Octave 3.8, jcobi/1

Percentage Accurate: 74.5% → 99.9%
Time: 2.8s
Alternatives: 11
Speedup: 1.0×

Specification

?
\[\alpha > -1 \land \beta > -1\]
\[\begin{array}{l} \\ \frac{\frac{\beta - \alpha}{\left(\alpha + \beta\right) + 2} + 1}{2} \end{array} \]
(FPCore (alpha beta)
 :precision binary64
 (/ (+ (/ (- beta alpha) (+ (+ alpha beta) 2.0)) 1.0) 2.0))
double code(double alpha, double beta) {
	return (((beta - alpha) / ((alpha + beta) + 2.0)) + 1.0) / 2.0;
}
module fmin_fmax_functions
    implicit none
    private
    public fmax
    public fmin

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

real(8) function code(alpha, beta)
use fmin_fmax_functions
    real(8), intent (in) :: alpha
    real(8), intent (in) :: beta
    code = (((beta - alpha) / ((alpha + beta) + 2.0d0)) + 1.0d0) / 2.0d0
end function
public static double code(double alpha, double beta) {
	return (((beta - alpha) / ((alpha + beta) + 2.0)) + 1.0) / 2.0;
}
def code(alpha, beta):
	return (((beta - alpha) / ((alpha + beta) + 2.0)) + 1.0) / 2.0
function code(alpha, beta)
	return Float64(Float64(Float64(Float64(beta - alpha) / Float64(Float64(alpha + beta) + 2.0)) + 1.0) / 2.0)
end
function tmp = code(alpha, beta)
	tmp = (((beta - alpha) / ((alpha + beta) + 2.0)) + 1.0) / 2.0;
end
code[alpha_, beta_] := N[(N[(N[(N[(beta - alpha), $MachinePrecision] / N[(N[(alpha + beta), $MachinePrecision] + 2.0), $MachinePrecision]), $MachinePrecision] + 1.0), $MachinePrecision] / 2.0), $MachinePrecision]
\begin{array}{l}

\\
\frac{\frac{\beta - \alpha}{\left(\alpha + \beta\right) + 2} + 1}{2}
\end{array}

Local Percentage Accuracy vs ?

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

Accuracy vs Speed?

Herbie found 11 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: 74.5% accurate, 1.0× speedup?

\[\begin{array}{l} \\ \frac{\frac{\beta - \alpha}{\left(\alpha + \beta\right) + 2} + 1}{2} \end{array} \]
(FPCore (alpha beta)
 :precision binary64
 (/ (+ (/ (- beta alpha) (+ (+ alpha beta) 2.0)) 1.0) 2.0))
double code(double alpha, double beta) {
	return (((beta - alpha) / ((alpha + beta) + 2.0)) + 1.0) / 2.0;
}
module fmin_fmax_functions
    implicit none
    private
    public fmax
    public fmin

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

real(8) function code(alpha, beta)
use fmin_fmax_functions
    real(8), intent (in) :: alpha
    real(8), intent (in) :: beta
    code = (((beta - alpha) / ((alpha + beta) + 2.0d0)) + 1.0d0) / 2.0d0
end function
public static double code(double alpha, double beta) {
	return (((beta - alpha) / ((alpha + beta) + 2.0)) + 1.0) / 2.0;
}
def code(alpha, beta):
	return (((beta - alpha) / ((alpha + beta) + 2.0)) + 1.0) / 2.0
function code(alpha, beta)
	return Float64(Float64(Float64(Float64(beta - alpha) / Float64(Float64(alpha + beta) + 2.0)) + 1.0) / 2.0)
end
function tmp = code(alpha, beta)
	tmp = (((beta - alpha) / ((alpha + beta) + 2.0)) + 1.0) / 2.0;
end
code[alpha_, beta_] := N[(N[(N[(N[(beta - alpha), $MachinePrecision] / N[(N[(alpha + beta), $MachinePrecision] + 2.0), $MachinePrecision]), $MachinePrecision] + 1.0), $MachinePrecision] / 2.0), $MachinePrecision]
\begin{array}{l}

\\
\frac{\frac{\beta - \alpha}{\left(\alpha + \beta\right) + 2} + 1}{2}
\end{array}

Alternative 1: 99.9% accurate, 0.7× speedup?

\[\begin{array}{l} \\ \frac{\frac{\mathsf{fma}\left(2, \beta, 2 \cdot \left(2 + \beta\right)\right)}{\left(\left(\alpha + \beta\right) + 2\right) \cdot 2}}{2} \end{array} \]
(FPCore (alpha beta)
 :precision binary64
 (/
  (/ (fma 2.0 beta (* 2.0 (+ 2.0 beta))) (* (+ (+ alpha beta) 2.0) 2.0))
  2.0))
double code(double alpha, double beta) {
	return (fma(2.0, beta, (2.0 * (2.0 + beta))) / (((alpha + beta) + 2.0) * 2.0)) / 2.0;
}
function code(alpha, beta)
	return Float64(Float64(fma(2.0, beta, Float64(2.0 * Float64(2.0 + beta))) / Float64(Float64(Float64(alpha + beta) + 2.0) * 2.0)) / 2.0)
end
code[alpha_, beta_] := N[(N[(N[(2.0 * beta + N[(2.0 * N[(2.0 + beta), $MachinePrecision]), $MachinePrecision]), $MachinePrecision] / N[(N[(N[(alpha + beta), $MachinePrecision] + 2.0), $MachinePrecision] * 2.0), $MachinePrecision]), $MachinePrecision] / 2.0), $MachinePrecision]
\begin{array}{l}

\\
\frac{\frac{\mathsf{fma}\left(2, \beta, 2 \cdot \left(2 + \beta\right)\right)}{\left(\left(\alpha + \beta\right) + 2\right) \cdot 2}}{2}
\end{array}
Derivation
  1. Initial program 74.5%

    \[\frac{\frac{\beta - \alpha}{\left(\alpha + \beta\right) + 2} + 1}{2} \]
  2. Applied rewrites74.7%

    \[\leadsto \frac{\color{blue}{\frac{\mathsf{fma}\left(\beta - \alpha, 2, \left(\left(\alpha + \beta\right) + 2\right) \cdot 2\right)}{\left(\left(\alpha + \beta\right) + 2\right) \cdot 2}}}{2} \]
  3. Taylor expanded in alpha around 0

    \[\leadsto \frac{\frac{\color{blue}{2 \cdot \beta + 2 \cdot \left(2 + \beta\right)}}{\left(\left(\alpha + \beta\right) + 2\right) \cdot 2}}{2} \]
  4. Applied rewrites99.9%

    \[\leadsto \frac{\frac{\color{blue}{\mathsf{fma}\left(2, \beta, 2 \cdot \left(2 + \beta\right)\right)}}{\left(\left(\alpha + \beta\right) + 2\right) \cdot 2}}{2} \]
  5. Add Preprocessing

Alternative 2: 97.5% accurate, 0.3× speedup?

\[\begin{array}{l} \\ \begin{array}{l} t_0 := \frac{\frac{\beta - \alpha}{\left(\alpha + \beta\right) + 2} + 1}{2}\\ \mathbf{if}\;t\_0 \leq 0.005:\\ \;\;\;\;\frac{1 + \beta}{\alpha}\\ \mathbf{elif}\;t\_0 \leq 0.6:\\ \;\;\;\;\mathsf{fma}\left(0.25, \beta, 0.5\right)\\ \mathbf{else}:\\ \;\;\;\;\mathsf{fma}\left(\frac{\alpha + \alpha}{\beta}, -0.5, 1\right)\\ \end{array} \end{array} \]
(FPCore (alpha beta)
 :precision binary64
 (let* ((t_0 (/ (+ (/ (- beta alpha) (+ (+ alpha beta) 2.0)) 1.0) 2.0)))
   (if (<= t_0 0.005)
     (/ (+ 1.0 beta) alpha)
     (if (<= t_0 0.6)
       (fma 0.25 beta 0.5)
       (fma (/ (+ alpha alpha) beta) -0.5 1.0)))))
double code(double alpha, double beta) {
	double t_0 = (((beta - alpha) / ((alpha + beta) + 2.0)) + 1.0) / 2.0;
	double tmp;
	if (t_0 <= 0.005) {
		tmp = (1.0 + beta) / alpha;
	} else if (t_0 <= 0.6) {
		tmp = fma(0.25, beta, 0.5);
	} else {
		tmp = fma(((alpha + alpha) / beta), -0.5, 1.0);
	}
	return tmp;
}
function code(alpha, beta)
	t_0 = Float64(Float64(Float64(Float64(beta - alpha) / Float64(Float64(alpha + beta) + 2.0)) + 1.0) / 2.0)
	tmp = 0.0
	if (t_0 <= 0.005)
		tmp = Float64(Float64(1.0 + beta) / alpha);
	elseif (t_0 <= 0.6)
		tmp = fma(0.25, beta, 0.5);
	else
		tmp = fma(Float64(Float64(alpha + alpha) / beta), -0.5, 1.0);
	end
	return tmp
end
code[alpha_, beta_] := Block[{t$95$0 = N[(N[(N[(N[(beta - alpha), $MachinePrecision] / N[(N[(alpha + beta), $MachinePrecision] + 2.0), $MachinePrecision]), $MachinePrecision] + 1.0), $MachinePrecision] / 2.0), $MachinePrecision]}, If[LessEqual[t$95$0, 0.005], N[(N[(1.0 + beta), $MachinePrecision] / alpha), $MachinePrecision], If[LessEqual[t$95$0, 0.6], N[(0.25 * beta + 0.5), $MachinePrecision], N[(N[(N[(alpha + alpha), $MachinePrecision] / beta), $MachinePrecision] * -0.5 + 1.0), $MachinePrecision]]]]
\begin{array}{l}

\\
\begin{array}{l}
t_0 := \frac{\frac{\beta - \alpha}{\left(\alpha + \beta\right) + 2} + 1}{2}\\
\mathbf{if}\;t\_0 \leq 0.005:\\
\;\;\;\;\frac{1 + \beta}{\alpha}\\

\mathbf{elif}\;t\_0 \leq 0.6:\\
\;\;\;\;\mathsf{fma}\left(0.25, \beta, 0.5\right)\\

\mathbf{else}:\\
\;\;\;\;\mathsf{fma}\left(\frac{\alpha + \alpha}{\beta}, -0.5, 1\right)\\


\end{array}
\end{array}
Derivation
  1. Split input into 3 regimes
  2. if (/.f64 (+.f64 (/.f64 (-.f64 beta alpha) (+.f64 (+.f64 alpha beta) #s(literal 2 binary64))) #s(literal 1 binary64)) #s(literal 2 binary64)) < 0.0050000000000000001

    1. Initial program 8.1%

      \[\frac{\frac{\beta - \alpha}{\left(\alpha + \beta\right) + 2} + 1}{2} \]
    2. Taylor expanded in alpha around inf

      \[\leadsto \color{blue}{\frac{1}{2} \cdot \frac{2 + 2 \cdot \beta}{\alpha}} \]
    3. Applied rewrites98.2%

      \[\leadsto \color{blue}{\frac{\mathsf{fma}\left(2, \beta, 2\right) \cdot 0.5}{\alpha}} \]
    4. Taylor expanded in beta around 0

      \[\leadsto \frac{1 + \beta}{\alpha} \]
    5. Applied rewrites98.2%

      \[\leadsto \frac{1 + \beta}{\alpha} \]

    if 0.0050000000000000001 < (/.f64 (+.f64 (/.f64 (-.f64 beta alpha) (+.f64 (+.f64 alpha beta) #s(literal 2 binary64))) #s(literal 1 binary64)) #s(literal 2 binary64)) < 0.599999999999999978

    1. Initial program 100.0%

      \[\frac{\frac{\beta - \alpha}{\left(\alpha + \beta\right) + 2} + 1}{2} \]
    2. Taylor expanded in alpha around 0

      \[\leadsto \color{blue}{\frac{1}{2} \cdot \left(1 + \frac{\beta}{2 + \beta}\right)} \]
    3. Applied rewrites97.9%

      \[\leadsto \color{blue}{\left(\frac{\beta}{2 + \beta} + 1\right) \cdot 0.5} \]
    4. Taylor expanded in beta around 0

      \[\leadsto \frac{1}{2} \]
    5. Applied rewrites96.0%

      \[\leadsto 0.5 \]
    6. Taylor expanded in beta around 0

      \[\leadsto \frac{1}{2} + \color{blue}{\frac{1}{4} \cdot \beta} \]
    7. Applied rewrites97.0%

      \[\leadsto \mathsf{fma}\left(0.25, \color{blue}{\beta}, 0.5\right) \]

    if 0.599999999999999978 < (/.f64 (+.f64 (/.f64 (-.f64 beta alpha) (+.f64 (+.f64 alpha beta) #s(literal 2 binary64))) #s(literal 1 binary64)) #s(literal 2 binary64))

    1. Initial program 100.0%

      \[\frac{\frac{\beta - \alpha}{\left(\alpha + \beta\right) + 2} + 1}{2} \]
    2. Taylor expanded in beta around inf

      \[\leadsto \color{blue}{1 + \frac{-1}{2} \cdot \frac{2 + 2 \cdot \alpha}{\beta}} \]
    3. Applied rewrites98.6%

      \[\leadsto \color{blue}{\mathsf{fma}\left(\frac{\mathsf{fma}\left(2, \alpha, 2\right)}{\beta}, -0.5, 1\right)} \]
    4. Taylor expanded in alpha around inf

      \[\leadsto \mathsf{fma}\left(\frac{2 \cdot \alpha}{\beta}, \frac{-1}{2}, 1\right) \]
    5. Applied rewrites97.7%

      \[\leadsto \mathsf{fma}\left(\frac{\alpha + \alpha}{\beta}, -0.5, 1\right) \]
  3. Recombined 3 regimes into one program.
  4. Add Preprocessing

Alternative 3: 97.6% accurate, 0.4× speedup?

\[\begin{array}{l} \\ \begin{array}{l} t_0 := \frac{\frac{\beta - \alpha}{\left(\alpha + \beta\right) + 2} + 1}{2}\\ \mathbf{if}\;t\_0 \leq 0.005:\\ \;\;\;\;\frac{1 + \beta}{\alpha}\\ \mathbf{elif}\;t\_0 \leq 0.6:\\ \;\;\;\;\mathsf{fma}\left(0.25, \beta, 0.5\right)\\ \mathbf{else}:\\ \;\;\;\;\mathsf{fma}\left(\frac{2}{\beta}, -0.5, 1\right)\\ \end{array} \end{array} \]
(FPCore (alpha beta)
 :precision binary64
 (let* ((t_0 (/ (+ (/ (- beta alpha) (+ (+ alpha beta) 2.0)) 1.0) 2.0)))
   (if (<= t_0 0.005)
     (/ (+ 1.0 beta) alpha)
     (if (<= t_0 0.6) (fma 0.25 beta 0.5) (fma (/ 2.0 beta) -0.5 1.0)))))
double code(double alpha, double beta) {
	double t_0 = (((beta - alpha) / ((alpha + beta) + 2.0)) + 1.0) / 2.0;
	double tmp;
	if (t_0 <= 0.005) {
		tmp = (1.0 + beta) / alpha;
	} else if (t_0 <= 0.6) {
		tmp = fma(0.25, beta, 0.5);
	} else {
		tmp = fma((2.0 / beta), -0.5, 1.0);
	}
	return tmp;
}
function code(alpha, beta)
	t_0 = Float64(Float64(Float64(Float64(beta - alpha) / Float64(Float64(alpha + beta) + 2.0)) + 1.0) / 2.0)
	tmp = 0.0
	if (t_0 <= 0.005)
		tmp = Float64(Float64(1.0 + beta) / alpha);
	elseif (t_0 <= 0.6)
		tmp = fma(0.25, beta, 0.5);
	else
		tmp = fma(Float64(2.0 / beta), -0.5, 1.0);
	end
	return tmp
end
code[alpha_, beta_] := Block[{t$95$0 = N[(N[(N[(N[(beta - alpha), $MachinePrecision] / N[(N[(alpha + beta), $MachinePrecision] + 2.0), $MachinePrecision]), $MachinePrecision] + 1.0), $MachinePrecision] / 2.0), $MachinePrecision]}, If[LessEqual[t$95$0, 0.005], N[(N[(1.0 + beta), $MachinePrecision] / alpha), $MachinePrecision], If[LessEqual[t$95$0, 0.6], N[(0.25 * beta + 0.5), $MachinePrecision], N[(N[(2.0 / beta), $MachinePrecision] * -0.5 + 1.0), $MachinePrecision]]]]
\begin{array}{l}

\\
\begin{array}{l}
t_0 := \frac{\frac{\beta - \alpha}{\left(\alpha + \beta\right) + 2} + 1}{2}\\
\mathbf{if}\;t\_0 \leq 0.005:\\
\;\;\;\;\frac{1 + \beta}{\alpha}\\

\mathbf{elif}\;t\_0 \leq 0.6:\\
\;\;\;\;\mathsf{fma}\left(0.25, \beta, 0.5\right)\\

\mathbf{else}:\\
\;\;\;\;\mathsf{fma}\left(\frac{2}{\beta}, -0.5, 1\right)\\


\end{array}
\end{array}
Derivation
  1. Split input into 3 regimes
  2. if (/.f64 (+.f64 (/.f64 (-.f64 beta alpha) (+.f64 (+.f64 alpha beta) #s(literal 2 binary64))) #s(literal 1 binary64)) #s(literal 2 binary64)) < 0.0050000000000000001

    1. Initial program 8.1%

      \[\frac{\frac{\beta - \alpha}{\left(\alpha + \beta\right) + 2} + 1}{2} \]
    2. Taylor expanded in alpha around inf

      \[\leadsto \color{blue}{\frac{1}{2} \cdot \frac{2 + 2 \cdot \beta}{\alpha}} \]
    3. Applied rewrites98.2%

      \[\leadsto \color{blue}{\frac{\mathsf{fma}\left(2, \beta, 2\right) \cdot 0.5}{\alpha}} \]
    4. Taylor expanded in beta around 0

      \[\leadsto \frac{1 + \beta}{\alpha} \]
    5. Applied rewrites98.2%

      \[\leadsto \frac{1 + \beta}{\alpha} \]

    if 0.0050000000000000001 < (/.f64 (+.f64 (/.f64 (-.f64 beta alpha) (+.f64 (+.f64 alpha beta) #s(literal 2 binary64))) #s(literal 1 binary64)) #s(literal 2 binary64)) < 0.599999999999999978

    1. Initial program 100.0%

      \[\frac{\frac{\beta - \alpha}{\left(\alpha + \beta\right) + 2} + 1}{2} \]
    2. Taylor expanded in alpha around 0

      \[\leadsto \color{blue}{\frac{1}{2} \cdot \left(1 + \frac{\beta}{2 + \beta}\right)} \]
    3. Applied rewrites97.9%

      \[\leadsto \color{blue}{\left(\frac{\beta}{2 + \beta} + 1\right) \cdot 0.5} \]
    4. Taylor expanded in beta around 0

      \[\leadsto \frac{1}{2} \]
    5. Applied rewrites96.0%

      \[\leadsto 0.5 \]
    6. Taylor expanded in beta around 0

      \[\leadsto \frac{1}{2} + \color{blue}{\frac{1}{4} \cdot \beta} \]
    7. Applied rewrites97.0%

      \[\leadsto \mathsf{fma}\left(0.25, \color{blue}{\beta}, 0.5\right) \]

    if 0.599999999999999978 < (/.f64 (+.f64 (/.f64 (-.f64 beta alpha) (+.f64 (+.f64 alpha beta) #s(literal 2 binary64))) #s(literal 1 binary64)) #s(literal 2 binary64))

    1. Initial program 100.0%

      \[\frac{\frac{\beta - \alpha}{\left(\alpha + \beta\right) + 2} + 1}{2} \]
    2. Taylor expanded in beta around inf

      \[\leadsto \color{blue}{1 + \frac{-1}{2} \cdot \frac{2 + 2 \cdot \alpha}{\beta}} \]
    3. Applied rewrites98.6%

      \[\leadsto \color{blue}{\mathsf{fma}\left(\frac{\mathsf{fma}\left(2, \alpha, 2\right)}{\beta}, -0.5, 1\right)} \]
    4. Taylor expanded in alpha around 0

      \[\leadsto \mathsf{fma}\left(\frac{2}{\beta}, \frac{-1}{2}, 1\right) \]
    5. Applied rewrites98.2%

      \[\leadsto \mathsf{fma}\left(\frac{2}{\beta}, -0.5, 1\right) \]
  3. Recombined 3 regimes into one program.
  4. Add Preprocessing

Alternative 4: 97.4% accurate, 0.4× speedup?

\[\begin{array}{l} \\ \begin{array}{l} t_0 := \frac{\frac{\beta - \alpha}{\left(\alpha + \beta\right) + 2} + 1}{2}\\ \mathbf{if}\;t\_0 \leq 0.005:\\ \;\;\;\;\frac{1 + \beta}{\alpha}\\ \mathbf{elif}\;t\_0 \leq 0.6:\\ \;\;\;\;\mathsf{fma}\left(0.25, \beta, 0.5\right)\\ \mathbf{else}:\\ \;\;\;\;1\\ \end{array} \end{array} \]
(FPCore (alpha beta)
 :precision binary64
 (let* ((t_0 (/ (+ (/ (- beta alpha) (+ (+ alpha beta) 2.0)) 1.0) 2.0)))
   (if (<= t_0 0.005)
     (/ (+ 1.0 beta) alpha)
     (if (<= t_0 0.6) (fma 0.25 beta 0.5) 1.0))))
double code(double alpha, double beta) {
	double t_0 = (((beta - alpha) / ((alpha + beta) + 2.0)) + 1.0) / 2.0;
	double tmp;
	if (t_0 <= 0.005) {
		tmp = (1.0 + beta) / alpha;
	} else if (t_0 <= 0.6) {
		tmp = fma(0.25, beta, 0.5);
	} else {
		tmp = 1.0;
	}
	return tmp;
}
function code(alpha, beta)
	t_0 = Float64(Float64(Float64(Float64(beta - alpha) / Float64(Float64(alpha + beta) + 2.0)) + 1.0) / 2.0)
	tmp = 0.0
	if (t_0 <= 0.005)
		tmp = Float64(Float64(1.0 + beta) / alpha);
	elseif (t_0 <= 0.6)
		tmp = fma(0.25, beta, 0.5);
	else
		tmp = 1.0;
	end
	return tmp
end
code[alpha_, beta_] := Block[{t$95$0 = N[(N[(N[(N[(beta - alpha), $MachinePrecision] / N[(N[(alpha + beta), $MachinePrecision] + 2.0), $MachinePrecision]), $MachinePrecision] + 1.0), $MachinePrecision] / 2.0), $MachinePrecision]}, If[LessEqual[t$95$0, 0.005], N[(N[(1.0 + beta), $MachinePrecision] / alpha), $MachinePrecision], If[LessEqual[t$95$0, 0.6], N[(0.25 * beta + 0.5), $MachinePrecision], 1.0]]]
\begin{array}{l}

\\
\begin{array}{l}
t_0 := \frac{\frac{\beta - \alpha}{\left(\alpha + \beta\right) + 2} + 1}{2}\\
\mathbf{if}\;t\_0 \leq 0.005:\\
\;\;\;\;\frac{1 + \beta}{\alpha}\\

\mathbf{elif}\;t\_0 \leq 0.6:\\
\;\;\;\;\mathsf{fma}\left(0.25, \beta, 0.5\right)\\

\mathbf{else}:\\
\;\;\;\;1\\


\end{array}
\end{array}
Derivation
  1. Split input into 3 regimes
  2. if (/.f64 (+.f64 (/.f64 (-.f64 beta alpha) (+.f64 (+.f64 alpha beta) #s(literal 2 binary64))) #s(literal 1 binary64)) #s(literal 2 binary64)) < 0.0050000000000000001

    1. Initial program 8.1%

      \[\frac{\frac{\beta - \alpha}{\left(\alpha + \beta\right) + 2} + 1}{2} \]
    2. Taylor expanded in alpha around inf

      \[\leadsto \color{blue}{\frac{1}{2} \cdot \frac{2 + 2 \cdot \beta}{\alpha}} \]
    3. Applied rewrites98.2%

      \[\leadsto \color{blue}{\frac{\mathsf{fma}\left(2, \beta, 2\right) \cdot 0.5}{\alpha}} \]
    4. Taylor expanded in beta around 0

      \[\leadsto \frac{1 + \beta}{\alpha} \]
    5. Applied rewrites98.2%

      \[\leadsto \frac{1 + \beta}{\alpha} \]

    if 0.0050000000000000001 < (/.f64 (+.f64 (/.f64 (-.f64 beta alpha) (+.f64 (+.f64 alpha beta) #s(literal 2 binary64))) #s(literal 1 binary64)) #s(literal 2 binary64)) < 0.599999999999999978

    1. Initial program 100.0%

      \[\frac{\frac{\beta - \alpha}{\left(\alpha + \beta\right) + 2} + 1}{2} \]
    2. Taylor expanded in alpha around 0

      \[\leadsto \color{blue}{\frac{1}{2} \cdot \left(1 + \frac{\beta}{2 + \beta}\right)} \]
    3. Applied rewrites97.9%

      \[\leadsto \color{blue}{\left(\frac{\beta}{2 + \beta} + 1\right) \cdot 0.5} \]
    4. Taylor expanded in beta around 0

      \[\leadsto \frac{1}{2} \]
    5. Applied rewrites96.0%

      \[\leadsto 0.5 \]
    6. Taylor expanded in beta around 0

      \[\leadsto \frac{1}{2} + \color{blue}{\frac{1}{4} \cdot \beta} \]
    7. Applied rewrites97.0%

      \[\leadsto \mathsf{fma}\left(0.25, \color{blue}{\beta}, 0.5\right) \]

    if 0.599999999999999978 < (/.f64 (+.f64 (/.f64 (-.f64 beta alpha) (+.f64 (+.f64 alpha beta) #s(literal 2 binary64))) #s(literal 1 binary64)) #s(literal 2 binary64))

    1. Initial program 100.0%

      \[\frac{\frac{\beta - \alpha}{\left(\alpha + \beta\right) + 2} + 1}{2} \]
    2. Taylor expanded in beta around inf

      \[\leadsto \color{blue}{1} \]
    3. Applied rewrites97.4%

      \[\leadsto \color{blue}{1} \]
  3. Recombined 3 regimes into one program.
  4. Add Preprocessing

Alternative 5: 91.9% accurate, 0.4× speedup?

\[\begin{array}{l} \\ \begin{array}{l} t_0 := \frac{\frac{\beta - \alpha}{\left(\alpha + \beta\right) + 2} + 1}{2}\\ \mathbf{if}\;t\_0 \leq 0.005:\\ \;\;\;\;\frac{1}{\alpha}\\ \mathbf{elif}\;t\_0 \leq 0.6:\\ \;\;\;\;\mathsf{fma}\left(0.25, \beta, 0.5\right)\\ \mathbf{else}:\\ \;\;\;\;1\\ \end{array} \end{array} \]
(FPCore (alpha beta)
 :precision binary64
 (let* ((t_0 (/ (+ (/ (- beta alpha) (+ (+ alpha beta) 2.0)) 1.0) 2.0)))
   (if (<= t_0 0.005)
     (/ 1.0 alpha)
     (if (<= t_0 0.6) (fma 0.25 beta 0.5) 1.0))))
double code(double alpha, double beta) {
	double t_0 = (((beta - alpha) / ((alpha + beta) + 2.0)) + 1.0) / 2.0;
	double tmp;
	if (t_0 <= 0.005) {
		tmp = 1.0 / alpha;
	} else if (t_0 <= 0.6) {
		tmp = fma(0.25, beta, 0.5);
	} else {
		tmp = 1.0;
	}
	return tmp;
}
function code(alpha, beta)
	t_0 = Float64(Float64(Float64(Float64(beta - alpha) / Float64(Float64(alpha + beta) + 2.0)) + 1.0) / 2.0)
	tmp = 0.0
	if (t_0 <= 0.005)
		tmp = Float64(1.0 / alpha);
	elseif (t_0 <= 0.6)
		tmp = fma(0.25, beta, 0.5);
	else
		tmp = 1.0;
	end
	return tmp
end
code[alpha_, beta_] := Block[{t$95$0 = N[(N[(N[(N[(beta - alpha), $MachinePrecision] / N[(N[(alpha + beta), $MachinePrecision] + 2.0), $MachinePrecision]), $MachinePrecision] + 1.0), $MachinePrecision] / 2.0), $MachinePrecision]}, If[LessEqual[t$95$0, 0.005], N[(1.0 / alpha), $MachinePrecision], If[LessEqual[t$95$0, 0.6], N[(0.25 * beta + 0.5), $MachinePrecision], 1.0]]]
\begin{array}{l}

\\
\begin{array}{l}
t_0 := \frac{\frac{\beta - \alpha}{\left(\alpha + \beta\right) + 2} + 1}{2}\\
\mathbf{if}\;t\_0 \leq 0.005:\\
\;\;\;\;\frac{1}{\alpha}\\

\mathbf{elif}\;t\_0 \leq 0.6:\\
\;\;\;\;\mathsf{fma}\left(0.25, \beta, 0.5\right)\\

\mathbf{else}:\\
\;\;\;\;1\\


\end{array}
\end{array}
Derivation
  1. Split input into 3 regimes
  2. if (/.f64 (+.f64 (/.f64 (-.f64 beta alpha) (+.f64 (+.f64 alpha beta) #s(literal 2 binary64))) #s(literal 1 binary64)) #s(literal 2 binary64)) < 0.0050000000000000001

    1. Initial program 8.1%

      \[\frac{\frac{\beta - \alpha}{\left(\alpha + \beta\right) + 2} + 1}{2} \]
    2. Taylor expanded in alpha around inf

      \[\leadsto \color{blue}{\frac{1}{2} \cdot \frac{2 + 2 \cdot \beta}{\alpha}} \]
    3. Applied rewrites98.2%

      \[\leadsto \color{blue}{\frac{\mathsf{fma}\left(2, \beta, 2\right) \cdot 0.5}{\alpha}} \]
    4. Taylor expanded in beta around 0

      \[\leadsto \frac{1}{\alpha} \]
    5. Applied rewrites78.4%

      \[\leadsto \frac{1}{\alpha} \]

    if 0.0050000000000000001 < (/.f64 (+.f64 (/.f64 (-.f64 beta alpha) (+.f64 (+.f64 alpha beta) #s(literal 2 binary64))) #s(literal 1 binary64)) #s(literal 2 binary64)) < 0.599999999999999978

    1. Initial program 100.0%

      \[\frac{\frac{\beta - \alpha}{\left(\alpha + \beta\right) + 2} + 1}{2} \]
    2. Taylor expanded in alpha around 0

      \[\leadsto \color{blue}{\frac{1}{2} \cdot \left(1 + \frac{\beta}{2 + \beta}\right)} \]
    3. Applied rewrites97.9%

      \[\leadsto \color{blue}{\left(\frac{\beta}{2 + \beta} + 1\right) \cdot 0.5} \]
    4. Taylor expanded in beta around 0

      \[\leadsto \frac{1}{2} \]
    5. Applied rewrites96.0%

      \[\leadsto 0.5 \]
    6. Taylor expanded in beta around 0

      \[\leadsto \frac{1}{2} + \color{blue}{\frac{1}{4} \cdot \beta} \]
    7. Applied rewrites97.0%

      \[\leadsto \mathsf{fma}\left(0.25, \color{blue}{\beta}, 0.5\right) \]

    if 0.599999999999999978 < (/.f64 (+.f64 (/.f64 (-.f64 beta alpha) (+.f64 (+.f64 alpha beta) #s(literal 2 binary64))) #s(literal 1 binary64)) #s(literal 2 binary64))

    1. Initial program 100.0%

      \[\frac{\frac{\beta - \alpha}{\left(\alpha + \beta\right) + 2} + 1}{2} \]
    2. Taylor expanded in beta around inf

      \[\leadsto \color{blue}{1} \]
    3. Applied rewrites97.4%

      \[\leadsto \color{blue}{1} \]
  3. Recombined 3 regimes into one program.
  4. Add Preprocessing

Alternative 6: 98.3% accurate, 0.6× speedup?

\[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;\frac{\frac{\beta - \alpha}{\left(\alpha + \beta\right) + 2} + 1}{2} \leq 0.005:\\ \;\;\;\;\frac{1 + \beta}{\alpha}\\ \mathbf{else}:\\ \;\;\;\;\left(\frac{\beta}{2 + \beta} + 1\right) \cdot 0.5\\ \end{array} \end{array} \]
(FPCore (alpha beta)
 :precision binary64
 (if (<= (/ (+ (/ (- beta alpha) (+ (+ alpha beta) 2.0)) 1.0) 2.0) 0.005)
   (/ (+ 1.0 beta) alpha)
   (* (+ (/ beta (+ 2.0 beta)) 1.0) 0.5)))
double code(double alpha, double beta) {
	double tmp;
	if (((((beta - alpha) / ((alpha + beta) + 2.0)) + 1.0) / 2.0) <= 0.005) {
		tmp = (1.0 + beta) / alpha;
	} else {
		tmp = ((beta / (2.0 + beta)) + 1.0) * 0.5;
	}
	return tmp;
}
module fmin_fmax_functions
    implicit none
    private
    public fmax
    public fmin

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

real(8) function code(alpha, beta)
use fmin_fmax_functions
    real(8), intent (in) :: alpha
    real(8), intent (in) :: beta
    real(8) :: tmp
    if (((((beta - alpha) / ((alpha + beta) + 2.0d0)) + 1.0d0) / 2.0d0) <= 0.005d0) then
        tmp = (1.0d0 + beta) / alpha
    else
        tmp = ((beta / (2.0d0 + beta)) + 1.0d0) * 0.5d0
    end if
    code = tmp
end function
public static double code(double alpha, double beta) {
	double tmp;
	if (((((beta - alpha) / ((alpha + beta) + 2.0)) + 1.0) / 2.0) <= 0.005) {
		tmp = (1.0 + beta) / alpha;
	} else {
		tmp = ((beta / (2.0 + beta)) + 1.0) * 0.5;
	}
	return tmp;
}
def code(alpha, beta):
	tmp = 0
	if ((((beta - alpha) / ((alpha + beta) + 2.0)) + 1.0) / 2.0) <= 0.005:
		tmp = (1.0 + beta) / alpha
	else:
		tmp = ((beta / (2.0 + beta)) + 1.0) * 0.5
	return tmp
function code(alpha, beta)
	tmp = 0.0
	if (Float64(Float64(Float64(Float64(beta - alpha) / Float64(Float64(alpha + beta) + 2.0)) + 1.0) / 2.0) <= 0.005)
		tmp = Float64(Float64(1.0 + beta) / alpha);
	else
		tmp = Float64(Float64(Float64(beta / Float64(2.0 + beta)) + 1.0) * 0.5);
	end
	return tmp
end
function tmp_2 = code(alpha, beta)
	tmp = 0.0;
	if (((((beta - alpha) / ((alpha + beta) + 2.0)) + 1.0) / 2.0) <= 0.005)
		tmp = (1.0 + beta) / alpha;
	else
		tmp = ((beta / (2.0 + beta)) + 1.0) * 0.5;
	end
	tmp_2 = tmp;
end
code[alpha_, beta_] := If[LessEqual[N[(N[(N[(N[(beta - alpha), $MachinePrecision] / N[(N[(alpha + beta), $MachinePrecision] + 2.0), $MachinePrecision]), $MachinePrecision] + 1.0), $MachinePrecision] / 2.0), $MachinePrecision], 0.005], N[(N[(1.0 + beta), $MachinePrecision] / alpha), $MachinePrecision], N[(N[(N[(beta / N[(2.0 + beta), $MachinePrecision]), $MachinePrecision] + 1.0), $MachinePrecision] * 0.5), $MachinePrecision]]
\begin{array}{l}

\\
\begin{array}{l}
\mathbf{if}\;\frac{\frac{\beta - \alpha}{\left(\alpha + \beta\right) + 2} + 1}{2} \leq 0.005:\\
\;\;\;\;\frac{1 + \beta}{\alpha}\\

\mathbf{else}:\\
\;\;\;\;\left(\frac{\beta}{2 + \beta} + 1\right) \cdot 0.5\\


\end{array}
\end{array}
Derivation
  1. Split input into 2 regimes
  2. if (/.f64 (+.f64 (/.f64 (-.f64 beta alpha) (+.f64 (+.f64 alpha beta) #s(literal 2 binary64))) #s(literal 1 binary64)) #s(literal 2 binary64)) < 0.0050000000000000001

    1. Initial program 8.1%

      \[\frac{\frac{\beta - \alpha}{\left(\alpha + \beta\right) + 2} + 1}{2} \]
    2. Taylor expanded in alpha around inf

      \[\leadsto \color{blue}{\frac{1}{2} \cdot \frac{2 + 2 \cdot \beta}{\alpha}} \]
    3. Applied rewrites98.2%

      \[\leadsto \color{blue}{\frac{\mathsf{fma}\left(2, \beta, 2\right) \cdot 0.5}{\alpha}} \]
    4. Taylor expanded in beta around 0

      \[\leadsto \frac{1 + \beta}{\alpha} \]
    5. Applied rewrites98.2%

      \[\leadsto \frac{1 + \beta}{\alpha} \]

    if 0.0050000000000000001 < (/.f64 (+.f64 (/.f64 (-.f64 beta alpha) (+.f64 (+.f64 alpha beta) #s(literal 2 binary64))) #s(literal 1 binary64)) #s(literal 2 binary64))

    1. Initial program 100.0%

      \[\frac{\frac{\beta - \alpha}{\left(\alpha + \beta\right) + 2} + 1}{2} \]
    2. Taylor expanded in alpha around 0

      \[\leadsto \color{blue}{\frac{1}{2} \cdot \left(1 + \frac{\beta}{2 + \beta}\right)} \]
    3. Applied rewrites98.4%

      \[\leadsto \color{blue}{\left(\frac{\beta}{2 + \beta} + 1\right) \cdot 0.5} \]
  3. Recombined 2 regimes into one program.
  4. Add Preprocessing

Alternative 7: 71.2% accurate, 0.9× speedup?

\[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;\frac{\frac{\beta - \alpha}{\left(\alpha + \beta\right) + 2} + 1}{2} \leq 0.6:\\ \;\;\;\;0.5\\ \mathbf{else}:\\ \;\;\;\;1\\ \end{array} \end{array} \]
(FPCore (alpha beta)
 :precision binary64
 (if (<= (/ (+ (/ (- beta alpha) (+ (+ alpha beta) 2.0)) 1.0) 2.0) 0.6)
   0.5
   1.0))
double code(double alpha, double beta) {
	double tmp;
	if (((((beta - alpha) / ((alpha + beta) + 2.0)) + 1.0) / 2.0) <= 0.6) {
		tmp = 0.5;
	} else {
		tmp = 1.0;
	}
	return tmp;
}
module fmin_fmax_functions
    implicit none
    private
    public fmax
    public fmin

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

real(8) function code(alpha, beta)
use fmin_fmax_functions
    real(8), intent (in) :: alpha
    real(8), intent (in) :: beta
    real(8) :: tmp
    if (((((beta - alpha) / ((alpha + beta) + 2.0d0)) + 1.0d0) / 2.0d0) <= 0.6d0) then
        tmp = 0.5d0
    else
        tmp = 1.0d0
    end if
    code = tmp
end function
public static double code(double alpha, double beta) {
	double tmp;
	if (((((beta - alpha) / ((alpha + beta) + 2.0)) + 1.0) / 2.0) <= 0.6) {
		tmp = 0.5;
	} else {
		tmp = 1.0;
	}
	return tmp;
}
def code(alpha, beta):
	tmp = 0
	if ((((beta - alpha) / ((alpha + beta) + 2.0)) + 1.0) / 2.0) <= 0.6:
		tmp = 0.5
	else:
		tmp = 1.0
	return tmp
function code(alpha, beta)
	tmp = 0.0
	if (Float64(Float64(Float64(Float64(beta - alpha) / Float64(Float64(alpha + beta) + 2.0)) + 1.0) / 2.0) <= 0.6)
		tmp = 0.5;
	else
		tmp = 1.0;
	end
	return tmp
end
function tmp_2 = code(alpha, beta)
	tmp = 0.0;
	if (((((beta - alpha) / ((alpha + beta) + 2.0)) + 1.0) / 2.0) <= 0.6)
		tmp = 0.5;
	else
		tmp = 1.0;
	end
	tmp_2 = tmp;
end
code[alpha_, beta_] := If[LessEqual[N[(N[(N[(N[(beta - alpha), $MachinePrecision] / N[(N[(alpha + beta), $MachinePrecision] + 2.0), $MachinePrecision]), $MachinePrecision] + 1.0), $MachinePrecision] / 2.0), $MachinePrecision], 0.6], 0.5, 1.0]
\begin{array}{l}

\\
\begin{array}{l}
\mathbf{if}\;\frac{\frac{\beta - \alpha}{\left(\alpha + \beta\right) + 2} + 1}{2} \leq 0.6:\\
\;\;\;\;0.5\\

\mathbf{else}:\\
\;\;\;\;1\\


\end{array}
\end{array}
Derivation
  1. Split input into 2 regimes
  2. if (/.f64 (+.f64 (/.f64 (-.f64 beta alpha) (+.f64 (+.f64 alpha beta) #s(literal 2 binary64))) #s(literal 1 binary64)) #s(literal 2 binary64)) < 0.599999999999999978

    1. Initial program 64.9%

      \[\frac{\frac{\beta - \alpha}{\left(\alpha + \beta\right) + 2} + 1}{2} \]
    2. Taylor expanded in alpha around 0

      \[\leadsto \color{blue}{\frac{1}{2} \cdot \left(1 + \frac{\beta}{2 + \beta}\right)} \]
    3. Applied rewrites62.6%

      \[\leadsto \color{blue}{\left(\frac{\beta}{2 + \beta} + 1\right) \cdot 0.5} \]
    4. Taylor expanded in beta around 0

      \[\leadsto \frac{1}{2} \]
    5. Applied rewrites61.5%

      \[\leadsto 0.5 \]

    if 0.599999999999999978 < (/.f64 (+.f64 (/.f64 (-.f64 beta alpha) (+.f64 (+.f64 alpha beta) #s(literal 2 binary64))) #s(literal 1 binary64)) #s(literal 2 binary64))

    1. Initial program 100.0%

      \[\frac{\frac{\beta - \alpha}{\left(\alpha + \beta\right) + 2} + 1}{2} \]
    2. Taylor expanded in beta around inf

      \[\leadsto \color{blue}{1} \]
    3. Applied rewrites97.4%

      \[\leadsto \color{blue}{1} \]
  3. Recombined 2 regimes into one program.
  4. Add Preprocessing

Alternative 8: 99.9% accurate, 0.9× speedup?

\[\begin{array}{l} \\ \frac{\frac{\mathsf{fma}\left(4, \beta, 4\right)}{\left(\left(\alpha + \beta\right) + 2\right) \cdot 2}}{2} \end{array} \]
(FPCore (alpha beta)
 :precision binary64
 (/ (/ (fma 4.0 beta 4.0) (* (+ (+ alpha beta) 2.0) 2.0)) 2.0))
double code(double alpha, double beta) {
	return (fma(4.0, beta, 4.0) / (((alpha + beta) + 2.0) * 2.0)) / 2.0;
}
function code(alpha, beta)
	return Float64(Float64(fma(4.0, beta, 4.0) / Float64(Float64(Float64(alpha + beta) + 2.0) * 2.0)) / 2.0)
end
code[alpha_, beta_] := N[(N[(N[(4.0 * beta + 4.0), $MachinePrecision] / N[(N[(N[(alpha + beta), $MachinePrecision] + 2.0), $MachinePrecision] * 2.0), $MachinePrecision]), $MachinePrecision] / 2.0), $MachinePrecision]
\begin{array}{l}

\\
\frac{\frac{\mathsf{fma}\left(4, \beta, 4\right)}{\left(\left(\alpha + \beta\right) + 2\right) \cdot 2}}{2}
\end{array}
Derivation
  1. Initial program 74.5%

    \[\frac{\frac{\beta - \alpha}{\left(\alpha + \beta\right) + 2} + 1}{2} \]
  2. Applied rewrites74.7%

    \[\leadsto \frac{\color{blue}{\frac{\mathsf{fma}\left(\beta - \alpha, 2, \left(\left(\alpha + \beta\right) + 2\right) \cdot 2\right)}{\left(\left(\alpha + \beta\right) + 2\right) \cdot 2}}}{2} \]
  3. Taylor expanded in alpha around 0

    \[\leadsto \frac{\frac{\color{blue}{2 \cdot \beta + 2 \cdot \left(2 + \beta\right)}}{\left(\left(\alpha + \beta\right) + 2\right) \cdot 2}}{2} \]
  4. Applied rewrites99.9%

    \[\leadsto \frac{\frac{\color{blue}{\mathsf{fma}\left(2, \beta, 2 \cdot \left(2 + \beta\right)\right)}}{\left(\left(\alpha + \beta\right) + 2\right) \cdot 2}}{2} \]
  5. Taylor expanded in beta around 0

    \[\leadsto \frac{\frac{4 + \color{blue}{4 \cdot \beta}}{\left(\left(\alpha + \beta\right) + 2\right) \cdot 2}}{2} \]
  6. Applied rewrites99.9%

    \[\leadsto \frac{\frac{\mathsf{fma}\left(4, \color{blue}{\beta}, 4\right)}{\left(\left(\alpha + \beta\right) + 2\right) \cdot 2}}{2} \]
  7. Add Preprocessing

Alternative 9: 99.8% accurate, 1.0× speedup?

\[\begin{array}{l} \\ \frac{\mathsf{fma}\left(4, \beta, 4\right)}{\left(\left(\left(\alpha + \beta\right) + 2\right) \cdot 2\right) \cdot 2} \end{array} \]
(FPCore (alpha beta)
 :precision binary64
 (/ (fma 4.0 beta 4.0) (* (* (+ (+ alpha beta) 2.0) 2.0) 2.0)))
double code(double alpha, double beta) {
	return fma(4.0, beta, 4.0) / ((((alpha + beta) + 2.0) * 2.0) * 2.0);
}
function code(alpha, beta)
	return Float64(fma(4.0, beta, 4.0) / Float64(Float64(Float64(Float64(alpha + beta) + 2.0) * 2.0) * 2.0))
end
code[alpha_, beta_] := N[(N[(4.0 * beta + 4.0), $MachinePrecision] / N[(N[(N[(N[(alpha + beta), $MachinePrecision] + 2.0), $MachinePrecision] * 2.0), $MachinePrecision] * 2.0), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}

\\
\frac{\mathsf{fma}\left(4, \beta, 4\right)}{\left(\left(\left(\alpha + \beta\right) + 2\right) \cdot 2\right) \cdot 2}
\end{array}
Derivation
  1. Initial program 74.5%

    \[\frac{\frac{\beta - \alpha}{\left(\alpha + \beta\right) + 2} + 1}{2} \]
  2. Applied rewrites74.7%

    \[\leadsto \frac{\color{blue}{\frac{\mathsf{fma}\left(\beta - \alpha, 2, \left(\left(\alpha + \beta\right) + 2\right) \cdot 2\right)}{\left(\left(\alpha + \beta\right) + 2\right) \cdot 2}}}{2} \]
  3. Taylor expanded in alpha around 0

    \[\leadsto \frac{\frac{\color{blue}{2 \cdot \beta + 2 \cdot \left(2 + \beta\right)}}{\left(\left(\alpha + \beta\right) + 2\right) \cdot 2}}{2} \]
  4. Applied rewrites99.9%

    \[\leadsto \frac{\frac{\color{blue}{\mathsf{fma}\left(2, \beta, 2 \cdot \left(2 + \beta\right)\right)}}{\left(\left(\alpha + \beta\right) + 2\right) \cdot 2}}{2} \]
  5. Taylor expanded in beta around 0

    \[\leadsto \frac{\frac{4 + \color{blue}{4 \cdot \beta}}{\left(\left(\alpha + \beta\right) + 2\right) \cdot 2}}{2} \]
  6. Applied rewrites99.9%

    \[\leadsto \frac{\frac{\mathsf{fma}\left(4, \color{blue}{\beta}, 4\right)}{\left(\left(\alpha + \beta\right) + 2\right) \cdot 2}}{2} \]
  7. Applied rewrites99.8%

    \[\leadsto \color{blue}{\frac{\mathsf{fma}\left(4, \beta, 4\right)}{\left(\left(\left(\alpha + \beta\right) + 2\right) \cdot 2\right) \cdot 2}} \]
  8. Add Preprocessing

Alternative 10: 71.7% accurate, 2.7× speedup?

\[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;\beta \leq 2:\\ \;\;\;\;\mathsf{fma}\left(0.25, \beta, 0.5\right)\\ \mathbf{else}:\\ \;\;\;\;1\\ \end{array} \end{array} \]
(FPCore (alpha beta)
 :precision binary64
 (if (<= beta 2.0) (fma 0.25 beta 0.5) 1.0))
double code(double alpha, double beta) {
	double tmp;
	if (beta <= 2.0) {
		tmp = fma(0.25, beta, 0.5);
	} else {
		tmp = 1.0;
	}
	return tmp;
}
function code(alpha, beta)
	tmp = 0.0
	if (beta <= 2.0)
		tmp = fma(0.25, beta, 0.5);
	else
		tmp = 1.0;
	end
	return tmp
end
code[alpha_, beta_] := If[LessEqual[beta, 2.0], N[(0.25 * beta + 0.5), $MachinePrecision], 1.0]
\begin{array}{l}

\\
\begin{array}{l}
\mathbf{if}\;\beta \leq 2:\\
\;\;\;\;\mathsf{fma}\left(0.25, \beta, 0.5\right)\\

\mathbf{else}:\\
\;\;\;\;1\\


\end{array}
\end{array}
Derivation
  1. Split input into 2 regimes
  2. if beta < 2

    1. Initial program 69.5%

      \[\frac{\frac{\beta - \alpha}{\left(\alpha + \beta\right) + 2} + 1}{2} \]
    2. Taylor expanded in alpha around 0

      \[\leadsto \color{blue}{\frac{1}{2} \cdot \left(1 + \frac{\beta}{2 + \beta}\right)} \]
    3. Applied rewrites67.2%

      \[\leadsto \color{blue}{\left(\frac{\beta}{2 + \beta} + 1\right) \cdot 0.5} \]
    4. Taylor expanded in beta around 0

      \[\leadsto \frac{1}{2} \]
    5. Applied rewrites65.9%

      \[\leadsto 0.5 \]
    6. Taylor expanded in beta around 0

      \[\leadsto \frac{1}{2} + \color{blue}{\frac{1}{4} \cdot \beta} \]
    7. Applied rewrites66.6%

      \[\leadsto \mathsf{fma}\left(0.25, \color{blue}{\beta}, 0.5\right) \]

    if 2 < beta

    1. Initial program 84.7%

      \[\frac{\frac{\beta - \alpha}{\left(\alpha + \beta\right) + 2} + 1}{2} \]
    2. Taylor expanded in beta around inf

      \[\leadsto \color{blue}{1} \]
    3. Applied rewrites82.3%

      \[\leadsto \color{blue}{1} \]
  3. Recombined 2 regimes into one program.
  4. Add Preprocessing

Alternative 11: 36.5% accurate, 35.0× speedup?

\[\begin{array}{l} \\ 1 \end{array} \]
(FPCore (alpha beta) :precision binary64 1.0)
double code(double alpha, double beta) {
	return 1.0;
}
module fmin_fmax_functions
    implicit none
    private
    public fmax
    public fmin

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

real(8) function code(alpha, beta)
use fmin_fmax_functions
    real(8), intent (in) :: alpha
    real(8), intent (in) :: beta
    code = 1.0d0
end function
public static double code(double alpha, double beta) {
	return 1.0;
}
def code(alpha, beta):
	return 1.0
function code(alpha, beta)
	return 1.0
end
function tmp = code(alpha, beta)
	tmp = 1.0;
end
code[alpha_, beta_] := 1.0
\begin{array}{l}

\\
1
\end{array}
Derivation
  1. Initial program 74.5%

    \[\frac{\frac{\beta - \alpha}{\left(\alpha + \beta\right) + 2} + 1}{2} \]
  2. Taylor expanded in beta around inf

    \[\leadsto \color{blue}{1} \]
  3. Applied rewrites36.5%

    \[\leadsto \color{blue}{1} \]
  4. Add Preprocessing

Reproduce

?
herbie shell --seed 2025101 
(FPCore (alpha beta)
  :name "Octave 3.8, jcobi/1"
  :precision binary64
  :pre (and (> alpha -1.0) (> beta -1.0))
  (/ (+ (/ (- beta alpha) (+ (+ alpha beta) 2.0)) 1.0) 2.0))