bug500 (missed optimization)

Percentage Accurate: 69.6% → 98.7%
Time: 4.7s
Alternatives: 8
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 8 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: 69.6% 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: 98.7% accurate, 0.8× speedup?

\[\begin{array}{l} \\ \mathsf{fma}\left(\mathsf{fma}\left(-0.0001984126984126984, x \cdot x, 0.008333333333333333\right), x \cdot x, -0.16666666666666666\right) \cdot {x}^{3} \end{array} \]
(FPCore (x)
 :precision binary64
 (*
  (fma
   (fma -0.0001984126984126984 (* x x) 0.008333333333333333)
   (* x x)
   -0.16666666666666666)
  (pow x 3.0)))
double code(double x) {
	return fma(fma(-0.0001984126984126984, (x * x), 0.008333333333333333), (x * x), -0.16666666666666666) * pow(x, 3.0);
}
function code(x)
	return Float64(fma(fma(-0.0001984126984126984, Float64(x * x), 0.008333333333333333), Float64(x * x), -0.16666666666666666) * (x ^ 3.0))
end
code[x_] := N[(N[(N[(-0.0001984126984126984 * N[(x * x), $MachinePrecision] + 0.008333333333333333), $MachinePrecision] * N[(x * x), $MachinePrecision] + -0.16666666666666666), $MachinePrecision] * N[Power[x, 3.0], $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 {x}^{3}
\end{array}
Derivation
  1. Initial program 68.2%

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

    \[\leadsto \color{blue}{{x}^{3} \cdot \left({x}^{2} \cdot \left(\frac{1}{120} + \frac{-1}{5040} \cdot {x}^{2}\right) - \frac{1}{6}\right)} \]
  4. Step-by-step derivation
    1. Applied rewrites97.2%

      \[\leadsto \color{blue}{\mathsf{fma}\left(\mathsf{fma}\left(-0.0001984126984126984, x \cdot x, 0.008333333333333333\right), x \cdot x, -0.16666666666666666\right) \cdot {x}^{3}} \]
    2. Add Preprocessing

    Alternative 2: 98.6% accurate, 2.4× speedup?

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

      \[\leadsto \color{blue}{{x}^{3} \cdot \left({x}^{2} \cdot \left(\frac{1}{120} + \frac{-1}{5040} \cdot {x}^{2}\right) - \frac{1}{6}\right)} \]
    4. Step-by-step derivation
      1. Applied rewrites97.2%

        \[\leadsto \color{blue}{\mathsf{fma}\left(\mathsf{fma}\left(-0.0001984126984126984, x \cdot x, 0.008333333333333333\right), x \cdot x, -0.16666666666666666\right) \cdot {x}^{3}} \]
      2. Step-by-step derivation
        1. Applied rewrites97.2%

          \[\leadsto \left(\mathsf{fma}\left(\mathsf{fma}\left(x \cdot x, -0.0001984126984126984, 0.008333333333333333\right), x \cdot x, -0.16666666666666666\right) \cdot x\right) \cdot \color{blue}{\left(x \cdot x\right)} \]
        2. Step-by-step derivation
          1. Applied rewrites97.2%

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

          Alternative 3: 98.6% accurate, 2.7× speedup?

          \[\begin{array}{l} \\ \left(\mathsf{fma}\left(\mathsf{fma}\left(x \cdot x, -0.0001984126984126984, 0.008333333333333333\right), x \cdot x, -0.16666666666666666\right) \cdot x\right) \cdot \left(x \cdot x\right) \end{array} \]
          (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(fma(fma(Float64(x * x), -0.0001984126984126984, 0.008333333333333333), Float64(x * x), -0.16666666666666666) * x) * Float64(x * x))
          end
          
          code[x_] := N[(N[(N[(N[(N[(x * x), $MachinePrecision] * -0.0001984126984126984 + 0.008333333333333333), $MachinePrecision] * N[(x * x), $MachinePrecision] + -0.16666666666666666), $MachinePrecision] * x), $MachinePrecision] * N[(x * x), $MachinePrecision]), $MachinePrecision]
          
          \begin{array}{l}
          
          \\
          \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 \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

            \[\leadsto \color{blue}{{x}^{3} \cdot \left({x}^{2} \cdot \left(\frac{1}{120} + \frac{-1}{5040} \cdot {x}^{2}\right) - \frac{1}{6}\right)} \]
          4. Step-by-step derivation
            1. Applied rewrites97.2%

              \[\leadsto \color{blue}{\mathsf{fma}\left(\mathsf{fma}\left(-0.0001984126984126984, x \cdot x, 0.008333333333333333\right), x \cdot x, -0.16666666666666666\right) \cdot {x}^{3}} \]
            2. Step-by-step derivation
              1. Applied rewrites97.2%

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

              Alternative 4: 98.3% accurate, 3.9× speedup?

              \[\begin{array}{l} \\ \left(\left(\mathsf{fma}\left(0.008333333333333333, x \cdot x, -0.16666666666666666\right) \cdot x\right) \cdot x\right) \cdot x \end{array} \]
              (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(Float64(fma(0.008333333333333333, Float64(x * x), -0.16666666666666666) * x) * x) * x)
              end
              
              code[x_] := N[(N[(N[(N[(0.008333333333333333 * N[(x * x), $MachinePrecision] + -0.16666666666666666), $MachinePrecision] * x), $MachinePrecision] * x), $MachinePrecision] * x), $MachinePrecision]
              
              \begin{array}{l}
              
              \\
              \left(\left(\mathsf{fma}\left(0.008333333333333333, 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

                \[\leadsto \color{blue}{{x}^{3} \cdot \left(\frac{1}{120} \cdot {x}^{2} - \frac{1}{6}\right)} \]
              4. Step-by-step derivation
                1. Applied rewrites96.7%

                  \[\leadsto \color{blue}{\mathsf{fma}\left(x \cdot x, 0.008333333333333333, -0.16666666666666666\right) \cdot {x}^{3}} \]
                2. Step-by-step derivation
                  1. Applied rewrites96.7%

                    \[\leadsto \mathsf{fma}\left(x \cdot x, 0.008333333333333333, -0.16666666666666666\right) \cdot \left(\left(x \cdot x\right) \cdot \color{blue}{x}\right) \]
                  2. Step-by-step derivation
                    1. Applied rewrites96.7%

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

                    Alternative 5: 97.8% accurate, 6.5× speedup?

                    \[\begin{array}{l} \\ \left(\left(-0.16666666666666666 \cdot x\right) \cdot x\right) \cdot x \end{array} \]
                    (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(Float64(-0.16666666666666666 * x) * x) * x)
                    end
                    
                    function tmp = code(x)
                    	tmp = ((-0.16666666666666666 * x) * x) * x;
                    end
                    
                    code[x_] := N[(N[(N[(-0.16666666666666666 * x), $MachinePrecision] * x), $MachinePrecision] * x), $MachinePrecision]
                    
                    \begin{array}{l}
                    
                    \\
                    \left(\left(-0.16666666666666666 \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

                      \[\leadsto \color{blue}{\frac{-1}{6} \cdot {x}^{3}} \]
                    4. Step-by-step derivation
                      1. Applied rewrites96.2%

                        \[\leadsto \color{blue}{{x}^{3} \cdot -0.16666666666666666} \]
                      2. Step-by-step derivation
                        1. Applied rewrites96.2%

                          \[\leadsto \left(-0.16666666666666666 \cdot \left(x \cdot x\right)\right) \cdot \color{blue}{x} \]
                        2. Step-by-step derivation
                          1. Applied rewrites96.3%

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

                          Alternative 6: 97.8% 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 rewrites96.2%

                              \[\leadsto \color{blue}{{x}^{3} \cdot -0.16666666666666666} \]
                            2. Step-by-step derivation
                              1. Applied rewrites96.2%

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

                              Alternative 7: 66.8% 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 rewrites63.5%

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

                                Alternative 8: 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 rewrites6.9%

                                    \[\leadsto \color{blue}{-x} \]
                                  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 2025019 
                                  (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))