bug366 (missed optimization)

Percentage Accurate: 45.6% → 98.4%
Time: 2.1s
Alternatives: 3
Speedup: 32.0×

Specification

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

\\
\sqrt{x \cdot x + \left(y \cdot y + z \cdot z\right)}
\end{array}

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 3 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: 45.6% accurate, 1.0× speedup?

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

\\
\sqrt{x \cdot x + \left(y \cdot y + z \cdot z\right)}
\end{array}

Alternative 1: 98.4% accurate, 32.0× speedup?

\[\begin{array}{l} x_m = \left|x\right| \\ y_m = \left|y\right| \\ z_m = \left|z\right| \\ [x_m, y_m, z_m] = \mathsf{sort}([x_m, y_m, z_m])\\ \\ z\_m \end{array} \]
x_m = (fabs.f64 x)
y_m = (fabs.f64 y)
z_m = (fabs.f64 z)
NOTE: x_m, y_m, and z_m should be sorted in increasing order before calling this function.
(FPCore (x_m y_m z_m) :precision binary64 z_m)
x_m = fabs(x);
y_m = fabs(y);
z_m = fabs(z);
assert(x_m < y_m && y_m < z_m);
double code(double x_m, double y_m, double z_m) {
	return z_m;
}
x_m =     private
y_m =     private
z_m =     private
NOTE: x_m, y_m, and z_m should be sorted in increasing order before calling this function.
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_m, y_m, z_m)
use fmin_fmax_functions
    real(8), intent (in) :: x_m
    real(8), intent (in) :: y_m
    real(8), intent (in) :: z_m
    code = z_m
end function
x_m = Math.abs(x);
y_m = Math.abs(y);
z_m = Math.abs(z);
assert x_m < y_m && y_m < z_m;
public static double code(double x_m, double y_m, double z_m) {
	return z_m;
}
x_m = math.fabs(x)
y_m = math.fabs(y)
z_m = math.fabs(z)
[x_m, y_m, z_m] = sort([x_m, y_m, z_m])
def code(x_m, y_m, z_m):
	return z_m
x_m = abs(x)
y_m = abs(y)
z_m = abs(z)
x_m, y_m, z_m = sort([x_m, y_m, z_m])
function code(x_m, y_m, z_m)
	return z_m
end
x_m = abs(x);
y_m = abs(y);
z_m = abs(z);
x_m, y_m, z_m = num2cell(sort([x_m, y_m, z_m])){:}
function tmp = code(x_m, y_m, z_m)
	tmp = z_m;
end
x_m = N[Abs[x], $MachinePrecision]
y_m = N[Abs[y], $MachinePrecision]
z_m = N[Abs[z], $MachinePrecision]
NOTE: x_m, y_m, and z_m should be sorted in increasing order before calling this function.
code[x$95$m_, y$95$m_, z$95$m_] := z$95$m
\begin{array}{l}
x_m = \left|x\right|
\\
y_m = \left|y\right|
\\
z_m = \left|z\right|
\\
[x_m, y_m, z_m] = \mathsf{sort}([x_m, y_m, z_m])\\
\\
z\_m
\end{array}
Derivation
  1. Initial program 45.6%

    \[\sqrt{x \cdot x + \left(y \cdot y + z \cdot z\right)} \]
  2. Taylor expanded in z around inf

    \[\leadsto \color{blue}{z} \]
  3. Step-by-step derivation
    1. Applied rewrites98.4%

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

    Alternative 2: 5.7% accurate, 32.0× speedup?

    \[\begin{array}{l} x_m = \left|x\right| \\ y_m = \left|y\right| \\ z_m = \left|z\right| \\ [x_m, y_m, z_m] = \mathsf{sort}([x_m, y_m, z_m])\\ \\ y\_m \end{array} \]
    x_m = (fabs.f64 x)
    y_m = (fabs.f64 y)
    z_m = (fabs.f64 z)
    NOTE: x_m, y_m, and z_m should be sorted in increasing order before calling this function.
    (FPCore (x_m y_m z_m) :precision binary64 y_m)
    x_m = fabs(x);
    y_m = fabs(y);
    z_m = fabs(z);
    assert(x_m < y_m && y_m < z_m);
    double code(double x_m, double y_m, double z_m) {
    	return y_m;
    }
    
    x_m =     private
    y_m =     private
    z_m =     private
    NOTE: x_m, y_m, and z_m should be sorted in increasing order before calling this function.
    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_m, y_m, z_m)
    use fmin_fmax_functions
        real(8), intent (in) :: x_m
        real(8), intent (in) :: y_m
        real(8), intent (in) :: z_m
        code = y_m
    end function
    
    x_m = Math.abs(x);
    y_m = Math.abs(y);
    z_m = Math.abs(z);
    assert x_m < y_m && y_m < z_m;
    public static double code(double x_m, double y_m, double z_m) {
    	return y_m;
    }
    
    x_m = math.fabs(x)
    y_m = math.fabs(y)
    z_m = math.fabs(z)
    [x_m, y_m, z_m] = sort([x_m, y_m, z_m])
    def code(x_m, y_m, z_m):
    	return y_m
    
    x_m = abs(x)
    y_m = abs(y)
    z_m = abs(z)
    x_m, y_m, z_m = sort([x_m, y_m, z_m])
    function code(x_m, y_m, z_m)
    	return y_m
    end
    
    x_m = abs(x);
    y_m = abs(y);
    z_m = abs(z);
    x_m, y_m, z_m = num2cell(sort([x_m, y_m, z_m])){:}
    function tmp = code(x_m, y_m, z_m)
    	tmp = y_m;
    end
    
    x_m = N[Abs[x], $MachinePrecision]
    y_m = N[Abs[y], $MachinePrecision]
    z_m = N[Abs[z], $MachinePrecision]
    NOTE: x_m, y_m, and z_m should be sorted in increasing order before calling this function.
    code[x$95$m_, y$95$m_, z$95$m_] := y$95$m
    
    \begin{array}{l}
    x_m = \left|x\right|
    \\
    y_m = \left|y\right|
    \\
    z_m = \left|z\right|
    \\
    [x_m, y_m, z_m] = \mathsf{sort}([x_m, y_m, z_m])\\
    \\
    y\_m
    \end{array}
    
    Derivation
    1. Initial program 45.6%

      \[\sqrt{x \cdot x + \left(y \cdot y + z \cdot z\right)} \]
    2. Taylor expanded in y around inf

      \[\leadsto \color{blue}{y} \]
    3. Step-by-step derivation
      1. Applied rewrites5.7%

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

      Alternative 3: 3.4% accurate, 32.0× speedup?

      \[\begin{array}{l} x_m = \left|x\right| \\ y_m = \left|y\right| \\ z_m = \left|z\right| \\ [x_m, y_m, z_m] = \mathsf{sort}([x_m, y_m, z_m])\\ \\ x\_m \end{array} \]
      x_m = (fabs.f64 x)
      y_m = (fabs.f64 y)
      z_m = (fabs.f64 z)
      NOTE: x_m, y_m, and z_m should be sorted in increasing order before calling this function.
      (FPCore (x_m y_m z_m) :precision binary64 x_m)
      x_m = fabs(x);
      y_m = fabs(y);
      z_m = fabs(z);
      assert(x_m < y_m && y_m < z_m);
      double code(double x_m, double y_m, double z_m) {
      	return x_m;
      }
      
      x_m =     private
      y_m =     private
      z_m =     private
      NOTE: x_m, y_m, and z_m should be sorted in increasing order before calling this function.
      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_m, y_m, z_m)
      use fmin_fmax_functions
          real(8), intent (in) :: x_m
          real(8), intent (in) :: y_m
          real(8), intent (in) :: z_m
          code = x_m
      end function
      
      x_m = Math.abs(x);
      y_m = Math.abs(y);
      z_m = Math.abs(z);
      assert x_m < y_m && y_m < z_m;
      public static double code(double x_m, double y_m, double z_m) {
      	return x_m;
      }
      
      x_m = math.fabs(x)
      y_m = math.fabs(y)
      z_m = math.fabs(z)
      [x_m, y_m, z_m] = sort([x_m, y_m, z_m])
      def code(x_m, y_m, z_m):
      	return x_m
      
      x_m = abs(x)
      y_m = abs(y)
      z_m = abs(z)
      x_m, y_m, z_m = sort([x_m, y_m, z_m])
      function code(x_m, y_m, z_m)
      	return x_m
      end
      
      x_m = abs(x);
      y_m = abs(y);
      z_m = abs(z);
      x_m, y_m, z_m = num2cell(sort([x_m, y_m, z_m])){:}
      function tmp = code(x_m, y_m, z_m)
      	tmp = x_m;
      end
      
      x_m = N[Abs[x], $MachinePrecision]
      y_m = N[Abs[y], $MachinePrecision]
      z_m = N[Abs[z], $MachinePrecision]
      NOTE: x_m, y_m, and z_m should be sorted in increasing order before calling this function.
      code[x$95$m_, y$95$m_, z$95$m_] := x$95$m
      
      \begin{array}{l}
      x_m = \left|x\right|
      \\
      y_m = \left|y\right|
      \\
      z_m = \left|z\right|
      \\
      [x_m, y_m, z_m] = \mathsf{sort}([x_m, y_m, z_m])\\
      \\
      x\_m
      \end{array}
      
      Derivation
      1. Initial program 45.6%

        \[\sqrt{x \cdot x + \left(y \cdot y + z \cdot z\right)} \]
      2. Taylor expanded in x around inf

        \[\leadsto \color{blue}{x} \]
      3. Step-by-step derivation
        1. Applied rewrites3.4%

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

        Developer Target 1: 100.0% accurate, 0.2× speedup?

        \[\begin{array}{l} \\ \mathsf{hypot}\left(x, \mathsf{hypot}\left(y, z\right)\right) \end{array} \]
        (FPCore (x y z) :precision binary64 (hypot x (hypot y z)))
        double code(double x, double y, double z) {
        	return hypot(x, hypot(y, z));
        }
        
        public static double code(double x, double y, double z) {
        	return Math.hypot(x, Math.hypot(y, z));
        }
        
        def code(x, y, z):
        	return math.hypot(x, math.hypot(y, z))
        
        function code(x, y, z)
        	return hypot(x, hypot(y, z))
        end
        
        function tmp = code(x, y, z)
        	tmp = hypot(x, hypot(y, z));
        end
        
        code[x_, y_, z_] := N[Sqrt[x ^ 2 + N[Sqrt[y ^ 2 + z ^ 2], $MachinePrecision] ^ 2], $MachinePrecision]
        
        \begin{array}{l}
        
        \\
        \mathsf{hypot}\left(x, \mathsf{hypot}\left(y, z\right)\right)
        \end{array}
        

        Reproduce

        ?
        herbie shell --seed 2025093 
        (FPCore (x y z)
          :name "bug366 (missed optimization)"
          :precision binary64
        
          :alt
          (! :herbie-platform default (hypot x (hypot y z)))
        
          (sqrt (+ (* x x) (+ (* y y) (* z z)))))