Octave 3.8, oct_fill_randg

Percentage Accurate: 99.7% → 99.8%
Time: 3.4s
Alternatives: 10
Speedup: 1.5×

Specification

?
\[\begin{array}{l} t_0 := a - \frac{1}{3}\\ t\_0 \cdot \left(1 + \frac{1}{\sqrt{9 \cdot t\_0}} \cdot rand\right) \end{array} \]
(FPCore (a rand)
 :precision binary64
 (let* ((t_0 (- a (/ 1.0 3.0))))
   (* t_0 (+ 1.0 (* (/ 1.0 (sqrt (* 9.0 t_0))) rand)))))
double code(double a, double rand) {
	double t_0 = a - (1.0 / 3.0);
	return t_0 * (1.0 + ((1.0 / sqrt((9.0 * t_0))) * rand));
}
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(a, rand)
use fmin_fmax_functions
    real(8), intent (in) :: a
    real(8), intent (in) :: rand
    real(8) :: t_0
    t_0 = a - (1.0d0 / 3.0d0)
    code = t_0 * (1.0d0 + ((1.0d0 / sqrt((9.0d0 * t_0))) * rand))
end function
public static double code(double a, double rand) {
	double t_0 = a - (1.0 / 3.0);
	return t_0 * (1.0 + ((1.0 / Math.sqrt((9.0 * t_0))) * rand));
}
def code(a, rand):
	t_0 = a - (1.0 / 3.0)
	return t_0 * (1.0 + ((1.0 / math.sqrt((9.0 * t_0))) * rand))
function code(a, rand)
	t_0 = Float64(a - Float64(1.0 / 3.0))
	return Float64(t_0 * Float64(1.0 + Float64(Float64(1.0 / sqrt(Float64(9.0 * t_0))) * rand)))
end
function tmp = code(a, rand)
	t_0 = a - (1.0 / 3.0);
	tmp = t_0 * (1.0 + ((1.0 / sqrt((9.0 * t_0))) * rand));
end
code[a_, rand_] := Block[{t$95$0 = N[(a - N[(1.0 / 3.0), $MachinePrecision]), $MachinePrecision]}, N[(t$95$0 * N[(1.0 + N[(N[(1.0 / N[Sqrt[N[(9.0 * t$95$0), $MachinePrecision]], $MachinePrecision]), $MachinePrecision] * rand), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]]
\begin{array}{l}
t_0 := a - \frac{1}{3}\\
t\_0 \cdot \left(1 + \frac{1}{\sqrt{9 \cdot t\_0}} \cdot rand\right)
\end{array}

Local Percentage Accuracy vs ?

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

Accuracy vs Speed?

Herbie found 10 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: 99.7% accurate, 1.0× speedup?

\[\begin{array}{l} t_0 := a - \frac{1}{3}\\ t\_0 \cdot \left(1 + \frac{1}{\sqrt{9 \cdot t\_0}} \cdot rand\right) \end{array} \]
(FPCore (a rand)
 :precision binary64
 (let* ((t_0 (- a (/ 1.0 3.0))))
   (* t_0 (+ 1.0 (* (/ 1.0 (sqrt (* 9.0 t_0))) rand)))))
double code(double a, double rand) {
	double t_0 = a - (1.0 / 3.0);
	return t_0 * (1.0 + ((1.0 / sqrt((9.0 * t_0))) * rand));
}
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(a, rand)
use fmin_fmax_functions
    real(8), intent (in) :: a
    real(8), intent (in) :: rand
    real(8) :: t_0
    t_0 = a - (1.0d0 / 3.0d0)
    code = t_0 * (1.0d0 + ((1.0d0 / sqrt((9.0d0 * t_0))) * rand))
end function
public static double code(double a, double rand) {
	double t_0 = a - (1.0 / 3.0);
	return t_0 * (1.0 + ((1.0 / Math.sqrt((9.0 * t_0))) * rand));
}
def code(a, rand):
	t_0 = a - (1.0 / 3.0)
	return t_0 * (1.0 + ((1.0 / math.sqrt((9.0 * t_0))) * rand))
function code(a, rand)
	t_0 = Float64(a - Float64(1.0 / 3.0))
	return Float64(t_0 * Float64(1.0 + Float64(Float64(1.0 / sqrt(Float64(9.0 * t_0))) * rand)))
end
function tmp = code(a, rand)
	t_0 = a - (1.0 / 3.0);
	tmp = t_0 * (1.0 + ((1.0 / sqrt((9.0 * t_0))) * rand));
end
code[a_, rand_] := Block[{t$95$0 = N[(a - N[(1.0 / 3.0), $MachinePrecision]), $MachinePrecision]}, N[(t$95$0 * N[(1.0 + N[(N[(1.0 / N[Sqrt[N[(9.0 * t$95$0), $MachinePrecision]], $MachinePrecision]), $MachinePrecision] * rand), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]]
\begin{array}{l}
t_0 := a - \frac{1}{3}\\
t\_0 \cdot \left(1 + \frac{1}{\sqrt{9 \cdot t\_0}} \cdot rand\right)
\end{array}

Alternative 1: 99.8% accurate, 1.4× speedup?

\[\mathsf{fma}\left(\frac{a - 0.3333333333333333}{\sqrt{\left(a - 0.3333333333333333\right) \cdot 9}}, rand, a - 0.3333333333333333\right) \]
(FPCore (a rand)
 :precision binary64
 (fma
  (/ (- a 0.3333333333333333) (sqrt (* (- a 0.3333333333333333) 9.0)))
  rand
  (- a 0.3333333333333333)))
double code(double a, double rand) {
	return fma(((a - 0.3333333333333333) / sqrt(((a - 0.3333333333333333) * 9.0))), rand, (a - 0.3333333333333333));
}
function code(a, rand)
	return fma(Float64(Float64(a - 0.3333333333333333) / sqrt(Float64(Float64(a - 0.3333333333333333) * 9.0))), rand, Float64(a - 0.3333333333333333))
end
code[a_, rand_] := N[(N[(N[(a - 0.3333333333333333), $MachinePrecision] / N[Sqrt[N[(N[(a - 0.3333333333333333), $MachinePrecision] * 9.0), $MachinePrecision]], $MachinePrecision]), $MachinePrecision] * rand + N[(a - 0.3333333333333333), $MachinePrecision]), $MachinePrecision]
\mathsf{fma}\left(\frac{a - 0.3333333333333333}{\sqrt{\left(a - 0.3333333333333333\right) \cdot 9}}, rand, a - 0.3333333333333333\right)
Derivation
  1. Initial program 99.7%

    \[\left(a - \frac{1}{3}\right) \cdot \left(1 + \frac{1}{\sqrt{9 \cdot \left(a - \frac{1}{3}\right)}} \cdot rand\right) \]
  2. Step-by-step derivation
    1. lift-*.f64N/A

      \[\leadsto \color{blue}{\left(a - \frac{1}{3}\right) \cdot \left(1 + \frac{1}{\sqrt{9 \cdot \left(a - \frac{1}{3}\right)}} \cdot rand\right)} \]
    2. lift-+.f64N/A

      \[\leadsto \left(a - \frac{1}{3}\right) \cdot \color{blue}{\left(1 + \frac{1}{\sqrt{9 \cdot \left(a - \frac{1}{3}\right)}} \cdot rand\right)} \]
    3. +-commutativeN/A

      \[\leadsto \left(a - \frac{1}{3}\right) \cdot \color{blue}{\left(\frac{1}{\sqrt{9 \cdot \left(a - \frac{1}{3}\right)}} \cdot rand + 1\right)} \]
    4. distribute-lft-inN/A

      \[\leadsto \color{blue}{\left(a - \frac{1}{3}\right) \cdot \left(\frac{1}{\sqrt{9 \cdot \left(a - \frac{1}{3}\right)}} \cdot rand\right) + \left(a - \frac{1}{3}\right) \cdot 1} \]
    5. *-rgt-identityN/A

      \[\leadsto \left(a - \frac{1}{3}\right) \cdot \left(\frac{1}{\sqrt{9 \cdot \left(a - \frac{1}{3}\right)}} \cdot rand\right) + \color{blue}{\left(a - \frac{1}{3}\right)} \]
    6. lift-*.f64N/A

      \[\leadsto \left(a - \frac{1}{3}\right) \cdot \color{blue}{\left(\frac{1}{\sqrt{9 \cdot \left(a - \frac{1}{3}\right)}} \cdot rand\right)} + \left(a - \frac{1}{3}\right) \]
    7. associate-*r*N/A

      \[\leadsto \color{blue}{\left(\left(a - \frac{1}{3}\right) \cdot \frac{1}{\sqrt{9 \cdot \left(a - \frac{1}{3}\right)}}\right) \cdot rand} + \left(a - \frac{1}{3}\right) \]
    8. lower-fma.f64N/A

      \[\leadsto \color{blue}{\mathsf{fma}\left(\left(a - \frac{1}{3}\right) \cdot \frac{1}{\sqrt{9 \cdot \left(a - \frac{1}{3}\right)}}, rand, a - \frac{1}{3}\right)} \]
  3. Applied rewrites99.8%

    \[\leadsto \color{blue}{\mathsf{fma}\left(\frac{a - 0.3333333333333333}{\sqrt{\mathsf{fma}\left(9, a, -3\right)}}, rand, a - 0.3333333333333333\right)} \]
  4. Step-by-step derivation
    1. lift-fma.f64N/A

      \[\leadsto \mathsf{fma}\left(\frac{a - \frac{1}{3}}{\sqrt{\color{blue}{9 \cdot a + -3}}}, rand, a - \frac{1}{3}\right) \]
    2. metadata-evalN/A

      \[\leadsto \mathsf{fma}\left(\frac{a - \frac{1}{3}}{\sqrt{9 \cdot a + \color{blue}{9 \cdot \frac{-1}{3}}}}, rand, a - \frac{1}{3}\right) \]
    3. metadata-evalN/A

      \[\leadsto \mathsf{fma}\left(\frac{a - \frac{1}{3}}{\sqrt{9 \cdot a + 9 \cdot \color{blue}{\left(\mathsf{neg}\left(\frac{1}{3}\right)\right)}}}, rand, a - \frac{1}{3}\right) \]
    4. distribute-lft-inN/A

      \[\leadsto \mathsf{fma}\left(\frac{a - \frac{1}{3}}{\sqrt{\color{blue}{9 \cdot \left(a + \left(\mathsf{neg}\left(\frac{1}{3}\right)\right)\right)}}}, rand, a - \frac{1}{3}\right) \]
    5. sub-flipN/A

      \[\leadsto \mathsf{fma}\left(\frac{a - \frac{1}{3}}{\sqrt{9 \cdot \color{blue}{\left(a - \frac{1}{3}\right)}}}, rand, a - \frac{1}{3}\right) \]
    6. lift--.f64N/A

      \[\leadsto \mathsf{fma}\left(\frac{a - \frac{1}{3}}{\sqrt{9 \cdot \color{blue}{\left(a - \frac{1}{3}\right)}}}, rand, a - \frac{1}{3}\right) \]
    7. *-commutativeN/A

      \[\leadsto \mathsf{fma}\left(\frac{a - \frac{1}{3}}{\sqrt{\color{blue}{\left(a - \frac{1}{3}\right) \cdot 9}}}, rand, a - \frac{1}{3}\right) \]
    8. lower-*.f6499.8%

      \[\leadsto \mathsf{fma}\left(\frac{a - 0.3333333333333333}{\sqrt{\color{blue}{\left(a - 0.3333333333333333\right) \cdot 9}}}, rand, a - 0.3333333333333333\right) \]
  5. Applied rewrites99.8%

    \[\leadsto \mathsf{fma}\left(\frac{a - 0.3333333333333333}{\sqrt{\color{blue}{\left(a - 0.3333333333333333\right) \cdot 9}}}, rand, a - 0.3333333333333333\right) \]
  6. Add Preprocessing

Alternative 2: 99.8% accurate, 1.4× speedup?

\[\mathsf{fma}\left(\frac{a - 0.3333333333333333}{\sqrt{\mathsf{fma}\left(9, a, -3\right)}}, rand, a - 0.3333333333333333\right) \]
(FPCore (a rand)
 :precision binary64
 (fma
  (/ (- a 0.3333333333333333) (sqrt (fma 9.0 a -3.0)))
  rand
  (- a 0.3333333333333333)))
double code(double a, double rand) {
	return fma(((a - 0.3333333333333333) / sqrt(fma(9.0, a, -3.0))), rand, (a - 0.3333333333333333));
}
function code(a, rand)
	return fma(Float64(Float64(a - 0.3333333333333333) / sqrt(fma(9.0, a, -3.0))), rand, Float64(a - 0.3333333333333333))
end
code[a_, rand_] := N[(N[(N[(a - 0.3333333333333333), $MachinePrecision] / N[Sqrt[N[(9.0 * a + -3.0), $MachinePrecision]], $MachinePrecision]), $MachinePrecision] * rand + N[(a - 0.3333333333333333), $MachinePrecision]), $MachinePrecision]
\mathsf{fma}\left(\frac{a - 0.3333333333333333}{\sqrt{\mathsf{fma}\left(9, a, -3\right)}}, rand, a - 0.3333333333333333\right)
Derivation
  1. Initial program 99.7%

    \[\left(a - \frac{1}{3}\right) \cdot \left(1 + \frac{1}{\sqrt{9 \cdot \left(a - \frac{1}{3}\right)}} \cdot rand\right) \]
  2. Step-by-step derivation
    1. lift-*.f64N/A

      \[\leadsto \color{blue}{\left(a - \frac{1}{3}\right) \cdot \left(1 + \frac{1}{\sqrt{9 \cdot \left(a - \frac{1}{3}\right)}} \cdot rand\right)} \]
    2. lift-+.f64N/A

      \[\leadsto \left(a - \frac{1}{3}\right) \cdot \color{blue}{\left(1 + \frac{1}{\sqrt{9 \cdot \left(a - \frac{1}{3}\right)}} \cdot rand\right)} \]
    3. +-commutativeN/A

      \[\leadsto \left(a - \frac{1}{3}\right) \cdot \color{blue}{\left(\frac{1}{\sqrt{9 \cdot \left(a - \frac{1}{3}\right)}} \cdot rand + 1\right)} \]
    4. distribute-lft-inN/A

      \[\leadsto \color{blue}{\left(a - \frac{1}{3}\right) \cdot \left(\frac{1}{\sqrt{9 \cdot \left(a - \frac{1}{3}\right)}} \cdot rand\right) + \left(a - \frac{1}{3}\right) \cdot 1} \]
    5. *-rgt-identityN/A

      \[\leadsto \left(a - \frac{1}{3}\right) \cdot \left(\frac{1}{\sqrt{9 \cdot \left(a - \frac{1}{3}\right)}} \cdot rand\right) + \color{blue}{\left(a - \frac{1}{3}\right)} \]
    6. lift-*.f64N/A

      \[\leadsto \left(a - \frac{1}{3}\right) \cdot \color{blue}{\left(\frac{1}{\sqrt{9 \cdot \left(a - \frac{1}{3}\right)}} \cdot rand\right)} + \left(a - \frac{1}{3}\right) \]
    7. associate-*r*N/A

      \[\leadsto \color{blue}{\left(\left(a - \frac{1}{3}\right) \cdot \frac{1}{\sqrt{9 \cdot \left(a - \frac{1}{3}\right)}}\right) \cdot rand} + \left(a - \frac{1}{3}\right) \]
    8. lower-fma.f64N/A

      \[\leadsto \color{blue}{\mathsf{fma}\left(\left(a - \frac{1}{3}\right) \cdot \frac{1}{\sqrt{9 \cdot \left(a - \frac{1}{3}\right)}}, rand, a - \frac{1}{3}\right)} \]
  3. Applied rewrites99.8%

    \[\leadsto \color{blue}{\mathsf{fma}\left(\frac{a - 0.3333333333333333}{\sqrt{\mathsf{fma}\left(9, a, -3\right)}}, rand, a - 0.3333333333333333\right)} \]
  4. Add Preprocessing

Alternative 3: 99.8% accurate, 1.5× speedup?

\[\left(\frac{rand}{\sqrt{\mathsf{fma}\left(9, a, -3\right)}} - -1\right) \cdot \left(a - 0.3333333333333333\right) \]
(FPCore (a rand)
 :precision binary64
 (* (- (/ rand (sqrt (fma 9.0 a -3.0))) -1.0) (- a 0.3333333333333333)))
double code(double a, double rand) {
	return ((rand / sqrt(fma(9.0, a, -3.0))) - -1.0) * (a - 0.3333333333333333);
}
function code(a, rand)
	return Float64(Float64(Float64(rand / sqrt(fma(9.0, a, -3.0))) - -1.0) * Float64(a - 0.3333333333333333))
end
code[a_, rand_] := N[(N[(N[(rand / N[Sqrt[N[(9.0 * a + -3.0), $MachinePrecision]], $MachinePrecision]), $MachinePrecision] - -1.0), $MachinePrecision] * N[(a - 0.3333333333333333), $MachinePrecision]), $MachinePrecision]
\left(\frac{rand}{\sqrt{\mathsf{fma}\left(9, a, -3\right)}} - -1\right) \cdot \left(a - 0.3333333333333333\right)
Derivation
  1. Initial program 99.7%

    \[\left(a - \frac{1}{3}\right) \cdot \left(1 + \frac{1}{\sqrt{9 \cdot \left(a - \frac{1}{3}\right)}} \cdot rand\right) \]
  2. Step-by-step derivation
    1. lift-*.f64N/A

      \[\leadsto \color{blue}{\left(a - \frac{1}{3}\right) \cdot \left(1 + \frac{1}{\sqrt{9 \cdot \left(a - \frac{1}{3}\right)}} \cdot rand\right)} \]
    2. *-commutativeN/A

      \[\leadsto \color{blue}{\left(1 + \frac{1}{\sqrt{9 \cdot \left(a - \frac{1}{3}\right)}} \cdot rand\right) \cdot \left(a - \frac{1}{3}\right)} \]
    3. lower-*.f6499.7%

      \[\leadsto \color{blue}{\left(1 + \frac{1}{\sqrt{9 \cdot \left(a - \frac{1}{3}\right)}} \cdot rand\right) \cdot \left(a - \frac{1}{3}\right)} \]
  3. Applied rewrites99.8%

    \[\leadsto \color{blue}{\left(\frac{rand}{\sqrt{\mathsf{fma}\left(9, a, -3\right)}} - -1\right) \cdot \left(a - 0.3333333333333333\right)} \]
  4. Add Preprocessing

Alternative 4: 98.9% accurate, 1.5× speedup?

\[\begin{array}{l} \mathbf{if}\;a \leq 3300000:\\ \;\;\;\;\frac{rand}{\sqrt{\mathsf{fma}\left(9, a, -3\right)}} \cdot \left(a - 0.3333333333333333\right)\\ \mathbf{else}:\\ \;\;\;\;\mathsf{fma}\left(0.1111111111111111 \cdot \sqrt{9 \cdot a}, rand, a\right)\\ \end{array} \]
(FPCore (a rand)
 :precision binary64
 (if (<= a 3300000.0)
   (* (/ rand (sqrt (fma 9.0 a -3.0))) (- a 0.3333333333333333))
   (fma (* 0.1111111111111111 (sqrt (* 9.0 a))) rand a)))
double code(double a, double rand) {
	double tmp;
	if (a <= 3300000.0) {
		tmp = (rand / sqrt(fma(9.0, a, -3.0))) * (a - 0.3333333333333333);
	} else {
		tmp = fma((0.1111111111111111 * sqrt((9.0 * a))), rand, a);
	}
	return tmp;
}
function code(a, rand)
	tmp = 0.0
	if (a <= 3300000.0)
		tmp = Float64(Float64(rand / sqrt(fma(9.0, a, -3.0))) * Float64(a - 0.3333333333333333));
	else
		tmp = fma(Float64(0.1111111111111111 * sqrt(Float64(9.0 * a))), rand, a);
	end
	return tmp
end
code[a_, rand_] := If[LessEqual[a, 3300000.0], N[(N[(rand / N[Sqrt[N[(9.0 * a + -3.0), $MachinePrecision]], $MachinePrecision]), $MachinePrecision] * N[(a - 0.3333333333333333), $MachinePrecision]), $MachinePrecision], N[(N[(0.1111111111111111 * N[Sqrt[N[(9.0 * a), $MachinePrecision]], $MachinePrecision]), $MachinePrecision] * rand + a), $MachinePrecision]]
\begin{array}{l}
\mathbf{if}\;a \leq 3300000:\\
\;\;\;\;\frac{rand}{\sqrt{\mathsf{fma}\left(9, a, -3\right)}} \cdot \left(a - 0.3333333333333333\right)\\

\mathbf{else}:\\
\;\;\;\;\mathsf{fma}\left(0.1111111111111111 \cdot \sqrt{9 \cdot a}, rand, a\right)\\


\end{array}
Derivation
  1. Split input into 2 regimes
  2. if a < 3.3e6

    1. Initial program 99.7%

      \[\left(a - \frac{1}{3}\right) \cdot \left(1 + \frac{1}{\sqrt{9 \cdot \left(a - \frac{1}{3}\right)}} \cdot rand\right) \]
    2. Taylor expanded in rand around inf

      \[\leadsto \color{blue}{\frac{rand \cdot \left(a - \frac{1}{3}\right)}{\sqrt{9 \cdot \left(a - \frac{1}{3}\right)}}} \]
    3. Step-by-step derivation
      1. metadata-evalN/A

        \[\leadsto \frac{rand \cdot \left(a - \frac{1}{3}\right)}{\sqrt{9 \cdot \left(a - \color{blue}{\frac{1}{3}}\right)}} \]
      2. metadata-evalN/A

        \[\leadsto \frac{rand \cdot \left(a - \frac{1}{3}\right)}{\sqrt{9 \cdot \left(a - \frac{1}{3}\right)}} \]
      3. lower-/.f64N/A

        \[\leadsto \frac{rand \cdot \left(a - \frac{1}{3}\right)}{\color{blue}{\sqrt{9 \cdot \left(a - \frac{1}{3}\right)}}} \]
      4. lower-*.f64N/A

        \[\leadsto \frac{rand \cdot \left(a - \frac{1}{3}\right)}{\sqrt{\color{blue}{9 \cdot \left(a - \frac{1}{3}\right)}}} \]
      5. lower--.f64N/A

        \[\leadsto \frac{rand \cdot \left(a - \frac{1}{3}\right)}{\sqrt{9 \cdot \color{blue}{\left(a - \frac{1}{3}\right)}}} \]
      6. metadata-evalN/A

        \[\leadsto \frac{rand \cdot \left(a - \frac{1}{3}\right)}{\sqrt{9 \cdot \left(a - \color{blue}{\frac{1}{3}}\right)}} \]
      7. lower-sqrt.f64N/A

        \[\leadsto \frac{rand \cdot \left(a - \frac{1}{3}\right)}{\sqrt{9 \cdot \left(a - \frac{1}{3}\right)}} \]
      8. lower-*.f64N/A

        \[\leadsto \frac{rand \cdot \left(a - \frac{1}{3}\right)}{\sqrt{9 \cdot \left(a - \frac{1}{3}\right)}} \]
      9. lower--.f64N/A

        \[\leadsto \frac{rand \cdot \left(a - \frac{1}{3}\right)}{\sqrt{9 \cdot \left(a - \frac{1}{3}\right)}} \]
      10. metadata-eval30.3%

        \[\leadsto \frac{rand \cdot \left(a - 0.3333333333333333\right)}{\sqrt{9 \cdot \left(a - 0.3333333333333333\right)}} \]
    4. Applied rewrites30.3%

      \[\leadsto \color{blue}{\frac{rand \cdot \left(a - 0.3333333333333333\right)}{\sqrt{9 \cdot \left(a - 0.3333333333333333\right)}}} \]
    5. Step-by-step derivation
      1. lift-/.f64N/A

        \[\leadsto \frac{rand \cdot \left(a - \frac{1}{3}\right)}{\color{blue}{\sqrt{9 \cdot \left(a - \frac{1}{3}\right)}}} \]
      2. lift-*.f64N/A

        \[\leadsto \frac{rand \cdot \left(a - \frac{1}{3}\right)}{\sqrt{\color{blue}{9 \cdot \left(a - \frac{1}{3}\right)}}} \]
      3. associate-*l/N/A

        \[\leadsto \frac{rand}{\sqrt{9 \cdot \left(a - \frac{1}{3}\right)}} \cdot \color{blue}{\left(a - \frac{1}{3}\right)} \]
      4. mult-flip-revN/A

        \[\leadsto \left(rand \cdot \frac{1}{\sqrt{9 \cdot \left(a - \frac{1}{3}\right)}}\right) \cdot \left(\color{blue}{a} - \frac{1}{3}\right) \]
      5. lift-sqrt.f64N/A

        \[\leadsto \left(rand \cdot \frac{1}{\sqrt{9 \cdot \left(a - \frac{1}{3}\right)}}\right) \cdot \left(a - \frac{1}{3}\right) \]
      6. lift-*.f64N/A

        \[\leadsto \left(rand \cdot \frac{1}{\sqrt{9 \cdot \left(a - \frac{1}{3}\right)}}\right) \cdot \left(a - \frac{1}{3}\right) \]
      7. lift--.f64N/A

        \[\leadsto \left(rand \cdot \frac{1}{\sqrt{9 \cdot \left(a - \frac{1}{3}\right)}}\right) \cdot \left(a - \frac{1}{3}\right) \]
      8. *-commutativeN/A

        \[\leadsto \left(\frac{1}{\sqrt{9 \cdot \left(a - \frac{1}{3}\right)}} \cdot rand\right) \cdot \left(\color{blue}{a} - \frac{1}{3}\right) \]
      9. lower-*.f64N/A

        \[\leadsto \left(\frac{1}{\sqrt{9 \cdot \left(a - \frac{1}{3}\right)}} \cdot rand\right) \cdot \color{blue}{\left(a - \frac{1}{3}\right)} \]
    6. Applied rewrites37.1%

      \[\leadsto \frac{rand}{\sqrt{\mathsf{fma}\left(9, a, -3\right)}} \cdot \color{blue}{\left(a - 0.3333333333333333\right)} \]

    if 3.3e6 < a

    1. Initial program 99.7%

      \[\left(a - \frac{1}{3}\right) \cdot \left(1 + \frac{1}{\sqrt{9 \cdot \left(a - \frac{1}{3}\right)}} \cdot rand\right) \]
    2. Applied rewrites99.4%

      \[\leadsto \left(a - \frac{1}{3}\right) \cdot \color{blue}{\frac{\mathsf{fma}\left(-9, 0.3333333333333333 - a, \sqrt{\mathsf{fma}\left(9, a, -3\right)} \cdot rand\right)}{\mathsf{fma}\left(9, a, -3\right)}} \]
    3. Taylor expanded in a around inf

      \[\leadsto \color{blue}{\frac{1}{9} \cdot \left(a \cdot \left(9 + rand \cdot \sqrt{\frac{9}{a}}\right)\right)} \]
    4. Step-by-step derivation
      1. lower-*.f64N/A

        \[\leadsto \frac{1}{9} \cdot \color{blue}{\left(a \cdot \left(9 + rand \cdot \sqrt{\frac{9}{a}}\right)\right)} \]
      2. lower-*.f64N/A

        \[\leadsto \frac{1}{9} \cdot \left(a \cdot \color{blue}{\left(9 + rand \cdot \sqrt{\frac{9}{a}}\right)}\right) \]
      3. lower-+.f64N/A

        \[\leadsto \frac{1}{9} \cdot \left(a \cdot \left(9 + \color{blue}{rand \cdot \sqrt{\frac{9}{a}}}\right)\right) \]
      4. lower-*.f64N/A

        \[\leadsto \frac{1}{9} \cdot \left(a \cdot \left(9 + rand \cdot \color{blue}{\sqrt{\frac{9}{a}}}\right)\right) \]
      5. lower-sqrt.f64N/A

        \[\leadsto \frac{1}{9} \cdot \left(a \cdot \left(9 + rand \cdot \sqrt{\frac{9}{a}}\right)\right) \]
      6. lower-/.f6497.3%

        \[\leadsto 0.1111111111111111 \cdot \left(a \cdot \left(9 + rand \cdot \sqrt{\frac{9}{a}}\right)\right) \]
    5. Applied rewrites97.3%

      \[\leadsto \color{blue}{0.1111111111111111 \cdot \left(a \cdot \left(9 + rand \cdot \sqrt{\frac{9}{a}}\right)\right)} \]
    6. Taylor expanded in a around 0

      \[\leadsto a + \color{blue}{\frac{1}{9} \cdot \left(rand \cdot \sqrt{9 \cdot a}\right)} \]
    7. Step-by-step derivation
      1. lower-+.f64N/A

        \[\leadsto a + \frac{1}{9} \cdot \color{blue}{\left(rand \cdot \sqrt{9 \cdot a}\right)} \]
      2. lower-*.f64N/A

        \[\leadsto a + \frac{1}{9} \cdot \left(rand \cdot \color{blue}{\sqrt{9 \cdot a}}\right) \]
      3. lower-*.f64N/A

        \[\leadsto a + \frac{1}{9} \cdot \left(rand \cdot \sqrt{9 \cdot a}\right) \]
      4. lower-sqrt.f64N/A

        \[\leadsto a + \frac{1}{9} \cdot \left(rand \cdot \sqrt{9 \cdot a}\right) \]
      5. lower-*.f6497.7%

        \[\leadsto a + 0.1111111111111111 \cdot \left(rand \cdot \sqrt{9 \cdot a}\right) \]
    8. Applied rewrites97.7%

      \[\leadsto a + \color{blue}{0.1111111111111111 \cdot \left(rand \cdot \sqrt{9 \cdot a}\right)} \]
    9. Step-by-step derivation
      1. lift-+.f64N/A

        \[\leadsto a + \frac{1}{9} \cdot \color{blue}{\left(rand \cdot \sqrt{9 \cdot a}\right)} \]
      2. +-commutativeN/A

        \[\leadsto \frac{1}{9} \cdot \left(rand \cdot \sqrt{9 \cdot a}\right) + a \]
      3. lift-*.f64N/A

        \[\leadsto \frac{1}{9} \cdot \left(rand \cdot \sqrt{9 \cdot a}\right) + a \]
      4. lift-*.f64N/A

        \[\leadsto \frac{1}{9} \cdot \left(rand \cdot \sqrt{9 \cdot a}\right) + a \]
      5. *-commutativeN/A

        \[\leadsto \frac{1}{9} \cdot \left(\sqrt{9 \cdot a} \cdot rand\right) + a \]
      6. associate-*r*N/A

        \[\leadsto \left(\frac{1}{9} \cdot \sqrt{9 \cdot a}\right) \cdot rand + a \]
      7. lower-fma.f64N/A

        \[\leadsto \mathsf{fma}\left(\frac{1}{9} \cdot \sqrt{9 \cdot a}, rand, a\right) \]
      8. lower-*.f6497.7%

        \[\leadsto \mathsf{fma}\left(0.1111111111111111 \cdot \sqrt{9 \cdot a}, rand, a\right) \]
    10. Applied rewrites97.7%

      \[\leadsto \mathsf{fma}\left(0.1111111111111111 \cdot \sqrt{9 \cdot a}, rand, a\right) \]
  3. Recombined 2 regimes into one program.
  4. Add Preprocessing

Alternative 5: 98.8% accurate, 1.7× speedup?

\[\mathsf{fma}\left(\frac{1}{\sqrt{\frac{9}{a}}}, rand, a - 0.3333333333333333\right) \]
(FPCore (a rand)
 :precision binary64
 (fma (/ 1.0 (sqrt (/ 9.0 a))) rand (- a 0.3333333333333333)))
double code(double a, double rand) {
	return fma((1.0 / sqrt((9.0 / a))), rand, (a - 0.3333333333333333));
}
function code(a, rand)
	return fma(Float64(1.0 / sqrt(Float64(9.0 / a))), rand, Float64(a - 0.3333333333333333))
end
code[a_, rand_] := N[(N[(1.0 / N[Sqrt[N[(9.0 / a), $MachinePrecision]], $MachinePrecision]), $MachinePrecision] * rand + N[(a - 0.3333333333333333), $MachinePrecision]), $MachinePrecision]
\mathsf{fma}\left(\frac{1}{\sqrt{\frac{9}{a}}}, rand, a - 0.3333333333333333\right)
Derivation
  1. Initial program 99.7%

    \[\left(a - \frac{1}{3}\right) \cdot \left(1 + \frac{1}{\sqrt{9 \cdot \left(a - \frac{1}{3}\right)}} \cdot rand\right) \]
  2. Step-by-step derivation
    1. lift-*.f64N/A

      \[\leadsto \color{blue}{\left(a - \frac{1}{3}\right) \cdot \left(1 + \frac{1}{\sqrt{9 \cdot \left(a - \frac{1}{3}\right)}} \cdot rand\right)} \]
    2. lift-+.f64N/A

      \[\leadsto \left(a - \frac{1}{3}\right) \cdot \color{blue}{\left(1 + \frac{1}{\sqrt{9 \cdot \left(a - \frac{1}{3}\right)}} \cdot rand\right)} \]
    3. +-commutativeN/A

      \[\leadsto \left(a - \frac{1}{3}\right) \cdot \color{blue}{\left(\frac{1}{\sqrt{9 \cdot \left(a - \frac{1}{3}\right)}} \cdot rand + 1\right)} \]
    4. distribute-lft-inN/A

      \[\leadsto \color{blue}{\left(a - \frac{1}{3}\right) \cdot \left(\frac{1}{\sqrt{9 \cdot \left(a - \frac{1}{3}\right)}} \cdot rand\right) + \left(a - \frac{1}{3}\right) \cdot 1} \]
    5. *-rgt-identityN/A

      \[\leadsto \left(a - \frac{1}{3}\right) \cdot \left(\frac{1}{\sqrt{9 \cdot \left(a - \frac{1}{3}\right)}} \cdot rand\right) + \color{blue}{\left(a - \frac{1}{3}\right)} \]
    6. lift-*.f64N/A

      \[\leadsto \left(a - \frac{1}{3}\right) \cdot \color{blue}{\left(\frac{1}{\sqrt{9 \cdot \left(a - \frac{1}{3}\right)}} \cdot rand\right)} + \left(a - \frac{1}{3}\right) \]
    7. associate-*r*N/A

      \[\leadsto \color{blue}{\left(\left(a - \frac{1}{3}\right) \cdot \frac{1}{\sqrt{9 \cdot \left(a - \frac{1}{3}\right)}}\right) \cdot rand} + \left(a - \frac{1}{3}\right) \]
    8. lower-fma.f64N/A

      \[\leadsto \color{blue}{\mathsf{fma}\left(\left(a - \frac{1}{3}\right) \cdot \frac{1}{\sqrt{9 \cdot \left(a - \frac{1}{3}\right)}}, rand, a - \frac{1}{3}\right)} \]
  3. Applied rewrites99.8%

    \[\leadsto \color{blue}{\mathsf{fma}\left(\frac{a - 0.3333333333333333}{\sqrt{\mathsf{fma}\left(9, a, -3\right)}}, rand, a - 0.3333333333333333\right)} \]
  4. Taylor expanded in a around inf

    \[\leadsto \mathsf{fma}\left(\color{blue}{\frac{1}{\sqrt{\frac{9}{a}}}}, rand, a - 0.3333333333333333\right) \]
  5. Step-by-step derivation
    1. lower-/.f64N/A

      \[\leadsto \mathsf{fma}\left(\frac{1}{\color{blue}{\sqrt{\frac{9}{a}}}}, rand, a - \frac{1}{3}\right) \]
    2. lower-sqrt.f64N/A

      \[\leadsto \mathsf{fma}\left(\frac{1}{\sqrt{\frac{9}{a}}}, rand, a - \frac{1}{3}\right) \]
    3. lower-/.f6498.9%

      \[\leadsto \mathsf{fma}\left(\frac{1}{\sqrt{\frac{9}{a}}}, rand, a - 0.3333333333333333\right) \]
  6. Applied rewrites98.9%

    \[\leadsto \mathsf{fma}\left(\color{blue}{\frac{1}{\sqrt{\frac{9}{a}}}}, rand, a - 0.3333333333333333\right) \]
  7. Add Preprocessing

Alternative 6: 98.0% accurate, 1.8× speedup?

\[\mathsf{fma}\left(\frac{a}{\sqrt{9 \cdot a}}, rand, a - 0.3333333333333333\right) \]
(FPCore (a rand)
 :precision binary64
 (fma (/ a (sqrt (* 9.0 a))) rand (- a 0.3333333333333333)))
double code(double a, double rand) {
	return fma((a / sqrt((9.0 * a))), rand, (a - 0.3333333333333333));
}
function code(a, rand)
	return fma(Float64(a / sqrt(Float64(9.0 * a))), rand, Float64(a - 0.3333333333333333))
end
code[a_, rand_] := N[(N[(a / N[Sqrt[N[(9.0 * a), $MachinePrecision]], $MachinePrecision]), $MachinePrecision] * rand + N[(a - 0.3333333333333333), $MachinePrecision]), $MachinePrecision]
\mathsf{fma}\left(\frac{a}{\sqrt{9 \cdot a}}, rand, a - 0.3333333333333333\right)
Derivation
  1. Initial program 99.7%

    \[\left(a - \frac{1}{3}\right) \cdot \left(1 + \frac{1}{\sqrt{9 \cdot \left(a - \frac{1}{3}\right)}} \cdot rand\right) \]
  2. Step-by-step derivation
    1. lift-*.f64N/A

      \[\leadsto \color{blue}{\left(a - \frac{1}{3}\right) \cdot \left(1 + \frac{1}{\sqrt{9 \cdot \left(a - \frac{1}{3}\right)}} \cdot rand\right)} \]
    2. lift-+.f64N/A

      \[\leadsto \left(a - \frac{1}{3}\right) \cdot \color{blue}{\left(1 + \frac{1}{\sqrt{9 \cdot \left(a - \frac{1}{3}\right)}} \cdot rand\right)} \]
    3. +-commutativeN/A

      \[\leadsto \left(a - \frac{1}{3}\right) \cdot \color{blue}{\left(\frac{1}{\sqrt{9 \cdot \left(a - \frac{1}{3}\right)}} \cdot rand + 1\right)} \]
    4. distribute-lft-inN/A

      \[\leadsto \color{blue}{\left(a - \frac{1}{3}\right) \cdot \left(\frac{1}{\sqrt{9 \cdot \left(a - \frac{1}{3}\right)}} \cdot rand\right) + \left(a - \frac{1}{3}\right) \cdot 1} \]
    5. *-rgt-identityN/A

      \[\leadsto \left(a - \frac{1}{3}\right) \cdot \left(\frac{1}{\sqrt{9 \cdot \left(a - \frac{1}{3}\right)}} \cdot rand\right) + \color{blue}{\left(a - \frac{1}{3}\right)} \]
    6. lift-*.f64N/A

      \[\leadsto \left(a - \frac{1}{3}\right) \cdot \color{blue}{\left(\frac{1}{\sqrt{9 \cdot \left(a - \frac{1}{3}\right)}} \cdot rand\right)} + \left(a - \frac{1}{3}\right) \]
    7. associate-*r*N/A

      \[\leadsto \color{blue}{\left(\left(a - \frac{1}{3}\right) \cdot \frac{1}{\sqrt{9 \cdot \left(a - \frac{1}{3}\right)}}\right) \cdot rand} + \left(a - \frac{1}{3}\right) \]
    8. lower-fma.f64N/A

      \[\leadsto \color{blue}{\mathsf{fma}\left(\left(a - \frac{1}{3}\right) \cdot \frac{1}{\sqrt{9 \cdot \left(a - \frac{1}{3}\right)}}, rand, a - \frac{1}{3}\right)} \]
  3. Applied rewrites99.8%

    \[\leadsto \color{blue}{\mathsf{fma}\left(\frac{a - 0.3333333333333333}{\sqrt{\mathsf{fma}\left(9, a, -3\right)}}, rand, a - 0.3333333333333333\right)} \]
  4. Taylor expanded in a around inf

    \[\leadsto \mathsf{fma}\left(\color{blue}{\frac{1}{\sqrt{\frac{9}{a}}}}, rand, a - 0.3333333333333333\right) \]
  5. Step-by-step derivation
    1. lower-/.f64N/A

      \[\leadsto \mathsf{fma}\left(\frac{1}{\color{blue}{\sqrt{\frac{9}{a}}}}, rand, a - \frac{1}{3}\right) \]
    2. lower-sqrt.f64N/A

      \[\leadsto \mathsf{fma}\left(\frac{1}{\sqrt{\frac{9}{a}}}, rand, a - \frac{1}{3}\right) \]
    3. lower-/.f6498.9%

      \[\leadsto \mathsf{fma}\left(\frac{1}{\sqrt{\frac{9}{a}}}, rand, a - 0.3333333333333333\right) \]
  6. Applied rewrites98.9%

    \[\leadsto \mathsf{fma}\left(\color{blue}{\frac{1}{\sqrt{\frac{9}{a}}}}, rand, a - 0.3333333333333333\right) \]
  7. Taylor expanded in a around 0

    \[\leadsto \mathsf{fma}\left(\frac{a}{\color{blue}{\sqrt{9 \cdot a}}}, rand, a - 0.3333333333333333\right) \]
  8. Step-by-step derivation
    1. lower-/.f64N/A

      \[\leadsto \mathsf{fma}\left(\frac{a}{\sqrt{9 \cdot a}}, rand, a - \frac{1}{3}\right) \]
    2. lower-sqrt.f64N/A

      \[\leadsto \mathsf{fma}\left(\frac{a}{\sqrt{9 \cdot a}}, rand, a - \frac{1}{3}\right) \]
    3. lower-*.f6498.8%

      \[\leadsto \mathsf{fma}\left(\frac{a}{\sqrt{9 \cdot a}}, rand, a - 0.3333333333333333\right) \]
  9. Applied rewrites98.8%

    \[\leadsto \mathsf{fma}\left(\frac{a}{\color{blue}{\sqrt{9 \cdot a}}}, rand, a - 0.3333333333333333\right) \]
  10. Add Preprocessing

Alternative 7: 97.7% accurate, 2.2× speedup?

\[\mathsf{fma}\left(0.1111111111111111 \cdot \sqrt{9 \cdot a}, rand, a\right) \]
(FPCore (a rand)
 :precision binary64
 (fma (* 0.1111111111111111 (sqrt (* 9.0 a))) rand a))
double code(double a, double rand) {
	return fma((0.1111111111111111 * sqrt((9.0 * a))), rand, a);
}
function code(a, rand)
	return fma(Float64(0.1111111111111111 * sqrt(Float64(9.0 * a))), rand, a)
end
code[a_, rand_] := N[(N[(0.1111111111111111 * N[Sqrt[N[(9.0 * a), $MachinePrecision]], $MachinePrecision]), $MachinePrecision] * rand + a), $MachinePrecision]
\mathsf{fma}\left(0.1111111111111111 \cdot \sqrt{9 \cdot a}, rand, a\right)
Derivation
  1. Initial program 99.7%

    \[\left(a - \frac{1}{3}\right) \cdot \left(1 + \frac{1}{\sqrt{9 \cdot \left(a - \frac{1}{3}\right)}} \cdot rand\right) \]
  2. Applied rewrites99.4%

    \[\leadsto \left(a - \frac{1}{3}\right) \cdot \color{blue}{\frac{\mathsf{fma}\left(-9, 0.3333333333333333 - a, \sqrt{\mathsf{fma}\left(9, a, -3\right)} \cdot rand\right)}{\mathsf{fma}\left(9, a, -3\right)}} \]
  3. Taylor expanded in a around inf

    \[\leadsto \color{blue}{\frac{1}{9} \cdot \left(a \cdot \left(9 + rand \cdot \sqrt{\frac{9}{a}}\right)\right)} \]
  4. Step-by-step derivation
    1. lower-*.f64N/A

      \[\leadsto \frac{1}{9} \cdot \color{blue}{\left(a \cdot \left(9 + rand \cdot \sqrt{\frac{9}{a}}\right)\right)} \]
    2. lower-*.f64N/A

      \[\leadsto \frac{1}{9} \cdot \left(a \cdot \color{blue}{\left(9 + rand \cdot \sqrt{\frac{9}{a}}\right)}\right) \]
    3. lower-+.f64N/A

      \[\leadsto \frac{1}{9} \cdot \left(a \cdot \left(9 + \color{blue}{rand \cdot \sqrt{\frac{9}{a}}}\right)\right) \]
    4. lower-*.f64N/A

      \[\leadsto \frac{1}{9} \cdot \left(a \cdot \left(9 + rand \cdot \color{blue}{\sqrt{\frac{9}{a}}}\right)\right) \]
    5. lower-sqrt.f64N/A

      \[\leadsto \frac{1}{9} \cdot \left(a \cdot \left(9 + rand \cdot \sqrt{\frac{9}{a}}\right)\right) \]
    6. lower-/.f6497.3%

      \[\leadsto 0.1111111111111111 \cdot \left(a \cdot \left(9 + rand \cdot \sqrt{\frac{9}{a}}\right)\right) \]
  5. Applied rewrites97.3%

    \[\leadsto \color{blue}{0.1111111111111111 \cdot \left(a \cdot \left(9 + rand \cdot \sqrt{\frac{9}{a}}\right)\right)} \]
  6. Taylor expanded in a around 0

    \[\leadsto a + \color{blue}{\frac{1}{9} \cdot \left(rand \cdot \sqrt{9 \cdot a}\right)} \]
  7. Step-by-step derivation
    1. lower-+.f64N/A

      \[\leadsto a + \frac{1}{9} \cdot \color{blue}{\left(rand \cdot \sqrt{9 \cdot a}\right)} \]
    2. lower-*.f64N/A

      \[\leadsto a + \frac{1}{9} \cdot \left(rand \cdot \color{blue}{\sqrt{9 \cdot a}}\right) \]
    3. lower-*.f64N/A

      \[\leadsto a + \frac{1}{9} \cdot \left(rand \cdot \sqrt{9 \cdot a}\right) \]
    4. lower-sqrt.f64N/A

      \[\leadsto a + \frac{1}{9} \cdot \left(rand \cdot \sqrt{9 \cdot a}\right) \]
    5. lower-*.f6497.7%

      \[\leadsto a + 0.1111111111111111 \cdot \left(rand \cdot \sqrt{9 \cdot a}\right) \]
  8. Applied rewrites97.7%

    \[\leadsto a + \color{blue}{0.1111111111111111 \cdot \left(rand \cdot \sqrt{9 \cdot a}\right)} \]
  9. Step-by-step derivation
    1. lift-+.f64N/A

      \[\leadsto a + \frac{1}{9} \cdot \color{blue}{\left(rand \cdot \sqrt{9 \cdot a}\right)} \]
    2. +-commutativeN/A

      \[\leadsto \frac{1}{9} \cdot \left(rand \cdot \sqrt{9 \cdot a}\right) + a \]
    3. lift-*.f64N/A

      \[\leadsto \frac{1}{9} \cdot \left(rand \cdot \sqrt{9 \cdot a}\right) + a \]
    4. lift-*.f64N/A

      \[\leadsto \frac{1}{9} \cdot \left(rand \cdot \sqrt{9 \cdot a}\right) + a \]
    5. *-commutativeN/A

      \[\leadsto \frac{1}{9} \cdot \left(\sqrt{9 \cdot a} \cdot rand\right) + a \]
    6. associate-*r*N/A

      \[\leadsto \left(\frac{1}{9} \cdot \sqrt{9 \cdot a}\right) \cdot rand + a \]
    7. lower-fma.f64N/A

      \[\leadsto \mathsf{fma}\left(\frac{1}{9} \cdot \sqrt{9 \cdot a}, rand, a\right) \]
    8. lower-*.f6497.7%

      \[\leadsto \mathsf{fma}\left(0.1111111111111111 \cdot \sqrt{9 \cdot a}, rand, a\right) \]
  10. Applied rewrites97.7%

    \[\leadsto \mathsf{fma}\left(0.1111111111111111 \cdot \sqrt{9 \cdot a}, rand, a\right) \]
  11. Add Preprocessing

Alternative 8: 97.7% accurate, 2.2× speedup?

\[\mathsf{fma}\left(0.1111111111111111 \cdot rand, \sqrt{9 \cdot a}, a\right) \]
(FPCore (a rand)
 :precision binary64
 (fma (* 0.1111111111111111 rand) (sqrt (* 9.0 a)) a))
double code(double a, double rand) {
	return fma((0.1111111111111111 * rand), sqrt((9.0 * a)), a);
}
function code(a, rand)
	return fma(Float64(0.1111111111111111 * rand), sqrt(Float64(9.0 * a)), a)
end
code[a_, rand_] := N[(N[(0.1111111111111111 * rand), $MachinePrecision] * N[Sqrt[N[(9.0 * a), $MachinePrecision]], $MachinePrecision] + a), $MachinePrecision]
\mathsf{fma}\left(0.1111111111111111 \cdot rand, \sqrt{9 \cdot a}, a\right)
Derivation
  1. Initial program 99.7%

    \[\left(a - \frac{1}{3}\right) \cdot \left(1 + \frac{1}{\sqrt{9 \cdot \left(a - \frac{1}{3}\right)}} \cdot rand\right) \]
  2. Applied rewrites99.4%

    \[\leadsto \left(a - \frac{1}{3}\right) \cdot \color{blue}{\frac{\mathsf{fma}\left(-9, 0.3333333333333333 - a, \sqrt{\mathsf{fma}\left(9, a, -3\right)} \cdot rand\right)}{\mathsf{fma}\left(9, a, -3\right)}} \]
  3. Taylor expanded in a around inf

    \[\leadsto \color{blue}{\frac{1}{9} \cdot \left(a \cdot \left(9 + rand \cdot \sqrt{\frac{9}{a}}\right)\right)} \]
  4. Step-by-step derivation
    1. lower-*.f64N/A

      \[\leadsto \frac{1}{9} \cdot \color{blue}{\left(a \cdot \left(9 + rand \cdot \sqrt{\frac{9}{a}}\right)\right)} \]
    2. lower-*.f64N/A

      \[\leadsto \frac{1}{9} \cdot \left(a \cdot \color{blue}{\left(9 + rand \cdot \sqrt{\frac{9}{a}}\right)}\right) \]
    3. lower-+.f64N/A

      \[\leadsto \frac{1}{9} \cdot \left(a \cdot \left(9 + \color{blue}{rand \cdot \sqrt{\frac{9}{a}}}\right)\right) \]
    4. lower-*.f64N/A

      \[\leadsto \frac{1}{9} \cdot \left(a \cdot \left(9 + rand \cdot \color{blue}{\sqrt{\frac{9}{a}}}\right)\right) \]
    5. lower-sqrt.f64N/A

      \[\leadsto \frac{1}{9} \cdot \left(a \cdot \left(9 + rand \cdot \sqrt{\frac{9}{a}}\right)\right) \]
    6. lower-/.f6497.3%

      \[\leadsto 0.1111111111111111 \cdot \left(a \cdot \left(9 + rand \cdot \sqrt{\frac{9}{a}}\right)\right) \]
  5. Applied rewrites97.3%

    \[\leadsto \color{blue}{0.1111111111111111 \cdot \left(a \cdot \left(9 + rand \cdot \sqrt{\frac{9}{a}}\right)\right)} \]
  6. Taylor expanded in a around 0

    \[\leadsto a + \color{blue}{\frac{1}{9} \cdot \left(rand \cdot \sqrt{9 \cdot a}\right)} \]
  7. Step-by-step derivation
    1. lower-+.f64N/A

      \[\leadsto a + \frac{1}{9} \cdot \color{blue}{\left(rand \cdot \sqrt{9 \cdot a}\right)} \]
    2. lower-*.f64N/A

      \[\leadsto a + \frac{1}{9} \cdot \left(rand \cdot \color{blue}{\sqrt{9 \cdot a}}\right) \]
    3. lower-*.f64N/A

      \[\leadsto a + \frac{1}{9} \cdot \left(rand \cdot \sqrt{9 \cdot a}\right) \]
    4. lower-sqrt.f64N/A

      \[\leadsto a + \frac{1}{9} \cdot \left(rand \cdot \sqrt{9 \cdot a}\right) \]
    5. lower-*.f6497.7%

      \[\leadsto a + 0.1111111111111111 \cdot \left(rand \cdot \sqrt{9 \cdot a}\right) \]
  8. Applied rewrites97.7%

    \[\leadsto a + \color{blue}{0.1111111111111111 \cdot \left(rand \cdot \sqrt{9 \cdot a}\right)} \]
  9. Step-by-step derivation
    1. lift-+.f64N/A

      \[\leadsto a + \frac{1}{9} \cdot \color{blue}{\left(rand \cdot \sqrt{9 \cdot a}\right)} \]
    2. +-commutativeN/A

      \[\leadsto \frac{1}{9} \cdot \left(rand \cdot \sqrt{9 \cdot a}\right) + a \]
    3. lift-*.f64N/A

      \[\leadsto \frac{1}{9} \cdot \left(rand \cdot \sqrt{9 \cdot a}\right) + a \]
    4. lift-*.f64N/A

      \[\leadsto \frac{1}{9} \cdot \left(rand \cdot \sqrt{9 \cdot a}\right) + a \]
    5. associate-*r*N/A

      \[\leadsto \left(\frac{1}{9} \cdot rand\right) \cdot \sqrt{9 \cdot a} + a \]
    6. lower-fma.f64N/A

      \[\leadsto \mathsf{fma}\left(\frac{1}{9} \cdot rand, \sqrt{9 \cdot a}, a\right) \]
    7. lower-*.f6497.7%

      \[\leadsto \mathsf{fma}\left(0.1111111111111111 \cdot rand, \sqrt{9 \cdot a}, a\right) \]
  10. Applied rewrites97.7%

    \[\leadsto \mathsf{fma}\left(0.1111111111111111 \cdot rand, \sqrt{9 \cdot a}, a\right) \]
  11. Add Preprocessing

Alternative 9: 91.4% accurate, 1.7× speedup?

\[\begin{array}{l} t_0 := \frac{rand}{\sqrt{\frac{9}{a}}}\\ \mathbf{if}\;rand \leq -1.02 \cdot 10^{+116}:\\ \;\;\;\;t\_0\\ \mathbf{elif}\;rand \leq 1.05 \cdot 10^{+90}:\\ \;\;\;\;\left(a - 0.3333333333333333\right) \cdot 1\\ \mathbf{else}:\\ \;\;\;\;t\_0\\ \end{array} \]
(FPCore (a rand)
 :precision binary64
 (let* ((t_0 (/ rand (sqrt (/ 9.0 a)))))
   (if (<= rand -1.02e+116)
     t_0
     (if (<= rand 1.05e+90) (* (- a 0.3333333333333333) 1.0) t_0))))
double code(double a, double rand) {
	double t_0 = rand / sqrt((9.0 / a));
	double tmp;
	if (rand <= -1.02e+116) {
		tmp = t_0;
	} else if (rand <= 1.05e+90) {
		tmp = (a - 0.3333333333333333) * 1.0;
	} else {
		tmp = t_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(a, rand)
use fmin_fmax_functions
    real(8), intent (in) :: a
    real(8), intent (in) :: rand
    real(8) :: t_0
    real(8) :: tmp
    t_0 = rand / sqrt((9.0d0 / a))
    if (rand <= (-1.02d+116)) then
        tmp = t_0
    else if (rand <= 1.05d+90) then
        tmp = (a - 0.3333333333333333d0) * 1.0d0
    else
        tmp = t_0
    end if
    code = tmp
end function
public static double code(double a, double rand) {
	double t_0 = rand / Math.sqrt((9.0 / a));
	double tmp;
	if (rand <= -1.02e+116) {
		tmp = t_0;
	} else if (rand <= 1.05e+90) {
		tmp = (a - 0.3333333333333333) * 1.0;
	} else {
		tmp = t_0;
	}
	return tmp;
}
def code(a, rand):
	t_0 = rand / math.sqrt((9.0 / a))
	tmp = 0
	if rand <= -1.02e+116:
		tmp = t_0
	elif rand <= 1.05e+90:
		tmp = (a - 0.3333333333333333) * 1.0
	else:
		tmp = t_0
	return tmp
function code(a, rand)
	t_0 = Float64(rand / sqrt(Float64(9.0 / a)))
	tmp = 0.0
	if (rand <= -1.02e+116)
		tmp = t_0;
	elseif (rand <= 1.05e+90)
		tmp = Float64(Float64(a - 0.3333333333333333) * 1.0);
	else
		tmp = t_0;
	end
	return tmp
end
function tmp_2 = code(a, rand)
	t_0 = rand / sqrt((9.0 / a));
	tmp = 0.0;
	if (rand <= -1.02e+116)
		tmp = t_0;
	elseif (rand <= 1.05e+90)
		tmp = (a - 0.3333333333333333) * 1.0;
	else
		tmp = t_0;
	end
	tmp_2 = tmp;
end
code[a_, rand_] := Block[{t$95$0 = N[(rand / N[Sqrt[N[(9.0 / a), $MachinePrecision]], $MachinePrecision]), $MachinePrecision]}, If[LessEqual[rand, -1.02e+116], t$95$0, If[LessEqual[rand, 1.05e+90], N[(N[(a - 0.3333333333333333), $MachinePrecision] * 1.0), $MachinePrecision], t$95$0]]]
\begin{array}{l}
t_0 := \frac{rand}{\sqrt{\frac{9}{a}}}\\
\mathbf{if}\;rand \leq -1.02 \cdot 10^{+116}:\\
\;\;\;\;t\_0\\

\mathbf{elif}\;rand \leq 1.05 \cdot 10^{+90}:\\
\;\;\;\;\left(a - 0.3333333333333333\right) \cdot 1\\

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


\end{array}
Derivation
  1. Split input into 2 regimes
  2. if rand < -1.0199999999999999e116 or 1.0499999999999999e90 < rand

    1. Initial program 99.7%

      \[\left(a - \frac{1}{3}\right) \cdot \left(1 + \frac{1}{\sqrt{9 \cdot \left(a - \frac{1}{3}\right)}} \cdot rand\right) \]
    2. Taylor expanded in rand around inf

      \[\leadsto \color{blue}{\frac{rand \cdot \left(a - \frac{1}{3}\right)}{\sqrt{9 \cdot \left(a - \frac{1}{3}\right)}}} \]
    3. Step-by-step derivation
      1. metadata-evalN/A

        \[\leadsto \frac{rand \cdot \left(a - \frac{1}{3}\right)}{\sqrt{9 \cdot \left(a - \color{blue}{\frac{1}{3}}\right)}} \]
      2. metadata-evalN/A

        \[\leadsto \frac{rand \cdot \left(a - \frac{1}{3}\right)}{\sqrt{9 \cdot \left(a - \frac{1}{3}\right)}} \]
      3. lower-/.f64N/A

        \[\leadsto \frac{rand \cdot \left(a - \frac{1}{3}\right)}{\color{blue}{\sqrt{9 \cdot \left(a - \frac{1}{3}\right)}}} \]
      4. lower-*.f64N/A

        \[\leadsto \frac{rand \cdot \left(a - \frac{1}{3}\right)}{\sqrt{\color{blue}{9 \cdot \left(a - \frac{1}{3}\right)}}} \]
      5. lower--.f64N/A

        \[\leadsto \frac{rand \cdot \left(a - \frac{1}{3}\right)}{\sqrt{9 \cdot \color{blue}{\left(a - \frac{1}{3}\right)}}} \]
      6. metadata-evalN/A

        \[\leadsto \frac{rand \cdot \left(a - \frac{1}{3}\right)}{\sqrt{9 \cdot \left(a - \color{blue}{\frac{1}{3}}\right)}} \]
      7. lower-sqrt.f64N/A

        \[\leadsto \frac{rand \cdot \left(a - \frac{1}{3}\right)}{\sqrt{9 \cdot \left(a - \frac{1}{3}\right)}} \]
      8. lower-*.f64N/A

        \[\leadsto \frac{rand \cdot \left(a - \frac{1}{3}\right)}{\sqrt{9 \cdot \left(a - \frac{1}{3}\right)}} \]
      9. lower--.f64N/A

        \[\leadsto \frac{rand \cdot \left(a - \frac{1}{3}\right)}{\sqrt{9 \cdot \left(a - \frac{1}{3}\right)}} \]
      10. metadata-eval30.3%

        \[\leadsto \frac{rand \cdot \left(a - 0.3333333333333333\right)}{\sqrt{9 \cdot \left(a - 0.3333333333333333\right)}} \]
    4. Applied rewrites30.3%

      \[\leadsto \color{blue}{\frac{rand \cdot \left(a - 0.3333333333333333\right)}{\sqrt{9 \cdot \left(a - 0.3333333333333333\right)}}} \]
    5. Taylor expanded in a around inf

      \[\leadsto \frac{rand}{\color{blue}{\sqrt{\frac{9}{a}}}} \]
    6. Step-by-step derivation
      1. lower-/.f64N/A

        \[\leadsto \frac{rand}{\sqrt{\frac{9}{a}}} \]
      2. lower-sqrt.f64N/A

        \[\leadsto \frac{rand}{\sqrt{\frac{9}{a}}} \]
      3. lower-/.f6436.3%

        \[\leadsto \frac{rand}{\sqrt{\frac{9}{a}}} \]
    7. Applied rewrites36.3%

      \[\leadsto \frac{rand}{\color{blue}{\sqrt{\frac{9}{a}}}} \]

    if -1.0199999999999999e116 < rand < 1.0499999999999999e90

    1. Initial program 99.7%

      \[\left(a - \frac{1}{3}\right) \cdot \left(1 + \frac{1}{\sqrt{9 \cdot \left(a - \frac{1}{3}\right)}} \cdot rand\right) \]
    2. Taylor expanded in a around inf

      \[\leadsto \left(a - \frac{1}{3}\right) \cdot \color{blue}{1} \]
    3. Step-by-step derivation
      1. Applied rewrites63.8%

        \[\leadsto \left(a - \frac{1}{3}\right) \cdot \color{blue}{1} \]
      2. Step-by-step derivation
        1. lift-/.f64N/A

          \[\leadsto \left(a - \color{blue}{\frac{1}{3}}\right) \cdot 1 \]
        2. metadata-eval63.8%

          \[\leadsto \left(a - \color{blue}{0.3333333333333333}\right) \cdot 1 \]
      3. Applied rewrites63.8%

        \[\leadsto \color{blue}{\left(a - 0.3333333333333333\right) \cdot 1} \]
    4. Recombined 2 regimes into one program.
    5. Add Preprocessing

    Alternative 10: 63.8% accurate, 4.5× speedup?

    \[\left(a - 0.3333333333333333\right) \cdot 1 \]
    (FPCore (a rand) :precision binary64 (* (- a 0.3333333333333333) 1.0))
    double code(double a, double rand) {
    	return (a - 0.3333333333333333) * 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(a, rand)
    use fmin_fmax_functions
        real(8), intent (in) :: a
        real(8), intent (in) :: rand
        code = (a - 0.3333333333333333d0) * 1.0d0
    end function
    
    public static double code(double a, double rand) {
    	return (a - 0.3333333333333333) * 1.0;
    }
    
    def code(a, rand):
    	return (a - 0.3333333333333333) * 1.0
    
    function code(a, rand)
    	return Float64(Float64(a - 0.3333333333333333) * 1.0)
    end
    
    function tmp = code(a, rand)
    	tmp = (a - 0.3333333333333333) * 1.0;
    end
    
    code[a_, rand_] := N[(N[(a - 0.3333333333333333), $MachinePrecision] * 1.0), $MachinePrecision]
    
    \left(a - 0.3333333333333333\right) \cdot 1
    
    Derivation
    1. Initial program 99.7%

      \[\left(a - \frac{1}{3}\right) \cdot \left(1 + \frac{1}{\sqrt{9 \cdot \left(a - \frac{1}{3}\right)}} \cdot rand\right) \]
    2. Taylor expanded in a around inf

      \[\leadsto \left(a - \frac{1}{3}\right) \cdot \color{blue}{1} \]
    3. Step-by-step derivation
      1. Applied rewrites63.8%

        \[\leadsto \left(a - \frac{1}{3}\right) \cdot \color{blue}{1} \]
      2. Step-by-step derivation
        1. lift-/.f64N/A

          \[\leadsto \left(a - \color{blue}{\frac{1}{3}}\right) \cdot 1 \]
        2. metadata-eval63.8%

          \[\leadsto \left(a - \color{blue}{0.3333333333333333}\right) \cdot 1 \]
      3. Applied rewrites63.8%

        \[\leadsto \color{blue}{\left(a - 0.3333333333333333\right) \cdot 1} \]
      4. Add Preprocessing

      Reproduce

      ?
      herbie shell --seed 2025191 
      (FPCore (a rand)
        :name "Octave 3.8, oct_fill_randg"
        :precision binary64
        (* (- a (/ 1.0 3.0)) (+ 1.0 (* (/ 1.0 (sqrt (* 9.0 (- a (/ 1.0 3.0))))) rand))))