Data.Colour.CIE:cieLAB from colour-2.3.3, C

Percentage Accurate: 100.0% → 100.0%
Time: 3.1s
Alternatives: 5
Speedup: 1.0×

Specification

?
\[\begin{array}{l} \\ x + \frac{y}{500} \end{array} \]
(FPCore (x y) :precision binary64 (+ x (/ y 500.0)))
double code(double x, double y) {
	return x + (y / 500.0);
}
real(8) function code(x, y)
    real(8), intent (in) :: x
    real(8), intent (in) :: y
    code = x + (y / 500.0d0)
end function
public static double code(double x, double y) {
	return x + (y / 500.0);
}
def code(x, y):
	return x + (y / 500.0)
function code(x, y)
	return Float64(x + Float64(y / 500.0))
end
function tmp = code(x, y)
	tmp = x + (y / 500.0);
end
code[x_, y_] := N[(x + N[(y / 500.0), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}

\\
x + \frac{y}{500}
\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: 100.0% accurate, 1.0× speedup?

\[\begin{array}{l} \\ x + \frac{y}{500} \end{array} \]
(FPCore (x y) :precision binary64 (+ x (/ y 500.0)))
double code(double x, double y) {
	return x + (y / 500.0);
}
real(8) function code(x, y)
    real(8), intent (in) :: x
    real(8), intent (in) :: y
    code = x + (y / 500.0d0)
end function
public static double code(double x, double y) {
	return x + (y / 500.0);
}
def code(x, y):
	return x + (y / 500.0)
function code(x, y)
	return Float64(x + Float64(y / 500.0))
end
function tmp = code(x, y)
	tmp = x + (y / 500.0);
end
code[x_, y_] := N[(x + N[(y / 500.0), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}

\\
x + \frac{y}{500}
\end{array}

Alternative 1: 100.0% accurate, 1.0× speedup?

\[\begin{array}{l} \\ x + \frac{y}{500} \end{array} \]
(FPCore (x y) :precision binary64 (+ x (/ y 500.0)))
double code(double x, double y) {
	return x + (y / 500.0);
}
real(8) function code(x, y)
    real(8), intent (in) :: x
    real(8), intent (in) :: y
    code = x + (y / 500.0d0)
end function
public static double code(double x, double y) {
	return x + (y / 500.0);
}
def code(x, y):
	return x + (y / 500.0)
function code(x, y)
	return Float64(x + Float64(y / 500.0))
end
function tmp = code(x, y)
	tmp = x + (y / 500.0);
end
code[x_, y_] := N[(x + N[(y / 500.0), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}

\\
x + \frac{y}{500}
\end{array}
Derivation
  1. Initial program 100.0%

    \[x + \frac{y}{500} \]
  2. Add Preprocessing
  3. Add Preprocessing

Alternative 2: 74.5% accurate, 0.3× speedup?

\[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;\frac{y}{500} \leq -1 \cdot 10^{+80} \lor \neg \left(\frac{y}{500} \leq 10^{-16}\right):\\ \;\;\;\;\frac{y}{500}\\ \mathbf{else}:\\ \;\;\;\;x\\ \end{array} \end{array} \]
(FPCore (x y)
 :precision binary64
 (if (or (<= (/ y 500.0) -1e+80) (not (<= (/ y 500.0) 1e-16))) (/ y 500.0) x))
double code(double x, double y) {
	double tmp;
	if (((y / 500.0) <= -1e+80) || !((y / 500.0) <= 1e-16)) {
		tmp = y / 500.0;
	} 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 (((y / 500.0d0) <= (-1d+80)) .or. (.not. ((y / 500.0d0) <= 1d-16))) then
        tmp = y / 500.0d0
    else
        tmp = x
    end if
    code = tmp
end function
public static double code(double x, double y) {
	double tmp;
	if (((y / 500.0) <= -1e+80) || !((y / 500.0) <= 1e-16)) {
		tmp = y / 500.0;
	} else {
		tmp = x;
	}
	return tmp;
}
def code(x, y):
	tmp = 0
	if ((y / 500.0) <= -1e+80) or not ((y / 500.0) <= 1e-16):
		tmp = y / 500.0
	else:
		tmp = x
	return tmp
function code(x, y)
	tmp = 0.0
	if ((Float64(y / 500.0) <= -1e+80) || !(Float64(y / 500.0) <= 1e-16))
		tmp = Float64(y / 500.0);
	else
		tmp = x;
	end
	return tmp
end
function tmp_2 = code(x, y)
	tmp = 0.0;
	if (((y / 500.0) <= -1e+80) || ~(((y / 500.0) <= 1e-16)))
		tmp = y / 500.0;
	else
		tmp = x;
	end
	tmp_2 = tmp;
end
code[x_, y_] := If[Or[LessEqual[N[(y / 500.0), $MachinePrecision], -1e+80], N[Not[LessEqual[N[(y / 500.0), $MachinePrecision], 1e-16]], $MachinePrecision]], N[(y / 500.0), $MachinePrecision], x]
\begin{array}{l}

\\
\begin{array}{l}
\mathbf{if}\;\frac{y}{500} \leq -1 \cdot 10^{+80} \lor \neg \left(\frac{y}{500} \leq 10^{-16}\right):\\
\;\;\;\;\frac{y}{500}\\

\mathbf{else}:\\
\;\;\;\;x\\


\end{array}
\end{array}
Derivation
  1. Split input into 2 regimes
  2. if (/.f64 y #s(literal 500 binary64)) < -1e80 or 9.9999999999999998e-17 < (/.f64 y #s(literal 500 binary64))

    1. Initial program 100.0%

      \[x + \frac{y}{500} \]
    2. Step-by-step derivation
      1. *-rgt-identity100.0%

        \[\leadsto x + \color{blue}{\frac{y}{500} \cdot 1} \]
      2. metadata-eval100.0%

        \[\leadsto x + \frac{y}{500} \cdot \color{blue}{\left(--1\right)} \]
      3. associate-*l/100.0%

        \[\leadsto x + \color{blue}{\frac{y \cdot \left(--1\right)}{500}} \]
      4. associate-/l*99.8%

        \[\leadsto x + \color{blue}{y \cdot \frac{--1}{500}} \]
      5. metadata-eval99.8%

        \[\leadsto x + y \cdot \frac{\color{blue}{1}}{500} \]
      6. metadata-eval99.8%

        \[\leadsto x + y \cdot \color{blue}{0.002} \]
    3. Simplified99.8%

      \[\leadsto \color{blue}{x + y \cdot 0.002} \]
    4. Add Preprocessing
    5. Taylor expanded in y around inf 99.7%

      \[\leadsto \color{blue}{y \cdot \left(0.002 + \frac{x}{y}\right)} \]
    6. Taylor expanded in x around 0 81.8%

      \[\leadsto y \cdot \color{blue}{0.002} \]
    7. Step-by-step derivation
      1. metadata-eval81.8%

        \[\leadsto y \cdot \color{blue}{\frac{1}{500}} \]
      2. div-inv82.0%

        \[\leadsto \color{blue}{\frac{y}{500}} \]
    8. Applied egg-rr82.0%

      \[\leadsto \color{blue}{\frac{y}{500}} \]

    if -1e80 < (/.f64 y #s(literal 500 binary64)) < 9.9999999999999998e-17

    1. Initial program 100.0%

      \[x + \frac{y}{500} \]
    2. Step-by-step derivation
      1. *-rgt-identity100.0%

        \[\leadsto x + \color{blue}{\frac{y}{500} \cdot 1} \]
      2. metadata-eval100.0%

        \[\leadsto x + \frac{y}{500} \cdot \color{blue}{\left(--1\right)} \]
      3. associate-*l/100.0%

        \[\leadsto x + \color{blue}{\frac{y \cdot \left(--1\right)}{500}} \]
      4. associate-/l*99.9%

        \[\leadsto x + \color{blue}{y \cdot \frac{--1}{500}} \]
      5. metadata-eval99.9%

        \[\leadsto x + y \cdot \frac{\color{blue}{1}}{500} \]
      6. metadata-eval99.9%

        \[\leadsto x + y \cdot \color{blue}{0.002} \]
    3. Simplified99.9%

      \[\leadsto \color{blue}{x + y \cdot 0.002} \]
    4. Add Preprocessing
    5. Taylor expanded in x around inf 80.3%

      \[\leadsto \color{blue}{x} \]
  3. Recombined 2 regimes into one program.
  4. Final simplification81.1%

    \[\leadsto \begin{array}{l} \mathbf{if}\;\frac{y}{500} \leq -1 \cdot 10^{+80} \lor \neg \left(\frac{y}{500} \leq 10^{-16}\right):\\ \;\;\;\;\frac{y}{500}\\ \mathbf{else}:\\ \;\;\;\;x\\ \end{array} \]
  5. Add Preprocessing

Alternative 3: 74.5% accurate, 0.4× speedup?

\[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;y \leq -6.8 \cdot 10^{+71} \lor \neg \left(y \leq 1.02 \cdot 10^{-13}\right):\\ \;\;\;\;y \cdot 0.002\\ \mathbf{else}:\\ \;\;\;\;x\\ \end{array} \end{array} \]
(FPCore (x y)
 :precision binary64
 (if (or (<= y -6.8e+71) (not (<= y 1.02e-13))) (* y 0.002) x))
double code(double x, double y) {
	double tmp;
	if ((y <= -6.8e+71) || !(y <= 1.02e-13)) {
		tmp = y * 0.002;
	} 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 ((y <= (-6.8d+71)) .or. (.not. (y <= 1.02d-13))) then
        tmp = y * 0.002d0
    else
        tmp = x
    end if
    code = tmp
end function
public static double code(double x, double y) {
	double tmp;
	if ((y <= -6.8e+71) || !(y <= 1.02e-13)) {
		tmp = y * 0.002;
	} else {
		tmp = x;
	}
	return tmp;
}
def code(x, y):
	tmp = 0
	if (y <= -6.8e+71) or not (y <= 1.02e-13):
		tmp = y * 0.002
	else:
		tmp = x
	return tmp
function code(x, y)
	tmp = 0.0
	if ((y <= -6.8e+71) || !(y <= 1.02e-13))
		tmp = Float64(y * 0.002);
	else
		tmp = x;
	end
	return tmp
end
function tmp_2 = code(x, y)
	tmp = 0.0;
	if ((y <= -6.8e+71) || ~((y <= 1.02e-13)))
		tmp = y * 0.002;
	else
		tmp = x;
	end
	tmp_2 = tmp;
end
code[x_, y_] := If[Or[LessEqual[y, -6.8e+71], N[Not[LessEqual[y, 1.02e-13]], $MachinePrecision]], N[(y * 0.002), $MachinePrecision], x]
\begin{array}{l}

\\
\begin{array}{l}
\mathbf{if}\;y \leq -6.8 \cdot 10^{+71} \lor \neg \left(y \leq 1.02 \cdot 10^{-13}\right):\\
\;\;\;\;y \cdot 0.002\\

\mathbf{else}:\\
\;\;\;\;x\\


\end{array}
\end{array}
Derivation
  1. Split input into 2 regimes
  2. if y < -6.7999999999999997e71 or 1.0199999999999999e-13 < y

    1. Initial program 100.0%

      \[x + \frac{y}{500} \]
    2. Step-by-step derivation
      1. *-rgt-identity100.0%

        \[\leadsto x + \color{blue}{\frac{y}{500} \cdot 1} \]
      2. metadata-eval100.0%

        \[\leadsto x + \frac{y}{500} \cdot \color{blue}{\left(--1\right)} \]
      3. associate-*l/100.0%

        \[\leadsto x + \color{blue}{\frac{y \cdot \left(--1\right)}{500}} \]
      4. associate-/l*99.8%

        \[\leadsto x + \color{blue}{y \cdot \frac{--1}{500}} \]
      5. metadata-eval99.8%

        \[\leadsto x + y \cdot \frac{\color{blue}{1}}{500} \]
      6. metadata-eval99.8%

        \[\leadsto x + y \cdot \color{blue}{0.002} \]
    3. Simplified99.8%

      \[\leadsto \color{blue}{x + y \cdot 0.002} \]
    4. Add Preprocessing
    5. Taylor expanded in y around inf 99.7%

      \[\leadsto \color{blue}{y \cdot \left(0.002 + \frac{x}{y}\right)} \]
    6. Taylor expanded in x around 0 81.8%

      \[\leadsto y \cdot \color{blue}{0.002} \]

    if -6.7999999999999997e71 < y < 1.0199999999999999e-13

    1. Initial program 100.0%

      \[x + \frac{y}{500} \]
    2. Step-by-step derivation
      1. *-rgt-identity100.0%

        \[\leadsto x + \color{blue}{\frac{y}{500} \cdot 1} \]
      2. metadata-eval100.0%

        \[\leadsto x + \frac{y}{500} \cdot \color{blue}{\left(--1\right)} \]
      3. associate-*l/100.0%

        \[\leadsto x + \color{blue}{\frac{y \cdot \left(--1\right)}{500}} \]
      4. associate-/l*99.9%

        \[\leadsto x + \color{blue}{y \cdot \frac{--1}{500}} \]
      5. metadata-eval99.9%

        \[\leadsto x + y \cdot \frac{\color{blue}{1}}{500} \]
      6. metadata-eval99.9%

        \[\leadsto x + y \cdot \color{blue}{0.002} \]
    3. Simplified99.9%

      \[\leadsto \color{blue}{x + y \cdot 0.002} \]
    4. Add Preprocessing
    5. Taylor expanded in x around inf 80.3%

      \[\leadsto \color{blue}{x} \]
  3. Recombined 2 regimes into one program.
  4. Final simplification81.0%

    \[\leadsto \begin{array}{l} \mathbf{if}\;y \leq -6.8 \cdot 10^{+71} \lor \neg \left(y \leq 1.02 \cdot 10^{-13}\right):\\ \;\;\;\;y \cdot 0.002\\ \mathbf{else}:\\ \;\;\;\;x\\ \end{array} \]
  5. Add Preprocessing

Alternative 4: 99.9% accurate, 1.0× speedup?

\[\begin{array}{l} \\ x + y \cdot 0.002 \end{array} \]
(FPCore (x y) :precision binary64 (+ x (* y 0.002)))
double code(double x, double y) {
	return x + (y * 0.002);
}
real(8) function code(x, y)
    real(8), intent (in) :: x
    real(8), intent (in) :: y
    code = x + (y * 0.002d0)
end function
public static double code(double x, double y) {
	return x + (y * 0.002);
}
def code(x, y):
	return x + (y * 0.002)
function code(x, y)
	return Float64(x + Float64(y * 0.002))
end
function tmp = code(x, y)
	tmp = x + (y * 0.002);
end
code[x_, y_] := N[(x + N[(y * 0.002), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}

\\
x + y \cdot 0.002
\end{array}
Derivation
  1. Initial program 100.0%

    \[x + \frac{y}{500} \]
  2. Step-by-step derivation
    1. *-rgt-identity100.0%

      \[\leadsto x + \color{blue}{\frac{y}{500} \cdot 1} \]
    2. metadata-eval100.0%

      \[\leadsto x + \frac{y}{500} \cdot \color{blue}{\left(--1\right)} \]
    3. associate-*l/100.0%

      \[\leadsto x + \color{blue}{\frac{y \cdot \left(--1\right)}{500}} \]
    4. associate-/l*99.9%

      \[\leadsto x + \color{blue}{y \cdot \frac{--1}{500}} \]
    5. metadata-eval99.9%

      \[\leadsto x + y \cdot \frac{\color{blue}{1}}{500} \]
    6. metadata-eval99.9%

      \[\leadsto x + y \cdot \color{blue}{0.002} \]
  3. Simplified99.9%

    \[\leadsto \color{blue}{x + y \cdot 0.002} \]
  4. Add Preprocessing
  5. Add Preprocessing

Alternative 5: 50.9% accurate, 5.0× 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 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%

    \[x + \frac{y}{500} \]
  2. Step-by-step derivation
    1. *-rgt-identity100.0%

      \[\leadsto x + \color{blue}{\frac{y}{500} \cdot 1} \]
    2. metadata-eval100.0%

      \[\leadsto x + \frac{y}{500} \cdot \color{blue}{\left(--1\right)} \]
    3. associate-*l/100.0%

      \[\leadsto x + \color{blue}{\frac{y \cdot \left(--1\right)}{500}} \]
    4. associate-/l*99.9%

      \[\leadsto x + \color{blue}{y \cdot \frac{--1}{500}} \]
    5. metadata-eval99.9%

      \[\leadsto x + y \cdot \frac{\color{blue}{1}}{500} \]
    6. metadata-eval99.9%

      \[\leadsto x + y \cdot \color{blue}{0.002} \]
  3. Simplified99.9%

    \[\leadsto \color{blue}{x + y \cdot 0.002} \]
  4. Add Preprocessing
  5. Taylor expanded in x around inf 52.7%

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

Reproduce

?
herbie shell --seed 2024130 
(FPCore (x y)
  :name "Data.Colour.CIE:cieLAB from colour-2.3.3, C"
  :precision binary64
  (+ x (/ y 500.0)))