expfmod (used to be hard to sample)

Percentage Accurate: 7.2% → 62.3%
Time: 20.9s
Alternatives: 4
Speedup: 5.0×

Specification

?
\[\begin{array}{l} \\ \left(\left(e^{x}\right) \bmod \left(\sqrt{\cos x}\right)\right) \cdot e^{-x} \end{array} \]
(FPCore (x) :precision binary64 (* (fmod (exp x) (sqrt (cos x))) (exp (- x))))
double code(double x) {
	return fmod(exp(x), sqrt(cos(x))) * exp(-x);
}
real(8) function code(x)
    real(8), intent (in) :: x
    code = mod(exp(x), sqrt(cos(x))) * exp(-x)
end function
def code(x):
	return math.fmod(math.exp(x), math.sqrt(math.cos(x))) * math.exp(-x)
function code(x)
	return Float64(rem(exp(x), sqrt(cos(x))) * exp(Float64(-x)))
end
code[x_] := N[(N[With[{TMP1 = N[Exp[x], $MachinePrecision], TMP2 = N[Sqrt[N[Cos[x], $MachinePrecision]], $MachinePrecision]}, Mod[Abs[TMP1], Abs[TMP2]] * Sign[TMP1]], $MachinePrecision] * N[Exp[(-x)], $MachinePrecision]), $MachinePrecision]
\begin{array}{l}

\\
\left(\left(e^{x}\right) \bmod \left(\sqrt{\cos x}\right)\right) \cdot e^{-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 4 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: 7.2% accurate, 1.0× speedup?

\[\begin{array}{l} \\ \left(\left(e^{x}\right) \bmod \left(\sqrt{\cos x}\right)\right) \cdot e^{-x} \end{array} \]
(FPCore (x) :precision binary64 (* (fmod (exp x) (sqrt (cos x))) (exp (- x))))
double code(double x) {
	return fmod(exp(x), sqrt(cos(x))) * exp(-x);
}
real(8) function code(x)
    real(8), intent (in) :: x
    code = mod(exp(x), sqrt(cos(x))) * exp(-x)
end function
def code(x):
	return math.fmod(math.exp(x), math.sqrt(math.cos(x))) * math.exp(-x)
function code(x)
	return Float64(rem(exp(x), sqrt(cos(x))) * exp(Float64(-x)))
end
code[x_] := N[(N[With[{TMP1 = N[Exp[x], $MachinePrecision], TMP2 = N[Sqrt[N[Cos[x], $MachinePrecision]], $MachinePrecision]}, Mod[Abs[TMP1], Abs[TMP2]] * Sign[TMP1]], $MachinePrecision] * N[Exp[(-x)], $MachinePrecision]), $MachinePrecision]
\begin{array}{l}

\\
\left(\left(e^{x}\right) \bmod \left(\sqrt{\cos x}\right)\right) \cdot e^{-x}
\end{array}

Alternative 1: 62.3% accurate, 0.5× speedup?

\[\begin{array}{l} \\ \begin{array}{l} t_0 := \sqrt{\cos x}\\ \mathbf{if}\;x \leq 0.2:\\ \;\;\;\;\frac{\left(\left(e^{x}\right) \bmod \left(t\_0 \cdot 0.6666666666666666 + \log \left(\sqrt[3]{e^{t\_0}}\right)\right)\right)}{e^{x}}\\ \mathbf{else}:\\ \;\;\;\;e^{-x}\\ \end{array} \end{array} \]
(FPCore (x)
 :precision binary64
 (let* ((t_0 (sqrt (cos x))))
   (if (<= x 0.2)
     (/
      (fmod (exp x) (+ (* t_0 0.6666666666666666) (log (cbrt (exp t_0)))))
      (exp x))
     (exp (- x)))))
double code(double x) {
	double t_0 = sqrt(cos(x));
	double tmp;
	if (x <= 0.2) {
		tmp = fmod(exp(x), ((t_0 * 0.6666666666666666) + log(cbrt(exp(t_0))))) / exp(x);
	} else {
		tmp = exp(-x);
	}
	return tmp;
}
function code(x)
	t_0 = sqrt(cos(x))
	tmp = 0.0
	if (x <= 0.2)
		tmp = Float64(rem(exp(x), Float64(Float64(t_0 * 0.6666666666666666) + log(cbrt(exp(t_0))))) / exp(x));
	else
		tmp = exp(Float64(-x));
	end
	return tmp
end
code[x_] := Block[{t$95$0 = N[Sqrt[N[Cos[x], $MachinePrecision]], $MachinePrecision]}, If[LessEqual[x, 0.2], N[(N[With[{TMP1 = N[Exp[x], $MachinePrecision], TMP2 = N[(N[(t$95$0 * 0.6666666666666666), $MachinePrecision] + N[Log[N[Power[N[Exp[t$95$0], $MachinePrecision], 1/3], $MachinePrecision]], $MachinePrecision]), $MachinePrecision]}, Mod[Abs[TMP1], Abs[TMP2]] * Sign[TMP1]], $MachinePrecision] / N[Exp[x], $MachinePrecision]), $MachinePrecision], N[Exp[(-x)], $MachinePrecision]]]
\begin{array}{l}

\\
\begin{array}{l}
t_0 := \sqrt{\cos x}\\
\mathbf{if}\;x \leq 0.2:\\
\;\;\;\;\frac{\left(\left(e^{x}\right) \bmod \left(t\_0 \cdot 0.6666666666666666 + \log \left(\sqrt[3]{e^{t\_0}}\right)\right)\right)}{e^{x}}\\

\mathbf{else}:\\
\;\;\;\;e^{-x}\\


\end{array}
\end{array}
Derivation
  1. Split input into 2 regimes
  2. if x < 0.20000000000000001

    1. Initial program 9.7%

      \[\left(\left(e^{x}\right) \bmod \left(\sqrt{\cos x}\right)\right) \cdot e^{-x} \]
    2. Step-by-step derivation
      1. /-rgt-identity9.7%

        \[\leadsto \color{blue}{\frac{\left(\left(e^{x}\right) \bmod \left(\sqrt{\cos x}\right)\right)}{1}} \cdot e^{-x} \]
      2. associate-/r/9.7%

        \[\leadsto \color{blue}{\frac{\left(\left(e^{x}\right) \bmod \left(\sqrt{\cos x}\right)\right)}{\frac{1}{e^{-x}}}} \]
      3. exp-neg9.7%

        \[\leadsto \frac{\left(\left(e^{x}\right) \bmod \left(\sqrt{\cos x}\right)\right)}{\color{blue}{e^{-\left(-x\right)}}} \]
      4. remove-double-neg9.7%

        \[\leadsto \frac{\left(\left(e^{x}\right) \bmod \left(\sqrt{\cos x}\right)\right)}{e^{\color{blue}{x}}} \]
    3. Simplified9.7%

      \[\leadsto \color{blue}{\frac{\left(\left(e^{x}\right) \bmod \left(\sqrt{\cos x}\right)\right)}{e^{x}}} \]
    4. Add Preprocessing
    5. Step-by-step derivation
      1. add-log-exp9.7%

        \[\leadsto \frac{\left(\left(e^{x}\right) \bmod \color{blue}{\log \left(e^{\sqrt{\cos x}}\right)}\right)}{e^{x}} \]
      2. add-cube-cbrt53.7%

        \[\leadsto \frac{\left(\left(e^{x}\right) \bmod \log \color{blue}{\left(\left(\sqrt[3]{e^{\sqrt{\cos x}}} \cdot \sqrt[3]{e^{\sqrt{\cos x}}}\right) \cdot \sqrt[3]{e^{\sqrt{\cos x}}}\right)}\right)}{e^{x}} \]
      3. log-prod53.7%

        \[\leadsto \frac{\left(\left(e^{x}\right) \bmod \color{blue}{\left(\log \left(\sqrt[3]{e^{\sqrt{\cos x}}} \cdot \sqrt[3]{e^{\sqrt{\cos x}}}\right) + \log \left(\sqrt[3]{e^{\sqrt{\cos x}}}\right)\right)}\right)}{e^{x}} \]
      4. pow253.7%

        \[\leadsto \frac{\left(\left(e^{x}\right) \bmod \left(\log \color{blue}{\left({\left(\sqrt[3]{e^{\sqrt{\cos x}}}\right)}^{2}\right)} + \log \left(\sqrt[3]{e^{\sqrt{\cos x}}}\right)\right)\right)}{e^{x}} \]
    6. Applied egg-rr53.7%

      \[\leadsto \frac{\left(\left(e^{x}\right) \bmod \color{blue}{\left(\log \left({\left(\sqrt[3]{e^{\sqrt{\cos x}}}\right)}^{2}\right) + \log \left(\sqrt[3]{e^{\sqrt{\cos x}}}\right)\right)}\right)}{e^{x}} \]
    7. Step-by-step derivation
      1. unpow253.7%

        \[\leadsto \frac{\left(\left(e^{x}\right) \bmod \left(\log \color{blue}{\left(\sqrt[3]{e^{\sqrt{\cos x}}} \cdot \sqrt[3]{e^{\sqrt{\cos x}}}\right)} + \log \left(\sqrt[3]{e^{\sqrt{\cos x}}}\right)\right)\right)}{e^{x}} \]
      2. log-prod53.7%

        \[\leadsto \frac{\left(\left(e^{x}\right) \bmod \left(\color{blue}{\left(\log \left(\sqrt[3]{e^{\sqrt{\cos x}}}\right) + \log \left(\sqrt[3]{e^{\sqrt{\cos x}}}\right)\right)} + \log \left(\sqrt[3]{e^{\sqrt{\cos x}}}\right)\right)\right)}{e^{x}} \]
      3. pow1/353.7%

        \[\leadsto \frac{\left(\left(e^{x}\right) \bmod \left(\left(\log \color{blue}{\left({\left(e^{\sqrt{\cos x}}\right)}^{0.3333333333333333}\right)} + \log \left(\sqrt[3]{e^{\sqrt{\cos x}}}\right)\right) + \log \left(\sqrt[3]{e^{\sqrt{\cos x}}}\right)\right)\right)}{e^{x}} \]
      4. log-pow53.8%

        \[\leadsto \frac{\left(\left(e^{x}\right) \bmod \left(\left(\color{blue}{0.3333333333333333 \cdot \log \left(e^{\sqrt{\cos x}}\right)} + \log \left(\sqrt[3]{e^{\sqrt{\cos x}}}\right)\right) + \log \left(\sqrt[3]{e^{\sqrt{\cos x}}}\right)\right)\right)}{e^{x}} \]
      5. add-log-exp53.8%

        \[\leadsto \frac{\left(\left(e^{x}\right) \bmod \left(\left(0.3333333333333333 \cdot \color{blue}{\sqrt{\cos x}} + \log \left(\sqrt[3]{e^{\sqrt{\cos x}}}\right)\right) + \log \left(\sqrt[3]{e^{\sqrt{\cos x}}}\right)\right)\right)}{e^{x}} \]
      6. pow1/353.8%

        \[\leadsto \frac{\left(\left(e^{x}\right) \bmod \left(\left(0.3333333333333333 \cdot \sqrt{\cos x} + \log \color{blue}{\left({\left(e^{\sqrt{\cos x}}\right)}^{0.3333333333333333}\right)}\right) + \log \left(\sqrt[3]{e^{\sqrt{\cos x}}}\right)\right)\right)}{e^{x}} \]
      7. log-pow53.8%

        \[\leadsto \frac{\left(\left(e^{x}\right) \bmod \left(\left(0.3333333333333333 \cdot \sqrt{\cos x} + \color{blue}{0.3333333333333333 \cdot \log \left(e^{\sqrt{\cos x}}\right)}\right) + \log \left(\sqrt[3]{e^{\sqrt{\cos x}}}\right)\right)\right)}{e^{x}} \]
      8. add-log-exp53.8%

        \[\leadsto \frac{\left(\left(e^{x}\right) \bmod \left(\left(0.3333333333333333 \cdot \sqrt{\cos x} + 0.3333333333333333 \cdot \color{blue}{\sqrt{\cos x}}\right) + \log \left(\sqrt[3]{e^{\sqrt{\cos x}}}\right)\right)\right)}{e^{x}} \]
    8. Applied egg-rr53.8%

      \[\leadsto \frac{\left(\left(e^{x}\right) \bmod \left(\color{blue}{\left(0.3333333333333333 \cdot \sqrt{\cos x} + 0.3333333333333333 \cdot \sqrt{\cos x}\right)} + \log \left(\sqrt[3]{e^{\sqrt{\cos x}}}\right)\right)\right)}{e^{x}} \]
    9. Step-by-step derivation
      1. distribute-rgt-out53.8%

        \[\leadsto \frac{\left(\left(e^{x}\right) \bmod \left(\color{blue}{\sqrt{\cos x} \cdot \left(0.3333333333333333 + 0.3333333333333333\right)} + \log \left(\sqrt[3]{e^{\sqrt{\cos x}}}\right)\right)\right)}{e^{x}} \]
      2. metadata-eval53.8%

        \[\leadsto \frac{\left(\left(e^{x}\right) \bmod \left(\sqrt{\cos x} \cdot \color{blue}{0.6666666666666666} + \log \left(\sqrt[3]{e^{\sqrt{\cos x}}}\right)\right)\right)}{e^{x}} \]
    10. Simplified53.8%

      \[\leadsto \frac{\left(\left(e^{x}\right) \bmod \left(\color{blue}{\sqrt{\cos x} \cdot 0.6666666666666666} + \log \left(\sqrt[3]{e^{\sqrt{\cos x}}}\right)\right)\right)}{e^{x}} \]

    if 0.20000000000000001 < x

    1. Initial program 0.0%

      \[\left(\left(e^{x}\right) \bmod \left(\sqrt{\cos x}\right)\right) \cdot e^{-x} \]
    2. Step-by-step derivation
      1. /-rgt-identity0.0%

        \[\leadsto \color{blue}{\frac{\left(\left(e^{x}\right) \bmod \left(\sqrt{\cos x}\right)\right)}{1}} \cdot e^{-x} \]
      2. associate-/r/0.0%

        \[\leadsto \color{blue}{\frac{\left(\left(e^{x}\right) \bmod \left(\sqrt{\cos x}\right)\right)}{\frac{1}{e^{-x}}}} \]
      3. exp-neg0.0%

        \[\leadsto \frac{\left(\left(e^{x}\right) \bmod \left(\sqrt{\cos x}\right)\right)}{\color{blue}{e^{-\left(-x\right)}}} \]
      4. remove-double-neg0.0%

        \[\leadsto \frac{\left(\left(e^{x}\right) \bmod \left(\sqrt{\cos x}\right)\right)}{e^{\color{blue}{x}}} \]
    3. Simplified0.0%

      \[\leadsto \color{blue}{\frac{\left(\left(e^{x}\right) \bmod \left(\sqrt{\cos x}\right)\right)}{e^{x}}} \]
    4. Add Preprocessing
    5. Step-by-step derivation
      1. add-cbrt-cube0.0%

        \[\leadsto \color{blue}{\sqrt[3]{\left(\frac{\left(\left(e^{x}\right) \bmod \left(\sqrt{\cos x}\right)\right)}{e^{x}} \cdot \frac{\left(\left(e^{x}\right) \bmod \left(\sqrt{\cos x}\right)\right)}{e^{x}}\right) \cdot \frac{\left(\left(e^{x}\right) \bmod \left(\sqrt{\cos x}\right)\right)}{e^{x}}}} \]
      2. pow1/30.0%

        \[\leadsto \color{blue}{{\left(\left(\frac{\left(\left(e^{x}\right) \bmod \left(\sqrt{\cos x}\right)\right)}{e^{x}} \cdot \frac{\left(\left(e^{x}\right) \bmod \left(\sqrt{\cos x}\right)\right)}{e^{x}}\right) \cdot \frac{\left(\left(e^{x}\right) \bmod \left(\sqrt{\cos x}\right)\right)}{e^{x}}\right)}^{0.3333333333333333}} \]
      3. pow-to-exp0.0%

        \[\leadsto \color{blue}{e^{\log \left(\left(\frac{\left(\left(e^{x}\right) \bmod \left(\sqrt{\cos x}\right)\right)}{e^{x}} \cdot \frac{\left(\left(e^{x}\right) \bmod \left(\sqrt{\cos x}\right)\right)}{e^{x}}\right) \cdot \frac{\left(\left(e^{x}\right) \bmod \left(\sqrt{\cos x}\right)\right)}{e^{x}}\right) \cdot 0.3333333333333333}} \]
      4. pow30.0%

        \[\leadsto e^{\log \color{blue}{\left({\left(\frac{\left(\left(e^{x}\right) \bmod \left(\sqrt{\cos x}\right)\right)}{e^{x}}\right)}^{3}\right)} \cdot 0.3333333333333333} \]
      5. log-pow0.0%

        \[\leadsto e^{\color{blue}{\left(3 \cdot \log \left(\frac{\left(\left(e^{x}\right) \bmod \left(\sqrt{\cos x}\right)\right)}{e^{x}}\right)\right)} \cdot 0.3333333333333333} \]
      6. log-div0.0%

        \[\leadsto e^{\left(3 \cdot \color{blue}{\left(\log \left(\left(e^{x}\right) \bmod \left(\sqrt{\cos x}\right)\right) - \log \left(e^{x}\right)\right)}\right) \cdot 0.3333333333333333} \]
      7. add-log-exp0.0%

        \[\leadsto e^{\left(3 \cdot \left(\log \left(\left(e^{x}\right) \bmod \left(\sqrt{\cos x}\right)\right) - \color{blue}{x}\right)\right) \cdot 0.3333333333333333} \]
    6. Applied egg-rr0.0%

      \[\leadsto \color{blue}{e^{\left(3 \cdot \left(\log \left(\left(e^{x}\right) \bmod \left(\sqrt{\cos x}\right)\right) - x\right)\right) \cdot 0.3333333333333333}} \]
    7. Taylor expanded in x around inf 100.0%

      \[\leadsto e^{\color{blue}{\left(-3 \cdot x\right)} \cdot 0.3333333333333333} \]
    8. Step-by-step derivation
      1. *-commutative100.0%

        \[\leadsto e^{\color{blue}{\left(x \cdot -3\right)} \cdot 0.3333333333333333} \]
    9. Simplified100.0%

      \[\leadsto e^{\color{blue}{\left(x \cdot -3\right)} \cdot 0.3333333333333333} \]
    10. Taylor expanded in x around 0 100.0%

      \[\leadsto e^{\color{blue}{-1 \cdot x}} \]
    11. Step-by-step derivation
      1. neg-mul-1100.0%

        \[\leadsto e^{\color{blue}{-x}} \]
    12. Simplified100.0%

      \[\leadsto e^{\color{blue}{-x}} \]
  3. Recombined 2 regimes into one program.
  4. Add Preprocessing

Alternative 2: 61.5% accurate, 1.6× speedup?

\[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;x \leq -2 \cdot 10^{-16}:\\ \;\;\;\;\frac{\left(\left(e^{x}\right) \bmod 1\right)}{e^{x}}\\ \mathbf{else}:\\ \;\;\;\;e^{-x}\\ \end{array} \end{array} \]
(FPCore (x)
 :precision binary64
 (if (<= x -2e-16) (/ (fmod (exp x) 1.0) (exp x)) (exp (- x))))
double code(double x) {
	double tmp;
	if (x <= -2e-16) {
		tmp = fmod(exp(x), 1.0) / exp(x);
	} else {
		tmp = exp(-x);
	}
	return tmp;
}
real(8) function code(x)
    real(8), intent (in) :: x
    real(8) :: tmp
    if (x <= (-2d-16)) then
        tmp = mod(exp(x), 1.0d0) / exp(x)
    else
        tmp = exp(-x)
    end if
    code = tmp
end function
def code(x):
	tmp = 0
	if x <= -2e-16:
		tmp = math.fmod(math.exp(x), 1.0) / math.exp(x)
	else:
		tmp = math.exp(-x)
	return tmp
function code(x)
	tmp = 0.0
	if (x <= -2e-16)
		tmp = Float64(rem(exp(x), 1.0) / exp(x));
	else
		tmp = exp(Float64(-x));
	end
	return tmp
end
code[x_] := If[LessEqual[x, -2e-16], N[(N[With[{TMP1 = N[Exp[x], $MachinePrecision], TMP2 = 1.0}, Mod[Abs[TMP1], Abs[TMP2]] * Sign[TMP1]], $MachinePrecision] / N[Exp[x], $MachinePrecision]), $MachinePrecision], N[Exp[(-x)], $MachinePrecision]]
\begin{array}{l}

\\
\begin{array}{l}
\mathbf{if}\;x \leq -2 \cdot 10^{-16}:\\
\;\;\;\;\frac{\left(\left(e^{x}\right) \bmod 1\right)}{e^{x}}\\

\mathbf{else}:\\
\;\;\;\;e^{-x}\\


\end{array}
\end{array}
Derivation
  1. Split input into 2 regimes
  2. if x < -2e-16

    1. Initial program 99.7%

      \[\left(\left(e^{x}\right) \bmod \left(\sqrt{\cos x}\right)\right) \cdot e^{-x} \]
    2. Step-by-step derivation
      1. /-rgt-identity99.7%

        \[\leadsto \color{blue}{\frac{\left(\left(e^{x}\right) \bmod \left(\sqrt{\cos x}\right)\right)}{1}} \cdot e^{-x} \]
      2. associate-/r/99.5%

        \[\leadsto \color{blue}{\frac{\left(\left(e^{x}\right) \bmod \left(\sqrt{\cos x}\right)\right)}{\frac{1}{e^{-x}}}} \]
      3. exp-neg100.0%

        \[\leadsto \frac{\left(\left(e^{x}\right) \bmod \left(\sqrt{\cos x}\right)\right)}{\color{blue}{e^{-\left(-x\right)}}} \]
      4. remove-double-neg100.0%

        \[\leadsto \frac{\left(\left(e^{x}\right) \bmod \left(\sqrt{\cos x}\right)\right)}{e^{\color{blue}{x}}} \]
    3. Simplified100.0%

      \[\leadsto \color{blue}{\frac{\left(\left(e^{x}\right) \bmod \left(\sqrt{\cos x}\right)\right)}{e^{x}}} \]
    4. Add Preprocessing
    5. Taylor expanded in x around 0 100.0%

      \[\leadsto \frac{\left(\left(e^{x}\right) \bmod \color{blue}{1}\right)}{e^{x}} \]

    if -2e-16 < x

    1. Initial program 4.5%

      \[\left(\left(e^{x}\right) \bmod \left(\sqrt{\cos x}\right)\right) \cdot e^{-x} \]
    2. Step-by-step derivation
      1. /-rgt-identity4.5%

        \[\leadsto \color{blue}{\frac{\left(\left(e^{x}\right) \bmod \left(\sqrt{\cos x}\right)\right)}{1}} \cdot e^{-x} \]
      2. associate-/r/4.5%

        \[\leadsto \color{blue}{\frac{\left(\left(e^{x}\right) \bmod \left(\sqrt{\cos x}\right)\right)}{\frac{1}{e^{-x}}}} \]
      3. exp-neg4.5%

        \[\leadsto \frac{\left(\left(e^{x}\right) \bmod \left(\sqrt{\cos x}\right)\right)}{\color{blue}{e^{-\left(-x\right)}}} \]
      4. remove-double-neg4.5%

        \[\leadsto \frac{\left(\left(e^{x}\right) \bmod \left(\sqrt{\cos x}\right)\right)}{e^{\color{blue}{x}}} \]
    3. Simplified4.5%

      \[\leadsto \color{blue}{\frac{\left(\left(e^{x}\right) \bmod \left(\sqrt{\cos x}\right)\right)}{e^{x}}} \]
    4. Add Preprocessing
    5. Step-by-step derivation
      1. add-cbrt-cube4.5%

        \[\leadsto \color{blue}{\sqrt[3]{\left(\frac{\left(\left(e^{x}\right) \bmod \left(\sqrt{\cos x}\right)\right)}{e^{x}} \cdot \frac{\left(\left(e^{x}\right) \bmod \left(\sqrt{\cos x}\right)\right)}{e^{x}}\right) \cdot \frac{\left(\left(e^{x}\right) \bmod \left(\sqrt{\cos x}\right)\right)}{e^{x}}}} \]
      2. pow1/34.5%

        \[\leadsto \color{blue}{{\left(\left(\frac{\left(\left(e^{x}\right) \bmod \left(\sqrt{\cos x}\right)\right)}{e^{x}} \cdot \frac{\left(\left(e^{x}\right) \bmod \left(\sqrt{\cos x}\right)\right)}{e^{x}}\right) \cdot \frac{\left(\left(e^{x}\right) \bmod \left(\sqrt{\cos x}\right)\right)}{e^{x}}\right)}^{0.3333333333333333}} \]
      3. pow-to-exp4.5%

        \[\leadsto \color{blue}{e^{\log \left(\left(\frac{\left(\left(e^{x}\right) \bmod \left(\sqrt{\cos x}\right)\right)}{e^{x}} \cdot \frac{\left(\left(e^{x}\right) \bmod \left(\sqrt{\cos x}\right)\right)}{e^{x}}\right) \cdot \frac{\left(\left(e^{x}\right) \bmod \left(\sqrt{\cos x}\right)\right)}{e^{x}}\right) \cdot 0.3333333333333333}} \]
      4. pow34.5%

        \[\leadsto e^{\log \color{blue}{\left({\left(\frac{\left(\left(e^{x}\right) \bmod \left(\sqrt{\cos x}\right)\right)}{e^{x}}\right)}^{3}\right)} \cdot 0.3333333333333333} \]
      5. log-pow4.5%

        \[\leadsto e^{\color{blue}{\left(3 \cdot \log \left(\frac{\left(\left(e^{x}\right) \bmod \left(\sqrt{\cos x}\right)\right)}{e^{x}}\right)\right)} \cdot 0.3333333333333333} \]
      6. log-div4.5%

        \[\leadsto e^{\left(3 \cdot \color{blue}{\left(\log \left(\left(e^{x}\right) \bmod \left(\sqrt{\cos x}\right)\right) - \log \left(e^{x}\right)\right)}\right) \cdot 0.3333333333333333} \]
      7. add-log-exp4.5%

        \[\leadsto e^{\left(3 \cdot \left(\log \left(\left(e^{x}\right) \bmod \left(\sqrt{\cos x}\right)\right) - \color{blue}{x}\right)\right) \cdot 0.3333333333333333} \]
    6. Applied egg-rr4.5%

      \[\leadsto \color{blue}{e^{\left(3 \cdot \left(\log \left(\left(e^{x}\right) \bmod \left(\sqrt{\cos x}\right)\right) - x\right)\right) \cdot 0.3333333333333333}} \]
    7. Taylor expanded in x around inf 60.5%

      \[\leadsto e^{\color{blue}{\left(-3 \cdot x\right)} \cdot 0.3333333333333333} \]
    8. Step-by-step derivation
      1. *-commutative60.5%

        \[\leadsto e^{\color{blue}{\left(x \cdot -3\right)} \cdot 0.3333333333333333} \]
    9. Simplified60.5%

      \[\leadsto e^{\color{blue}{\left(x \cdot -3\right)} \cdot 0.3333333333333333} \]
    10. Taylor expanded in x around 0 60.5%

      \[\leadsto e^{\color{blue}{-1 \cdot x}} \]
    11. Step-by-step derivation
      1. neg-mul-160.5%

        \[\leadsto e^{\color{blue}{-x}} \]
    12. Simplified60.5%

      \[\leadsto e^{\color{blue}{-x}} \]
  3. Recombined 2 regimes into one program.
  4. Add Preprocessing

Alternative 3: 60.3% accurate, 5.0× speedup?

\[\begin{array}{l} \\ e^{-x} \end{array} \]
(FPCore (x) :precision binary64 (exp (- x)))
double code(double x) {
	return exp(-x);
}
real(8) function code(x)
    real(8), intent (in) :: x
    code = exp(-x)
end function
public static double code(double x) {
	return Math.exp(-x);
}
def code(x):
	return math.exp(-x)
function code(x)
	return exp(Float64(-x))
end
function tmp = code(x)
	tmp = exp(-x);
end
code[x_] := N[Exp[(-x)], $MachinePrecision]
\begin{array}{l}

\\
e^{-x}
\end{array}
Derivation
  1. Initial program 7.8%

    \[\left(\left(e^{x}\right) \bmod \left(\sqrt{\cos x}\right)\right) \cdot e^{-x} \]
  2. Step-by-step derivation
    1. /-rgt-identity7.8%

      \[\leadsto \color{blue}{\frac{\left(\left(e^{x}\right) \bmod \left(\sqrt{\cos x}\right)\right)}{1}} \cdot e^{-x} \]
    2. associate-/r/7.8%

      \[\leadsto \color{blue}{\frac{\left(\left(e^{x}\right) \bmod \left(\sqrt{\cos x}\right)\right)}{\frac{1}{e^{-x}}}} \]
    3. exp-neg7.8%

      \[\leadsto \frac{\left(\left(e^{x}\right) \bmod \left(\sqrt{\cos x}\right)\right)}{\color{blue}{e^{-\left(-x\right)}}} \]
    4. remove-double-neg7.8%

      \[\leadsto \frac{\left(\left(e^{x}\right) \bmod \left(\sqrt{\cos x}\right)\right)}{e^{\color{blue}{x}}} \]
  3. Simplified7.8%

    \[\leadsto \color{blue}{\frac{\left(\left(e^{x}\right) \bmod \left(\sqrt{\cos x}\right)\right)}{e^{x}}} \]
  4. Add Preprocessing
  5. Step-by-step derivation
    1. add-cbrt-cube7.8%

      \[\leadsto \color{blue}{\sqrt[3]{\left(\frac{\left(\left(e^{x}\right) \bmod \left(\sqrt{\cos x}\right)\right)}{e^{x}} \cdot \frac{\left(\left(e^{x}\right) \bmod \left(\sqrt{\cos x}\right)\right)}{e^{x}}\right) \cdot \frac{\left(\left(e^{x}\right) \bmod \left(\sqrt{\cos x}\right)\right)}{e^{x}}}} \]
    2. pow1/37.8%

      \[\leadsto \color{blue}{{\left(\left(\frac{\left(\left(e^{x}\right) \bmod \left(\sqrt{\cos x}\right)\right)}{e^{x}} \cdot \frac{\left(\left(e^{x}\right) \bmod \left(\sqrt{\cos x}\right)\right)}{e^{x}}\right) \cdot \frac{\left(\left(e^{x}\right) \bmod \left(\sqrt{\cos x}\right)\right)}{e^{x}}\right)}^{0.3333333333333333}} \]
    3. pow-to-exp7.8%

      \[\leadsto \color{blue}{e^{\log \left(\left(\frac{\left(\left(e^{x}\right) \bmod \left(\sqrt{\cos x}\right)\right)}{e^{x}} \cdot \frac{\left(\left(e^{x}\right) \bmod \left(\sqrt{\cos x}\right)\right)}{e^{x}}\right) \cdot \frac{\left(\left(e^{x}\right) \bmod \left(\sqrt{\cos x}\right)\right)}{e^{x}}\right) \cdot 0.3333333333333333}} \]
    4. pow37.8%

      \[\leadsto e^{\log \color{blue}{\left({\left(\frac{\left(\left(e^{x}\right) \bmod \left(\sqrt{\cos x}\right)\right)}{e^{x}}\right)}^{3}\right)} \cdot 0.3333333333333333} \]
    5. log-pow7.8%

      \[\leadsto e^{\color{blue}{\left(3 \cdot \log \left(\frac{\left(\left(e^{x}\right) \bmod \left(\sqrt{\cos x}\right)\right)}{e^{x}}\right)\right)} \cdot 0.3333333333333333} \]
    6. log-div7.8%

      \[\leadsto e^{\left(3 \cdot \color{blue}{\left(\log \left(\left(e^{x}\right) \bmod \left(\sqrt{\cos x}\right)\right) - \log \left(e^{x}\right)\right)}\right) \cdot 0.3333333333333333} \]
    7. add-log-exp7.8%

      \[\leadsto e^{\left(3 \cdot \left(\log \left(\left(e^{x}\right) \bmod \left(\sqrt{\cos x}\right)\right) - \color{blue}{x}\right)\right) \cdot 0.3333333333333333} \]
  6. Applied egg-rr7.8%

    \[\leadsto \color{blue}{e^{\left(3 \cdot \left(\log \left(\left(e^{x}\right) \bmod \left(\sqrt{\cos x}\right)\right) - x\right)\right) \cdot 0.3333333333333333}} \]
  7. Taylor expanded in x around inf 60.3%

    \[\leadsto e^{\color{blue}{\left(-3 \cdot x\right)} \cdot 0.3333333333333333} \]
  8. Step-by-step derivation
    1. *-commutative60.3%

      \[\leadsto e^{\color{blue}{\left(x \cdot -3\right)} \cdot 0.3333333333333333} \]
  9. Simplified60.3%

    \[\leadsto e^{\color{blue}{\left(x \cdot -3\right)} \cdot 0.3333333333333333} \]
  10. Taylor expanded in x around 0 60.3%

    \[\leadsto e^{\color{blue}{-1 \cdot x}} \]
  11. Step-by-step derivation
    1. neg-mul-160.3%

      \[\leadsto e^{\color{blue}{-x}} \]
  12. Simplified60.3%

    \[\leadsto e^{\color{blue}{-x}} \]
  13. Add Preprocessing

Alternative 4: 41.5% accurate, 5.0× speedup?

\[\begin{array}{l} \\ e^{x} \end{array} \]
(FPCore (x) :precision binary64 (exp x))
double code(double x) {
	return exp(x);
}
real(8) function code(x)
    real(8), intent (in) :: x
    code = exp(x)
end function
public static double code(double x) {
	return Math.exp(x);
}
def code(x):
	return math.exp(x)
function code(x)
	return exp(x)
end
function tmp = code(x)
	tmp = exp(x);
end
code[x_] := N[Exp[x], $MachinePrecision]
\begin{array}{l}

\\
e^{x}
\end{array}
Derivation
  1. Initial program 7.8%

    \[\left(\left(e^{x}\right) \bmod \left(\sqrt{\cos x}\right)\right) \cdot e^{-x} \]
  2. Step-by-step derivation
    1. /-rgt-identity7.8%

      \[\leadsto \color{blue}{\frac{\left(\left(e^{x}\right) \bmod \left(\sqrt{\cos x}\right)\right)}{1}} \cdot e^{-x} \]
    2. associate-/r/7.8%

      \[\leadsto \color{blue}{\frac{\left(\left(e^{x}\right) \bmod \left(\sqrt{\cos x}\right)\right)}{\frac{1}{e^{-x}}}} \]
    3. exp-neg7.8%

      \[\leadsto \frac{\left(\left(e^{x}\right) \bmod \left(\sqrt{\cos x}\right)\right)}{\color{blue}{e^{-\left(-x\right)}}} \]
    4. remove-double-neg7.8%

      \[\leadsto \frac{\left(\left(e^{x}\right) \bmod \left(\sqrt{\cos x}\right)\right)}{e^{\color{blue}{x}}} \]
  3. Simplified7.8%

    \[\leadsto \color{blue}{\frac{\left(\left(e^{x}\right) \bmod \left(\sqrt{\cos x}\right)\right)}{e^{x}}} \]
  4. Add Preprocessing
  5. Step-by-step derivation
    1. add-cbrt-cube7.8%

      \[\leadsto \color{blue}{\sqrt[3]{\left(\frac{\left(\left(e^{x}\right) \bmod \left(\sqrt{\cos x}\right)\right)}{e^{x}} \cdot \frac{\left(\left(e^{x}\right) \bmod \left(\sqrt{\cos x}\right)\right)}{e^{x}}\right) \cdot \frac{\left(\left(e^{x}\right) \bmod \left(\sqrt{\cos x}\right)\right)}{e^{x}}}} \]
    2. pow1/37.8%

      \[\leadsto \color{blue}{{\left(\left(\frac{\left(\left(e^{x}\right) \bmod \left(\sqrt{\cos x}\right)\right)}{e^{x}} \cdot \frac{\left(\left(e^{x}\right) \bmod \left(\sqrt{\cos x}\right)\right)}{e^{x}}\right) \cdot \frac{\left(\left(e^{x}\right) \bmod \left(\sqrt{\cos x}\right)\right)}{e^{x}}\right)}^{0.3333333333333333}} \]
    3. pow-to-exp7.8%

      \[\leadsto \color{blue}{e^{\log \left(\left(\frac{\left(\left(e^{x}\right) \bmod \left(\sqrt{\cos x}\right)\right)}{e^{x}} \cdot \frac{\left(\left(e^{x}\right) \bmod \left(\sqrt{\cos x}\right)\right)}{e^{x}}\right) \cdot \frac{\left(\left(e^{x}\right) \bmod \left(\sqrt{\cos x}\right)\right)}{e^{x}}\right) \cdot 0.3333333333333333}} \]
    4. pow37.8%

      \[\leadsto e^{\log \color{blue}{\left({\left(\frac{\left(\left(e^{x}\right) \bmod \left(\sqrt{\cos x}\right)\right)}{e^{x}}\right)}^{3}\right)} \cdot 0.3333333333333333} \]
    5. log-pow7.8%

      \[\leadsto e^{\color{blue}{\left(3 \cdot \log \left(\frac{\left(\left(e^{x}\right) \bmod \left(\sqrt{\cos x}\right)\right)}{e^{x}}\right)\right)} \cdot 0.3333333333333333} \]
    6. log-div7.8%

      \[\leadsto e^{\left(3 \cdot \color{blue}{\left(\log \left(\left(e^{x}\right) \bmod \left(\sqrt{\cos x}\right)\right) - \log \left(e^{x}\right)\right)}\right) \cdot 0.3333333333333333} \]
    7. add-log-exp7.8%

      \[\leadsto e^{\left(3 \cdot \left(\log \left(\left(e^{x}\right) \bmod \left(\sqrt{\cos x}\right)\right) - \color{blue}{x}\right)\right) \cdot 0.3333333333333333} \]
  6. Applied egg-rr7.8%

    \[\leadsto \color{blue}{e^{\left(3 \cdot \left(\log \left(\left(e^{x}\right) \bmod \left(\sqrt{\cos x}\right)\right) - x\right)\right) \cdot 0.3333333333333333}} \]
  7. Taylor expanded in x around inf 60.3%

    \[\leadsto e^{\color{blue}{\left(-3 \cdot x\right)} \cdot 0.3333333333333333} \]
  8. Step-by-step derivation
    1. *-commutative60.3%

      \[\leadsto e^{\color{blue}{\left(x \cdot -3\right)} \cdot 0.3333333333333333} \]
  9. Simplified60.3%

    \[\leadsto e^{\color{blue}{\left(x \cdot -3\right)} \cdot 0.3333333333333333} \]
  10. Step-by-step derivation
    1. add-sqr-sqrt38.6%

      \[\leadsto e^{\color{blue}{\sqrt{\left(x \cdot -3\right) \cdot 0.3333333333333333} \cdot \sqrt{\left(x \cdot -3\right) \cdot 0.3333333333333333}}} \]
    2. sqrt-unprod41.1%

      \[\leadsto e^{\color{blue}{\sqrt{\left(\left(x \cdot -3\right) \cdot 0.3333333333333333\right) \cdot \left(\left(x \cdot -3\right) \cdot 0.3333333333333333\right)}}} \]
    3. associate-*l*41.1%

      \[\leadsto e^{\sqrt{\color{blue}{\left(x \cdot \left(-3 \cdot 0.3333333333333333\right)\right)} \cdot \left(\left(x \cdot -3\right) \cdot 0.3333333333333333\right)}} \]
    4. metadata-eval41.1%

      \[\leadsto e^{\sqrt{\left(x \cdot \color{blue}{-1}\right) \cdot \left(\left(x \cdot -3\right) \cdot 0.3333333333333333\right)}} \]
    5. associate-*l*41.1%

      \[\leadsto e^{\sqrt{\left(x \cdot -1\right) \cdot \color{blue}{\left(x \cdot \left(-3 \cdot 0.3333333333333333\right)\right)}}} \]
    6. metadata-eval41.1%

      \[\leadsto e^{\sqrt{\left(x \cdot -1\right) \cdot \left(x \cdot \color{blue}{-1}\right)}} \]
    7. swap-sqr41.1%

      \[\leadsto e^{\sqrt{\color{blue}{\left(x \cdot x\right) \cdot \left(-1 \cdot -1\right)}}} \]
    8. unpow241.1%

      \[\leadsto e^{\sqrt{\color{blue}{{x}^{2}} \cdot \left(-1 \cdot -1\right)}} \]
    9. metadata-eval41.1%

      \[\leadsto e^{\sqrt{{x}^{2} \cdot \color{blue}{1}}} \]
    10. *-commutative41.1%

      \[\leadsto e^{\sqrt{\color{blue}{1 \cdot {x}^{2}}}} \]
    11. *-un-lft-identity41.1%

      \[\leadsto e^{\sqrt{\color{blue}{{x}^{2}}}} \]
    12. sqrt-pow141.1%

      \[\leadsto e^{\color{blue}{{x}^{\left(\frac{2}{2}\right)}}} \]
    13. metadata-eval41.1%

      \[\leadsto e^{{x}^{\color{blue}{1}}} \]
    14. pow141.1%

      \[\leadsto e^{\color{blue}{x}} \]
    15. add-log-exp41.1%

      \[\leadsto e^{\color{blue}{\log \left(e^{x}\right)}} \]
    16. *-un-lft-identity41.1%

      \[\leadsto e^{\log \color{blue}{\left(1 \cdot e^{x}\right)}} \]
    17. log-prod41.1%

      \[\leadsto e^{\color{blue}{\log 1 + \log \left(e^{x}\right)}} \]
    18. metadata-eval41.1%

      \[\leadsto e^{\color{blue}{0} + \log \left(e^{x}\right)} \]
    19. add-log-exp41.1%

      \[\leadsto e^{0 + \color{blue}{x}} \]
  11. Applied egg-rr41.1%

    \[\leadsto e^{\color{blue}{0 + x}} \]
  12. Step-by-step derivation
    1. +-lft-identity41.1%

      \[\leadsto e^{\color{blue}{x}} \]
  13. Simplified41.1%

    \[\leadsto e^{\color{blue}{x}} \]
  14. Add Preprocessing

Reproduce

?
herbie shell --seed 2024102 
(FPCore (x)
  :name "expfmod (used to be hard to sample)"
  :precision binary64
  (* (fmod (exp x) (sqrt (cos x))) (exp (- x))))