FRP.Yampa.Vector3:vector3Rho from Yampa-0.10.2

Percentage Accurate: 45.1% → 99.2%
Time: 6.9s
Alternatives: 5
Speedup: 1.4×

Specification

?
\[\begin{array}{l} \\ \sqrt{\left(x \cdot x + y \cdot y\right) + z \cdot z} \end{array} \]
(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)));
}
real(8) function code(x, y, z)
    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(Float64(x * x) + 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[(N[(x * x), $MachinePrecision] + N[(y * y), $MachinePrecision]), $MachinePrecision] + N[(z * z), $MachinePrecision]), $MachinePrecision]], $MachinePrecision]
\begin{array}{l}

\\
\sqrt{\left(x \cdot x + y \cdot y\right) + z \cdot z}
\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 5 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: 45.1% accurate, 1.0× speedup?

\[\begin{array}{l} \\ \sqrt{\left(x \cdot x + y \cdot y\right) + z \cdot z} \end{array} \]
(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)));
}
real(8) function code(x, y, z)
    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(Float64(x * x) + 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[(N[(x * x), $MachinePrecision] + N[(y * y), $MachinePrecision]), $MachinePrecision] + N[(z * z), $MachinePrecision]), $MachinePrecision]], $MachinePrecision]
\begin{array}{l}

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

Alternative 1: 99.2% accurate, 1.4× speedup?

\[\begin{array}{l} z_m = \left|z\right| \\ y_m = \left|y\right| \\ x_m = \left|x\right| \\ [x_m, y_m, z_m] = \mathsf{sort}([x_m, y_m, z_m])\\ \\ \mathsf{fma}\left(y\_m, \frac{y\_m \cdot 0.5}{z\_m}, z\_m\right) \end{array} \]
z_m = (fabs.f64 z)
y_m = (fabs.f64 y)
x_m = (fabs.f64 x)
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 (fma y_m (/ (* y_m 0.5) z_m) z_m))
z_m = fabs(z);
y_m = fabs(y);
x_m = fabs(x);
assert(x_m < y_m && y_m < z_m);
double code(double x_m, double y_m, double z_m) {
	return fma(y_m, ((y_m * 0.5) / z_m), z_m);
}
z_m = abs(z)
y_m = abs(y)
x_m = abs(x)
x_m, y_m, z_m = sort([x_m, y_m, z_m])
function code(x_m, y_m, z_m)
	return fma(y_m, Float64(Float64(y_m * 0.5) / z_m), z_m)
end
z_m = N[Abs[z], $MachinePrecision]
y_m = N[Abs[y], $MachinePrecision]
x_m = N[Abs[x], $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_] := N[(y$95$m * N[(N[(y$95$m * 0.5), $MachinePrecision] / z$95$m), $MachinePrecision] + z$95$m), $MachinePrecision]
\begin{array}{l}
z_m = \left|z\right|
\\
y_m = \left|y\right|
\\
x_m = \left|x\right|
\\
[x_m, y_m, z_m] = \mathsf{sort}([x_m, y_m, z_m])\\
\\
\mathsf{fma}\left(y\_m, \frac{y\_m \cdot 0.5}{z\_m}, z\_m\right)
\end{array}
Derivation
  1. Initial program 39.4%

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

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

      \[\leadsto z \cdot \color{blue}{\left(\frac{1}{2} \cdot \frac{{x}^{2} + {y}^{2}}{{z}^{2}} + 1\right)} \]
    2. distribute-rgt-inN/A

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

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

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

      \[\leadsto \frac{1}{2} \cdot \color{blue}{\frac{z \cdot \left({x}^{2} + {y}^{2}\right)}{{z}^{2}}} + 1 \cdot z \]
    6. unpow2N/A

      \[\leadsto \frac{1}{2} \cdot \frac{z \cdot \left({x}^{2} + {y}^{2}\right)}{\color{blue}{z \cdot z}} + 1 \cdot z \]
    7. times-fracN/A

      \[\leadsto \frac{1}{2} \cdot \color{blue}{\left(\frac{z}{z} \cdot \frac{{x}^{2} + {y}^{2}}{z}\right)} + 1 \cdot z \]
    8. *-inversesN/A

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

      \[\leadsto \frac{1}{2} \cdot \color{blue}{\frac{1 \cdot \left({x}^{2} + {y}^{2}\right)}{z}} + 1 \cdot z \]
    10. *-lft-identityN/A

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

      \[\leadsto \frac{1}{2} \cdot \frac{{x}^{2} + {y}^{2}}{z} + \color{blue}{z} \]
    12. lower-fma.f64N/A

      \[\leadsto \color{blue}{\mathsf{fma}\left(\frac{1}{2}, \frac{{x}^{2} + {y}^{2}}{z}, z\right)} \]
  5. Applied rewrites84.9%

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

    \[\leadsto z + \color{blue}{\frac{1}{2} \cdot \frac{{y}^{2}}{z}} \]
  7. Step-by-step derivation
    1. Applied rewrites99.4%

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

    Alternative 2: 45.1% accurate, 1.5× speedup?

    \[\begin{array}{l} z_m = \left|z\right| \\ y_m = \left|y\right| \\ x_m = \left|x\right| \\ [x_m, y_m, z_m] = \mathsf{sort}([x_m, y_m, z_m])\\ \\ \sqrt{\mathsf{fma}\left(z\_m, z\_m, y\_m \cdot y\_m\right)} \end{array} \]
    z_m = (fabs.f64 z)
    y_m = (fabs.f64 y)
    x_m = (fabs.f64 x)
    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 (sqrt (fma z_m z_m (* y_m y_m))))
    z_m = fabs(z);
    y_m = fabs(y);
    x_m = fabs(x);
    assert(x_m < y_m && y_m < z_m);
    double code(double x_m, double y_m, double z_m) {
    	return sqrt(fma(z_m, z_m, (y_m * y_m)));
    }
    
    z_m = abs(z)
    y_m = abs(y)
    x_m = abs(x)
    x_m, y_m, z_m = sort([x_m, y_m, z_m])
    function code(x_m, y_m, z_m)
    	return sqrt(fma(z_m, z_m, Float64(y_m * y_m)))
    end
    
    z_m = N[Abs[z], $MachinePrecision]
    y_m = N[Abs[y], $MachinePrecision]
    x_m = N[Abs[x], $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_] := N[Sqrt[N[(z$95$m * z$95$m + N[(y$95$m * y$95$m), $MachinePrecision]), $MachinePrecision]], $MachinePrecision]
    
    \begin{array}{l}
    z_m = \left|z\right|
    \\
    y_m = \left|y\right|
    \\
    x_m = \left|x\right|
    \\
    [x_m, y_m, z_m] = \mathsf{sort}([x_m, y_m, z_m])\\
    \\
    \sqrt{\mathsf{fma}\left(z\_m, z\_m, y\_m \cdot y\_m\right)}
    \end{array}
    
    Derivation
    1. Initial program 45.1%

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

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

        \[\leadsto \sqrt{\color{blue}{{z}^{2} + {y}^{2}}} \]
      2. unpow2N/A

        \[\leadsto \sqrt{\color{blue}{z \cdot z} + {y}^{2}} \]
      3. lower-fma.f64N/A

        \[\leadsto \sqrt{\color{blue}{\mathsf{fma}\left(z, z, {y}^{2}\right)}} \]
      4. unpow2N/A

        \[\leadsto \sqrt{\mathsf{fma}\left(z, z, \color{blue}{y \cdot y}\right)} \]
      5. lower-*.f6445.1

        \[\leadsto \sqrt{\mathsf{fma}\left(z, z, \color{blue}{y \cdot y}\right)} \]
    5. Applied rewrites45.1%

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

    Developer Target 1: 97.8% accurate, 0.7× speedup?

    \[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;z < -6.396479394109776 \cdot 10^{+136}:\\ \;\;\;\;-z\\ \mathbf{elif}\;z < 7.320293694404182 \cdot 10^{+117}:\\ \;\;\;\;\sqrt{\left(z \cdot z + x \cdot x\right) + y \cdot y}\\ \mathbf{else}:\\ \;\;\;\;z\\ \end{array} \end{array} \]
    (FPCore (x y z)
     :precision binary64
     (if (< z -6.396479394109776e+136)
       (- z)
       (if (< z 7.320293694404182e+117) (sqrt (+ (+ (* z z) (* x x)) (* y y))) z)))
    double code(double x, double y, double z) {
    	double tmp;
    	if (z < -6.396479394109776e+136) {
    		tmp = -z;
    	} else if (z < 7.320293694404182e+117) {
    		tmp = sqrt((((z * z) + (x * x)) + (y * y)));
    	} else {
    		tmp = z;
    	}
    	return tmp;
    }
    
    real(8) function code(x, y, z)
        real(8), intent (in) :: x
        real(8), intent (in) :: y
        real(8), intent (in) :: z
        real(8) :: tmp
        if (z < (-6.396479394109776d+136)) then
            tmp = -z
        else if (z < 7.320293694404182d+117) then
            tmp = sqrt((((z * z) + (x * x)) + (y * y)))
        else
            tmp = z
        end if
        code = tmp
    end function
    
    public static double code(double x, double y, double z) {
    	double tmp;
    	if (z < -6.396479394109776e+136) {
    		tmp = -z;
    	} else if (z < 7.320293694404182e+117) {
    		tmp = Math.sqrt((((z * z) + (x * x)) + (y * y)));
    	} else {
    		tmp = z;
    	}
    	return tmp;
    }
    
    def code(x, y, z):
    	tmp = 0
    	if z < -6.396479394109776e+136:
    		tmp = -z
    	elif z < 7.320293694404182e+117:
    		tmp = math.sqrt((((z * z) + (x * x)) + (y * y)))
    	else:
    		tmp = z
    	return tmp
    
    function code(x, y, z)
    	tmp = 0.0
    	if (z < -6.396479394109776e+136)
    		tmp = Float64(-z);
    	elseif (z < 7.320293694404182e+117)
    		tmp = sqrt(Float64(Float64(Float64(z * z) + Float64(x * x)) + Float64(y * y)));
    	else
    		tmp = z;
    	end
    	return tmp
    end
    
    function tmp_2 = code(x, y, z)
    	tmp = 0.0;
    	if (z < -6.396479394109776e+136)
    		tmp = -z;
    	elseif (z < 7.320293694404182e+117)
    		tmp = sqrt((((z * z) + (x * x)) + (y * y)));
    	else
    		tmp = z;
    	end
    	tmp_2 = tmp;
    end
    
    code[x_, y_, z_] := If[Less[z, -6.396479394109776e+136], (-z), If[Less[z, 7.320293694404182e+117], N[Sqrt[N[(N[(N[(z * z), $MachinePrecision] + N[(x * x), $MachinePrecision]), $MachinePrecision] + N[(y * y), $MachinePrecision]), $MachinePrecision]], $MachinePrecision], z]]
    
    \begin{array}{l}
    
    \\
    \begin{array}{l}
    \mathbf{if}\;z < -6.396479394109776 \cdot 10^{+136}:\\
    \;\;\;\;-z\\
    
    \mathbf{elif}\;z < 7.320293694404182 \cdot 10^{+117}:\\
    \;\;\;\;\sqrt{\left(z \cdot z + x \cdot x\right) + y \cdot y}\\
    
    \mathbf{else}:\\
    \;\;\;\;z\\
    
    
    \end{array}
    \end{array}
    

    Reproduce

    ?
    herbie shell --seed 2024230 
    (FPCore (x y z)
      :name "FRP.Yampa.Vector3:vector3Rho from Yampa-0.10.2"
      :precision binary64
    
      :alt
      (! :herbie-platform default (if (< z -63964793941097760000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000) (- z) (if (< z 7320293694404182000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000) (sqrt (+ (+ (* z z) (* x x)) (* y y))) z)))
    
      (sqrt (+ (+ (* x x) (* y y)) (* z z))))