2tan (problem 3.3.2)

Percentage Accurate: 62.3% → 99.6%
Time: 11.5s
Alternatives: 12
Speedup: 207.0×

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}

Sampling outcomes in binary64 precision:

Local Percentage Accuracy vs ?

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

Accuracy vs Speed?

Herbie found 12 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: 62.3% 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, 0.1× speedup?

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

\\
\begin{array}{l}
t_0 := {\tan x}^{2}\\
\mathsf{fma}\left(\mathsf{fma}\left(\varepsilon \cdot \varepsilon, \mathsf{fma}\left(\mathsf{fma}\left(\mathsf{fma}\left(\sin x \cdot \tan x, \frac{-1}{\cos x}, -1\right), t\_0, \mathsf{fma}\left(0.16666666666666666, t\_0, \mathsf{fma}\left(t\_0, -0.5, -0.5\right)\right)\right), -1, -0.16666666666666666\right), \mathsf{fma}\left(t\_0, \varepsilon, \varepsilon\right) \cdot \tan x\right) + t\_0, \varepsilon, \varepsilon\right)
\end{array}
\end{array}
Derivation
  1. Initial program 64.6%

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

    \[\leadsto \color{blue}{\varepsilon \cdot \left(\left(1 + \varepsilon \cdot \left(-1 \cdot \left(\varepsilon \cdot \left(\frac{1}{6} + \left(-1 \cdot \frac{{\sin x}^{2} \cdot \left(1 - -1 \cdot \frac{{\sin x}^{2}}{{\cos x}^{2}}\right)}{{\cos x}^{2}} + \left(\frac{-1}{2} \cdot \left(1 - -1 \cdot \frac{{\sin x}^{2}}{{\cos x}^{2}}\right) + \frac{1}{6} \cdot \frac{{\sin x}^{2}}{{\cos x}^{2}}\right)\right)\right)\right) - -1 \cdot \frac{\sin x \cdot \left(1 - -1 \cdot \frac{{\sin x}^{2}}{{\cos x}^{2}}\right)}{\cos x}\right)\right) - -1 \cdot \frac{{\sin x}^{2}}{{\cos x}^{2}}\right)} \]
  4. Applied rewrites99.8%

    \[\leadsto \color{blue}{\mathsf{fma}\left(\mathsf{fma}\left(\mathsf{fma}\left(\mathsf{fma}\left(\mathsf{fma}\left(\sin x, \frac{\sin x}{{\cos x}^{2}}, 1\right), -0.5, \frac{\mathsf{fma}\left(\mathsf{fma}\left({\sin x}^{2}, \frac{-1}{{\cos x}^{2}}, -1\right), {\sin x}^{2}, {\sin x}^{2} \cdot 0.16666666666666666\right)}{{\cos x}^{2}}\right), -1, -0.16666666666666666\right) \cdot \varepsilon, \varepsilon, \frac{\mathsf{fma}\left(\mathsf{fma}\left(\frac{{\sin x}^{2}}{{\cos x}^{2}}, \varepsilon, \varepsilon\right), \sin x, \frac{{\sin x}^{2}}{\cos x}\right)}{\cos x}\right), \varepsilon, \varepsilon\right)} \]
  5. Applied rewrites99.8%

    \[\leadsto \mathsf{fma}\left(\mathsf{fma}\left(\varepsilon \cdot \varepsilon, \mathsf{fma}\left(\mathsf{fma}\left(\mathsf{fma}\left(\sin x \cdot \tan x, \frac{-1}{\cos x}, -1\right), {\tan x}^{2}, \mathsf{fma}\left(0.16666666666666666, {\tan x}^{2}, \mathsf{fma}\left({\tan x}^{2}, -0.5, -0.5\right)\right)\right), -1, -0.16666666666666666\right), \mathsf{fma}\left({\tan x}^{2}, \varepsilon, \varepsilon\right) \cdot \tan x\right) + {\tan x}^{2}, \varepsilon, \varepsilon\right) \]
  6. Add Preprocessing

Alternative 2: 99.6% accurate, 0.1× speedup?

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

\\
\begin{array}{l}
t_0 := {\tan x}^{2}\\
\mathsf{fma}\left(\mathsf{fma}\left(\mathsf{fma}\left(\mathsf{fma}\left(\mathsf{fma}\left(\sin x \cdot \tan x, \frac{-1}{\cos x}, -1\right), t\_0, \mathsf{fma}\left(0.16666666666666666, t\_0, \mathsf{fma}\left(t\_0, -0.5, -0.5\right)\right)\right), -1, -0.16666666666666666\right), \varepsilon \cdot \varepsilon, \mathsf{fma}\left(\mathsf{fma}\left(t\_0, \varepsilon, \varepsilon\right), \tan x, t\_0\right)\right), \varepsilon, \varepsilon\right)
\end{array}
\end{array}
Derivation
  1. Initial program 64.6%

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

    \[\leadsto \color{blue}{\varepsilon \cdot \left(\left(1 + \varepsilon \cdot \left(-1 \cdot \left(\varepsilon \cdot \left(\frac{1}{6} + \left(-1 \cdot \frac{{\sin x}^{2} \cdot \left(1 - -1 \cdot \frac{{\sin x}^{2}}{{\cos x}^{2}}\right)}{{\cos x}^{2}} + \left(\frac{-1}{2} \cdot \left(1 - -1 \cdot \frac{{\sin x}^{2}}{{\cos x}^{2}}\right) + \frac{1}{6} \cdot \frac{{\sin x}^{2}}{{\cos x}^{2}}\right)\right)\right)\right) - -1 \cdot \frac{\sin x \cdot \left(1 - -1 \cdot \frac{{\sin x}^{2}}{{\cos x}^{2}}\right)}{\cos x}\right)\right) - -1 \cdot \frac{{\sin x}^{2}}{{\cos x}^{2}}\right)} \]
  4. Applied rewrites99.8%

    \[\leadsto \color{blue}{\mathsf{fma}\left(\mathsf{fma}\left(\mathsf{fma}\left(\mathsf{fma}\left(\mathsf{fma}\left(\sin x, \frac{\sin x}{{\cos x}^{2}}, 1\right), -0.5, \frac{\mathsf{fma}\left(\mathsf{fma}\left({\sin x}^{2}, \frac{-1}{{\cos x}^{2}}, -1\right), {\sin x}^{2}, {\sin x}^{2} \cdot 0.16666666666666666\right)}{{\cos x}^{2}}\right), -1, -0.16666666666666666\right) \cdot \varepsilon, \varepsilon, \frac{\mathsf{fma}\left(\mathsf{fma}\left(\frac{{\sin x}^{2}}{{\cos x}^{2}}, \varepsilon, \varepsilon\right), \sin x, \frac{{\sin x}^{2}}{\cos x}\right)}{\cos x}\right), \varepsilon, \varepsilon\right)} \]
  5. Applied rewrites99.8%

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

Alternative 3: 99.5% accurate, 0.2× speedup?

\[\begin{array}{l} \\ \mathsf{fma}\left(\mathsf{fma}\left(\tan x, \mathsf{fma}\left(\mathsf{fma}\left(\tan x, \tan x, 1\right), \varepsilon, \tan x\right), \mathsf{fma}\left(\mathsf{fma}\left({\tan x}^{2}, \mathsf{fma}\left(\frac{-1}{\cos x} \cdot \sin x, \tan x, -1\right), -0.5\right), -1, -0.16666666666666666\right) \cdot \left(\varepsilon \cdot \varepsilon\right)\right), \varepsilon, \varepsilon\right) \end{array} \]
(FPCore (x eps)
 :precision binary64
 (fma
  (fma
   (tan x)
   (fma (fma (tan x) (tan x) 1.0) eps (tan x))
   (*
    (fma
     (fma
      (pow (tan x) 2.0)
      (fma (* (/ -1.0 (cos x)) (sin x)) (tan x) -1.0)
      -0.5)
     -1.0
     -0.16666666666666666)
    (* eps eps)))
  eps
  eps))
double code(double x, double eps) {
	return fma(fma(tan(x), fma(fma(tan(x), tan(x), 1.0), eps, tan(x)), (fma(fma(pow(tan(x), 2.0), fma(((-1.0 / cos(x)) * sin(x)), tan(x), -1.0), -0.5), -1.0, -0.16666666666666666) * (eps * eps))), eps, eps);
}
function code(x, eps)
	return fma(fma(tan(x), fma(fma(tan(x), tan(x), 1.0), eps, tan(x)), Float64(fma(fma((tan(x) ^ 2.0), fma(Float64(Float64(-1.0 / cos(x)) * sin(x)), tan(x), -1.0), -0.5), -1.0, -0.16666666666666666) * Float64(eps * eps))), eps, eps)
end
code[x_, eps_] := N[(N[(N[Tan[x], $MachinePrecision] * N[(N[(N[Tan[x], $MachinePrecision] * N[Tan[x], $MachinePrecision] + 1.0), $MachinePrecision] * eps + N[Tan[x], $MachinePrecision]), $MachinePrecision] + N[(N[(N[(N[Power[N[Tan[x], $MachinePrecision], 2.0], $MachinePrecision] * N[(N[(N[(-1.0 / N[Cos[x], $MachinePrecision]), $MachinePrecision] * N[Sin[x], $MachinePrecision]), $MachinePrecision] * N[Tan[x], $MachinePrecision] + -1.0), $MachinePrecision] + -0.5), $MachinePrecision] * -1.0 + -0.16666666666666666), $MachinePrecision] * N[(eps * eps), $MachinePrecision]), $MachinePrecision]), $MachinePrecision] * eps + eps), $MachinePrecision]
\begin{array}{l}

\\
\mathsf{fma}\left(\mathsf{fma}\left(\tan x, \mathsf{fma}\left(\mathsf{fma}\left(\tan x, \tan x, 1\right), \varepsilon, \tan x\right), \mathsf{fma}\left(\mathsf{fma}\left({\tan x}^{2}, \mathsf{fma}\left(\frac{-1}{\cos x} \cdot \sin x, \tan x, -1\right), -0.5\right), -1, -0.16666666666666666\right) \cdot \left(\varepsilon \cdot \varepsilon\right)\right), \varepsilon, \varepsilon\right)
\end{array}
Derivation
  1. Initial program 64.6%

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

    \[\leadsto \color{blue}{\varepsilon \cdot \left(\left(1 + \varepsilon \cdot \left(-1 \cdot \left(\varepsilon \cdot \left(\frac{1}{6} + \left(-1 \cdot \frac{{\sin x}^{2} \cdot \left(1 - -1 \cdot \frac{{\sin x}^{2}}{{\cos x}^{2}}\right)}{{\cos x}^{2}} + \left(\frac{-1}{2} \cdot \left(1 - -1 \cdot \frac{{\sin x}^{2}}{{\cos x}^{2}}\right) + \frac{1}{6} \cdot \frac{{\sin x}^{2}}{{\cos x}^{2}}\right)\right)\right)\right) - -1 \cdot \frac{\sin x \cdot \left(1 - -1 \cdot \frac{{\sin x}^{2}}{{\cos x}^{2}}\right)}{\cos x}\right)\right) - -1 \cdot \frac{{\sin x}^{2}}{{\cos x}^{2}}\right)} \]
  4. Applied rewrites99.8%

    \[\leadsto \color{blue}{\mathsf{fma}\left(\mathsf{fma}\left(\mathsf{fma}\left(\mathsf{fma}\left(\mathsf{fma}\left(\sin x, \frac{\sin x}{{\cos x}^{2}}, 1\right), -0.5, \frac{\mathsf{fma}\left(\mathsf{fma}\left({\sin x}^{2}, \frac{-1}{{\cos x}^{2}}, -1\right), {\sin x}^{2}, {\sin x}^{2} \cdot 0.16666666666666666\right)}{{\cos x}^{2}}\right), -1, -0.16666666666666666\right) \cdot \varepsilon, \varepsilon, \frac{\mathsf{fma}\left(\mathsf{fma}\left(\frac{{\sin x}^{2}}{{\cos x}^{2}}, \varepsilon, \varepsilon\right), \sin x, \frac{{\sin x}^{2}}{\cos x}\right)}{\cos x}\right), \varepsilon, \varepsilon\right)} \]
  5. Applied rewrites99.8%

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

    \[\leadsto \mathsf{fma}\left(\mathsf{fma}\left(\varepsilon \cdot \varepsilon, \mathsf{fma}\left(\mathsf{fma}\left(\mathsf{fma}\left(\sin x \cdot \tan x, \frac{-1}{\cos x}, -1\right), {\tan x}^{2}, \frac{-1}{2}\right), -1, \frac{-1}{6}\right), \mathsf{fma}\left({\tan x}^{2}, \varepsilon, \varepsilon\right) \cdot \tan x\right) + {\tan x}^{2}, \varepsilon, \varepsilon\right) \]
  7. Step-by-step derivation
    1. Applied rewrites99.8%

      \[\leadsto \mathsf{fma}\left(\mathsf{fma}\left(\varepsilon \cdot \varepsilon, \mathsf{fma}\left(\mathsf{fma}\left(\mathsf{fma}\left(\sin x \cdot \tan x, \frac{-1}{\cos x}, -1\right), {\tan x}^{2}, -0.5\right), -1, -0.16666666666666666\right), \mathsf{fma}\left({\tan x}^{2}, \varepsilon, \varepsilon\right) \cdot \tan x\right) + {\tan x}^{2}, \varepsilon, \varepsilon\right) \]
    2. Step-by-step derivation
      1. Applied rewrites99.8%

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

      Alternative 4: 99.5% accurate, 0.2× speedup?

      \[\begin{array}{l} \\ \begin{array}{l} t_0 := {\tan x}^{2}\\ \mathsf{fma}\left(\mathsf{fma}\left(\varepsilon \cdot \varepsilon, \mathsf{fma}\left(\mathsf{fma}\left(\mathsf{fma}\left(\sin x \cdot \tan x, -1, -1\right), t\_0, -0.5\right), -1, -0.16666666666666666\right), \mathsf{fma}\left(t\_0, \varepsilon, \varepsilon\right) \cdot \tan x\right) + t\_0, \varepsilon, \varepsilon\right) \end{array} \end{array} \]
      (FPCore (x eps)
       :precision binary64
       (let* ((t_0 (pow (tan x) 2.0)))
         (fma
          (+
           (fma
            (* eps eps)
            (fma
             (fma (fma (* (sin x) (tan x)) -1.0 -1.0) t_0 -0.5)
             -1.0
             -0.16666666666666666)
            (* (fma t_0 eps eps) (tan x)))
           t_0)
          eps
          eps)))
      double code(double x, double eps) {
      	double t_0 = pow(tan(x), 2.0);
      	return fma((fma((eps * eps), fma(fma(fma((sin(x) * tan(x)), -1.0, -1.0), t_0, -0.5), -1.0, -0.16666666666666666), (fma(t_0, eps, eps) * tan(x))) + t_0), eps, eps);
      }
      
      function code(x, eps)
      	t_0 = tan(x) ^ 2.0
      	return fma(Float64(fma(Float64(eps * eps), fma(fma(fma(Float64(sin(x) * tan(x)), -1.0, -1.0), t_0, -0.5), -1.0, -0.16666666666666666), Float64(fma(t_0, eps, eps) * tan(x))) + t_0), eps, eps)
      end
      
      code[x_, eps_] := Block[{t$95$0 = N[Power[N[Tan[x], $MachinePrecision], 2.0], $MachinePrecision]}, N[(N[(N[(N[(eps * eps), $MachinePrecision] * N[(N[(N[(N[(N[Sin[x], $MachinePrecision] * N[Tan[x], $MachinePrecision]), $MachinePrecision] * -1.0 + -1.0), $MachinePrecision] * t$95$0 + -0.5), $MachinePrecision] * -1.0 + -0.16666666666666666), $MachinePrecision] + N[(N[(t$95$0 * eps + eps), $MachinePrecision] * N[Tan[x], $MachinePrecision]), $MachinePrecision]), $MachinePrecision] + t$95$0), $MachinePrecision] * eps + eps), $MachinePrecision]]
      
      \begin{array}{l}
      
      \\
      \begin{array}{l}
      t_0 := {\tan x}^{2}\\
      \mathsf{fma}\left(\mathsf{fma}\left(\varepsilon \cdot \varepsilon, \mathsf{fma}\left(\mathsf{fma}\left(\mathsf{fma}\left(\sin x \cdot \tan x, -1, -1\right), t\_0, -0.5\right), -1, -0.16666666666666666\right), \mathsf{fma}\left(t\_0, \varepsilon, \varepsilon\right) \cdot \tan x\right) + t\_0, \varepsilon, \varepsilon\right)
      \end{array}
      \end{array}
      
      Derivation
      1. Initial program 64.6%

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

        \[\leadsto \color{blue}{\varepsilon \cdot \left(\left(1 + \varepsilon \cdot \left(-1 \cdot \left(\varepsilon \cdot \left(\frac{1}{6} + \left(-1 \cdot \frac{{\sin x}^{2} \cdot \left(1 - -1 \cdot \frac{{\sin x}^{2}}{{\cos x}^{2}}\right)}{{\cos x}^{2}} + \left(\frac{-1}{2} \cdot \left(1 - -1 \cdot \frac{{\sin x}^{2}}{{\cos x}^{2}}\right) + \frac{1}{6} \cdot \frac{{\sin x}^{2}}{{\cos x}^{2}}\right)\right)\right)\right) - -1 \cdot \frac{\sin x \cdot \left(1 - -1 \cdot \frac{{\sin x}^{2}}{{\cos x}^{2}}\right)}{\cos x}\right)\right) - -1 \cdot \frac{{\sin x}^{2}}{{\cos x}^{2}}\right)} \]
      4. Applied rewrites99.8%

        \[\leadsto \color{blue}{\mathsf{fma}\left(\mathsf{fma}\left(\mathsf{fma}\left(\mathsf{fma}\left(\mathsf{fma}\left(\sin x, \frac{\sin x}{{\cos x}^{2}}, 1\right), -0.5, \frac{\mathsf{fma}\left(\mathsf{fma}\left({\sin x}^{2}, \frac{-1}{{\cos x}^{2}}, -1\right), {\sin x}^{2}, {\sin x}^{2} \cdot 0.16666666666666666\right)}{{\cos x}^{2}}\right), -1, -0.16666666666666666\right) \cdot \varepsilon, \varepsilon, \frac{\mathsf{fma}\left(\mathsf{fma}\left(\frac{{\sin x}^{2}}{{\cos x}^{2}}, \varepsilon, \varepsilon\right), \sin x, \frac{{\sin x}^{2}}{\cos x}\right)}{\cos x}\right), \varepsilon, \varepsilon\right)} \]
      5. Applied rewrites99.8%

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

        \[\leadsto \mathsf{fma}\left(\mathsf{fma}\left(\varepsilon \cdot \varepsilon, \mathsf{fma}\left(\mathsf{fma}\left(\mathsf{fma}\left(\sin x \cdot \tan x, \frac{-1}{\cos x}, -1\right), {\tan x}^{2}, \frac{-1}{2}\right), -1, \frac{-1}{6}\right), \mathsf{fma}\left({\tan x}^{2}, \varepsilon, \varepsilon\right) \cdot \tan x\right) + {\tan x}^{2}, \varepsilon, \varepsilon\right) \]
      7. Step-by-step derivation
        1. Applied rewrites99.8%

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

          \[\leadsto \mathsf{fma}\left(\mathsf{fma}\left(\varepsilon \cdot \varepsilon, \mathsf{fma}\left(\mathsf{fma}\left(\mathsf{fma}\left(\sin x \cdot \tan x, -1, -1\right), {\tan x}^{2}, \frac{-1}{2}\right), -1, \frac{-1}{6}\right), \mathsf{fma}\left({\tan x}^{2}, \varepsilon, \varepsilon\right) \cdot \tan x\right) + {\tan x}^{2}, \varepsilon, \varepsilon\right) \]
        3. Step-by-step derivation
          1. Applied rewrites99.8%

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

          Alternative 5: 99.3% accurate, 0.5× speedup?

          \[\begin{array}{l} \\ \mathsf{fma}\left(\varepsilon \cdot \tan x, \mathsf{fma}\left(\mathsf{fma}\left(\tan x, \tan x, 1\right), \varepsilon, \tan x\right), \varepsilon\right) \end{array} \]
          (FPCore (x eps)
           :precision binary64
           (fma (* eps (tan x)) (fma (fma (tan x) (tan x) 1.0) eps (tan x)) eps))
          double code(double x, double eps) {
          	return fma((eps * tan(x)), fma(fma(tan(x), tan(x), 1.0), eps, tan(x)), eps);
          }
          
          function code(x, eps)
          	return fma(Float64(eps * tan(x)), fma(fma(tan(x), tan(x), 1.0), eps, tan(x)), eps)
          end
          
          code[x_, eps_] := N[(N[(eps * N[Tan[x], $MachinePrecision]), $MachinePrecision] * N[(N[(N[Tan[x], $MachinePrecision] * N[Tan[x], $MachinePrecision] + 1.0), $MachinePrecision] * eps + N[Tan[x], $MachinePrecision]), $MachinePrecision] + eps), $MachinePrecision]
          
          \begin{array}{l}
          
          \\
          \mathsf{fma}\left(\varepsilon \cdot \tan x, \mathsf{fma}\left(\mathsf{fma}\left(\tan x, \tan x, 1\right), \varepsilon, \tan x\right), \varepsilon\right)
          \end{array}
          
          Derivation
          1. Initial program 64.6%

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

            \[\leadsto \color{blue}{\varepsilon \cdot \left(\left(1 + \frac{\varepsilon \cdot \left(\sin x \cdot \left(1 - -1 \cdot \frac{{\sin x}^{2}}{{\cos x}^{2}}\right)\right)}{\cos x}\right) - -1 \cdot \frac{{\sin x}^{2}}{{\cos x}^{2}}\right)} \]
          4. Step-by-step derivation
            1. Applied rewrites99.7%

              \[\leadsto \color{blue}{\mathsf{fma}\left(\frac{\mathsf{fma}\left(\mathsf{fma}\left(\frac{{\sin x}^{2}}{{\cos x}^{2}}, \varepsilon, \varepsilon\right), \sin x, \frac{{\sin x}^{2}}{\cos x}\right)}{\cos x}, \varepsilon, \varepsilon\right)} \]
            2. Step-by-step derivation
              1. Applied rewrites99.7%

                \[\leadsto \mathsf{fma}\left(\mathsf{fma}\left(\tan x, \tan x, \mathsf{fma}\left({\tan x}^{2}, \varepsilon, \varepsilon\right) \cdot \tan x\right), \varepsilon, \varepsilon\right) \]
              2. Step-by-step derivation
                1. Applied rewrites99.7%

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

                Alternative 6: 99.0% accurate, 1.0× speedup?

                \[\begin{array}{l} \\ \mathsf{fma}\left(\varepsilon \cdot \tan x, \varepsilon + \tan x, \varepsilon\right) \end{array} \]
                (FPCore (x eps) :precision binary64 (fma (* eps (tan x)) (+ eps (tan x)) eps))
                double code(double x, double eps) {
                	return fma((eps * tan(x)), (eps + tan(x)), eps);
                }
                
                function code(x, eps)
                	return fma(Float64(eps * tan(x)), Float64(eps + tan(x)), eps)
                end
                
                code[x_, eps_] := N[(N[(eps * N[Tan[x], $MachinePrecision]), $MachinePrecision] * N[(eps + N[Tan[x], $MachinePrecision]), $MachinePrecision] + eps), $MachinePrecision]
                
                \begin{array}{l}
                
                \\
                \mathsf{fma}\left(\varepsilon \cdot \tan x, \varepsilon + \tan x, \varepsilon\right)
                \end{array}
                
                Derivation
                1. Initial program 64.6%

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

                  \[\leadsto \color{blue}{\varepsilon \cdot \left(\left(1 + \frac{\varepsilon \cdot \left(\sin x \cdot \left(1 - -1 \cdot \frac{{\sin x}^{2}}{{\cos x}^{2}}\right)\right)}{\cos x}\right) - -1 \cdot \frac{{\sin x}^{2}}{{\cos x}^{2}}\right)} \]
                4. Step-by-step derivation
                  1. Applied rewrites99.7%

                    \[\leadsto \color{blue}{\mathsf{fma}\left(\frac{\mathsf{fma}\left(\mathsf{fma}\left(\frac{{\sin x}^{2}}{{\cos x}^{2}}, \varepsilon, \varepsilon\right), \sin x, \frac{{\sin x}^{2}}{\cos x}\right)}{\cos x}, \varepsilon, \varepsilon\right)} \]
                  2. Step-by-step derivation
                    1. Applied rewrites99.7%

                      \[\leadsto \mathsf{fma}\left(\mathsf{fma}\left(\tan x, \tan x, \mathsf{fma}\left({\tan x}^{2}, \varepsilon, \varepsilon\right) \cdot \tan x\right), \varepsilon, \varepsilon\right) \]
                    2. Taylor expanded in x around 0

                      \[\leadsto \mathsf{fma}\left(\mathsf{fma}\left(\tan x, \tan x, \varepsilon \cdot \tan x\right), \varepsilon, \varepsilon\right) \]
                    3. Step-by-step derivation
                      1. Applied rewrites99.5%

                        \[\leadsto \mathsf{fma}\left(\mathsf{fma}\left(\tan x, \tan x, \varepsilon \cdot \tan x\right), \varepsilon, \varepsilon\right) \]
                      2. Step-by-step derivation
                        1. Applied rewrites99.5%

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

                        Alternative 7: 98.9% accurate, 1.0× speedup?

                        \[\begin{array}{l} \\ \mathsf{fma}\left({\tan x}^{2}, \varepsilon, \varepsilon\right) \end{array} \]
                        (FPCore (x eps) :precision binary64 (fma (pow (tan x) 2.0) eps eps))
                        double code(double x, double eps) {
                        	return fma(pow(tan(x), 2.0), eps, eps);
                        }
                        
                        function code(x, eps)
                        	return fma((tan(x) ^ 2.0), eps, eps)
                        end
                        
                        code[x_, eps_] := N[(N[Power[N[Tan[x], $MachinePrecision], 2.0], $MachinePrecision] * eps + eps), $MachinePrecision]
                        
                        \begin{array}{l}
                        
                        \\
                        \mathsf{fma}\left({\tan x}^{2}, \varepsilon, \varepsilon\right)
                        \end{array}
                        
                        Derivation
                        1. Initial program 64.6%

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

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

                            \[\leadsto \color{blue}{\mathsf{fma}\left(\frac{{\sin x}^{2}}{{\cos x}^{2}}, \varepsilon, \varepsilon\right)} \]
                          2. Step-by-step derivation
                            1. Applied rewrites99.4%

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

                            Alternative 8: 98.1% accurate, 8.0× speedup?

                            \[\begin{array}{l} \\ \mathsf{fma}\left(\mathsf{fma}\left(\varepsilon + x, x, \left(\varepsilon \cdot \varepsilon\right) \cdot 0.3333333333333333\right), \varepsilon, \varepsilon\right) \end{array} \]
                            (FPCore (x eps)
                             :precision binary64
                             (fma (fma (+ eps x) x (* (* eps eps) 0.3333333333333333)) eps eps))
                            double code(double x, double eps) {
                            	return fma(fma((eps + x), x, ((eps * eps) * 0.3333333333333333)), eps, eps);
                            }
                            
                            function code(x, eps)
                            	return fma(fma(Float64(eps + x), x, Float64(Float64(eps * eps) * 0.3333333333333333)), eps, eps)
                            end
                            
                            code[x_, eps_] := N[(N[(N[(eps + x), $MachinePrecision] * x + N[(N[(eps * eps), $MachinePrecision] * 0.3333333333333333), $MachinePrecision]), $MachinePrecision] * eps + eps), $MachinePrecision]
                            
                            \begin{array}{l}
                            
                            \\
                            \mathsf{fma}\left(\mathsf{fma}\left(\varepsilon + x, x, \left(\varepsilon \cdot \varepsilon\right) \cdot 0.3333333333333333\right), \varepsilon, \varepsilon\right)
                            \end{array}
                            
                            Derivation
                            1. Initial program 64.6%

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

                              \[\leadsto \color{blue}{\varepsilon \cdot \left(\left(1 + \varepsilon \cdot \left(-1 \cdot \left(\varepsilon \cdot \left(\frac{1}{6} + \left(-1 \cdot \frac{{\sin x}^{2} \cdot \left(1 - -1 \cdot \frac{{\sin x}^{2}}{{\cos x}^{2}}\right)}{{\cos x}^{2}} + \left(\frac{-1}{2} \cdot \left(1 - -1 \cdot \frac{{\sin x}^{2}}{{\cos x}^{2}}\right) + \frac{1}{6} \cdot \frac{{\sin x}^{2}}{{\cos x}^{2}}\right)\right)\right)\right) - -1 \cdot \frac{\sin x \cdot \left(1 - -1 \cdot \frac{{\sin x}^{2}}{{\cos x}^{2}}\right)}{\cos x}\right)\right) - -1 \cdot \frac{{\sin x}^{2}}{{\cos x}^{2}}\right)} \]
                            4. Applied rewrites99.8%

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

                              \[\leadsto \mathsf{fma}\left(\frac{1}{3} \cdot {\varepsilon}^{2} + x \cdot \left(\varepsilon + x \cdot \left(1 + \frac{4}{3} \cdot {\varepsilon}^{2}\right)\right), \varepsilon, \varepsilon\right) \]
                            6. Step-by-step derivation
                              1. Applied rewrites99.0%

                                \[\leadsto \mathsf{fma}\left(\mathsf{fma}\left(\mathsf{fma}\left(\mathsf{fma}\left(1.3333333333333333, \varepsilon \cdot \varepsilon, 1\right), x, \varepsilon\right), x, \left(\varepsilon \cdot \varepsilon\right) \cdot 0.3333333333333333\right), \varepsilon, \varepsilon\right) \]
                              2. Taylor expanded in eps around 0

                                \[\leadsto \mathsf{fma}\left(\mathsf{fma}\left(\varepsilon + x, x, \left(\varepsilon \cdot \varepsilon\right) \cdot \frac{1}{3}\right), \varepsilon, \varepsilon\right) \]
                              3. Step-by-step derivation
                                1. Applied rewrites99.0%

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

                                Alternative 9: 98.1% accurate, 13.8× speedup?

                                \[\begin{array}{l} \\ \mathsf{fma}\left(\left(\varepsilon + x\right) \cdot x, \varepsilon, \varepsilon\right) \end{array} \]
                                (FPCore (x eps) :precision binary64 (fma (* (+ eps x) x) eps eps))
                                double code(double x, double eps) {
                                	return fma(((eps + x) * x), eps, eps);
                                }
                                
                                function code(x, eps)
                                	return fma(Float64(Float64(eps + x) * x), eps, eps)
                                end
                                
                                code[x_, eps_] := N[(N[(N[(eps + x), $MachinePrecision] * x), $MachinePrecision] * eps + eps), $MachinePrecision]
                                
                                \begin{array}{l}
                                
                                \\
                                \mathsf{fma}\left(\left(\varepsilon + x\right) \cdot x, \varepsilon, \varepsilon\right)
                                \end{array}
                                
                                Derivation
                                1. Initial program 64.6%

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

                                  \[\leadsto \color{blue}{\varepsilon \cdot \left(\left(1 + \frac{\varepsilon \cdot \left(\sin x \cdot \left(1 - -1 \cdot \frac{{\sin x}^{2}}{{\cos x}^{2}}\right)\right)}{\cos x}\right) - -1 \cdot \frac{{\sin x}^{2}}{{\cos x}^{2}}\right)} \]
                                4. Step-by-step derivation
                                  1. Applied rewrites99.7%

                                    \[\leadsto \color{blue}{\mathsf{fma}\left(\frac{\mathsf{fma}\left(\mathsf{fma}\left(\frac{{\sin x}^{2}}{{\cos x}^{2}}, \varepsilon, \varepsilon\right), \sin x, \frac{{\sin x}^{2}}{\cos x}\right)}{\cos x}, \varepsilon, \varepsilon\right)} \]
                                  2. Taylor expanded in x around 0

                                    \[\leadsto \mathsf{fma}\left(x \cdot \left(\varepsilon + x\right), \varepsilon, \varepsilon\right) \]
                                  3. Step-by-step derivation
                                    1. Applied rewrites99.0%

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

                                    Alternative 10: 98.0% accurate, 17.3× speedup?

                                    \[\begin{array}{l} \\ \mathsf{fma}\left(x \cdot x, \varepsilon, \varepsilon\right) \end{array} \]
                                    (FPCore (x eps) :precision binary64 (fma (* x x) eps eps))
                                    double code(double x, double eps) {
                                    	return fma((x * x), eps, eps);
                                    }
                                    
                                    function code(x, eps)
                                    	return fma(Float64(x * x), eps, eps)
                                    end
                                    
                                    code[x_, eps_] := N[(N[(x * x), $MachinePrecision] * eps + eps), $MachinePrecision]
                                    
                                    \begin{array}{l}
                                    
                                    \\
                                    \mathsf{fma}\left(x \cdot x, \varepsilon, \varepsilon\right)
                                    \end{array}
                                    
                                    Derivation
                                    1. Initial program 64.6%

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

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

                                        \[\leadsto \color{blue}{\mathsf{fma}\left(\frac{{\sin x}^{2}}{{\cos x}^{2}}, \varepsilon, \varepsilon\right)} \]
                                      2. Taylor expanded in x around 0

                                        \[\leadsto \mathsf{fma}\left({x}^{2}, \varepsilon, \varepsilon\right) \]
                                      3. Step-by-step derivation
                                        1. Applied rewrites98.9%

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

                                        Alternative 11: 97.6% accurate, 17.3× speedup?

                                        \[\begin{array}{l} \\ \mathsf{fma}\left(\varepsilon \cdot x, \varepsilon, \varepsilon\right) \end{array} \]
                                        (FPCore (x eps) :precision binary64 (fma (* eps x) eps eps))
                                        double code(double x, double eps) {
                                        	return fma((eps * x), eps, eps);
                                        }
                                        
                                        function code(x, eps)
                                        	return fma(Float64(eps * x), eps, eps)
                                        end
                                        
                                        code[x_, eps_] := N[(N[(eps * x), $MachinePrecision] * eps + eps), $MachinePrecision]
                                        
                                        \begin{array}{l}
                                        
                                        \\
                                        \mathsf{fma}\left(\varepsilon \cdot x, \varepsilon, \varepsilon\right)
                                        \end{array}
                                        
                                        Derivation
                                        1. Initial program 64.6%

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

                                          \[\leadsto \color{blue}{\varepsilon \cdot \left(\left(1 + \frac{\varepsilon \cdot \left(\sin x \cdot \left(1 - -1 \cdot \frac{{\sin x}^{2}}{{\cos x}^{2}}\right)\right)}{\cos x}\right) - -1 \cdot \frac{{\sin x}^{2}}{{\cos x}^{2}}\right)} \]
                                        4. Step-by-step derivation
                                          1. Applied rewrites99.7%

                                            \[\leadsto \color{blue}{\mathsf{fma}\left(\frac{\mathsf{fma}\left(\mathsf{fma}\left(\frac{{\sin x}^{2}}{{\cos x}^{2}}, \varepsilon, \varepsilon\right), \sin x, \frac{{\sin x}^{2}}{\cos x}\right)}{\cos x}, \varepsilon, \varepsilon\right)} \]
                                          2. Taylor expanded in x around 0

                                            \[\leadsto \mathsf{fma}\left(\varepsilon \cdot x, \varepsilon, \varepsilon\right) \]
                                          3. Step-by-step derivation
                                            1. Applied rewrites98.7%

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

                                            Alternative 12: 97.6% accurate, 207.0× 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 64.6%

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

                                              \[\leadsto \color{blue}{\frac{\sin \varepsilon}{\cos \varepsilon}} \]
                                            4. Step-by-step derivation
                                              1. Applied rewrites98.7%

                                                \[\leadsto \color{blue}{\frac{\sin \varepsilon}{\cos \varepsilon}} \]
                                              2. Taylor expanded in eps around 0

                                                \[\leadsto \varepsilon \]
                                              3. Step-by-step derivation
                                                1. Applied rewrites98.7%

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

                                                Developer Target 1: 98.9% 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 2025018 
                                                (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 default (+ eps (* eps (tan x) (tan x))))
                                                
                                                  (- (tan (+ x eps)) (tan x)))