -\color{blue}{\frac{a}{d}}\right) \]

    if -2.20000000000000009e145 < d < -1.00000000000000006e-158 or 2.25e-132 < d < 1.25e98

    1. Initial program 78.9%

      \[\frac{b \cdot c - a \cdot d}{c \cdot c + d \cdot d} \]
    2. Add Preprocessing
    3. Step-by-step derivation
      1. div-sub78.9%

        \[\leadsto \color{blue}{\frac{b \cdot c}{c \cdot c + d \cdot d} - \frac{a \cdot d}{c \cdot c + d \cdot d}} \]
      2. *-commutative78.9%

        \[\leadsto \frac{\color{blue}{c \cdot b}}{c \cdot c + d \cdot d} - \frac{a \cdot d}{c \cdot c + d \cdot d} \]
      3. fma-define78.9%

        \[\leadsto \frac{c \cdot b}{\color{blue}{\mathsf{fma}\left(c, c, d \cdot d\right)}} - \frac{a \cdot d}{c \cdot c + d \cdot d} \]
      4. add-sqr-sqrt78.9%

        \[\leadsto \frac{c \cdot b}{\color{blue}{\sqrt{\mathsf{fma}\left(c, c, d \cdot d\right)} \cdot \sqrt{\mathsf{fma}\left(c, c, d \cdot d\right)}}} - \frac{a \cdot d}{c \cdot c + d \cdot d} \]
      5. times-frac79.1%

        \[\leadsto \color{blue}{\frac{c}{\sqrt{\mathsf{fma}\left(c, c, d \cdot d\right)}} \cdot \frac{b}{\sqrt{\mathsf{fma}\left(c, c, d \cdot d\right)}}} - \frac{a \cdot d}{c \cdot c + d \cdot d} \]
      6. fma-neg79.1%

        \[\leadsto \color{blue}{\mathsf{fma}\left(\frac{c}{\sqrt{\mathsf{fma}\left(c, c, d \cdot d\right)}}, \frac{b}{\sqrt{\mathsf{fma}\left(c, c, d \cdot d\right)}}, -\frac{a \cdot d}{c \cdot c + d \cdot d}\right)} \]
      7. fma-define79.1%

        \[\leadsto \mathsf{fma}\left(\frac{c}{\sqrt{\color{blue}{c \cdot c + d \cdot d}}}, \frac{b}{\sqrt{\mathsf{fma}\left(c, c, d \cdot d\right)}}, -\frac{a \cdot d}{c \cdot c + d \cdot d}\right) \]
      8. hypot-define79.1%

        \[\leadsto \mathsf{fma}\left(\frac{c}{\color{blue}{\mathsf{hypot}\left(c, d\right)}}, \frac{b}{\sqrt{\mathsf{fma}\left(c, c, d \cdot d\right)}}, -\frac{a \cdot d}{c \cdot c + d \cdot d}\right) \]
      9. fma-define79.1%

        \[\leadsto \mathsf{fma}\left(\frac{c}{\mathsf{hypot}\left(c, d\right)}, \frac{b}{\sqrt{\color{blue}{c \cdot c + d \cdot d}}}, -\frac{a \cdot d}{c \cdot c + d \cdot d}\right) \]
      10. hypot-define90.4%

        \[\leadsto \mathsf{fma}\left(\frac{c}{\mathsf{hypot}\left(c, d\right)}, \frac{b}{\color{blue}{\mathsf{hypot}\left(c, d\right)}}, -\frac{a \cdot d}{c \cdot c + d \cdot d}\right) \]
      11. associate-/l*95.2%

        \[\leadsto \mathsf{fma}\left(\frac{c}{\mathsf{hypot}\left(c, d\right)}, \frac{b}{\mathsf{hypot}\left(c, d\right)}, -\color{blue}{a \cdot \frac{d}{c \cdot c + d \cdot d}}\right) \]
      12. fma-define95.2%

        \[\leadsto \mathsf{fma}\left(\frac{c}{\mathsf{hypot}\left(c, d\right)}, \frac{b}{\mathsf{hypot}\left(c, d\right)}, -a \cdot \frac{d}{\color{blue}{\mathsf{fma}\left(c, c, d \cdot d\right)}}\right) \]
      13. add-sqr-sqrt95.2%

        \[\leadsto \mathsf{fma}\left(\frac{c}{\mathsf{hypot}\left(c, d\right)}, \frac{b}{\mathsf{hypot}\left(c, d\right)}, -a \cdot \frac{d}{\color{blue}{\sqrt{\mathsf{fma}\left(c, c, d \cdot d\right)} \cdot \sqrt{\mathsf{fma}\left(c, c, d \cdot d\right)}}}\right) \]
      14. pow295.2%

        \[\leadsto \mathsf{fma}\left(\frac{c}{\mathsf{hypot}\left(c, d\right)}, \frac{b}{\mathsf{hypot}\left(c, d\right)}, -a \cdot \frac{d}{\color{blue}{{\left(\sqrt{\mathsf{fma}\left(c, c, d \cdot d\right)}\right)}^{2}}}\right) \]
    4. Applied egg-rr95.2%

      \[\leadsto \color{blue}{\mathsf{fma}\left(\frac{c}{\mathsf{hypot}\left(c, d\right)}, \frac{b}{\mathsf{hypot}\left(c, d\right)}, -a \cdot \frac{d}{{\left(\mathsf{hypot}\left(c, d\right)\right)}^{2}}\right)} \]

    if -1.00000000000000006e-158 < d < 2.25e-132

    1. Initial program 72.1%

      \[\frac{b \cdot c - a \cdot d}{c \cdot c + d \cdot d} \]
    2. Add Preprocessing
    3. Step-by-step derivation
      1. div-sub66.5%

        \[\leadsto \color{blue}{\frac{b \cdot c}{c \cdot c + d \cdot d} - \frac{a \cdot d}{c \cdot c + d \cdot d}} \]
      2. *-commutative66.5%

        \[\leadsto \frac{\color{blue}{c \cdot b}}{c \cdot c + d \cdot d} - \frac{a \cdot d}{c \cdot c + d \cdot d} \]
      3. fma-define66.5%

        \[\leadsto \frac{c \cdot b}{\color{blue}{\mathsf{fma}\left(c, c, d \cdot d\right)}} - \frac{a \cdot d}{c \cdot c + d \cdot d} \]
      4. add-sqr-sqrt66.5%

        \[\leadsto \frac{c \cdot b}{\color{blue}{\sqrt{\mathsf{fma}\left(c, c, d \cdot d\right)} \cdot \sqrt{\mathsf{fma}\left(c, c, d \cdot d\right)}}} - \frac{a \cdot d}{c \cdot c + d \cdot d} \]
      5. times-frac72.0%

        \[\leadsto \color{blue}{\frac{c}{\sqrt{\mathsf{fma}\left(c, c, d \cdot d\right)}} \cdot \frac{b}{\sqrt{\mathsf{fma}\left(c, c, d \cdot d\right)}}} - \frac{a \cdot d}{c \cdot c + d \cdot d} \]
      6. fma-neg72.0%

        \[\leadsto \color{blue}{\mathsf{fma}\left(\frac{c}{\sqrt{\mathsf{fma}\left(c, c, d \cdot d\right)}}, \frac{b}{\sqrt{\mathsf{fma}\left(c, c, d \cdot d\right)}}, -\frac{a \cdot d}{c \cdot c + d \cdot d}\right)} \]
      7. fma-define72.0%

        \[\leadsto \mathsf{fma}\left(\frac{c}{\sqrt{\color{blue}{c \cdot c + d \cdot d}}}, \frac{b}{\sqrt{\mathsf{fma}\left(c, c, d \cdot d\right)}}, -\frac{a \cdot d}{c \cdot c + d \cdot d}\right) \]
      8. hypot-define72.0%

        \[\leadsto \mathsf{fma}\left(\frac{c}{\color{blue}{\mathsf{hypot}\left(c, d\right)}}, \frac{b}{\sqrt{\mathsf{fma}\left(c, c, d \cdot d\right)}}, -\frac{a \cdot d}{c \cdot c + d \cdot d}\right) \]
      9. fma-define72.0%

        \[\leadsto \mathsf{fma}\left(\frac{c}{\mathsf{hypot}\left(c, d\right)}, \frac{b}{\sqrt{\color{blue}{c \cdot c + d \cdot d}}}, -\frac{a \cdot d}{c \cdot c + d \cdot d}\right) \]
      10. hypot-define88.5%

        \[\leadsto \mathsf{fma}\left(\frac{c}{\mathsf{hypot}\left(c, d\right)}, \frac{b}{\color{blue}{\mathsf{hypot}\left(c, d\right)}}, -\frac{a \cdot d}{c \cdot c + d \cdot d}\right) \]
      11. associate-/l*87.7%

        \[\leadsto \mathsf{fma}\left(\frac{c}{\mathsf{hypot}\left(c, d\right)}, \frac{b}{\mathsf{hypot}\left(c, d\right)}, -\color{blue}{a \cdot \frac{d}{c \cdot c + d \cdot d}}\right) \]
      12. fma-define87.7%

        \[\leadsto \mathsf{fma}\left(\frac{c}{\mathsf{hypot}\left(c, d\right)}, \frac{b}{\mathsf{hypot}\left(c, d\right)}, -a \cdot \frac{d}{\color{blue}{\mathsf{fma}\left(c, c, d \cdot d\right)}}\right) \]
      13. add-sqr-sqrt87.7%

        \[\leadsto \mathsf{fma}\left(\frac{c}{\mathsf{hypot}\left(c, d\right)}, \frac{b}{\mathsf{hypot}\left(c, d\right)}, -a \cdot \frac{d}{\color{blue}{\sqrt{\mathsf{fma}\left(c, c, d \cdot d\right)} \cdot \sqrt{\mathsf{fma}\left(c, c, d \cdot d\right)}}}\right) \]
      14. pow287.7%

        \[\leadsto \mathsf{fma}\left(\frac{c}{\mathsf{hypot}\left(c, d\right)}, \frac{b}{\mathsf{hypot}\left(c, d\right)}, -a \cdot \frac{d}{\color{blue}{{\left(\sqrt{\mathsf{fma}\left(c, c, d \cdot d\right)}\right)}^{2}}}\right) \]
    4. Applied egg-rr87.7%

      \[\leadsto \color{blue}{\mathsf{fma}\left(\frac{c}{\mathsf{hypot}\left(c, d\right)}, \frac{b}{\mathsf{hypot}\left(c, d\right)}, -a \cdot \frac{d}{{\left(\mathsf{hypot}\left(c, d\right)\right)}^{2}}\right)} \]
    5. Taylor expanded in c around inf 93.8%

      \[\leadsto \color{blue}{\frac{b + -1 \cdot \frac{a \cdot d}{c}}{c}} \]
    6. Step-by-step derivation
      1. mul-1-neg93.8%

        \[\leadsto \frac{b + \color{blue}{\left(-\frac{a \cdot d}{c}\right)}}{c} \]
      2. unsub-neg93.8%

        \[\leadsto \frac{\color{blue}{b - \frac{a \cdot d}{c}}}{c} \]
      3. associate-/l*95.1%

        \[\leadsto \frac{b - \color{blue}{a \cdot \frac{d}{c}}}{c} \]
    7. Simplified95.1%

      \[\leadsto \color{blue}{\frac{b - a \cdot \frac{d}{c}}{c}} \]
  3. Recombined 3 regimes into one program.
  4. Final simplification95.5%

    \[\leadsto \begin{array}{l} \mathbf{if}\;d \leq -2.2 \cdot 10^{+145}:\\ \;\;\;\;\mathsf{fma}\left(\frac{c}{\mathsf{hypot}\left(c, d\right)}, \frac{b}{\mathsf{hypot}\left(c, d\right)}, \frac{-a}{d}\right)\\ \mathbf{elif}\;d \leq -1 \cdot 10^{-158}:\\ \;\;\;\;\mathsf{fma}\left(\frac{c}{\mathsf{hypot}\left(c, d\right)}, \frac{b}{\mathsf{hypot}\left(c, d\right)}, a \cdot \frac{d}{-{\left(\mathsf{hypot}\left(c, d\right)\right)}^{2}}\right)\\ \mathbf{elif}\;d \leq 2.25 \cdot 10^{-132}:\\ \;\;\;\;\frac{b - a \cdot \frac{d}{c}}{c}\\ \mathbf{elif}\;d \leq 1.25 \cdot 10^{+98}:\\ \;\;\;\;\mathsf{fma}\left(\frac{c}{\mathsf{hypot}\left(c, d\right)}, \frac{b}{\mathsf{hypot}\left(c, d\right)}, a \cdot \frac{d}{-{\left(\mathsf{hypot}\left(c, d\right)\right)}^{2}}\right)\\ \mathbf{else}:\\ \;\;\;\;\mathsf{fma}\left(\frac{c}{\mathsf{hypot}\left(c, d\right)}, \frac{b}{\mathsf{hypot}\left(c, d\right)}, \frac{-a}{d}\right)\\ \end{array} \]
  5. Add Preprocessing

Alternative 2: 85.4% accurate, 0.0× speedup?

\[\begin{array}{l} \\ \begin{array}{l} t_0 := \frac{c \cdot b - d \cdot a}{c \cdot c + d \cdot d}\\ t_1 := \mathsf{fma}\left(\frac{c}{\mathsf{hypot}\left(c, d\right)}, \frac{b}{\mathsf{hypot}\left(c, d\right)}, \frac{-a}{d}\right)\\ \mathbf{if}\;d \leq -1.8 \cdot 10^{+87}:\\ \;\;\;\;t\_1\\ \mathbf{elif}\;d \leq -9.5 \cdot 10^{-159}:\\ \;\;\;\;t\_0\\ \mathbf{elif}\;d \leq 5.4 \cdot 10^{-92}:\\ \;\;\;\;\frac{b - a \cdot \frac{d}{c}}{c}\\ \mathbf{elif}\;d \leq 1.3 \cdot 10^{+93}:\\ \;\;\;\;t\_0\\ \mathbf{else}:\\ \;\;\;\;t\_1\\ \end{array} \end{array} \]
(FPCore (a b c d)
 :precision binary64
 (let* ((t_0 (/ (- (* c b) (* d a)) (+ (* c c) (* d d))))
        (t_1 (fma (/ c (hypot c d)) (/ b (hypot c d)) (/ (- a) d))))
   (if (<= d -1.8e+87)
     t_1
     (if (<= d -9.5e-159)
       t_0
       (if (<= d 5.4e-92)
         (/ (- b (* a (/ d c))) c)
         (if (<= d 1.3e+93) t_0 t_1))))))
double code(double a, double b, double c, double d) {
	double t_0 = ((c * b) - (d * a)) / ((c * c) + (d * d));
	double t_1 = fma((c / hypot(c, d)), (b / hypot(c, d)), (-a / d));
	double tmp;
	if (d <= -1.8e+87) {
		tmp = t_1;
	} else if (d <= -9.5e-159) {
		tmp = t_0;
	} else if (d <= 5.4e-92) {
		tmp = (b - (a * (d / c))) / c;
	} else if (d <= 1.3e+93) {
		tmp = t_0;
	} else {
		tmp = t_1;
	}
	return tmp;
}
function code(a, b, c, d)
	t_0 = Float64(Float64(Float64(c * b) - Float64(d * a)) / Float64(Float64(c * c) + Float64(d * d)))
	t_1 = fma(Float64(c / hypot(c, d)), Float64(b / hypot(c, d)), Float64(Float64(-a) / d))
	tmp = 0.0
	if (d <= -1.8e+87)
		tmp = t_1;
	elseif (d <= -9.5e-159)
		tmp = t_0;
	elseif (d <= 5.4e-92)
		tmp = Float64(Float64(b - Float64(a * Float64(d / c))) / c);
	elseif (d <= 1.3e+93)
		tmp = t_0;
	else
		tmp = t_1;
	end
	return tmp
end
code[a_, b_, c_, d_] := Block[{t$95$0 = N[(N[(N[(c * b), $MachinePrecision] - N[(d * a), $MachinePrecision]), $MachinePrecision] / N[(N[(c * c), $MachinePrecision] + N[(d * d), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]}, Block[{t$95$1 = N[(N[(c / N[Sqrt[c ^ 2 + d ^ 2], $MachinePrecision]), $MachinePrecision] * N[(b / N[Sqrt[c ^ 2 + d ^ 2], $MachinePrecision]), $MachinePrecision] + N[((-a) / d), $MachinePrecision]), $MachinePrecision]}, If[LessEqual[d, -1.8e+87], t$95$1, If[LessEqual[d, -9.5e-159], t$95$0, If[LessEqual[d, 5.4e-92], N[(N[(b - N[(a * N[(d / c), $MachinePrecision]), $MachinePrecision]), $MachinePrecision] / c), $MachinePrecision], If[LessEqual[d, 1.3e+93], t$95$0, t$95$1]]]]]]
\begin{array}{l}

\\
\begin{array}{l}
t_0 := \frac{c \cdot b - d \cdot a}{c \cdot c + d \cdot d}\\
t_1 := \mathsf{fma}\left(\frac{c}{\mathsf{hypot}\left(c, d\right)}, \frac{b}{\mathsf{hypot}\left(c, d\right)}, \frac{-a}{d}\right)\\
\mathbf{if}\;d \leq -1.8 \cdot 10^{+87}:\\
\;\;\;\;t\_1\\

\mathbf{elif}\;d \leq -9.5 \cdot 10^{-159}:\\
\;\;\;\;t\_0\\

\mathbf{elif}\;d \leq 5.4 \cdot 10^{-92}:\\
\;\;\;\;\frac{b - a \cdot \frac{d}{c}}{c}\\

\mathbf{elif}\;d \leq 1.3 \cdot 10^{+93}:\\
\;\;\;\;t\_0\\

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


\end{array}
\end{array}
Derivation
  1. Split input into 3 regimes
  2. if d < -1.79999999999999997e87 or 1.3e93 < d

    1. Initial program 39.6%

      \[\frac{b \cdot c - a \cdot d}{c \cdot c + d \cdot d} \]
    2. Add Preprocessing
    3. Step-by-step derivation
      1. div-sub39.6%

        \[\leadsto \color{blue}{\frac{b \cdot c}{c \cdot c + d \cdot d} - \frac{a \cdot d}{c \cdot c + d \cdot d}} \]
      2. *-commutative39.6%

        \[\leadsto \frac{\color{blue}{c \cdot b}}{c \cdot c + d \cdot d} - \frac{a \cdot d}{c \cdot c + d \cdot d} \]
      3. fma-define39.6%

        \[\leadsto \frac{c \cdot b}{\color{blue}{\mathsf{fma}\left(c, c, d \cdot d\right)}} - \frac{a \cdot d}{c \cdot c + d \cdot d} \]
      4. add-sqr-sqrt39.6%

        \[\leadsto \frac{c \cdot b}{\color{blue}{\sqrt{\mathsf{fma}\left(c, c, d \cdot d\right)} \cdot \sqrt{\mathsf{fma}\left(c, c, d \cdot d\right)}}} - \frac{a \cdot d}{c \cdot c + d \cdot d} \]
      5. times-frac41.1%

        \[\leadsto \color{blue}{\frac{c}{\sqrt{\mathsf{fma}\left(c, c, d \cdot d\right)}} \cdot \frac{b}{\sqrt{\mathsf{fma}\left(c, c, d \cdot d\right)}}} - \frac{a \cdot d}{c \cdot c + d \cdot d} \]
      6. fma-neg41.1%

        \[\leadsto \color{blue}{\mathsf{fma}\left(\frac{c}{\sqrt{\mathsf{fma}\left(c, c, d \cdot d\right)}}, \frac{b}{\sqrt{\mathsf{fma}\left(c, c, d \cdot d\right)}}, -\frac{a \cdot d}{c \cdot c + d \cdot d}\right)} \]
      7. fma-define41.1%

        \[\leadsto \mathsf{fma}\left(\frac{c}{\sqrt{\color{blue}{c \cdot c + d \cdot d}}}, \frac{b}{\sqrt{\mathsf{fma}\left(c, c, d \cdot d\right)}}, -\frac{a \cdot d}{c \cdot c + d \cdot d}\right) \]
      8. hypot-define41.1%

        \[\leadsto \mathsf{fma}\left(\frac{c}{\color{blue}{\mathsf{hypot}\left(c, d\right)}}, \frac{b}{\sqrt{\mathsf{fma}\left(c, c, d \cdot d\right)}}, -\frac{a \cdot d}{c \cdot c + d \cdot d}\right) \]
      9. fma-define41.1%

        \[\leadsto \mathsf{fma}\left(\frac{c}{\mathsf{hypot}\left(c, d\right)}, \frac{b}{\sqrt{\color{blue}{c \cdot c + d \cdot d}}}, -\frac{a \cdot d}{c \cdot c + d \cdot d}\right) \]
      10. hypot-define55.7%

        \[\leadsto \mathsf{fma}\left(\frac{c}{\mathsf{hypot}\left(c, d\right)}, \frac{b}{\color{blue}{\mathsf{hypot}\left(c, d\right)}}, -\frac{a \cdot d}{c \cdot c + d \cdot d}\right) \]
      11. associate-/l*64.6%

        \[\leadsto \mathsf{fma}\left(\frac{c}{\mathsf{hypot}\left(c, d\right)}, \frac{b}{\mathsf{hypot}\left(c, d\right)}, -\color{blue}{a \cdot \frac{d}{c \cdot c + d \cdot d}}\right) \]
      12. fma-define64.6%

        \[\leadsto \mathsf{fma}\left(\frac{c}{\mathsf{hypot}\left(c, d\right)}, \frac{b}{\mathsf{hypot}\left(c, d\right)}, -a \cdot \frac{d}{\color{blue}{\mathsf{fma}\left(c, c, d \cdot d\right)}}\right) \]
      13. add-sqr-sqrt64.6%

        \[\leadsto \mathsf{fma}\left(\frac{c}{\mathsf{hypot}\left(c, d\right)}, \frac{b}{\mathsf{hypot}\left(c, d\right)}, -a \cdot \frac{d}{\color{blue}{\sqrt{\mathsf{fma}\left(c, c, d \cdot d\right)} \cdot \sqrt{\mathsf{fma}\left(c, c, d \cdot d\right)}}}\right) \]
      14. pow264.6%

        \[\leadsto \mathsf{fma}\left(\frac{c}{\mathsf{hypot}\left(c, d\right)}, \frac{b}{\mathsf{hypot}\left(c, d\right)}, -a \cdot \frac{d}{\color{blue}{{\left(\sqrt{\mathsf{fma}\left(c, c, d \cdot d\right)}\right)}^{2}}}\right) \]
    4. Applied egg-rr64.6%

      \[\leadsto \color{blue}{\mathsf{fma}\left(\frac{c}{\mathsf{hypot}\left(c, d\right)}, \frac{b}{\mathsf{hypot}\left(c, d\right)}, -a \cdot \frac{d}{{\left(\mathsf{hypot}\left(c, d\right)\right)}^{2}}\right)} \]
    5. Taylor expanded in d around inf 95.5%

      \[\leadsto \mathsf{fma}\left(\frac{c}{\mathsf{hypot}\left(c, d\right)}, \frac{b}{\mathsf{hypot}\left(c, d\right)}, -\color{blue}{\frac{a}{d}}\right) \]

    if -1.79999999999999997e87 < d < -9.4999999999999997e-159 or 5.3999999999999999e-92 < d < 1.3e93

    1. Initial program 81.2%

      \[\frac{b \cdot c - a \cdot d}{c \cdot c + d \cdot d} \]
    2. Add Preprocessing

    if -9.4999999999999997e-159 < d < 5.3999999999999999e-92

    1. Initial program 72.8%

      \[\frac{b \cdot c - a \cdot d}{c \cdot c + d \cdot d} \]
    2. Add Preprocessing
    3. Step-by-step derivation
      1. div-sub67.8%

        \[\leadsto \color{blue}{\frac{b \cdot c}{c \cdot c + d \cdot d} - \frac{a \cdot d}{c \cdot c + d \cdot d}} \]
      2. *-commutative67.8%

        \[\leadsto \frac{\color{blue}{c \cdot b}}{c \cdot c + d \cdot d} - \frac{a \cdot d}{c \cdot c + d \cdot d} \]
      3. fma-define67.8%

        \[\leadsto \frac{c \cdot b}{\color{blue}{\mathsf{fma}\left(c, c, d \cdot d\right)}} - \frac{a \cdot d}{c \cdot c + d \cdot d} \]
      4. add-sqr-sqrt67.8%

        \[\leadsto \frac{c \cdot b}{\color{blue}{\sqrt{\mathsf{fma}\left(c, c, d \cdot d\right)} \cdot \sqrt{\mathsf{fma}\left(c, c, d \cdot d\right)}}} - \frac{a \cdot d}{c \cdot c + d \cdot d} \]
      5. times-frac72.7%

        \[\leadsto \color{blue}{\frac{c}{\sqrt{\mathsf{fma}\left(c, c, d \cdot d\right)}} \cdot \frac{b}{\sqrt{\mathsf{fma}\left(c, c, d \cdot d\right)}}} - \frac{a \cdot d}{c \cdot c + d \cdot d} \]
      6. fma-neg72.7%

        \[\leadsto \color{blue}{\mathsf{fma}\left(\frac{c}{\sqrt{\mathsf{fma}\left(c, c, d \cdot d\right)}}, \frac{b}{\sqrt{\mathsf{fma}\left(c, c, d \cdot d\right)}}, -\frac{a \cdot d}{c \cdot c + d \cdot d}\right)} \]
      7. fma-define72.7%

        \[\leadsto \mathsf{fma}\left(\frac{c}{\sqrt{\color{blue}{c \cdot c + d \cdot d}}}, \frac{b}{\sqrt{\mathsf{fma}\left(c, c, d \cdot d\right)}}, -\frac{a \cdot d}{c \cdot c + d \cdot d}\right) \]
      8. hypot-define72.7%

        \[\leadsto \mathsf{fma}\left(\frac{c}{\color{blue}{\mathsf{hypot}\left(c, d\right)}}, \frac{b}{\sqrt{\mathsf{fma}\left(c, c, d \cdot d\right)}}, -\frac{a \cdot d}{c \cdot c + d \cdot d}\right) \]
      9. fma-define72.7%

        \[\leadsto \mathsf{fma}\left(\frac{c}{\mathsf{hypot}\left(c, d\right)}, \frac{b}{\sqrt{\color{blue}{c \cdot c + d \cdot d}}}, -\frac{a \cdot d}{c \cdot c + d \cdot d}\right) \]
      10. hypot-define88.6%

        \[\leadsto \mathsf{fma}\left(\frac{c}{\mathsf{hypot}\left(c, d\right)}, \frac{b}{\color{blue}{\mathsf{hypot}\left(c, d\right)}}, -\frac{a \cdot d}{c \cdot c + d \cdot d}\right) \]
      11. associate-/l*88.9%

        \[\leadsto \mathsf{fma}\left(\frac{c}{\mathsf{hypot}\left(c, d\right)}, \frac{b}{\mathsf{hypot}\left(c, d\right)}, -\color{blue}{a \cdot \frac{d}{c \cdot c + d \cdot d}}\right) \]
      12. fma-define88.9%

        \[\leadsto \mathsf{fma}\left(\frac{c}{\mathsf{hypot}\left(c, d\right)}, \frac{b}{\mathsf{hypot}\left(c, d\right)}, -a \cdot \frac{d}{\color{blue}{\mathsf{fma}\left(c, c, d \cdot d\right)}}\right) \]
      13. add-sqr-sqrt88.9%

        \[\leadsto \mathsf{fma}\left(\frac{c}{\mathsf{hypot}\left(c, d\right)}, \frac{b}{\mathsf{hypot}\left(c, d\right)}, -a \cdot \frac{d}{\color{blue}{\sqrt{\mathsf{fma}\left(c, c, d \cdot d\right)} \cdot \sqrt{\mathsf{fma}\left(c, c, d \cdot d\right)}}}\right) \]
      14. pow288.9%

        \[\leadsto \mathsf{fma}\left(\frac{c}{\mathsf{hypot}\left(c, d\right)}, \frac{b}{\mathsf{hypot}\left(c, d\right)}, -a \cdot \frac{d}{\color{blue}{{\left(\sqrt{\mathsf{fma}\left(c, c, d \cdot d\right)}\right)}^{2}}}\right) \]
    4. Applied egg-rr88.9%

      \[\leadsto \color{blue}{\mathsf{fma}\left(\frac{c}{\mathsf{hypot}\left(c, d\right)}, \frac{b}{\mathsf{hypot}\left(c, d\right)}, -a \cdot \frac{d}{{\left(\mathsf{hypot}\left(c, d\right)\right)}^{2}}\right)} \]
    5. Taylor expanded in c around inf 93.3%

      \[\leadsto \color{blue}{\frac{b + -1 \cdot \frac{a \cdot d}{c}}{c}} \]
    6. Step-by-step derivation
      1. mul-1-neg93.3%

        \[\leadsto \frac{b + \color{blue}{\left(-\frac{a \cdot d}{c}\right)}}{c} \]
      2. unsub-neg93.3%

        \[\leadsto \frac{\color{blue}{b - \frac{a \cdot d}{c}}}{c} \]
      3. associate-/l*94.5%

        \[\leadsto \frac{b - \color{blue}{a \cdot \frac{d}{c}}}{c} \]
    7. Simplified94.5%

      \[\leadsto \color{blue}{\frac{b - a \cdot \frac{d}{c}}{c}} \]
  3. Recombined 3 regimes into one program.
  4. Final simplification90.4%

    \[\leadsto \begin{array}{l} \mathbf{if}\;d \leq -1.8 \cdot 10^{+87}:\\ \;\;\;\;\mathsf{fma}\left(\frac{c}{\mathsf{hypot}\left(c, d\right)}, \frac{b}{\mathsf{hypot}\left(c, d\right)}, \frac{-a}{d}\right)\\ \mathbf{elif}\;d \leq -9.5 \cdot 10^{-159}:\\ \;\;\;\;\frac{c \cdot b - d \cdot a}{c \cdot c + d \cdot d}\\ \mathbf{elif}\;d \leq 5.4 \cdot 10^{-92}:\\ \;\;\;\;\frac{b - a \cdot \frac{d}{c}}{c}\\ \mathbf{elif}\;d \leq 1.3 \cdot 10^{+93}:\\ \;\;\;\;\frac{c \cdot b - d \cdot a}{c \cdot c + d \cdot d}\\ \mathbf{else}:\\ \;\;\;\;\mathsf{fma}\left(\frac{c}{\mathsf{hypot}\left(c, d\right)}, \frac{b}{\mathsf{hypot}\left(c, d\right)}, \frac{-a}{d}\right)\\ \end{array} \]
  5. Add Preprocessing

Alternative 3: 83.3% accurate, 0.4× speedup?

\[\begin{array}{l} \\ \begin{array}{l} t_0 := \frac{c \cdot b - d \cdot a}{c \cdot c + d \cdot d}\\ t_1 := \frac{\frac{c}{\frac{d}{b}} - a}{d}\\ \mathbf{if}\;d \leq -2.7 \cdot 10^{+84}:\\ \;\;\;\;t\_1\\ \mathbf{elif}\;d \leq -2.06 \cdot 10^{-159}:\\ \;\;\;\;t\_0\\ \mathbf{elif}\;d \leq 1.4 \cdot 10^{-97}:\\ \;\;\;\;\frac{b - a \cdot \frac{d}{c}}{c}\\ \mathbf{elif}\;d \leq 6.7 \cdot 10^{+93}:\\ \;\;\;\;t\_0\\ \mathbf{else}:\\ \;\;\;\;t\_1\\ \end{array} \end{array} \]
(FPCore (a b c d)
 :precision binary64
 (let* ((t_0 (/ (- (* c b) (* d a)) (+ (* c c) (* d d))))
        (t_1 (/ (- (/ c (/ d b)) a) d)))
   (if (<= d -2.7e+84)
     t_1
     (if (<= d -2.06e-159)
       t_0
       (if (<= d 1.4e-97)
         (/ (- b (* a (/ d c))) c)
         (if (<= d 6.7e+93) t_0 t_1))))))
double code(double a, double b, double c, double d) {
	double t_0 = ((c * b) - (d * a)) / ((c * c) + (d * d));
	double t_1 = ((c / (d / b)) - a) / d;
	double tmp;
	if (d <= -2.7e+84) {
		tmp = t_1;
	} else if (d <= -2.06e-159) {
		tmp = t_0;
	} else if (d <= 1.4e-97) {
		tmp = (b - (a * (d / c))) / c;
	} else if (d <= 6.7e+93) {
		tmp = t_0;
	} else {
		tmp = t_1;
	}
	return tmp;
}
real(8) function code(a, b, c, d)
    real(8), intent (in) :: a
    real(8), intent (in) :: b
    real(8), intent (in) :: c
    real(8), intent (in) :: d
    real(8) :: t_0
    real(8) :: t_1
    real(8) :: tmp
    t_0 = ((c * b) - (d * a)) / ((c * c) + (d * d))
    t_1 = ((c / (d / b)) - a) / d
    if (d <= (-2.7d+84)) then
        tmp = t_1
    else if (d <= (-2.06d-159)) then
        tmp = t_0
    else if (d <= 1.4d-97) then
        tmp = (b - (a * (d / c))) / c
    else if (d <= 6.7d+93) then
        tmp = t_0
    else
        tmp = t_1
    end if
    code = tmp
end function
public static double code(double a, double b, double c, double d) {
	double t_0 = ((c * b) - (d * a)) / ((c * c) + (d * d));
	double t_1 = ((c / (d / b)) - a) / d;
	double tmp;
	if (d <= -2.7e+84) {
		tmp = t_1;
	} else if (d <= -2.06e-159) {
		tmp = t_0;
	} else if (d <= 1.4e-97) {
		tmp = (b - (a * (d / c))) / c;
	} else if (d <= 6.7e+93) {
		tmp = t_0;
	} else {
		tmp = t_1;
	}
	return tmp;
}
def code(a, b, c, d):
	t_0 = ((c * b) - (d * a)) / ((c * c) + (d * d))
	t_1 = ((c / (d / b)) - a) / d
	tmp = 0
	if d <= -2.7e+84:
		tmp = t_1
	elif d <= -2.06e-159:
		tmp = t_0
	elif d <= 1.4e-97:
		tmp = (b - (a * (d / c))) / c
	elif d <= 6.7e+93:
		tmp = t_0
	else:
		tmp = t_1
	return tmp
function code(a, b, c, d)
	t_0 = Float64(Float64(Float64(c * b) - Float64(d * a)) / Float64(Float64(c * c) + Float64(d * d)))
	t_1 = Float64(Float64(Float64(c / Float64(d / b)) - a) / d)
	tmp = 0.0
	if (d <= -2.7e+84)
		tmp = t_1;
	elseif (d <= -2.06e-159)
		tmp = t_0;
	elseif (d <= 1.4e-97)
		tmp = Float64(Float64(b - Float64(a * Float64(d / c))) / c);
	elseif (d <= 6.7e+93)
		tmp = t_0;
	else
		tmp = t_1;
	end
	return tmp
end
function tmp_2 = code(a, b, c, d)
	t_0 = ((c * b) - (d * a)) / ((c * c) + (d * d));
	t_1 = ((c / (d / b)) - a) / d;
	tmp = 0.0;
	if (d <= -2.7e+84)
		tmp = t_1;
	elseif (d <= -2.06e-159)
		tmp = t_0;
	elseif (d <= 1.4e-97)
		tmp = (b - (a * (d / c))) / c;
	elseif (d <= 6.7e+93)
		tmp = t_0;
	else
		tmp = t_1;
	end
	tmp_2 = tmp;
end
code[a_, b_, c_, d_] := Block[{t$95$0 = N[(N[(N[(c * b), $MachinePrecision] - N[(d * a), $MachinePrecision]), $MachinePrecision] / N[(N[(c * c), $MachinePrecision] + N[(d * d), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]}, Block[{t$95$1 = N[(N[(N[(c / N[(d / b), $MachinePrecision]), $MachinePrecision] - a), $MachinePrecision] / d), $MachinePrecision]}, If[LessEqual[d, -2.7e+84], t$95$1, If[LessEqual[d, -2.06e-159], t$95$0, If[LessEqual[d, 1.4e-97], N[(N[(b - N[(a * N[(d / c), $MachinePrecision]), $MachinePrecision]), $MachinePrecision] / c), $MachinePrecision], If[LessEqual[d, 6.7e+93], t$95$0, t$95$1]]]]]]
\begin{array}{l}

\\
\begin{array}{l}
t_0 := \frac{c \cdot b - d \cdot a}{c \cdot c + d \cdot d}\\
t_1 := \frac{\frac{c}{\frac{d}{b}} - a}{d}\\
\mathbf{if}\;d \leq -2.7 \cdot 10^{+84}:\\
\;\;\;\;t\_1\\

\mathbf{elif}\;d \leq -2.06 \cdot 10^{-159}:\\
\;\;\;\;t\_0\\

\mathbf{elif}\;d \leq 1.4 \cdot 10^{-97}:\\
\;\;\;\;\frac{b - a \cdot \frac{d}{c}}{c}\\

\mathbf{elif}\;d \leq 6.7 \cdot 10^{+93}:\\
\;\;\;\;t\_0\\

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


\end{array}
\end{array}
Derivation
  1. Split input into 3 regimes
  2. if d < -2.7e84 or 6.69999999999999965e93 < d

    1. Initial program 39.6%

      \[\frac{b \cdot c - a \cdot d}{c \cdot c + d \cdot d} \]
    2. Add Preprocessing
    3. Taylor expanded in c around 0 73.5%

      \[\leadsto \color{blue}{-1 \cdot \frac{a}{d} + \frac{b \cdot c}{{d}^{2}}} \]
    4. Step-by-step derivation
      1. +-commutative73.5%

        \[\leadsto \color{blue}{\frac{b \cdot c}{{d}^{2}} + -1 \cdot \frac{a}{d}} \]
      2. mul-1-neg73.5%

        \[\leadsto \frac{b \cdot c}{{d}^{2}} + \color{blue}{\left(-\frac{a}{d}\right)} \]
      3. unsub-neg73.5%

        \[\leadsto \color{blue}{\frac{b \cdot c}{{d}^{2}} - \frac{a}{d}} \]
      4. unpow273.5%

        \[\leadsto \frac{b \cdot c}{\color{blue}{d \cdot d}} - \frac{a}{d} \]
      5. associate-/r*80.4%

        \[\leadsto \color{blue}{\frac{\frac{b \cdot c}{d}}{d}} - \frac{a}{d} \]
      6. div-sub80.4%

        \[\leadsto \color{blue}{\frac{\frac{b \cdot c}{d} - a}{d}} \]
      7. *-commutative80.4%

        \[\leadsto \frac{\frac{\color{blue}{c \cdot b}}{d} - a}{d} \]
      8. associate-/l*87.5%

        \[\leadsto \frac{\color{blue}{c \cdot \frac{b}{d}} - a}{d} \]
    5. Simplified87.5%

      \[\leadsto \color{blue}{\frac{c \cdot \frac{b}{d} - a}{d}} \]
    6. Step-by-step derivation
      1. clear-num87.5%

        \[\leadsto \frac{c \cdot \color{blue}{\frac{1}{\frac{d}{b}}} - a}{d} \]
      2. un-div-inv87.6%

        \[\leadsto \frac{\color{blue}{\frac{c}{\frac{d}{b}}} - a}{d} \]
    7. Applied egg-rr87.6%

      \[\leadsto \frac{\color{blue}{\frac{c}{\frac{d}{b}}} - a}{d} \]

    if -2.7e84 < d < -2.05999999999999989e-159 or 1.4000000000000001e-97 < d < 6.69999999999999965e93

    1. Initial program 81.2%

      \[\frac{b \cdot c - a \cdot d}{c \cdot c + d \cdot d} \]
    2. Add Preprocessing

    if -2.05999999999999989e-159 < d < 1.4000000000000001e-97

    1. Initial program 72.8%

      \[\frac{b \cdot c - a \cdot d}{c \cdot c + d \cdot d} \]
    2. Add Preprocessing
    3. Step-by-step derivation
      1. div-sub67.8%

        \[\leadsto \color{blue}{\frac{b \cdot c}{c \cdot c + d \cdot d} - \frac{a \cdot d}{c \cdot c + d \cdot d}} \]
      2. *-commutative67.8%

        \[\leadsto \frac{\color{blue}{c \cdot b}}{c \cdot c + d \cdot d} - \frac{a \cdot d}{c \cdot c + d \cdot d} \]
      3. fma-define67.8%

        \[\leadsto \frac{c \cdot b}{\color{blue}{\mathsf{fma}\left(c, c, d \cdot d\right)}} - \frac{a \cdot d}{c \cdot c + d \cdot d} \]
      4. add-sqr-sqrt67.8%

        \[\leadsto \frac{c \cdot b}{\color{blue}{\sqrt{\mathsf{fma}\left(c, c, d \cdot d\right)} \cdot \sqrt{\mathsf{fma}\left(c, c, d \cdot d\right)}}} - \frac{a \cdot d}{c \cdot c + d \cdot d} \]
      5. times-frac72.7%

        \[\leadsto \color{blue}{\frac{c}{\sqrt{\mathsf{fma}\left(c, c, d \cdot d\right)}} \cdot \frac{b}{\sqrt{\mathsf{fma}\left(c, c, d \cdot d\right)}}} - \frac{a \cdot d}{c \cdot c + d \cdot d} \]
      6. fma-neg72.7%

        \[\leadsto \color{blue}{\mathsf{fma}\left(\frac{c}{\sqrt{\mathsf{fma}\left(c, c, d \cdot d\right)}}, \frac{b}{\sqrt{\mathsf{fma}\left(c, c, d \cdot d\right)}}, -\frac{a \cdot d}{c \cdot c + d \cdot d}\right)} \]
      7. fma-define72.7%

        \[\leadsto \mathsf{fma}\left(\frac{c}{\sqrt{\color{blue}{c \cdot c + d \cdot d}}}, \frac{b}{\sqrt{\mathsf{fma}\left(c, c, d \cdot d\right)}}, -\frac{a \cdot d}{c \cdot c + d \cdot d}\right) \]
      8. hypot-define72.7%

        \[\leadsto \mathsf{fma}\left(\frac{c}{\color{blue}{\mathsf{hypot}\left(c, d\right)}}, \frac{b}{\sqrt{\mathsf{fma}\left(c, c, d \cdot d\right)}}, -\frac{a \cdot d}{c \cdot c + d \cdot d}\right) \]
      9. fma-define72.7%

        \[\leadsto \mathsf{fma}\left(\frac{c}{\mathsf{hypot}\left(c, d\right)}, \frac{b}{\sqrt{\color{blue}{c \cdot c + d \cdot d}}}, -\frac{a \cdot d}{c \cdot c + d \cdot d}\right) \]
      10. hypot-define88.6%

        \[\leadsto \mathsf{fma}\left(\frac{c}{\mathsf{hypot}\left(c, d\right)}, \frac{b}{\color{blue}{\mathsf{hypot}\left(c, d\right)}}, -\frac{a \cdot d}{c \cdot c + d \cdot d}\right) \]
      11. associate-/l*88.9%

        \[\leadsto \mathsf{fma}\left(\frac{c}{\mathsf{hypot}\left(c, d\right)}, \frac{b}{\mathsf{hypot}\left(c, d\right)}, -\color{blue}{a \cdot \frac{d}{c \cdot c + d \cdot d}}\right) \]
      12. fma-define88.9%

        \[\leadsto \mathsf{fma}\left(\frac{c}{\mathsf{hypot}\left(c, d\right)}, \frac{b}{\mathsf{hypot}\left(c, d\right)}, -a \cdot \frac{d}{\color{blue}{\mathsf{fma}\left(c, c, d \cdot d\right)}}\right) \]
      13. add-sqr-sqrt88.9%

        \[\leadsto \mathsf{fma}\left(\frac{c}{\mathsf{hypot}\left(c, d\right)}, \frac{b}{\mathsf{hypot}\left(c, d\right)}, -a \cdot \frac{d}{\color{blue}{\sqrt{\mathsf{fma}\left(c, c, d \cdot d\right)} \cdot \sqrt{\mathsf{fma}\left(c, c, d \cdot d\right)}}}\right) \]
      14. pow288.9%

        \[\leadsto \mathsf{fma}\left(\frac{c}{\mathsf{hypot}\left(c, d\right)}, \frac{b}{\mathsf{hypot}\left(c, d\right)}, -a \cdot \frac{d}{\color{blue}{{\left(\sqrt{\mathsf{fma}\left(c, c, d \cdot d\right)}\right)}^{2}}}\right) \]
    4. Applied egg-rr88.9%

      \[\leadsto \color{blue}{\mathsf{fma}\left(\frac{c}{\mathsf{hypot}\left(c, d\right)}, \frac{b}{\mathsf{hypot}\left(c, d\right)}, -a \cdot \frac{d}{{\left(\mathsf{hypot}\left(c, d\right)\right)}^{2}}\right)} \]
    5. Taylor expanded in c around inf 93.3%

      \[\leadsto \color{blue}{\frac{b + -1 \cdot \frac{a \cdot d}{c}}{c}} \]
    6. Step-by-step derivation
      1. mul-1-neg93.3%

        \[\leadsto \frac{b + \color{blue}{\left(-\frac{a \cdot d}{c}\right)}}{c} \]
      2. unsub-neg93.3%

        \[\leadsto \frac{\color{blue}{b - \frac{a \cdot d}{c}}}{c} \]
      3. associate-/l*94.5%

        \[\leadsto \frac{b - \color{blue}{a \cdot \frac{d}{c}}}{c} \]
    7. Simplified94.5%

      \[\leadsto \color{blue}{\frac{b - a \cdot \frac{d}{c}}{c}} \]
  3. Recombined 3 regimes into one program.
  4. Final simplification87.8%

    \[\leadsto \begin{array}{l} \mathbf{if}\;d \leq -2.7 \cdot 10^{+84}:\\ \;\;\;\;\frac{\frac{c}{\frac{d}{b}} - a}{d}\\ \mathbf{elif}\;d \leq -2.06 \cdot 10^{-159}:\\ \;\;\;\;\frac{c \cdot b - d \cdot a}{c \cdot c + d \cdot d}\\ \mathbf{elif}\;d \leq 1.4 \cdot 10^{-97}:\\ \;\;\;\;\frac{b - a \cdot \frac{d}{c}}{c}\\ \mathbf{elif}\;d \leq 6.7 \cdot 10^{+93}:\\ \;\;\;\;\frac{c \cdot b - d \cdot a}{c \cdot c + d \cdot d}\\ \mathbf{else}:\\ \;\;\;\;\frac{\frac{c}{\frac{d}{b}} - a}{d}\\ \end{array} \]
  5. Add Preprocessing

Alternative 4: 77.4% accurate, 0.8× speedup?

\[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;d \leq -1.6 \cdot 10^{+84} \lor \neg \left(d \leq 1.85 \cdot 10^{-10}\right):\\ \;\;\;\;\frac{\frac{c}{\frac{d}{b}} - a}{d}\\ \mathbf{else}:\\ \;\;\;\;\frac{b - a \cdot \frac{d}{c}}{c}\\ \end{array} \end{array} \]
(FPCore (a b c d)
 :precision binary64
 (if (or (<= d -1.6e+84) (not (<= d 1.85e-10)))
   (/ (- (/ c (/ d b)) a) d)
   (/ (- b (* a (/ d c))) c)))
double code(double a, double b, double c, double d) {
	double tmp;
	if ((d <= -1.6e+84) || !(d <= 1.85e-10)) {
		tmp = ((c / (d / b)) - a) / d;
	} else {
		tmp = (b - (a * (d / c))) / c;
	}
	return tmp;
}
real(8) function code(a, b, c, d)
    real(8), intent (in) :: a
    real(8), intent (in) :: b
    real(8), intent (in) :: c
    real(8), intent (in) :: d
    real(8) :: tmp
    if ((d <= (-1.6d+84)) .or. (.not. (d <= 1.85d-10))) then
        tmp = ((c / (d / b)) - a) / d
    else
        tmp = (b - (a * (d / c))) / c
    end if
    code = tmp
end function
public static double code(double a, double b, double c, double d) {
	double tmp;
	if ((d <= -1.6e+84) || !(d <= 1.85e-10)) {
		tmp = ((c / (d / b)) - a) / d;
	} else {
		tmp = (b - (a * (d / c))) / c;
	}
	return tmp;
}
def code(a, b, c, d):
	tmp = 0
	if (d <= -1.6e+84) or not (d <= 1.85e-10):
		tmp = ((c / (d / b)) - a) / d
	else:
		tmp = (b - (a * (d / c))) / c
	return tmp
function code(a, b, c, d)
	tmp = 0.0
	if ((d <= -1.6e+84) || !(d <= 1.85e-10))
		tmp = Float64(Float64(Float64(c / Float64(d / b)) - a) / d);
	else
		tmp = Float64(Float64(b - Float64(a * Float64(d / c))) / c);
	end
	return tmp
end
function tmp_2 = code(a, b, c, d)
	tmp = 0.0;
	if ((d <= -1.6e+84) || ~((d <= 1.85e-10)))
		tmp = ((c / (d / b)) - a) / d;
	else
		tmp = (b - (a * (d / c))) / c;
	end
	tmp_2 = tmp;
end
code[a_, b_, c_, d_] := If[Or[LessEqual[d, -1.6e+84], N[Not[LessEqual[d, 1.85e-10]], $MachinePrecision]], N[(N[(N[(c / N[(d / b), $MachinePrecision]), $MachinePrecision] - a), $MachinePrecision] / d), $MachinePrecision], N[(N[(b - N[(a * N[(d / c), $MachinePrecision]), $MachinePrecision]), $MachinePrecision] / c), $MachinePrecision]]
\begin{array}{l}

\\
\begin{array}{l}
\mathbf{if}\;d \leq -1.6 \cdot 10^{+84} \lor \neg \left(d \leq 1.85 \cdot 10^{-10}\right):\\
\;\;\;\;\frac{\frac{c}{\frac{d}{b}} - a}{d}\\

\mathbf{else}:\\
\;\;\;\;\frac{b - a \cdot \frac{d}{c}}{c}\\


\end{array}
\end{array}
Derivation
  1. Split input into 2 regimes
  2. if d < -1.60000000000000005e84 or 1.85000000000000007e-10 < d

    1. Initial program 48.8%

      \[\frac{b \cdot c - a \cdot d}{c \cdot c + d \cdot d} \]
    2. Add Preprocessing
    3. Taylor expanded in c around 0 69.0%

      \[\leadsto \color{blue}{-1 \cdot \frac{a}{d} + \frac{b \cdot c}{{d}^{2}}} \]
    4. Step-by-step derivation
      1. +-commutative69.0%

        \[\leadsto \color{blue}{\frac{b \cdot c}{{d}^{2}} + -1 \cdot \frac{a}{d}} \]
      2. mul-1-neg69.0%

        \[\leadsto \frac{b \cdot c}{{d}^{2}} + \color{blue}{\left(-\frac{a}{d}\right)} \]
      3. unsub-neg69.0%

        \[\leadsto \color{blue}{\frac{b \cdot c}{{d}^{2}} - \frac{a}{d}} \]
      4. unpow269.0%

        \[\leadsto \frac{b \cdot c}{\color{blue}{d \cdot d}} - \frac{a}{d} \]
      5. associate-/r*74.2%

        \[\leadsto \color{blue}{\frac{\frac{b \cdot c}{d}}{d}} - \frac{a}{d} \]
      6. div-sub74.2%

        \[\leadsto \color{blue}{\frac{\frac{b \cdot c}{d} - a}{d}} \]
      7. *-commutative74.2%

        \[\leadsto \frac{\frac{\color{blue}{c \cdot b}}{d} - a}{d} \]
      8. associate-/l*79.6%

        \[\leadsto \frac{\color{blue}{c \cdot \frac{b}{d}} - a}{d} \]
    5. Simplified79.6%

      \[\leadsto \color{blue}{\frac{c \cdot \frac{b}{d} - a}{d}} \]
    6. Step-by-step derivation
      1. clear-num79.6%

        \[\leadsto \frac{c \cdot \color{blue}{\frac{1}{\frac{d}{b}}} - a}{d} \]
      2. un-div-inv79.6%

        \[\leadsto \frac{\color{blue}{\frac{c}{\frac{d}{b}}} - a}{d} \]
    7. Applied egg-rr79.6%

      \[\leadsto \frac{\color{blue}{\frac{c}{\frac{d}{b}}} - a}{d} \]

    if -1.60000000000000005e84 < d < 1.85000000000000007e-10

    1. Initial program 77.1%

      \[\frac{b \cdot c - a \cdot d}{c \cdot c + d \cdot d} \]
    2. Add Preprocessing
    3. Step-by-step derivation
      1. div-sub74.1%

        \[\leadsto \color{blue}{\frac{b \cdot c}{c \cdot c + d \cdot d} - \frac{a \cdot d}{c \cdot c + d \cdot d}} \]
      2. *-commutative74.1%

        \[\leadsto \frac{\color{blue}{c \cdot b}}{c \cdot c + d \cdot d} - \frac{a \cdot d}{c \cdot c + d \cdot d} \]
      3. fma-define74.1%

        \[\leadsto \frac{c \cdot b}{\color{blue}{\mathsf{fma}\left(c, c, d \cdot d\right)}} - \frac{a \cdot d}{c \cdot c + d \cdot d} \]
      4. add-sqr-sqrt74.1%

        \[\leadsto \frac{c \cdot b}{\color{blue}{\sqrt{\mathsf{fma}\left(c, c, d \cdot d\right)} \cdot \sqrt{\mathsf{fma}\left(c, c, d \cdot d\right)}}} - \frac{a \cdot d}{c \cdot c + d \cdot d} \]
      5. times-frac76.5%

        \[\leadsto \color{blue}{\frac{c}{\sqrt{\mathsf{fma}\left(c, c, d \cdot d\right)}} \cdot \frac{b}{\sqrt{\mathsf{fma}\left(c, c, d \cdot d\right)}}} - \frac{a \cdot d}{c \cdot c + d \cdot d} \]
      6. fma-neg76.5%

        \[\leadsto \color{blue}{\mathsf{fma}\left(\frac{c}{\sqrt{\mathsf{fma}\left(c, c, d \cdot d\right)}}, \frac{b}{\sqrt{\mathsf{fma}\left(c, c, d \cdot d\right)}}, -\frac{a \cdot d}{c \cdot c + d \cdot d}\right)} \]
      7. fma-define76.5%

        \[\leadsto \mathsf{fma}\left(\frac{c}{\sqrt{\color{blue}{c \cdot c + d \cdot d}}}, \frac{b}{\sqrt{\mathsf{fma}\left(c, c, d \cdot d\right)}}, -\frac{a \cdot d}{c \cdot c + d \cdot d}\right) \]
      8. hypot-define76.5%

        \[\leadsto \mathsf{fma}\left(\frac{c}{\color{blue}{\mathsf{hypot}\left(c, d\right)}}, \frac{b}{\sqrt{\mathsf{fma}\left(c, c, d \cdot d\right)}}, -\frac{a \cdot d}{c \cdot c + d \cdot d}\right) \]
      9. fma-define76.5%

        \[\leadsto \mathsf{fma}\left(\frac{c}{\mathsf{hypot}\left(c, d\right)}, \frac{b}{\sqrt{\color{blue}{c \cdot c + d \cdot d}}}, -\frac{a \cdot d}{c \cdot c + d \cdot d}\right) \]
      10. hypot-define91.1%

        \[\leadsto \mathsf{fma}\left(\frac{c}{\mathsf{hypot}\left(c, d\right)}, \frac{b}{\color{blue}{\mathsf{hypot}\left(c, d\right)}}, -\frac{a \cdot d}{c \cdot c + d \cdot d}\right) \]
      11. associate-/l*91.3%

        \[\leadsto \mathsf{fma}\left(\frac{c}{\mathsf{hypot}\left(c, d\right)}, \frac{b}{\mathsf{hypot}\left(c, d\right)}, -\color{blue}{a \cdot \frac{d}{c \cdot c + d \cdot d}}\right) \]
      12. fma-define91.3%

        \[\leadsto \mathsf{fma}\left(\frac{c}{\mathsf{hypot}\left(c, d\right)}, \frac{b}{\mathsf{hypot}\left(c, d\right)}, -a \cdot \frac{d}{\color{blue}{\mathsf{fma}\left(c, c, d \cdot d\right)}}\right) \]
      13. add-sqr-sqrt91.3%

        \[\leadsto \mathsf{fma}\left(\frac{c}{\mathsf{hypot}\left(c, d\right)}, \frac{b}{\mathsf{hypot}\left(c, d\right)}, -a \cdot \frac{d}{\color{blue}{\sqrt{\mathsf{fma}\left(c, c, d \cdot d\right)} \cdot \sqrt{\mathsf{fma}\left(c, c, d \cdot d\right)}}}\right) \]
      14. pow291.3%

        \[\leadsto \mathsf{fma}\left(\frac{c}{\mathsf{hypot}\left(c, d\right)}, \frac{b}{\mathsf{hypot}\left(c, d\right)}, -a \cdot \frac{d}{\color{blue}{{\left(\sqrt{\mathsf{fma}\left(c, c, d \cdot d\right)}\right)}^{2}}}\right) \]
    4. Applied egg-rr91.3%

      \[\leadsto \color{blue}{\mathsf{fma}\left(\frac{c}{\mathsf{hypot}\left(c, d\right)}, \frac{b}{\mathsf{hypot}\left(c, d\right)}, -a \cdot \frac{d}{{\left(\mathsf{hypot}\left(c, d\right)\right)}^{2}}\right)} \]
    5. Taylor expanded in c around inf 84.9%

      \[\leadsto \color{blue}{\frac{b + -1 \cdot \frac{a \cdot d}{c}}{c}} \]
    6. Step-by-step derivation
      1. mul-1-neg84.9%

        \[\leadsto \frac{b + \color{blue}{\left(-\frac{a \cdot d}{c}\right)}}{c} \]
      2. unsub-neg84.9%

        \[\leadsto \frac{\color{blue}{b - \frac{a \cdot d}{c}}}{c} \]
      3. associate-/l*85.6%

        \[\leadsto \frac{b - \color{blue}{a \cdot \frac{d}{c}}}{c} \]
    7. Simplified85.6%

      \[\leadsto \color{blue}{\frac{b - a \cdot \frac{d}{c}}{c}} \]
  3. Recombined 2 regimes into one program.
  4. Final simplification83.0%

    \[\leadsto \begin{array}{l} \mathbf{if}\;d \leq -1.6 \cdot 10^{+84} \lor \neg \left(d \leq 1.85 \cdot 10^{-10}\right):\\ \;\;\;\;\frac{\frac{c}{\frac{d}{b}} - a}{d}\\ \mathbf{else}:\\ \;\;\;\;\frac{b - a \cdot \frac{d}{c}}{c}\\ \end{array} \]
  5. Add Preprocessing

Alternative 5: 77.3% accurate, 0.8× speedup?

\[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;d \leq -2 \cdot 10^{+88} \lor \neg \left(d \leq 1.9 \cdot 10^{-10}\right):\\ \;\;\;\;\frac{c \cdot \frac{b}{d} - a}{d}\\ \mathbf{else}:\\ \;\;\;\;\frac{b - a \cdot \frac{d}{c}}{c}\\ \end{array} \end{array} \]
(FPCore (a b c d)
 :precision binary64
 (if (or (<= d -2e+88) (not (<= d 1.9e-10)))
   (/ (- (* c (/ b d)) a) d)
   (/ (- b (* a (/ d c))) c)))
double code(double a, double b, double c, double d) {
	double tmp;
	if ((d <= -2e+88) || !(d <= 1.9e-10)) {
		tmp = ((c * (b / d)) - a) / d;
	} else {
		tmp = (b - (a * (d / c))) / c;
	}
	return tmp;
}
real(8) function code(a, b, c, d)
    real(8), intent (in) :: a
    real(8), intent (in) :: b
    real(8), intent (in) :: c
    real(8), intent (in) :: d
    real(8) :: tmp
    if ((d <= (-2d+88)) .or. (.not. (d <= 1.9d-10))) then
        tmp = ((c * (b / d)) - a) / d
    else
        tmp = (b - (a * (d / c))) / c
    end if
    code = tmp
end function
public static double code(double a, double b, double c, double d) {
	double tmp;
	if ((d <= -2e+88) || !(d <= 1.9e-10)) {
		tmp = ((c * (b / d)) - a) / d;
	} else {
		tmp = (b - (a * (d / c))) / c;
	}
	return tmp;
}
def code(a, b, c, d):
	tmp = 0
	if (d <= -2e+88) or not (d <= 1.9e-10):
		tmp = ((c * (b / d)) - a) / d
	else:
		tmp = (b - (a * (d / c))) / c
	return tmp
function code(a, b, c, d)
	tmp = 0.0
	if ((d <= -2e+88) || !(d <= 1.9e-10))
		tmp = Float64(Float64(Float64(c * Float64(b / d)) - a) / d);
	else
		tmp = Float64(Float64(b - Float64(a * Float64(d / c))) / c);
	end
	return tmp
end
function tmp_2 = code(a, b, c, d)
	tmp = 0.0;
	if ((d <= -2e+88) || ~((d <= 1.9e-10)))
		tmp = ((c * (b / d)) - a) / d;
	else
		tmp = (b - (a * (d / c))) / c;
	end
	tmp_2 = tmp;
end
code[a_, b_, c_, d_] := If[Or[LessEqual[d, -2e+88], N[Not[LessEqual[d, 1.9e-10]], $MachinePrecision]], N[(N[(N[(c * N[(b / d), $MachinePrecision]), $MachinePrecision] - a), $MachinePrecision] / d), $MachinePrecision], N[(N[(b - N[(a * N[(d / c), $MachinePrecision]), $MachinePrecision]), $MachinePrecision] / c), $MachinePrecision]]
\begin{array}{l}

\\
\begin{array}{l}
\mathbf{if}\;d \leq -2 \cdot 10^{+88} \lor \neg \left(d \leq 1.9 \cdot 10^{-10}\right):\\
\;\;\;\;\frac{c \cdot \frac{b}{d} - a}{d}\\

\mathbf{else}:\\
\;\;\;\;\frac{b - a \cdot \frac{d}{c}}{c}\\


\end{array}
\end{array}
Derivation
  1. Split input into 2 regimes
  2. if d < -1.99999999999999992e88 or 1.8999999999999999e-10 < d

    1. Initial program 48.8%

      \[\frac{b \cdot c - a \cdot d}{c \cdot c + d \cdot d} \]
    2. Add Preprocessing
    3. Taylor expanded in c around 0 69.0%

      \[\leadsto \color{blue}{-1 \cdot \frac{a}{d} + \frac{b \cdot c}{{d}^{2}}} \]
    4. Step-by-step derivation
      1. +-commutative69.0%

        \[\leadsto \color{blue}{\frac{b \cdot c}{{d}^{2}} + -1 \cdot \frac{a}{d}} \]
      2. mul-1-neg69.0%

        \[\leadsto \frac{b \cdot c}{{d}^{2}} + \color{blue}{\left(-\frac{a}{d}\right)} \]
      3. unsub-neg69.0%

        \[\leadsto \color{blue}{\frac{b \cdot c}{{d}^{2}} - \frac{a}{d}} \]
      4. unpow269.0%

        \[\leadsto \frac{b \cdot c}{\color{blue}{d \cdot d}} - \frac{a}{d} \]
      5. associate-/r*74.2%

        \[\leadsto \color{blue}{\frac{\frac{b \cdot c}{d}}{d}} - \frac{a}{d} \]
      6. div-sub74.2%

        \[\leadsto \color{blue}{\frac{\frac{b \cdot c}{d} - a}{d}} \]
      7. *-commutative74.2%

        \[\leadsto \frac{\frac{\color{blue}{c \cdot b}}{d} - a}{d} \]
      8. associate-/l*79.6%

        \[\leadsto \frac{\color{blue}{c \cdot \frac{b}{d}} - a}{d} \]
    5. Simplified79.6%

      \[\leadsto \color{blue}{\frac{c \cdot \frac{b}{d} - a}{d}} \]

    if -1.99999999999999992e88 < d < 1.8999999999999999e-10

    1. Initial program 77.1%

      \[\frac{b \cdot c - a \cdot d}{c \cdot c + d \cdot d} \]
    2. Add Preprocessing
    3. Step-by-step derivation
      1. div-sub74.1%

        \[\leadsto \color{blue}{\frac{b \cdot c}{c \cdot c + d \cdot d} - \frac{a \cdot d}{c \cdot c + d \cdot d}} \]
      2. *-commutative74.1%

        \[\leadsto \frac{\color{blue}{c \cdot b}}{c \cdot c + d \cdot d} - \frac{a \cdot d}{c \cdot c + d \cdot d} \]
      3. fma-define74.1%

        \[\leadsto \frac{c \cdot b}{\color{blue}{\mathsf{fma}\left(c, c, d \cdot d\right)}} - \frac{a \cdot d}{c \cdot c + d \cdot d} \]
      4. add-sqr-sqrt74.1%

        \[\leadsto \frac{c \cdot b}{\color{blue}{\sqrt{\mathsf{fma}\left(c, c, d \cdot d\right)} \cdot \sqrt{\mathsf{fma}\left(c, c, d \cdot d\right)}}} - \frac{a \cdot d}{c \cdot c + d \cdot d} \]
      5. times-frac76.5%

        \[\leadsto \color{blue}{\frac{c}{\sqrt{\mathsf{fma}\left(c, c, d \cdot d\right)}} \cdot \frac{b}{\sqrt{\mathsf{fma}\left(c, c, d \cdot d\right)}}} - \frac{a \cdot d}{c \cdot c + d \cdot d} \]
      6. fma-neg76.5%

        \[\leadsto \color{blue}{\mathsf{fma}\left(\frac{c}{\sqrt{\mathsf{fma}\left(c, c, d \cdot d\right)}}, \frac{b}{\sqrt{\mathsf{fma}\left(c, c, d \cdot d\right)}}, -\frac{a \cdot d}{c \cdot c + d \cdot d}\right)} \]
      7. fma-define76.5%

        \[\leadsto \mathsf{fma}\left(\frac{c}{\sqrt{\color{blue}{c \cdot c + d \cdot d}}}, \frac{b}{\sqrt{\mathsf{fma}\left(c, c, d \cdot d\right)}}, -\frac{a \cdot d}{c \cdot c + d \cdot d}\right) \]
      8. hypot-define76.5%

        \[\leadsto \mathsf{fma}\left(\frac{c}{\color{blue}{\mathsf{hypot}\left(c, d\right)}}, \frac{b}{\sqrt{\mathsf{fma}\left(c, c, d \cdot d\right)}}, -\frac{a \cdot d}{c \cdot c + d \cdot d}\right) \]
      9. fma-define76.5%

        \[\leadsto \mathsf{fma}\left(\frac{c}{\mathsf{hypot}\left(c, d\right)}, \frac{b}{\sqrt{\color{blue}{c \cdot c + d \cdot d}}}, -\frac{a \cdot d}{c \cdot c + d \cdot d}\right) \]
      10. hypot-define91.1%

        \[\leadsto \mathsf{fma}\left(\frac{c}{\mathsf{hypot}\left(c, d\right)}, \frac{b}{\color{blue}{\mathsf{hypot}\left(c, d\right)}}, -\frac{a \cdot d}{c \cdot c + d \cdot d}\right) \]
      11. associate-/l*91.3%

        \[\leadsto \mathsf{fma}\left(\frac{c}{\mathsf{hypot}\left(c, d\right)}, \frac{b}{\mathsf{hypot}\left(c, d\right)}, -\color{blue}{a \cdot \frac{d}{c \cdot c + d \cdot d}}\right) \]
      12. fma-define91.3%

        \[\leadsto \mathsf{fma}\left(\frac{c}{\mathsf{hypot}\left(c, d\right)}, \frac{b}{\mathsf{hypot}\left(c, d\right)}, -a \cdot \frac{d}{\color{blue}{\mathsf{fma}\left(c, c, d \cdot d\right)}}\right) \]
      13. add-sqr-sqrt91.3%

        \[\leadsto \mathsf{fma}\left(\frac{c}{\mathsf{hypot}\left(c, d\right)}, \frac{b}{\mathsf{hypot}\left(c, d\right)}, -a \cdot \frac{d}{\color{blue}{\sqrt{\mathsf{fma}\left(c, c, d \cdot d\right)} \cdot \sqrt{\mathsf{fma}\left(c, c, d \cdot d\right)}}}\right) \]
      14. pow291.3%

        \[\leadsto \mathsf{fma}\left(\frac{c}{\mathsf{hypot}\left(c, d\right)}, \frac{b}{\mathsf{hypot}\left(c, d\right)}, -a \cdot \frac{d}{\color{blue}{{\left(\sqrt{\mathsf{fma}\left(c, c, d \cdot d\right)}\right)}^{2}}}\right) \]
    4. Applied egg-rr91.3%

      \[\leadsto \color{blue}{\mathsf{fma}\left(\frac{c}{\mathsf{hypot}\left(c, d\right)}, \frac{b}{\mathsf{hypot}\left(c, d\right)}, -a \cdot \frac{d}{{\left(\mathsf{hypot}\left(c, d\right)\right)}^{2}}\right)} \]
    5. Taylor expanded in c around inf 84.9%

      \[\leadsto \color{blue}{\frac{b + -1 \cdot \frac{a \cdot d}{c}}{c}} \]
    6. Step-by-step derivation
      1. mul-1-neg84.9%

        \[\leadsto \frac{b + \color{blue}{\left(-\frac{a \cdot d}{c}\right)}}{c} \]
      2. unsub-neg84.9%

        \[\leadsto \frac{\color{blue}{b - \frac{a \cdot d}{c}}}{c} \]
      3. associate-/l*85.6%

        \[\leadsto \frac{b - \color{blue}{a \cdot \frac{d}{c}}}{c} \]
    7. Simplified85.6%

      \[\leadsto \color{blue}{\frac{b - a \cdot \frac{d}{c}}{c}} \]
  3. Recombined 2 regimes into one program.
  4. Final simplification82.9%

    \[\leadsto \begin{array}{l} \mathbf{if}\;d \leq -2 \cdot 10^{+88} \lor \neg \left(d \leq 1.9 \cdot 10^{-10}\right):\\ \;\;\;\;\frac{c \cdot \frac{b}{d} - a}{d}\\ \mathbf{else}:\\ \;\;\;\;\frac{b - a \cdot \frac{d}{c}}{c}\\ \end{array} \]
  5. Add Preprocessing

Alternative 6: 72.3% accurate, 0.8× speedup?

\[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;d \leq -6.6 \cdot 10^{+93} \lor \neg \left(d \leq 4 \cdot 10^{+96}\right):\\ \;\;\;\;\frac{-a}{d}\\ \mathbf{else}:\\ \;\;\;\;\frac{b - a \cdot \frac{d}{c}}{c}\\ \end{array} \end{array} \]
(FPCore (a b c d)
 :precision binary64
 (if (or (<= d -6.6e+93) (not (<= d 4e+96)))
   (/ (- a) d)
   (/ (- b (* a (/ d c))) c)))
double code(double a, double b, double c, double d) {
	double tmp;
	if ((d <= -6.6e+93) || !(d <= 4e+96)) {
		tmp = -a / d;
	} else {
		tmp = (b - (a * (d / c))) / c;
	}
	return tmp;
}
real(8) function code(a, b, c, d)
    real(8), intent (in) :: a
    real(8), intent (in) :: b
    real(8), intent (in) :: c
    real(8), intent (in) :: d
    real(8) :: tmp
    if ((d <= (-6.6d+93)) .or. (.not. (d <= 4d+96))) then
        tmp = -a / d
    else
        tmp = (b - (a * (d / c))) / c
    end if
    code = tmp
end function
public static double code(double a, double b, double c, double d) {
	double tmp;
	if ((d <= -6.6e+93) || !(d <= 4e+96)) {
		tmp = -a / d;
	} else {
		tmp = (b - (a * (d / c))) / c;
	}
	return tmp;
}
def code(a, b, c, d):
	tmp = 0
	if (d <= -6.6e+93) or not (d <= 4e+96):
		tmp = -a / d
	else:
		tmp = (b - (a * (d / c))) / c
	return tmp
function code(a, b, c, d)
	tmp = 0.0
	if ((d <= -6.6e+93) || !(d <= 4e+96))
		tmp = Float64(Float64(-a) / d);
	else
		tmp = Float64(Float64(b - Float64(a * Float64(d / c))) / c);
	end
	return tmp
end
function tmp_2 = code(a, b, c, d)
	tmp = 0.0;
	if ((d <= -6.6e+93) || ~((d <= 4e+96)))
		tmp = -a / d;
	else
		tmp = (b - (a * (d / c))) / c;
	end
	tmp_2 = tmp;
end
code[a_, b_, c_, d_] := If[Or[LessEqual[d, -6.6e+93], N[Not[LessEqual[d, 4e+96]], $MachinePrecision]], N[((-a) / d), $MachinePrecision], N[(N[(b - N[(a * N[(d / c), $MachinePrecision]), $MachinePrecision]), $MachinePrecision] / c), $MachinePrecision]]
\begin{array}{l}

\\
\begin{array}{l}
\mathbf{if}\;d \leq -6.6 \cdot 10^{+93} \lor \neg \left(d \leq 4 \cdot 10^{+96}\right):\\
\;\;\;\;\frac{-a}{d}\\

\mathbf{else}:\\
\;\;\;\;\frac{b - a \cdot \frac{d}{c}}{c}\\


\end{array}
\end{array}
Derivation
  1. Split input into 2 regimes
  2. if d < -6.60000000000000017e93 or 4.0000000000000002e96 < d

    1. Initial program 40.0%

      \[\frac{b \cdot c - a \cdot d}{c \cdot c + d \cdot d} \]
    2. Add Preprocessing
    3. Taylor expanded in c around 0 75.1%

      \[\leadsto \color{blue}{-1 \cdot \frac{a}{d}} \]
    4. Step-by-step derivation
      1. associate-*r/75.1%

        \[\leadsto \color{blue}{\frac{-1 \cdot a}{d}} \]
      2. neg-mul-175.1%

        \[\leadsto \frac{\color{blue}{-a}}{d} \]
    5. Simplified75.1%

      \[\leadsto \color{blue}{\frac{-a}{d}} \]

    if -6.60000000000000017e93 < d < 4.0000000000000002e96

    1. Initial program 76.6%

      \[\frac{b \cdot c - a \cdot d}{c \cdot c + d \cdot d} \]
    2. Add Preprocessing
    3. Step-by-step derivation
      1. div-sub74.1%

        \[\leadsto \color{blue}{\frac{b \cdot c}{c \cdot c + d \cdot d} - \frac{a \cdot d}{c \cdot c + d \cdot d}} \]
      2. *-commutative74.1%

        \[\leadsto \frac{\color{blue}{c \cdot b}}{c \cdot c + d \cdot d} - \frac{a \cdot d}{c \cdot c + d \cdot d} \]
      3. fma-define74.1%

        \[\leadsto \frac{c \cdot b}{\color{blue}{\mathsf{fma}\left(c, c, d \cdot d\right)}} - \frac{a \cdot d}{c \cdot c + d \cdot d} \]
      4. add-sqr-sqrt74.1%

        \[\leadsto \frac{c \cdot b}{\color{blue}{\sqrt{\mathsf{fma}\left(c, c, d \cdot d\right)} \cdot \sqrt{\mathsf{fma}\left(c, c, d \cdot d\right)}}} - \frac{a \cdot d}{c \cdot c + d \cdot d} \]
      5. times-frac76.7%

        \[\leadsto \color{blue}{\frac{c}{\sqrt{\mathsf{fma}\left(c, c, d \cdot d\right)}} \cdot \frac{b}{\sqrt{\mathsf{fma}\left(c, c, d \cdot d\right)}}} - \frac{a \cdot d}{c \cdot c + d \cdot d} \]
      6. fma-neg76.7%

        \[\leadsto \color{blue}{\mathsf{fma}\left(\frac{c}{\sqrt{\mathsf{fma}\left(c, c, d \cdot d\right)}}, \frac{b}{\sqrt{\mathsf{fma}\left(c, c, d \cdot d\right)}}, -\frac{a \cdot d}{c \cdot c + d \cdot d}\right)} \]
      7. fma-define76.7%

        \[\leadsto \mathsf{fma}\left(\frac{c}{\sqrt{\color{blue}{c \cdot c + d \cdot d}}}, \frac{b}{\sqrt{\mathsf{fma}\left(c, c, d \cdot d\right)}}, -\frac{a \cdot d}{c \cdot c + d \cdot d}\right) \]
      8. hypot-define76.7%

        \[\leadsto \mathsf{fma}\left(\frac{c}{\color{blue}{\mathsf{hypot}\left(c, d\right)}}, \frac{b}{\sqrt{\mathsf{fma}\left(c, c, d \cdot d\right)}}, -\frac{a \cdot d}{c \cdot c + d \cdot d}\right) \]
      9. fma-define76.7%

        \[\leadsto \mathsf{fma}\left(\frac{c}{\mathsf{hypot}\left(c, d\right)}, \frac{b}{\sqrt{\color{blue}{c \cdot c + d \cdot d}}}, -\frac{a \cdot d}{c \cdot c + d \cdot d}\right) \]
      10. hypot-define90.5%

        \[\leadsto \mathsf{fma}\left(\frac{c}{\mathsf{hypot}\left(c, d\right)}, \frac{b}{\color{blue}{\mathsf{hypot}\left(c, d\right)}}, -\frac{a \cdot d}{c \cdot c + d \cdot d}\right) \]
      11. associate-/l*91.8%

        \[\leadsto \mathsf{fma}\left(\frac{c}{\mathsf{hypot}\left(c, d\right)}, \frac{b}{\mathsf{hypot}\left(c, d\right)}, -\color{blue}{a \cdot \frac{d}{c \cdot c + d \cdot d}}\right) \]
      12. fma-define91.8%

        \[\leadsto \mathsf{fma}\left(\frac{c}{\mathsf{hypot}\left(c, d\right)}, \frac{b}{\mathsf{hypot}\left(c, d\right)}, -a \cdot \frac{d}{\color{blue}{\mathsf{fma}\left(c, c, d \cdot d\right)}}\right) \]
      13. add-sqr-sqrt91.8%

        \[\leadsto \mathsf{fma}\left(\frac{c}{\mathsf{hypot}\left(c, d\right)}, \frac{b}{\mathsf{hypot}\left(c, d\right)}, -a \cdot \frac{d}{\color{blue}{\sqrt{\mathsf{fma}\left(c, c, d \cdot d\right)} \cdot \sqrt{\mathsf{fma}\left(c, c, d \cdot d\right)}}}\right) \]
      14. pow291.8%

        \[\leadsto \mathsf{fma}\left(\frac{c}{\mathsf{hypot}\left(c, d\right)}, \frac{b}{\mathsf{hypot}\left(c, d\right)}, -a \cdot \frac{d}{\color{blue}{{\left(\sqrt{\mathsf{fma}\left(c, c, d \cdot d\right)}\right)}^{2}}}\right) \]
    4. Applied egg-rr91.8%

      \[\leadsto \color{blue}{\mathsf{fma}\left(\frac{c}{\mathsf{hypot}\left(c, d\right)}, \frac{b}{\mathsf{hypot}\left(c, d\right)}, -a \cdot \frac{d}{{\left(\mathsf{hypot}\left(c, d\right)\right)}^{2}}\right)} \]
    5. Taylor expanded in c around inf 77.1%

      \[\leadsto \color{blue}{\frac{b + -1 \cdot \frac{a \cdot d}{c}}{c}} \]
    6. Step-by-step derivation
      1. mul-1-neg77.1%

        \[\leadsto \frac{b + \color{blue}{\left(-\frac{a \cdot d}{c}\right)}}{c} \]
      2. unsub-neg77.1%

        \[\leadsto \frac{\color{blue}{b - \frac{a \cdot d}{c}}}{c} \]
      3. associate-/l*78.8%

        \[\leadsto \frac{b - \color{blue}{a \cdot \frac{d}{c}}}{c} \]
    7. Simplified78.8%

      \[\leadsto \color{blue}{\frac{b - a \cdot \frac{d}{c}}{c}} \]
  3. Recombined 2 regimes into one program.
  4. Final simplification77.6%

    \[\leadsto \begin{array}{l} \mathbf{if}\;d \leq -6.6 \cdot 10^{+93} \lor \neg \left(d \leq 4 \cdot 10^{+96}\right):\\ \;\;\;\;\frac{-a}{d}\\ \mathbf{else}:\\ \;\;\;\;\frac{b - a \cdot \frac{d}{c}}{c}\\ \end{array} \]
  5. Add Preprocessing

Alternative 7: 63.5% accurate, 1.1× speedup?

\[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;d \leq -1.56 \cdot 10^{-78} \lor \neg \left(d \leq 1.8 \cdot 10^{-10}\right):\\ \;\;\;\;\frac{-a}{d}\\ \mathbf{else}:\\ \;\;\;\;\frac{b}{c}\\ \end{array} \end{array} \]
(FPCore (a b c d)
 :precision binary64
 (if (or (<= d -1.56e-78) (not (<= d 1.8e-10))) (/ (- a) d) (/ b c)))
double code(double a, double b, double c, double d) {
	double tmp;
	if ((d <= -1.56e-78) || !(d <= 1.8e-10)) {
		tmp = -a / d;
	} else {
		tmp = b / c;
	}
	return tmp;
}
real(8) function code(a, b, c, d)
    real(8), intent (in) :: a
    real(8), intent (in) :: b
    real(8), intent (in) :: c
    real(8), intent (in) :: d
    real(8) :: tmp
    if ((d <= (-1.56d-78)) .or. (.not. (d <= 1.8d-10))) then
        tmp = -a / d
    else
        tmp = b / c
    end if
    code = tmp
end function
public static double code(double a, double b, double c, double d) {
	double tmp;
	if ((d <= -1.56e-78) || !(d <= 1.8e-10)) {
		tmp = -a / d;
	} else {
		tmp = b / c;
	}
	return tmp;
}
def code(a, b, c, d):
	tmp = 0
	if (d <= -1.56e-78) or not (d <= 1.8e-10):
		tmp = -a / d
	else:
		tmp = b / c
	return tmp
function code(a, b, c, d)
	tmp = 0.0
	if ((d <= -1.56e-78) || !(d <= 1.8e-10))
		tmp = Float64(Float64(-a) / d);
	else
		tmp = Float64(b / c);
	end
	return tmp
end
function tmp_2 = code(a, b, c, d)
	tmp = 0.0;
	if ((d <= -1.56e-78) || ~((d <= 1.8e-10)))
		tmp = -a / d;
	else
		tmp = b / c;
	end
	tmp_2 = tmp;
end
code[a_, b_, c_, d_] := If[Or[LessEqual[d, -1.56e-78], N[Not[LessEqual[d, 1.8e-10]], $MachinePrecision]], N[((-a) / d), $MachinePrecision], N[(b / c), $MachinePrecision]]
\begin{array}{l}

\\
\begin{array}{l}
\mathbf{if}\;d \leq -1.56 \cdot 10^{-78} \lor \neg \left(d \leq 1.8 \cdot 10^{-10}\right):\\
\;\;\;\;\frac{-a}{d}\\

\mathbf{else}:\\
\;\;\;\;\frac{b}{c}\\


\end{array}
\end{array}
Derivation
  1. Split input into 2 regimes
  2. if d < -1.56000000000000002e-78 or 1.8e-10 < d

    1. Initial program 55.2%

      \[\frac{b \cdot c - a \cdot d}{c \cdot c + d \cdot d} \]
    2. Add Preprocessing
    3. Taylor expanded in c around 0 62.1%

      \[\leadsto \color{blue}{-1 \cdot \frac{a}{d}} \]
    4. Step-by-step derivation
      1. associate-*r/62.1%

        \[\leadsto \color{blue}{\frac{-1 \cdot a}{d}} \]
      2. neg-mul-162.1%

        \[\leadsto \frac{\color{blue}{-a}}{d} \]
    5. Simplified62.1%

      \[\leadsto \color{blue}{\frac{-a}{d}} \]

    if -1.56000000000000002e-78 < d < 1.8e-10

    1. Initial program 76.7%

      \[\frac{b \cdot c - a \cdot d}{c \cdot c + d \cdot d} \]
    2. Add Preprocessing
    3. Taylor expanded in c around inf 73.2%

      \[\leadsto \color{blue}{\frac{b}{c}} \]
  3. Recombined 2 regimes into one program.
  4. Final simplification67.0%

    \[\leadsto \begin{array}{l} \mathbf{if}\;d \leq -1.56 \cdot 10^{-78} \lor \neg \left(d \leq 1.8 \cdot 10^{-10}\right):\\ \;\;\;\;\frac{-a}{d}\\ \mathbf{else}:\\ \;\;\;\;\frac{b}{c}\\ \end{array} \]
  5. Add Preprocessing

Alternative 8: 42.4% accurate, 5.0× speedup?

\[\begin{array}{l} \\ \frac{b}{c} \end{array} \]
(FPCore (a b c d) :precision binary64 (/ b c))
double code(double a, double b, double c, double d) {
	return b / c;
}
real(8) function code(a, b, c, d)
    real(8), intent (in) :: a
    real(8), intent (in) :: b
    real(8), intent (in) :: c
    real(8), intent (in) :: d
    code = b / c
end function
public static double code(double a, double b, double c, double d) {
	return b / c;
}
def code(a, b, c, d):
	return b / c
function code(a, b, c, d)
	return Float64(b / c)
end
function tmp = code(a, b, c, d)
	tmp = b / c;
end
code[a_, b_, c_, d_] := N[(b / c), $MachinePrecision]
\begin{array}{l}

\\
\frac{b}{c}
\end{array}
Derivation
  1. Initial program 64.7%

    \[\frac{b \cdot c - a \cdot d}{c \cdot c + d \cdot d} \]
  2. Add Preprocessing
  3. Taylor expanded in c around inf 44.5%

    \[\leadsto \color{blue}{\frac{b}{c}} \]
  4. Add Preprocessing

Developer target: 99.4% accurate, 0.1× speedup?

\[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;\left|d\right| < \left|c\right|:\\ \;\;\;\;\frac{b - a \cdot \frac{d}{c}}{c + d \cdot \frac{d}{c}}\\ \mathbf{else}:\\ \;\;\;\;\frac{\left(-a\right) + b \cdot \frac{c}{d}}{d + c \cdot \frac{c}{d}}\\ \end{array} \end{array} \]
(FPCore (a b c d)
 :precision binary64
 (if (< (fabs d) (fabs c))
   (/ (- b (* a (/ d c))) (+ c (* d (/ d c))))
   (/ (+ (- a) (* b (/ c d))) (+ d (* c (/ c d))))))
double code(double a, double b, double c, double d) {
	double tmp;
	if (fabs(d) < fabs(c)) {
		tmp = (b - (a * (d / c))) / (c + (d * (d / c)));
	} else {
		tmp = (-a + (b * (c / d))) / (d + (c * (c / d)));
	}
	return tmp;
}
real(8) function code(a, b, c, d)
    real(8), intent (in) :: a
    real(8), intent (in) :: b
    real(8), intent (in) :: c
    real(8), intent (in) :: d
    real(8) :: tmp
    if (abs(d) < abs(c)) then
        tmp = (b - (a * (d / c))) / (c + (d * (d / c)))
    else
        tmp = (-a + (b * (c / d))) / (d + (c * (c / d)))
    end if
    code = tmp
end function
public static double code(double a, double b, double c, double d) {
	double tmp;
	if (Math.abs(d) < Math.abs(c)) {
		tmp = (b - (a * (d / c))) / (c + (d * (d / c)));
	} else {
		tmp = (-a + (b * (c / d))) / (d + (c * (c / d)));
	}
	return tmp;
}
def code(a, b, c, d):
	tmp = 0
	if math.fabs(d) < math.fabs(c):
		tmp = (b - (a * (d / c))) / (c + (d * (d / c)))
	else:
		tmp = (-a + (b * (c / d))) / (d + (c * (c / d)))
	return tmp
function code(a, b, c, d)
	tmp = 0.0
	if (abs(d) < abs(c))
		tmp = Float64(Float64(b - Float64(a * Float64(d / c))) / Float64(c + Float64(d * Float64(d / c))));
	else
		tmp = Float64(Float64(Float64(-a) + Float64(b * Float64(c / d))) / Float64(d + Float64(c * Float64(c / d))));
	end
	return tmp
end
function tmp_2 = code(a, b, c, d)
	tmp = 0.0;
	if (abs(d) < abs(c))
		tmp = (b - (a * (d / c))) / (c + (d * (d / c)));
	else
		tmp = (-a + (b * (c / d))) / (d + (c * (c / d)));
	end
	tmp_2 = tmp;
end
code[a_, b_, c_, d_] := If[Less[N[Abs[d], $MachinePrecision], N[Abs[c], $MachinePrecision]], N[(N[(b - N[(a * N[(d / c), $MachinePrecision]), $MachinePrecision]), $MachinePrecision] / N[(c + N[(d * N[(d / c), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision], N[(N[((-a) + N[(b * N[(c / d), $MachinePrecision]), $MachinePrecision]), $MachinePrecision] / N[(d + N[(c * N[(c / d), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]]
\begin{array}{l}

\\
\begin{array}{l}
\mathbf{if}\;\left|d\right| < \left|c\right|:\\
\;\;\;\;\frac{b - a \cdot \frac{d}{c}}{c + d \cdot \frac{d}{c}}\\

\mathbf{else}:\\
\;\;\;\;\frac{\left(-a\right) + b \cdot \frac{c}{d}}{d + c \cdot \frac{c}{d}}\\


\end{array}
\end{array}

Reproduce

?
herbie shell --seed 2024084 
(FPCore (a b c d)
  :name "Complex division, imag part"
  :precision binary64

  :alt
  (if (< (fabs d) (fabs c)) (/ (- b (* a (/ d c))) (+ c (* d (/ d c)))) (/ (+ (- a) (* b (/ c d))) (+ d (* c (/ c d)))))

  (/ (- (* b c) (* a d)) (+ (* c c) (* d d))))