expfmod (used to be hard to sample)

Percentage Accurate: 7.2% → 65.6%
Time: 12.8s
Alternatives: 13
Speedup: 4.1×

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 13 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: 65.6% accurate, 1.2× speedup?

\[\begin{array}{l} \\ \begin{array}{l} t_0 := e^{-x}\\ \mathbf{if}\;x \leq -5 \cdot 10^{-72}:\\ \;\;\;\;\left(\left(\left(x \cdot \left(x \cdot x\right)\right) \cdot \left(0.16666666666666666 + \left(\frac{\frac{\frac{1}{x \cdot x}}{\frac{1}{x} - \mathsf{fma}\left(x, 0.5, 1\right)}}{x \cdot x} + \frac{\frac{\mathsf{fma}\left(x, 0.5, 1\right) \cdot \mathsf{fma}\left(x, 0.5, 1\right)}{\mathsf{fma}\left(x, 0.5, 1\right) + \frac{-1}{x}}}{x \cdot x}\right)\right)\right) \bmod 1\right) \cdot t\_0\\ \mathbf{elif}\;x \leq -1.55 \cdot 10^{-162}:\\ \;\;\;\;t\_0 \cdot \left(\left(\mathsf{fma}\left(\frac{x \cdot x}{x}, \frac{x}{\frac{x}{1 + \mathsf{fma}\left(x, 0.5, \frac{1}{x}\right)}}, x \cdot \left(0.16666666666666666 \cdot \left(x \cdot x\right)\right)\right)\right) \bmod 1\right)\\ \mathbf{elif}\;x \leq 0.6:\\ \;\;\;\;t\_0 \cdot \left(\left(\mathsf{fma}\left(x, x \cdot 0.5, x\right)\right) \bmod 1\right)\\ \mathbf{else}:\\ \;\;\;\;t\_0 \cdot \left(\left(x + 1\right) \bmod \left(\sqrt{\cos x}\right)\right)\\ \end{array} \end{array} \]
(FPCore (x)
 :precision binary64
 (let* ((t_0 (exp (- x))))
   (if (<= x -5e-72)
     (*
      (fmod
       (*
        (* x (* x x))
        (+
         0.16666666666666666
         (+
          (/ (/ (/ 1.0 (* x x)) (- (/ 1.0 x) (fma x 0.5 1.0))) (* x x))
          (/
           (/
            (* (fma x 0.5 1.0) (fma x 0.5 1.0))
            (+ (fma x 0.5 1.0) (/ -1.0 x)))
           (* x x)))))
       1.0)
      t_0)
     (if (<= x -1.55e-162)
       (*
        t_0
        (fmod
         (fma
          (/ (* x x) x)
          (/ x (/ x (+ 1.0 (fma x 0.5 (/ 1.0 x)))))
          (* x (* 0.16666666666666666 (* x x))))
         1.0))
       (if (<= x 0.6)
         (* t_0 (fmod (fma x (* x 0.5) x) 1.0))
         (* t_0 (fmod (+ x 1.0) (sqrt (cos x)))))))))
double code(double x) {
	double t_0 = exp(-x);
	double tmp;
	if (x <= -5e-72) {
		tmp = fmod(((x * (x * x)) * (0.16666666666666666 + ((((1.0 / (x * x)) / ((1.0 / x) - fma(x, 0.5, 1.0))) / (x * x)) + (((fma(x, 0.5, 1.0) * fma(x, 0.5, 1.0)) / (fma(x, 0.5, 1.0) + (-1.0 / x))) / (x * x))))), 1.0) * t_0;
	} else if (x <= -1.55e-162) {
		tmp = t_0 * fmod(fma(((x * x) / x), (x / (x / (1.0 + fma(x, 0.5, (1.0 / x))))), (x * (0.16666666666666666 * (x * x)))), 1.0);
	} else if (x <= 0.6) {
		tmp = t_0 * fmod(fma(x, (x * 0.5), x), 1.0);
	} else {
		tmp = t_0 * fmod((x + 1.0), sqrt(cos(x)));
	}
	return tmp;
}
function code(x)
	t_0 = exp(Float64(-x))
	tmp = 0.0
	if (x <= -5e-72)
		tmp = Float64(rem(Float64(Float64(x * Float64(x * x)) * Float64(0.16666666666666666 + Float64(Float64(Float64(Float64(1.0 / Float64(x * x)) / Float64(Float64(1.0 / x) - fma(x, 0.5, 1.0))) / Float64(x * x)) + Float64(Float64(Float64(fma(x, 0.5, 1.0) * fma(x, 0.5, 1.0)) / Float64(fma(x, 0.5, 1.0) + Float64(-1.0 / x))) / Float64(x * x))))), 1.0) * t_0);
	elseif (x <= -1.55e-162)
		tmp = Float64(t_0 * rem(fma(Float64(Float64(x * x) / x), Float64(x / Float64(x / Float64(1.0 + fma(x, 0.5, Float64(1.0 / x))))), Float64(x * Float64(0.16666666666666666 * Float64(x * x)))), 1.0));
	elseif (x <= 0.6)
		tmp = Float64(t_0 * rem(fma(x, Float64(x * 0.5), x), 1.0));
	else
		tmp = Float64(t_0 * rem(Float64(x + 1.0), sqrt(cos(x))));
	end
	return tmp
end
code[x_] := Block[{t$95$0 = N[Exp[(-x)], $MachinePrecision]}, If[LessEqual[x, -5e-72], N[(N[With[{TMP1 = N[(N[(x * N[(x * x), $MachinePrecision]), $MachinePrecision] * N[(0.16666666666666666 + N[(N[(N[(N[(1.0 / N[(x * x), $MachinePrecision]), $MachinePrecision] / N[(N[(1.0 / x), $MachinePrecision] - N[(x * 0.5 + 1.0), $MachinePrecision]), $MachinePrecision]), $MachinePrecision] / N[(x * x), $MachinePrecision]), $MachinePrecision] + N[(N[(N[(N[(x * 0.5 + 1.0), $MachinePrecision] * N[(x * 0.5 + 1.0), $MachinePrecision]), $MachinePrecision] / N[(N[(x * 0.5 + 1.0), $MachinePrecision] + N[(-1.0 / x), $MachinePrecision]), $MachinePrecision]), $MachinePrecision] / N[(x * x), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision], TMP2 = 1.0}, Mod[Abs[TMP1], Abs[TMP2]] * Sign[TMP1]], $MachinePrecision] * t$95$0), $MachinePrecision], If[LessEqual[x, -1.55e-162], N[(t$95$0 * N[With[{TMP1 = N[(N[(N[(x * x), $MachinePrecision] / x), $MachinePrecision] * N[(x / N[(x / N[(1.0 + N[(x * 0.5 + N[(1.0 / x), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision] + N[(x * N[(0.16666666666666666 * N[(x * x), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision], TMP2 = 1.0}, Mod[Abs[TMP1], Abs[TMP2]] * Sign[TMP1]], $MachinePrecision]), $MachinePrecision], If[LessEqual[x, 0.6], N[(t$95$0 * N[With[{TMP1 = N[(x * N[(x * 0.5), $MachinePrecision] + x), $MachinePrecision], TMP2 = 1.0}, Mod[Abs[TMP1], Abs[TMP2]] * Sign[TMP1]], $MachinePrecision]), $MachinePrecision], N[(t$95$0 * N[With[{TMP1 = N[(x + 1.0), $MachinePrecision], TMP2 = N[Sqrt[N[Cos[x], $MachinePrecision]], $MachinePrecision]}, Mod[Abs[TMP1], Abs[TMP2]] * Sign[TMP1]], $MachinePrecision]), $MachinePrecision]]]]]
\begin{array}{l}

\\
\begin{array}{l}
t_0 := e^{-x}\\
\mathbf{if}\;x \leq -5 \cdot 10^{-72}:\\
\;\;\;\;\left(\left(\left(x \cdot \left(x \cdot x\right)\right) \cdot \left(0.16666666666666666 + \left(\frac{\frac{\frac{1}{x \cdot x}}{\frac{1}{x} - \mathsf{fma}\left(x, 0.5, 1\right)}}{x \cdot x} + \frac{\frac{\mathsf{fma}\left(x, 0.5, 1\right) \cdot \mathsf{fma}\left(x, 0.5, 1\right)}{\mathsf{fma}\left(x, 0.5, 1\right) + \frac{-1}{x}}}{x \cdot x}\right)\right)\right) \bmod 1\right) \cdot t\_0\\

\mathbf{elif}\;x \leq -1.55 \cdot 10^{-162}:\\
\;\;\;\;t\_0 \cdot \left(\left(\mathsf{fma}\left(\frac{x \cdot x}{x}, \frac{x}{\frac{x}{1 + \mathsf{fma}\left(x, 0.5, \frac{1}{x}\right)}}, x \cdot \left(0.16666666666666666 \cdot \left(x \cdot x\right)\right)\right)\right) \bmod 1\right)\\

\mathbf{elif}\;x \leq 0.6:\\
\;\;\;\;t\_0 \cdot \left(\left(\mathsf{fma}\left(x, x \cdot 0.5, x\right)\right) \bmod 1\right)\\

\mathbf{else}:\\
\;\;\;\;t\_0 \cdot \left(\left(x + 1\right) \bmod \left(\sqrt{\cos x}\right)\right)\\


\end{array}
\end{array}
Derivation
  1. Split input into 4 regimes
  2. if x < -4.9999999999999996e-72

    1. Initial program 20.3%

      \[\left(\left(e^{x}\right) \bmod \left(\sqrt{\cos x}\right)\right) \cdot e^{-x} \]
    2. Add Preprocessing
    3. Taylor expanded in x around 0

      \[\leadsto \left(\left(e^{x}\right) \bmod \color{blue}{1}\right) \cdot e^{\mathsf{neg}\left(x\right)} \]
    4. Step-by-step derivation
      1. Applied rewrites20.3%

        \[\leadsto \left(\left(e^{x}\right) \bmod \color{blue}{1}\right) \cdot e^{-x} \]
      2. Taylor expanded in x around 0

        \[\leadsto \left(\color{blue}{\left(1 + x \cdot \left(1 + x \cdot \left(\frac{1}{2} + \frac{1}{6} \cdot x\right)\right)\right)} \bmod 1\right) \cdot e^{\mathsf{neg}\left(x\right)} \]
      3. Step-by-step derivation
        1. +-commutativeN/A

          \[\leadsto \left(\color{blue}{\left(x \cdot \left(1 + x \cdot \left(\frac{1}{2} + \frac{1}{6} \cdot x\right)\right) + 1\right)} \bmod 1\right) \cdot e^{\mathsf{neg}\left(x\right)} \]
        2. lower-fma.f64N/A

          \[\leadsto \left(\color{blue}{\left(\mathsf{fma}\left(x, 1 + x \cdot \left(\frac{1}{2} + \frac{1}{6} \cdot x\right), 1\right)\right)} \bmod 1\right) \cdot e^{\mathsf{neg}\left(x\right)} \]
        3. +-commutativeN/A

          \[\leadsto \left(\left(\mathsf{fma}\left(x, \color{blue}{x \cdot \left(\frac{1}{2} + \frac{1}{6} \cdot x\right) + 1}, 1\right)\right) \bmod 1\right) \cdot e^{\mathsf{neg}\left(x\right)} \]
        4. lower-fma.f64N/A

          \[\leadsto \left(\left(\mathsf{fma}\left(x, \color{blue}{\mathsf{fma}\left(x, \frac{1}{2} + \frac{1}{6} \cdot x, 1\right)}, 1\right)\right) \bmod 1\right) \cdot e^{\mathsf{neg}\left(x\right)} \]
        5. +-commutativeN/A

          \[\leadsto \left(\left(\mathsf{fma}\left(x, \mathsf{fma}\left(x, \color{blue}{\frac{1}{6} \cdot x + \frac{1}{2}}, 1\right), 1\right)\right) \bmod 1\right) \cdot e^{\mathsf{neg}\left(x\right)} \]
        6. *-commutativeN/A

          \[\leadsto \left(\left(\mathsf{fma}\left(x, \mathsf{fma}\left(x, \color{blue}{x \cdot \frac{1}{6}} + \frac{1}{2}, 1\right), 1\right)\right) \bmod 1\right) \cdot e^{\mathsf{neg}\left(x\right)} \]
        7. lower-fma.f6412.9

          \[\leadsto \left(\left(\mathsf{fma}\left(x, \mathsf{fma}\left(x, \color{blue}{\mathsf{fma}\left(x, 0.16666666666666666, 0.5\right)}, 1\right), 1\right)\right) \bmod 1\right) \cdot e^{-x} \]
      4. Applied rewrites12.9%

        \[\leadsto \left(\color{blue}{\left(\mathsf{fma}\left(x, \mathsf{fma}\left(x, \mathsf{fma}\left(x, 0.16666666666666666, 0.5\right), 1\right), 1\right)\right)} \bmod 1\right) \cdot e^{-x} \]
      5. Taylor expanded in x around -inf

        \[\leadsto \left(\left(-1 \cdot \color{blue}{\left({x}^{3} \cdot \left(-1 \cdot \frac{\frac{1}{2} + \left(\frac{1}{x} + \frac{1}{{x}^{2}}\right)}{x} - \frac{1}{6}\right)\right)}\right) \bmod 1\right) \cdot e^{\mathsf{neg}\left(x\right)} \]
      6. Applied rewrites27.5%

        \[\leadsto \left(\left(\left(x \cdot \left(x \cdot x\right)\right) \cdot \color{blue}{\left(0.16666666666666666 + \frac{\frac{\frac{1}{x} + \mathsf{fma}\left(x, 0.5, 1\right)}{x}}{x}\right)}\right) \bmod 1\right) \cdot e^{-x} \]
      7. Step-by-step derivation
        1. Applied rewrites57.0%

          \[\leadsto \left(\left(\left(x \cdot \left(x \cdot x\right)\right) \cdot \left(0.16666666666666666 + \left(\frac{\frac{\frac{1}{x \cdot x}}{\frac{1}{x} - \mathsf{fma}\left(x, 0.5, 1\right)}}{x \cdot x} - \frac{\frac{\mathsf{fma}\left(x, 0.5, 1\right) \cdot \mathsf{fma}\left(x, 0.5, 1\right)}{\frac{1}{x} - \mathsf{fma}\left(x, 0.5, 1\right)}}{\color{blue}{x \cdot x}}\right)\right)\right) \bmod 1\right) \cdot e^{-x} \]

        if -4.9999999999999996e-72 < x < -1.5499999999999999e-162

        1. Initial program 3.1%

          \[\left(\left(e^{x}\right) \bmod \left(\sqrt{\cos x}\right)\right) \cdot e^{-x} \]
        2. Add Preprocessing
        3. Taylor expanded in x around 0

          \[\leadsto \left(\left(e^{x}\right) \bmod \color{blue}{1}\right) \cdot e^{\mathsf{neg}\left(x\right)} \]
        4. Step-by-step derivation
          1. Applied rewrites3.1%

            \[\leadsto \left(\left(e^{x}\right) \bmod \color{blue}{1}\right) \cdot e^{-x} \]
          2. Taylor expanded in x around 0

            \[\leadsto \left(\color{blue}{\left(1 + x \cdot \left(1 + x \cdot \left(\frac{1}{2} + \frac{1}{6} \cdot x\right)\right)\right)} \bmod 1\right) \cdot e^{\mathsf{neg}\left(x\right)} \]
          3. Step-by-step derivation
            1. +-commutativeN/A

              \[\leadsto \left(\color{blue}{\left(x \cdot \left(1 + x \cdot \left(\frac{1}{2} + \frac{1}{6} \cdot x\right)\right) + 1\right)} \bmod 1\right) \cdot e^{\mathsf{neg}\left(x\right)} \]
            2. lower-fma.f64N/A

              \[\leadsto \left(\color{blue}{\left(\mathsf{fma}\left(x, 1 + x \cdot \left(\frac{1}{2} + \frac{1}{6} \cdot x\right), 1\right)\right)} \bmod 1\right) \cdot e^{\mathsf{neg}\left(x\right)} \]
            3. +-commutativeN/A

              \[\leadsto \left(\left(\mathsf{fma}\left(x, \color{blue}{x \cdot \left(\frac{1}{2} + \frac{1}{6} \cdot x\right) + 1}, 1\right)\right) \bmod 1\right) \cdot e^{\mathsf{neg}\left(x\right)} \]
            4. lower-fma.f64N/A

              \[\leadsto \left(\left(\mathsf{fma}\left(x, \color{blue}{\mathsf{fma}\left(x, \frac{1}{2} + \frac{1}{6} \cdot x, 1\right)}, 1\right)\right) \bmod 1\right) \cdot e^{\mathsf{neg}\left(x\right)} \]
            5. +-commutativeN/A

              \[\leadsto \left(\left(\mathsf{fma}\left(x, \mathsf{fma}\left(x, \color{blue}{\frac{1}{6} \cdot x + \frac{1}{2}}, 1\right), 1\right)\right) \bmod 1\right) \cdot e^{\mathsf{neg}\left(x\right)} \]
            6. *-commutativeN/A

              \[\leadsto \left(\left(\mathsf{fma}\left(x, \mathsf{fma}\left(x, \color{blue}{x \cdot \frac{1}{6}} + \frac{1}{2}, 1\right), 1\right)\right) \bmod 1\right) \cdot e^{\mathsf{neg}\left(x\right)} \]
            7. lower-fma.f643.1

              \[\leadsto \left(\left(\mathsf{fma}\left(x, \mathsf{fma}\left(x, \color{blue}{\mathsf{fma}\left(x, 0.16666666666666666, 0.5\right)}, 1\right), 1\right)\right) \bmod 1\right) \cdot e^{-x} \]
          4. Applied rewrites3.1%

            \[\leadsto \left(\color{blue}{\left(\mathsf{fma}\left(x, \mathsf{fma}\left(x, \mathsf{fma}\left(x, 0.16666666666666666, 0.5\right), 1\right), 1\right)\right)} \bmod 1\right) \cdot e^{-x} \]
          5. Taylor expanded in x around -inf

            \[\leadsto \left(\left(-1 \cdot \color{blue}{\left({x}^{3} \cdot \left(-1 \cdot \frac{\frac{1}{2} + \left(\frac{1}{x} + \frac{1}{{x}^{2}}\right)}{x} - \frac{1}{6}\right)\right)}\right) \bmod 1\right) \cdot e^{\mathsf{neg}\left(x\right)} \]
          6. Applied rewrites7.8%

            \[\leadsto \left(\left(\left(x \cdot \left(x \cdot x\right)\right) \cdot \color{blue}{\left(0.16666666666666666 + \frac{\frac{\frac{1}{x} + \mathsf{fma}\left(x, 0.5, 1\right)}{x}}{x}\right)}\right) \bmod 1\right) \cdot e^{-x} \]
          7. Step-by-step derivation
            1. Applied rewrites31.5%

              \[\leadsto \left(\left(\mathsf{fma}\left(\frac{x \cdot x}{x}, \frac{x}{\color{blue}{\frac{x}{1 + \mathsf{fma}\left(x, 0.5, \frac{1}{x}\right)}}}, x \cdot \left(\left(x \cdot x\right) \cdot 0.16666666666666666\right)\right)\right) \bmod 1\right) \cdot e^{-x} \]

            if -1.5499999999999999e-162 < x < 0.599999999999999978

            1. Initial program 5.2%

              \[\left(\left(e^{x}\right) \bmod \left(\sqrt{\cos x}\right)\right) \cdot e^{-x} \]
            2. Add Preprocessing
            3. Taylor expanded in x around 0

              \[\leadsto \left(\color{blue}{\left(1 + x \cdot \left(1 + \frac{1}{2} \cdot x\right)\right)} \bmod \left(\sqrt{\cos x}\right)\right) \cdot e^{\mathsf{neg}\left(x\right)} \]
            4. Step-by-step derivation
              1. +-commutativeN/A

                \[\leadsto \left(\color{blue}{\left(x \cdot \left(1 + \frac{1}{2} \cdot x\right) + 1\right)} \bmod \left(\sqrt{\cos x}\right)\right) \cdot e^{\mathsf{neg}\left(x\right)} \]
              2. lower-fma.f64N/A

                \[\leadsto \left(\color{blue}{\left(\mathsf{fma}\left(x, 1 + \frac{1}{2} \cdot x, 1\right)\right)} \bmod \left(\sqrt{\cos x}\right)\right) \cdot e^{\mathsf{neg}\left(x\right)} \]
              3. +-commutativeN/A

                \[\leadsto \left(\left(\mathsf{fma}\left(x, \color{blue}{\frac{1}{2} \cdot x + 1}, 1\right)\right) \bmod \left(\sqrt{\cos x}\right)\right) \cdot e^{\mathsf{neg}\left(x\right)} \]
              4. *-commutativeN/A

                \[\leadsto \left(\left(\mathsf{fma}\left(x, \color{blue}{x \cdot \frac{1}{2}} + 1, 1\right)\right) \bmod \left(\sqrt{\cos x}\right)\right) \cdot e^{\mathsf{neg}\left(x\right)} \]
              5. lower-fma.f645.2

                \[\leadsto \left(\left(\mathsf{fma}\left(x, \color{blue}{\mathsf{fma}\left(x, 0.5, 1\right)}, 1\right)\right) \bmod \left(\sqrt{\cos x}\right)\right) \cdot e^{-x} \]
            5. Applied rewrites5.2%

              \[\leadsto \left(\color{blue}{\left(\mathsf{fma}\left(x, \mathsf{fma}\left(x, 0.5, 1\right), 1\right)\right)} \bmod \left(\sqrt{\cos x}\right)\right) \cdot e^{-x} \]
            6. Taylor expanded in x around inf

              \[\leadsto \left(\left({x}^{2} \cdot \color{blue}{\left(\frac{1}{2} + \frac{1}{x}\right)}\right) \bmod \left(\sqrt{\cos x}\right)\right) \cdot e^{\mathsf{neg}\left(x\right)} \]
            7. Step-by-step derivation
              1. Applied rewrites62.9%

                \[\leadsto \left(\left(\mathsf{fma}\left(x, \color{blue}{x \cdot 0.5}, x\right)\right) \bmod \left(\sqrt{\cos x}\right)\right) \cdot e^{-x} \]
              2. Taylor expanded in x around 0

                \[\leadsto \left(\left(\mathsf{fma}\left(x, x \cdot \frac{1}{2}, x\right)\right) \bmod \color{blue}{1}\right) \cdot e^{\mathsf{neg}\left(x\right)} \]
              3. Step-by-step derivation
                1. Applied rewrites62.9%

                  \[\leadsto \left(\left(\mathsf{fma}\left(x, x \cdot 0.5, x\right)\right) \bmod \color{blue}{1}\right) \cdot e^{-x} \]

                if 0.599999999999999978 < x

                1. Initial program 2.0%

                  \[\left(\left(e^{x}\right) \bmod \left(\sqrt{\cos x}\right)\right) \cdot e^{-x} \]
                2. Add Preprocessing
                3. Taylor expanded in x around 0

                  \[\leadsto \left(\color{blue}{\left(1 + x\right)} \bmod \left(\sqrt{\cos x}\right)\right) \cdot e^{\mathsf{neg}\left(x\right)} \]
                4. Step-by-step derivation
                  1. +-commutativeN/A

                    \[\leadsto \left(\color{blue}{\left(x + 1\right)} \bmod \left(\sqrt{\cos x}\right)\right) \cdot e^{\mathsf{neg}\left(x\right)} \]
                  2. lower-+.f6496.8

                    \[\leadsto \left(\color{blue}{\left(x + 1\right)} \bmod \left(\sqrt{\cos x}\right)\right) \cdot e^{-x} \]
                5. Applied rewrites96.8%

                  \[\leadsto \left(\color{blue}{\left(x + 1\right)} \bmod \left(\sqrt{\cos x}\right)\right) \cdot e^{-x} \]
              4. Recombined 4 regimes into one program.
              5. Final simplification65.7%

                \[\leadsto \begin{array}{l} \mathbf{if}\;x \leq -5 \cdot 10^{-72}:\\ \;\;\;\;\left(\left(\left(x \cdot \left(x \cdot x\right)\right) \cdot \left(0.16666666666666666 + \left(\frac{\frac{\frac{1}{x \cdot x}}{\frac{1}{x} - \mathsf{fma}\left(x, 0.5, 1\right)}}{x \cdot x} + \frac{\frac{\mathsf{fma}\left(x, 0.5, 1\right) \cdot \mathsf{fma}\left(x, 0.5, 1\right)}{\mathsf{fma}\left(x, 0.5, 1\right) + \frac{-1}{x}}}{x \cdot x}\right)\right)\right) \bmod 1\right) \cdot e^{-x}\\ \mathbf{elif}\;x \leq -1.55 \cdot 10^{-162}:\\ \;\;\;\;e^{-x} \cdot \left(\left(\mathsf{fma}\left(\frac{x \cdot x}{x}, \frac{x}{\frac{x}{1 + \mathsf{fma}\left(x, 0.5, \frac{1}{x}\right)}}, x \cdot \left(0.16666666666666666 \cdot \left(x \cdot x\right)\right)\right)\right) \bmod 1\right)\\ \mathbf{elif}\;x \leq 0.6:\\ \;\;\;\;e^{-x} \cdot \left(\left(\mathsf{fma}\left(x, x \cdot 0.5, x\right)\right) \bmod 1\right)\\ \mathbf{else}:\\ \;\;\;\;e^{-x} \cdot \left(\left(x + 1\right) \bmod \left(\sqrt{\cos x}\right)\right)\\ \end{array} \]
              6. Add Preprocessing

              Alternative 2: 60.4% accurate, 0.7× speedup?

              \[\begin{array}{l} \\ \begin{array}{l} t_0 := e^{-x}\\ \mathbf{if}\;t\_0 \cdot \left(\left(e^{x}\right) \bmod \left(\sqrt{\cos x}\right)\right) \leq 0.001:\\ \;\;\;\;t\_0 \cdot \left(\left(\mathsf{fma}\left(x, x \cdot 0.5, x\right)\right) \bmod 1\right)\\ \mathbf{else}:\\ \;\;\;\;\frac{\left(\left(x + 1\right) \bmod 1\right)}{e^{x}}\\ \end{array} \end{array} \]
              (FPCore (x)
               :precision binary64
               (let* ((t_0 (exp (- x))))
                 (if (<= (* t_0 (fmod (exp x) (sqrt (cos x)))) 0.001)
                   (* t_0 (fmod (fma x (* x 0.5) x) 1.0))
                   (/ (fmod (+ x 1.0) 1.0) (exp x)))))
              double code(double x) {
              	double t_0 = exp(-x);
              	double tmp;
              	if ((t_0 * fmod(exp(x), sqrt(cos(x)))) <= 0.001) {
              		tmp = t_0 * fmod(fma(x, (x * 0.5), x), 1.0);
              	} else {
              		tmp = fmod((x + 1.0), 1.0) / exp(x);
              	}
              	return tmp;
              }
              
              function code(x)
              	t_0 = exp(Float64(-x))
              	tmp = 0.0
              	if (Float64(t_0 * rem(exp(x), sqrt(cos(x)))) <= 0.001)
              		tmp = Float64(t_0 * rem(fma(x, Float64(x * 0.5), x), 1.0));
              	else
              		tmp = Float64(rem(Float64(x + 1.0), 1.0) / exp(x));
              	end
              	return tmp
              end
              
              code[x_] := Block[{t$95$0 = N[Exp[(-x)], $MachinePrecision]}, If[LessEqual[N[(t$95$0 * N[With[{TMP1 = N[Exp[x], $MachinePrecision], TMP2 = N[Sqrt[N[Cos[x], $MachinePrecision]], $MachinePrecision]}, Mod[Abs[TMP1], Abs[TMP2]] * Sign[TMP1]], $MachinePrecision]), $MachinePrecision], 0.001], N[(t$95$0 * N[With[{TMP1 = N[(x * N[(x * 0.5), $MachinePrecision] + x), $MachinePrecision], TMP2 = 1.0}, Mod[Abs[TMP1], Abs[TMP2]] * Sign[TMP1]], $MachinePrecision]), $MachinePrecision], N[(N[With[{TMP1 = N[(x + 1.0), $MachinePrecision], TMP2 = 1.0}, Mod[Abs[TMP1], Abs[TMP2]] * Sign[TMP1]], $MachinePrecision] / N[Exp[x], $MachinePrecision]), $MachinePrecision]]]
              
              \begin{array}{l}
              
              \\
              \begin{array}{l}
              t_0 := e^{-x}\\
              \mathbf{if}\;t\_0 \cdot \left(\left(e^{x}\right) \bmod \left(\sqrt{\cos x}\right)\right) \leq 0.001:\\
              \;\;\;\;t\_0 \cdot \left(\left(\mathsf{fma}\left(x, x \cdot 0.5, x\right)\right) \bmod 1\right)\\
              
              \mathbf{else}:\\
              \;\;\;\;\frac{\left(\left(x + 1\right) \bmod 1\right)}{e^{x}}\\
              
              
              \end{array}
              \end{array}
              
              Derivation
              1. Split input into 2 regimes
              2. if (*.f64 (fmod.f64 (exp.f64 x) (sqrt.f64 (cos.f64 x))) (exp.f64 (neg.f64 x))) < 1e-3

                1. Initial program 5.6%

                  \[\left(\left(e^{x}\right) \bmod \left(\sqrt{\cos x}\right)\right) \cdot e^{-x} \]
                2. Add Preprocessing
                3. Taylor expanded in x around 0

                  \[\leadsto \left(\color{blue}{\left(1 + x \cdot \left(1 + \frac{1}{2} \cdot x\right)\right)} \bmod \left(\sqrt{\cos x}\right)\right) \cdot e^{\mathsf{neg}\left(x\right)} \]
                4. Step-by-step derivation
                  1. +-commutativeN/A

                    \[\leadsto \left(\color{blue}{\left(x \cdot \left(1 + \frac{1}{2} \cdot x\right) + 1\right)} \bmod \left(\sqrt{\cos x}\right)\right) \cdot e^{\mathsf{neg}\left(x\right)} \]
                  2. lower-fma.f64N/A

                    \[\leadsto \left(\color{blue}{\left(\mathsf{fma}\left(x, 1 + \frac{1}{2} \cdot x, 1\right)\right)} \bmod \left(\sqrt{\cos x}\right)\right) \cdot e^{\mathsf{neg}\left(x\right)} \]
                  3. +-commutativeN/A

                    \[\leadsto \left(\left(\mathsf{fma}\left(x, \color{blue}{\frac{1}{2} \cdot x + 1}, 1\right)\right) \bmod \left(\sqrt{\cos x}\right)\right) \cdot e^{\mathsf{neg}\left(x\right)} \]
                  4. *-commutativeN/A

                    \[\leadsto \left(\left(\mathsf{fma}\left(x, \color{blue}{x \cdot \frac{1}{2}} + 1, 1\right)\right) \bmod \left(\sqrt{\cos x}\right)\right) \cdot e^{\mathsf{neg}\left(x\right)} \]
                  5. lower-fma.f645.5

                    \[\leadsto \left(\left(\mathsf{fma}\left(x, \color{blue}{\mathsf{fma}\left(x, 0.5, 1\right)}, 1\right)\right) \bmod \left(\sqrt{\cos x}\right)\right) \cdot e^{-x} \]
                5. Applied rewrites5.5%

                  \[\leadsto \left(\color{blue}{\left(\mathsf{fma}\left(x, \mathsf{fma}\left(x, 0.5, 1\right), 1\right)\right)} \bmod \left(\sqrt{\cos x}\right)\right) \cdot e^{-x} \]
                6. Taylor expanded in x around inf

                  \[\leadsto \left(\left({x}^{2} \cdot \color{blue}{\left(\frac{1}{2} + \frac{1}{x}\right)}\right) \bmod \left(\sqrt{\cos x}\right)\right) \cdot e^{\mathsf{neg}\left(x\right)} \]
                7. Step-by-step derivation
                  1. Applied rewrites50.6%

                    \[\leadsto \left(\left(\mathsf{fma}\left(x, \color{blue}{x \cdot 0.5}, x\right)\right) \bmod \left(\sqrt{\cos x}\right)\right) \cdot e^{-x} \]
                  2. Taylor expanded in x around 0

                    \[\leadsto \left(\left(\mathsf{fma}\left(x, x \cdot \frac{1}{2}, x\right)\right) \bmod \color{blue}{1}\right) \cdot e^{\mathsf{neg}\left(x\right)} \]
                  3. Step-by-step derivation
                    1. Applied rewrites50.6%

                      \[\leadsto \left(\left(\mathsf{fma}\left(x, x \cdot 0.5, x\right)\right) \bmod \color{blue}{1}\right) \cdot e^{-x} \]

                    if 1e-3 < (*.f64 (fmod.f64 (exp.f64 x) (sqrt.f64 (cos.f64 x))) (exp.f64 (neg.f64 x)))

                    1. Initial program 12.5%

                      \[\left(\left(e^{x}\right) \bmod \left(\sqrt{\cos x}\right)\right) \cdot e^{-x} \]
                    2. Add Preprocessing
                    3. Taylor expanded in x around 0

                      \[\leadsto \left(\left(e^{x}\right) \bmod \color{blue}{1}\right) \cdot e^{\mathsf{neg}\left(x\right)} \]
                    4. Step-by-step derivation
                      1. Applied rewrites11.1%

                        \[\leadsto \left(\left(e^{x}\right) \bmod \color{blue}{1}\right) \cdot e^{-x} \]
                      2. Taylor expanded in x around 0

                        \[\leadsto \left(\color{blue}{\left(1 + x\right)} \bmod 1\right) \cdot e^{\mathsf{neg}\left(x\right)} \]
                      3. Step-by-step derivation
                        1. +-commutativeN/A

                          \[\leadsto \left(\color{blue}{\left(x + 1\right)} \bmod 1\right) \cdot e^{\mathsf{neg}\left(x\right)} \]
                        2. lower-+.f6494.1

                          \[\leadsto \left(\color{blue}{\left(x + 1\right)} \bmod 1\right) \cdot e^{-x} \]
                      4. Applied rewrites94.1%

                        \[\leadsto \left(\color{blue}{\left(x + 1\right)} \bmod 1\right) \cdot e^{-x} \]
                      5. Step-by-step derivation
                        1. lift-*.f64N/A

                          \[\leadsto \color{blue}{\left(\left(x + 1\right) \bmod 1\right) \cdot e^{\mathsf{neg}\left(x\right)}} \]
                        2. lift-exp.f64N/A

                          \[\leadsto \left(\left(x + 1\right) \bmod 1\right) \cdot \color{blue}{e^{\mathsf{neg}\left(x\right)}} \]
                        3. lift-neg.f64N/A

                          \[\leadsto \left(\left(x + 1\right) \bmod 1\right) \cdot e^{\color{blue}{\mathsf{neg}\left(x\right)}} \]
                        4. exp-negN/A

                          \[\leadsto \left(\left(x + 1\right) \bmod 1\right) \cdot \color{blue}{\frac{1}{e^{x}}} \]
                        5. un-div-invN/A

                          \[\leadsto \color{blue}{\frac{\left(\left(x + 1\right) \bmod 1\right)}{e^{x}}} \]
                        6. lower-/.f64N/A

                          \[\leadsto \color{blue}{\frac{\left(\left(x + 1\right) \bmod 1\right)}{e^{x}}} \]
                        7. lift-exp.f6494.2

                          \[\leadsto \frac{\left(\left(x + 1\right) \bmod 1\right)}{\color{blue}{e^{x}}} \]
                      6. Applied rewrites94.2%

                        \[\leadsto \color{blue}{\frac{\left(\left(x + 1\right) \bmod 1\right)}{e^{x}}} \]
                    5. Recombined 2 regimes into one program.
                    6. Final simplification60.4%

                      \[\leadsto \begin{array}{l} \mathbf{if}\;e^{-x} \cdot \left(\left(e^{x}\right) \bmod \left(\sqrt{\cos x}\right)\right) \leq 0.001:\\ \;\;\;\;e^{-x} \cdot \left(\left(\mathsf{fma}\left(x, x \cdot 0.5, x\right)\right) \bmod 1\right)\\ \mathbf{else}:\\ \;\;\;\;\frac{\left(\left(x + 1\right) \bmod 1\right)}{e^{x}}\\ \end{array} \]
                    7. Add Preprocessing

                    Reproduce

                    ?
                    herbie shell --seed 2024230 
                    (FPCore (x)
                      :name "expfmod (used to be hard to sample)"
                      :precision binary64
                      (* (fmod (exp x) (sqrt (cos x))) (exp (- x))))