2tan (problem 3.3.2)

Percentage Accurate: 61.9% → 99.6%
Time: 9.8s
Alternatives: 17
Speedup: 76.4×

Specification

?
\[\left(\left(-10000 \leq x \land x \leq 10000\right) \land 10^{-16} \cdot \left|x\right| < \varepsilon\right) \land \varepsilon < \left|x\right|\]
\[\begin{array}{l} \\ \tan \left(x + \varepsilon\right) - \tan x \end{array} \]
(FPCore (x eps) :precision binary64 (- (tan (+ x eps)) (tan x)))
double code(double x, double eps) {
	return tan((x + eps)) - tan(x);
}
module fmin_fmax_functions
    implicit none
    private
    public fmax
    public fmin

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

real(8) function code(x, eps)
use fmin_fmax_functions
    real(8), intent (in) :: x
    real(8), intent (in) :: eps
    code = tan((x + eps)) - tan(x)
end function
public static double code(double x, double eps) {
	return Math.tan((x + eps)) - Math.tan(x);
}
def code(x, eps):
	return math.tan((x + eps)) - math.tan(x)
function code(x, eps)
	return Float64(tan(Float64(x + eps)) - tan(x))
end
function tmp = code(x, eps)
	tmp = tan((x + eps)) - tan(x);
end
code[x_, eps_] := N[(N[Tan[N[(x + eps), $MachinePrecision]], $MachinePrecision] - N[Tan[x], $MachinePrecision]), $MachinePrecision]
\begin{array}{l}

\\
\tan \left(x + \varepsilon\right) - \tan x
\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 17 alternatives:

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

Initial Program: 61.9% accurate, 1.0× speedup?

\[\begin{array}{l} \\ \tan \left(x + \varepsilon\right) - \tan x \end{array} \]
(FPCore (x eps) :precision binary64 (- (tan (+ x eps)) (tan x)))
double code(double x, double eps) {
	return tan((x + eps)) - tan(x);
}
module fmin_fmax_functions
    implicit none
    private
    public fmax
    public fmin

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

real(8) function code(x, eps)
use fmin_fmax_functions
    real(8), intent (in) :: x
    real(8), intent (in) :: eps
    code = tan((x + eps)) - tan(x)
end function
public static double code(double x, double eps) {
	return Math.tan((x + eps)) - Math.tan(x);
}
def code(x, eps):
	return math.tan((x + eps)) - math.tan(x)
function code(x, eps)
	return Float64(tan(Float64(x + eps)) - tan(x))
end
function tmp = code(x, eps)
	tmp = tan((x + eps)) - tan(x);
end
code[x_, eps_] := N[(N[Tan[N[(x + eps), $MachinePrecision]], $MachinePrecision] - N[Tan[x], $MachinePrecision]), $MachinePrecision]
\begin{array}{l}

\\
\tan \left(x + \varepsilon\right) - \tan x
\end{array}

Alternative 1: 99.6% accurate, 0.2× speedup?

\[\begin{array}{l} \\ \begin{array}{l} t_0 := {\tan x}^{2}\\ t_1 := t\_0 - -1\\ \mathsf{fma}\left(\mathsf{fma}\left(\mathsf{fma}\left(t\_0, t\_1, -0.16666666666666666\right) - \mathsf{fma}\left(t\_0, -0.3333333333333333, -0.5\right), \varepsilon, t\_1 \cdot \tan x\right), \varepsilon, t\_1\right) \cdot \varepsilon \end{array} \end{array} \]
(FPCore (x eps)
 :precision binary64
 (let* ((t_0 (pow (tan x) 2.0)) (t_1 (- t_0 -1.0)))
   (*
    (fma
     (fma
      (- (fma t_0 t_1 -0.16666666666666666) (fma t_0 -0.3333333333333333 -0.5))
      eps
      (* t_1 (tan x)))
     eps
     t_1)
    eps)))
double code(double x, double eps) {
	double t_0 = pow(tan(x), 2.0);
	double t_1 = t_0 - -1.0;
	return fma(fma((fma(t_0, t_1, -0.16666666666666666) - fma(t_0, -0.3333333333333333, -0.5)), eps, (t_1 * tan(x))), eps, t_1) * eps;
}
function code(x, eps)
	t_0 = tan(x) ^ 2.0
	t_1 = Float64(t_0 - -1.0)
	return Float64(fma(fma(Float64(fma(t_0, t_1, -0.16666666666666666) - fma(t_0, -0.3333333333333333, -0.5)), eps, Float64(t_1 * tan(x))), eps, t_1) * eps)
end
code[x_, eps_] := Block[{t$95$0 = N[Power[N[Tan[x], $MachinePrecision], 2.0], $MachinePrecision]}, Block[{t$95$1 = N[(t$95$0 - -1.0), $MachinePrecision]}, N[(N[(N[(N[(N[(t$95$0 * t$95$1 + -0.16666666666666666), $MachinePrecision] - N[(t$95$0 * -0.3333333333333333 + -0.5), $MachinePrecision]), $MachinePrecision] * eps + N[(t$95$1 * N[Tan[x], $MachinePrecision]), $MachinePrecision]), $MachinePrecision] * eps + t$95$1), $MachinePrecision] * eps), $MachinePrecision]]]
\begin{array}{l}

\\
\begin{array}{l}
t_0 := {\tan x}^{2}\\
t_1 := t\_0 - -1\\
\mathsf{fma}\left(\mathsf{fma}\left(\mathsf{fma}\left(t\_0, t\_1, -0.16666666666666666\right) - \mathsf{fma}\left(t\_0, -0.3333333333333333, -0.5\right), \varepsilon, t\_1 \cdot \tan x\right), \varepsilon, t\_1\right) \cdot \varepsilon
\end{array}
\end{array}
Derivation
  1. Initial program 61.9%

    \[\tan \left(x + \varepsilon\right) - \tan x \]
  2. Taylor expanded in eps around 0

    \[\leadsto \color{blue}{\varepsilon \cdot \left(\left(1 + \varepsilon \cdot \left(-1 \cdot \left(\varepsilon \cdot \left(\frac{1}{6} + \left(-1 \cdot \frac{{\sin x}^{2} \cdot \left(1 - -1 \cdot \frac{{\sin x}^{2}}{{\cos x}^{2}}\right)}{{\cos x}^{2}} + \left(\frac{-1}{2} \cdot \left(1 - -1 \cdot \frac{{\sin x}^{2}}{{\cos x}^{2}}\right) + \frac{1}{6} \cdot \frac{{\sin x}^{2}}{{\cos x}^{2}}\right)\right)\right)\right) - -1 \cdot \frac{\sin x \cdot \left(1 - -1 \cdot \frac{{\sin x}^{2}}{{\cos x}^{2}}\right)}{\cos x}\right)\right) - -1 \cdot \frac{{\sin x}^{2}}{{\cos x}^{2}}\right)} \]
  3. Applied rewrites99.6%

    \[\leadsto \color{blue}{\varepsilon \cdot \left(\left(1 + \varepsilon \cdot \left(-1 \cdot \left(\varepsilon \cdot \left(0.16666666666666666 + \mathsf{fma}\left(-1, \frac{{\sin x}^{2} \cdot \left(1 - -1 \cdot \frac{{\sin x}^{2}}{{\cos x}^{2}}\right)}{{\cos x}^{2}}, \mathsf{fma}\left(-0.5, 1 - -1 \cdot \frac{{\sin x}^{2}}{{\cos x}^{2}}, 0.16666666666666666 \cdot \frac{{\sin x}^{2}}{{\cos x}^{2}}\right)\right)\right)\right) - -1 \cdot \frac{\sin x \cdot \left(1 - -1 \cdot \frac{{\sin x}^{2}}{{\cos x}^{2}}\right)}{\cos x}\right)\right) - -1 \cdot \frac{{\sin x}^{2}}{{\cos x}^{2}}\right)} \]
  4. Applied rewrites99.6%

    \[\leadsto \color{blue}{\mathsf{fma}\left(\mathsf{fma}\left(\left(\mathsf{fma}\left(-0.5, \mathsf{fma}\left(\tan x, \tan x, 1\right), 0.16666666666666666 \cdot \left(\tan x \cdot \tan x\right)\right) - \mathsf{fma}\left(\tan x, \tan x, 1\right) \cdot \left(\tan x \cdot \tan x\right)\right) - -0.16666666666666666, -\varepsilon, \mathsf{fma}\left(\tan x, \tan x, 1\right) \cdot \tan x\right), \varepsilon, \mathsf{fma}\left(\tan x, \tan x, 1\right)\right) \cdot \varepsilon} \]
  5. Applied rewrites99.6%

    \[\leadsto \mathsf{fma}\left(\mathsf{fma}\left(\mathsf{fma}\left(0.16666666666666666, {\tan x}^{2}, \mathsf{fma}\left({\tan x}^{2}, -0.5, -0.5\right)\right) - \mathsf{fma}\left({\tan x}^{2}, {\tan x}^{2} - -1, -0.16666666666666666\right), -\varepsilon, \left({\tan x}^{2} - -1\right) \cdot \tan x\right), \varepsilon, {\tan x}^{2} - -1\right) \cdot \color{blue}{\varepsilon} \]
  6. Applied rewrites99.6%

    \[\leadsto \color{blue}{\mathsf{fma}\left(\mathsf{fma}\left(\mathsf{fma}\left({\tan x}^{2}, {\tan x}^{2} - -1, -0.16666666666666666\right) - \mathsf{fma}\left({\tan x}^{2}, -0.3333333333333333, -0.5\right), \varepsilon, \left({\tan x}^{2} - -1\right) \cdot \tan x\right), \varepsilon, {\tan x}^{2} - -1\right) \cdot \varepsilon} \]
  7. Add Preprocessing

Alternative 2: 99.6% accurate, 0.2× speedup?

\[\begin{array}{l} \\ \begin{array}{l} t_0 := {\tan x}^{2}\\ t_1 := t\_0 - -1\\ \left(\mathsf{fma}\left(\mathsf{fma}\left(\mathsf{fma}\left(t\_0, t\_1, -0.16666666666666666\right) - \mathsf{fma}\left(t\_0, -0.3333333333333333, -0.5\right), \varepsilon, t\_1 \cdot \tan x\right), \varepsilon, t\_0\right) - -1\right) \cdot \varepsilon \end{array} \end{array} \]
(FPCore (x eps)
 :precision binary64
 (let* ((t_0 (pow (tan x) 2.0)) (t_1 (- t_0 -1.0)))
   (*
    (-
     (fma
      (fma
       (-
        (fma t_0 t_1 -0.16666666666666666)
        (fma t_0 -0.3333333333333333 -0.5))
       eps
       (* t_1 (tan x)))
      eps
      t_0)
     -1.0)
    eps)))
double code(double x, double eps) {
	double t_0 = pow(tan(x), 2.0);
	double t_1 = t_0 - -1.0;
	return (fma(fma((fma(t_0, t_1, -0.16666666666666666) - fma(t_0, -0.3333333333333333, -0.5)), eps, (t_1 * tan(x))), eps, t_0) - -1.0) * eps;
}
function code(x, eps)
	t_0 = tan(x) ^ 2.0
	t_1 = Float64(t_0 - -1.0)
	return Float64(Float64(fma(fma(Float64(fma(t_0, t_1, -0.16666666666666666) - fma(t_0, -0.3333333333333333, -0.5)), eps, Float64(t_1 * tan(x))), eps, t_0) - -1.0) * eps)
end
code[x_, eps_] := Block[{t$95$0 = N[Power[N[Tan[x], $MachinePrecision], 2.0], $MachinePrecision]}, Block[{t$95$1 = N[(t$95$0 - -1.0), $MachinePrecision]}, N[(N[(N[(N[(N[(N[(t$95$0 * t$95$1 + -0.16666666666666666), $MachinePrecision] - N[(t$95$0 * -0.3333333333333333 + -0.5), $MachinePrecision]), $MachinePrecision] * eps + N[(t$95$1 * N[Tan[x], $MachinePrecision]), $MachinePrecision]), $MachinePrecision] * eps + t$95$0), $MachinePrecision] - -1.0), $MachinePrecision] * eps), $MachinePrecision]]]
\begin{array}{l}

\\
\begin{array}{l}
t_0 := {\tan x}^{2}\\
t_1 := t\_0 - -1\\
\left(\mathsf{fma}\left(\mathsf{fma}\left(\mathsf{fma}\left(t\_0, t\_1, -0.16666666666666666\right) - \mathsf{fma}\left(t\_0, -0.3333333333333333, -0.5\right), \varepsilon, t\_1 \cdot \tan x\right), \varepsilon, t\_0\right) - -1\right) \cdot \varepsilon
\end{array}
\end{array}
Derivation
  1. Initial program 61.9%

    \[\tan \left(x + \varepsilon\right) - \tan x \]
  2. Taylor expanded in eps around 0

    \[\leadsto \color{blue}{\varepsilon \cdot \left(\left(1 + \varepsilon \cdot \left(-1 \cdot \left(\varepsilon \cdot \left(\frac{1}{6} + \left(-1 \cdot \frac{{\sin x}^{2} \cdot \left(1 - -1 \cdot \frac{{\sin x}^{2}}{{\cos x}^{2}}\right)}{{\cos x}^{2}} + \left(\frac{-1}{2} \cdot \left(1 - -1 \cdot \frac{{\sin x}^{2}}{{\cos x}^{2}}\right) + \frac{1}{6} \cdot \frac{{\sin x}^{2}}{{\cos x}^{2}}\right)\right)\right)\right) - -1 \cdot \frac{\sin x \cdot \left(1 - -1 \cdot \frac{{\sin x}^{2}}{{\cos x}^{2}}\right)}{\cos x}\right)\right) - -1 \cdot \frac{{\sin x}^{2}}{{\cos x}^{2}}\right)} \]
  3. Applied rewrites99.6%

    \[\leadsto \color{blue}{\varepsilon \cdot \left(\left(1 + \varepsilon \cdot \left(-1 \cdot \left(\varepsilon \cdot \left(0.16666666666666666 + \mathsf{fma}\left(-1, \frac{{\sin x}^{2} \cdot \left(1 - -1 \cdot \frac{{\sin x}^{2}}{{\cos x}^{2}}\right)}{{\cos x}^{2}}, \mathsf{fma}\left(-0.5, 1 - -1 \cdot \frac{{\sin x}^{2}}{{\cos x}^{2}}, 0.16666666666666666 \cdot \frac{{\sin x}^{2}}{{\cos x}^{2}}\right)\right)\right)\right) - -1 \cdot \frac{\sin x \cdot \left(1 - -1 \cdot \frac{{\sin x}^{2}}{{\cos x}^{2}}\right)}{\cos x}\right)\right) - -1 \cdot \frac{{\sin x}^{2}}{{\cos x}^{2}}\right)} \]
  4. Applied rewrites99.6%

    \[\leadsto \color{blue}{\mathsf{fma}\left(\mathsf{fma}\left(\left(\mathsf{fma}\left(-0.5, \mathsf{fma}\left(\tan x, \tan x, 1\right), 0.16666666666666666 \cdot \left(\tan x \cdot \tan x\right)\right) - \mathsf{fma}\left(\tan x, \tan x, 1\right) \cdot \left(\tan x \cdot \tan x\right)\right) - -0.16666666666666666, -\varepsilon, \mathsf{fma}\left(\tan x, \tan x, 1\right) \cdot \tan x\right), \varepsilon, \mathsf{fma}\left(\tan x, \tan x, 1\right)\right) \cdot \varepsilon} \]
  5. Applied rewrites99.6%

    \[\leadsto \mathsf{fma}\left(\mathsf{fma}\left(\mathsf{fma}\left(0.16666666666666666, {\tan x}^{2}, \mathsf{fma}\left({\tan x}^{2}, -0.5, -0.5\right)\right) - \mathsf{fma}\left({\tan x}^{2}, {\tan x}^{2} - -1, -0.16666666666666666\right), -\varepsilon, \left({\tan x}^{2} - -1\right) \cdot \tan x\right), \varepsilon, {\tan x}^{2} - -1\right) \cdot \color{blue}{\varepsilon} \]
  6. Applied rewrites99.6%

    \[\leadsto \left(\mathsf{fma}\left(\mathsf{fma}\left(\mathsf{fma}\left({\tan x}^{2}, {\tan x}^{2} - -1, -0.16666666666666666\right) - \mathsf{fma}\left({\tan x}^{2}, -0.3333333333333333, -0.5\right), \varepsilon, \left({\tan x}^{2} - -1\right) \cdot \tan x\right), \varepsilon, {\tan x}^{2}\right) - -1\right) \cdot \varepsilon \]
  7. Add Preprocessing

Alternative 3: 99.5% accurate, 0.2× speedup?

\[\begin{array}{l} \\ \begin{array}{l} t_0 := {\tan x}^{2}\\ t_1 := t\_0 - -1\\ \mathsf{fma}\left(\mathsf{fma}\left(\left({x}^{2} \cdot \left(-0.2222222222222222 \cdot {x}^{2} - 0.3333333333333333\right) - 0.5\right) - \mathsf{fma}\left(t\_0, t\_1, -0.16666666666666666\right), -\varepsilon, t\_1 \cdot \tan x\right), \varepsilon, t\_1\right) \cdot \varepsilon \end{array} \end{array} \]
(FPCore (x eps)
 :precision binary64
 (let* ((t_0 (pow (tan x) 2.0)) (t_1 (- t_0 -1.0)))
   (*
    (fma
     (fma
      (-
       (-
        (*
         (pow x 2.0)
         (- (* -0.2222222222222222 (pow x 2.0)) 0.3333333333333333))
        0.5)
       (fma t_0 t_1 -0.16666666666666666))
      (- eps)
      (* t_1 (tan x)))
     eps
     t_1)
    eps)))
double code(double x, double eps) {
	double t_0 = pow(tan(x), 2.0);
	double t_1 = t_0 - -1.0;
	return fma(fma((((pow(x, 2.0) * ((-0.2222222222222222 * pow(x, 2.0)) - 0.3333333333333333)) - 0.5) - fma(t_0, t_1, -0.16666666666666666)), -eps, (t_1 * tan(x))), eps, t_1) * eps;
}
function code(x, eps)
	t_0 = tan(x) ^ 2.0
	t_1 = Float64(t_0 - -1.0)
	return Float64(fma(fma(Float64(Float64(Float64((x ^ 2.0) * Float64(Float64(-0.2222222222222222 * (x ^ 2.0)) - 0.3333333333333333)) - 0.5) - fma(t_0, t_1, -0.16666666666666666)), Float64(-eps), Float64(t_1 * tan(x))), eps, t_1) * eps)
end
code[x_, eps_] := Block[{t$95$0 = N[Power[N[Tan[x], $MachinePrecision], 2.0], $MachinePrecision]}, Block[{t$95$1 = N[(t$95$0 - -1.0), $MachinePrecision]}, N[(N[(N[(N[(N[(N[(N[Power[x, 2.0], $MachinePrecision] * N[(N[(-0.2222222222222222 * N[Power[x, 2.0], $MachinePrecision]), $MachinePrecision] - 0.3333333333333333), $MachinePrecision]), $MachinePrecision] - 0.5), $MachinePrecision] - N[(t$95$0 * t$95$1 + -0.16666666666666666), $MachinePrecision]), $MachinePrecision] * (-eps) + N[(t$95$1 * N[Tan[x], $MachinePrecision]), $MachinePrecision]), $MachinePrecision] * eps + t$95$1), $MachinePrecision] * eps), $MachinePrecision]]]
\begin{array}{l}

\\
\begin{array}{l}
t_0 := {\tan x}^{2}\\
t_1 := t\_0 - -1\\
\mathsf{fma}\left(\mathsf{fma}\left(\left({x}^{2} \cdot \left(-0.2222222222222222 \cdot {x}^{2} - 0.3333333333333333\right) - 0.5\right) - \mathsf{fma}\left(t\_0, t\_1, -0.16666666666666666\right), -\varepsilon, t\_1 \cdot \tan x\right), \varepsilon, t\_1\right) \cdot \varepsilon
\end{array}
\end{array}
Derivation
  1. Initial program 61.9%

    \[\tan \left(x + \varepsilon\right) - \tan x \]
  2. Taylor expanded in eps around 0

    \[\leadsto \color{blue}{\varepsilon \cdot \left(\left(1 + \varepsilon \cdot \left(-1 \cdot \left(\varepsilon \cdot \left(\frac{1}{6} + \left(-1 \cdot \frac{{\sin x}^{2} \cdot \left(1 - -1 \cdot \frac{{\sin x}^{2}}{{\cos x}^{2}}\right)}{{\cos x}^{2}} + \left(\frac{-1}{2} \cdot \left(1 - -1 \cdot \frac{{\sin x}^{2}}{{\cos x}^{2}}\right) + \frac{1}{6} \cdot \frac{{\sin x}^{2}}{{\cos x}^{2}}\right)\right)\right)\right) - -1 \cdot \frac{\sin x \cdot \left(1 - -1 \cdot \frac{{\sin x}^{2}}{{\cos x}^{2}}\right)}{\cos x}\right)\right) - -1 \cdot \frac{{\sin x}^{2}}{{\cos x}^{2}}\right)} \]
  3. Applied rewrites99.6%

    \[\leadsto \color{blue}{\varepsilon \cdot \left(\left(1 + \varepsilon \cdot \left(-1 \cdot \left(\varepsilon \cdot \left(0.16666666666666666 + \mathsf{fma}\left(-1, \frac{{\sin x}^{2} \cdot \left(1 - -1 \cdot \frac{{\sin x}^{2}}{{\cos x}^{2}}\right)}{{\cos x}^{2}}, \mathsf{fma}\left(-0.5, 1 - -1 \cdot \frac{{\sin x}^{2}}{{\cos x}^{2}}, 0.16666666666666666 \cdot \frac{{\sin x}^{2}}{{\cos x}^{2}}\right)\right)\right)\right) - -1 \cdot \frac{\sin x \cdot \left(1 - -1 \cdot \frac{{\sin x}^{2}}{{\cos x}^{2}}\right)}{\cos x}\right)\right) - -1 \cdot \frac{{\sin x}^{2}}{{\cos x}^{2}}\right)} \]
  4. Applied rewrites99.6%

    \[\leadsto \color{blue}{\mathsf{fma}\left(\mathsf{fma}\left(\left(\mathsf{fma}\left(-0.5, \mathsf{fma}\left(\tan x, \tan x, 1\right), 0.16666666666666666 \cdot \left(\tan x \cdot \tan x\right)\right) - \mathsf{fma}\left(\tan x, \tan x, 1\right) \cdot \left(\tan x \cdot \tan x\right)\right) - -0.16666666666666666, -\varepsilon, \mathsf{fma}\left(\tan x, \tan x, 1\right) \cdot \tan x\right), \varepsilon, \mathsf{fma}\left(\tan x, \tan x, 1\right)\right) \cdot \varepsilon} \]
  5. Applied rewrites99.6%

    \[\leadsto \mathsf{fma}\left(\mathsf{fma}\left(\mathsf{fma}\left(0.16666666666666666, {\tan x}^{2}, \mathsf{fma}\left({\tan x}^{2}, -0.5, -0.5\right)\right) - \mathsf{fma}\left({\tan x}^{2}, {\tan x}^{2} - -1, -0.16666666666666666\right), -\varepsilon, \left({\tan x}^{2} - -1\right) \cdot \tan x\right), \varepsilon, {\tan x}^{2} - -1\right) \cdot \color{blue}{\varepsilon} \]
  6. Taylor expanded in x around 0

    \[\leadsto \mathsf{fma}\left(\mathsf{fma}\left(\left({x}^{2} \cdot \left(\frac{-2}{9} \cdot {x}^{2} - \frac{1}{3}\right) - \frac{1}{2}\right) - \mathsf{fma}\left({\tan x}^{2}, {\tan x}^{2} - -1, \frac{-1}{6}\right), -\varepsilon, \left({\tan x}^{2} - -1\right) \cdot \tan x\right), \varepsilon, {\tan x}^{2} - -1\right) \cdot \varepsilon \]
  7. Applied rewrites99.4%

    \[\leadsto \mathsf{fma}\left(\mathsf{fma}\left(\left({x}^{2} \cdot \left(-0.2222222222222222 \cdot {x}^{2} - 0.3333333333333333\right) - 0.5\right) - \mathsf{fma}\left({\tan x}^{2}, {\tan x}^{2} - -1, -0.16666666666666666\right), -\varepsilon, \left({\tan x}^{2} - -1\right) \cdot \tan x\right), \varepsilon, {\tan x}^{2} - -1\right) \cdot \varepsilon \]
  8. Add Preprocessing

Alternative 4: 99.5% accurate, 0.3× speedup?

\[\begin{array}{l} \\ \begin{array}{l} t_0 := {\tan x}^{2}\\ t_1 := t\_0 - -1\\ \mathsf{fma}\left(\mathsf{fma}\left(\left(-0.3333333333333333 \cdot {x}^{2} - 0.5\right) - \mathsf{fma}\left(t\_0, t\_1, -0.16666666666666666\right), -\varepsilon, t\_1 \cdot \tan x\right), \varepsilon, t\_1\right) \cdot \varepsilon \end{array} \end{array} \]
(FPCore (x eps)
 :precision binary64
 (let* ((t_0 (pow (tan x) 2.0)) (t_1 (- t_0 -1.0)))
   (*
    (fma
     (fma
      (-
       (- (* -0.3333333333333333 (pow x 2.0)) 0.5)
       (fma t_0 t_1 -0.16666666666666666))
      (- eps)
      (* t_1 (tan x)))
     eps
     t_1)
    eps)))
double code(double x, double eps) {
	double t_0 = pow(tan(x), 2.0);
	double t_1 = t_0 - -1.0;
	return fma(fma((((-0.3333333333333333 * pow(x, 2.0)) - 0.5) - fma(t_0, t_1, -0.16666666666666666)), -eps, (t_1 * tan(x))), eps, t_1) * eps;
}
function code(x, eps)
	t_0 = tan(x) ^ 2.0
	t_1 = Float64(t_0 - -1.0)
	return Float64(fma(fma(Float64(Float64(Float64(-0.3333333333333333 * (x ^ 2.0)) - 0.5) - fma(t_0, t_1, -0.16666666666666666)), Float64(-eps), Float64(t_1 * tan(x))), eps, t_1) * eps)
end
code[x_, eps_] := Block[{t$95$0 = N[Power[N[Tan[x], $MachinePrecision], 2.0], $MachinePrecision]}, Block[{t$95$1 = N[(t$95$0 - -1.0), $MachinePrecision]}, N[(N[(N[(N[(N[(N[(-0.3333333333333333 * N[Power[x, 2.0], $MachinePrecision]), $MachinePrecision] - 0.5), $MachinePrecision] - N[(t$95$0 * t$95$1 + -0.16666666666666666), $MachinePrecision]), $MachinePrecision] * (-eps) + N[(t$95$1 * N[Tan[x], $MachinePrecision]), $MachinePrecision]), $MachinePrecision] * eps + t$95$1), $MachinePrecision] * eps), $MachinePrecision]]]
\begin{array}{l}

\\
\begin{array}{l}
t_0 := {\tan x}^{2}\\
t_1 := t\_0 - -1\\
\mathsf{fma}\left(\mathsf{fma}\left(\left(-0.3333333333333333 \cdot {x}^{2} - 0.5\right) - \mathsf{fma}\left(t\_0, t\_1, -0.16666666666666666\right), -\varepsilon, t\_1 \cdot \tan x\right), \varepsilon, t\_1\right) \cdot \varepsilon
\end{array}
\end{array}
Derivation
  1. Initial program 61.9%

    \[\tan \left(x + \varepsilon\right) - \tan x \]
  2. Taylor expanded in eps around 0

    \[\leadsto \color{blue}{\varepsilon \cdot \left(\left(1 + \varepsilon \cdot \left(-1 \cdot \left(\varepsilon \cdot \left(\frac{1}{6} + \left(-1 \cdot \frac{{\sin x}^{2} \cdot \left(1 - -1 \cdot \frac{{\sin x}^{2}}{{\cos x}^{2}}\right)}{{\cos x}^{2}} + \left(\frac{-1}{2} \cdot \left(1 - -1 \cdot \frac{{\sin x}^{2}}{{\cos x}^{2}}\right) + \frac{1}{6} \cdot \frac{{\sin x}^{2}}{{\cos x}^{2}}\right)\right)\right)\right) - -1 \cdot \frac{\sin x \cdot \left(1 - -1 \cdot \frac{{\sin x}^{2}}{{\cos x}^{2}}\right)}{\cos x}\right)\right) - -1 \cdot \frac{{\sin x}^{2}}{{\cos x}^{2}}\right)} \]
  3. Applied rewrites99.6%

    \[\leadsto \color{blue}{\varepsilon \cdot \left(\left(1 + \varepsilon \cdot \left(-1 \cdot \left(\varepsilon \cdot \left(0.16666666666666666 + \mathsf{fma}\left(-1, \frac{{\sin x}^{2} \cdot \left(1 - -1 \cdot \frac{{\sin x}^{2}}{{\cos x}^{2}}\right)}{{\cos x}^{2}}, \mathsf{fma}\left(-0.5, 1 - -1 \cdot \frac{{\sin x}^{2}}{{\cos x}^{2}}, 0.16666666666666666 \cdot \frac{{\sin x}^{2}}{{\cos x}^{2}}\right)\right)\right)\right) - -1 \cdot \frac{\sin x \cdot \left(1 - -1 \cdot \frac{{\sin x}^{2}}{{\cos x}^{2}}\right)}{\cos x}\right)\right) - -1 \cdot \frac{{\sin x}^{2}}{{\cos x}^{2}}\right)} \]
  4. Applied rewrites99.6%

    \[\leadsto \color{blue}{\mathsf{fma}\left(\mathsf{fma}\left(\left(\mathsf{fma}\left(-0.5, \mathsf{fma}\left(\tan x, \tan x, 1\right), 0.16666666666666666 \cdot \left(\tan x \cdot \tan x\right)\right) - \mathsf{fma}\left(\tan x, \tan x, 1\right) \cdot \left(\tan x \cdot \tan x\right)\right) - -0.16666666666666666, -\varepsilon, \mathsf{fma}\left(\tan x, \tan x, 1\right) \cdot \tan x\right), \varepsilon, \mathsf{fma}\left(\tan x, \tan x, 1\right)\right) \cdot \varepsilon} \]
  5. Applied rewrites99.6%

    \[\leadsto \mathsf{fma}\left(\mathsf{fma}\left(\mathsf{fma}\left(0.16666666666666666, {\tan x}^{2}, \mathsf{fma}\left({\tan x}^{2}, -0.5, -0.5\right)\right) - \mathsf{fma}\left({\tan x}^{2}, {\tan x}^{2} - -1, -0.16666666666666666\right), -\varepsilon, \left({\tan x}^{2} - -1\right) \cdot \tan x\right), \varepsilon, {\tan x}^{2} - -1\right) \cdot \color{blue}{\varepsilon} \]
  6. Taylor expanded in x around 0

    \[\leadsto \mathsf{fma}\left(\mathsf{fma}\left(\left(\frac{-1}{3} \cdot {x}^{2} - \frac{1}{2}\right) - \mathsf{fma}\left({\tan x}^{2}, {\tan x}^{2} - -1, \frac{-1}{6}\right), -\varepsilon, \left({\tan x}^{2} - -1\right) \cdot \tan x\right), \varepsilon, {\tan x}^{2} - -1\right) \cdot \varepsilon \]
  7. Applied rewrites99.5%

    \[\leadsto \mathsf{fma}\left(\mathsf{fma}\left(\left(-0.3333333333333333 \cdot {x}^{2} - 0.5\right) - \mathsf{fma}\left({\tan x}^{2}, {\tan x}^{2} - -1, -0.16666666666666666\right), -\varepsilon, \left({\tan x}^{2} - -1\right) \cdot \tan x\right), \varepsilon, {\tan x}^{2} - -1\right) \cdot \varepsilon \]
  8. Add Preprocessing

Alternative 5: 99.4% accurate, 0.3× speedup?

\[\begin{array}{l} \\ \begin{array}{l} t_0 := {\tan x}^{2} - -1\\ \mathsf{fma}\left(\mathsf{fma}\left({x}^{2} \cdot \left({x}^{2} \cdot \left(-1.837037037037037 \cdot {x}^{2} - 1.8888888888888888\right) - 1.3333333333333333\right) - 0.3333333333333333, -\varepsilon, t\_0 \cdot \tan x\right), \varepsilon, t\_0\right) \cdot \varepsilon \end{array} \end{array} \]
(FPCore (x eps)
 :precision binary64
 (let* ((t_0 (- (pow (tan x) 2.0) -1.0)))
   (*
    (fma
     (fma
      (-
       (*
        (pow x 2.0)
        (-
         (*
          (pow x 2.0)
          (- (* -1.837037037037037 (pow x 2.0)) 1.8888888888888888))
         1.3333333333333333))
       0.3333333333333333)
      (- eps)
      (* t_0 (tan x)))
     eps
     t_0)
    eps)))
double code(double x, double eps) {
	double t_0 = pow(tan(x), 2.0) - -1.0;
	return fma(fma(((pow(x, 2.0) * ((pow(x, 2.0) * ((-1.837037037037037 * pow(x, 2.0)) - 1.8888888888888888)) - 1.3333333333333333)) - 0.3333333333333333), -eps, (t_0 * tan(x))), eps, t_0) * eps;
}
function code(x, eps)
	t_0 = Float64((tan(x) ^ 2.0) - -1.0)
	return Float64(fma(fma(Float64(Float64((x ^ 2.0) * Float64(Float64((x ^ 2.0) * Float64(Float64(-1.837037037037037 * (x ^ 2.0)) - 1.8888888888888888)) - 1.3333333333333333)) - 0.3333333333333333), Float64(-eps), Float64(t_0 * tan(x))), eps, t_0) * eps)
end
code[x_, eps_] := Block[{t$95$0 = N[(N[Power[N[Tan[x], $MachinePrecision], 2.0], $MachinePrecision] - -1.0), $MachinePrecision]}, N[(N[(N[(N[(N[(N[Power[x, 2.0], $MachinePrecision] * N[(N[(N[Power[x, 2.0], $MachinePrecision] * N[(N[(-1.837037037037037 * N[Power[x, 2.0], $MachinePrecision]), $MachinePrecision] - 1.8888888888888888), $MachinePrecision]), $MachinePrecision] - 1.3333333333333333), $MachinePrecision]), $MachinePrecision] - 0.3333333333333333), $MachinePrecision] * (-eps) + N[(t$95$0 * N[Tan[x], $MachinePrecision]), $MachinePrecision]), $MachinePrecision] * eps + t$95$0), $MachinePrecision] * eps), $MachinePrecision]]
\begin{array}{l}

\\
\begin{array}{l}
t_0 := {\tan x}^{2} - -1\\
\mathsf{fma}\left(\mathsf{fma}\left({x}^{2} \cdot \left({x}^{2} \cdot \left(-1.837037037037037 \cdot {x}^{2} - 1.8888888888888888\right) - 1.3333333333333333\right) - 0.3333333333333333, -\varepsilon, t\_0 \cdot \tan x\right), \varepsilon, t\_0\right) \cdot \varepsilon
\end{array}
\end{array}
Derivation
  1. Initial program 61.9%

    \[\tan \left(x + \varepsilon\right) - \tan x \]
  2. Taylor expanded in eps around 0

    \[\leadsto \color{blue}{\varepsilon \cdot \left(\left(1 + \varepsilon \cdot \left(-1 \cdot \left(\varepsilon \cdot \left(\frac{1}{6} + \left(-1 \cdot \frac{{\sin x}^{2} \cdot \left(1 - -1 \cdot \frac{{\sin x}^{2}}{{\cos x}^{2}}\right)}{{\cos x}^{2}} + \left(\frac{-1}{2} \cdot \left(1 - -1 \cdot \frac{{\sin x}^{2}}{{\cos x}^{2}}\right) + \frac{1}{6} \cdot \frac{{\sin x}^{2}}{{\cos x}^{2}}\right)\right)\right)\right) - -1 \cdot \frac{\sin x \cdot \left(1 - -1 \cdot \frac{{\sin x}^{2}}{{\cos x}^{2}}\right)}{\cos x}\right)\right) - -1 \cdot \frac{{\sin x}^{2}}{{\cos x}^{2}}\right)} \]
  3. Applied rewrites99.6%

    \[\leadsto \color{blue}{\varepsilon \cdot \left(\left(1 + \varepsilon \cdot \left(-1 \cdot \left(\varepsilon \cdot \left(0.16666666666666666 + \mathsf{fma}\left(-1, \frac{{\sin x}^{2} \cdot \left(1 - -1 \cdot \frac{{\sin x}^{2}}{{\cos x}^{2}}\right)}{{\cos x}^{2}}, \mathsf{fma}\left(-0.5, 1 - -1 \cdot \frac{{\sin x}^{2}}{{\cos x}^{2}}, 0.16666666666666666 \cdot \frac{{\sin x}^{2}}{{\cos x}^{2}}\right)\right)\right)\right) - -1 \cdot \frac{\sin x \cdot \left(1 - -1 \cdot \frac{{\sin x}^{2}}{{\cos x}^{2}}\right)}{\cos x}\right)\right) - -1 \cdot \frac{{\sin x}^{2}}{{\cos x}^{2}}\right)} \]
  4. Applied rewrites99.6%

    \[\leadsto \color{blue}{\mathsf{fma}\left(\mathsf{fma}\left(\left(\mathsf{fma}\left(-0.5, \mathsf{fma}\left(\tan x, \tan x, 1\right), 0.16666666666666666 \cdot \left(\tan x \cdot \tan x\right)\right) - \mathsf{fma}\left(\tan x, \tan x, 1\right) \cdot \left(\tan x \cdot \tan x\right)\right) - -0.16666666666666666, -\varepsilon, \mathsf{fma}\left(\tan x, \tan x, 1\right) \cdot \tan x\right), \varepsilon, \mathsf{fma}\left(\tan x, \tan x, 1\right)\right) \cdot \varepsilon} \]
  5. Applied rewrites99.6%

    \[\leadsto \mathsf{fma}\left(\mathsf{fma}\left(\mathsf{fma}\left(0.16666666666666666, {\tan x}^{2}, \mathsf{fma}\left({\tan x}^{2}, -0.5, -0.5\right)\right) - \mathsf{fma}\left({\tan x}^{2}, {\tan x}^{2} - -1, -0.16666666666666666\right), -\varepsilon, \left({\tan x}^{2} - -1\right) \cdot \tan x\right), \varepsilon, {\tan x}^{2} - -1\right) \cdot \color{blue}{\varepsilon} \]
  6. Taylor expanded in x around 0

    \[\leadsto \mathsf{fma}\left(\mathsf{fma}\left({x}^{2} \cdot \left({x}^{2} \cdot \left(\frac{-248}{135} \cdot {x}^{2} - \frac{17}{9}\right) - \frac{4}{3}\right) - \frac{1}{3}, -\varepsilon, \left({\tan x}^{2} - -1\right) \cdot \tan x\right), \varepsilon, {\tan x}^{2} - -1\right) \cdot \varepsilon \]
  7. Applied rewrites99.3%

    \[\leadsto \mathsf{fma}\left(\mathsf{fma}\left({x}^{2} \cdot \left({x}^{2} \cdot \left(-1.837037037037037 \cdot {x}^{2} - 1.8888888888888888\right) - 1.3333333333333333\right) - 0.3333333333333333, -\varepsilon, \left({\tan x}^{2} - -1\right) \cdot \tan x\right), \varepsilon, {\tan x}^{2} - -1\right) \cdot \varepsilon \]
  8. Add Preprocessing

Alternative 6: 99.4% accurate, 0.4× speedup?

\[\begin{array}{l} \\ \begin{array}{l} t_0 := {\tan x}^{2} - -1\\ \mathsf{fma}\left(\mathsf{fma}\left({x}^{2} \cdot \left(-1.8888888888888888 \cdot {x}^{2} - 1.3333333333333333\right) - 0.3333333333333333, -\varepsilon, t\_0 \cdot \tan x\right), \varepsilon, t\_0\right) \cdot \varepsilon \end{array} \end{array} \]
(FPCore (x eps)
 :precision binary64
 (let* ((t_0 (- (pow (tan x) 2.0) -1.0)))
   (*
    (fma
     (fma
      (-
       (*
        (pow x 2.0)
        (- (* -1.8888888888888888 (pow x 2.0)) 1.3333333333333333))
       0.3333333333333333)
      (- eps)
      (* t_0 (tan x)))
     eps
     t_0)
    eps)))
double code(double x, double eps) {
	double t_0 = pow(tan(x), 2.0) - -1.0;
	return fma(fma(((pow(x, 2.0) * ((-1.8888888888888888 * pow(x, 2.0)) - 1.3333333333333333)) - 0.3333333333333333), -eps, (t_0 * tan(x))), eps, t_0) * eps;
}
function code(x, eps)
	t_0 = Float64((tan(x) ^ 2.0) - -1.0)
	return Float64(fma(fma(Float64(Float64((x ^ 2.0) * Float64(Float64(-1.8888888888888888 * (x ^ 2.0)) - 1.3333333333333333)) - 0.3333333333333333), Float64(-eps), Float64(t_0 * tan(x))), eps, t_0) * eps)
end
code[x_, eps_] := Block[{t$95$0 = N[(N[Power[N[Tan[x], $MachinePrecision], 2.0], $MachinePrecision] - -1.0), $MachinePrecision]}, N[(N[(N[(N[(N[(N[Power[x, 2.0], $MachinePrecision] * N[(N[(-1.8888888888888888 * N[Power[x, 2.0], $MachinePrecision]), $MachinePrecision] - 1.3333333333333333), $MachinePrecision]), $MachinePrecision] - 0.3333333333333333), $MachinePrecision] * (-eps) + N[(t$95$0 * N[Tan[x], $MachinePrecision]), $MachinePrecision]), $MachinePrecision] * eps + t$95$0), $MachinePrecision] * eps), $MachinePrecision]]
\begin{array}{l}

\\
\begin{array}{l}
t_0 := {\tan x}^{2} - -1\\
\mathsf{fma}\left(\mathsf{fma}\left({x}^{2} \cdot \left(-1.8888888888888888 \cdot {x}^{2} - 1.3333333333333333\right) - 0.3333333333333333, -\varepsilon, t\_0 \cdot \tan x\right), \varepsilon, t\_0\right) \cdot \varepsilon
\end{array}
\end{array}
Derivation
  1. Initial program 61.9%

    \[\tan \left(x + \varepsilon\right) - \tan x \]
  2. Taylor expanded in eps around 0

    \[\leadsto \color{blue}{\varepsilon \cdot \left(\left(1 + \varepsilon \cdot \left(-1 \cdot \left(\varepsilon \cdot \left(\frac{1}{6} + \left(-1 \cdot \frac{{\sin x}^{2} \cdot \left(1 - -1 \cdot \frac{{\sin x}^{2}}{{\cos x}^{2}}\right)}{{\cos x}^{2}} + \left(\frac{-1}{2} \cdot \left(1 - -1 \cdot \frac{{\sin x}^{2}}{{\cos x}^{2}}\right) + \frac{1}{6} \cdot \frac{{\sin x}^{2}}{{\cos x}^{2}}\right)\right)\right)\right) - -1 \cdot \frac{\sin x \cdot \left(1 - -1 \cdot \frac{{\sin x}^{2}}{{\cos x}^{2}}\right)}{\cos x}\right)\right) - -1 \cdot \frac{{\sin x}^{2}}{{\cos x}^{2}}\right)} \]
  3. Applied rewrites99.6%

    \[\leadsto \color{blue}{\varepsilon \cdot \left(\left(1 + \varepsilon \cdot \left(-1 \cdot \left(\varepsilon \cdot \left(0.16666666666666666 + \mathsf{fma}\left(-1, \frac{{\sin x}^{2} \cdot \left(1 - -1 \cdot \frac{{\sin x}^{2}}{{\cos x}^{2}}\right)}{{\cos x}^{2}}, \mathsf{fma}\left(-0.5, 1 - -1 \cdot \frac{{\sin x}^{2}}{{\cos x}^{2}}, 0.16666666666666666 \cdot \frac{{\sin x}^{2}}{{\cos x}^{2}}\right)\right)\right)\right) - -1 \cdot \frac{\sin x \cdot \left(1 - -1 \cdot \frac{{\sin x}^{2}}{{\cos x}^{2}}\right)}{\cos x}\right)\right) - -1 \cdot \frac{{\sin x}^{2}}{{\cos x}^{2}}\right)} \]
  4. Applied rewrites99.6%

    \[\leadsto \color{blue}{\mathsf{fma}\left(\mathsf{fma}\left(\left(\mathsf{fma}\left(-0.5, \mathsf{fma}\left(\tan x, \tan x, 1\right), 0.16666666666666666 \cdot \left(\tan x \cdot \tan x\right)\right) - \mathsf{fma}\left(\tan x, \tan x, 1\right) \cdot \left(\tan x \cdot \tan x\right)\right) - -0.16666666666666666, -\varepsilon, \mathsf{fma}\left(\tan x, \tan x, 1\right) \cdot \tan x\right), \varepsilon, \mathsf{fma}\left(\tan x, \tan x, 1\right)\right) \cdot \varepsilon} \]
  5. Applied rewrites99.6%

    \[\leadsto \mathsf{fma}\left(\mathsf{fma}\left(\mathsf{fma}\left(0.16666666666666666, {\tan x}^{2}, \mathsf{fma}\left({\tan x}^{2}, -0.5, -0.5\right)\right) - \mathsf{fma}\left({\tan x}^{2}, {\tan x}^{2} - -1, -0.16666666666666666\right), -\varepsilon, \left({\tan x}^{2} - -1\right) \cdot \tan x\right), \varepsilon, {\tan x}^{2} - -1\right) \cdot \color{blue}{\varepsilon} \]
  6. Taylor expanded in x around 0

    \[\leadsto \mathsf{fma}\left(\mathsf{fma}\left({x}^{2} \cdot \left(\frac{-17}{9} \cdot {x}^{2} - \frac{4}{3}\right) - \frac{1}{3}, -\varepsilon, \left({\tan x}^{2} - -1\right) \cdot \tan x\right), \varepsilon, {\tan x}^{2} - -1\right) \cdot \varepsilon \]
  7. Applied rewrites99.3%

    \[\leadsto \mathsf{fma}\left(\mathsf{fma}\left({x}^{2} \cdot \left(-1.8888888888888888 \cdot {x}^{2} - 1.3333333333333333\right) - 0.3333333333333333, -\varepsilon, \left({\tan x}^{2} - -1\right) \cdot \tan x\right), \varepsilon, {\tan x}^{2} - -1\right) \cdot \varepsilon \]
  8. Add Preprocessing

Alternative 7: 99.4% accurate, 0.4× speedup?

\[\begin{array}{l} \\ \begin{array}{l} t_0 := {\tan x}^{2} - -1\\ \mathsf{fma}\left(\mathsf{fma}\left(-1.3333333333333333 \cdot {x}^{2} - 0.3333333333333333, -\varepsilon, t\_0 \cdot \tan x\right), \varepsilon, t\_0\right) \cdot \varepsilon \end{array} \end{array} \]
(FPCore (x eps)
 :precision binary64
 (let* ((t_0 (- (pow (tan x) 2.0) -1.0)))
   (*
    (fma
     (fma
      (- (* -1.3333333333333333 (pow x 2.0)) 0.3333333333333333)
      (- eps)
      (* t_0 (tan x)))
     eps
     t_0)
    eps)))
double code(double x, double eps) {
	double t_0 = pow(tan(x), 2.0) - -1.0;
	return fma(fma(((-1.3333333333333333 * pow(x, 2.0)) - 0.3333333333333333), -eps, (t_0 * tan(x))), eps, t_0) * eps;
}
function code(x, eps)
	t_0 = Float64((tan(x) ^ 2.0) - -1.0)
	return Float64(fma(fma(Float64(Float64(-1.3333333333333333 * (x ^ 2.0)) - 0.3333333333333333), Float64(-eps), Float64(t_0 * tan(x))), eps, t_0) * eps)
end
code[x_, eps_] := Block[{t$95$0 = N[(N[Power[N[Tan[x], $MachinePrecision], 2.0], $MachinePrecision] - -1.0), $MachinePrecision]}, N[(N[(N[(N[(N[(-1.3333333333333333 * N[Power[x, 2.0], $MachinePrecision]), $MachinePrecision] - 0.3333333333333333), $MachinePrecision] * (-eps) + N[(t$95$0 * N[Tan[x], $MachinePrecision]), $MachinePrecision]), $MachinePrecision] * eps + t$95$0), $MachinePrecision] * eps), $MachinePrecision]]
\begin{array}{l}

\\
\begin{array}{l}
t_0 := {\tan x}^{2} - -1\\
\mathsf{fma}\left(\mathsf{fma}\left(-1.3333333333333333 \cdot {x}^{2} - 0.3333333333333333, -\varepsilon, t\_0 \cdot \tan x\right), \varepsilon, t\_0\right) \cdot \varepsilon
\end{array}
\end{array}
Derivation
  1. Initial program 61.9%

    \[\tan \left(x + \varepsilon\right) - \tan x \]
  2. Taylor expanded in eps around 0

    \[\leadsto \color{blue}{\varepsilon \cdot \left(\left(1 + \varepsilon \cdot \left(-1 \cdot \left(\varepsilon \cdot \left(\frac{1}{6} + \left(-1 \cdot \frac{{\sin x}^{2} \cdot \left(1 - -1 \cdot \frac{{\sin x}^{2}}{{\cos x}^{2}}\right)}{{\cos x}^{2}} + \left(\frac{-1}{2} \cdot \left(1 - -1 \cdot \frac{{\sin x}^{2}}{{\cos x}^{2}}\right) + \frac{1}{6} \cdot \frac{{\sin x}^{2}}{{\cos x}^{2}}\right)\right)\right)\right) - -1 \cdot \frac{\sin x \cdot \left(1 - -1 \cdot \frac{{\sin x}^{2}}{{\cos x}^{2}}\right)}{\cos x}\right)\right) - -1 \cdot \frac{{\sin x}^{2}}{{\cos x}^{2}}\right)} \]
  3. Applied rewrites99.6%

    \[\leadsto \color{blue}{\varepsilon \cdot \left(\left(1 + \varepsilon \cdot \left(-1 \cdot \left(\varepsilon \cdot \left(0.16666666666666666 + \mathsf{fma}\left(-1, \frac{{\sin x}^{2} \cdot \left(1 - -1 \cdot \frac{{\sin x}^{2}}{{\cos x}^{2}}\right)}{{\cos x}^{2}}, \mathsf{fma}\left(-0.5, 1 - -1 \cdot \frac{{\sin x}^{2}}{{\cos x}^{2}}, 0.16666666666666666 \cdot \frac{{\sin x}^{2}}{{\cos x}^{2}}\right)\right)\right)\right) - -1 \cdot \frac{\sin x \cdot \left(1 - -1 \cdot \frac{{\sin x}^{2}}{{\cos x}^{2}}\right)}{\cos x}\right)\right) - -1 \cdot \frac{{\sin x}^{2}}{{\cos x}^{2}}\right)} \]
  4. Applied rewrites99.6%

    \[\leadsto \color{blue}{\mathsf{fma}\left(\mathsf{fma}\left(\left(\mathsf{fma}\left(-0.5, \mathsf{fma}\left(\tan x, \tan x, 1\right), 0.16666666666666666 \cdot \left(\tan x \cdot \tan x\right)\right) - \mathsf{fma}\left(\tan x, \tan x, 1\right) \cdot \left(\tan x \cdot \tan x\right)\right) - -0.16666666666666666, -\varepsilon, \mathsf{fma}\left(\tan x, \tan x, 1\right) \cdot \tan x\right), \varepsilon, \mathsf{fma}\left(\tan x, \tan x, 1\right)\right) \cdot \varepsilon} \]
  5. Applied rewrites99.6%

    \[\leadsto \mathsf{fma}\left(\mathsf{fma}\left(\mathsf{fma}\left(0.16666666666666666, {\tan x}^{2}, \mathsf{fma}\left({\tan x}^{2}, -0.5, -0.5\right)\right) - \mathsf{fma}\left({\tan x}^{2}, {\tan x}^{2} - -1, -0.16666666666666666\right), -\varepsilon, \left({\tan x}^{2} - -1\right) \cdot \tan x\right), \varepsilon, {\tan x}^{2} - -1\right) \cdot \color{blue}{\varepsilon} \]
  6. Taylor expanded in x around 0

    \[\leadsto \mathsf{fma}\left(\mathsf{fma}\left(\frac{-4}{3} \cdot {x}^{2} - \frac{1}{3}, -\varepsilon, \left({\tan x}^{2} - -1\right) \cdot \tan x\right), \varepsilon, {\tan x}^{2} - -1\right) \cdot \varepsilon \]
  7. Applied rewrites99.4%

    \[\leadsto \mathsf{fma}\left(\mathsf{fma}\left(-1.3333333333333333 \cdot {x}^{2} - 0.3333333333333333, -\varepsilon, \left({\tan x}^{2} - -1\right) \cdot \tan x\right), \varepsilon, {\tan x}^{2} - -1\right) \cdot \varepsilon \]
  8. Add Preprocessing

Alternative 8: 99.4% accurate, 0.5× speedup?

\[\begin{array}{l} \\ \begin{array}{l} t_0 := {\tan x}^{2} - -1\\ \mathsf{fma}\left(\mathsf{fma}\left(-0.3333333333333333, -\varepsilon, t\_0 \cdot \tan x\right), \varepsilon, t\_0\right) \cdot \varepsilon \end{array} \end{array} \]
(FPCore (x eps)
 :precision binary64
 (let* ((t_0 (- (pow (tan x) 2.0) -1.0)))
   (* (fma (fma -0.3333333333333333 (- eps) (* t_0 (tan x))) eps t_0) eps)))
double code(double x, double eps) {
	double t_0 = pow(tan(x), 2.0) - -1.0;
	return fma(fma(-0.3333333333333333, -eps, (t_0 * tan(x))), eps, t_0) * eps;
}
function code(x, eps)
	t_0 = Float64((tan(x) ^ 2.0) - -1.0)
	return Float64(fma(fma(-0.3333333333333333, Float64(-eps), Float64(t_0 * tan(x))), eps, t_0) * eps)
end
code[x_, eps_] := Block[{t$95$0 = N[(N[Power[N[Tan[x], $MachinePrecision], 2.0], $MachinePrecision] - -1.0), $MachinePrecision]}, N[(N[(N[(-0.3333333333333333 * (-eps) + N[(t$95$0 * N[Tan[x], $MachinePrecision]), $MachinePrecision]), $MachinePrecision] * eps + t$95$0), $MachinePrecision] * eps), $MachinePrecision]]
\begin{array}{l}

\\
\begin{array}{l}
t_0 := {\tan x}^{2} - -1\\
\mathsf{fma}\left(\mathsf{fma}\left(-0.3333333333333333, -\varepsilon, t\_0 \cdot \tan x\right), \varepsilon, t\_0\right) \cdot \varepsilon
\end{array}
\end{array}
Derivation
  1. Initial program 61.9%

    \[\tan \left(x + \varepsilon\right) - \tan x \]
  2. Taylor expanded in eps around 0

    \[\leadsto \color{blue}{\varepsilon \cdot \left(\left(1 + \varepsilon \cdot \left(-1 \cdot \left(\varepsilon \cdot \left(\frac{1}{6} + \left(-1 \cdot \frac{{\sin x}^{2} \cdot \left(1 - -1 \cdot \frac{{\sin x}^{2}}{{\cos x}^{2}}\right)}{{\cos x}^{2}} + \left(\frac{-1}{2} \cdot \left(1 - -1 \cdot \frac{{\sin x}^{2}}{{\cos x}^{2}}\right) + \frac{1}{6} \cdot \frac{{\sin x}^{2}}{{\cos x}^{2}}\right)\right)\right)\right) - -1 \cdot \frac{\sin x \cdot \left(1 - -1 \cdot \frac{{\sin x}^{2}}{{\cos x}^{2}}\right)}{\cos x}\right)\right) - -1 \cdot \frac{{\sin x}^{2}}{{\cos x}^{2}}\right)} \]
  3. Applied rewrites99.6%

    \[\leadsto \color{blue}{\varepsilon \cdot \left(\left(1 + \varepsilon \cdot \left(-1 \cdot \left(\varepsilon \cdot \left(0.16666666666666666 + \mathsf{fma}\left(-1, \frac{{\sin x}^{2} \cdot \left(1 - -1 \cdot \frac{{\sin x}^{2}}{{\cos x}^{2}}\right)}{{\cos x}^{2}}, \mathsf{fma}\left(-0.5, 1 - -1 \cdot \frac{{\sin x}^{2}}{{\cos x}^{2}}, 0.16666666666666666 \cdot \frac{{\sin x}^{2}}{{\cos x}^{2}}\right)\right)\right)\right) - -1 \cdot \frac{\sin x \cdot \left(1 - -1 \cdot \frac{{\sin x}^{2}}{{\cos x}^{2}}\right)}{\cos x}\right)\right) - -1 \cdot \frac{{\sin x}^{2}}{{\cos x}^{2}}\right)} \]
  4. Applied rewrites99.6%

    \[\leadsto \color{blue}{\mathsf{fma}\left(\mathsf{fma}\left(\left(\mathsf{fma}\left(-0.5, \mathsf{fma}\left(\tan x, \tan x, 1\right), 0.16666666666666666 \cdot \left(\tan x \cdot \tan x\right)\right) - \mathsf{fma}\left(\tan x, \tan x, 1\right) \cdot \left(\tan x \cdot \tan x\right)\right) - -0.16666666666666666, -\varepsilon, \mathsf{fma}\left(\tan x, \tan x, 1\right) \cdot \tan x\right), \varepsilon, \mathsf{fma}\left(\tan x, \tan x, 1\right)\right) \cdot \varepsilon} \]
  5. Applied rewrites99.6%

    \[\leadsto \mathsf{fma}\left(\mathsf{fma}\left(\mathsf{fma}\left(0.16666666666666666, {\tan x}^{2}, \mathsf{fma}\left({\tan x}^{2}, -0.5, -0.5\right)\right) - \mathsf{fma}\left({\tan x}^{2}, {\tan x}^{2} - -1, -0.16666666666666666\right), -\varepsilon, \left({\tan x}^{2} - -1\right) \cdot \tan x\right), \varepsilon, {\tan x}^{2} - -1\right) \cdot \color{blue}{\varepsilon} \]
  6. Taylor expanded in x around 0

    \[\leadsto \mathsf{fma}\left(\mathsf{fma}\left(\frac{-1}{3}, -\varepsilon, \left({\tan x}^{2} - -1\right) \cdot \tan x\right), \varepsilon, {\tan x}^{2} - -1\right) \cdot \varepsilon \]
  7. Applied rewrites99.5%

    \[\leadsto \mathsf{fma}\left(\mathsf{fma}\left(-0.3333333333333333, -\varepsilon, \left({\tan x}^{2} - -1\right) \cdot \tan x\right), \varepsilon, {\tan x}^{2} - -1\right) \cdot \varepsilon \]
  8. Add Preprocessing

Alternative 9: 99.3% accurate, 0.5× speedup?

\[\begin{array}{l} \\ \mathsf{fma}\left(\tan x \cdot \mathsf{fma}\left({\tan x}^{2} - -1, \varepsilon, \tan x\right), \varepsilon, 1 \cdot \varepsilon\right) \end{array} \]
(FPCore (x eps)
 :precision binary64
 (fma
  (* (tan x) (fma (- (pow (tan x) 2.0) -1.0) eps (tan x)))
  eps
  (* 1.0 eps)))
double code(double x, double eps) {
	return fma((tan(x) * fma((pow(tan(x), 2.0) - -1.0), eps, tan(x))), eps, (1.0 * eps));
}
function code(x, eps)
	return fma(Float64(tan(x) * fma(Float64((tan(x) ^ 2.0) - -1.0), eps, tan(x))), eps, Float64(1.0 * eps))
end
code[x_, eps_] := N[(N[(N[Tan[x], $MachinePrecision] * N[(N[(N[Power[N[Tan[x], $MachinePrecision], 2.0], $MachinePrecision] - -1.0), $MachinePrecision] * eps + N[Tan[x], $MachinePrecision]), $MachinePrecision]), $MachinePrecision] * eps + N[(1.0 * eps), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}

\\
\mathsf{fma}\left(\tan x \cdot \mathsf{fma}\left({\tan x}^{2} - -1, \varepsilon, \tan x\right), \varepsilon, 1 \cdot \varepsilon\right)
\end{array}
Derivation
  1. Initial program 61.9%

    \[\tan \left(x + \varepsilon\right) - \tan x \]
  2. Taylor expanded in eps around 0

    \[\leadsto \color{blue}{\varepsilon \cdot \left(\left(1 + \frac{\varepsilon \cdot \left(\sin x \cdot \left(1 - -1 \cdot \frac{{\sin x}^{2}}{{\cos x}^{2}}\right)\right)}{\cos x}\right) - -1 \cdot \frac{{\sin x}^{2}}{{\cos x}^{2}}\right)} \]
  3. Applied rewrites99.4%

    \[\leadsto \color{blue}{\varepsilon \cdot \left(\left(1 + \frac{\varepsilon \cdot \left(\sin x \cdot \left(1 - -1 \cdot \frac{{\sin x}^{2}}{{\cos x}^{2}}\right)\right)}{\cos x}\right) - -1 \cdot \frac{{\sin x}^{2}}{{\cos x}^{2}}\right)} \]
  4. Applied rewrites99.4%

    \[\leadsto \varepsilon \cdot \mathsf{fma}\left(\varepsilon, \color{blue}{\mathsf{fma}\left(\tan x, \tan x, 1\right) \cdot \tan x}, \mathsf{fma}\left(\tan x, \tan x, 1\right)\right) \]
  5. Applied rewrites99.4%

    \[\leadsto \mathsf{fma}\left(\tan x \cdot \mathsf{fma}\left({\tan x}^{2} - -1, \varepsilon, \tan x\right), \color{blue}{\varepsilon}, 1 \cdot \varepsilon\right) \]
  6. Add Preprocessing

Alternative 10: 99.3% accurate, 0.6× speedup?

\[\begin{array}{l} \\ \mathsf{fma}\left(\tan x, \mathsf{fma}\left({\tan x}^{2} - -1, \varepsilon, \tan x\right), 1\right) \cdot \varepsilon \end{array} \]
(FPCore (x eps)
 :precision binary64
 (* (fma (tan x) (fma (- (pow (tan x) 2.0) -1.0) eps (tan x)) 1.0) eps))
double code(double x, double eps) {
	return fma(tan(x), fma((pow(tan(x), 2.0) - -1.0), eps, tan(x)), 1.0) * eps;
}
function code(x, eps)
	return Float64(fma(tan(x), fma(Float64((tan(x) ^ 2.0) - -1.0), eps, tan(x)), 1.0) * eps)
end
code[x_, eps_] := N[(N[(N[Tan[x], $MachinePrecision] * N[(N[(N[Power[N[Tan[x], $MachinePrecision], 2.0], $MachinePrecision] - -1.0), $MachinePrecision] * eps + N[Tan[x], $MachinePrecision]), $MachinePrecision] + 1.0), $MachinePrecision] * eps), $MachinePrecision]
\begin{array}{l}

\\
\mathsf{fma}\left(\tan x, \mathsf{fma}\left({\tan x}^{2} - -1, \varepsilon, \tan x\right), 1\right) \cdot \varepsilon
\end{array}
Derivation
  1. Initial program 61.9%

    \[\tan \left(x + \varepsilon\right) - \tan x \]
  2. Taylor expanded in eps around 0

    \[\leadsto \color{blue}{\varepsilon \cdot \left(\left(1 + \frac{\varepsilon \cdot \left(\sin x \cdot \left(1 - -1 \cdot \frac{{\sin x}^{2}}{{\cos x}^{2}}\right)\right)}{\cos x}\right) - -1 \cdot \frac{{\sin x}^{2}}{{\cos x}^{2}}\right)} \]
  3. Applied rewrites99.4%

    \[\leadsto \color{blue}{\varepsilon \cdot \left(\left(1 + \frac{\varepsilon \cdot \left(\sin x \cdot \left(1 - -1 \cdot \frac{{\sin x}^{2}}{{\cos x}^{2}}\right)\right)}{\cos x}\right) - -1 \cdot \frac{{\sin x}^{2}}{{\cos x}^{2}}\right)} \]
  4. Applied rewrites99.4%

    \[\leadsto \varepsilon \cdot \mathsf{fma}\left(\varepsilon, \color{blue}{\mathsf{fma}\left(\tan x, \tan x, 1\right) \cdot \tan x}, \mathsf{fma}\left(\tan x, \tan x, 1\right)\right) \]
  5. Applied rewrites99.4%

    \[\leadsto \mathsf{fma}\left(\tan x, \mathsf{fma}\left({\tan x}^{2} - -1, \varepsilon, \tan x\right), 1\right) \cdot \color{blue}{\varepsilon} \]
  6. Add Preprocessing

Alternative 11: 99.2% accurate, 1.1× speedup?

\[\begin{array}{l} \\ \mathsf{fma}\left(x + 0.3333333333333333 \cdot \varepsilon, \varepsilon, {\tan x}^{2} - -1\right) \cdot \varepsilon \end{array} \]
(FPCore (x eps)
 :precision binary64
 (* (fma (+ x (* 0.3333333333333333 eps)) eps (- (pow (tan x) 2.0) -1.0)) eps))
double code(double x, double eps) {
	return fma((x + (0.3333333333333333 * eps)), eps, (pow(tan(x), 2.0) - -1.0)) * eps;
}
function code(x, eps)
	return Float64(fma(Float64(x + Float64(0.3333333333333333 * eps)), eps, Float64((tan(x) ^ 2.0) - -1.0)) * eps)
end
code[x_, eps_] := N[(N[(N[(x + N[(0.3333333333333333 * eps), $MachinePrecision]), $MachinePrecision] * eps + N[(N[Power[N[Tan[x], $MachinePrecision], 2.0], $MachinePrecision] - -1.0), $MachinePrecision]), $MachinePrecision] * eps), $MachinePrecision]
\begin{array}{l}

\\
\mathsf{fma}\left(x + 0.3333333333333333 \cdot \varepsilon, \varepsilon, {\tan x}^{2} - -1\right) \cdot \varepsilon
\end{array}
Derivation
  1. Initial program 61.9%

    \[\tan \left(x + \varepsilon\right) - \tan x \]
  2. Taylor expanded in eps around 0

    \[\leadsto \color{blue}{\varepsilon \cdot \left(\left(1 + \varepsilon \cdot \left(-1 \cdot \left(\varepsilon \cdot \left(\frac{1}{6} + \left(-1 \cdot \frac{{\sin x}^{2} \cdot \left(1 - -1 \cdot \frac{{\sin x}^{2}}{{\cos x}^{2}}\right)}{{\cos x}^{2}} + \left(\frac{-1}{2} \cdot \left(1 - -1 \cdot \frac{{\sin x}^{2}}{{\cos x}^{2}}\right) + \frac{1}{6} \cdot \frac{{\sin x}^{2}}{{\cos x}^{2}}\right)\right)\right)\right) - -1 \cdot \frac{\sin x \cdot \left(1 - -1 \cdot \frac{{\sin x}^{2}}{{\cos x}^{2}}\right)}{\cos x}\right)\right) - -1 \cdot \frac{{\sin x}^{2}}{{\cos x}^{2}}\right)} \]
  3. Applied rewrites99.6%

    \[\leadsto \color{blue}{\varepsilon \cdot \left(\left(1 + \varepsilon \cdot \left(-1 \cdot \left(\varepsilon \cdot \left(0.16666666666666666 + \mathsf{fma}\left(-1, \frac{{\sin x}^{2} \cdot \left(1 - -1 \cdot \frac{{\sin x}^{2}}{{\cos x}^{2}}\right)}{{\cos x}^{2}}, \mathsf{fma}\left(-0.5, 1 - -1 \cdot \frac{{\sin x}^{2}}{{\cos x}^{2}}, 0.16666666666666666 \cdot \frac{{\sin x}^{2}}{{\cos x}^{2}}\right)\right)\right)\right) - -1 \cdot \frac{\sin x \cdot \left(1 - -1 \cdot \frac{{\sin x}^{2}}{{\cos x}^{2}}\right)}{\cos x}\right)\right) - -1 \cdot \frac{{\sin x}^{2}}{{\cos x}^{2}}\right)} \]
  4. Applied rewrites99.6%

    \[\leadsto \color{blue}{\mathsf{fma}\left(\mathsf{fma}\left(\left(\mathsf{fma}\left(-0.5, \mathsf{fma}\left(\tan x, \tan x, 1\right), 0.16666666666666666 \cdot \left(\tan x \cdot \tan x\right)\right) - \mathsf{fma}\left(\tan x, \tan x, 1\right) \cdot \left(\tan x \cdot \tan x\right)\right) - -0.16666666666666666, -\varepsilon, \mathsf{fma}\left(\tan x, \tan x, 1\right) \cdot \tan x\right), \varepsilon, \mathsf{fma}\left(\tan x, \tan x, 1\right)\right) \cdot \varepsilon} \]
  5. Applied rewrites99.6%

    \[\leadsto \mathsf{fma}\left(\mathsf{fma}\left(\mathsf{fma}\left(0.16666666666666666, {\tan x}^{2}, \mathsf{fma}\left({\tan x}^{2}, -0.5, -0.5\right)\right) - \mathsf{fma}\left({\tan x}^{2}, {\tan x}^{2} - -1, -0.16666666666666666\right), -\varepsilon, \left({\tan x}^{2} - -1\right) \cdot \tan x\right), \varepsilon, {\tan x}^{2} - -1\right) \cdot \color{blue}{\varepsilon} \]
  6. Taylor expanded in x around 0

    \[\leadsto \mathsf{fma}\left(x + \frac{1}{3} \cdot \varepsilon, \varepsilon, {\tan x}^{2} - -1\right) \cdot \varepsilon \]
  7. Applied rewrites99.2%

    \[\leadsto \mathsf{fma}\left(x + 0.3333333333333333 \cdot \varepsilon, \varepsilon, {\tan x}^{2} - -1\right) \cdot \varepsilon \]
  8. Add Preprocessing

Alternative 12: 99.1% accurate, 1.3× speedup?

\[\begin{array}{l} \\ \left({\tan x}^{2} - -1\right) \cdot \varepsilon \end{array} \]
(FPCore (x eps) :precision binary64 (* (- (pow (tan x) 2.0) -1.0) eps))
double code(double x, double eps) {
	return (pow(tan(x), 2.0) - -1.0) * eps;
}
module fmin_fmax_functions
    implicit none
    private
    public fmax
    public fmin

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

real(8) function code(x, eps)
use fmin_fmax_functions
    real(8), intent (in) :: x
    real(8), intent (in) :: eps
    code = ((tan(x) ** 2.0d0) - (-1.0d0)) * eps
end function
public static double code(double x, double eps) {
	return (Math.pow(Math.tan(x), 2.0) - -1.0) * eps;
}
def code(x, eps):
	return (math.pow(math.tan(x), 2.0) - -1.0) * eps
function code(x, eps)
	return Float64(Float64((tan(x) ^ 2.0) - -1.0) * eps)
end
function tmp = code(x, eps)
	tmp = ((tan(x) ^ 2.0) - -1.0) * eps;
end
code[x_, eps_] := N[(N[(N[Power[N[Tan[x], $MachinePrecision], 2.0], $MachinePrecision] - -1.0), $MachinePrecision] * eps), $MachinePrecision]
\begin{array}{l}

\\
\left({\tan x}^{2} - -1\right) \cdot \varepsilon
\end{array}
Derivation
  1. Initial program 61.9%

    \[\tan \left(x + \varepsilon\right) - \tan x \]
  2. Taylor expanded in eps around 0

    \[\leadsto \color{blue}{\varepsilon \cdot \left(1 - -1 \cdot \frac{{\sin x}^{2}}{{\cos x}^{2}}\right)} \]
  3. Applied rewrites99.1%

    \[\leadsto \color{blue}{\varepsilon \cdot \left(1 - -1 \cdot \frac{{\sin x}^{2}}{{\cos x}^{2}}\right)} \]
  4. Applied rewrites99.1%

    \[\leadsto \mathsf{fma}\left(\tan x, \tan x, 1\right) \cdot \color{blue}{\varepsilon} \]
  5. Applied rewrites99.1%

    \[\leadsto \left({\tan x}^{2} - -1\right) \cdot \color{blue}{\varepsilon} \]
  6. Add Preprocessing

Alternative 13: 98.4% accurate, 3.2× speedup?

\[\begin{array}{l} \\ \varepsilon \cdot \left(1 + x \cdot \left(\varepsilon + x \cdot \left(1 + 1.3333333333333333 \cdot \left(\varepsilon \cdot x\right)\right)\right)\right) \end{array} \]
(FPCore (x eps)
 :precision binary64
 (* eps (+ 1.0 (* x (+ eps (* x (+ 1.0 (* 1.3333333333333333 (* eps x)))))))))
double code(double x, double eps) {
	return eps * (1.0 + (x * (eps + (x * (1.0 + (1.3333333333333333 * (eps * x)))))));
}
module fmin_fmax_functions
    implicit none
    private
    public fmax
    public fmin

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

real(8) function code(x, eps)
use fmin_fmax_functions
    real(8), intent (in) :: x
    real(8), intent (in) :: eps
    code = eps * (1.0d0 + (x * (eps + (x * (1.0d0 + (1.3333333333333333d0 * (eps * x)))))))
end function
public static double code(double x, double eps) {
	return eps * (1.0 + (x * (eps + (x * (1.0 + (1.3333333333333333 * (eps * x)))))));
}
def code(x, eps):
	return eps * (1.0 + (x * (eps + (x * (1.0 + (1.3333333333333333 * (eps * x)))))))
function code(x, eps)
	return Float64(eps * Float64(1.0 + Float64(x * Float64(eps + Float64(x * Float64(1.0 + Float64(1.3333333333333333 * Float64(eps * x))))))))
end
function tmp = code(x, eps)
	tmp = eps * (1.0 + (x * (eps + (x * (1.0 + (1.3333333333333333 * (eps * x)))))));
end
code[x_, eps_] := N[(eps * N[(1.0 + N[(x * N[(eps + N[(x * N[(1.0 + N[(1.3333333333333333 * N[(eps * x), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}

\\
\varepsilon \cdot \left(1 + x \cdot \left(\varepsilon + x \cdot \left(1 + 1.3333333333333333 \cdot \left(\varepsilon \cdot x\right)\right)\right)\right)
\end{array}
Derivation
  1. Initial program 61.9%

    \[\tan \left(x + \varepsilon\right) - \tan x \]
  2. Taylor expanded in eps around 0

    \[\leadsto \color{blue}{\varepsilon \cdot \left(\left(1 + \frac{\varepsilon \cdot \left(\sin x \cdot \left(1 - -1 \cdot \frac{{\sin x}^{2}}{{\cos x}^{2}}\right)\right)}{\cos x}\right) - -1 \cdot \frac{{\sin x}^{2}}{{\cos x}^{2}}\right)} \]
  3. Applied rewrites99.4%

    \[\leadsto \color{blue}{\varepsilon \cdot \left(\left(1 + \frac{\varepsilon \cdot \left(\sin x \cdot \left(1 - -1 \cdot \frac{{\sin x}^{2}}{{\cos x}^{2}}\right)\right)}{\cos x}\right) - -1 \cdot \frac{{\sin x}^{2}}{{\cos x}^{2}}\right)} \]
  4. Applied rewrites99.4%

    \[\leadsto \varepsilon \cdot \mathsf{fma}\left(\varepsilon, \color{blue}{\mathsf{fma}\left(\tan x, \tan x, 1\right) \cdot \tan x}, \mathsf{fma}\left(\tan x, \tan x, 1\right)\right) \]
  5. Taylor expanded in x around 0

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

    \[\leadsto \varepsilon \cdot \left(1 + \color{blue}{x \cdot \left(\varepsilon + x \cdot \left(1 + 1.3333333333333333 \cdot \left(\varepsilon \cdot x\right)\right)\right)}\right) \]
  7. Add Preprocessing

Alternative 14: 98.4% accurate, 3.5× speedup?

\[\begin{array}{l} \\ \varepsilon \cdot \mathsf{fma}\left(\varepsilon, \mathsf{fma}\left(x, x, 1\right) \cdot x, \mathsf{fma}\left(x, x, 1\right)\right) \end{array} \]
(FPCore (x eps)
 :precision binary64
 (* eps (fma eps (* (fma x x 1.0) x) (fma x x 1.0))))
double code(double x, double eps) {
	return eps * fma(eps, (fma(x, x, 1.0) * x), fma(x, x, 1.0));
}
function code(x, eps)
	return Float64(eps * fma(eps, Float64(fma(x, x, 1.0) * x), fma(x, x, 1.0)))
end
code[x_, eps_] := N[(eps * N[(eps * N[(N[(x * x + 1.0), $MachinePrecision] * x), $MachinePrecision] + N[(x * x + 1.0), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}

\\
\varepsilon \cdot \mathsf{fma}\left(\varepsilon, \mathsf{fma}\left(x, x, 1\right) \cdot x, \mathsf{fma}\left(x, x, 1\right)\right)
\end{array}
Derivation
  1. Initial program 61.9%

    \[\tan \left(x + \varepsilon\right) - \tan x \]
  2. Taylor expanded in eps around 0

    \[\leadsto \color{blue}{\varepsilon \cdot \left(\left(1 + \frac{\varepsilon \cdot \left(\sin x \cdot \left(1 - -1 \cdot \frac{{\sin x}^{2}}{{\cos x}^{2}}\right)\right)}{\cos x}\right) - -1 \cdot \frac{{\sin x}^{2}}{{\cos x}^{2}}\right)} \]
  3. Applied rewrites99.4%

    \[\leadsto \color{blue}{\varepsilon \cdot \left(\left(1 + \frac{\varepsilon \cdot \left(\sin x \cdot \left(1 - -1 \cdot \frac{{\sin x}^{2}}{{\cos x}^{2}}\right)\right)}{\cos x}\right) - -1 \cdot \frac{{\sin x}^{2}}{{\cos x}^{2}}\right)} \]
  4. Applied rewrites99.4%

    \[\leadsto \varepsilon \cdot \mathsf{fma}\left(\varepsilon, \color{blue}{\mathsf{fma}\left(\tan x, \tan x, 1\right) \cdot \tan x}, \mathsf{fma}\left(\tan x, \tan x, 1\right)\right) \]
  5. Taylor expanded in x around 0

    \[\leadsto \varepsilon \cdot \mathsf{fma}\left(\varepsilon, \mathsf{fma}\left(x, \tan x, 1\right) \cdot \tan x, \mathsf{fma}\left(\tan x, \tan x, 1\right)\right) \]
  6. Applied rewrites99.1%

    \[\leadsto \varepsilon \cdot \mathsf{fma}\left(\varepsilon, \mathsf{fma}\left(x, \tan x, 1\right) \cdot \tan x, \mathsf{fma}\left(\tan x, \tan x, 1\right)\right) \]
  7. Taylor expanded in x around 0

    \[\leadsto \varepsilon \cdot \mathsf{fma}\left(\varepsilon, \mathsf{fma}\left(x, x, 1\right) \cdot \tan x, \mathsf{fma}\left(\tan x, \tan x, 1\right)\right) \]
  8. Applied rewrites99.0%

    \[\leadsto \varepsilon \cdot \mathsf{fma}\left(\varepsilon, \mathsf{fma}\left(x, x, 1\right) \cdot \tan x, \mathsf{fma}\left(\tan x, \tan x, 1\right)\right) \]
  9. Taylor expanded in x around 0

    \[\leadsto \varepsilon \cdot \mathsf{fma}\left(\varepsilon, \mathsf{fma}\left(x, x, 1\right) \cdot x, \mathsf{fma}\left(\tan x, \tan x, 1\right)\right) \]
  10. Applied rewrites99.0%

    \[\leadsto \varepsilon \cdot \mathsf{fma}\left(\varepsilon, \mathsf{fma}\left(x, x, 1\right) \cdot x, \mathsf{fma}\left(\tan x, \tan x, 1\right)\right) \]
  11. Taylor expanded in x around 0

    \[\leadsto \varepsilon \cdot \mathsf{fma}\left(\varepsilon, \mathsf{fma}\left(x, x, 1\right) \cdot x, \mathsf{fma}\left(x, \tan x, 1\right)\right) \]
  12. Applied rewrites98.4%

    \[\leadsto \varepsilon \cdot \mathsf{fma}\left(\varepsilon, \mathsf{fma}\left(x, x, 1\right) \cdot x, \mathsf{fma}\left(x, \tan x, 1\right)\right) \]
  13. Taylor expanded in x around 0

    \[\leadsto \varepsilon \cdot \mathsf{fma}\left(\varepsilon, \mathsf{fma}\left(x, x, 1\right) \cdot x, \mathsf{fma}\left(x, x, 1\right)\right) \]
  14. Applied rewrites98.4%

    \[\leadsto \varepsilon \cdot \mathsf{fma}\left(\varepsilon, \mathsf{fma}\left(x, x, 1\right) \cdot x, \mathsf{fma}\left(x, x, 1\right)\right) \]
  15. Add Preprocessing

Alternative 15: 98.4% accurate, 6.2× speedup?

\[\begin{array}{l} \\ \varepsilon \cdot \left(1 + x \cdot \left(\varepsilon + x\right)\right) \end{array} \]
(FPCore (x eps) :precision binary64 (* eps (+ 1.0 (* x (+ eps x)))))
double code(double x, double eps) {
	return eps * (1.0 + (x * (eps + x)));
}
module fmin_fmax_functions
    implicit none
    private
    public fmax
    public fmin

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

real(8) function code(x, eps)
use fmin_fmax_functions
    real(8), intent (in) :: x
    real(8), intent (in) :: eps
    code = eps * (1.0d0 + (x * (eps + x)))
end function
public static double code(double x, double eps) {
	return eps * (1.0 + (x * (eps + x)));
}
def code(x, eps):
	return eps * (1.0 + (x * (eps + x)))
function code(x, eps)
	return Float64(eps * Float64(1.0 + Float64(x * Float64(eps + x))))
end
function tmp = code(x, eps)
	tmp = eps * (1.0 + (x * (eps + x)));
end
code[x_, eps_] := N[(eps * N[(1.0 + N[(x * N[(eps + x), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}

\\
\varepsilon \cdot \left(1 + x \cdot \left(\varepsilon + x\right)\right)
\end{array}
Derivation
  1. Initial program 61.9%

    \[\tan \left(x + \varepsilon\right) - \tan x \]
  2. Taylor expanded in eps around 0

    \[\leadsto \color{blue}{\varepsilon \cdot \left(\left(1 + \frac{\varepsilon \cdot \left(\sin x \cdot \left(1 - -1 \cdot \frac{{\sin x}^{2}}{{\cos x}^{2}}\right)\right)}{\cos x}\right) - -1 \cdot \frac{{\sin x}^{2}}{{\cos x}^{2}}\right)} \]
  3. Applied rewrites99.4%

    \[\leadsto \color{blue}{\varepsilon \cdot \left(\left(1 + \frac{\varepsilon \cdot \left(\sin x \cdot \left(1 - -1 \cdot \frac{{\sin x}^{2}}{{\cos x}^{2}}\right)\right)}{\cos x}\right) - -1 \cdot \frac{{\sin x}^{2}}{{\cos x}^{2}}\right)} \]
  4. Taylor expanded in x around 0

    \[\leadsto \varepsilon \cdot \left(1 + \color{blue}{x \cdot \left(\varepsilon + x\right)}\right) \]
  5. Applied rewrites98.4%

    \[\leadsto \varepsilon \cdot \left(1 + \color{blue}{x \cdot \left(\varepsilon + x\right)}\right) \]
  6. Add Preprocessing

Alternative 16: 98.4% accurate, 8.6× speedup?

\[\begin{array}{l} \\ \mathsf{fma}\left(x, x, 1\right) \cdot \varepsilon \end{array} \]
(FPCore (x eps) :precision binary64 (* (fma x x 1.0) eps))
double code(double x, double eps) {
	return fma(x, x, 1.0) * eps;
}
function code(x, eps)
	return Float64(fma(x, x, 1.0) * eps)
end
code[x_, eps_] := N[(N[(x * x + 1.0), $MachinePrecision] * eps), $MachinePrecision]
\begin{array}{l}

\\
\mathsf{fma}\left(x, x, 1\right) \cdot \varepsilon
\end{array}
Derivation
  1. Initial program 61.9%

    \[\tan \left(x + \varepsilon\right) - \tan x \]
  2. Taylor expanded in eps around 0

    \[\leadsto \color{blue}{\varepsilon \cdot \left(1 - -1 \cdot \frac{{\sin x}^{2}}{{\cos x}^{2}}\right)} \]
  3. Applied rewrites99.1%

    \[\leadsto \color{blue}{\varepsilon \cdot \left(1 - -1 \cdot \frac{{\sin x}^{2}}{{\cos x}^{2}}\right)} \]
  4. Applied rewrites99.1%

    \[\leadsto \mathsf{fma}\left(\tan x, \tan x, 1\right) \cdot \color{blue}{\varepsilon} \]
  5. Taylor expanded in x around 0

    \[\leadsto \mathsf{fma}\left(x, \tan x, 1\right) \cdot \varepsilon \]
  6. Applied rewrites98.3%

    \[\leadsto \mathsf{fma}\left(x, \tan x, 1\right) \cdot \varepsilon \]
  7. Taylor expanded in x around 0

    \[\leadsto \mathsf{fma}\left(x, x, 1\right) \cdot \varepsilon \]
  8. Applied rewrites98.4%

    \[\leadsto \mathsf{fma}\left(x, x, 1\right) \cdot \varepsilon \]
  9. Add Preprocessing

Alternative 17: 97.9% accurate, 76.4× speedup?

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

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

real(8) function code(x, eps)
use fmin_fmax_functions
    real(8), intent (in) :: x
    real(8), intent (in) :: eps
    code = eps
end function
public static double code(double x, double eps) {
	return eps;
}
def code(x, eps):
	return eps
function code(x, eps)
	return eps
end
function tmp = code(x, eps)
	tmp = eps;
end
code[x_, eps_] := eps
\begin{array}{l}

\\
\varepsilon
\end{array}
Derivation
  1. Initial program 61.9%

    \[\tan \left(x + \varepsilon\right) - \tan x \]
  2. Taylor expanded in eps around 0

    \[\leadsto \color{blue}{\varepsilon \cdot \left(1 - -1 \cdot \frac{{\sin x}^{2}}{{\cos x}^{2}}\right)} \]
  3. Applied rewrites99.1%

    \[\leadsto \color{blue}{\varepsilon \cdot \left(1 - -1 \cdot \frac{{\sin x}^{2}}{{\cos x}^{2}}\right)} \]
  4. Taylor expanded in x around 0

    \[\leadsto \varepsilon \cdot 1 \]
  5. Applied rewrites97.9%

    \[\leadsto \varepsilon \cdot 1 \]
  6. Taylor expanded in x around 0

    \[\leadsto \varepsilon \]
  7. Applied rewrites97.9%

    \[\leadsto \varepsilon \]
  8. Add Preprocessing

Developer Target 1: 99.9% accurate, 0.7× speedup?

\[\begin{array}{l} \\ \frac{\sin \varepsilon}{\cos x \cdot \cos \left(x + \varepsilon\right)} \end{array} \]
(FPCore (x eps) :precision binary64 (/ (sin eps) (* (cos x) (cos (+ x eps)))))
double code(double x, double eps) {
	return sin(eps) / (cos(x) * cos((x + eps)));
}
module fmin_fmax_functions
    implicit none
    private
    public fmax
    public fmin

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

real(8) function code(x, eps)
use fmin_fmax_functions
    real(8), intent (in) :: x
    real(8), intent (in) :: eps
    code = sin(eps) / (cos(x) * cos((x + eps)))
end function
public static double code(double x, double eps) {
	return Math.sin(eps) / (Math.cos(x) * Math.cos((x + eps)));
}
def code(x, eps):
	return math.sin(eps) / (math.cos(x) * math.cos((x + eps)))
function code(x, eps)
	return Float64(sin(eps) / Float64(cos(x) * cos(Float64(x + eps))))
end
function tmp = code(x, eps)
	tmp = sin(eps) / (cos(x) * cos((x + eps)));
end
code[x_, eps_] := N[(N[Sin[eps], $MachinePrecision] / N[(N[Cos[x], $MachinePrecision] * N[Cos[N[(x + eps), $MachinePrecision]], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}

\\
\frac{\sin \varepsilon}{\cos x \cdot \cos \left(x + \varepsilon\right)}
\end{array}

Developer Target 2: 62.0% accurate, 0.4× speedup?

\[\begin{array}{l} \\ \frac{\tan x + \tan \varepsilon}{1 - \tan x \cdot \tan \varepsilon} - \tan x \end{array} \]
(FPCore (x eps)
 :precision binary64
 (- (/ (+ (tan x) (tan eps)) (- 1.0 (* (tan x) (tan eps)))) (tan x)))
double code(double x, double eps) {
	return ((tan(x) + tan(eps)) / (1.0 - (tan(x) * tan(eps)))) - tan(x);
}
module fmin_fmax_functions
    implicit none
    private
    public fmax
    public fmin

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

real(8) function code(x, eps)
use fmin_fmax_functions
    real(8), intent (in) :: x
    real(8), intent (in) :: eps
    code = ((tan(x) + tan(eps)) / (1.0d0 - (tan(x) * tan(eps)))) - tan(x)
end function
public static double code(double x, double eps) {
	return ((Math.tan(x) + Math.tan(eps)) / (1.0 - (Math.tan(x) * Math.tan(eps)))) - Math.tan(x);
}
def code(x, eps):
	return ((math.tan(x) + math.tan(eps)) / (1.0 - (math.tan(x) * math.tan(eps)))) - math.tan(x)
function code(x, eps)
	return Float64(Float64(Float64(tan(x) + tan(eps)) / Float64(1.0 - Float64(tan(x) * tan(eps)))) - tan(x))
end
function tmp = code(x, eps)
	tmp = ((tan(x) + tan(eps)) / (1.0 - (tan(x) * tan(eps)))) - tan(x);
end
code[x_, eps_] := N[(N[(N[(N[Tan[x], $MachinePrecision] + N[Tan[eps], $MachinePrecision]), $MachinePrecision] / N[(1.0 - N[(N[Tan[x], $MachinePrecision] * N[Tan[eps], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision] - N[Tan[x], $MachinePrecision]), $MachinePrecision]
\begin{array}{l}

\\
\frac{\tan x + \tan \varepsilon}{1 - \tan x \cdot \tan \varepsilon} - \tan x
\end{array}

Developer Target 3: 99.1% accurate, 1.0× speedup?

\[\begin{array}{l} \\ \varepsilon + \left(\varepsilon \cdot \tan x\right) \cdot \tan x \end{array} \]
(FPCore (x eps) :precision binary64 (+ eps (* (* eps (tan x)) (tan x))))
double code(double x, double eps) {
	return eps + ((eps * tan(x)) * tan(x));
}
module fmin_fmax_functions
    implicit none
    private
    public fmax
    public fmin

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

real(8) function code(x, eps)
use fmin_fmax_functions
    real(8), intent (in) :: x
    real(8), intent (in) :: eps
    code = eps + ((eps * tan(x)) * tan(x))
end function
public static double code(double x, double eps) {
	return eps + ((eps * Math.tan(x)) * Math.tan(x));
}
def code(x, eps):
	return eps + ((eps * math.tan(x)) * math.tan(x))
function code(x, eps)
	return Float64(eps + Float64(Float64(eps * tan(x)) * tan(x)))
end
function tmp = code(x, eps)
	tmp = eps + ((eps * tan(x)) * tan(x));
end
code[x_, eps_] := N[(eps + N[(N[(eps * N[Tan[x], $MachinePrecision]), $MachinePrecision] * N[Tan[x], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}

\\
\varepsilon + \left(\varepsilon \cdot \tan x\right) \cdot \tan x
\end{array}

Reproduce

?
herbie shell --seed 2025161 
(FPCore (x eps)
  :name "2tan (problem 3.3.2)"
  :precision binary64
  :pre (and (and (and (<= -10000.0 x) (<= x 10000.0)) (< (* 1e-16 (fabs x)) eps)) (< eps (fabs x)))

  :alt
  (! :herbie-platform c (/ (sin eps) (* (cos x) (cos (+ x eps)))))

  :alt
  (! :herbie-platform c (- (/ (+ (tan x) (tan eps)) (- 1 (* (tan x) (tan eps)))) (tan x)))

  :alt
  (! :herbie-platform c (+ eps (* eps (tan x) (tan x))))

  (- (tan (+ x eps)) (tan x)))