Quotient of products

Percentage Accurate: 85.9% → 97.1%
Time: 4.1s
Alternatives: 9
Speedup: 1.0×

Specification

?
\[\begin{array}{l} \\ \frac{a1 \cdot a2}{b1 \cdot b2} \end{array} \]
(FPCore (a1 a2 b1 b2) :precision binary64 (/ (* a1 a2) (* b1 b2)))
double code(double a1, double a2, double b1, double b2) {
	return (a1 * a2) / (b1 * b2);
}
real(8) function code(a1, a2, b1, b2)
    real(8), intent (in) :: a1
    real(8), intent (in) :: a2
    real(8), intent (in) :: b1
    real(8), intent (in) :: b2
    code = (a1 * a2) / (b1 * b2)
end function
public static double code(double a1, double a2, double b1, double b2) {
	return (a1 * a2) / (b1 * b2);
}
def code(a1, a2, b1, b2):
	return (a1 * a2) / (b1 * b2)
function code(a1, a2, b1, b2)
	return Float64(Float64(a1 * a2) / Float64(b1 * b2))
end
function tmp = code(a1, a2, b1, b2)
	tmp = (a1 * a2) / (b1 * b2);
end
code[a1_, a2_, b1_, b2_] := N[(N[(a1 * a2), $MachinePrecision] / N[(b1 * b2), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}

\\
\frac{a1 \cdot a2}{b1 \cdot b2}
\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 9 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: 85.9% accurate, 1.0× speedup?

\[\begin{array}{l} \\ \frac{a1 \cdot a2}{b1 \cdot b2} \end{array} \]
(FPCore (a1 a2 b1 b2) :precision binary64 (/ (* a1 a2) (* b1 b2)))
double code(double a1, double a2, double b1, double b2) {
	return (a1 * a2) / (b1 * b2);
}
real(8) function code(a1, a2, b1, b2)
    real(8), intent (in) :: a1
    real(8), intent (in) :: a2
    real(8), intent (in) :: b1
    real(8), intent (in) :: b2
    code = (a1 * a2) / (b1 * b2)
end function
public static double code(double a1, double a2, double b1, double b2) {
	return (a1 * a2) / (b1 * b2);
}
def code(a1, a2, b1, b2):
	return (a1 * a2) / (b1 * b2)
function code(a1, a2, b1, b2)
	return Float64(Float64(a1 * a2) / Float64(b1 * b2))
end
function tmp = code(a1, a2, b1, b2)
	tmp = (a1 * a2) / (b1 * b2);
end
code[a1_, a2_, b1_, b2_] := N[(N[(a1 * a2), $MachinePrecision] / N[(b1 * b2), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}

\\
\frac{a1 \cdot a2}{b1 \cdot b2}
\end{array}

Alternative 1: 97.1% accurate, 0.2× speedup?

\[\begin{array}{l} [a1, a2] = \mathsf{sort}([a1, a2])\\ [b1, b2] = \mathsf{sort}([b1, b2])\\ \\ \begin{array}{l} t_0 := \frac{a2 \cdot a1}{b1 \cdot b2}\\ t_1 := \frac{a2}{b1} \cdot \frac{a1}{b2}\\ \mathbf{if}\;t_0 \leq -\infty:\\ \;\;\;\;t_1\\ \mathbf{elif}\;t_0 \leq -1 \cdot 10^{-315}:\\ \;\;\;\;t_0\\ \mathbf{elif}\;t_0 \leq 0:\\ \;\;\;\;a1 \cdot \frac{\frac{a2}{b2}}{b1}\\ \mathbf{elif}\;t_0 \leq 5 \cdot 10^{+303}:\\ \;\;\;\;t_0\\ \mathbf{else}:\\ \;\;\;\;t_1\\ \end{array} \end{array} \]
NOTE: a1 and a2 should be sorted in increasing order before calling this function.
NOTE: b1 and b2 should be sorted in increasing order before calling this function.
(FPCore (a1 a2 b1 b2)
 :precision binary64
 (let* ((t_0 (/ (* a2 a1) (* b1 b2))) (t_1 (* (/ a2 b1) (/ a1 b2))))
   (if (<= t_0 (- INFINITY))
     t_1
     (if (<= t_0 -1e-315)
       t_0
       (if (<= t_0 0.0)
         (* a1 (/ (/ a2 b2) b1))
         (if (<= t_0 5e+303) t_0 t_1))))))
assert(a1 < a2);
assert(b1 < b2);
double code(double a1, double a2, double b1, double b2) {
	double t_0 = (a2 * a1) / (b1 * b2);
	double t_1 = (a2 / b1) * (a1 / b2);
	double tmp;
	if (t_0 <= -((double) INFINITY)) {
		tmp = t_1;
	} else if (t_0 <= -1e-315) {
		tmp = t_0;
	} else if (t_0 <= 0.0) {
		tmp = a1 * ((a2 / b2) / b1);
	} else if (t_0 <= 5e+303) {
		tmp = t_0;
	} else {
		tmp = t_1;
	}
	return tmp;
}
assert a1 < a2;
assert b1 < b2;
public static double code(double a1, double a2, double b1, double b2) {
	double t_0 = (a2 * a1) / (b1 * b2);
	double t_1 = (a2 / b1) * (a1 / b2);
	double tmp;
	if (t_0 <= -Double.POSITIVE_INFINITY) {
		tmp = t_1;
	} else if (t_0 <= -1e-315) {
		tmp = t_0;
	} else if (t_0 <= 0.0) {
		tmp = a1 * ((a2 / b2) / b1);
	} else if (t_0 <= 5e+303) {
		tmp = t_0;
	} else {
		tmp = t_1;
	}
	return tmp;
}
[a1, a2] = sort([a1, a2])
[b1, b2] = sort([b1, b2])
def code(a1, a2, b1, b2):
	t_0 = (a2 * a1) / (b1 * b2)
	t_1 = (a2 / b1) * (a1 / b2)
	tmp = 0
	if t_0 <= -math.inf:
		tmp = t_1
	elif t_0 <= -1e-315:
		tmp = t_0
	elif t_0 <= 0.0:
		tmp = a1 * ((a2 / b2) / b1)
	elif t_0 <= 5e+303:
		tmp = t_0
	else:
		tmp = t_1
	return tmp
a1, a2 = sort([a1, a2])
b1, b2 = sort([b1, b2])
function code(a1, a2, b1, b2)
	t_0 = Float64(Float64(a2 * a1) / Float64(b1 * b2))
	t_1 = Float64(Float64(a2 / b1) * Float64(a1 / b2))
	tmp = 0.0
	if (t_0 <= Float64(-Inf))
		tmp = t_1;
	elseif (t_0 <= -1e-315)
		tmp = t_0;
	elseif (t_0 <= 0.0)
		tmp = Float64(a1 * Float64(Float64(a2 / b2) / b1));
	elseif (t_0 <= 5e+303)
		tmp = t_0;
	else
		tmp = t_1;
	end
	return tmp
end
a1, a2 = num2cell(sort([a1, a2])){:}
b1, b2 = num2cell(sort([b1, b2])){:}
function tmp_2 = code(a1, a2, b1, b2)
	t_0 = (a2 * a1) / (b1 * b2);
	t_1 = (a2 / b1) * (a1 / b2);
	tmp = 0.0;
	if (t_0 <= -Inf)
		tmp = t_1;
	elseif (t_0 <= -1e-315)
		tmp = t_0;
	elseif (t_0 <= 0.0)
		tmp = a1 * ((a2 / b2) / b1);
	elseif (t_0 <= 5e+303)
		tmp = t_0;
	else
		tmp = t_1;
	end
	tmp_2 = tmp;
end
NOTE: a1 and a2 should be sorted in increasing order before calling this function.
NOTE: b1 and b2 should be sorted in increasing order before calling this function.
code[a1_, a2_, b1_, b2_] := Block[{t$95$0 = N[(N[(a2 * a1), $MachinePrecision] / N[(b1 * b2), $MachinePrecision]), $MachinePrecision]}, Block[{t$95$1 = N[(N[(a2 / b1), $MachinePrecision] * N[(a1 / b2), $MachinePrecision]), $MachinePrecision]}, If[LessEqual[t$95$0, (-Infinity)], t$95$1, If[LessEqual[t$95$0, -1e-315], t$95$0, If[LessEqual[t$95$0, 0.0], N[(a1 * N[(N[(a2 / b2), $MachinePrecision] / b1), $MachinePrecision]), $MachinePrecision], If[LessEqual[t$95$0, 5e+303], t$95$0, t$95$1]]]]]]
\begin{array}{l}
[a1, a2] = \mathsf{sort}([a1, a2])\\
[b1, b2] = \mathsf{sort}([b1, b2])\\
\\
\begin{array}{l}
t_0 := \frac{a2 \cdot a1}{b1 \cdot b2}\\
t_1 := \frac{a2}{b1} \cdot \frac{a1}{b2}\\
\mathbf{if}\;t_0 \leq -\infty:\\
\;\;\;\;t_1\\

\mathbf{elif}\;t_0 \leq -1 \cdot 10^{-315}:\\
\;\;\;\;t_0\\

\mathbf{elif}\;t_0 \leq 0:\\
\;\;\;\;a1 \cdot \frac{\frac{a2}{b2}}{b1}\\

\mathbf{elif}\;t_0 \leq 5 \cdot 10^{+303}:\\
\;\;\;\;t_0\\

\mathbf{else}:\\
\;\;\;\;t_1\\


\end{array}
\end{array}
Derivation
  1. Split input into 3 regimes
  2. if (/.f64 (*.f64 a1 a2) (*.f64 b1 b2)) < -inf.0 or 4.9999999999999997e303 < (/.f64 (*.f64 a1 a2) (*.f64 b1 b2))

    1. Initial program 75.0%

      \[\frac{a1 \cdot a2}{b1 \cdot b2} \]
    2. Step-by-step derivation
      1. *-commutative75.0%

        \[\leadsto \frac{\color{blue}{a2 \cdot a1}}{b1 \cdot b2} \]
      2. times-frac96.2%

        \[\leadsto \color{blue}{\frac{a2}{b1} \cdot \frac{a1}{b2}} \]
    3. Applied egg-rr96.2%

      \[\leadsto \color{blue}{\frac{a2}{b1} \cdot \frac{a1}{b2}} \]

    if -inf.0 < (/.f64 (*.f64 a1 a2) (*.f64 b1 b2)) < -9.999999985e-316 or -0.0 < (/.f64 (*.f64 a1 a2) (*.f64 b1 b2)) < 4.9999999999999997e303

    1. Initial program 99.4%

      \[\frac{a1 \cdot a2}{b1 \cdot b2} \]

    if -9.999999985e-316 < (/.f64 (*.f64 a1 a2) (*.f64 b1 b2)) < -0.0

    1. Initial program 69.0%

      \[\frac{a1 \cdot a2}{b1 \cdot b2} \]
    2. Step-by-step derivation
      1. times-frac94.9%

        \[\leadsto \color{blue}{\frac{a1}{b1} \cdot \frac{a2}{b2}} \]
      2. associate-*l/90.3%

        \[\leadsto \color{blue}{\frac{a1 \cdot \frac{a2}{b2}}{b1}} \]
      3. associate-*r/93.2%

        \[\leadsto \color{blue}{a1 \cdot \frac{\frac{a2}{b2}}{b1}} \]
    3. Simplified93.2%

      \[\leadsto \color{blue}{a1 \cdot \frac{\frac{a2}{b2}}{b1}} \]
  3. Recombined 3 regimes into one program.
  4. Final simplification96.9%

    \[\leadsto \begin{array}{l} \mathbf{if}\;\frac{a2 \cdot a1}{b1 \cdot b2} \leq -\infty:\\ \;\;\;\;\frac{a2}{b1} \cdot \frac{a1}{b2}\\ \mathbf{elif}\;\frac{a2 \cdot a1}{b1 \cdot b2} \leq -1 \cdot 10^{-315}:\\ \;\;\;\;\frac{a2 \cdot a1}{b1 \cdot b2}\\ \mathbf{elif}\;\frac{a2 \cdot a1}{b1 \cdot b2} \leq 0:\\ \;\;\;\;a1 \cdot \frac{\frac{a2}{b2}}{b1}\\ \mathbf{elif}\;\frac{a2 \cdot a1}{b1 \cdot b2} \leq 5 \cdot 10^{+303}:\\ \;\;\;\;\frac{a2 \cdot a1}{b1 \cdot b2}\\ \mathbf{else}:\\ \;\;\;\;\frac{a2}{b1} \cdot \frac{a1}{b2}\\ \end{array} \]

Alternative 2: 91.3% accurate, 0.0× speedup?

\[\begin{array}{l} [a1, a2] = \mathsf{sort}([a1, a2])\\ [b1, b2] = \mathsf{sort}([b1, b2])\\ \\ \begin{array}{l} \mathbf{if}\;b1 \cdot b2 \leq -5 \cdot 10^{+214}:\\ \;\;\;\;\frac{\frac{a2 \cdot \frac{a1}{b1}}{\sqrt{b2}}}{\sqrt{b2}}\\ \mathbf{elif}\;b1 \cdot b2 \leq -5 \cdot 10^{-308} \lor \neg \left(b1 \cdot b2 \leq 5 \cdot 10^{-171}\right):\\ \;\;\;\;a1 \cdot \frac{a2}{b1 \cdot b2}\\ \mathbf{else}:\\ \;\;\;\;\frac{a2}{b1} \cdot \frac{a1}{b2}\\ \end{array} \end{array} \]
NOTE: a1 and a2 should be sorted in increasing order before calling this function.
NOTE: b1 and b2 should be sorted in increasing order before calling this function.
(FPCore (a1 a2 b1 b2)
 :precision binary64
 (if (<= (* b1 b2) -5e+214)
   (/ (/ (* a2 (/ a1 b1)) (sqrt b2)) (sqrt b2))
   (if (or (<= (* b1 b2) -5e-308) (not (<= (* b1 b2) 5e-171)))
     (* a1 (/ a2 (* b1 b2)))
     (* (/ a2 b1) (/ a1 b2)))))
assert(a1 < a2);
assert(b1 < b2);
double code(double a1, double a2, double b1, double b2) {
	double tmp;
	if ((b1 * b2) <= -5e+214) {
		tmp = ((a2 * (a1 / b1)) / sqrt(b2)) / sqrt(b2);
	} else if (((b1 * b2) <= -5e-308) || !((b1 * b2) <= 5e-171)) {
		tmp = a1 * (a2 / (b1 * b2));
	} else {
		tmp = (a2 / b1) * (a1 / b2);
	}
	return tmp;
}
NOTE: a1 and a2 should be sorted in increasing order before calling this function.
NOTE: b1 and b2 should be sorted in increasing order before calling this function.
real(8) function code(a1, a2, b1, b2)
    real(8), intent (in) :: a1
    real(8), intent (in) :: a2
    real(8), intent (in) :: b1
    real(8), intent (in) :: b2
    real(8) :: tmp
    if ((b1 * b2) <= (-5d+214)) then
        tmp = ((a2 * (a1 / b1)) / sqrt(b2)) / sqrt(b2)
    else if (((b1 * b2) <= (-5d-308)) .or. (.not. ((b1 * b2) <= 5d-171))) then
        tmp = a1 * (a2 / (b1 * b2))
    else
        tmp = (a2 / b1) * (a1 / b2)
    end if
    code = tmp
end function
assert a1 < a2;
assert b1 < b2;
public static double code(double a1, double a2, double b1, double b2) {
	double tmp;
	if ((b1 * b2) <= -5e+214) {
		tmp = ((a2 * (a1 / b1)) / Math.sqrt(b2)) / Math.sqrt(b2);
	} else if (((b1 * b2) <= -5e-308) || !((b1 * b2) <= 5e-171)) {
		tmp = a1 * (a2 / (b1 * b2));
	} else {
		tmp = (a2 / b1) * (a1 / b2);
	}
	return tmp;
}
[a1, a2] = sort([a1, a2])
[b1, b2] = sort([b1, b2])
def code(a1, a2, b1, b2):
	tmp = 0
	if (b1 * b2) <= -5e+214:
		tmp = ((a2 * (a1 / b1)) / math.sqrt(b2)) / math.sqrt(b2)
	elif ((b1 * b2) <= -5e-308) or not ((b1 * b2) <= 5e-171):
		tmp = a1 * (a2 / (b1 * b2))
	else:
		tmp = (a2 / b1) * (a1 / b2)
	return tmp
a1, a2 = sort([a1, a2])
b1, b2 = sort([b1, b2])
function code(a1, a2, b1, b2)
	tmp = 0.0
	if (Float64(b1 * b2) <= -5e+214)
		tmp = Float64(Float64(Float64(a2 * Float64(a1 / b1)) / sqrt(b2)) / sqrt(b2));
	elseif ((Float64(b1 * b2) <= -5e-308) || !(Float64(b1 * b2) <= 5e-171))
		tmp = Float64(a1 * Float64(a2 / Float64(b1 * b2)));
	else
		tmp = Float64(Float64(a2 / b1) * Float64(a1 / b2));
	end
	return tmp
end
a1, a2 = num2cell(sort([a1, a2])){:}
b1, b2 = num2cell(sort([b1, b2])){:}
function tmp_2 = code(a1, a2, b1, b2)
	tmp = 0.0;
	if ((b1 * b2) <= -5e+214)
		tmp = ((a2 * (a1 / b1)) / sqrt(b2)) / sqrt(b2);
	elseif (((b1 * b2) <= -5e-308) || ~(((b1 * b2) <= 5e-171)))
		tmp = a1 * (a2 / (b1 * b2));
	else
		tmp = (a2 / b1) * (a1 / b2);
	end
	tmp_2 = tmp;
end
NOTE: a1 and a2 should be sorted in increasing order before calling this function.
NOTE: b1 and b2 should be sorted in increasing order before calling this function.
code[a1_, a2_, b1_, b2_] := If[LessEqual[N[(b1 * b2), $MachinePrecision], -5e+214], N[(N[(N[(a2 * N[(a1 / b1), $MachinePrecision]), $MachinePrecision] / N[Sqrt[b2], $MachinePrecision]), $MachinePrecision] / N[Sqrt[b2], $MachinePrecision]), $MachinePrecision], If[Or[LessEqual[N[(b1 * b2), $MachinePrecision], -5e-308], N[Not[LessEqual[N[(b1 * b2), $MachinePrecision], 5e-171]], $MachinePrecision]], N[(a1 * N[(a2 / N[(b1 * b2), $MachinePrecision]), $MachinePrecision]), $MachinePrecision], N[(N[(a2 / b1), $MachinePrecision] * N[(a1 / b2), $MachinePrecision]), $MachinePrecision]]]
\begin{array}{l}
[a1, a2] = \mathsf{sort}([a1, a2])\\
[b1, b2] = \mathsf{sort}([b1, b2])\\
\\
\begin{array}{l}
\mathbf{if}\;b1 \cdot b2 \leq -5 \cdot 10^{+214}:\\
\;\;\;\;\frac{\frac{a2 \cdot \frac{a1}{b1}}{\sqrt{b2}}}{\sqrt{b2}}\\

\mathbf{elif}\;b1 \cdot b2 \leq -5 \cdot 10^{-308} \lor \neg \left(b1 \cdot b2 \leq 5 \cdot 10^{-171}\right):\\
\;\;\;\;a1 \cdot \frac{a2}{b1 \cdot b2}\\

\mathbf{else}:\\
\;\;\;\;\frac{a2}{b1} \cdot \frac{a1}{b2}\\


\end{array}
\end{array}
Derivation
  1. Split input into 3 regimes
  2. if (*.f64 b1 b2) < -4.99999999999999953e214

    1. Initial program 64.9%

      \[\frac{a1 \cdot a2}{b1 \cdot b2} \]
    2. Step-by-step derivation
      1. times-frac81.0%

        \[\leadsto \color{blue}{\frac{a1}{b1} \cdot \frac{a2}{b2}} \]
      2. associate-*l/92.9%

        \[\leadsto \color{blue}{\frac{a1 \cdot \frac{a2}{b2}}{b1}} \]
      3. associate-*r/83.8%

        \[\leadsto \color{blue}{a1 \cdot \frac{\frac{a2}{b2}}{b1}} \]
    3. Simplified83.8%

      \[\leadsto \color{blue}{a1 \cdot \frac{\frac{a2}{b2}}{b1}} \]
    4. Step-by-step derivation
      1. associate-/l/65.2%

        \[\leadsto a1 \cdot \color{blue}{\frac{a2}{b1 \cdot b2}} \]
      2. associate-*r/64.9%

        \[\leadsto \color{blue}{\frac{a1 \cdot a2}{b1 \cdot b2}} \]
      3. associate-/r*92.5%

        \[\leadsto \color{blue}{\frac{\frac{a1 \cdot a2}{b1}}{b2}} \]
      4. add-sqr-sqrt55.4%

        \[\leadsto \frac{\frac{a1 \cdot a2}{b1}}{\color{blue}{\sqrt{b2} \cdot \sqrt{b2}}} \]
      5. associate-/r*55.4%

        \[\leadsto \color{blue}{\frac{\frac{\frac{a1 \cdot a2}{b1}}{\sqrt{b2}}}{\sqrt{b2}}} \]
      6. associate-*l/50.2%

        \[\leadsto \frac{\frac{\color{blue}{\frac{a1}{b1} \cdot a2}}{\sqrt{b2}}}{\sqrt{b2}} \]
      7. *-commutative50.2%

        \[\leadsto \frac{\frac{\color{blue}{a2 \cdot \frac{a1}{b1}}}{\sqrt{b2}}}{\sqrt{b2}} \]
    5. Applied egg-rr50.2%

      \[\leadsto \color{blue}{\frac{\frac{a2 \cdot \frac{a1}{b1}}{\sqrt{b2}}}{\sqrt{b2}}} \]

    if -4.99999999999999953e214 < (*.f64 b1 b2) < -4.99999999999999955e-308 or 4.99999999999999992e-171 < (*.f64 b1 b2)

    1. Initial program 89.6%

      \[\frac{a1 \cdot a2}{b1 \cdot b2} \]
    2. Step-by-step derivation
      1. *-commutative89.6%

        \[\leadsto \frac{\color{blue}{a2 \cdot a1}}{b1 \cdot b2} \]
      2. associate-*l/96.8%

        \[\leadsto \color{blue}{\frac{a2}{b1 \cdot b2} \cdot a1} \]
      3. *-commutative96.8%

        \[\leadsto \frac{a2}{\color{blue}{b2 \cdot b1}} \cdot a1 \]
    3. Applied egg-rr96.8%

      \[\leadsto \color{blue}{\frac{a2}{b2 \cdot b1} \cdot a1} \]

    if -4.99999999999999955e-308 < (*.f64 b1 b2) < 4.99999999999999992e-171

    1. Initial program 76.2%

      \[\frac{a1 \cdot a2}{b1 \cdot b2} \]
    2. Step-by-step derivation
      1. *-commutative76.2%

        \[\leadsto \frac{\color{blue}{a2 \cdot a1}}{b1 \cdot b2} \]
      2. times-frac92.1%

        \[\leadsto \color{blue}{\frac{a2}{b1} \cdot \frac{a1}{b2}} \]
    3. Applied egg-rr92.1%

      \[\leadsto \color{blue}{\frac{a2}{b1} \cdot \frac{a1}{b2}} \]
  3. Recombined 3 regimes into one program.
  4. Final simplification91.0%

    \[\leadsto \begin{array}{l} \mathbf{if}\;b1 \cdot b2 \leq -5 \cdot 10^{+214}:\\ \;\;\;\;\frac{\frac{a2 \cdot \frac{a1}{b1}}{\sqrt{b2}}}{\sqrt{b2}}\\ \mathbf{elif}\;b1 \cdot b2 \leq -5 \cdot 10^{-308} \lor \neg \left(b1 \cdot b2 \leq 5 \cdot 10^{-171}\right):\\ \;\;\;\;a1 \cdot \frac{a2}{b1 \cdot b2}\\ \mathbf{else}:\\ \;\;\;\;\frac{a2}{b1} \cdot \frac{a1}{b2}\\ \end{array} \]

Alternative 3: 91.2% accurate, 0.4× speedup?

\[\begin{array}{l} [a1, a2] = \mathsf{sort}([a1, a2])\\ [b1, b2] = \mathsf{sort}([b1, b2])\\ \\ \begin{array}{l} \mathbf{if}\;b1 \cdot b2 \leq -1 \cdot 10^{+272}:\\ \;\;\;\;\frac{\frac{a1}{b1}}{\frac{b2}{a2}}\\ \mathbf{elif}\;b1 \cdot b2 \leq -5 \cdot 10^{-308} \lor \neg \left(b1 \cdot b2 \leq 5 \cdot 10^{-171}\right):\\ \;\;\;\;a1 \cdot \frac{a2}{b1 \cdot b2}\\ \mathbf{else}:\\ \;\;\;\;\frac{a2}{b1} \cdot \frac{a1}{b2}\\ \end{array} \end{array} \]
NOTE: a1 and a2 should be sorted in increasing order before calling this function.
NOTE: b1 and b2 should be sorted in increasing order before calling this function.
(FPCore (a1 a2 b1 b2)
 :precision binary64
 (if (<= (* b1 b2) -1e+272)
   (/ (/ a1 b1) (/ b2 a2))
   (if (or (<= (* b1 b2) -5e-308) (not (<= (* b1 b2) 5e-171)))
     (* a1 (/ a2 (* b1 b2)))
     (* (/ a2 b1) (/ a1 b2)))))
assert(a1 < a2);
assert(b1 < b2);
double code(double a1, double a2, double b1, double b2) {
	double tmp;
	if ((b1 * b2) <= -1e+272) {
		tmp = (a1 / b1) / (b2 / a2);
	} else if (((b1 * b2) <= -5e-308) || !((b1 * b2) <= 5e-171)) {
		tmp = a1 * (a2 / (b1 * b2));
	} else {
		tmp = (a2 / b1) * (a1 / b2);
	}
	return tmp;
}
NOTE: a1 and a2 should be sorted in increasing order before calling this function.
NOTE: b1 and b2 should be sorted in increasing order before calling this function.
real(8) function code(a1, a2, b1, b2)
    real(8), intent (in) :: a1
    real(8), intent (in) :: a2
    real(8), intent (in) :: b1
    real(8), intent (in) :: b2
    real(8) :: tmp
    if ((b1 * b2) <= (-1d+272)) then
        tmp = (a1 / b1) / (b2 / a2)
    else if (((b1 * b2) <= (-5d-308)) .or. (.not. ((b1 * b2) <= 5d-171))) then
        tmp = a1 * (a2 / (b1 * b2))
    else
        tmp = (a2 / b1) * (a1 / b2)
    end if
    code = tmp
end function
assert a1 < a2;
assert b1 < b2;
public static double code(double a1, double a2, double b1, double b2) {
	double tmp;
	if ((b1 * b2) <= -1e+272) {
		tmp = (a1 / b1) / (b2 / a2);
	} else if (((b1 * b2) <= -5e-308) || !((b1 * b2) <= 5e-171)) {
		tmp = a1 * (a2 / (b1 * b2));
	} else {
		tmp = (a2 / b1) * (a1 / b2);
	}
	return tmp;
}
[a1, a2] = sort([a1, a2])
[b1, b2] = sort([b1, b2])
def code(a1, a2, b1, b2):
	tmp = 0
	if (b1 * b2) <= -1e+272:
		tmp = (a1 / b1) / (b2 / a2)
	elif ((b1 * b2) <= -5e-308) or not ((b1 * b2) <= 5e-171):
		tmp = a1 * (a2 / (b1 * b2))
	else:
		tmp = (a2 / b1) * (a1 / b2)
	return tmp
a1, a2 = sort([a1, a2])
b1, b2 = sort([b1, b2])
function code(a1, a2, b1, b2)
	tmp = 0.0
	if (Float64(b1 * b2) <= -1e+272)
		tmp = Float64(Float64(a1 / b1) / Float64(b2 / a2));
	elseif ((Float64(b1 * b2) <= -5e-308) || !(Float64(b1 * b2) <= 5e-171))
		tmp = Float64(a1 * Float64(a2 / Float64(b1 * b2)));
	else
		tmp = Float64(Float64(a2 / b1) * Float64(a1 / b2));
	end
	return tmp
end
a1, a2 = num2cell(sort([a1, a2])){:}
b1, b2 = num2cell(sort([b1, b2])){:}
function tmp_2 = code(a1, a2, b1, b2)
	tmp = 0.0;
	if ((b1 * b2) <= -1e+272)
		tmp = (a1 / b1) / (b2 / a2);
	elseif (((b1 * b2) <= -5e-308) || ~(((b1 * b2) <= 5e-171)))
		tmp = a1 * (a2 / (b1 * b2));
	else
		tmp = (a2 / b1) * (a1 / b2);
	end
	tmp_2 = tmp;
end
NOTE: a1 and a2 should be sorted in increasing order before calling this function.
NOTE: b1 and b2 should be sorted in increasing order before calling this function.
code[a1_, a2_, b1_, b2_] := If[LessEqual[N[(b1 * b2), $MachinePrecision], -1e+272], N[(N[(a1 / b1), $MachinePrecision] / N[(b2 / a2), $MachinePrecision]), $MachinePrecision], If[Or[LessEqual[N[(b1 * b2), $MachinePrecision], -5e-308], N[Not[LessEqual[N[(b1 * b2), $MachinePrecision], 5e-171]], $MachinePrecision]], N[(a1 * N[(a2 / N[(b1 * b2), $MachinePrecision]), $MachinePrecision]), $MachinePrecision], N[(N[(a2 / b1), $MachinePrecision] * N[(a1 / b2), $MachinePrecision]), $MachinePrecision]]]
\begin{array}{l}
[a1, a2] = \mathsf{sort}([a1, a2])\\
[b1, b2] = \mathsf{sort}([b1, b2])\\
\\
\begin{array}{l}
\mathbf{if}\;b1 \cdot b2 \leq -1 \cdot 10^{+272}:\\
\;\;\;\;\frac{\frac{a1}{b1}}{\frac{b2}{a2}}\\

\mathbf{elif}\;b1 \cdot b2 \leq -5 \cdot 10^{-308} \lor \neg \left(b1 \cdot b2 \leq 5 \cdot 10^{-171}\right):\\
\;\;\;\;a1 \cdot \frac{a2}{b1 \cdot b2}\\

\mathbf{else}:\\
\;\;\;\;\frac{a2}{b1} \cdot \frac{a1}{b2}\\


\end{array}
\end{array}
Derivation
  1. Split input into 3 regimes
  2. if (*.f64 b1 b2) < -1.0000000000000001e272

    1. Initial program 54.9%

      \[\frac{a1 \cdot a2}{b1 \cdot b2} \]
    2. Step-by-step derivation
      1. times-frac84.2%

        \[\leadsto \color{blue}{\frac{a1}{b1} \cdot \frac{a2}{b2}} \]
      2. associate-*l/95.3%

        \[\leadsto \color{blue}{\frac{a1 \cdot \frac{a2}{b2}}{b1}} \]
      3. associate-*r/83.6%

        \[\leadsto \color{blue}{a1 \cdot \frac{\frac{a2}{b2}}{b1}} \]
    3. Simplified83.6%

      \[\leadsto \color{blue}{a1 \cdot \frac{\frac{a2}{b2}}{b1}} \]
    4. Step-by-step derivation
      1. associate-*r/95.3%

        \[\leadsto \color{blue}{\frac{a1 \cdot \frac{a2}{b2}}{b1}} \]
      2. associate-*l/84.2%

        \[\leadsto \color{blue}{\frac{a1}{b1} \cdot \frac{a2}{b2}} \]
      3. clear-num84.2%

        \[\leadsto \frac{a1}{b1} \cdot \color{blue}{\frac{1}{\frac{b2}{a2}}} \]
      4. un-div-inv84.3%

        \[\leadsto \color{blue}{\frac{\frac{a1}{b1}}{\frac{b2}{a2}}} \]
    5. Applied egg-rr84.3%

      \[\leadsto \color{blue}{\frac{\frac{a1}{b1}}{\frac{b2}{a2}}} \]

    if -1.0000000000000001e272 < (*.f64 b1 b2) < -4.99999999999999955e-308 or 4.99999999999999992e-171 < (*.f64 b1 b2)

    1. Initial program 89.9%

      \[\frac{a1 \cdot a2}{b1 \cdot b2} \]
    2. Step-by-step derivation
      1. *-commutative89.9%

        \[\leadsto \frac{\color{blue}{a2 \cdot a1}}{b1 \cdot b2} \]
      2. associate-*l/96.4%

        \[\leadsto \color{blue}{\frac{a2}{b1 \cdot b2} \cdot a1} \]
      3. *-commutative96.4%

        \[\leadsto \frac{a2}{\color{blue}{b2 \cdot b1}} \cdot a1 \]
    3. Applied egg-rr96.4%

      \[\leadsto \color{blue}{\frac{a2}{b2 \cdot b1} \cdot a1} \]

    if -4.99999999999999955e-308 < (*.f64 b1 b2) < 4.99999999999999992e-171

    1. Initial program 76.2%

      \[\frac{a1 \cdot a2}{b1 \cdot b2} \]
    2. Step-by-step derivation
      1. *-commutative76.2%

        \[\leadsto \frac{\color{blue}{a2 \cdot a1}}{b1 \cdot b2} \]
      2. times-frac92.1%

        \[\leadsto \color{blue}{\frac{a2}{b1} \cdot \frac{a1}{b2}} \]
    3. Applied egg-rr92.1%

      \[\leadsto \color{blue}{\frac{a2}{b1} \cdot \frac{a1}{b2}} \]
  3. Recombined 3 regimes into one program.
  4. Final simplification94.6%

    \[\leadsto \begin{array}{l} \mathbf{if}\;b1 \cdot b2 \leq -1 \cdot 10^{+272}:\\ \;\;\;\;\frac{\frac{a1}{b1}}{\frac{b2}{a2}}\\ \mathbf{elif}\;b1 \cdot b2 \leq -5 \cdot 10^{-308} \lor \neg \left(b1 \cdot b2 \leq 5 \cdot 10^{-171}\right):\\ \;\;\;\;a1 \cdot \frac{a2}{b1 \cdot b2}\\ \mathbf{else}:\\ \;\;\;\;\frac{a2}{b1} \cdot \frac{a1}{b2}\\ \end{array} \]

Alternative 4: 86.6% accurate, 0.5× speedup?

\[\begin{array}{l} [a1, a2] = \mathsf{sort}([a1, a2])\\ [b1, b2] = \mathsf{sort}([b1, b2])\\ \\ \begin{array}{l} \mathbf{if}\;b1 \leq -2.7 \cdot 10^{+256}:\\ \;\;\;\;a2 \cdot \frac{a1}{b1 \cdot b2}\\ \mathbf{elif}\;b1 \leq -1.45 \cdot 10^{+63} \lor \neg \left(b1 \leq 1.6 \cdot 10^{-253}\right):\\ \;\;\;\;a1 \cdot \frac{\frac{a2}{b2}}{b1}\\ \mathbf{else}:\\ \;\;\;\;\frac{a2}{b1} \cdot \frac{a1}{b2}\\ \end{array} \end{array} \]
NOTE: a1 and a2 should be sorted in increasing order before calling this function.
NOTE: b1 and b2 should be sorted in increasing order before calling this function.
(FPCore (a1 a2 b1 b2)
 :precision binary64
 (if (<= b1 -2.7e+256)
   (* a2 (/ a1 (* b1 b2)))
   (if (or (<= b1 -1.45e+63) (not (<= b1 1.6e-253)))
     (* a1 (/ (/ a2 b2) b1))
     (* (/ a2 b1) (/ a1 b2)))))
assert(a1 < a2);
assert(b1 < b2);
double code(double a1, double a2, double b1, double b2) {
	double tmp;
	if (b1 <= -2.7e+256) {
		tmp = a2 * (a1 / (b1 * b2));
	} else if ((b1 <= -1.45e+63) || !(b1 <= 1.6e-253)) {
		tmp = a1 * ((a2 / b2) / b1);
	} else {
		tmp = (a2 / b1) * (a1 / b2);
	}
	return tmp;
}
NOTE: a1 and a2 should be sorted in increasing order before calling this function.
NOTE: b1 and b2 should be sorted in increasing order before calling this function.
real(8) function code(a1, a2, b1, b2)
    real(8), intent (in) :: a1
    real(8), intent (in) :: a2
    real(8), intent (in) :: b1
    real(8), intent (in) :: b2
    real(8) :: tmp
    if (b1 <= (-2.7d+256)) then
        tmp = a2 * (a1 / (b1 * b2))
    else if ((b1 <= (-1.45d+63)) .or. (.not. (b1 <= 1.6d-253))) then
        tmp = a1 * ((a2 / b2) / b1)
    else
        tmp = (a2 / b1) * (a1 / b2)
    end if
    code = tmp
end function
assert a1 < a2;
assert b1 < b2;
public static double code(double a1, double a2, double b1, double b2) {
	double tmp;
	if (b1 <= -2.7e+256) {
		tmp = a2 * (a1 / (b1 * b2));
	} else if ((b1 <= -1.45e+63) || !(b1 <= 1.6e-253)) {
		tmp = a1 * ((a2 / b2) / b1);
	} else {
		tmp = (a2 / b1) * (a1 / b2);
	}
	return tmp;
}
[a1, a2] = sort([a1, a2])
[b1, b2] = sort([b1, b2])
def code(a1, a2, b1, b2):
	tmp = 0
	if b1 <= -2.7e+256:
		tmp = a2 * (a1 / (b1 * b2))
	elif (b1 <= -1.45e+63) or not (b1 <= 1.6e-253):
		tmp = a1 * ((a2 / b2) / b1)
	else:
		tmp = (a2 / b1) * (a1 / b2)
	return tmp
a1, a2 = sort([a1, a2])
b1, b2 = sort([b1, b2])
function code(a1, a2, b1, b2)
	tmp = 0.0
	if (b1 <= -2.7e+256)
		tmp = Float64(a2 * Float64(a1 / Float64(b1 * b2)));
	elseif ((b1 <= -1.45e+63) || !(b1 <= 1.6e-253))
		tmp = Float64(a1 * Float64(Float64(a2 / b2) / b1));
	else
		tmp = Float64(Float64(a2 / b1) * Float64(a1 / b2));
	end
	return tmp
end
a1, a2 = num2cell(sort([a1, a2])){:}
b1, b2 = num2cell(sort([b1, b2])){:}
function tmp_2 = code(a1, a2, b1, b2)
	tmp = 0.0;
	if (b1 <= -2.7e+256)
		tmp = a2 * (a1 / (b1 * b2));
	elseif ((b1 <= -1.45e+63) || ~((b1 <= 1.6e-253)))
		tmp = a1 * ((a2 / b2) / b1);
	else
		tmp = (a2 / b1) * (a1 / b2);
	end
	tmp_2 = tmp;
end
NOTE: a1 and a2 should be sorted in increasing order before calling this function.
NOTE: b1 and b2 should be sorted in increasing order before calling this function.
code[a1_, a2_, b1_, b2_] := If[LessEqual[b1, -2.7e+256], N[(a2 * N[(a1 / N[(b1 * b2), $MachinePrecision]), $MachinePrecision]), $MachinePrecision], If[Or[LessEqual[b1, -1.45e+63], N[Not[LessEqual[b1, 1.6e-253]], $MachinePrecision]], N[(a1 * N[(N[(a2 / b2), $MachinePrecision] / b1), $MachinePrecision]), $MachinePrecision], N[(N[(a2 / b1), $MachinePrecision] * N[(a1 / b2), $MachinePrecision]), $MachinePrecision]]]
\begin{array}{l}
[a1, a2] = \mathsf{sort}([a1, a2])\\
[b1, b2] = \mathsf{sort}([b1, b2])\\
\\
\begin{array}{l}
\mathbf{if}\;b1 \leq -2.7 \cdot 10^{+256}:\\
\;\;\;\;a2 \cdot \frac{a1}{b1 \cdot b2}\\

\mathbf{elif}\;b1 \leq -1.45 \cdot 10^{+63} \lor \neg \left(b1 \leq 1.6 \cdot 10^{-253}\right):\\
\;\;\;\;a1 \cdot \frac{\frac{a2}{b2}}{b1}\\

\mathbf{else}:\\
\;\;\;\;\frac{a2}{b1} \cdot \frac{a1}{b2}\\


\end{array}
\end{array}
Derivation
  1. Split input into 3 regimes
  2. if b1 < -2.69999999999999995e256

    1. Initial program 83.9%

      \[\frac{a1 \cdot a2}{b1 \cdot b2} \]
    2. Step-by-step derivation
      1. associate-/l*99.2%

        \[\leadsto \color{blue}{\frac{a1}{\frac{b1 \cdot b2}{a2}}} \]
      2. associate-/r/84.3%

        \[\leadsto \color{blue}{\frac{a1}{b1 \cdot b2} \cdot a2} \]
      3. *-commutative84.3%

        \[\leadsto \frac{a1}{\color{blue}{b2 \cdot b1}} \cdot a2 \]
    3. Applied egg-rr84.3%

      \[\leadsto \color{blue}{\frac{a1}{b2 \cdot b1} \cdot a2} \]

    if -2.69999999999999995e256 < b1 < -1.45e63 or 1.5999999999999999e-253 < b1

    1. Initial program 85.5%

      \[\frac{a1 \cdot a2}{b1 \cdot b2} \]
    2. Step-by-step derivation
      1. times-frac85.1%

        \[\leadsto \color{blue}{\frac{a1}{b1} \cdot \frac{a2}{b2}} \]
      2. associate-*l/88.2%

        \[\leadsto \color{blue}{\frac{a1 \cdot \frac{a2}{b2}}{b1}} \]
      3. associate-*r/89.2%

        \[\leadsto \color{blue}{a1 \cdot \frac{\frac{a2}{b2}}{b1}} \]
    3. Simplified89.2%

      \[\leadsto \color{blue}{a1 \cdot \frac{\frac{a2}{b2}}{b1}} \]

    if -1.45e63 < b1 < 1.5999999999999999e-253

    1. Initial program 82.0%

      \[\frac{a1 \cdot a2}{b1 \cdot b2} \]
    2. Step-by-step derivation
      1. *-commutative82.0%

        \[\leadsto \frac{\color{blue}{a2 \cdot a1}}{b1 \cdot b2} \]
      2. times-frac91.6%

        \[\leadsto \color{blue}{\frac{a2}{b1} \cdot \frac{a1}{b2}} \]
    3. Applied egg-rr91.6%

      \[\leadsto \color{blue}{\frac{a2}{b1} \cdot \frac{a1}{b2}} \]
  3. Recombined 3 regimes into one program.
  4. Final simplification89.8%

    \[\leadsto \begin{array}{l} \mathbf{if}\;b1 \leq -2.7 \cdot 10^{+256}:\\ \;\;\;\;a2 \cdot \frac{a1}{b1 \cdot b2}\\ \mathbf{elif}\;b1 \leq -1.45 \cdot 10^{+63} \lor \neg \left(b1 \leq 1.6 \cdot 10^{-253}\right):\\ \;\;\;\;a1 \cdot \frac{\frac{a2}{b2}}{b1}\\ \mathbf{else}:\\ \;\;\;\;\frac{a2}{b1} \cdot \frac{a1}{b2}\\ \end{array} \]

Alternative 5: 86.3% accurate, 0.5× speedup?

\[\begin{array}{l} [a1, a2] = \mathsf{sort}([a1, a2])\\ [b1, b2] = \mathsf{sort}([b1, b2])\\ \\ \begin{array}{l} \mathbf{if}\;b1 \leq -4 \cdot 10^{+256}:\\ \;\;\;\;a2 \cdot \frac{a1}{b1 \cdot b2}\\ \mathbf{elif}\;b1 \leq -5 \cdot 10^{+60}:\\ \;\;\;\;a1 \cdot \frac{\frac{a2}{b2}}{b1}\\ \mathbf{elif}\;b1 \leq -1.52 \cdot 10^{-290}:\\ \;\;\;\;\frac{a2}{b1} \cdot \frac{a1}{b2}\\ \mathbf{else}:\\ \;\;\;\;a1 \cdot \frac{a2}{b1 \cdot b2}\\ \end{array} \end{array} \]
NOTE: a1 and a2 should be sorted in increasing order before calling this function.
NOTE: b1 and b2 should be sorted in increasing order before calling this function.
(FPCore (a1 a2 b1 b2)
 :precision binary64
 (if (<= b1 -4e+256)
   (* a2 (/ a1 (* b1 b2)))
   (if (<= b1 -5e+60)
     (* a1 (/ (/ a2 b2) b1))
     (if (<= b1 -1.52e-290) (* (/ a2 b1) (/ a1 b2)) (* a1 (/ a2 (* b1 b2)))))))
assert(a1 < a2);
assert(b1 < b2);
double code(double a1, double a2, double b1, double b2) {
	double tmp;
	if (b1 <= -4e+256) {
		tmp = a2 * (a1 / (b1 * b2));
	} else if (b1 <= -5e+60) {
		tmp = a1 * ((a2 / b2) / b1);
	} else if (b1 <= -1.52e-290) {
		tmp = (a2 / b1) * (a1 / b2);
	} else {
		tmp = a1 * (a2 / (b1 * b2));
	}
	return tmp;
}
NOTE: a1 and a2 should be sorted in increasing order before calling this function.
NOTE: b1 and b2 should be sorted in increasing order before calling this function.
real(8) function code(a1, a2, b1, b2)
    real(8), intent (in) :: a1
    real(8), intent (in) :: a2
    real(8), intent (in) :: b1
    real(8), intent (in) :: b2
    real(8) :: tmp
    if (b1 <= (-4d+256)) then
        tmp = a2 * (a1 / (b1 * b2))
    else if (b1 <= (-5d+60)) then
        tmp = a1 * ((a2 / b2) / b1)
    else if (b1 <= (-1.52d-290)) then
        tmp = (a2 / b1) * (a1 / b2)
    else
        tmp = a1 * (a2 / (b1 * b2))
    end if
    code = tmp
end function
assert a1 < a2;
assert b1 < b2;
public static double code(double a1, double a2, double b1, double b2) {
	double tmp;
	if (b1 <= -4e+256) {
		tmp = a2 * (a1 / (b1 * b2));
	} else if (b1 <= -5e+60) {
		tmp = a1 * ((a2 / b2) / b1);
	} else if (b1 <= -1.52e-290) {
		tmp = (a2 / b1) * (a1 / b2);
	} else {
		tmp = a1 * (a2 / (b1 * b2));
	}
	return tmp;
}
[a1, a2] = sort([a1, a2])
[b1, b2] = sort([b1, b2])
def code(a1, a2, b1, b2):
	tmp = 0
	if b1 <= -4e+256:
		tmp = a2 * (a1 / (b1 * b2))
	elif b1 <= -5e+60:
		tmp = a1 * ((a2 / b2) / b1)
	elif b1 <= -1.52e-290:
		tmp = (a2 / b1) * (a1 / b2)
	else:
		tmp = a1 * (a2 / (b1 * b2))
	return tmp
a1, a2 = sort([a1, a2])
b1, b2 = sort([b1, b2])
function code(a1, a2, b1, b2)
	tmp = 0.0
	if (b1 <= -4e+256)
		tmp = Float64(a2 * Float64(a1 / Float64(b1 * b2)));
	elseif (b1 <= -5e+60)
		tmp = Float64(a1 * Float64(Float64(a2 / b2) / b1));
	elseif (b1 <= -1.52e-290)
		tmp = Float64(Float64(a2 / b1) * Float64(a1 / b2));
	else
		tmp = Float64(a1 * Float64(a2 / Float64(b1 * b2)));
	end
	return tmp
end
a1, a2 = num2cell(sort([a1, a2])){:}
b1, b2 = num2cell(sort([b1, b2])){:}
function tmp_2 = code(a1, a2, b1, b2)
	tmp = 0.0;
	if (b1 <= -4e+256)
		tmp = a2 * (a1 / (b1 * b2));
	elseif (b1 <= -5e+60)
		tmp = a1 * ((a2 / b2) / b1);
	elseif (b1 <= -1.52e-290)
		tmp = (a2 / b1) * (a1 / b2);
	else
		tmp = a1 * (a2 / (b1 * b2));
	end
	tmp_2 = tmp;
end
NOTE: a1 and a2 should be sorted in increasing order before calling this function.
NOTE: b1 and b2 should be sorted in increasing order before calling this function.
code[a1_, a2_, b1_, b2_] := If[LessEqual[b1, -4e+256], N[(a2 * N[(a1 / N[(b1 * b2), $MachinePrecision]), $MachinePrecision]), $MachinePrecision], If[LessEqual[b1, -5e+60], N[(a1 * N[(N[(a2 / b2), $MachinePrecision] / b1), $MachinePrecision]), $MachinePrecision], If[LessEqual[b1, -1.52e-290], N[(N[(a2 / b1), $MachinePrecision] * N[(a1 / b2), $MachinePrecision]), $MachinePrecision], N[(a1 * N[(a2 / N[(b1 * b2), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]]]]
\begin{array}{l}
[a1, a2] = \mathsf{sort}([a1, a2])\\
[b1, b2] = \mathsf{sort}([b1, b2])\\
\\
\begin{array}{l}
\mathbf{if}\;b1 \leq -4 \cdot 10^{+256}:\\
\;\;\;\;a2 \cdot \frac{a1}{b1 \cdot b2}\\

\mathbf{elif}\;b1 \leq -5 \cdot 10^{+60}:\\
\;\;\;\;a1 \cdot \frac{\frac{a2}{b2}}{b1}\\

\mathbf{elif}\;b1 \leq -1.52 \cdot 10^{-290}:\\
\;\;\;\;\frac{a2}{b1} \cdot \frac{a1}{b2}\\

\mathbf{else}:\\
\;\;\;\;a1 \cdot \frac{a2}{b1 \cdot b2}\\


\end{array}
\end{array}
Derivation
  1. Split input into 4 regimes
  2. if b1 < -4.0000000000000001e256

    1. Initial program 83.9%

      \[\frac{a1 \cdot a2}{b1 \cdot b2} \]
    2. Step-by-step derivation
      1. associate-/l*99.2%

        \[\leadsto \color{blue}{\frac{a1}{\frac{b1 \cdot b2}{a2}}} \]
      2. associate-/r/84.3%

        \[\leadsto \color{blue}{\frac{a1}{b1 \cdot b2} \cdot a2} \]
      3. *-commutative84.3%

        \[\leadsto \frac{a1}{\color{blue}{b2 \cdot b1}} \cdot a2 \]
    3. Applied egg-rr84.3%

      \[\leadsto \color{blue}{\frac{a1}{b2 \cdot b1} \cdot a2} \]

    if -4.0000000000000001e256 < b1 < -4.99999999999999975e60

    1. Initial program 80.1%

      \[\frac{a1 \cdot a2}{b1 \cdot b2} \]
    2. Step-by-step derivation
      1. times-frac78.6%

        \[\leadsto \color{blue}{\frac{a1}{b1} \cdot \frac{a2}{b2}} \]
      2. associate-*l/83.8%

        \[\leadsto \color{blue}{\frac{a1 \cdot \frac{a2}{b2}}{b1}} \]
      3. associate-*r/82.5%

        \[\leadsto \color{blue}{a1 \cdot \frac{\frac{a2}{b2}}{b1}} \]
    3. Simplified82.5%

      \[\leadsto \color{blue}{a1 \cdot \frac{\frac{a2}{b2}}{b1}} \]

    if -4.99999999999999975e60 < b1 < -1.5199999999999999e-290

    1. Initial program 82.7%

      \[\frac{a1 \cdot a2}{b1 \cdot b2} \]
    2. Step-by-step derivation
      1. *-commutative82.7%

        \[\leadsto \frac{\color{blue}{a2 \cdot a1}}{b1 \cdot b2} \]
      2. times-frac91.9%

        \[\leadsto \color{blue}{\frac{a2}{b1} \cdot \frac{a1}{b2}} \]
    3. Applied egg-rr91.9%

      \[\leadsto \color{blue}{\frac{a2}{b1} \cdot \frac{a1}{b2}} \]

    if -1.5199999999999999e-290 < b1

    1. Initial program 86.6%

      \[\frac{a1 \cdot a2}{b1 \cdot b2} \]
    2. Step-by-step derivation
      1. *-commutative86.6%

        \[\leadsto \frac{\color{blue}{a2 \cdot a1}}{b1 \cdot b2} \]
      2. associate-*l/91.6%

        \[\leadsto \color{blue}{\frac{a2}{b1 \cdot b2} \cdot a1} \]
      3. *-commutative91.6%

        \[\leadsto \frac{a2}{\color{blue}{b2 \cdot b1}} \cdot a1 \]
    3. Applied egg-rr91.6%

      \[\leadsto \color{blue}{\frac{a2}{b2 \cdot b1} \cdot a1} \]
  3. Recombined 4 regimes into one program.
  4. Final simplification89.8%

    \[\leadsto \begin{array}{l} \mathbf{if}\;b1 \leq -4 \cdot 10^{+256}:\\ \;\;\;\;a2 \cdot \frac{a1}{b1 \cdot b2}\\ \mathbf{elif}\;b1 \leq -5 \cdot 10^{+60}:\\ \;\;\;\;a1 \cdot \frac{\frac{a2}{b2}}{b1}\\ \mathbf{elif}\;b1 \leq -1.52 \cdot 10^{-290}:\\ \;\;\;\;\frac{a2}{b1} \cdot \frac{a1}{b2}\\ \mathbf{else}:\\ \;\;\;\;a1 \cdot \frac{a2}{b1 \cdot b2}\\ \end{array} \]

Alternative 6: 85.9% accurate, 0.5× speedup?

\[\begin{array}{l} [a1, a2] = \mathsf{sort}([a1, a2])\\ [b1, b2] = \mathsf{sort}([b1, b2])\\ \\ \begin{array}{l} \mathbf{if}\;b1 \leq -9.4 \cdot 10^{+257}:\\ \;\;\;\;a2 \cdot \frac{a1}{b1 \cdot b2}\\ \mathbf{elif}\;b1 \leq -1.28 \cdot 10^{+51}:\\ \;\;\;\;a1 \cdot \frac{\frac{a2}{b2}}{b1}\\ \mathbf{elif}\;b1 \leq -1.15 \cdot 10^{-159}:\\ \;\;\;\;\frac{a2}{b1 \cdot \frac{b2}{a1}}\\ \mathbf{else}:\\ \;\;\;\;a1 \cdot \frac{a2}{b1 \cdot b2}\\ \end{array} \end{array} \]
NOTE: a1 and a2 should be sorted in increasing order before calling this function.
NOTE: b1 and b2 should be sorted in increasing order before calling this function.
(FPCore (a1 a2 b1 b2)
 :precision binary64
 (if (<= b1 -9.4e+257)
   (* a2 (/ a1 (* b1 b2)))
   (if (<= b1 -1.28e+51)
     (* a1 (/ (/ a2 b2) b1))
     (if (<= b1 -1.15e-159) (/ a2 (* b1 (/ b2 a1))) (* a1 (/ a2 (* b1 b2)))))))
assert(a1 < a2);
assert(b1 < b2);
double code(double a1, double a2, double b1, double b2) {
	double tmp;
	if (b1 <= -9.4e+257) {
		tmp = a2 * (a1 / (b1 * b2));
	} else if (b1 <= -1.28e+51) {
		tmp = a1 * ((a2 / b2) / b1);
	} else if (b1 <= -1.15e-159) {
		tmp = a2 / (b1 * (b2 / a1));
	} else {
		tmp = a1 * (a2 / (b1 * b2));
	}
	return tmp;
}
NOTE: a1 and a2 should be sorted in increasing order before calling this function.
NOTE: b1 and b2 should be sorted in increasing order before calling this function.
real(8) function code(a1, a2, b1, b2)
    real(8), intent (in) :: a1
    real(8), intent (in) :: a2
    real(8), intent (in) :: b1
    real(8), intent (in) :: b2
    real(8) :: tmp
    if (b1 <= (-9.4d+257)) then
        tmp = a2 * (a1 / (b1 * b2))
    else if (b1 <= (-1.28d+51)) then
        tmp = a1 * ((a2 / b2) / b1)
    else if (b1 <= (-1.15d-159)) then
        tmp = a2 / (b1 * (b2 / a1))
    else
        tmp = a1 * (a2 / (b1 * b2))
    end if
    code = tmp
end function
assert a1 < a2;
assert b1 < b2;
public static double code(double a1, double a2, double b1, double b2) {
	double tmp;
	if (b1 <= -9.4e+257) {
		tmp = a2 * (a1 / (b1 * b2));
	} else if (b1 <= -1.28e+51) {
		tmp = a1 * ((a2 / b2) / b1);
	} else if (b1 <= -1.15e-159) {
		tmp = a2 / (b1 * (b2 / a1));
	} else {
		tmp = a1 * (a2 / (b1 * b2));
	}
	return tmp;
}
[a1, a2] = sort([a1, a2])
[b1, b2] = sort([b1, b2])
def code(a1, a2, b1, b2):
	tmp = 0
	if b1 <= -9.4e+257:
		tmp = a2 * (a1 / (b1 * b2))
	elif b1 <= -1.28e+51:
		tmp = a1 * ((a2 / b2) / b1)
	elif b1 <= -1.15e-159:
		tmp = a2 / (b1 * (b2 / a1))
	else:
		tmp = a1 * (a2 / (b1 * b2))
	return tmp
a1, a2 = sort([a1, a2])
b1, b2 = sort([b1, b2])
function code(a1, a2, b1, b2)
	tmp = 0.0
	if (b1 <= -9.4e+257)
		tmp = Float64(a2 * Float64(a1 / Float64(b1 * b2)));
	elseif (b1 <= -1.28e+51)
		tmp = Float64(a1 * Float64(Float64(a2 / b2) / b1));
	elseif (b1 <= -1.15e-159)
		tmp = Float64(a2 / Float64(b1 * Float64(b2 / a1)));
	else
		tmp = Float64(a1 * Float64(a2 / Float64(b1 * b2)));
	end
	return tmp
end
a1, a2 = num2cell(sort([a1, a2])){:}
b1, b2 = num2cell(sort([b1, b2])){:}
function tmp_2 = code(a1, a2, b1, b2)
	tmp = 0.0;
	if (b1 <= -9.4e+257)
		tmp = a2 * (a1 / (b1 * b2));
	elseif (b1 <= -1.28e+51)
		tmp = a1 * ((a2 / b2) / b1);
	elseif (b1 <= -1.15e-159)
		tmp = a2 / (b1 * (b2 / a1));
	else
		tmp = a1 * (a2 / (b1 * b2));
	end
	tmp_2 = tmp;
end
NOTE: a1 and a2 should be sorted in increasing order before calling this function.
NOTE: b1 and b2 should be sorted in increasing order before calling this function.
code[a1_, a2_, b1_, b2_] := If[LessEqual[b1, -9.4e+257], N[(a2 * N[(a1 / N[(b1 * b2), $MachinePrecision]), $MachinePrecision]), $MachinePrecision], If[LessEqual[b1, -1.28e+51], N[(a1 * N[(N[(a2 / b2), $MachinePrecision] / b1), $MachinePrecision]), $MachinePrecision], If[LessEqual[b1, -1.15e-159], N[(a2 / N[(b1 * N[(b2 / a1), $MachinePrecision]), $MachinePrecision]), $MachinePrecision], N[(a1 * N[(a2 / N[(b1 * b2), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]]]]
\begin{array}{l}
[a1, a2] = \mathsf{sort}([a1, a2])\\
[b1, b2] = \mathsf{sort}([b1, b2])\\
\\
\begin{array}{l}
\mathbf{if}\;b1 \leq -9.4 \cdot 10^{+257}:\\
\;\;\;\;a2 \cdot \frac{a1}{b1 \cdot b2}\\

\mathbf{elif}\;b1 \leq -1.28 \cdot 10^{+51}:\\
\;\;\;\;a1 \cdot \frac{\frac{a2}{b2}}{b1}\\

\mathbf{elif}\;b1 \leq -1.15 \cdot 10^{-159}:\\
\;\;\;\;\frac{a2}{b1 \cdot \frac{b2}{a1}}\\

\mathbf{else}:\\
\;\;\;\;a1 \cdot \frac{a2}{b1 \cdot b2}\\


\end{array}
\end{array}
Derivation
  1. Split input into 4 regimes
  2. if b1 < -9.4e257

    1. Initial program 83.9%

      \[\frac{a1 \cdot a2}{b1 \cdot b2} \]
    2. Step-by-step derivation
      1. associate-/l*99.2%

        \[\leadsto \color{blue}{\frac{a1}{\frac{b1 \cdot b2}{a2}}} \]
      2. associate-/r/84.3%

        \[\leadsto \color{blue}{\frac{a1}{b1 \cdot b2} \cdot a2} \]
      3. *-commutative84.3%

        \[\leadsto \frac{a1}{\color{blue}{b2 \cdot b1}} \cdot a2 \]
    3. Applied egg-rr84.3%

      \[\leadsto \color{blue}{\frac{a1}{b2 \cdot b1} \cdot a2} \]

    if -9.4e257 < b1 < -1.27999999999999993e51

    1. Initial program 80.4%

      \[\frac{a1 \cdot a2}{b1 \cdot b2} \]
    2. Step-by-step derivation
      1. times-frac79.1%

        \[\leadsto \color{blue}{\frac{a1}{b1} \cdot \frac{a2}{b2}} \]
      2. associate-*l/84.1%

        \[\leadsto \color{blue}{\frac{a1 \cdot \frac{a2}{b2}}{b1}} \]
      3. associate-*r/82.8%

        \[\leadsto \color{blue}{a1 \cdot \frac{\frac{a2}{b2}}{b1}} \]
    3. Simplified82.8%

      \[\leadsto \color{blue}{a1 \cdot \frac{\frac{a2}{b2}}{b1}} \]

    if -1.27999999999999993e51 < b1 < -1.14999999999999989e-159

    1. Initial program 78.7%

      \[\frac{a1 \cdot a2}{b1 \cdot b2} \]
    2. Step-by-step derivation
      1. *-commutative78.7%

        \[\leadsto \frac{\color{blue}{a2 \cdot a1}}{b1 \cdot b2} \]
      2. associate-*l/93.1%

        \[\leadsto \color{blue}{\frac{a2}{b1 \cdot b2} \cdot a1} \]
      3. *-commutative93.1%

        \[\leadsto \frac{a2}{\color{blue}{b2 \cdot b1}} \cdot a1 \]
    3. Applied egg-rr93.1%

      \[\leadsto \color{blue}{\frac{a2}{b2 \cdot b1} \cdot a1} \]
    4. Step-by-step derivation
      1. associate-*l/78.7%

        \[\leadsto \color{blue}{\frac{a2 \cdot a1}{b2 \cdot b1}} \]
      2. *-commutative78.7%

        \[\leadsto \frac{a2 \cdot a1}{\color{blue}{b1 \cdot b2}} \]
      3. frac-times97.0%

        \[\leadsto \color{blue}{\frac{a2}{b1} \cdot \frac{a1}{b2}} \]
      4. clear-num97.1%

        \[\leadsto \frac{a2}{b1} \cdot \color{blue}{\frac{1}{\frac{b2}{a1}}} \]
      5. frac-times96.1%

        \[\leadsto \color{blue}{\frac{a2 \cdot 1}{b1 \cdot \frac{b2}{a1}}} \]
      6. *-commutative96.1%

        \[\leadsto \frac{\color{blue}{1 \cdot a2}}{b1 \cdot \frac{b2}{a1}} \]
      7. *-un-lft-identity96.1%

        \[\leadsto \frac{\color{blue}{a2}}{b1 \cdot \frac{b2}{a1}} \]
    5. Applied egg-rr96.1%

      \[\leadsto \color{blue}{\frac{a2}{b1 \cdot \frac{b2}{a1}}} \]

    if -1.14999999999999989e-159 < b1

    1. Initial program 86.8%

      \[\frac{a1 \cdot a2}{b1 \cdot b2} \]
    2. Step-by-step derivation
      1. *-commutative86.8%

        \[\leadsto \frac{\color{blue}{a2 \cdot a1}}{b1 \cdot b2} \]
      2. associate-*l/91.6%

        \[\leadsto \color{blue}{\frac{a2}{b1 \cdot b2} \cdot a1} \]
      3. *-commutative91.6%

        \[\leadsto \frac{a2}{\color{blue}{b2 \cdot b1}} \cdot a1 \]
    3. Applied egg-rr91.6%

      \[\leadsto \color{blue}{\frac{a2}{b2 \cdot b1} \cdot a1} \]
  3. Recombined 4 regimes into one program.
  4. Final simplification90.4%

    \[\leadsto \begin{array}{l} \mathbf{if}\;b1 \leq -9.4 \cdot 10^{+257}:\\ \;\;\;\;a2 \cdot \frac{a1}{b1 \cdot b2}\\ \mathbf{elif}\;b1 \leq -1.28 \cdot 10^{+51}:\\ \;\;\;\;a1 \cdot \frac{\frac{a2}{b2}}{b1}\\ \mathbf{elif}\;b1 \leq -1.15 \cdot 10^{-159}:\\ \;\;\;\;\frac{a2}{b1 \cdot \frac{b2}{a1}}\\ \mathbf{else}:\\ \;\;\;\;a1 \cdot \frac{a2}{b1 \cdot b2}\\ \end{array} \]

Alternative 7: 86.8% accurate, 0.8× speedup?

\[\begin{array}{l} [a1, a2] = \mathsf{sort}([a1, a2])\\ [b1, b2] = \mathsf{sort}([b1, b2])\\ \\ \begin{array}{l} \mathbf{if}\;b2 \leq 2.2 \cdot 10^{-157}:\\ \;\;\;\;a2 \cdot \frac{\frac{a1}{b1}}{b2}\\ \mathbf{else}:\\ \;\;\;\;a1 \cdot \frac{\frac{a2}{b2}}{b1}\\ \end{array} \end{array} \]
NOTE: a1 and a2 should be sorted in increasing order before calling this function.
NOTE: b1 and b2 should be sorted in increasing order before calling this function.
(FPCore (a1 a2 b1 b2)
 :precision binary64
 (if (<= b2 2.2e-157) (* a2 (/ (/ a1 b1) b2)) (* a1 (/ (/ a2 b2) b1))))
assert(a1 < a2);
assert(b1 < b2);
double code(double a1, double a2, double b1, double b2) {
	double tmp;
	if (b2 <= 2.2e-157) {
		tmp = a2 * ((a1 / b1) / b2);
	} else {
		tmp = a1 * ((a2 / b2) / b1);
	}
	return tmp;
}
NOTE: a1 and a2 should be sorted in increasing order before calling this function.
NOTE: b1 and b2 should be sorted in increasing order before calling this function.
real(8) function code(a1, a2, b1, b2)
    real(8), intent (in) :: a1
    real(8), intent (in) :: a2
    real(8), intent (in) :: b1
    real(8), intent (in) :: b2
    real(8) :: tmp
    if (b2 <= 2.2d-157) then
        tmp = a2 * ((a1 / b1) / b2)
    else
        tmp = a1 * ((a2 / b2) / b1)
    end if
    code = tmp
end function
assert a1 < a2;
assert b1 < b2;
public static double code(double a1, double a2, double b1, double b2) {
	double tmp;
	if (b2 <= 2.2e-157) {
		tmp = a2 * ((a1 / b1) / b2);
	} else {
		tmp = a1 * ((a2 / b2) / b1);
	}
	return tmp;
}
[a1, a2] = sort([a1, a2])
[b1, b2] = sort([b1, b2])
def code(a1, a2, b1, b2):
	tmp = 0
	if b2 <= 2.2e-157:
		tmp = a2 * ((a1 / b1) / b2)
	else:
		tmp = a1 * ((a2 / b2) / b1)
	return tmp
a1, a2 = sort([a1, a2])
b1, b2 = sort([b1, b2])
function code(a1, a2, b1, b2)
	tmp = 0.0
	if (b2 <= 2.2e-157)
		tmp = Float64(a2 * Float64(Float64(a1 / b1) / b2));
	else
		tmp = Float64(a1 * Float64(Float64(a2 / b2) / b1));
	end
	return tmp
end
a1, a2 = num2cell(sort([a1, a2])){:}
b1, b2 = num2cell(sort([b1, b2])){:}
function tmp_2 = code(a1, a2, b1, b2)
	tmp = 0.0;
	if (b2 <= 2.2e-157)
		tmp = a2 * ((a1 / b1) / b2);
	else
		tmp = a1 * ((a2 / b2) / b1);
	end
	tmp_2 = tmp;
end
NOTE: a1 and a2 should be sorted in increasing order before calling this function.
NOTE: b1 and b2 should be sorted in increasing order before calling this function.
code[a1_, a2_, b1_, b2_] := If[LessEqual[b2, 2.2e-157], N[(a2 * N[(N[(a1 / b1), $MachinePrecision] / b2), $MachinePrecision]), $MachinePrecision], N[(a1 * N[(N[(a2 / b2), $MachinePrecision] / b1), $MachinePrecision]), $MachinePrecision]]
\begin{array}{l}
[a1, a2] = \mathsf{sort}([a1, a2])\\
[b1, b2] = \mathsf{sort}([b1, b2])\\
\\
\begin{array}{l}
\mathbf{if}\;b2 \leq 2.2 \cdot 10^{-157}:\\
\;\;\;\;a2 \cdot \frac{\frac{a1}{b1}}{b2}\\

\mathbf{else}:\\
\;\;\;\;a1 \cdot \frac{\frac{a2}{b2}}{b1}\\


\end{array}
\end{array}
Derivation
  1. Split input into 2 regimes
  2. if b2 < 2.2000000000000001e-157

    1. Initial program 84.3%

      \[\frac{a1 \cdot a2}{b1 \cdot b2} \]
    2. Step-by-step derivation
      1. times-frac84.9%

        \[\leadsto \color{blue}{\frac{a1}{b1} \cdot \frac{a2}{b2}} \]
      2. associate-*l/86.0%

        \[\leadsto \color{blue}{\frac{a1 \cdot \frac{a2}{b2}}{b1}} \]
      3. associate-*r/89.0%

        \[\leadsto \color{blue}{a1 \cdot \frac{\frac{a2}{b2}}{b1}} \]
    3. Simplified89.0%

      \[\leadsto \color{blue}{a1 \cdot \frac{\frac{a2}{b2}}{b1}} \]
    4. Taylor expanded in a1 around 0 84.3%

      \[\leadsto \color{blue}{\frac{a1 \cdot a2}{b1 \cdot b2}} \]
    5. Step-by-step derivation
      1. times-frac84.9%

        \[\leadsto \color{blue}{\frac{a1}{b1} \cdot \frac{a2}{b2}} \]
      2. *-commutative84.9%

        \[\leadsto \color{blue}{\frac{a2}{b2} \cdot \frac{a1}{b1}} \]
      3. associate-*l/81.6%

        \[\leadsto \color{blue}{\frac{a2 \cdot \frac{a1}{b1}}{b2}} \]
      4. associate-*r/85.4%

        \[\leadsto \color{blue}{a2 \cdot \frac{\frac{a1}{b1}}{b2}} \]
    6. Simplified85.4%

      \[\leadsto \color{blue}{a2 \cdot \frac{\frac{a1}{b1}}{b2}} \]

    if 2.2000000000000001e-157 < b2

    1. Initial program 84.6%

      \[\frac{a1 \cdot a2}{b1 \cdot b2} \]
    2. Step-by-step derivation
      1. times-frac88.1%

        \[\leadsto \color{blue}{\frac{a1}{b1} \cdot \frac{a2}{b2}} \]
      2. associate-*l/90.6%

        \[\leadsto \color{blue}{\frac{a1 \cdot \frac{a2}{b2}}{b1}} \]
      3. associate-*r/91.7%

        \[\leadsto \color{blue}{a1 \cdot \frac{\frac{a2}{b2}}{b1}} \]
    3. Simplified91.7%

      \[\leadsto \color{blue}{a1 \cdot \frac{\frac{a2}{b2}}{b1}} \]
  3. Recombined 2 regimes into one program.
  4. Final simplification87.9%

    \[\leadsto \begin{array}{l} \mathbf{if}\;b2 \leq 2.2 \cdot 10^{-157}:\\ \;\;\;\;a2 \cdot \frac{\frac{a1}{b1}}{b2}\\ \mathbf{else}:\\ \;\;\;\;a1 \cdot \frac{\frac{a2}{b2}}{b1}\\ \end{array} \]

Alternative 8: 86.1% accurate, 0.8× speedup?

\[\begin{array}{l} [a1, a2] = \mathsf{sort}([a1, a2])\\ [b1, b2] = \mathsf{sort}([b1, b2])\\ \\ \begin{array}{l} \mathbf{if}\;b1 \leq -4.8 \cdot 10^{+256}:\\ \;\;\;\;a2 \cdot \frac{a1}{b1 \cdot b2}\\ \mathbf{else}:\\ \;\;\;\;a1 \cdot \frac{\frac{a2}{b2}}{b1}\\ \end{array} \end{array} \]
NOTE: a1 and a2 should be sorted in increasing order before calling this function.
NOTE: b1 and b2 should be sorted in increasing order before calling this function.
(FPCore (a1 a2 b1 b2)
 :precision binary64
 (if (<= b1 -4.8e+256) (* a2 (/ a1 (* b1 b2))) (* a1 (/ (/ a2 b2) b1))))
assert(a1 < a2);
assert(b1 < b2);
double code(double a1, double a2, double b1, double b2) {
	double tmp;
	if (b1 <= -4.8e+256) {
		tmp = a2 * (a1 / (b1 * b2));
	} else {
		tmp = a1 * ((a2 / b2) / b1);
	}
	return tmp;
}
NOTE: a1 and a2 should be sorted in increasing order before calling this function.
NOTE: b1 and b2 should be sorted in increasing order before calling this function.
real(8) function code(a1, a2, b1, b2)
    real(8), intent (in) :: a1
    real(8), intent (in) :: a2
    real(8), intent (in) :: b1
    real(8), intent (in) :: b2
    real(8) :: tmp
    if (b1 <= (-4.8d+256)) then
        tmp = a2 * (a1 / (b1 * b2))
    else
        tmp = a1 * ((a2 / b2) / b1)
    end if
    code = tmp
end function
assert a1 < a2;
assert b1 < b2;
public static double code(double a1, double a2, double b1, double b2) {
	double tmp;
	if (b1 <= -4.8e+256) {
		tmp = a2 * (a1 / (b1 * b2));
	} else {
		tmp = a1 * ((a2 / b2) / b1);
	}
	return tmp;
}
[a1, a2] = sort([a1, a2])
[b1, b2] = sort([b1, b2])
def code(a1, a2, b1, b2):
	tmp = 0
	if b1 <= -4.8e+256:
		tmp = a2 * (a1 / (b1 * b2))
	else:
		tmp = a1 * ((a2 / b2) / b1)
	return tmp
a1, a2 = sort([a1, a2])
b1, b2 = sort([b1, b2])
function code(a1, a2, b1, b2)
	tmp = 0.0
	if (b1 <= -4.8e+256)
		tmp = Float64(a2 * Float64(a1 / Float64(b1 * b2)));
	else
		tmp = Float64(a1 * Float64(Float64(a2 / b2) / b1));
	end
	return tmp
end
a1, a2 = num2cell(sort([a1, a2])){:}
b1, b2 = num2cell(sort([b1, b2])){:}
function tmp_2 = code(a1, a2, b1, b2)
	tmp = 0.0;
	if (b1 <= -4.8e+256)
		tmp = a2 * (a1 / (b1 * b2));
	else
		tmp = a1 * ((a2 / b2) / b1);
	end
	tmp_2 = tmp;
end
NOTE: a1 and a2 should be sorted in increasing order before calling this function.
NOTE: b1 and b2 should be sorted in increasing order before calling this function.
code[a1_, a2_, b1_, b2_] := If[LessEqual[b1, -4.8e+256], N[(a2 * N[(a1 / N[(b1 * b2), $MachinePrecision]), $MachinePrecision]), $MachinePrecision], N[(a1 * N[(N[(a2 / b2), $MachinePrecision] / b1), $MachinePrecision]), $MachinePrecision]]
\begin{array}{l}
[a1, a2] = \mathsf{sort}([a1, a2])\\
[b1, b2] = \mathsf{sort}([b1, b2])\\
\\
\begin{array}{l}
\mathbf{if}\;b1 \leq -4.8 \cdot 10^{+256}:\\
\;\;\;\;a2 \cdot \frac{a1}{b1 \cdot b2}\\

\mathbf{else}:\\
\;\;\;\;a1 \cdot \frac{\frac{a2}{b2}}{b1}\\


\end{array}
\end{array}
Derivation
  1. Split input into 2 regimes
  2. if b1 < -4.80000000000000028e256

    1. Initial program 83.9%

      \[\frac{a1 \cdot a2}{b1 \cdot b2} \]
    2. Step-by-step derivation
      1. associate-/l*99.2%

        \[\leadsto \color{blue}{\frac{a1}{\frac{b1 \cdot b2}{a2}}} \]
      2. associate-/r/84.3%

        \[\leadsto \color{blue}{\frac{a1}{b1 \cdot b2} \cdot a2} \]
      3. *-commutative84.3%

        \[\leadsto \frac{a1}{\color{blue}{b2 \cdot b1}} \cdot a2 \]
    3. Applied egg-rr84.3%

      \[\leadsto \color{blue}{\frac{a1}{b2 \cdot b1} \cdot a2} \]

    if -4.80000000000000028e256 < b1

    1. Initial program 84.4%

      \[\frac{a1 \cdot a2}{b1 \cdot b2} \]
    2. Step-by-step derivation
      1. times-frac86.6%

        \[\leadsto \color{blue}{\frac{a1}{b1} \cdot \frac{a2}{b2}} \]
      2. associate-*l/87.9%

        \[\leadsto \color{blue}{\frac{a1 \cdot \frac{a2}{b2}}{b1}} \]
      3. associate-*r/89.8%

        \[\leadsto \color{blue}{a1 \cdot \frac{\frac{a2}{b2}}{b1}} \]
    3. Simplified89.8%

      \[\leadsto \color{blue}{a1 \cdot \frac{\frac{a2}{b2}}{b1}} \]
  3. Recombined 2 regimes into one program.
  4. Final simplification89.7%

    \[\leadsto \begin{array}{l} \mathbf{if}\;b1 \leq -4.8 \cdot 10^{+256}:\\ \;\;\;\;a2 \cdot \frac{a1}{b1 \cdot b2}\\ \mathbf{else}:\\ \;\;\;\;a1 \cdot \frac{\frac{a2}{b2}}{b1}\\ \end{array} \]

Alternative 9: 86.3% accurate, 1.0× speedup?

\[\begin{array}{l} [a1, a2] = \mathsf{sort}([a1, a2])\\ [b1, b2] = \mathsf{sort}([b1, b2])\\ \\ a1 \cdot \frac{\frac{a2}{b2}}{b1} \end{array} \]
NOTE: a1 and a2 should be sorted in increasing order before calling this function.
NOTE: b1 and b2 should be sorted in increasing order before calling this function.
(FPCore (a1 a2 b1 b2) :precision binary64 (* a1 (/ (/ a2 b2) b1)))
assert(a1 < a2);
assert(b1 < b2);
double code(double a1, double a2, double b1, double b2) {
	return a1 * ((a2 / b2) / b1);
}
NOTE: a1 and a2 should be sorted in increasing order before calling this function.
NOTE: b1 and b2 should be sorted in increasing order before calling this function.
real(8) function code(a1, a2, b1, b2)
    real(8), intent (in) :: a1
    real(8), intent (in) :: a2
    real(8), intent (in) :: b1
    real(8), intent (in) :: b2
    code = a1 * ((a2 / b2) / b1)
end function
assert a1 < a2;
assert b1 < b2;
public static double code(double a1, double a2, double b1, double b2) {
	return a1 * ((a2 / b2) / b1);
}
[a1, a2] = sort([a1, a2])
[b1, b2] = sort([b1, b2])
def code(a1, a2, b1, b2):
	return a1 * ((a2 / b2) / b1)
a1, a2 = sort([a1, a2])
b1, b2 = sort([b1, b2])
function code(a1, a2, b1, b2)
	return Float64(a1 * Float64(Float64(a2 / b2) / b1))
end
a1, a2 = num2cell(sort([a1, a2])){:}
b1, b2 = num2cell(sort([b1, b2])){:}
function tmp = code(a1, a2, b1, b2)
	tmp = a1 * ((a2 / b2) / b1);
end
NOTE: a1 and a2 should be sorted in increasing order before calling this function.
NOTE: b1 and b2 should be sorted in increasing order before calling this function.
code[a1_, a2_, b1_, b2_] := N[(a1 * N[(N[(a2 / b2), $MachinePrecision] / b1), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
[a1, a2] = \mathsf{sort}([a1, a2])\\
[b1, b2] = \mathsf{sort}([b1, b2])\\
\\
a1 \cdot \frac{\frac{a2}{b2}}{b1}
\end{array}
Derivation
  1. Initial program 84.4%

    \[\frac{a1 \cdot a2}{b1 \cdot b2} \]
  2. Step-by-step derivation
    1. times-frac86.2%

      \[\leadsto \color{blue}{\frac{a1}{b1} \cdot \frac{a2}{b2}} \]
    2. associate-*l/87.8%

      \[\leadsto \color{blue}{\frac{a1 \cdot \frac{a2}{b2}}{b1}} \]
    3. associate-*r/90.1%

      \[\leadsto \color{blue}{a1 \cdot \frac{\frac{a2}{b2}}{b1}} \]
  3. Simplified90.1%

    \[\leadsto \color{blue}{a1 \cdot \frac{\frac{a2}{b2}}{b1}} \]
  4. Final simplification90.1%

    \[\leadsto a1 \cdot \frac{\frac{a2}{b2}}{b1} \]

Developer target: 86.5% accurate, 1.0× speedup?

\[\begin{array}{l} \\ \frac{a1}{b1} \cdot \frac{a2}{b2} \end{array} \]
(FPCore (a1 a2 b1 b2) :precision binary64 (* (/ a1 b1) (/ a2 b2)))
double code(double a1, double a2, double b1, double b2) {
	return (a1 / b1) * (a2 / b2);
}
real(8) function code(a1, a2, b1, b2)
    real(8), intent (in) :: a1
    real(8), intent (in) :: a2
    real(8), intent (in) :: b1
    real(8), intent (in) :: b2
    code = (a1 / b1) * (a2 / b2)
end function
public static double code(double a1, double a2, double b1, double b2) {
	return (a1 / b1) * (a2 / b2);
}
def code(a1, a2, b1, b2):
	return (a1 / b1) * (a2 / b2)
function code(a1, a2, b1, b2)
	return Float64(Float64(a1 / b1) * Float64(a2 / b2))
end
function tmp = code(a1, a2, b1, b2)
	tmp = (a1 / b1) * (a2 / b2);
end
code[a1_, a2_, b1_, b2_] := N[(N[(a1 / b1), $MachinePrecision] * N[(a2 / b2), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}

\\
\frac{a1}{b1} \cdot \frac{a2}{b2}
\end{array}

Reproduce

?
herbie shell --seed 2023307 
(FPCore (a1 a2 b1 b2)
  :name "Quotient of products"
  :precision binary64

  :herbie-target
  (* (/ a1 b1) (/ a2 b2))

  (/ (* a1 a2) (* b1 b2)))