sintan (problem 3.4.5)

Percentage Accurate: 1.6% → 99.9%
Time: 19.6s
Alternatives: 5
Speedup: 218.0×

Specification

?
\[-0.4 \leq \varepsilon \land \varepsilon \leq 0.4\]
\[\begin{array}{l} \\ \frac{\varepsilon - \sin \varepsilon}{\varepsilon - \tan \varepsilon} \end{array} \]
(FPCore (eps) :precision binary64 (/ (- eps (sin eps)) (- eps (tan eps))))
double code(double eps) {
	return (eps - sin(eps)) / (eps - tan(eps));
}
real(8) function code(eps)
    real(8), intent (in) :: eps
    code = (eps - sin(eps)) / (eps - tan(eps))
end function
public static double code(double eps) {
	return (eps - Math.sin(eps)) / (eps - Math.tan(eps));
}
def code(eps):
	return (eps - math.sin(eps)) / (eps - math.tan(eps))
function code(eps)
	return Float64(Float64(eps - sin(eps)) / Float64(eps - tan(eps)))
end
function tmp = code(eps)
	tmp = (eps - sin(eps)) / (eps - tan(eps));
end
code[eps_] := N[(N[(eps - N[Sin[eps], $MachinePrecision]), $MachinePrecision] / N[(eps - N[Tan[eps], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}

\\
\frac{\varepsilon - \sin \varepsilon}{\varepsilon - \tan \varepsilon}
\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 5 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: 1.6% accurate, 1.0× speedup?

\[\begin{array}{l} \\ \frac{\varepsilon - \sin \varepsilon}{\varepsilon - \tan \varepsilon} \end{array} \]
(FPCore (eps) :precision binary64 (/ (- eps (sin eps)) (- eps (tan eps))))
double code(double eps) {
	return (eps - sin(eps)) / (eps - tan(eps));
}
real(8) function code(eps)
    real(8), intent (in) :: eps
    code = (eps - sin(eps)) / (eps - tan(eps))
end function
public static double code(double eps) {
	return (eps - Math.sin(eps)) / (eps - Math.tan(eps));
}
def code(eps):
	return (eps - math.sin(eps)) / (eps - math.tan(eps))
function code(eps)
	return Float64(Float64(eps - sin(eps)) / Float64(eps - tan(eps)))
end
function tmp = code(eps)
	tmp = (eps - sin(eps)) / (eps - tan(eps));
end
code[eps_] := N[(N[(eps - N[Sin[eps], $MachinePrecision]), $MachinePrecision] / N[(eps - N[Tan[eps], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}

\\
\frac{\varepsilon - \sin \varepsilon}{\varepsilon - \tan \varepsilon}
\end{array}

Alternative 1: 99.9% accurate, 6.4× speedup?

\[\begin{array}{l} \\ \mathsf{fma}\left(\varepsilon \cdot \varepsilon, \mathsf{fma}\left(\varepsilon, \varepsilon \cdot \mathsf{fma}\left(\varepsilon, \varepsilon \cdot 0.00024107142857142857, -0.009642857142857142\right), 0.225\right), -0.5\right) \end{array} \]
(FPCore (eps)
 :precision binary64
 (fma
  (* eps eps)
  (fma
   eps
   (* eps (fma eps (* eps 0.00024107142857142857) -0.009642857142857142))
   0.225)
  -0.5))
double code(double eps) {
	return fma((eps * eps), fma(eps, (eps * fma(eps, (eps * 0.00024107142857142857), -0.009642857142857142)), 0.225), -0.5);
}
function code(eps)
	return fma(Float64(eps * eps), fma(eps, Float64(eps * fma(eps, Float64(eps * 0.00024107142857142857), -0.009642857142857142)), 0.225), -0.5)
end
code[eps_] := N[(N[(eps * eps), $MachinePrecision] * N[(eps * N[(eps * N[(eps * N[(eps * 0.00024107142857142857), $MachinePrecision] + -0.009642857142857142), $MachinePrecision]), $MachinePrecision] + 0.225), $MachinePrecision] + -0.5), $MachinePrecision]
\begin{array}{l}

\\
\mathsf{fma}\left(\varepsilon \cdot \varepsilon, \mathsf{fma}\left(\varepsilon, \varepsilon \cdot \mathsf{fma}\left(\varepsilon, \varepsilon \cdot 0.00024107142857142857, -0.009642857142857142\right), 0.225\right), -0.5\right)
\end{array}
Derivation
  1. Initial program 1.7%

    \[\frac{\varepsilon - \sin \varepsilon}{\varepsilon - \tan \varepsilon} \]
  2. Add Preprocessing
  3. Taylor expanded in eps around 0

    \[\leadsto \color{blue}{{\varepsilon}^{2} \cdot \left(\frac{9}{40} + {\varepsilon}^{2} \cdot \left(\frac{27}{112000} \cdot {\varepsilon}^{2} - \frac{27}{2800}\right)\right) - \frac{1}{2}} \]
  4. Step-by-step derivation
    1. sub-negN/A

      \[\leadsto \color{blue}{{\varepsilon}^{2} \cdot \left(\frac{9}{40} + {\varepsilon}^{2} \cdot \left(\frac{27}{112000} \cdot {\varepsilon}^{2} - \frac{27}{2800}\right)\right) + \left(\mathsf{neg}\left(\frac{1}{2}\right)\right)} \]
    2. lower-fma.f64N/A

      \[\leadsto \color{blue}{\mathsf{fma}\left({\varepsilon}^{2}, \frac{9}{40} + {\varepsilon}^{2} \cdot \left(\frac{27}{112000} \cdot {\varepsilon}^{2} - \frac{27}{2800}\right), \mathsf{neg}\left(\frac{1}{2}\right)\right)} \]
    3. unpow2N/A

      \[\leadsto \mathsf{fma}\left(\color{blue}{\varepsilon \cdot \varepsilon}, \frac{9}{40} + {\varepsilon}^{2} \cdot \left(\frac{27}{112000} \cdot {\varepsilon}^{2} - \frac{27}{2800}\right), \mathsf{neg}\left(\frac{1}{2}\right)\right) \]
    4. lower-*.f64N/A

      \[\leadsto \mathsf{fma}\left(\color{blue}{\varepsilon \cdot \varepsilon}, \frac{9}{40} + {\varepsilon}^{2} \cdot \left(\frac{27}{112000} \cdot {\varepsilon}^{2} - \frac{27}{2800}\right), \mathsf{neg}\left(\frac{1}{2}\right)\right) \]
    5. +-commutativeN/A

      \[\leadsto \mathsf{fma}\left(\varepsilon \cdot \varepsilon, \color{blue}{{\varepsilon}^{2} \cdot \left(\frac{27}{112000} \cdot {\varepsilon}^{2} - \frac{27}{2800}\right) + \frac{9}{40}}, \mathsf{neg}\left(\frac{1}{2}\right)\right) \]
    6. unpow2N/A

      \[\leadsto \mathsf{fma}\left(\varepsilon \cdot \varepsilon, \color{blue}{\left(\varepsilon \cdot \varepsilon\right)} \cdot \left(\frac{27}{112000} \cdot {\varepsilon}^{2} - \frac{27}{2800}\right) + \frac{9}{40}, \mathsf{neg}\left(\frac{1}{2}\right)\right) \]
    7. associate-*l*N/A

      \[\leadsto \mathsf{fma}\left(\varepsilon \cdot \varepsilon, \color{blue}{\varepsilon \cdot \left(\varepsilon \cdot \left(\frac{27}{112000} \cdot {\varepsilon}^{2} - \frac{27}{2800}\right)\right)} + \frac{9}{40}, \mathsf{neg}\left(\frac{1}{2}\right)\right) \]
    8. lower-fma.f64N/A

      \[\leadsto \mathsf{fma}\left(\varepsilon \cdot \varepsilon, \color{blue}{\mathsf{fma}\left(\varepsilon, \varepsilon \cdot \left(\frac{27}{112000} \cdot {\varepsilon}^{2} - \frac{27}{2800}\right), \frac{9}{40}\right)}, \mathsf{neg}\left(\frac{1}{2}\right)\right) \]
    9. lower-*.f64N/A

      \[\leadsto \mathsf{fma}\left(\varepsilon \cdot \varepsilon, \mathsf{fma}\left(\varepsilon, \color{blue}{\varepsilon \cdot \left(\frac{27}{112000} \cdot {\varepsilon}^{2} - \frac{27}{2800}\right)}, \frac{9}{40}\right), \mathsf{neg}\left(\frac{1}{2}\right)\right) \]
    10. sub-negN/A

      \[\leadsto \mathsf{fma}\left(\varepsilon \cdot \varepsilon, \mathsf{fma}\left(\varepsilon, \varepsilon \cdot \color{blue}{\left(\frac{27}{112000} \cdot {\varepsilon}^{2} + \left(\mathsf{neg}\left(\frac{27}{2800}\right)\right)\right)}, \frac{9}{40}\right), \mathsf{neg}\left(\frac{1}{2}\right)\right) \]
    11. unpow2N/A

      \[\leadsto \mathsf{fma}\left(\varepsilon \cdot \varepsilon, \mathsf{fma}\left(\varepsilon, \varepsilon \cdot \left(\frac{27}{112000} \cdot \color{blue}{\left(\varepsilon \cdot \varepsilon\right)} + \left(\mathsf{neg}\left(\frac{27}{2800}\right)\right)\right), \frac{9}{40}\right), \mathsf{neg}\left(\frac{1}{2}\right)\right) \]
    12. associate-*r*N/A

      \[\leadsto \mathsf{fma}\left(\varepsilon \cdot \varepsilon, \mathsf{fma}\left(\varepsilon, \varepsilon \cdot \left(\color{blue}{\left(\frac{27}{112000} \cdot \varepsilon\right) \cdot \varepsilon} + \left(\mathsf{neg}\left(\frac{27}{2800}\right)\right)\right), \frac{9}{40}\right), \mathsf{neg}\left(\frac{1}{2}\right)\right) \]
    13. *-commutativeN/A

      \[\leadsto \mathsf{fma}\left(\varepsilon \cdot \varepsilon, \mathsf{fma}\left(\varepsilon, \varepsilon \cdot \left(\color{blue}{\varepsilon \cdot \left(\frac{27}{112000} \cdot \varepsilon\right)} + \left(\mathsf{neg}\left(\frac{27}{2800}\right)\right)\right), \frac{9}{40}\right), \mathsf{neg}\left(\frac{1}{2}\right)\right) \]
    14. metadata-evalN/A

      \[\leadsto \mathsf{fma}\left(\varepsilon \cdot \varepsilon, \mathsf{fma}\left(\varepsilon, \varepsilon \cdot \left(\varepsilon \cdot \left(\frac{27}{112000} \cdot \varepsilon\right) + \color{blue}{\frac{-27}{2800}}\right), \frac{9}{40}\right), \mathsf{neg}\left(\frac{1}{2}\right)\right) \]
    15. lower-fma.f64N/A

      \[\leadsto \mathsf{fma}\left(\varepsilon \cdot \varepsilon, \mathsf{fma}\left(\varepsilon, \varepsilon \cdot \color{blue}{\mathsf{fma}\left(\varepsilon, \frac{27}{112000} \cdot \varepsilon, \frac{-27}{2800}\right)}, \frac{9}{40}\right), \mathsf{neg}\left(\frac{1}{2}\right)\right) \]
    16. *-commutativeN/A

      \[\leadsto \mathsf{fma}\left(\varepsilon \cdot \varepsilon, \mathsf{fma}\left(\varepsilon, \varepsilon \cdot \mathsf{fma}\left(\varepsilon, \color{blue}{\varepsilon \cdot \frac{27}{112000}}, \frac{-27}{2800}\right), \frac{9}{40}\right), \mathsf{neg}\left(\frac{1}{2}\right)\right) \]
    17. lower-*.f64N/A

      \[\leadsto \mathsf{fma}\left(\varepsilon \cdot \varepsilon, \mathsf{fma}\left(\varepsilon, \varepsilon \cdot \mathsf{fma}\left(\varepsilon, \color{blue}{\varepsilon \cdot \frac{27}{112000}}, \frac{-27}{2800}\right), \frac{9}{40}\right), \mathsf{neg}\left(\frac{1}{2}\right)\right) \]
    18. metadata-eval99.9

      \[\leadsto \mathsf{fma}\left(\varepsilon \cdot \varepsilon, \mathsf{fma}\left(\varepsilon, \varepsilon \cdot \mathsf{fma}\left(\varepsilon, \varepsilon \cdot 0.00024107142857142857, -0.009642857142857142\right), 0.225\right), \color{blue}{-0.5}\right) \]
  5. Applied rewrites99.9%

    \[\leadsto \color{blue}{\mathsf{fma}\left(\varepsilon \cdot \varepsilon, \mathsf{fma}\left(\varepsilon, \varepsilon \cdot \mathsf{fma}\left(\varepsilon, \varepsilon \cdot 0.00024107142857142857, -0.009642857142857142\right), 0.225\right), -0.5\right)} \]
  6. Add Preprocessing

Alternative 2: 99.8% accurate, 6.6× speedup?

\[\begin{array}{l} \\ \mathsf{fma}\left(\varepsilon \cdot \left(\varepsilon \cdot \left(\varepsilon \cdot -0.009642857142857142\right)\right), \varepsilon, \mathsf{fma}\left(\varepsilon, \varepsilon \cdot 0.225, -0.5\right)\right) \end{array} \]
(FPCore (eps)
 :precision binary64
 (fma
  (* eps (* eps (* eps -0.009642857142857142)))
  eps
  (fma eps (* eps 0.225) -0.5)))
double code(double eps) {
	return fma((eps * (eps * (eps * -0.009642857142857142))), eps, fma(eps, (eps * 0.225), -0.5));
}
function code(eps)
	return fma(Float64(eps * Float64(eps * Float64(eps * -0.009642857142857142))), eps, fma(eps, Float64(eps * 0.225), -0.5))
end
code[eps_] := N[(N[(eps * N[(eps * N[(eps * -0.009642857142857142), $MachinePrecision]), $MachinePrecision]), $MachinePrecision] * eps + N[(eps * N[(eps * 0.225), $MachinePrecision] + -0.5), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}

\\
\mathsf{fma}\left(\varepsilon \cdot \left(\varepsilon \cdot \left(\varepsilon \cdot -0.009642857142857142\right)\right), \varepsilon, \mathsf{fma}\left(\varepsilon, \varepsilon \cdot 0.225, -0.5\right)\right)
\end{array}
Derivation
  1. Initial program 1.7%

    \[\frac{\varepsilon - \sin \varepsilon}{\varepsilon - \tan \varepsilon} \]
  2. Add Preprocessing
  3. Taylor expanded in eps around 0

    \[\leadsto \color{blue}{{\varepsilon}^{2} \cdot \left(\frac{9}{40} + \frac{-27}{2800} \cdot {\varepsilon}^{2}\right) - \frac{1}{2}} \]
  4. Step-by-step derivation
    1. sub-negN/A

      \[\leadsto \color{blue}{{\varepsilon}^{2} \cdot \left(\frac{9}{40} + \frac{-27}{2800} \cdot {\varepsilon}^{2}\right) + \left(\mathsf{neg}\left(\frac{1}{2}\right)\right)} \]
    2. lower-fma.f64N/A

      \[\leadsto \color{blue}{\mathsf{fma}\left({\varepsilon}^{2}, \frac{9}{40} + \frac{-27}{2800} \cdot {\varepsilon}^{2}, \mathsf{neg}\left(\frac{1}{2}\right)\right)} \]
    3. unpow2N/A

      \[\leadsto \mathsf{fma}\left(\color{blue}{\varepsilon \cdot \varepsilon}, \frac{9}{40} + \frac{-27}{2800} \cdot {\varepsilon}^{2}, \mathsf{neg}\left(\frac{1}{2}\right)\right) \]
    4. lower-*.f64N/A

      \[\leadsto \mathsf{fma}\left(\color{blue}{\varepsilon \cdot \varepsilon}, \frac{9}{40} + \frac{-27}{2800} \cdot {\varepsilon}^{2}, \mathsf{neg}\left(\frac{1}{2}\right)\right) \]
    5. +-commutativeN/A

      \[\leadsto \mathsf{fma}\left(\varepsilon \cdot \varepsilon, \color{blue}{\frac{-27}{2800} \cdot {\varepsilon}^{2} + \frac{9}{40}}, \mathsf{neg}\left(\frac{1}{2}\right)\right) \]
    6. *-commutativeN/A

      \[\leadsto \mathsf{fma}\left(\varepsilon \cdot \varepsilon, \color{blue}{{\varepsilon}^{2} \cdot \frac{-27}{2800}} + \frac{9}{40}, \mathsf{neg}\left(\frac{1}{2}\right)\right) \]
    7. unpow2N/A

      \[\leadsto \mathsf{fma}\left(\varepsilon \cdot \varepsilon, \color{blue}{\left(\varepsilon \cdot \varepsilon\right)} \cdot \frac{-27}{2800} + \frac{9}{40}, \mathsf{neg}\left(\frac{1}{2}\right)\right) \]
    8. associate-*l*N/A

      \[\leadsto \mathsf{fma}\left(\varepsilon \cdot \varepsilon, \color{blue}{\varepsilon \cdot \left(\varepsilon \cdot \frac{-27}{2800}\right)} + \frac{9}{40}, \mathsf{neg}\left(\frac{1}{2}\right)\right) \]
    9. lower-fma.f64N/A

      \[\leadsto \mathsf{fma}\left(\varepsilon \cdot \varepsilon, \color{blue}{\mathsf{fma}\left(\varepsilon, \varepsilon \cdot \frac{-27}{2800}, \frac{9}{40}\right)}, \mathsf{neg}\left(\frac{1}{2}\right)\right) \]
    10. lower-*.f64N/A

      \[\leadsto \mathsf{fma}\left(\varepsilon \cdot \varepsilon, \mathsf{fma}\left(\varepsilon, \color{blue}{\varepsilon \cdot \frac{-27}{2800}}, \frac{9}{40}\right), \mathsf{neg}\left(\frac{1}{2}\right)\right) \]
    11. metadata-eval99.9

      \[\leadsto \mathsf{fma}\left(\varepsilon \cdot \varepsilon, \mathsf{fma}\left(\varepsilon, \varepsilon \cdot -0.009642857142857142, 0.225\right), \color{blue}{-0.5}\right) \]
  5. Applied rewrites99.9%

    \[\leadsto \color{blue}{\mathsf{fma}\left(\varepsilon \cdot \varepsilon, \mathsf{fma}\left(\varepsilon, \varepsilon \cdot -0.009642857142857142, 0.225\right), -0.5\right)} \]
  6. Step-by-step derivation
    1. Applied rewrites99.9%

      \[\leadsto \mathsf{fma}\left(\left(\varepsilon \cdot \left(\varepsilon \cdot -0.009642857142857142\right)\right) \cdot \varepsilon, \color{blue}{\varepsilon}, \mathsf{fma}\left(\varepsilon, \varepsilon \cdot 0.225, -0.5\right)\right) \]
    2. Final simplification99.9%

      \[\leadsto \mathsf{fma}\left(\varepsilon \cdot \left(\varepsilon \cdot \left(\varepsilon \cdot -0.009642857142857142\right)\right), \varepsilon, \mathsf{fma}\left(\varepsilon, \varepsilon \cdot 0.225, -0.5\right)\right) \]
    3. Add Preprocessing

    Alternative 3: 99.8% accurate, 9.5× speedup?

    \[\begin{array}{l} \\ \mathsf{fma}\left(\varepsilon \cdot \varepsilon, \mathsf{fma}\left(\varepsilon, \varepsilon \cdot -0.009642857142857142, 0.225\right), -0.5\right) \end{array} \]
    (FPCore (eps)
     :precision binary64
     (fma (* eps eps) (fma eps (* eps -0.009642857142857142) 0.225) -0.5))
    double code(double eps) {
    	return fma((eps * eps), fma(eps, (eps * -0.009642857142857142), 0.225), -0.5);
    }
    
    function code(eps)
    	return fma(Float64(eps * eps), fma(eps, Float64(eps * -0.009642857142857142), 0.225), -0.5)
    end
    
    code[eps_] := N[(N[(eps * eps), $MachinePrecision] * N[(eps * N[(eps * -0.009642857142857142), $MachinePrecision] + 0.225), $MachinePrecision] + -0.5), $MachinePrecision]
    
    \begin{array}{l}
    
    \\
    \mathsf{fma}\left(\varepsilon \cdot \varepsilon, \mathsf{fma}\left(\varepsilon, \varepsilon \cdot -0.009642857142857142, 0.225\right), -0.5\right)
    \end{array}
    
    Derivation
    1. Initial program 1.7%

      \[\frac{\varepsilon - \sin \varepsilon}{\varepsilon - \tan \varepsilon} \]
    2. Add Preprocessing
    3. Taylor expanded in eps around 0

      \[\leadsto \color{blue}{{\varepsilon}^{2} \cdot \left(\frac{9}{40} + \frac{-27}{2800} \cdot {\varepsilon}^{2}\right) - \frac{1}{2}} \]
    4. Step-by-step derivation
      1. sub-negN/A

        \[\leadsto \color{blue}{{\varepsilon}^{2} \cdot \left(\frac{9}{40} + \frac{-27}{2800} \cdot {\varepsilon}^{2}\right) + \left(\mathsf{neg}\left(\frac{1}{2}\right)\right)} \]
      2. lower-fma.f64N/A

        \[\leadsto \color{blue}{\mathsf{fma}\left({\varepsilon}^{2}, \frac{9}{40} + \frac{-27}{2800} \cdot {\varepsilon}^{2}, \mathsf{neg}\left(\frac{1}{2}\right)\right)} \]
      3. unpow2N/A

        \[\leadsto \mathsf{fma}\left(\color{blue}{\varepsilon \cdot \varepsilon}, \frac{9}{40} + \frac{-27}{2800} \cdot {\varepsilon}^{2}, \mathsf{neg}\left(\frac{1}{2}\right)\right) \]
      4. lower-*.f64N/A

        \[\leadsto \mathsf{fma}\left(\color{blue}{\varepsilon \cdot \varepsilon}, \frac{9}{40} + \frac{-27}{2800} \cdot {\varepsilon}^{2}, \mathsf{neg}\left(\frac{1}{2}\right)\right) \]
      5. +-commutativeN/A

        \[\leadsto \mathsf{fma}\left(\varepsilon \cdot \varepsilon, \color{blue}{\frac{-27}{2800} \cdot {\varepsilon}^{2} + \frac{9}{40}}, \mathsf{neg}\left(\frac{1}{2}\right)\right) \]
      6. *-commutativeN/A

        \[\leadsto \mathsf{fma}\left(\varepsilon \cdot \varepsilon, \color{blue}{{\varepsilon}^{2} \cdot \frac{-27}{2800}} + \frac{9}{40}, \mathsf{neg}\left(\frac{1}{2}\right)\right) \]
      7. unpow2N/A

        \[\leadsto \mathsf{fma}\left(\varepsilon \cdot \varepsilon, \color{blue}{\left(\varepsilon \cdot \varepsilon\right)} \cdot \frac{-27}{2800} + \frac{9}{40}, \mathsf{neg}\left(\frac{1}{2}\right)\right) \]
      8. associate-*l*N/A

        \[\leadsto \mathsf{fma}\left(\varepsilon \cdot \varepsilon, \color{blue}{\varepsilon \cdot \left(\varepsilon \cdot \frac{-27}{2800}\right)} + \frac{9}{40}, \mathsf{neg}\left(\frac{1}{2}\right)\right) \]
      9. lower-fma.f64N/A

        \[\leadsto \mathsf{fma}\left(\varepsilon \cdot \varepsilon, \color{blue}{\mathsf{fma}\left(\varepsilon, \varepsilon \cdot \frac{-27}{2800}, \frac{9}{40}\right)}, \mathsf{neg}\left(\frac{1}{2}\right)\right) \]
      10. lower-*.f64N/A

        \[\leadsto \mathsf{fma}\left(\varepsilon \cdot \varepsilon, \mathsf{fma}\left(\varepsilon, \color{blue}{\varepsilon \cdot \frac{-27}{2800}}, \frac{9}{40}\right), \mathsf{neg}\left(\frac{1}{2}\right)\right) \]
      11. metadata-eval99.9

        \[\leadsto \mathsf{fma}\left(\varepsilon \cdot \varepsilon, \mathsf{fma}\left(\varepsilon, \varepsilon \cdot -0.009642857142857142, 0.225\right), \color{blue}{-0.5}\right) \]
    5. Applied rewrites99.9%

      \[\leadsto \color{blue}{\mathsf{fma}\left(\varepsilon \cdot \varepsilon, \mathsf{fma}\left(\varepsilon, \varepsilon \cdot -0.009642857142857142, 0.225\right), -0.5\right)} \]
    6. Add Preprocessing

    Alternative 4: 99.6% accurate, 18.2× speedup?

    \[\begin{array}{l} \\ \mathsf{fma}\left(0.225, \varepsilon \cdot \varepsilon, -0.5\right) \end{array} \]
    (FPCore (eps) :precision binary64 (fma 0.225 (* eps eps) -0.5))
    double code(double eps) {
    	return fma(0.225, (eps * eps), -0.5);
    }
    
    function code(eps)
    	return fma(0.225, Float64(eps * eps), -0.5)
    end
    
    code[eps_] := N[(0.225 * N[(eps * eps), $MachinePrecision] + -0.5), $MachinePrecision]
    
    \begin{array}{l}
    
    \\
    \mathsf{fma}\left(0.225, \varepsilon \cdot \varepsilon, -0.5\right)
    \end{array}
    
    Derivation
    1. Initial program 1.7%

      \[\frac{\varepsilon - \sin \varepsilon}{\varepsilon - \tan \varepsilon} \]
    2. Add Preprocessing
    3. Taylor expanded in eps around 0

      \[\leadsto \color{blue}{\frac{9}{40} \cdot {\varepsilon}^{2} - \frac{1}{2}} \]
    4. Step-by-step derivation
      1. sub-negN/A

        \[\leadsto \color{blue}{\frac{9}{40} \cdot {\varepsilon}^{2} + \left(\mathsf{neg}\left(\frac{1}{2}\right)\right)} \]
      2. lower-fma.f64N/A

        \[\leadsto \color{blue}{\mathsf{fma}\left(\frac{9}{40}, {\varepsilon}^{2}, \mathsf{neg}\left(\frac{1}{2}\right)\right)} \]
      3. unpow2N/A

        \[\leadsto \mathsf{fma}\left(\frac{9}{40}, \color{blue}{\varepsilon \cdot \varepsilon}, \mathsf{neg}\left(\frac{1}{2}\right)\right) \]
      4. lower-*.f64N/A

        \[\leadsto \mathsf{fma}\left(\frac{9}{40}, \color{blue}{\varepsilon \cdot \varepsilon}, \mathsf{neg}\left(\frac{1}{2}\right)\right) \]
      5. metadata-eval99.8

        \[\leadsto \mathsf{fma}\left(0.225, \varepsilon \cdot \varepsilon, \color{blue}{-0.5}\right) \]
    5. Applied rewrites99.8%

      \[\leadsto \color{blue}{\mathsf{fma}\left(0.225, \varepsilon \cdot \varepsilon, -0.5\right)} \]
    6. Add Preprocessing

    Alternative 5: 99.1% accurate, 218.0× speedup?

    \[\begin{array}{l} \\ -0.5 \end{array} \]
    (FPCore (eps) :precision binary64 -0.5)
    double code(double eps) {
    	return -0.5;
    }
    
    real(8) function code(eps)
        real(8), intent (in) :: eps
        code = -0.5d0
    end function
    
    public static double code(double eps) {
    	return -0.5;
    }
    
    def code(eps):
    	return -0.5
    
    function code(eps)
    	return -0.5
    end
    
    function tmp = code(eps)
    	tmp = -0.5;
    end
    
    code[eps_] := -0.5
    
    \begin{array}{l}
    
    \\
    -0.5
    \end{array}
    
    Derivation
    1. Initial program 1.7%

      \[\frac{\varepsilon - \sin \varepsilon}{\varepsilon - \tan \varepsilon} \]
    2. Add Preprocessing
    3. Taylor expanded in eps around 0

      \[\leadsto \color{blue}{\frac{-1}{2}} \]
    4. Step-by-step derivation
      1. Applied rewrites99.2%

        \[\leadsto \color{blue}{-0.5} \]
      2. Add Preprocessing

      Developer Target 1: 99.9% accurate, 2.1× speedup?

      \[\begin{array}{l} \\ \begin{array}{l} t_0 := \left(\left(\varepsilon \cdot \varepsilon\right) \cdot \varepsilon\right) \cdot \varepsilon\\ \left(\left(-0.5 + \frac{9 \cdot \left(\varepsilon \cdot \varepsilon\right)}{40}\right) + \frac{-27 \cdot t\_0}{2800}\right) + \frac{27 \cdot \left(\left(t\_0 \cdot \varepsilon\right) \cdot \varepsilon\right)}{112000} \end{array} \end{array} \]
      (FPCore (eps)
       :precision binary64
       (let* ((t_0 (* (* (* eps eps) eps) eps)))
         (+
          (+ (+ -0.5 (/ (* 9.0 (* eps eps)) 40.0)) (/ (* -27.0 t_0) 2800.0))
          (/ (* 27.0 (* (* t_0 eps) eps)) 112000.0))))
      double code(double eps) {
      	double t_0 = ((eps * eps) * eps) * eps;
      	return ((-0.5 + ((9.0 * (eps * eps)) / 40.0)) + ((-27.0 * t_0) / 2800.0)) + ((27.0 * ((t_0 * eps) * eps)) / 112000.0);
      }
      
      real(8) function code(eps)
          real(8), intent (in) :: eps
          real(8) :: t_0
          t_0 = ((eps * eps) * eps) * eps
          code = (((-0.5d0) + ((9.0d0 * (eps * eps)) / 40.0d0)) + (((-27.0d0) * t_0) / 2800.0d0)) + ((27.0d0 * ((t_0 * eps) * eps)) / 112000.0d0)
      end function
      
      public static double code(double eps) {
      	double t_0 = ((eps * eps) * eps) * eps;
      	return ((-0.5 + ((9.0 * (eps * eps)) / 40.0)) + ((-27.0 * t_0) / 2800.0)) + ((27.0 * ((t_0 * eps) * eps)) / 112000.0);
      }
      
      def code(eps):
      	t_0 = ((eps * eps) * eps) * eps
      	return ((-0.5 + ((9.0 * (eps * eps)) / 40.0)) + ((-27.0 * t_0) / 2800.0)) + ((27.0 * ((t_0 * eps) * eps)) / 112000.0)
      
      function code(eps)
      	t_0 = Float64(Float64(Float64(eps * eps) * eps) * eps)
      	return Float64(Float64(Float64(-0.5 + Float64(Float64(9.0 * Float64(eps * eps)) / 40.0)) + Float64(Float64(-27.0 * t_0) / 2800.0)) + Float64(Float64(27.0 * Float64(Float64(t_0 * eps) * eps)) / 112000.0))
      end
      
      function tmp = code(eps)
      	t_0 = ((eps * eps) * eps) * eps;
      	tmp = ((-0.5 + ((9.0 * (eps * eps)) / 40.0)) + ((-27.0 * t_0) / 2800.0)) + ((27.0 * ((t_0 * eps) * eps)) / 112000.0);
      end
      
      code[eps_] := Block[{t$95$0 = N[(N[(N[(eps * eps), $MachinePrecision] * eps), $MachinePrecision] * eps), $MachinePrecision]}, N[(N[(N[(-0.5 + N[(N[(9.0 * N[(eps * eps), $MachinePrecision]), $MachinePrecision] / 40.0), $MachinePrecision]), $MachinePrecision] + N[(N[(-27.0 * t$95$0), $MachinePrecision] / 2800.0), $MachinePrecision]), $MachinePrecision] + N[(N[(27.0 * N[(N[(t$95$0 * eps), $MachinePrecision] * eps), $MachinePrecision]), $MachinePrecision] / 112000.0), $MachinePrecision]), $MachinePrecision]]
      
      \begin{array}{l}
      
      \\
      \begin{array}{l}
      t_0 := \left(\left(\varepsilon \cdot \varepsilon\right) \cdot \varepsilon\right) \cdot \varepsilon\\
      \left(\left(-0.5 + \frac{9 \cdot \left(\varepsilon \cdot \varepsilon\right)}{40}\right) + \frac{-27 \cdot t\_0}{2800}\right) + \frac{27 \cdot \left(\left(t\_0 \cdot \varepsilon\right) \cdot \varepsilon\right)}{112000}
      \end{array}
      \end{array}
      

      Developer Target 2: 99.6% accurate, 15.6× speedup?

      \[\begin{array}{l} \\ \left(0.225 \cdot \varepsilon\right) \cdot \varepsilon - 0.5 \end{array} \]
      (FPCore (eps) :precision binary64 (- (* (* 0.225 eps) eps) 0.5))
      double code(double eps) {
      	return ((0.225 * eps) * eps) - 0.5;
      }
      
      real(8) function code(eps)
          real(8), intent (in) :: eps
          code = ((0.225d0 * eps) * eps) - 0.5d0
      end function
      
      public static double code(double eps) {
      	return ((0.225 * eps) * eps) - 0.5;
      }
      
      def code(eps):
      	return ((0.225 * eps) * eps) - 0.5
      
      function code(eps)
      	return Float64(Float64(Float64(0.225 * eps) * eps) - 0.5)
      end
      
      function tmp = code(eps)
      	tmp = ((0.225 * eps) * eps) - 0.5;
      end
      
      code[eps_] := N[(N[(N[(0.225 * eps), $MachinePrecision] * eps), $MachinePrecision] - 0.5), $MachinePrecision]
      
      \begin{array}{l}
      
      \\
      \left(0.225 \cdot \varepsilon\right) \cdot \varepsilon - 0.5
      \end{array}
      

      Reproduce

      ?
      herbie shell --seed 2024232 
      (FPCore (eps)
        :name "sintan (problem 3.4.5)"
        :precision binary64
        :pre (and (<= -0.4 eps) (<= eps 0.4))
      
        :alt
        (! :herbie-platform default (+ -1/2 (/ (* 9 (* eps eps)) 40) (/ (* -27 (* eps eps eps eps)) 2800) (/ (* 27 (* eps eps eps eps eps eps)) 112000)))
      
        :alt
        (! :herbie-platform default (- (* 9/40 eps eps) 1/2))
      
        (/ (- eps (sin eps)) (- eps (tan eps))))