bug500 (missed optimization)

Percentage Accurate: 69.4% → 98.6%
Time: 4.6s
Alternatives: 9
Speedup: 6.5×

Specification

?
\[-1000 < x \land x < 1000\]
\[\begin{array}{l} \\ \sin x - x \end{array} \]
(FPCore (x) :precision binary64 (- (sin x) x))
double code(double x) {
	return sin(x) - x;
}
module fmin_fmax_functions
    implicit none
    private
    public fmax
    public fmin

    interface fmax
        module procedure fmax88
        module procedure fmax44
        module procedure fmax84
        module procedure fmax48
    end interface
    interface fmin
        module procedure fmin88
        module procedure fmin44
        module procedure fmin84
        module procedure fmin48
    end interface
contains
    real(8) function fmax88(x, y) result (res)
        real(8), intent (in) :: x
        real(8), intent (in) :: y
        res = merge(y, merge(x, max(x, y), y /= y), x /= x)
    end function
    real(4) function fmax44(x, y) result (res)
        real(4), intent (in) :: x
        real(4), intent (in) :: y
        res = merge(y, merge(x, max(x, y), y /= y), x /= x)
    end function
    real(8) function fmax84(x, y) result(res)
        real(8), intent (in) :: x
        real(4), intent (in) :: y
        res = merge(dble(y), merge(x, max(x, dble(y)), y /= y), x /= x)
    end function
    real(8) function fmax48(x, y) result(res)
        real(4), intent (in) :: x
        real(8), intent (in) :: y
        res = merge(y, merge(dble(x), max(dble(x), y), y /= y), x /= x)
    end function
    real(8) function fmin88(x, y) result (res)
        real(8), intent (in) :: x
        real(8), intent (in) :: y
        res = merge(y, merge(x, min(x, y), y /= y), x /= x)
    end function
    real(4) function fmin44(x, y) result (res)
        real(4), intent (in) :: x
        real(4), intent (in) :: y
        res = merge(y, merge(x, min(x, y), y /= y), x /= x)
    end function
    real(8) function fmin84(x, y) result(res)
        real(8), intent (in) :: x
        real(4), intent (in) :: y
        res = merge(dble(y), merge(x, min(x, dble(y)), y /= y), x /= x)
    end function
    real(8) function fmin48(x, y) result(res)
        real(4), intent (in) :: x
        real(8), intent (in) :: y
        res = merge(y, merge(dble(x), min(dble(x), y), y /= y), x /= x)
    end function
end module

real(8) function code(x)
use fmin_fmax_functions
    real(8), intent (in) :: x
    code = sin(x) - x
end function
public static double code(double x) {
	return Math.sin(x) - x;
}
def code(x):
	return math.sin(x) - x
function code(x)
	return Float64(sin(x) - x)
end
function tmp = code(x)
	tmp = sin(x) - x;
end
code[x_] := N[(N[Sin[x], $MachinePrecision] - x), $MachinePrecision]
\begin{array}{l}

\\
\sin x - 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 9 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: 69.4% accurate, 1.0× speedup?

\[\begin{array}{l} \\ \sin x - x \end{array} \]
(FPCore (x) :precision binary64 (- (sin x) x))
double code(double x) {
	return sin(x) - x;
}
module fmin_fmax_functions
    implicit none
    private
    public fmax
    public fmin

    interface fmax
        module procedure fmax88
        module procedure fmax44
        module procedure fmax84
        module procedure fmax48
    end interface
    interface fmin
        module procedure fmin88
        module procedure fmin44
        module procedure fmin84
        module procedure fmin48
    end interface
contains
    real(8) function fmax88(x, y) result (res)
        real(8), intent (in) :: x
        real(8), intent (in) :: y
        res = merge(y, merge(x, max(x, y), y /= y), x /= x)
    end function
    real(4) function fmax44(x, y) result (res)
        real(4), intent (in) :: x
        real(4), intent (in) :: y
        res = merge(y, merge(x, max(x, y), y /= y), x /= x)
    end function
    real(8) function fmax84(x, y) result(res)
        real(8), intent (in) :: x
        real(4), intent (in) :: y
        res = merge(dble(y), merge(x, max(x, dble(y)), y /= y), x /= x)
    end function
    real(8) function fmax48(x, y) result(res)
        real(4), intent (in) :: x
        real(8), intent (in) :: y
        res = merge(y, merge(dble(x), max(dble(x), y), y /= y), x /= x)
    end function
    real(8) function fmin88(x, y) result (res)
        real(8), intent (in) :: x
        real(8), intent (in) :: y
        res = merge(y, merge(x, min(x, y), y /= y), x /= x)
    end function
    real(4) function fmin44(x, y) result (res)
        real(4), intent (in) :: x
        real(4), intent (in) :: y
        res = merge(y, merge(x, min(x, y), y /= y), x /= x)
    end function
    real(8) function fmin84(x, y) result(res)
        real(8), intent (in) :: x
        real(4), intent (in) :: y
        res = merge(dble(y), merge(x, min(x, dble(y)), y /= y), x /= x)
    end function
    real(8) function fmin48(x, y) result(res)
        real(4), intent (in) :: x
        real(8), intent (in) :: y
        res = merge(y, merge(dble(x), min(dble(x), y), y /= y), x /= x)
    end function
end module

real(8) function code(x)
use fmin_fmax_functions
    real(8), intent (in) :: x
    code = sin(x) - x
end function
public static double code(double x) {
	return Math.sin(x) - x;
}
def code(x):
	return math.sin(x) - x
function code(x)
	return Float64(sin(x) - x)
end
function tmp = code(x)
	tmp = sin(x) - x;
end
code[x_] := N[(N[Sin[x], $MachinePrecision] - x), $MachinePrecision]
\begin{array}{l}

\\
\sin x - x
\end{array}

Alternative 1: 98.6% accurate, 2.1× speedup?

\[\begin{array}{l} \\ \mathsf{fma}\left(\mathsf{fma}\left(\mathsf{fma}\left(2.7557319223985893 \cdot 10^{-6}, x \cdot x, -0.0001984126984126984\right), x \cdot x, 0.008333333333333333\right), x \cdot x, -0.16666666666666666\right) \cdot \left(\left(x \cdot x\right) \cdot x\right) \end{array} \]
(FPCore (x)
 :precision binary64
 (*
  (fma
   (fma
    (fma 2.7557319223985893e-6 (* x x) -0.0001984126984126984)
    (* x x)
    0.008333333333333333)
   (* x x)
   -0.16666666666666666)
  (* (* x x) x)))
double code(double x) {
	return fma(fma(fma(2.7557319223985893e-6, (x * x), -0.0001984126984126984), (x * x), 0.008333333333333333), (x * x), -0.16666666666666666) * ((x * x) * x);
}
function code(x)
	return Float64(fma(fma(fma(2.7557319223985893e-6, Float64(x * x), -0.0001984126984126984), Float64(x * x), 0.008333333333333333), Float64(x * x), -0.16666666666666666) * Float64(Float64(x * x) * x))
end
code[x_] := N[(N[(N[(N[(2.7557319223985893e-6 * N[(x * x), $MachinePrecision] + -0.0001984126984126984), $MachinePrecision] * N[(x * x), $MachinePrecision] + 0.008333333333333333), $MachinePrecision] * N[(x * x), $MachinePrecision] + -0.16666666666666666), $MachinePrecision] * N[(N[(x * x), $MachinePrecision] * x), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}

\\
\mathsf{fma}\left(\mathsf{fma}\left(\mathsf{fma}\left(2.7557319223985893 \cdot 10^{-6}, x \cdot x, -0.0001984126984126984\right), x \cdot x, 0.008333333333333333\right), x \cdot x, -0.16666666666666666\right) \cdot \left(\left(x \cdot x\right) \cdot x\right)
\end{array}
Derivation
  1. Initial program 68.2%

    \[\sin x - x \]
  2. Add Preprocessing
  3. Taylor expanded in x around 0

    \[\leadsto \color{blue}{{x}^{3} \cdot \left({x}^{2} \cdot \left(\frac{1}{120} + {x}^{2} \cdot \left(\frac{1}{362880} \cdot {x}^{2} - \frac{1}{5040}\right)\right) - \frac{1}{6}\right)} \]
  4. Step-by-step derivation
    1. Applied rewrites99.4%

      \[\leadsto \color{blue}{\mathsf{fma}\left(\mathsf{fma}\left(\mathsf{fma}\left(2.7557319223985893 \cdot 10^{-6}, x \cdot x, -0.0001984126984126984\right), x \cdot x, 0.008333333333333333\right), x \cdot x, -0.16666666666666666\right) \cdot {x}^{3}} \]
    2. Step-by-step derivation
      1. Applied rewrites99.4%

        \[\leadsto \mathsf{fma}\left(\mathsf{fma}\left(\mathsf{fma}\left(2.7557319223985893 \cdot 10^{-6}, x \cdot x, -0.0001984126984126984\right), x \cdot x, 0.008333333333333333\right), x \cdot x, -0.16666666666666666\right) \cdot \left(\left(x \cdot x\right) \cdot \color{blue}{x}\right) \]
      2. Add Preprocessing

      Alternative 2: 98.6% accurate, 2.1× speedup?

      \[\begin{array}{l} \\ \left(\left(\mathsf{fma}\left(\mathsf{fma}\left(\mathsf{fma}\left(2.7557319223985893 \cdot 10^{-6}, x \cdot x, -0.0001984126984126984\right), x \cdot x, 0.008333333333333333\right), x \cdot x, -0.16666666666666666\right) \cdot x\right) \cdot x\right) \cdot x \end{array} \]
      (FPCore (x)
       :precision binary64
       (*
        (*
         (*
          (fma
           (fma
            (fma 2.7557319223985893e-6 (* x x) -0.0001984126984126984)
            (* x x)
            0.008333333333333333)
           (* x x)
           -0.16666666666666666)
          x)
         x)
        x))
      double code(double x) {
      	return ((fma(fma(fma(2.7557319223985893e-6, (x * x), -0.0001984126984126984), (x * x), 0.008333333333333333), (x * x), -0.16666666666666666) * x) * x) * x;
      }
      
      function code(x)
      	return Float64(Float64(Float64(fma(fma(fma(2.7557319223985893e-6, Float64(x * x), -0.0001984126984126984), Float64(x * x), 0.008333333333333333), Float64(x * x), -0.16666666666666666) * x) * x) * x)
      end
      
      code[x_] := N[(N[(N[(N[(N[(N[(2.7557319223985893e-6 * N[(x * x), $MachinePrecision] + -0.0001984126984126984), $MachinePrecision] * N[(x * x), $MachinePrecision] + 0.008333333333333333), $MachinePrecision] * N[(x * x), $MachinePrecision] + -0.16666666666666666), $MachinePrecision] * x), $MachinePrecision] * x), $MachinePrecision] * x), $MachinePrecision]
      
      \begin{array}{l}
      
      \\
      \left(\left(\mathsf{fma}\left(\mathsf{fma}\left(\mathsf{fma}\left(2.7557319223985893 \cdot 10^{-6}, x \cdot x, -0.0001984126984126984\right), x \cdot x, 0.008333333333333333\right), x \cdot x, -0.16666666666666666\right) \cdot x\right) \cdot x\right) \cdot x
      \end{array}
      
      Derivation
      1. Initial program 68.2%

        \[\sin x - x \]
      2. Add Preprocessing
      3. Taylor expanded in x around 0

        \[\leadsto \color{blue}{{x}^{3} \cdot \left({x}^{2} \cdot \left(\frac{1}{120} + {x}^{2} \cdot \left(\frac{1}{362880} \cdot {x}^{2} - \frac{1}{5040}\right)\right) - \frac{1}{6}\right)} \]
      4. Step-by-step derivation
        1. Applied rewrites99.4%

          \[\leadsto \color{blue}{\mathsf{fma}\left(\mathsf{fma}\left(\mathsf{fma}\left(2.7557319223985893 \cdot 10^{-6}, x \cdot x, -0.0001984126984126984\right), x \cdot x, 0.008333333333333333\right), x \cdot x, -0.16666666666666666\right) \cdot {x}^{3}} \]
        2. Step-by-step derivation
          1. Applied rewrites99.4%

            \[\leadsto \mathsf{fma}\left(\mathsf{fma}\left(\mathsf{fma}\left(2.7557319223985893 \cdot 10^{-6}, x \cdot x, -0.0001984126984126984\right), x \cdot x, 0.008333333333333333\right), x \cdot x, -0.16666666666666666\right) \cdot \left(\left(x \cdot x\right) \cdot \color{blue}{x}\right) \]
          2. Step-by-step derivation
            1. Applied rewrites99.4%

              \[\leadsto \left(\left(\mathsf{fma}\left(\mathsf{fma}\left(\mathsf{fma}\left(2.7557319223985893 \cdot 10^{-6}, x \cdot x, -0.0001984126984126984\right), x \cdot x, 0.008333333333333333\right), x \cdot x, -0.16666666666666666\right) \cdot x\right) \cdot x\right) \cdot \color{blue}{x} \]
            2. Add Preprocessing

            Alternative 3: 98.6% accurate, 2.7× speedup?

            \[\begin{array}{l} \\ \mathsf{fma}\left(\mathsf{fma}\left(-0.0001984126984126984, x \cdot x, 0.008333333333333333\right), x \cdot x, -0.16666666666666666\right) \cdot \left(\left(x \cdot x\right) \cdot x\right) \end{array} \]
            (FPCore (x)
             :precision binary64
             (*
              (fma
               (fma -0.0001984126984126984 (* x x) 0.008333333333333333)
               (* x x)
               -0.16666666666666666)
              (* (* x x) x)))
            double code(double x) {
            	return fma(fma(-0.0001984126984126984, (x * x), 0.008333333333333333), (x * x), -0.16666666666666666) * ((x * x) * x);
            }
            
            function code(x)
            	return Float64(fma(fma(-0.0001984126984126984, Float64(x * x), 0.008333333333333333), Float64(x * x), -0.16666666666666666) * Float64(Float64(x * x) * x))
            end
            
            code[x_] := N[(N[(N[(-0.0001984126984126984 * N[(x * x), $MachinePrecision] + 0.008333333333333333), $MachinePrecision] * N[(x * x), $MachinePrecision] + -0.16666666666666666), $MachinePrecision] * N[(N[(x * x), $MachinePrecision] * x), $MachinePrecision]), $MachinePrecision]
            
            \begin{array}{l}
            
            \\
            \mathsf{fma}\left(\mathsf{fma}\left(-0.0001984126984126984, x \cdot x, 0.008333333333333333\right), x \cdot x, -0.16666666666666666\right) \cdot \left(\left(x \cdot x\right) \cdot x\right)
            \end{array}
            
            Derivation
            1. Initial program 68.2%

              \[\sin x - x \]
            2. Add Preprocessing
            3. Taylor expanded in x around 0

              \[\leadsto \color{blue}{{x}^{3} \cdot \left({x}^{2} \cdot \left(\frac{1}{120} + {x}^{2} \cdot \left(\frac{1}{362880} \cdot {x}^{2} - \frac{1}{5040}\right)\right) - \frac{1}{6}\right)} \]
            4. Step-by-step derivation
              1. Applied rewrites99.4%

                \[\leadsto \color{blue}{\mathsf{fma}\left(\mathsf{fma}\left(\mathsf{fma}\left(2.7557319223985893 \cdot 10^{-6}, x \cdot x, -0.0001984126984126984\right), x \cdot x, 0.008333333333333333\right), x \cdot x, -0.16666666666666666\right) \cdot {x}^{3}} \]
              2. Step-by-step derivation
                1. Applied rewrites99.4%

                  \[\leadsto \mathsf{fma}\left(\mathsf{fma}\left(\mathsf{fma}\left(2.7557319223985893 \cdot 10^{-6}, x \cdot x, -0.0001984126984126984\right), x \cdot x, 0.008333333333333333\right), x \cdot x, -0.16666666666666666\right) \cdot \left(\left(x \cdot x\right) \cdot \color{blue}{x}\right) \]
                2. Taylor expanded in x around 0

                  \[\leadsto \mathsf{fma}\left(\frac{1}{120} + \frac{-1}{5040} \cdot {x}^{2}, x \cdot x, \frac{-1}{6}\right) \cdot \left(\left(\color{blue}{x} \cdot x\right) \cdot x\right) \]
                3. Step-by-step derivation
                  1. Applied rewrites99.3%

                    \[\leadsto \mathsf{fma}\left(\mathsf{fma}\left(-0.0001984126984126984, x \cdot x, 0.008333333333333333\right), x \cdot x, -0.16666666666666666\right) \cdot \left(\left(\color{blue}{x} \cdot x\right) \cdot x\right) \]
                  2. Add Preprocessing

                  Alternative 4: 98.6% accurate, 2.7× speedup?

                  \[\begin{array}{l} \\ \left(\left(\mathsf{fma}\left(\mathsf{fma}\left(x \cdot x, -0.0001984126984126984, 0.008333333333333333\right), x \cdot x, -0.16666666666666666\right) \cdot x\right) \cdot x\right) \cdot x \end{array} \]
                  (FPCore (x)
                   :precision binary64
                   (*
                    (*
                     (*
                      (fma
                       (fma (* x x) -0.0001984126984126984 0.008333333333333333)
                       (* x x)
                       -0.16666666666666666)
                      x)
                     x)
                    x))
                  double code(double x) {
                  	return ((fma(fma((x * x), -0.0001984126984126984, 0.008333333333333333), (x * x), -0.16666666666666666) * x) * x) * x;
                  }
                  
                  function code(x)
                  	return Float64(Float64(Float64(fma(fma(Float64(x * x), -0.0001984126984126984, 0.008333333333333333), Float64(x * x), -0.16666666666666666) * x) * x) * x)
                  end
                  
                  code[x_] := N[(N[(N[(N[(N[(N[(x * x), $MachinePrecision] * -0.0001984126984126984 + 0.008333333333333333), $MachinePrecision] * N[(x * x), $MachinePrecision] + -0.16666666666666666), $MachinePrecision] * x), $MachinePrecision] * x), $MachinePrecision] * x), $MachinePrecision]
                  
                  \begin{array}{l}
                  
                  \\
                  \left(\left(\mathsf{fma}\left(\mathsf{fma}\left(x \cdot x, -0.0001984126984126984, 0.008333333333333333\right), x \cdot x, -0.16666666666666666\right) \cdot x\right) \cdot x\right) \cdot x
                  \end{array}
                  
                  Derivation
                  1. Initial program 68.2%

                    \[\sin x - x \]
                  2. Add Preprocessing
                  3. Taylor expanded in x around 0

                    \[\leadsto \color{blue}{{x}^{3} \cdot \left({x}^{2} \cdot \left(\frac{1}{120} + {x}^{2} \cdot \left(\frac{1}{362880} \cdot {x}^{2} - \frac{1}{5040}\right)\right) - \frac{1}{6}\right)} \]
                  4. Step-by-step derivation
                    1. Applied rewrites99.4%

                      \[\leadsto \color{blue}{\mathsf{fma}\left(\mathsf{fma}\left(\mathsf{fma}\left(2.7557319223985893 \cdot 10^{-6}, x \cdot x, -0.0001984126984126984\right), x \cdot x, 0.008333333333333333\right), x \cdot x, -0.16666666666666666\right) \cdot {x}^{3}} \]
                    2. Step-by-step derivation
                      1. Applied rewrites99.4%

                        \[\leadsto \mathsf{fma}\left(\mathsf{fma}\left(\mathsf{fma}\left(2.7557319223985893 \cdot 10^{-6}, x \cdot x, -0.0001984126984126984\right), x \cdot x, 0.008333333333333333\right), x \cdot x, -0.16666666666666666\right) \cdot \left(\left(x \cdot x\right) \cdot \color{blue}{x}\right) \]
                      2. Step-by-step derivation
                        1. Applied rewrites99.4%

                          \[\leadsto \left(\left(\mathsf{fma}\left(\mathsf{fma}\left(\mathsf{fma}\left(2.7557319223985893 \cdot 10^{-6}, x \cdot x, -0.0001984126984126984\right), x \cdot x, 0.008333333333333333\right), x \cdot x, -0.16666666666666666\right) \cdot x\right) \cdot x\right) \cdot \color{blue}{x} \]
                        2. Taylor expanded in x around 0

                          \[\leadsto \left(\left(x \cdot \left({x}^{2} \cdot \left(\frac{1}{120} + \frac{-1}{5040} \cdot {x}^{2}\right) - \frac{1}{6}\right)\right) \cdot x\right) \cdot x \]
                        3. Step-by-step derivation
                          1. Applied rewrites99.3%

                            \[\leadsto \left(\left(\mathsf{fma}\left(\mathsf{fma}\left(x \cdot x, -0.0001984126984126984, 0.008333333333333333\right), x \cdot x, -0.16666666666666666\right) \cdot x\right) \cdot x\right) \cdot x \]
                          2. Add Preprocessing

                          Alternative 5: 98.3% accurate, 3.9× speedup?

                          \[\begin{array}{l} \\ \left(\mathsf{fma}\left(0.008333333333333333, x \cdot x, -0.16666666666666666\right) \cdot x\right) \cdot \left(x \cdot x\right) \end{array} \]
                          (FPCore (x)
                           :precision binary64
                           (* (* (fma 0.008333333333333333 (* x x) -0.16666666666666666) x) (* x x)))
                          double code(double x) {
                          	return (fma(0.008333333333333333, (x * x), -0.16666666666666666) * x) * (x * x);
                          }
                          
                          function code(x)
                          	return Float64(Float64(fma(0.008333333333333333, Float64(x * x), -0.16666666666666666) * x) * Float64(x * x))
                          end
                          
                          code[x_] := N[(N[(N[(0.008333333333333333 * N[(x * x), $MachinePrecision] + -0.16666666666666666), $MachinePrecision] * x), $MachinePrecision] * N[(x * x), $MachinePrecision]), $MachinePrecision]
                          
                          \begin{array}{l}
                          
                          \\
                          \left(\mathsf{fma}\left(0.008333333333333333, x \cdot x, -0.16666666666666666\right) \cdot x\right) \cdot \left(x \cdot x\right)
                          \end{array}
                          
                          Derivation
                          1. Initial program 68.2%

                            \[\sin x - x \]
                          2. Add Preprocessing
                          3. Taylor expanded in x around 0

                            \[\leadsto \color{blue}{{x}^{3} \cdot \left(\frac{1}{120} \cdot {x}^{2} - \frac{1}{6}\right)} \]
                          4. Step-by-step derivation
                            1. Applied rewrites99.0%

                              \[\leadsto \color{blue}{\mathsf{fma}\left(x \cdot x, 0.008333333333333333, -0.16666666666666666\right) \cdot {x}^{3}} \]
                            2. Step-by-step derivation
                              1. Applied rewrites99.0%

                                \[\leadsto \left(\mathsf{fma}\left(0.008333333333333333, x \cdot x, -0.16666666666666666\right) \cdot x\right) \cdot \color{blue}{\left(x \cdot x\right)} \]
                              2. Add Preprocessing

                              Alternative 6: 97.9% accurate, 6.5× speedup?

                              \[\begin{array}{l} \\ \left(x \cdot x\right) \cdot \left(x \cdot -0.16666666666666666\right) \end{array} \]
                              (FPCore (x) :precision binary64 (* (* x x) (* x -0.16666666666666666)))
                              double code(double x) {
                              	return (x * x) * (x * -0.16666666666666666);
                              }
                              
                              module fmin_fmax_functions
                                  implicit none
                                  private
                                  public fmax
                                  public fmin
                              
                                  interface fmax
                                      module procedure fmax88
                                      module procedure fmax44
                                      module procedure fmax84
                                      module procedure fmax48
                                  end interface
                                  interface fmin
                                      module procedure fmin88
                                      module procedure fmin44
                                      module procedure fmin84
                                      module procedure fmin48
                                  end interface
                              contains
                                  real(8) function fmax88(x, y) result (res)
                                      real(8), intent (in) :: x
                                      real(8), intent (in) :: y
                                      res = merge(y, merge(x, max(x, y), y /= y), x /= x)
                                  end function
                                  real(4) function fmax44(x, y) result (res)
                                      real(4), intent (in) :: x
                                      real(4), intent (in) :: y
                                      res = merge(y, merge(x, max(x, y), y /= y), x /= x)
                                  end function
                                  real(8) function fmax84(x, y) result(res)
                                      real(8), intent (in) :: x
                                      real(4), intent (in) :: y
                                      res = merge(dble(y), merge(x, max(x, dble(y)), y /= y), x /= x)
                                  end function
                                  real(8) function fmax48(x, y) result(res)
                                      real(4), intent (in) :: x
                                      real(8), intent (in) :: y
                                      res = merge(y, merge(dble(x), max(dble(x), y), y /= y), x /= x)
                                  end function
                                  real(8) function fmin88(x, y) result (res)
                                      real(8), intent (in) :: x
                                      real(8), intent (in) :: y
                                      res = merge(y, merge(x, min(x, y), y /= y), x /= x)
                                  end function
                                  real(4) function fmin44(x, y) result (res)
                                      real(4), intent (in) :: x
                                      real(4), intent (in) :: y
                                      res = merge(y, merge(x, min(x, y), y /= y), x /= x)
                                  end function
                                  real(8) function fmin84(x, y) result(res)
                                      real(8), intent (in) :: x
                                      real(4), intent (in) :: y
                                      res = merge(dble(y), merge(x, min(x, dble(y)), y /= y), x /= x)
                                  end function
                                  real(8) function fmin48(x, y) result(res)
                                      real(4), intent (in) :: x
                                      real(8), intent (in) :: y
                                      res = merge(y, merge(dble(x), min(dble(x), y), y /= y), x /= x)
                                  end function
                              end module
                              
                              real(8) function code(x)
                              use fmin_fmax_functions
                                  real(8), intent (in) :: x
                                  code = (x * x) * (x * (-0.16666666666666666d0))
                              end function
                              
                              public static double code(double x) {
                              	return (x * x) * (x * -0.16666666666666666);
                              }
                              
                              def code(x):
                              	return (x * x) * (x * -0.16666666666666666)
                              
                              function code(x)
                              	return Float64(Float64(x * x) * Float64(x * -0.16666666666666666))
                              end
                              
                              function tmp = code(x)
                              	tmp = (x * x) * (x * -0.16666666666666666);
                              end
                              
                              code[x_] := N[(N[(x * x), $MachinePrecision] * N[(x * -0.16666666666666666), $MachinePrecision]), $MachinePrecision]
                              
                              \begin{array}{l}
                              
                              \\
                              \left(x \cdot x\right) \cdot \left(x \cdot -0.16666666666666666\right)
                              \end{array}
                              
                              Derivation
                              1. Initial program 68.2%

                                \[\sin x - x \]
                              2. Add Preprocessing
                              3. Taylor expanded in x around 0

                                \[\leadsto \color{blue}{\frac{-1}{6} \cdot {x}^{3}} \]
                              4. Step-by-step derivation
                                1. Applied rewrites98.5%

                                  \[\leadsto \color{blue}{{x}^{3} \cdot -0.16666666666666666} \]
                                2. Step-by-step derivation
                                  1. Applied rewrites98.5%

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

                                  Alternative 7: 97.9% accurate, 6.5× speedup?

                                  \[\begin{array}{l} \\ \left(-0.16666666666666666 \cdot \left(x \cdot x\right)\right) \cdot x \end{array} \]
                                  (FPCore (x) :precision binary64 (* (* -0.16666666666666666 (* x x)) x))
                                  double code(double x) {
                                  	return (-0.16666666666666666 * (x * x)) * x;
                                  }
                                  
                                  module fmin_fmax_functions
                                      implicit none
                                      private
                                      public fmax
                                      public fmin
                                  
                                      interface fmax
                                          module procedure fmax88
                                          module procedure fmax44
                                          module procedure fmax84
                                          module procedure fmax48
                                      end interface
                                      interface fmin
                                          module procedure fmin88
                                          module procedure fmin44
                                          module procedure fmin84
                                          module procedure fmin48
                                      end interface
                                  contains
                                      real(8) function fmax88(x, y) result (res)
                                          real(8), intent (in) :: x
                                          real(8), intent (in) :: y
                                          res = merge(y, merge(x, max(x, y), y /= y), x /= x)
                                      end function
                                      real(4) function fmax44(x, y) result (res)
                                          real(4), intent (in) :: x
                                          real(4), intent (in) :: y
                                          res = merge(y, merge(x, max(x, y), y /= y), x /= x)
                                      end function
                                      real(8) function fmax84(x, y) result(res)
                                          real(8), intent (in) :: x
                                          real(4), intent (in) :: y
                                          res = merge(dble(y), merge(x, max(x, dble(y)), y /= y), x /= x)
                                      end function
                                      real(8) function fmax48(x, y) result(res)
                                          real(4), intent (in) :: x
                                          real(8), intent (in) :: y
                                          res = merge(y, merge(dble(x), max(dble(x), y), y /= y), x /= x)
                                      end function
                                      real(8) function fmin88(x, y) result (res)
                                          real(8), intent (in) :: x
                                          real(8), intent (in) :: y
                                          res = merge(y, merge(x, min(x, y), y /= y), x /= x)
                                      end function
                                      real(4) function fmin44(x, y) result (res)
                                          real(4), intent (in) :: x
                                          real(4), intent (in) :: y
                                          res = merge(y, merge(x, min(x, y), y /= y), x /= x)
                                      end function
                                      real(8) function fmin84(x, y) result(res)
                                          real(8), intent (in) :: x
                                          real(4), intent (in) :: y
                                          res = merge(dble(y), merge(x, min(x, dble(y)), y /= y), x /= x)
                                      end function
                                      real(8) function fmin48(x, y) result(res)
                                          real(4), intent (in) :: x
                                          real(8), intent (in) :: y
                                          res = merge(y, merge(dble(x), min(dble(x), y), y /= y), x /= x)
                                      end function
                                  end module
                                  
                                  real(8) function code(x)
                                  use fmin_fmax_functions
                                      real(8), intent (in) :: x
                                      code = ((-0.16666666666666666d0) * (x * x)) * x
                                  end function
                                  
                                  public static double code(double x) {
                                  	return (-0.16666666666666666 * (x * x)) * x;
                                  }
                                  
                                  def code(x):
                                  	return (-0.16666666666666666 * (x * x)) * x
                                  
                                  function code(x)
                                  	return Float64(Float64(-0.16666666666666666 * Float64(x * x)) * x)
                                  end
                                  
                                  function tmp = code(x)
                                  	tmp = (-0.16666666666666666 * (x * x)) * x;
                                  end
                                  
                                  code[x_] := N[(N[(-0.16666666666666666 * N[(x * x), $MachinePrecision]), $MachinePrecision] * x), $MachinePrecision]
                                  
                                  \begin{array}{l}
                                  
                                  \\
                                  \left(-0.16666666666666666 \cdot \left(x \cdot x\right)\right) \cdot x
                                  \end{array}
                                  
                                  Derivation
                                  1. Initial program 68.2%

                                    \[\sin x - x \]
                                  2. Add Preprocessing
                                  3. Taylor expanded in x around 0

                                    \[\leadsto \color{blue}{\frac{-1}{6} \cdot {x}^{3}} \]
                                  4. Step-by-step derivation
                                    1. Applied rewrites98.5%

                                      \[\leadsto \color{blue}{{x}^{3} \cdot -0.16666666666666666} \]
                                    2. Step-by-step derivation
                                      1. Applied rewrites98.5%

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

                                      Alternative 8: 66.9% accurate, 26.0× speedup?

                                      \[\begin{array}{l} \\ x - x \end{array} \]
                                      (FPCore (x) :precision binary64 (- x x))
                                      double code(double x) {
                                      	return x - x;
                                      }
                                      
                                      module fmin_fmax_functions
                                          implicit none
                                          private
                                          public fmax
                                          public fmin
                                      
                                          interface fmax
                                              module procedure fmax88
                                              module procedure fmax44
                                              module procedure fmax84
                                              module procedure fmax48
                                          end interface
                                          interface fmin
                                              module procedure fmin88
                                              module procedure fmin44
                                              module procedure fmin84
                                              module procedure fmin48
                                          end interface
                                      contains
                                          real(8) function fmax88(x, y) result (res)
                                              real(8), intent (in) :: x
                                              real(8), intent (in) :: y
                                              res = merge(y, merge(x, max(x, y), y /= y), x /= x)
                                          end function
                                          real(4) function fmax44(x, y) result (res)
                                              real(4), intent (in) :: x
                                              real(4), intent (in) :: y
                                              res = merge(y, merge(x, max(x, y), y /= y), x /= x)
                                          end function
                                          real(8) function fmax84(x, y) result(res)
                                              real(8), intent (in) :: x
                                              real(4), intent (in) :: y
                                              res = merge(dble(y), merge(x, max(x, dble(y)), y /= y), x /= x)
                                          end function
                                          real(8) function fmax48(x, y) result(res)
                                              real(4), intent (in) :: x
                                              real(8), intent (in) :: y
                                              res = merge(y, merge(dble(x), max(dble(x), y), y /= y), x /= x)
                                          end function
                                          real(8) function fmin88(x, y) result (res)
                                              real(8), intent (in) :: x
                                              real(8), intent (in) :: y
                                              res = merge(y, merge(x, min(x, y), y /= y), x /= x)
                                          end function
                                          real(4) function fmin44(x, y) result (res)
                                              real(4), intent (in) :: x
                                              real(4), intent (in) :: y
                                              res = merge(y, merge(x, min(x, y), y /= y), x /= x)
                                          end function
                                          real(8) function fmin84(x, y) result(res)
                                              real(8), intent (in) :: x
                                              real(4), intent (in) :: y
                                              res = merge(dble(y), merge(x, min(x, dble(y)), y /= y), x /= x)
                                          end function
                                          real(8) function fmin48(x, y) result(res)
                                              real(4), intent (in) :: x
                                              real(8), intent (in) :: y
                                              res = merge(y, merge(dble(x), min(dble(x), y), y /= y), x /= x)
                                          end function
                                      end module
                                      
                                      real(8) function code(x)
                                      use fmin_fmax_functions
                                          real(8), intent (in) :: x
                                          code = x - x
                                      end function
                                      
                                      public static double code(double x) {
                                      	return x - x;
                                      }
                                      
                                      def code(x):
                                      	return x - x
                                      
                                      function code(x)
                                      	return Float64(x - x)
                                      end
                                      
                                      function tmp = code(x)
                                      	tmp = x - x;
                                      end
                                      
                                      code[x_] := N[(x - x), $MachinePrecision]
                                      
                                      \begin{array}{l}
                                      
                                      \\
                                      x - x
                                      \end{array}
                                      
                                      Derivation
                                      1. Initial program 68.2%

                                        \[\sin x - x \]
                                      2. Add Preprocessing
                                      3. Taylor expanded in x around 0

                                        \[\leadsto \color{blue}{x} - x \]
                                      4. Step-by-step derivation
                                        1. Applied rewrites66.4%

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

                                        Alternative 9: 6.5% accurate, 34.7× speedup?

                                        \[\begin{array}{l} \\ -x \end{array} \]
                                        (FPCore (x) :precision binary64 (- x))
                                        double code(double x) {
                                        	return -x;
                                        }
                                        
                                        module fmin_fmax_functions
                                            implicit none
                                            private
                                            public fmax
                                            public fmin
                                        
                                            interface fmax
                                                module procedure fmax88
                                                module procedure fmax44
                                                module procedure fmax84
                                                module procedure fmax48
                                            end interface
                                            interface fmin
                                                module procedure fmin88
                                                module procedure fmin44
                                                module procedure fmin84
                                                module procedure fmin48
                                            end interface
                                        contains
                                            real(8) function fmax88(x, y) result (res)
                                                real(8), intent (in) :: x
                                                real(8), intent (in) :: y
                                                res = merge(y, merge(x, max(x, y), y /= y), x /= x)
                                            end function
                                            real(4) function fmax44(x, y) result (res)
                                                real(4), intent (in) :: x
                                                real(4), intent (in) :: y
                                                res = merge(y, merge(x, max(x, y), y /= y), x /= x)
                                            end function
                                            real(8) function fmax84(x, y) result(res)
                                                real(8), intent (in) :: x
                                                real(4), intent (in) :: y
                                                res = merge(dble(y), merge(x, max(x, dble(y)), y /= y), x /= x)
                                            end function
                                            real(8) function fmax48(x, y) result(res)
                                                real(4), intent (in) :: x
                                                real(8), intent (in) :: y
                                                res = merge(y, merge(dble(x), max(dble(x), y), y /= y), x /= x)
                                            end function
                                            real(8) function fmin88(x, y) result (res)
                                                real(8), intent (in) :: x
                                                real(8), intent (in) :: y
                                                res = merge(y, merge(x, min(x, y), y /= y), x /= x)
                                            end function
                                            real(4) function fmin44(x, y) result (res)
                                                real(4), intent (in) :: x
                                                real(4), intent (in) :: y
                                                res = merge(y, merge(x, min(x, y), y /= y), x /= x)
                                            end function
                                            real(8) function fmin84(x, y) result(res)
                                                real(8), intent (in) :: x
                                                real(4), intent (in) :: y
                                                res = merge(dble(y), merge(x, min(x, dble(y)), y /= y), x /= x)
                                            end function
                                            real(8) function fmin48(x, y) result(res)
                                                real(4), intent (in) :: x
                                                real(8), intent (in) :: y
                                                res = merge(y, merge(dble(x), min(dble(x), y), y /= y), x /= x)
                                            end function
                                        end module
                                        
                                        real(8) function code(x)
                                        use fmin_fmax_functions
                                            real(8), intent (in) :: x
                                            code = -x
                                        end function
                                        
                                        public static double code(double x) {
                                        	return -x;
                                        }
                                        
                                        def code(x):
                                        	return -x
                                        
                                        function code(x)
                                        	return Float64(-x)
                                        end
                                        
                                        function tmp = code(x)
                                        	tmp = -x;
                                        end
                                        
                                        code[x_] := (-x)
                                        
                                        \begin{array}{l}
                                        
                                        \\
                                        -x
                                        \end{array}
                                        
                                        Derivation
                                        1. Initial program 68.2%

                                          \[\sin x - x \]
                                        2. Add Preprocessing
                                        3. Taylor expanded in x around inf

                                          \[\leadsto \color{blue}{-1 \cdot x} \]
                                        4. Step-by-step derivation
                                          1. Applied rewrites6.4%

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

                                          Developer Target 1: 99.8% accurate, 0.3× speedup?

                                          \[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;\left|x\right| < 0.07:\\ \;\;\;\;-\left(\left(\frac{{x}^{3}}{6} - \frac{{x}^{5}}{120}\right) + \frac{{x}^{7}}{5040}\right)\\ \mathbf{else}:\\ \;\;\;\;\sin x - x\\ \end{array} \end{array} \]
                                          (FPCore (x)
                                           :precision binary64
                                           (if (< (fabs x) 0.07)
                                             (- (+ (- (/ (pow x 3.0) 6.0) (/ (pow x 5.0) 120.0)) (/ (pow x 7.0) 5040.0)))
                                             (- (sin x) x)))
                                          double code(double x) {
                                          	double tmp;
                                          	if (fabs(x) < 0.07) {
                                          		tmp = -(((pow(x, 3.0) / 6.0) - (pow(x, 5.0) / 120.0)) + (pow(x, 7.0) / 5040.0));
                                          	} else {
                                          		tmp = sin(x) - x;
                                          	}
                                          	return tmp;
                                          }
                                          
                                          module fmin_fmax_functions
                                              implicit none
                                              private
                                              public fmax
                                              public fmin
                                          
                                              interface fmax
                                                  module procedure fmax88
                                                  module procedure fmax44
                                                  module procedure fmax84
                                                  module procedure fmax48
                                              end interface
                                              interface fmin
                                                  module procedure fmin88
                                                  module procedure fmin44
                                                  module procedure fmin84
                                                  module procedure fmin48
                                              end interface
                                          contains
                                              real(8) function fmax88(x, y) result (res)
                                                  real(8), intent (in) :: x
                                                  real(8), intent (in) :: y
                                                  res = merge(y, merge(x, max(x, y), y /= y), x /= x)
                                              end function
                                              real(4) function fmax44(x, y) result (res)
                                                  real(4), intent (in) :: x
                                                  real(4), intent (in) :: y
                                                  res = merge(y, merge(x, max(x, y), y /= y), x /= x)
                                              end function
                                              real(8) function fmax84(x, y) result(res)
                                                  real(8), intent (in) :: x
                                                  real(4), intent (in) :: y
                                                  res = merge(dble(y), merge(x, max(x, dble(y)), y /= y), x /= x)
                                              end function
                                              real(8) function fmax48(x, y) result(res)
                                                  real(4), intent (in) :: x
                                                  real(8), intent (in) :: y
                                                  res = merge(y, merge(dble(x), max(dble(x), y), y /= y), x /= x)
                                              end function
                                              real(8) function fmin88(x, y) result (res)
                                                  real(8), intent (in) :: x
                                                  real(8), intent (in) :: y
                                                  res = merge(y, merge(x, min(x, y), y /= y), x /= x)
                                              end function
                                              real(4) function fmin44(x, y) result (res)
                                                  real(4), intent (in) :: x
                                                  real(4), intent (in) :: y
                                                  res = merge(y, merge(x, min(x, y), y /= y), x /= x)
                                              end function
                                              real(8) function fmin84(x, y) result(res)
                                                  real(8), intent (in) :: x
                                                  real(4), intent (in) :: y
                                                  res = merge(dble(y), merge(x, min(x, dble(y)), y /= y), x /= x)
                                              end function
                                              real(8) function fmin48(x, y) result(res)
                                                  real(4), intent (in) :: x
                                                  real(8), intent (in) :: y
                                                  res = merge(y, merge(dble(x), min(dble(x), y), y /= y), x /= x)
                                              end function
                                          end module
                                          
                                          real(8) function code(x)
                                          use fmin_fmax_functions
                                              real(8), intent (in) :: x
                                              real(8) :: tmp
                                              if (abs(x) < 0.07d0) then
                                                  tmp = -((((x ** 3.0d0) / 6.0d0) - ((x ** 5.0d0) / 120.0d0)) + ((x ** 7.0d0) / 5040.0d0))
                                              else
                                                  tmp = sin(x) - x
                                              end if
                                              code = tmp
                                          end function
                                          
                                          public static double code(double x) {
                                          	double tmp;
                                          	if (Math.abs(x) < 0.07) {
                                          		tmp = -(((Math.pow(x, 3.0) / 6.0) - (Math.pow(x, 5.0) / 120.0)) + (Math.pow(x, 7.0) / 5040.0));
                                          	} else {
                                          		tmp = Math.sin(x) - x;
                                          	}
                                          	return tmp;
                                          }
                                          
                                          def code(x):
                                          	tmp = 0
                                          	if math.fabs(x) < 0.07:
                                          		tmp = -(((math.pow(x, 3.0) / 6.0) - (math.pow(x, 5.0) / 120.0)) + (math.pow(x, 7.0) / 5040.0))
                                          	else:
                                          		tmp = math.sin(x) - x
                                          	return tmp
                                          
                                          function code(x)
                                          	tmp = 0.0
                                          	if (abs(x) < 0.07)
                                          		tmp = Float64(-Float64(Float64(Float64((x ^ 3.0) / 6.0) - Float64((x ^ 5.0) / 120.0)) + Float64((x ^ 7.0) / 5040.0)));
                                          	else
                                          		tmp = Float64(sin(x) - x);
                                          	end
                                          	return tmp
                                          end
                                          
                                          function tmp_2 = code(x)
                                          	tmp = 0.0;
                                          	if (abs(x) < 0.07)
                                          		tmp = -((((x ^ 3.0) / 6.0) - ((x ^ 5.0) / 120.0)) + ((x ^ 7.0) / 5040.0));
                                          	else
                                          		tmp = sin(x) - x;
                                          	end
                                          	tmp_2 = tmp;
                                          end
                                          
                                          code[x_] := If[Less[N[Abs[x], $MachinePrecision], 0.07], (-N[(N[(N[(N[Power[x, 3.0], $MachinePrecision] / 6.0), $MachinePrecision] - N[(N[Power[x, 5.0], $MachinePrecision] / 120.0), $MachinePrecision]), $MachinePrecision] + N[(N[Power[x, 7.0], $MachinePrecision] / 5040.0), $MachinePrecision]), $MachinePrecision]), N[(N[Sin[x], $MachinePrecision] - x), $MachinePrecision]]
                                          
                                          \begin{array}{l}
                                          
                                          \\
                                          \begin{array}{l}
                                          \mathbf{if}\;\left|x\right| < 0.07:\\
                                          \;\;\;\;-\left(\left(\frac{{x}^{3}}{6} - \frac{{x}^{5}}{120}\right) + \frac{{x}^{7}}{5040}\right)\\
                                          
                                          \mathbf{else}:\\
                                          \;\;\;\;\sin x - x\\
                                          
                                          
                                          \end{array}
                                          \end{array}
                                          

                                          Reproduce

                                          ?
                                          herbie shell --seed 2025026 
                                          (FPCore (x)
                                            :name "bug500 (missed optimization)"
                                            :precision binary64
                                            :pre (and (< -1000.0 x) (< x 1000.0))
                                          
                                            :alt
                                            (! :herbie-platform default (if (< (fabs x) 7/100) (- (+ (- (/ (pow x 3) 6) (/ (pow x 5) 120)) (/ (pow x 7) 5040))) (- (sin x) x)))
                                          
                                            (- (sin x) x))