bug500, discussion (missed optimization)

Percentage Accurate: 51.8% → 96.6%
Time: 12.0s
Alternatives: 5
Speedup: 19.3×

Specification

?
\[\begin{array}{l} \\ \log \left(\frac{\sinh x}{x}\right) \end{array} \]
(FPCore (x) :precision binary64 (log (/ (sinh x) x)))
double code(double x) {
	return log((sinh(x) / x));
}
real(8) function code(x)
    real(8), intent (in) :: x
    code = log((sinh(x) / x))
end function
public static double code(double x) {
	return Math.log((Math.sinh(x) / x));
}
def code(x):
	return math.log((math.sinh(x) / x))
function code(x)
	return log(Float64(sinh(x) / x))
end
function tmp = code(x)
	tmp = log((sinh(x) / x));
end
code[x_] := N[Log[N[(N[Sinh[x], $MachinePrecision] / x), $MachinePrecision]], $MachinePrecision]
\begin{array}{l}

\\
\log \left(\frac{\sinh x}{x}\right)
\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: 51.8% accurate, 1.0× speedup?

\[\begin{array}{l} \\ \log \left(\frac{\sinh x}{x}\right) \end{array} \]
(FPCore (x) :precision binary64 (log (/ (sinh x) x)))
double code(double x) {
	return log((sinh(x) / x));
}
real(8) function code(x)
    real(8), intent (in) :: x
    code = log((sinh(x) / x))
end function
public static double code(double x) {
	return Math.log((Math.sinh(x) / x));
}
def code(x):
	return math.log((math.sinh(x) / x))
function code(x)
	return log(Float64(sinh(x) / x))
end
function tmp = code(x)
	tmp = log((sinh(x) / x));
end
code[x_] := N[Log[N[(N[Sinh[x], $MachinePrecision] / x), $MachinePrecision]], $MachinePrecision]
\begin{array}{l}

\\
\log \left(\frac{\sinh x}{x}\right)
\end{array}

Alternative 1: 96.6% accurate, 0.9× speedup?

\[\begin{array}{l} \\ \mathsf{fma}\left({x}^{6}, 1.7146776406035666 \cdot 10^{-7}, 0.004629629629629629\right) \cdot \left(\frac{x}{\mathsf{fma}\left(3.08641975308642 \cdot 10^{-5}, {x}^{4}, 0.027777777777777776 - -0.000925925925925926 \cdot \left(x \cdot x\right)\right)} \cdot x\right) \end{array} \]
(FPCore (x)
 :precision binary64
 (*
  (fma (pow x 6.0) 1.7146776406035666e-7 0.004629629629629629)
  (*
   (/
    x
    (fma
     3.08641975308642e-5
     (pow x 4.0)
     (- 0.027777777777777776 (* -0.000925925925925926 (* x x)))))
   x)))
double code(double x) {
	return fma(pow(x, 6.0), 1.7146776406035666e-7, 0.004629629629629629) * ((x / fma(3.08641975308642e-5, pow(x, 4.0), (0.027777777777777776 - (-0.000925925925925926 * (x * x))))) * x);
}
function code(x)
	return Float64(fma((x ^ 6.0), 1.7146776406035666e-7, 0.004629629629629629) * Float64(Float64(x / fma(3.08641975308642e-5, (x ^ 4.0), Float64(0.027777777777777776 - Float64(-0.000925925925925926 * Float64(x * x))))) * x))
end
code[x_] := N[(N[(N[Power[x, 6.0], $MachinePrecision] * 1.7146776406035666e-7 + 0.004629629629629629), $MachinePrecision] * N[(N[(x / N[(3.08641975308642e-5 * N[Power[x, 4.0], $MachinePrecision] + N[(0.027777777777777776 - N[(-0.000925925925925926 * N[(x * x), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision] * x), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}

\\
\mathsf{fma}\left({x}^{6}, 1.7146776406035666 \cdot 10^{-7}, 0.004629629629629629\right) \cdot \left(\frac{x}{\mathsf{fma}\left(3.08641975308642 \cdot 10^{-5}, {x}^{4}, 0.027777777777777776 - -0.000925925925925926 \cdot \left(x \cdot x\right)\right)} \cdot x\right)
\end{array}
Derivation
  1. Initial program 47.4%

    \[\log \left(\frac{\sinh x}{x}\right) \]
  2. Add Preprocessing
  3. Taylor expanded in x around 0

    \[\leadsto \color{blue}{{x}^{2} \cdot \left(\frac{1}{6} + \frac{-1}{180} \cdot {x}^{2}\right)} \]
  4. Step-by-step derivation
    1. *-commutativeN/A

      \[\leadsto \color{blue}{\left(\frac{1}{6} + \frac{-1}{180} \cdot {x}^{2}\right) \cdot {x}^{2}} \]
    2. unpow2N/A

      \[\leadsto \left(\frac{1}{6} + \frac{-1}{180} \cdot {x}^{2}\right) \cdot \color{blue}{\left(x \cdot x\right)} \]
    3. associate-*r*N/A

      \[\leadsto \color{blue}{\left(\left(\frac{1}{6} + \frac{-1}{180} \cdot {x}^{2}\right) \cdot x\right) \cdot x} \]
    4. lower-*.f64N/A

      \[\leadsto \color{blue}{\left(\left(\frac{1}{6} + \frac{-1}{180} \cdot {x}^{2}\right) \cdot x\right) \cdot x} \]
    5. lower-*.f64N/A

      \[\leadsto \color{blue}{\left(\left(\frac{1}{6} + \frac{-1}{180} \cdot {x}^{2}\right) \cdot x\right)} \cdot x \]
    6. +-commutativeN/A

      \[\leadsto \left(\color{blue}{\left(\frac{-1}{180} \cdot {x}^{2} + \frac{1}{6}\right)} \cdot x\right) \cdot x \]
    7. lower-fma.f64N/A

      \[\leadsto \left(\color{blue}{\mathsf{fma}\left(\frac{-1}{180}, {x}^{2}, \frac{1}{6}\right)} \cdot x\right) \cdot x \]
    8. unpow2N/A

      \[\leadsto \left(\mathsf{fma}\left(\frac{-1}{180}, \color{blue}{x \cdot x}, \frac{1}{6}\right) \cdot x\right) \cdot x \]
    9. lower-*.f6495.2

      \[\leadsto \left(\mathsf{fma}\left(-0.005555555555555556, \color{blue}{x \cdot x}, 0.16666666666666666\right) \cdot x\right) \cdot x \]
  5. Applied rewrites95.2%

    \[\leadsto \color{blue}{\left(\mathsf{fma}\left(-0.005555555555555556, x \cdot x, 0.16666666666666666\right) \cdot x\right) \cdot x} \]
  6. Step-by-step derivation
    1. Applied rewrites95.2%

      \[\leadsto \mathsf{fma}\left(-0.005555555555555556 \cdot \left(x \cdot x\right), x, 0.16666666666666666 \cdot x\right) \cdot x \]
    2. Applied rewrites95.6%

      \[\leadsto \mathsf{fma}\left({x}^{6}, 1.7146776406035666 \cdot 10^{-7}, 0.004629629629629629\right) \cdot \color{blue}{\left(\frac{x}{\mathsf{fma}\left(3.08641975308642 \cdot 10^{-5}, {x}^{4}, 0.027777777777777776 - -0.000925925925925926 \cdot \left(x \cdot x\right)\right)} \cdot x\right)} \]
    3. Add Preprocessing

    Alternative 2: 96.6% accurate, 1.5× speedup?

    \[\begin{array}{l} \\ \frac{0.004629629629629629 \cdot x}{\mathsf{fma}\left({x}^{4}, 3.08641975308642 \cdot 10^{-5}, 0.027777777777777776 - \left(x \cdot x\right) \cdot -0.000925925925925926\right)} \cdot x \end{array} \]
    (FPCore (x)
     :precision binary64
     (*
      (/
       (* 0.004629629629629629 x)
       (fma
        (pow x 4.0)
        3.08641975308642e-5
        (- 0.027777777777777776 (* (* x x) -0.000925925925925926))))
      x))
    double code(double x) {
    	return ((0.004629629629629629 * x) / fma(pow(x, 4.0), 3.08641975308642e-5, (0.027777777777777776 - ((x * x) * -0.000925925925925926)))) * x;
    }
    
    function code(x)
    	return Float64(Float64(Float64(0.004629629629629629 * x) / fma((x ^ 4.0), 3.08641975308642e-5, Float64(0.027777777777777776 - Float64(Float64(x * x) * -0.000925925925925926)))) * x)
    end
    
    code[x_] := N[(N[(N[(0.004629629629629629 * x), $MachinePrecision] / N[(N[Power[x, 4.0], $MachinePrecision] * 3.08641975308642e-5 + N[(0.027777777777777776 - N[(N[(x * x), $MachinePrecision] * -0.000925925925925926), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision] * x), $MachinePrecision]
    
    \begin{array}{l}
    
    \\
    \frac{0.004629629629629629 \cdot x}{\mathsf{fma}\left({x}^{4}, 3.08641975308642 \cdot 10^{-5}, 0.027777777777777776 - \left(x \cdot x\right) \cdot -0.000925925925925926\right)} \cdot x
    \end{array}
    
    Derivation
    1. Initial program 47.4%

      \[\log \left(\frac{\sinh x}{x}\right) \]
    2. Add Preprocessing
    3. Taylor expanded in x around 0

      \[\leadsto \color{blue}{{x}^{2} \cdot \left(\frac{1}{6} + \frac{-1}{180} \cdot {x}^{2}\right)} \]
    4. Step-by-step derivation
      1. *-commutativeN/A

        \[\leadsto \color{blue}{\left(\frac{1}{6} + \frac{-1}{180} \cdot {x}^{2}\right) \cdot {x}^{2}} \]
      2. unpow2N/A

        \[\leadsto \left(\frac{1}{6} + \frac{-1}{180} \cdot {x}^{2}\right) \cdot \color{blue}{\left(x \cdot x\right)} \]
      3. associate-*r*N/A

        \[\leadsto \color{blue}{\left(\left(\frac{1}{6} + \frac{-1}{180} \cdot {x}^{2}\right) \cdot x\right) \cdot x} \]
      4. lower-*.f64N/A

        \[\leadsto \color{blue}{\left(\left(\frac{1}{6} + \frac{-1}{180} \cdot {x}^{2}\right) \cdot x\right) \cdot x} \]
      5. lower-*.f64N/A

        \[\leadsto \color{blue}{\left(\left(\frac{1}{6} + \frac{-1}{180} \cdot {x}^{2}\right) \cdot x\right)} \cdot x \]
      6. +-commutativeN/A

        \[\leadsto \left(\color{blue}{\left(\frac{-1}{180} \cdot {x}^{2} + \frac{1}{6}\right)} \cdot x\right) \cdot x \]
      7. lower-fma.f64N/A

        \[\leadsto \left(\color{blue}{\mathsf{fma}\left(\frac{-1}{180}, {x}^{2}, \frac{1}{6}\right)} \cdot x\right) \cdot x \]
      8. unpow2N/A

        \[\leadsto \left(\mathsf{fma}\left(\frac{-1}{180}, \color{blue}{x \cdot x}, \frac{1}{6}\right) \cdot x\right) \cdot x \]
      9. lower-*.f6495.2

        \[\leadsto \left(\mathsf{fma}\left(-0.005555555555555556, \color{blue}{x \cdot x}, 0.16666666666666666\right) \cdot x\right) \cdot x \]
    5. Applied rewrites95.2%

      \[\leadsto \color{blue}{\left(\mathsf{fma}\left(-0.005555555555555556, x \cdot x, 0.16666666666666666\right) \cdot x\right) \cdot x} \]
    6. Step-by-step derivation
      1. Applied rewrites95.2%

        \[\leadsto \frac{\mathsf{fma}\left(-1.7146776406035666 \cdot 10^{-7}, {x}^{6}, 0.004629629629629629\right) \cdot x}{\mathsf{fma}\left({x}^{4}, 3.08641975308642 \cdot 10^{-5}, 0.027777777777777776 - \left(x \cdot x\right) \cdot -0.000925925925925926\right)} \cdot x \]
      2. Taylor expanded in x around 0

        \[\leadsto \frac{\frac{1}{216} \cdot x}{\mathsf{fma}\left({x}^{4}, \frac{1}{32400}, \frac{1}{36} - \left(x \cdot x\right) \cdot \frac{-1}{1080}\right)} \cdot x \]
      3. Step-by-step derivation
        1. Applied rewrites95.6%

          \[\leadsto \frac{0.004629629629629629 \cdot x}{\mathsf{fma}\left({x}^{4}, 3.08641975308642 \cdot 10^{-5}, 0.027777777777777776 - \left(x \cdot x\right) \cdot -0.000925925925925926\right)} \cdot x \]
        2. Add Preprocessing

        Alternative 3: 96.8% accurate, 6.1× speedup?

        \[\begin{array}{l} \\ \left(\mathsf{fma}\left(0.0003527336860670194 \cdot \left(x \cdot x\right) - 0.005555555555555556, x \cdot x, 0.16666666666666666\right) \cdot x\right) \cdot x \end{array} \]
        (FPCore (x)
         :precision binary64
         (*
          (*
           (fma
            (- (* 0.0003527336860670194 (* x x)) 0.005555555555555556)
            (* x x)
            0.16666666666666666)
           x)
          x))
        double code(double x) {
        	return (fma(((0.0003527336860670194 * (x * x)) - 0.005555555555555556), (x * x), 0.16666666666666666) * x) * x;
        }
        
        function code(x)
        	return Float64(Float64(fma(Float64(Float64(0.0003527336860670194 * Float64(x * x)) - 0.005555555555555556), Float64(x * x), 0.16666666666666666) * x) * x)
        end
        
        code[x_] := N[(N[(N[(N[(N[(0.0003527336860670194 * N[(x * x), $MachinePrecision]), $MachinePrecision] - 0.005555555555555556), $MachinePrecision] * N[(x * x), $MachinePrecision] + 0.16666666666666666), $MachinePrecision] * x), $MachinePrecision] * x), $MachinePrecision]
        
        \begin{array}{l}
        
        \\
        \left(\mathsf{fma}\left(0.0003527336860670194 \cdot \left(x \cdot x\right) - 0.005555555555555556, x \cdot x, 0.16666666666666666\right) \cdot x\right) \cdot x
        \end{array}
        
        Derivation
        1. Initial program 47.4%

          \[\log \left(\frac{\sinh x}{x}\right) \]
        2. Add Preprocessing
        3. Taylor expanded in x around 0

          \[\leadsto \color{blue}{{x}^{2} \cdot \left(\frac{1}{6} + {x}^{2} \cdot \left(\frac{1}{2835} \cdot {x}^{2} - \frac{1}{180}\right)\right)} \]
        4. Step-by-step derivation
          1. unpow2N/A

            \[\leadsto \color{blue}{\left(x \cdot x\right)} \cdot \left(\frac{1}{6} + {x}^{2} \cdot \left(\frac{1}{2835} \cdot {x}^{2} - \frac{1}{180}\right)\right) \]
          2. associate-*l*N/A

            \[\leadsto \color{blue}{x \cdot \left(x \cdot \left(\frac{1}{6} + {x}^{2} \cdot \left(\frac{1}{2835} \cdot {x}^{2} - \frac{1}{180}\right)\right)\right)} \]
          3. *-commutativeN/A

            \[\leadsto \color{blue}{\left(x \cdot \left(\frac{1}{6} + {x}^{2} \cdot \left(\frac{1}{2835} \cdot {x}^{2} - \frac{1}{180}\right)\right)\right) \cdot x} \]
          4. lower-*.f64N/A

            \[\leadsto \color{blue}{\left(x \cdot \left(\frac{1}{6} + {x}^{2} \cdot \left(\frac{1}{2835} \cdot {x}^{2} - \frac{1}{180}\right)\right)\right) \cdot x} \]
          5. *-commutativeN/A

            \[\leadsto \color{blue}{\left(\left(\frac{1}{6} + {x}^{2} \cdot \left(\frac{1}{2835} \cdot {x}^{2} - \frac{1}{180}\right)\right) \cdot x\right)} \cdot x \]
          6. lower-*.f64N/A

            \[\leadsto \color{blue}{\left(\left(\frac{1}{6} + {x}^{2} \cdot \left(\frac{1}{2835} \cdot {x}^{2} - \frac{1}{180}\right)\right) \cdot x\right)} \cdot x \]
          7. +-commutativeN/A

            \[\leadsto \left(\color{blue}{\left({x}^{2} \cdot \left(\frac{1}{2835} \cdot {x}^{2} - \frac{1}{180}\right) + \frac{1}{6}\right)} \cdot x\right) \cdot x \]
          8. *-commutativeN/A

            \[\leadsto \left(\left(\color{blue}{\left(\frac{1}{2835} \cdot {x}^{2} - \frac{1}{180}\right) \cdot {x}^{2}} + \frac{1}{6}\right) \cdot x\right) \cdot x \]
          9. lower-fma.f64N/A

            \[\leadsto \left(\color{blue}{\mathsf{fma}\left(\frac{1}{2835} \cdot {x}^{2} - \frac{1}{180}, {x}^{2}, \frac{1}{6}\right)} \cdot x\right) \cdot x \]
          10. lower--.f64N/A

            \[\leadsto \left(\mathsf{fma}\left(\color{blue}{\frac{1}{2835} \cdot {x}^{2} - \frac{1}{180}}, {x}^{2}, \frac{1}{6}\right) \cdot x\right) \cdot x \]
          11. lower-*.f64N/A

            \[\leadsto \left(\mathsf{fma}\left(\color{blue}{\frac{1}{2835} \cdot {x}^{2}} - \frac{1}{180}, {x}^{2}, \frac{1}{6}\right) \cdot x\right) \cdot x \]
          12. unpow2N/A

            \[\leadsto \left(\mathsf{fma}\left(\frac{1}{2835} \cdot \color{blue}{\left(x \cdot x\right)} - \frac{1}{180}, {x}^{2}, \frac{1}{6}\right) \cdot x\right) \cdot x \]
          13. lower-*.f64N/A

            \[\leadsto \left(\mathsf{fma}\left(\frac{1}{2835} \cdot \color{blue}{\left(x \cdot x\right)} - \frac{1}{180}, {x}^{2}, \frac{1}{6}\right) \cdot x\right) \cdot x \]
          14. unpow2N/A

            \[\leadsto \left(\mathsf{fma}\left(\frac{1}{2835} \cdot \left(x \cdot x\right) - \frac{1}{180}, \color{blue}{x \cdot x}, \frac{1}{6}\right) \cdot x\right) \cdot x \]
          15. lower-*.f6495.6

            \[\leadsto \left(\mathsf{fma}\left(0.0003527336860670194 \cdot \left(x \cdot x\right) - 0.005555555555555556, \color{blue}{x \cdot x}, 0.16666666666666666\right) \cdot x\right) \cdot x \]
        5. Applied rewrites95.6%

          \[\leadsto \color{blue}{\left(\mathsf{fma}\left(0.0003527336860670194 \cdot \left(x \cdot x\right) - 0.005555555555555556, x \cdot x, 0.16666666666666666\right) \cdot x\right) \cdot x} \]
        6. Add Preprocessing

        Alternative 4: 96.1% accurate, 19.3× speedup?

        \[\begin{array}{l} \\ \left(0.16666666666666666 \cdot x\right) \cdot x \end{array} \]
        (FPCore (x) :precision binary64 (* (* 0.16666666666666666 x) x))
        double code(double x) {
        	return (0.16666666666666666 * x) * x;
        }
        
        real(8) function code(x)
            real(8), intent (in) :: x
            code = (0.16666666666666666d0 * x) * x
        end function
        
        public static double code(double x) {
        	return (0.16666666666666666 * x) * x;
        }
        
        def code(x):
        	return (0.16666666666666666 * x) * x
        
        function code(x)
        	return Float64(Float64(0.16666666666666666 * x) * x)
        end
        
        function tmp = code(x)
        	tmp = (0.16666666666666666 * x) * x;
        end
        
        code[x_] := N[(N[(0.16666666666666666 * x), $MachinePrecision] * x), $MachinePrecision]
        
        \begin{array}{l}
        
        \\
        \left(0.16666666666666666 \cdot x\right) \cdot x
        \end{array}
        
        Derivation
        1. Initial program 47.4%

          \[\log \left(\frac{\sinh x}{x}\right) \]
        2. Add Preprocessing
        3. Taylor expanded in x around 0

          \[\leadsto \color{blue}{{x}^{2} \cdot \left(\frac{1}{6} + {x}^{2} \cdot \left(\frac{1}{2835} \cdot {x}^{2} - \frac{1}{180}\right)\right)} \]
        4. Step-by-step derivation
          1. unpow2N/A

            \[\leadsto \color{blue}{\left(x \cdot x\right)} \cdot \left(\frac{1}{6} + {x}^{2} \cdot \left(\frac{1}{2835} \cdot {x}^{2} - \frac{1}{180}\right)\right) \]
          2. associate-*l*N/A

            \[\leadsto \color{blue}{x \cdot \left(x \cdot \left(\frac{1}{6} + {x}^{2} \cdot \left(\frac{1}{2835} \cdot {x}^{2} - \frac{1}{180}\right)\right)\right)} \]
          3. *-commutativeN/A

            \[\leadsto \color{blue}{\left(x \cdot \left(\frac{1}{6} + {x}^{2} \cdot \left(\frac{1}{2835} \cdot {x}^{2} - \frac{1}{180}\right)\right)\right) \cdot x} \]
          4. lower-*.f64N/A

            \[\leadsto \color{blue}{\left(x \cdot \left(\frac{1}{6} + {x}^{2} \cdot \left(\frac{1}{2835} \cdot {x}^{2} - \frac{1}{180}\right)\right)\right) \cdot x} \]
          5. *-commutativeN/A

            \[\leadsto \color{blue}{\left(\left(\frac{1}{6} + {x}^{2} \cdot \left(\frac{1}{2835} \cdot {x}^{2} - \frac{1}{180}\right)\right) \cdot x\right)} \cdot x \]
          6. lower-*.f64N/A

            \[\leadsto \color{blue}{\left(\left(\frac{1}{6} + {x}^{2} \cdot \left(\frac{1}{2835} \cdot {x}^{2} - \frac{1}{180}\right)\right) \cdot x\right)} \cdot x \]
          7. +-commutativeN/A

            \[\leadsto \left(\color{blue}{\left({x}^{2} \cdot \left(\frac{1}{2835} \cdot {x}^{2} - \frac{1}{180}\right) + \frac{1}{6}\right)} \cdot x\right) \cdot x \]
          8. *-commutativeN/A

            \[\leadsto \left(\left(\color{blue}{\left(\frac{1}{2835} \cdot {x}^{2} - \frac{1}{180}\right) \cdot {x}^{2}} + \frac{1}{6}\right) \cdot x\right) \cdot x \]
          9. lower-fma.f64N/A

            \[\leadsto \left(\color{blue}{\mathsf{fma}\left(\frac{1}{2835} \cdot {x}^{2} - \frac{1}{180}, {x}^{2}, \frac{1}{6}\right)} \cdot x\right) \cdot x \]
          10. lower--.f64N/A

            \[\leadsto \left(\mathsf{fma}\left(\color{blue}{\frac{1}{2835} \cdot {x}^{2} - \frac{1}{180}}, {x}^{2}, \frac{1}{6}\right) \cdot x\right) \cdot x \]
          11. lower-*.f64N/A

            \[\leadsto \left(\mathsf{fma}\left(\color{blue}{\frac{1}{2835} \cdot {x}^{2}} - \frac{1}{180}, {x}^{2}, \frac{1}{6}\right) \cdot x\right) \cdot x \]
          12. unpow2N/A

            \[\leadsto \left(\mathsf{fma}\left(\frac{1}{2835} \cdot \color{blue}{\left(x \cdot x\right)} - \frac{1}{180}, {x}^{2}, \frac{1}{6}\right) \cdot x\right) \cdot x \]
          13. lower-*.f64N/A

            \[\leadsto \left(\mathsf{fma}\left(\frac{1}{2835} \cdot \color{blue}{\left(x \cdot x\right)} - \frac{1}{180}, {x}^{2}, \frac{1}{6}\right) \cdot x\right) \cdot x \]
          14. unpow2N/A

            \[\leadsto \left(\mathsf{fma}\left(\frac{1}{2835} \cdot \left(x \cdot x\right) - \frac{1}{180}, \color{blue}{x \cdot x}, \frac{1}{6}\right) \cdot x\right) \cdot x \]
          15. lower-*.f6495.6

            \[\leadsto \left(\mathsf{fma}\left(0.0003527336860670194 \cdot \left(x \cdot x\right) - 0.005555555555555556, \color{blue}{x \cdot x}, 0.16666666666666666\right) \cdot x\right) \cdot x \]
        5. Applied rewrites95.6%

          \[\leadsto \color{blue}{\left(\mathsf{fma}\left(0.0003527336860670194 \cdot \left(x \cdot x\right) - 0.005555555555555556, x \cdot x, 0.16666666666666666\right) \cdot x\right) \cdot x} \]
        6. Taylor expanded in x around 0

          \[\leadsto \left(\frac{1}{6} \cdot x\right) \cdot x \]
        7. Step-by-step derivation
          1. Applied rewrites95.3%

            \[\leadsto \left(0.16666666666666666 \cdot x\right) \cdot x \]
          2. Add Preprocessing

          Alternative 5: 96.1% accurate, 19.3× speedup?

          \[\begin{array}{l} \\ \left(x \cdot x\right) \cdot 0.16666666666666666 \end{array} \]
          (FPCore (x) :precision binary64 (* (* x x) 0.16666666666666666))
          double code(double x) {
          	return (x * x) * 0.16666666666666666;
          }
          
          real(8) function code(x)
              real(8), intent (in) :: x
              code = (x * x) * 0.16666666666666666d0
          end function
          
          public static double code(double x) {
          	return (x * x) * 0.16666666666666666;
          }
          
          def code(x):
          	return (x * x) * 0.16666666666666666
          
          function code(x)
          	return Float64(Float64(x * x) * 0.16666666666666666)
          end
          
          function tmp = code(x)
          	tmp = (x * x) * 0.16666666666666666;
          end
          
          code[x_] := N[(N[(x * x), $MachinePrecision] * 0.16666666666666666), $MachinePrecision]
          
          \begin{array}{l}
          
          \\
          \left(x \cdot x\right) \cdot 0.16666666666666666
          \end{array}
          
          Derivation
          1. Initial program 47.4%

            \[\log \left(\frac{\sinh x}{x}\right) \]
          2. Add Preprocessing
          3. Taylor expanded in x around 0

            \[\leadsto \color{blue}{\frac{1}{6} \cdot {x}^{2}} \]
          4. Step-by-step derivation
            1. *-commutativeN/A

              \[\leadsto \color{blue}{{x}^{2} \cdot \frac{1}{6}} \]
            2. lower-*.f64N/A

              \[\leadsto \color{blue}{{x}^{2} \cdot \frac{1}{6}} \]
            3. unpow2N/A

              \[\leadsto \color{blue}{\left(x \cdot x\right)} \cdot \frac{1}{6} \]
            4. lower-*.f6495.2

              \[\leadsto \color{blue}{\left(x \cdot x\right)} \cdot 0.16666666666666666 \]
          5. Applied rewrites95.2%

            \[\leadsto \color{blue}{\left(x \cdot x\right) \cdot 0.16666666666666666} \]
          6. Add Preprocessing

          Developer Target 1: 97.7% accurate, 1.0× speedup?

          \[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;\left|x\right| < 0.085:\\ \;\;\;\;\left(x \cdot x\right) \cdot \mathsf{fma}\left(\mathsf{fma}\left(\mathsf{fma}\left(-2.6455026455026456 \cdot 10^{-5}, x \cdot x, 0.0003527336860670194\right), x \cdot x, -0.005555555555555556\right), x \cdot x, 0.16666666666666666\right)\\ \mathbf{else}:\\ \;\;\;\;\log \left(\frac{\sinh x}{x}\right)\\ \end{array} \end{array} \]
          (FPCore (x)
           :precision binary64
           (if (< (fabs x) 0.085)
             (*
              (* x x)
              (fma
               (fma
                (fma -2.6455026455026456e-5 (* x x) 0.0003527336860670194)
                (* x x)
                -0.005555555555555556)
               (* x x)
               0.16666666666666666))
             (log (/ (sinh x) x))))
          double code(double x) {
          	double tmp;
          	if (fabs(x) < 0.085) {
          		tmp = (x * x) * fma(fma(fma(-2.6455026455026456e-5, (x * x), 0.0003527336860670194), (x * x), -0.005555555555555556), (x * x), 0.16666666666666666);
          	} else {
          		tmp = log((sinh(x) / x));
          	}
          	return tmp;
          }
          
          function code(x)
          	tmp = 0.0
          	if (abs(x) < 0.085)
          		tmp = Float64(Float64(x * x) * fma(fma(fma(-2.6455026455026456e-5, Float64(x * x), 0.0003527336860670194), Float64(x * x), -0.005555555555555556), Float64(x * x), 0.16666666666666666));
          	else
          		tmp = log(Float64(sinh(x) / x));
          	end
          	return tmp
          end
          
          code[x_] := If[Less[N[Abs[x], $MachinePrecision], 0.085], N[(N[(x * x), $MachinePrecision] * N[(N[(N[(-2.6455026455026456e-5 * N[(x * x), $MachinePrecision] + 0.0003527336860670194), $MachinePrecision] * N[(x * x), $MachinePrecision] + -0.005555555555555556), $MachinePrecision] * N[(x * x), $MachinePrecision] + 0.16666666666666666), $MachinePrecision]), $MachinePrecision], N[Log[N[(N[Sinh[x], $MachinePrecision] / x), $MachinePrecision]], $MachinePrecision]]
          
          \begin{array}{l}
          
          \\
          \begin{array}{l}
          \mathbf{if}\;\left|x\right| < 0.085:\\
          \;\;\;\;\left(x \cdot x\right) \cdot \mathsf{fma}\left(\mathsf{fma}\left(\mathsf{fma}\left(-2.6455026455026456 \cdot 10^{-5}, x \cdot x, 0.0003527336860670194\right), x \cdot x, -0.005555555555555556\right), x \cdot x, 0.16666666666666666\right)\\
          
          \mathbf{else}:\\
          \;\;\;\;\log \left(\frac{\sinh x}{x}\right)\\
          
          
          \end{array}
          \end{array}
          

          Reproduce

          ?
          herbie shell --seed 2024337 
          (FPCore (x)
            :name "bug500, discussion (missed optimization)"
            :precision binary64
          
            :alt
            (! :herbie-platform default (if (< (fabs x) 17/200) (let ((x2 (* x x))) (* x2 (fma (fma (fma -1/37800 x2 1/2835) x2 -1/180) x2 1/6))) (log (/ (sinh x) x))))
          
            (log (/ (sinh x) x)))