Data.Number.Erf:$dmerfcx from erf-2.0.0.0

Percentage Accurate: 100.0% → 100.0%
Time: 4.3s
Alternatives: 8
Speedup: 1.0×

Specification

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

\\
x \cdot e^{y \cdot y}
\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: 100.0% accurate, 1.0× speedup?

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

\\
x \cdot e^{y \cdot y}
\end{array}

Alternative 1: 100.0% accurate, 1.0× speedup?

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

\\
x \cdot e^{y \cdot y}
\end{array}
Derivation
  1. Initial program 100.0%

    \[x \cdot e^{y \cdot y} \]
  2. Add Preprocessing
  3. Add Preprocessing

Alternative 2: 91.2% accurate, 3.7× speedup?

\[\begin{array}{l} \\ \left(-x\right) \cdot \mathsf{fma}\left(\mathsf{fma}\left(-0.5, y \cdot y, -1\right), y \cdot y, -1\right) \end{array} \]
(FPCore (x y)
 :precision binary64
 (* (- x) (fma (fma -0.5 (* y y) -1.0) (* y y) -1.0)))
double code(double x, double y) {
	return -x * fma(fma(-0.5, (y * y), -1.0), (y * y), -1.0);
}
function code(x, y)
	return Float64(Float64(-x) * fma(fma(-0.5, Float64(y * y), -1.0), Float64(y * y), -1.0))
end
code[x_, y_] := N[((-x) * N[(N[(-0.5 * N[(y * y), $MachinePrecision] + -1.0), $MachinePrecision] * N[(y * y), $MachinePrecision] + -1.0), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}

\\
\left(-x\right) \cdot \mathsf{fma}\left(\mathsf{fma}\left(-0.5, y \cdot y, -1\right), y \cdot y, -1\right)
\end{array}
Derivation
  1. Initial program 100.0%

    \[x \cdot e^{y \cdot y} \]
  2. Add Preprocessing
  3. Taylor expanded in y around 0

    \[\leadsto \color{blue}{x} \]
  4. Step-by-step derivation
    1. Applied rewrites50.5%

      \[\leadsto \color{blue}{x} \]
    2. Taylor expanded in y around 0

      \[\leadsto \color{blue}{x + {y}^{2} \cdot \left(x + \frac{1}{2} \cdot \left(x \cdot {y}^{2}\right)\right)} \]
    3. Step-by-step derivation
      1. Applied rewrites88.0%

        \[\leadsto \color{blue}{\mathsf{fma}\left(\mathsf{fma}\left(0.5, \left(y \cdot y\right) \cdot x, x\right), y \cdot y, x\right)} \]
      2. Taylor expanded in x around -inf

        \[\leadsto -1 \cdot \color{blue}{\left(x \cdot \left({y}^{2} \cdot \left(\frac{-1}{2} \cdot {y}^{2} - 1\right) - 1\right)\right)} \]
      3. Applied rewrites89.5%

        \[\leadsto \left(-x\right) \cdot \color{blue}{\mathsf{fma}\left(\mathsf{fma}\left(-0.5, y \cdot y, -1\right), y \cdot y, -1\right)} \]
      4. Add Preprocessing

      Alternative 3: 88.4% accurate, 4.0× speedup?

      \[\begin{array}{l} \\ \mathsf{fma}\left(\mathsf{fma}\left(x \cdot \left(y \cdot y\right), 0.5, x\right) \cdot y, y, x\right) \end{array} \]
      (FPCore (x y) :precision binary64 (fma (* (fma (* x (* y y)) 0.5 x) y) y x))
      double code(double x, double y) {
      	return fma((fma((x * (y * y)), 0.5, x) * y), y, x);
      }
      
      function code(x, y)
      	return fma(Float64(fma(Float64(x * Float64(y * y)), 0.5, x) * y), y, x)
      end
      
      code[x_, y_] := N[(N[(N[(N[(x * N[(y * y), $MachinePrecision]), $MachinePrecision] * 0.5 + x), $MachinePrecision] * y), $MachinePrecision] * y + x), $MachinePrecision]
      
      \begin{array}{l}
      
      \\
      \mathsf{fma}\left(\mathsf{fma}\left(x \cdot \left(y \cdot y\right), 0.5, x\right) \cdot y, y, x\right)
      \end{array}
      
      Derivation
      1. Initial program 100.0%

        \[x \cdot e^{y \cdot y} \]
      2. Add Preprocessing
      3. Taylor expanded in y around 0

        \[\leadsto \color{blue}{x} \]
      4. Step-by-step derivation
        1. Applied rewrites50.5%

          \[\leadsto \color{blue}{x} \]
        2. Taylor expanded in y around 0

          \[\leadsto \color{blue}{x + {y}^{2} \cdot \left(x + \frac{1}{2} \cdot \left(x \cdot {y}^{2}\right)\right)} \]
        3. Step-by-step derivation
          1. Applied rewrites88.0%

            \[\leadsto \color{blue}{\mathsf{fma}\left(\mathsf{fma}\left(0.5, \left(y \cdot y\right) \cdot x, x\right), y \cdot y, x\right)} \]
          2. Step-by-step derivation
            1. Applied rewrites88.0%

              \[\leadsto \mathsf{fma}\left(\mathsf{fma}\left(x \cdot \left(y \cdot y\right), 0.5, x\right) \cdot y, \color{blue}{y}, x\right) \]
            2. Add Preprocessing

            Alternative 4: 88.0% accurate, 4.1× speedup?

            \[\begin{array}{l} \\ \mathsf{fma}\left(\left(\left(y \cdot y\right) \cdot x\right) \cdot 0.5, y \cdot y, x\right) \end{array} \]
            (FPCore (x y) :precision binary64 (fma (* (* (* y y) x) 0.5) (* y y) x))
            double code(double x, double y) {
            	return fma((((y * y) * x) * 0.5), (y * y), x);
            }
            
            function code(x, y)
            	return fma(Float64(Float64(Float64(y * y) * x) * 0.5), Float64(y * y), x)
            end
            
            code[x_, y_] := N[(N[(N[(N[(y * y), $MachinePrecision] * x), $MachinePrecision] * 0.5), $MachinePrecision] * N[(y * y), $MachinePrecision] + x), $MachinePrecision]
            
            \begin{array}{l}
            
            \\
            \mathsf{fma}\left(\left(\left(y \cdot y\right) \cdot x\right) \cdot 0.5, y \cdot y, x\right)
            \end{array}
            
            Derivation
            1. Initial program 100.0%

              \[x \cdot e^{y \cdot y} \]
            2. Add Preprocessing
            3. Taylor expanded in y around 0

              \[\leadsto \color{blue}{x} \]
            4. Step-by-step derivation
              1. Applied rewrites50.5%

                \[\leadsto \color{blue}{x} \]
              2. Taylor expanded in y around 0

                \[\leadsto \color{blue}{x + {y}^{2} \cdot \left(x + \frac{1}{2} \cdot \left(x \cdot {y}^{2}\right)\right)} \]
              3. Step-by-step derivation
                1. Applied rewrites88.0%

                  \[\leadsto \color{blue}{\mathsf{fma}\left(\mathsf{fma}\left(0.5, \left(y \cdot y\right) \cdot x, x\right), y \cdot y, x\right)} \]
                2. Taylor expanded in y around inf

                  \[\leadsto \mathsf{fma}\left(\frac{1}{2} \cdot \left(x \cdot {y}^{2}\right), \color{blue}{y} \cdot y, x\right) \]
                3. Step-by-step derivation
                  1. Applied rewrites87.7%

                    \[\leadsto \mathsf{fma}\left(\left(\left(y \cdot y\right) \cdot x\right) \cdot 0.5, \color{blue}{y} \cdot y, x\right) \]
                  2. Add Preprocessing

                  Alternative 5: 79.2% accurate, 6.2× speedup?

                  \[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;y \leq 5 \cdot 10^{+29}:\\ \;\;\;\;\mathsf{fma}\left(y \cdot x, y, x\right)\\ \mathbf{else}:\\ \;\;\;\;x \cdot \left(y \cdot y\right)\\ \end{array} \end{array} \]
                  (FPCore (x y)
                   :precision binary64
                   (if (<= y 5e+29) (fma (* y x) y x) (* x (* y y))))
                  double code(double x, double y) {
                  	double tmp;
                  	if (y <= 5e+29) {
                  		tmp = fma((y * x), y, x);
                  	} else {
                  		tmp = x * (y * y);
                  	}
                  	return tmp;
                  }
                  
                  function code(x, y)
                  	tmp = 0.0
                  	if (y <= 5e+29)
                  		tmp = fma(Float64(y * x), y, x);
                  	else
                  		tmp = Float64(x * Float64(y * y));
                  	end
                  	return tmp
                  end
                  
                  code[x_, y_] := If[LessEqual[y, 5e+29], N[(N[(y * x), $MachinePrecision] * y + x), $MachinePrecision], N[(x * N[(y * y), $MachinePrecision]), $MachinePrecision]]
                  
                  \begin{array}{l}
                  
                  \\
                  \begin{array}{l}
                  \mathbf{if}\;y \leq 5 \cdot 10^{+29}:\\
                  \;\;\;\;\mathsf{fma}\left(y \cdot x, y, x\right)\\
                  
                  \mathbf{else}:\\
                  \;\;\;\;x \cdot \left(y \cdot y\right)\\
                  
                  
                  \end{array}
                  \end{array}
                  
                  Derivation
                  1. Split input into 2 regimes
                  2. if y < 5.0000000000000001e29

                    1. Initial program 100.0%

                      \[x \cdot e^{y \cdot y} \]
                    2. Add Preprocessing
                    3. Taylor expanded in y around 0

                      \[\leadsto \color{blue}{x} \]
                    4. Step-by-step derivation
                      1. Applied rewrites65.6%

                        \[\leadsto \color{blue}{x} \]
                      2. Taylor expanded in y around 0

                        \[\leadsto \color{blue}{x + {y}^{2} \cdot \left(x + \frac{1}{2} \cdot \left(x \cdot {y}^{2}\right)\right)} \]
                      3. Step-by-step derivation
                        1. Applied rewrites91.6%

                          \[\leadsto \color{blue}{\mathsf{fma}\left(\mathsf{fma}\left(0.5, \left(y \cdot y\right) \cdot x, x\right), y \cdot y, x\right)} \]
                        2. Taylor expanded in x around -inf

                          \[\leadsto -1 \cdot \color{blue}{\left(x \cdot \left({y}^{2} \cdot \left(\frac{-1}{2} \cdot {y}^{2} - 1\right) - 1\right)\right)} \]
                        3. Applied rewrites92.6%

                          \[\leadsto \left(-x\right) \cdot \color{blue}{\mathsf{fma}\left(\mathsf{fma}\left(-0.5, y \cdot y, -1\right), y \cdot y, -1\right)} \]
                        4. Taylor expanded in y around 0

                          \[\leadsto \color{blue}{x + x \cdot {y}^{2}} \]
                        5. Step-by-step derivation
                          1. Applied rewrites83.9%

                            \[\leadsto \color{blue}{\mathsf{fma}\left(y \cdot x, y, x\right)} \]

                          if 5.0000000000000001e29 < y

                          1. Initial program 100.0%

                            \[x \cdot e^{y \cdot y} \]
                          2. Add Preprocessing
                          3. Taylor expanded in y around 0

                            \[\leadsto x \cdot \color{blue}{\left(1 + {y}^{2}\right)} \]
                          4. Step-by-step derivation
                            1. Applied rewrites61.5%

                              \[\leadsto x \cdot \color{blue}{\mathsf{fma}\left(y, y, 1\right)} \]
                            2. Taylor expanded in y around inf

                              \[\leadsto x \cdot {y}^{\color{blue}{2}} \]
                            3. Step-by-step derivation
                              1. Applied rewrites61.5%

                                \[\leadsto x \cdot \left(y \cdot \color{blue}{y}\right) \]
                            4. Recombined 2 regimes into one program.
                            5. Add Preprocessing

                            Alternative 6: 66.3% accurate, 6.5× speedup?

                            \[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;y \leq 1:\\ \;\;\;\;x\\ \mathbf{else}:\\ \;\;\;\;x \cdot \left(y \cdot y\right)\\ \end{array} \end{array} \]
                            (FPCore (x y) :precision binary64 (if (<= y 1.0) x (* x (* y y))))
                            double code(double x, double y) {
                            	double tmp;
                            	if (y <= 1.0) {
                            		tmp = x;
                            	} else {
                            		tmp = x * (y * y);
                            	}
                            	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, y)
                            use fmin_fmax_functions
                                real(8), intent (in) :: x
                                real(8), intent (in) :: y
                                real(8) :: tmp
                                if (y <= 1.0d0) then
                                    tmp = x
                                else
                                    tmp = x * (y * y)
                                end if
                                code = tmp
                            end function
                            
                            public static double code(double x, double y) {
                            	double tmp;
                            	if (y <= 1.0) {
                            		tmp = x;
                            	} else {
                            		tmp = x * (y * y);
                            	}
                            	return tmp;
                            }
                            
                            def code(x, y):
                            	tmp = 0
                            	if y <= 1.0:
                            		tmp = x
                            	else:
                            		tmp = x * (y * y)
                            	return tmp
                            
                            function code(x, y)
                            	tmp = 0.0
                            	if (y <= 1.0)
                            		tmp = x;
                            	else
                            		tmp = Float64(x * Float64(y * y));
                            	end
                            	return tmp
                            end
                            
                            function tmp_2 = code(x, y)
                            	tmp = 0.0;
                            	if (y <= 1.0)
                            		tmp = x;
                            	else
                            		tmp = x * (y * y);
                            	end
                            	tmp_2 = tmp;
                            end
                            
                            code[x_, y_] := If[LessEqual[y, 1.0], x, N[(x * N[(y * y), $MachinePrecision]), $MachinePrecision]]
                            
                            \begin{array}{l}
                            
                            \\
                            \begin{array}{l}
                            \mathbf{if}\;y \leq 1:\\
                            \;\;\;\;x\\
                            
                            \mathbf{else}:\\
                            \;\;\;\;x \cdot \left(y \cdot y\right)\\
                            
                            
                            \end{array}
                            \end{array}
                            
                            Derivation
                            1. Split input into 2 regimes
                            2. if y < 1

                              1. Initial program 100.0%

                                \[x \cdot e^{y \cdot y} \]
                              2. Add Preprocessing
                              3. Taylor expanded in y around 0

                                \[\leadsto \color{blue}{x} \]
                              4. Step-by-step derivation
                                1. Applied rewrites68.9%

                                  \[\leadsto \color{blue}{x} \]

                                if 1 < y

                                1. Initial program 100.0%

                                  \[x \cdot e^{y \cdot y} \]
                                2. Add Preprocessing
                                3. Taylor expanded in y around 0

                                  \[\leadsto x \cdot \color{blue}{\left(1 + {y}^{2}\right)} \]
                                4. Step-by-step derivation
                                  1. Applied rewrites53.7%

                                    \[\leadsto x \cdot \color{blue}{\mathsf{fma}\left(y, y, 1\right)} \]
                                  2. Taylor expanded in y around inf

                                    \[\leadsto x \cdot {y}^{\color{blue}{2}} \]
                                  3. Step-by-step derivation
                                    1. Applied rewrites53.7%

                                      \[\leadsto x \cdot \left(y \cdot \color{blue}{y}\right) \]
                                  4. Recombined 2 regimes into one program.
                                  5. Add Preprocessing

                                  Alternative 7: 82.3% accurate, 9.3× speedup?

                                  \[\begin{array}{l} \\ x \cdot \mathsf{fma}\left(y, y, 1\right) \end{array} \]
                                  (FPCore (x y) :precision binary64 (* x (fma y y 1.0)))
                                  double code(double x, double y) {
                                  	return x * fma(y, y, 1.0);
                                  }
                                  
                                  function code(x, y)
                                  	return Float64(x * fma(y, y, 1.0))
                                  end
                                  
                                  code[x_, y_] := N[(x * N[(y * y + 1.0), $MachinePrecision]), $MachinePrecision]
                                  
                                  \begin{array}{l}
                                  
                                  \\
                                  x \cdot \mathsf{fma}\left(y, y, 1\right)
                                  \end{array}
                                  
                                  Derivation
                                  1. Initial program 100.0%

                                    \[x \cdot e^{y \cdot y} \]
                                  2. Add Preprocessing
                                  3. Taylor expanded in y around 0

                                    \[\leadsto x \cdot \color{blue}{\left(1 + {y}^{2}\right)} \]
                                  4. Step-by-step derivation
                                    1. Applied rewrites79.9%

                                      \[\leadsto x \cdot \color{blue}{\mathsf{fma}\left(y, y, 1\right)} \]
                                    2. Add Preprocessing

                                    Alternative 8: 51.4% accurate, 111.0× speedup?

                                    \[\begin{array}{l} \\ x \end{array} \]
                                    (FPCore (x y) :precision binary64 x)
                                    double code(double x, double y) {
                                    	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, y)
                                    use fmin_fmax_functions
                                        real(8), intent (in) :: x
                                        real(8), intent (in) :: y
                                        code = x
                                    end function
                                    
                                    public static double code(double x, double y) {
                                    	return x;
                                    }
                                    
                                    def code(x, y):
                                    	return x
                                    
                                    function code(x, y)
                                    	return x
                                    end
                                    
                                    function tmp = code(x, y)
                                    	tmp = x;
                                    end
                                    
                                    code[x_, y_] := x
                                    
                                    \begin{array}{l}
                                    
                                    \\
                                    x
                                    \end{array}
                                    
                                    Derivation
                                    1. Initial program 100.0%

                                      \[x \cdot e^{y \cdot y} \]
                                    2. Add Preprocessing
                                    3. Taylor expanded in y around 0

                                      \[\leadsto \color{blue}{x} \]
                                    4. Step-by-step derivation
                                      1. Applied rewrites50.5%

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

                                      Developer Target 1: 100.0% accurate, 0.5× speedup?

                                      \[\begin{array}{l} \\ x \cdot {\left(e^{y}\right)}^{y} \end{array} \]
                                      (FPCore (x y) :precision binary64 (* x (pow (exp y) y)))
                                      double code(double x, double y) {
                                      	return x * pow(exp(y), y);
                                      }
                                      
                                      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, y)
                                      use fmin_fmax_functions
                                          real(8), intent (in) :: x
                                          real(8), intent (in) :: y
                                          code = x * (exp(y) ** y)
                                      end function
                                      
                                      public static double code(double x, double y) {
                                      	return x * Math.pow(Math.exp(y), y);
                                      }
                                      
                                      def code(x, y):
                                      	return x * math.pow(math.exp(y), y)
                                      
                                      function code(x, y)
                                      	return Float64(x * (exp(y) ^ y))
                                      end
                                      
                                      function tmp = code(x, y)
                                      	tmp = x * (exp(y) ^ y);
                                      end
                                      
                                      code[x_, y_] := N[(x * N[Power[N[Exp[y], $MachinePrecision], y], $MachinePrecision]), $MachinePrecision]
                                      
                                      \begin{array}{l}
                                      
                                      \\
                                      x \cdot {\left(e^{y}\right)}^{y}
                                      \end{array}
                                      

                                      Reproduce

                                      ?
                                      herbie shell --seed 2025056 
                                      (FPCore (x y)
                                        :name "Data.Number.Erf:$dmerfcx from erf-2.0.0.0"
                                        :precision binary64
                                      
                                        :alt
                                        (! :herbie-platform default (* x (pow (exp y) y)))
                                      
                                        (* x (exp (* y y))))