Data.Octree.Internal:octantDistance from Octree-0.5.4.2

Percentage Accurate: 54.0% → 100.0%
Time: 8.5s
Alternatives: 6
Speedup: 0.2×

Specification

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

\\
\sqrt{x \cdot x + 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 6 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: 54.0% accurate, 1.0× speedup?

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

\\
\sqrt{x \cdot x + y \cdot y}
\end{array}

Alternative 1: 100.0% accurate, 0.2× speedup?

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

\\
\mathsf{hypot}\left(y, x\right)
\end{array}
Derivation
  1. Initial program 56.0%

    \[\sqrt{x \cdot x + y \cdot y} \]
  2. Add Preprocessing
  3. Step-by-step derivation
    1. lift-sqrt.f64N/A

      \[\leadsto \color{blue}{\sqrt{x \cdot x + y \cdot y}} \]
    2. lift-+.f64N/A

      \[\leadsto \sqrt{\color{blue}{x \cdot x + y \cdot y}} \]
    3. +-commutativeN/A

      \[\leadsto \sqrt{\color{blue}{y \cdot y + x \cdot x}} \]
    4. lift-*.f64N/A

      \[\leadsto \sqrt{\color{blue}{y \cdot y} + x \cdot x} \]
    5. lift-*.f64N/A

      \[\leadsto \sqrt{y \cdot y + \color{blue}{x \cdot x}} \]
    6. lower-hypot.f64100.0

      \[\leadsto \color{blue}{\mathsf{hypot}\left(y, x\right)} \]
  4. Applied rewrites100.0%

    \[\leadsto \color{blue}{\mathsf{hypot}\left(y, x\right)} \]
  5. Add Preprocessing

Alternative 2: 26.4% accurate, 0.3× speedup?

\[\begin{array}{l} \\ \begin{array}{l} t_0 := \mathsf{fma}\left(\frac{0.5}{y} \cdot x, x, -y\right)\\ t\_0 \cdot \frac{\mathsf{fma}\left(0.5 \cdot x, \frac{x}{y}, y\right)}{t\_0} \end{array} \end{array} \]
(FPCore (x y)
 :precision binary64
 (let* ((t_0 (fma (* (/ 0.5 y) x) x (- y))))
   (* t_0 (/ (fma (* 0.5 x) (/ x y) y) t_0))))
double code(double x, double y) {
	double t_0 = fma(((0.5 / y) * x), x, -y);
	return t_0 * (fma((0.5 * x), (x / y), y) / t_0);
}
function code(x, y)
	t_0 = fma(Float64(Float64(0.5 / y) * x), x, Float64(-y))
	return Float64(t_0 * Float64(fma(Float64(0.5 * x), Float64(x / y), y) / t_0))
end
code[x_, y_] := Block[{t$95$0 = N[(N[(N[(0.5 / y), $MachinePrecision] * x), $MachinePrecision] * x + (-y)), $MachinePrecision]}, N[(t$95$0 * N[(N[(N[(0.5 * x), $MachinePrecision] * N[(x / y), $MachinePrecision] + y), $MachinePrecision] / t$95$0), $MachinePrecision]), $MachinePrecision]]
\begin{array}{l}

\\
\begin{array}{l}
t_0 := \mathsf{fma}\left(\frac{0.5}{y} \cdot x, x, -y\right)\\
t\_0 \cdot \frac{\mathsf{fma}\left(0.5 \cdot x, \frac{x}{y}, y\right)}{t\_0}
\end{array}
\end{array}
Derivation
  1. Initial program 56.0%

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

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

      \[\leadsto \color{blue}{\frac{1}{2} \cdot \frac{{x}^{2}}{y} + y} \]
    2. *-lft-identityN/A

      \[\leadsto \frac{1}{2} \cdot \frac{\color{blue}{1 \cdot {x}^{2}}}{y} + y \]
    3. associate-*l/N/A

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

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

      \[\leadsto \color{blue}{\mathsf{fma}\left(\frac{1}{2} \cdot \frac{1}{y}, {x}^{2}, y\right)} \]
    6. associate-*r/N/A

      \[\leadsto \mathsf{fma}\left(\color{blue}{\frac{\frac{1}{2} \cdot 1}{y}}, {x}^{2}, y\right) \]
    7. metadata-evalN/A

      \[\leadsto \mathsf{fma}\left(\frac{\color{blue}{\frac{1}{2}}}{y}, {x}^{2}, y\right) \]
    8. lower-/.f64N/A

      \[\leadsto \mathsf{fma}\left(\color{blue}{\frac{\frac{1}{2}}{y}}, {x}^{2}, y\right) \]
    9. unpow2N/A

      \[\leadsto \mathsf{fma}\left(\frac{\frac{1}{2}}{y}, \color{blue}{x \cdot x}, y\right) \]
    10. lower-*.f6427.5

      \[\leadsto \mathsf{fma}\left(\frac{0.5}{y}, \color{blue}{x \cdot x}, y\right) \]
  5. Applied rewrites27.5%

    \[\leadsto \color{blue}{\mathsf{fma}\left(\frac{0.5}{y}, x \cdot x, y\right)} \]
  6. Step-by-step derivation
    1. Applied rewrites28.3%

      \[\leadsto \mathsf{fma}\left(\frac{0.5}{y} \cdot x, \color{blue}{x}, y\right) \]
    2. Step-by-step derivation
      1. Applied rewrites27.6%

        \[\leadsto \mathsf{fma}\left(\frac{0.5}{y} \cdot x, x, -y\right) \cdot \color{blue}{\frac{\frac{x}{y} \cdot \left(0.5 \cdot x\right) - \left(-y\right)}{\frac{x}{y} \cdot \left(0.5 \cdot x\right) - y}} \]
      2. Applied rewrites27.6%

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

      Alternative 3: 27.2% accurate, 1.0× speedup?

      \[\begin{array}{l} \\ \mathsf{fma}\left(\frac{0.5}{y} \cdot x, x, y\right) \end{array} \]
      (FPCore (x y) :precision binary64 (fma (* (/ 0.5 y) x) x y))
      double code(double x, double y) {
      	return fma(((0.5 / y) * x), x, y);
      }
      
      function code(x, y)
      	return fma(Float64(Float64(0.5 / y) * x), x, y)
      end
      
      code[x_, y_] := N[(N[(N[(0.5 / y), $MachinePrecision] * x), $MachinePrecision] * x + y), $MachinePrecision]
      
      \begin{array}{l}
      
      \\
      \mathsf{fma}\left(\frac{0.5}{y} \cdot x, x, y\right)
      \end{array}
      
      Derivation
      1. Initial program 56.0%

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

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

          \[\leadsto \color{blue}{\frac{1}{2} \cdot \frac{{x}^{2}}{y} + y} \]
        2. *-lft-identityN/A

          \[\leadsto \frac{1}{2} \cdot \frac{\color{blue}{1 \cdot {x}^{2}}}{y} + y \]
        3. associate-*l/N/A

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

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

          \[\leadsto \color{blue}{\mathsf{fma}\left(\frac{1}{2} \cdot \frac{1}{y}, {x}^{2}, y\right)} \]
        6. associate-*r/N/A

          \[\leadsto \mathsf{fma}\left(\color{blue}{\frac{\frac{1}{2} \cdot 1}{y}}, {x}^{2}, y\right) \]
        7. metadata-evalN/A

          \[\leadsto \mathsf{fma}\left(\frac{\color{blue}{\frac{1}{2}}}{y}, {x}^{2}, y\right) \]
        8. lower-/.f64N/A

          \[\leadsto \mathsf{fma}\left(\color{blue}{\frac{\frac{1}{2}}{y}}, {x}^{2}, y\right) \]
        9. unpow2N/A

          \[\leadsto \mathsf{fma}\left(\frac{\frac{1}{2}}{y}, \color{blue}{x \cdot x}, y\right) \]
        10. lower-*.f6427.5

          \[\leadsto \mathsf{fma}\left(\frac{0.5}{y}, \color{blue}{x \cdot x}, y\right) \]
      5. Applied rewrites27.5%

        \[\leadsto \color{blue}{\mathsf{fma}\left(\frac{0.5}{y}, x \cdot x, y\right)} \]
      6. Step-by-step derivation
        1. Applied rewrites28.3%

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

        Alternative 4: 54.0% accurate, 1.1× speedup?

        \[\begin{array}{l} \\ \sqrt{\mathsf{fma}\left(y, y, x \cdot x\right)} \end{array} \]
        (FPCore (x y) :precision binary64 (sqrt (fma y y (* x x))))
        double code(double x, double y) {
        	return sqrt(fma(y, y, (x * x)));
        }
        
        function code(x, y)
        	return sqrt(fma(y, y, Float64(x * x)))
        end
        
        code[x_, y_] := N[Sqrt[N[(y * y + N[(x * x), $MachinePrecision]), $MachinePrecision]], $MachinePrecision]
        
        \begin{array}{l}
        
        \\
        \sqrt{\mathsf{fma}\left(y, y, x \cdot x\right)}
        \end{array}
        
        Derivation
        1. Initial program 56.0%

          \[\sqrt{x \cdot x + y \cdot y} \]
        2. Add Preprocessing
        3. Step-by-step derivation
          1. lift-+.f64N/A

            \[\leadsto \sqrt{\color{blue}{x \cdot x + y \cdot y}} \]
          2. +-commutativeN/A

            \[\leadsto \sqrt{\color{blue}{y \cdot y + x \cdot x}} \]
          3. lift-*.f64N/A

            \[\leadsto \sqrt{\color{blue}{y \cdot y} + x \cdot x} \]
          4. lower-fma.f6456.0

            \[\leadsto \sqrt{\color{blue}{\mathsf{fma}\left(y, y, x \cdot x\right)}} \]
        4. Applied rewrites56.0%

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

        Alternative 5: 29.7% accurate, 1.5× speedup?

        \[\begin{array}{l} \\ \sqrt{y \cdot y} \end{array} \]
        (FPCore (x y) :precision binary64 (sqrt (* y y)))
        double code(double x, double y) {
        	return sqrt((y * y));
        }
        
        real(8) function code(x, y)
            real(8), intent (in) :: x
            real(8), intent (in) :: y
            code = sqrt((y * y))
        end function
        
        public static double code(double x, double y) {
        	return Math.sqrt((y * y));
        }
        
        def code(x, y):
        	return math.sqrt((y * y))
        
        function code(x, y)
        	return sqrt(Float64(y * y))
        end
        
        function tmp = code(x, y)
        	tmp = sqrt((y * y));
        end
        
        code[x_, y_] := N[Sqrt[N[(y * y), $MachinePrecision]], $MachinePrecision]
        
        \begin{array}{l}
        
        \\
        \sqrt{y \cdot y}
        \end{array}
        
        Derivation
        1. Initial program 56.0%

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

          \[\leadsto \sqrt{\color{blue}{{y}^{2}}} \]
        4. Step-by-step derivation
          1. unpow2N/A

            \[\leadsto \sqrt{\color{blue}{y \cdot y}} \]
          2. lower-*.f6432.5

            \[\leadsto \sqrt{\color{blue}{y \cdot y}} \]
        5. Applied rewrites32.5%

          \[\leadsto \sqrt{\color{blue}{y \cdot y}} \]
        6. Add Preprocessing

        Alternative 6: 26.6% accurate, 8.0× speedup?

        \[\begin{array}{l} \\ -x \end{array} \]
        (FPCore (x y) :precision binary64 (- x))
        double code(double x, double y) {
        	return -x;
        }
        
        real(8) function code(x, y)
            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 Float64(-x)
        end
        
        function tmp = code(x, y)
        	tmp = -x;
        end
        
        code[x_, y_] := (-x)
        
        \begin{array}{l}
        
        \\
        -x
        \end{array}
        
        Derivation
        1. Initial program 56.0%

          \[\sqrt{x \cdot x + y \cdot y} \]
        2. Add Preprocessing
        3. Taylor expanded in x around -inf

          \[\leadsto \color{blue}{-1 \cdot x} \]
        4. Step-by-step derivation
          1. mul-1-negN/A

            \[\leadsto \color{blue}{\mathsf{neg}\left(x\right)} \]
          2. lower-neg.f6423.9

            \[\leadsto \color{blue}{-x} \]
        5. Applied rewrites23.9%

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

        Developer Target 1: 73.6% accurate, 0.7× speedup?

        \[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;x < -1.1236950826599826 \cdot 10^{+145}:\\ \;\;\;\;-x\\ \mathbf{elif}\;x < 1.116557621183362 \cdot 10^{+93}:\\ \;\;\;\;\sqrt{x \cdot x + y \cdot y}\\ \mathbf{else}:\\ \;\;\;\;x\\ \end{array} \end{array} \]
        (FPCore (x y)
         :precision binary64
         (if (< x -1.1236950826599826e+145)
           (- x)
           (if (< x 1.116557621183362e+93) (sqrt (+ (* x x) (* y y))) x)))
        double code(double x, double y) {
        	double tmp;
        	if (x < -1.1236950826599826e+145) {
        		tmp = -x;
        	} else if (x < 1.116557621183362e+93) {
        		tmp = sqrt(((x * x) + (y * y)));
        	} else {
        		tmp = x;
        	}
        	return tmp;
        }
        
        real(8) function code(x, y)
            real(8), intent (in) :: x
            real(8), intent (in) :: y
            real(8) :: tmp
            if (x < (-1.1236950826599826d+145)) then
                tmp = -x
            else if (x < 1.116557621183362d+93) then
                tmp = sqrt(((x * x) + (y * y)))
            else
                tmp = x
            end if
            code = tmp
        end function
        
        public static double code(double x, double y) {
        	double tmp;
        	if (x < -1.1236950826599826e+145) {
        		tmp = -x;
        	} else if (x < 1.116557621183362e+93) {
        		tmp = Math.sqrt(((x * x) + (y * y)));
        	} else {
        		tmp = x;
        	}
        	return tmp;
        }
        
        def code(x, y):
        	tmp = 0
        	if x < -1.1236950826599826e+145:
        		tmp = -x
        	elif x < 1.116557621183362e+93:
        		tmp = math.sqrt(((x * x) + (y * y)))
        	else:
        		tmp = x
        	return tmp
        
        function code(x, y)
        	tmp = 0.0
        	if (x < -1.1236950826599826e+145)
        		tmp = Float64(-x);
        	elseif (x < 1.116557621183362e+93)
        		tmp = sqrt(Float64(Float64(x * x) + Float64(y * y)));
        	else
        		tmp = x;
        	end
        	return tmp
        end
        
        function tmp_2 = code(x, y)
        	tmp = 0.0;
        	if (x < -1.1236950826599826e+145)
        		tmp = -x;
        	elseif (x < 1.116557621183362e+93)
        		tmp = sqrt(((x * x) + (y * y)));
        	else
        		tmp = x;
        	end
        	tmp_2 = tmp;
        end
        
        code[x_, y_] := If[Less[x, -1.1236950826599826e+145], (-x), If[Less[x, 1.116557621183362e+93], N[Sqrt[N[(N[(x * x), $MachinePrecision] + N[(y * y), $MachinePrecision]), $MachinePrecision]], $MachinePrecision], x]]
        
        \begin{array}{l}
        
        \\
        \begin{array}{l}
        \mathbf{if}\;x < -1.1236950826599826 \cdot 10^{+145}:\\
        \;\;\;\;-x\\
        
        \mathbf{elif}\;x < 1.116557621183362 \cdot 10^{+93}:\\
        \;\;\;\;\sqrt{x \cdot x + y \cdot y}\\
        
        \mathbf{else}:\\
        \;\;\;\;x\\
        
        
        \end{array}
        \end{array}
        

        Reproduce

        ?
        herbie shell --seed 2024339 
        (FPCore (x y)
          :name "Data.Octree.Internal:octantDistance  from Octree-0.5.4.2"
          :precision binary64
        
          :alt
          (! :herbie-platform default (if (< x -11236950826599826000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000) (- x) (if (< x 1116557621183362000000000000000000000000000000000000000000000000000000000000000000000000000000) (sqrt (+ (* x x) (* y y))) x)))
        
          (sqrt (+ (* x x) (* y y))))