Data.Colour.RGBSpace.HSV:hsv from colour-2.3.3, I

Percentage Accurate: 96.1% → 97.4%
Time: 6.3s
Alternatives: 4
Speedup: 1.0×

Specification

?
\[\begin{array}{l} \\ x \cdot \left(1 - y \cdot z\right) \end{array} \]
(FPCore (x y z) :precision binary64 (* x (- 1.0 (* y z))))
double code(double x, double y, double z) {
	return x * (1.0 - (y * z));
}
real(8) function code(x, y, z)
    real(8), intent (in) :: x
    real(8), intent (in) :: y
    real(8), intent (in) :: z
    code = x * (1.0d0 - (y * z))
end function
public static double code(double x, double y, double z) {
	return x * (1.0 - (y * z));
}
def code(x, y, z):
	return x * (1.0 - (y * z))
function code(x, y, z)
	return Float64(x * Float64(1.0 - Float64(y * z)))
end
function tmp = code(x, y, z)
	tmp = x * (1.0 - (y * z));
end
code[x_, y_, z_] := N[(x * N[(1.0 - N[(y * z), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}

\\
x \cdot \left(1 - y \cdot z\right)
\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 4 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: 96.1% accurate, 1.0× speedup?

\[\begin{array}{l} \\ x \cdot \left(1 - y \cdot z\right) \end{array} \]
(FPCore (x y z) :precision binary64 (* x (- 1.0 (* y z))))
double code(double x, double y, double z) {
	return x * (1.0 - (y * z));
}
real(8) function code(x, y, z)
    real(8), intent (in) :: x
    real(8), intent (in) :: y
    real(8), intent (in) :: z
    code = x * (1.0d0 - (y * z))
end function
public static double code(double x, double y, double z) {
	return x * (1.0 - (y * z));
}
def code(x, y, z):
	return x * (1.0 - (y * z))
function code(x, y, z)
	return Float64(x * Float64(1.0 - Float64(y * z)))
end
function tmp = code(x, y, z)
	tmp = x * (1.0 - (y * z));
end
code[x_, y_, z_] := N[(x * N[(1.0 - N[(y * z), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}

\\
x \cdot \left(1 - y \cdot z\right)
\end{array}

Alternative 1: 97.4% accurate, 0.6× speedup?

\[\begin{array}{l} [x, y, z] = \mathsf{sort}([x, y, z])\\ \\ \begin{array}{l} \mathbf{if}\;z \cdot y \leq 4 \cdot 10^{+107}:\\ \;\;\;\;\left(1 - z \cdot y\right) \cdot x\\ \mathbf{else}:\\ \;\;\;\;\mathsf{fma}\left(\left(-y\right) \cdot x, z, x\right)\\ \end{array} \end{array} \]
NOTE: x, y, and z should be sorted in increasing order before calling this function.
(FPCore (x y z)
 :precision binary64
 (if (<= (* z y) 4e+107) (* (- 1.0 (* z y)) x) (fma (* (- y) x) z x)))
assert(x < y && y < z);
double code(double x, double y, double z) {
	double tmp;
	if ((z * y) <= 4e+107) {
		tmp = (1.0 - (z * y)) * x;
	} else {
		tmp = fma((-y * x), z, x);
	}
	return tmp;
}
x, y, z = sort([x, y, z])
function code(x, y, z)
	tmp = 0.0
	if (Float64(z * y) <= 4e+107)
		tmp = Float64(Float64(1.0 - Float64(z * y)) * x);
	else
		tmp = fma(Float64(Float64(-y) * x), z, x);
	end
	return tmp
end
NOTE: x, y, and z should be sorted in increasing order before calling this function.
code[x_, y_, z_] := If[LessEqual[N[(z * y), $MachinePrecision], 4e+107], N[(N[(1.0 - N[(z * y), $MachinePrecision]), $MachinePrecision] * x), $MachinePrecision], N[(N[((-y) * x), $MachinePrecision] * z + x), $MachinePrecision]]
\begin{array}{l}
[x, y, z] = \mathsf{sort}([x, y, z])\\
\\
\begin{array}{l}
\mathbf{if}\;z \cdot y \leq 4 \cdot 10^{+107}:\\
\;\;\;\;\left(1 - z \cdot y\right) \cdot x\\

\mathbf{else}:\\
\;\;\;\;\mathsf{fma}\left(\left(-y\right) \cdot x, z, x\right)\\


\end{array}
\end{array}
Derivation
  1. Split input into 2 regimes
  2. if (*.f64 y z) < 3.9999999999999999e107

    1. Initial program 98.5%

      \[x \cdot \left(1 - y \cdot z\right) \]
    2. Add Preprocessing

    if 3.9999999999999999e107 < (*.f64 y z)

    1. Initial program 81.4%

      \[x \cdot \left(1 - y \cdot z\right) \]
    2. Add Preprocessing
    3. Step-by-step derivation
      1. lift-*.f64N/A

        \[\leadsto \color{blue}{x \cdot \left(1 - y \cdot z\right)} \]
      2. lift--.f64N/A

        \[\leadsto x \cdot \color{blue}{\left(1 - y \cdot z\right)} \]
      3. sub-negN/A

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

        \[\leadsto x \cdot \color{blue}{\left(\left(\mathsf{neg}\left(y \cdot z\right)\right) + 1\right)} \]
      5. distribute-lft-inN/A

        \[\leadsto \color{blue}{x \cdot \left(\mathsf{neg}\left(y \cdot z\right)\right) + x \cdot 1} \]
      6. lift-*.f64N/A

        \[\leadsto x \cdot \left(\mathsf{neg}\left(\color{blue}{y \cdot z}\right)\right) + x \cdot 1 \]
      7. distribute-lft-neg-inN/A

        \[\leadsto x \cdot \color{blue}{\left(\left(\mathsf{neg}\left(y\right)\right) \cdot z\right)} + x \cdot 1 \]
      8. associate-*r*N/A

        \[\leadsto \color{blue}{\left(x \cdot \left(\mathsf{neg}\left(y\right)\right)\right) \cdot z} + x \cdot 1 \]
      9. *-rgt-identityN/A

        \[\leadsto \left(x \cdot \left(\mathsf{neg}\left(y\right)\right)\right) \cdot z + \color{blue}{x} \]
      10. lower-fma.f64N/A

        \[\leadsto \color{blue}{\mathsf{fma}\left(x \cdot \left(\mathsf{neg}\left(y\right)\right), z, x\right)} \]
      11. lower-*.f64N/A

        \[\leadsto \mathsf{fma}\left(\color{blue}{x \cdot \left(\mathsf{neg}\left(y\right)\right)}, z, x\right) \]
      12. lower-neg.f6499.8

        \[\leadsto \mathsf{fma}\left(x \cdot \color{blue}{\left(-y\right)}, z, x\right) \]
    4. Applied rewrites99.8%

      \[\leadsto \color{blue}{\mathsf{fma}\left(x \cdot \left(-y\right), z, x\right)} \]
  3. Recombined 2 regimes into one program.
  4. Final simplification98.8%

    \[\leadsto \begin{array}{l} \mathbf{if}\;z \cdot y \leq 4 \cdot 10^{+107}:\\ \;\;\;\;\left(1 - z \cdot y\right) \cdot x\\ \mathbf{else}:\\ \;\;\;\;\mathsf{fma}\left(\left(-y\right) \cdot x, z, x\right)\\ \end{array} \]
  5. Add Preprocessing

Alternative 2: 94.1% accurate, 0.3× speedup?

\[\begin{array}{l} [x, y, z] = \mathsf{sort}([x, y, z])\\ \\ \begin{array}{l} t_0 := 1 - z \cdot y\\ t_1 := \left(\left(-y\right) \cdot z\right) \cdot x\\ \mathbf{if}\;t\_0 \leq -5000:\\ \;\;\;\;t\_1\\ \mathbf{elif}\;t\_0 \leq 2:\\ \;\;\;\;1 \cdot x\\ \mathbf{else}:\\ \;\;\;\;t\_1\\ \end{array} \end{array} \]
NOTE: x, y, and z should be sorted in increasing order before calling this function.
(FPCore (x y z)
 :precision binary64
 (let* ((t_0 (- 1.0 (* z y))) (t_1 (* (* (- y) z) x)))
   (if (<= t_0 -5000.0) t_1 (if (<= t_0 2.0) (* 1.0 x) t_1))))
assert(x < y && y < z);
double code(double x, double y, double z) {
	double t_0 = 1.0 - (z * y);
	double t_1 = (-y * z) * x;
	double tmp;
	if (t_0 <= -5000.0) {
		tmp = t_1;
	} else if (t_0 <= 2.0) {
		tmp = 1.0 * x;
	} else {
		tmp = t_1;
	}
	return tmp;
}
NOTE: x, y, and z should be sorted in increasing order before calling this function.
real(8) function code(x, y, z)
    real(8), intent (in) :: x
    real(8), intent (in) :: y
    real(8), intent (in) :: z
    real(8) :: t_0
    real(8) :: t_1
    real(8) :: tmp
    t_0 = 1.0d0 - (z * y)
    t_1 = (-y * z) * x
    if (t_0 <= (-5000.0d0)) then
        tmp = t_1
    else if (t_0 <= 2.0d0) then
        tmp = 1.0d0 * x
    else
        tmp = t_1
    end if
    code = tmp
end function
assert x < y && y < z;
public static double code(double x, double y, double z) {
	double t_0 = 1.0 - (z * y);
	double t_1 = (-y * z) * x;
	double tmp;
	if (t_0 <= -5000.0) {
		tmp = t_1;
	} else if (t_0 <= 2.0) {
		tmp = 1.0 * x;
	} else {
		tmp = t_1;
	}
	return tmp;
}
[x, y, z] = sort([x, y, z])
def code(x, y, z):
	t_0 = 1.0 - (z * y)
	t_1 = (-y * z) * x
	tmp = 0
	if t_0 <= -5000.0:
		tmp = t_1
	elif t_0 <= 2.0:
		tmp = 1.0 * x
	else:
		tmp = t_1
	return tmp
x, y, z = sort([x, y, z])
function code(x, y, z)
	t_0 = Float64(1.0 - Float64(z * y))
	t_1 = Float64(Float64(Float64(-y) * z) * x)
	tmp = 0.0
	if (t_0 <= -5000.0)
		tmp = t_1;
	elseif (t_0 <= 2.0)
		tmp = Float64(1.0 * x);
	else
		tmp = t_1;
	end
	return tmp
end
x, y, z = num2cell(sort([x, y, z])){:}
function tmp_2 = code(x, y, z)
	t_0 = 1.0 - (z * y);
	t_1 = (-y * z) * x;
	tmp = 0.0;
	if (t_0 <= -5000.0)
		tmp = t_1;
	elseif (t_0 <= 2.0)
		tmp = 1.0 * x;
	else
		tmp = t_1;
	end
	tmp_2 = tmp;
end
NOTE: x, y, and z should be sorted in increasing order before calling this function.
code[x_, y_, z_] := Block[{t$95$0 = N[(1.0 - N[(z * y), $MachinePrecision]), $MachinePrecision]}, Block[{t$95$1 = N[(N[((-y) * z), $MachinePrecision] * x), $MachinePrecision]}, If[LessEqual[t$95$0, -5000.0], t$95$1, If[LessEqual[t$95$0, 2.0], N[(1.0 * x), $MachinePrecision], t$95$1]]]]
\begin{array}{l}
[x, y, z] = \mathsf{sort}([x, y, z])\\
\\
\begin{array}{l}
t_0 := 1 - z \cdot y\\
t_1 := \left(\left(-y\right) \cdot z\right) \cdot x\\
\mathbf{if}\;t\_0 \leq -5000:\\
\;\;\;\;t\_1\\

\mathbf{elif}\;t\_0 \leq 2:\\
\;\;\;\;1 \cdot x\\

\mathbf{else}:\\
\;\;\;\;t\_1\\


\end{array}
\end{array}
Derivation
  1. Split input into 2 regimes
  2. if (-.f64 #s(literal 1 binary64) (*.f64 y z)) < -5e3 or 2 < (-.f64 #s(literal 1 binary64) (*.f64 y z))

    1. Initial program 90.9%

      \[x \cdot \left(1 - y \cdot z\right) \]
    2. Add Preprocessing
    3. Taylor expanded in y around inf

      \[\leadsto x \cdot \color{blue}{\left(-1 \cdot \left(y \cdot z\right)\right)} \]
    4. Step-by-step derivation
      1. associate-*r*N/A

        \[\leadsto x \cdot \color{blue}{\left(\left(-1 \cdot y\right) \cdot z\right)} \]
      2. lower-*.f64N/A

        \[\leadsto x \cdot \color{blue}{\left(\left(-1 \cdot y\right) \cdot z\right)} \]
      3. mul-1-negN/A

        \[\leadsto x \cdot \left(\color{blue}{\left(\mathsf{neg}\left(y\right)\right)} \cdot z\right) \]
      4. lower-neg.f6488.2

        \[\leadsto x \cdot \left(\color{blue}{\left(-y\right)} \cdot z\right) \]
    5. Applied rewrites88.2%

      \[\leadsto x \cdot \color{blue}{\left(\left(-y\right) \cdot z\right)} \]

    if -5e3 < (-.f64 #s(literal 1 binary64) (*.f64 y z)) < 2

    1. Initial program 100.0%

      \[x \cdot \left(1 - y \cdot z\right) \]
    2. Add Preprocessing
    3. Taylor expanded in y around 0

      \[\leadsto x \cdot \color{blue}{1} \]
    4. Step-by-step derivation
      1. Applied rewrites97.7%

        \[\leadsto x \cdot \color{blue}{1} \]
    5. Recombined 2 regimes into one program.
    6. Final simplification92.6%

      \[\leadsto \begin{array}{l} \mathbf{if}\;1 - z \cdot y \leq -5000:\\ \;\;\;\;\left(\left(-y\right) \cdot z\right) \cdot x\\ \mathbf{elif}\;1 - z \cdot y \leq 2:\\ \;\;\;\;1 \cdot x\\ \mathbf{else}:\\ \;\;\;\;\left(\left(-y\right) \cdot z\right) \cdot x\\ \end{array} \]
    7. Add Preprocessing

    Alternative 3: 96.1% accurate, 1.0× speedup?

    \[\begin{array}{l} [x, y, z] = \mathsf{sort}([x, y, z])\\ \\ \left(1 - z \cdot y\right) \cdot x \end{array} \]
    NOTE: x, y, and z should be sorted in increasing order before calling this function.
    (FPCore (x y z) :precision binary64 (* (- 1.0 (* z y)) x))
    assert(x < y && y < z);
    double code(double x, double y, double z) {
    	return (1.0 - (z * y)) * x;
    }
    
    NOTE: x, y, and z should be sorted in increasing order before calling this function.
    real(8) function code(x, y, z)
        real(8), intent (in) :: x
        real(8), intent (in) :: y
        real(8), intent (in) :: z
        code = (1.0d0 - (z * y)) * x
    end function
    
    assert x < y && y < z;
    public static double code(double x, double y, double z) {
    	return (1.0 - (z * y)) * x;
    }
    
    [x, y, z] = sort([x, y, z])
    def code(x, y, z):
    	return (1.0 - (z * y)) * x
    
    x, y, z = sort([x, y, z])
    function code(x, y, z)
    	return Float64(Float64(1.0 - Float64(z * y)) * x)
    end
    
    x, y, z = num2cell(sort([x, y, z])){:}
    function tmp = code(x, y, z)
    	tmp = (1.0 - (z * y)) * x;
    end
    
    NOTE: x, y, and z should be sorted in increasing order before calling this function.
    code[x_, y_, z_] := N[(N[(1.0 - N[(z * y), $MachinePrecision]), $MachinePrecision] * x), $MachinePrecision]
    
    \begin{array}{l}
    [x, y, z] = \mathsf{sort}([x, y, z])\\
    \\
    \left(1 - z \cdot y\right) \cdot x
    \end{array}
    
    Derivation
    1. Initial program 95.1%

      \[x \cdot \left(1 - y \cdot z\right) \]
    2. Add Preprocessing
    3. Final simplification95.1%

      \[\leadsto \left(1 - z \cdot y\right) \cdot x \]
    4. Add Preprocessing

    Alternative 4: 51.3% accurate, 2.3× speedup?

    \[\begin{array}{l} [x, y, z] = \mathsf{sort}([x, y, z])\\ \\ 1 \cdot x \end{array} \]
    NOTE: x, y, and z should be sorted in increasing order before calling this function.
    (FPCore (x y z) :precision binary64 (* 1.0 x))
    assert(x < y && y < z);
    double code(double x, double y, double z) {
    	return 1.0 * x;
    }
    
    NOTE: x, y, and z should be sorted in increasing order before calling this function.
    real(8) function code(x, y, z)
        real(8), intent (in) :: x
        real(8), intent (in) :: y
        real(8), intent (in) :: z
        code = 1.0d0 * x
    end function
    
    assert x < y && y < z;
    public static double code(double x, double y, double z) {
    	return 1.0 * x;
    }
    
    [x, y, z] = sort([x, y, z])
    def code(x, y, z):
    	return 1.0 * x
    
    x, y, z = sort([x, y, z])
    function code(x, y, z)
    	return Float64(1.0 * x)
    end
    
    x, y, z = num2cell(sort([x, y, z])){:}
    function tmp = code(x, y, z)
    	tmp = 1.0 * x;
    end
    
    NOTE: x, y, and z should be sorted in increasing order before calling this function.
    code[x_, y_, z_] := N[(1.0 * x), $MachinePrecision]
    
    \begin{array}{l}
    [x, y, z] = \mathsf{sort}([x, y, z])\\
    \\
    1 \cdot x
    \end{array}
    
    Derivation
    1. Initial program 95.1%

      \[x \cdot \left(1 - y \cdot z\right) \]
    2. Add Preprocessing
    3. Taylor expanded in y around 0

      \[\leadsto x \cdot \color{blue}{1} \]
    4. Step-by-step derivation
      1. Applied rewrites46.8%

        \[\leadsto x \cdot \color{blue}{1} \]
      2. Final simplification46.8%

        \[\leadsto 1 \cdot x \]
      3. Add Preprocessing

      Reproduce

      ?
      herbie shell --seed 2024294 
      (FPCore (x y z)
        :name "Data.Colour.RGBSpace.HSV:hsv from colour-2.3.3, I"
        :precision binary64
        (* x (- 1.0 (* y z))))