Data.Array.Repa.Algorithms.ColorRamp:rampColorHotToCold from repa-algorithms-3.4.0.1, C

Percentage Accurate: 99.9% → 99.9%
Time: 4.3s
Alternatives: 6
Speedup: 1.4×

Specification

?
\[\begin{array}{l} \\ 1 + \frac{4 \cdot \left(\left(x + y \cdot 0.25\right) - z\right)}{y} \end{array} \]
(FPCore (x y z)
 :precision binary64
 (+ 1.0 (/ (* 4.0 (- (+ x (* y 0.25)) z)) y)))
double code(double x, double y, double z) {
	return 1.0 + ((4.0 * ((x + (y * 0.25)) - z)) / y);
}
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 + ((4.0d0 * ((x + (y * 0.25d0)) - z)) / y)
end function
public static double code(double x, double y, double z) {
	return 1.0 + ((4.0 * ((x + (y * 0.25)) - z)) / y);
}
def code(x, y, z):
	return 1.0 + ((4.0 * ((x + (y * 0.25)) - z)) / y)
function code(x, y, z)
	return Float64(1.0 + Float64(Float64(4.0 * Float64(Float64(x + Float64(y * 0.25)) - z)) / y))
end
function tmp = code(x, y, z)
	tmp = 1.0 + ((4.0 * ((x + (y * 0.25)) - z)) / y);
end
code[x_, y_, z_] := N[(1.0 + N[(N[(4.0 * N[(N[(x + N[(y * 0.25), $MachinePrecision]), $MachinePrecision] - z), $MachinePrecision]), $MachinePrecision] / y), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}

\\
1 + \frac{4 \cdot \left(\left(x + y \cdot 0.25\right) - z\right)}{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: 99.9% accurate, 1.0× speedup?

\[\begin{array}{l} \\ 1 + \frac{4 \cdot \left(\left(x + y \cdot 0.25\right) - z\right)}{y} \end{array} \]
(FPCore (x y z)
 :precision binary64
 (+ 1.0 (/ (* 4.0 (- (+ x (* y 0.25)) z)) y)))
double code(double x, double y, double z) {
	return 1.0 + ((4.0 * ((x + (y * 0.25)) - z)) / y);
}
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 + ((4.0d0 * ((x + (y * 0.25d0)) - z)) / y)
end function
public static double code(double x, double y, double z) {
	return 1.0 + ((4.0 * ((x + (y * 0.25)) - z)) / y);
}
def code(x, y, z):
	return 1.0 + ((4.0 * ((x + (y * 0.25)) - z)) / y)
function code(x, y, z)
	return Float64(1.0 + Float64(Float64(4.0 * Float64(Float64(x + Float64(y * 0.25)) - z)) / y))
end
function tmp = code(x, y, z)
	tmp = 1.0 + ((4.0 * ((x + (y * 0.25)) - z)) / y);
end
code[x_, y_, z_] := N[(1.0 + N[(N[(4.0 * N[(N[(x + N[(y * 0.25), $MachinePrecision]), $MachinePrecision] - z), $MachinePrecision]), $MachinePrecision] / y), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}

\\
1 + \frac{4 \cdot \left(\left(x + y \cdot 0.25\right) - z\right)}{y}
\end{array}

Alternative 1: 99.9% accurate, 1.4× speedup?

\[\begin{array}{l} \\ \frac{4 \cdot \left(x - z\right)}{y} + 2 \end{array} \]
(FPCore (x y z) :precision binary64 (+ (/ (* 4.0 (- x z)) y) 2.0))
double code(double x, double y, double z) {
	return ((4.0 * (x - z)) / y) + 2.0;
}
real(8) function code(x, y, z)
    real(8), intent (in) :: x
    real(8), intent (in) :: y
    real(8), intent (in) :: z
    code = ((4.0d0 * (x - z)) / y) + 2.0d0
end function
public static double code(double x, double y, double z) {
	return ((4.0 * (x - z)) / y) + 2.0;
}
def code(x, y, z):
	return ((4.0 * (x - z)) / y) + 2.0
function code(x, y, z)
	return Float64(Float64(Float64(4.0 * Float64(x - z)) / y) + 2.0)
end
function tmp = code(x, y, z)
	tmp = ((4.0 * (x - z)) / y) + 2.0;
end
code[x_, y_, z_] := N[(N[(N[(4.0 * N[(x - z), $MachinePrecision]), $MachinePrecision] / y), $MachinePrecision] + 2.0), $MachinePrecision]
\begin{array}{l}

\\
\frac{4 \cdot \left(x - z\right)}{y} + 2
\end{array}
Derivation
  1. Initial program 100.0%

    \[1 + \frac{4 \cdot \left(\left(x + y \cdot 0.25\right) - z\right)}{y} \]
  2. Step-by-step derivation
    1. +-commutative100.0%

      \[\leadsto \color{blue}{\frac{4 \cdot \left(\left(x + y \cdot 0.25\right) - z\right)}{y} + 1} \]
    2. associate-*l/99.8%

      \[\leadsto \color{blue}{\frac{4}{y} \cdot \left(\left(x + y \cdot 0.25\right) - z\right)} + 1 \]
    3. +-commutative99.8%

      \[\leadsto \frac{4}{y} \cdot \left(\color{blue}{\left(y \cdot 0.25 + x\right)} - z\right) + 1 \]
    4. associate--l+99.8%

      \[\leadsto \frac{4}{y} \cdot \color{blue}{\left(y \cdot 0.25 + \left(x - z\right)\right)} + 1 \]
    5. +-commutative99.8%

      \[\leadsto \frac{4}{y} \cdot \color{blue}{\left(\left(x - z\right) + y \cdot 0.25\right)} + 1 \]
    6. distribute-lft-in99.8%

      \[\leadsto \color{blue}{\left(\frac{4}{y} \cdot \left(x - z\right) + \frac{4}{y} \cdot \left(y \cdot 0.25\right)\right)} + 1 \]
    7. associate-+l+99.8%

      \[\leadsto \color{blue}{\frac{4}{y} \cdot \left(x - z\right) + \left(\frac{4}{y} \cdot \left(y \cdot 0.25\right) + 1\right)} \]
    8. associate-*l/100.0%

      \[\leadsto \color{blue}{\frac{4 \cdot \left(x - z\right)}{y}} + \left(\frac{4}{y} \cdot \left(y \cdot 0.25\right) + 1\right) \]
    9. associate-*l/100.0%

      \[\leadsto \frac{4 \cdot \left(x - z\right)}{y} + \left(\color{blue}{\frac{4 \cdot \left(y \cdot 0.25\right)}{y}} + 1\right) \]
    10. *-commutative100.0%

      \[\leadsto \frac{4 \cdot \left(x - z\right)}{y} + \left(\frac{\color{blue}{\left(y \cdot 0.25\right) \cdot 4}}{y} + 1\right) \]
    11. associate-*l*100.0%

      \[\leadsto \frac{4 \cdot \left(x - z\right)}{y} + \left(\frac{\color{blue}{y \cdot \left(0.25 \cdot 4\right)}}{y} + 1\right) \]
    12. metadata-eval100.0%

      \[\leadsto \frac{4 \cdot \left(x - z\right)}{y} + \left(\frac{y \cdot \color{blue}{1}}{y} + 1\right) \]
    13. *-rgt-identity100.0%

      \[\leadsto \frac{4 \cdot \left(x - z\right)}{y} + \left(\frac{\color{blue}{y}}{y} + 1\right) \]
    14. *-inverses100.0%

      \[\leadsto \frac{4 \cdot \left(x - z\right)}{y} + \left(\color{blue}{1} + 1\right) \]
    15. metadata-eval100.0%

      \[\leadsto \frac{4 \cdot \left(x - z\right)}{y} + \color{blue}{2} \]
  3. Simplified100.0%

    \[\leadsto \color{blue}{\frac{4 \cdot \left(x - z\right)}{y} + 2} \]
  4. Add Preprocessing
  5. Add Preprocessing

Alternative 2: 85.2% accurate, 0.8× speedup?

\[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;x \leq -1250000000 \lor \neg \left(x \leq 1.25 \cdot 10^{-68}\right):\\ \;\;\;\;2 + 4 \cdot \frac{x}{y}\\ \mathbf{else}:\\ \;\;\;\;2 + -4 \cdot \frac{z}{y}\\ \end{array} \end{array} \]
(FPCore (x y z)
 :precision binary64
 (if (or (<= x -1250000000.0) (not (<= x 1.25e-68)))
   (+ 2.0 (* 4.0 (/ x y)))
   (+ 2.0 (* -4.0 (/ z y)))))
double code(double x, double y, double z) {
	double tmp;
	if ((x <= -1250000000.0) || !(x <= 1.25e-68)) {
		tmp = 2.0 + (4.0 * (x / y));
	} else {
		tmp = 2.0 + (-4.0 * (z / y));
	}
	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 ((x <= (-1250000000.0d0)) .or. (.not. (x <= 1.25d-68))) then
        tmp = 2.0d0 + (4.0d0 * (x / y))
    else
        tmp = 2.0d0 + ((-4.0d0) * (z / y))
    end if
    code = tmp
end function
public static double code(double x, double y, double z) {
	double tmp;
	if ((x <= -1250000000.0) || !(x <= 1.25e-68)) {
		tmp = 2.0 + (4.0 * (x / y));
	} else {
		tmp = 2.0 + (-4.0 * (z / y));
	}
	return tmp;
}
def code(x, y, z):
	tmp = 0
	if (x <= -1250000000.0) or not (x <= 1.25e-68):
		tmp = 2.0 + (4.0 * (x / y))
	else:
		tmp = 2.0 + (-4.0 * (z / y))
	return tmp
function code(x, y, z)
	tmp = 0.0
	if ((x <= -1250000000.0) || !(x <= 1.25e-68))
		tmp = Float64(2.0 + Float64(4.0 * Float64(x / y)));
	else
		tmp = Float64(2.0 + Float64(-4.0 * Float64(z / y)));
	end
	return tmp
end
function tmp_2 = code(x, y, z)
	tmp = 0.0;
	if ((x <= -1250000000.0) || ~((x <= 1.25e-68)))
		tmp = 2.0 + (4.0 * (x / y));
	else
		tmp = 2.0 + (-4.0 * (z / y));
	end
	tmp_2 = tmp;
end
code[x_, y_, z_] := If[Or[LessEqual[x, -1250000000.0], N[Not[LessEqual[x, 1.25e-68]], $MachinePrecision]], N[(2.0 + N[(4.0 * N[(x / y), $MachinePrecision]), $MachinePrecision]), $MachinePrecision], N[(2.0 + N[(-4.0 * N[(z / y), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]]
\begin{array}{l}

\\
\begin{array}{l}
\mathbf{if}\;x \leq -1250000000 \lor \neg \left(x \leq 1.25 \cdot 10^{-68}\right):\\
\;\;\;\;2 + 4 \cdot \frac{x}{y}\\

\mathbf{else}:\\
\;\;\;\;2 + -4 \cdot \frac{z}{y}\\


\end{array}
\end{array}
Derivation
  1. Split input into 2 regimes
  2. if x < -1.25e9 or 1.24999999999999993e-68 < x

    1. Initial program 100.0%

      \[1 + \frac{4 \cdot \left(\left(x + y \cdot 0.25\right) - z\right)}{y} \]
    2. Step-by-step derivation
      1. +-commutative100.0%

        \[\leadsto \color{blue}{\frac{4 \cdot \left(\left(x + y \cdot 0.25\right) - z\right)}{y} + 1} \]
      2. associate-*l/99.7%

        \[\leadsto \color{blue}{\frac{4}{y} \cdot \left(\left(x + y \cdot 0.25\right) - z\right)} + 1 \]
      3. +-commutative99.7%

        \[\leadsto \frac{4}{y} \cdot \left(\color{blue}{\left(y \cdot 0.25 + x\right)} - z\right) + 1 \]
      4. associate--l+99.7%

        \[\leadsto \frac{4}{y} \cdot \color{blue}{\left(y \cdot 0.25 + \left(x - z\right)\right)} + 1 \]
      5. +-commutative99.7%

        \[\leadsto \frac{4}{y} \cdot \color{blue}{\left(\left(x - z\right) + y \cdot 0.25\right)} + 1 \]
      6. distribute-lft-in99.7%

        \[\leadsto \color{blue}{\left(\frac{4}{y} \cdot \left(x - z\right) + \frac{4}{y} \cdot \left(y \cdot 0.25\right)\right)} + 1 \]
      7. associate-+l+99.7%

        \[\leadsto \color{blue}{\frac{4}{y} \cdot \left(x - z\right) + \left(\frac{4}{y} \cdot \left(y \cdot 0.25\right) + 1\right)} \]
      8. associate-*l/100.0%

        \[\leadsto \color{blue}{\frac{4 \cdot \left(x - z\right)}{y}} + \left(\frac{4}{y} \cdot \left(y \cdot 0.25\right) + 1\right) \]
      9. associate-*l/100.0%

        \[\leadsto \frac{4 \cdot \left(x - z\right)}{y} + \left(\color{blue}{\frac{4 \cdot \left(y \cdot 0.25\right)}{y}} + 1\right) \]
      10. *-commutative100.0%

        \[\leadsto \frac{4 \cdot \left(x - z\right)}{y} + \left(\frac{\color{blue}{\left(y \cdot 0.25\right) \cdot 4}}{y} + 1\right) \]
      11. associate-*l*100.0%

        \[\leadsto \frac{4 \cdot \left(x - z\right)}{y} + \left(\frac{\color{blue}{y \cdot \left(0.25 \cdot 4\right)}}{y} + 1\right) \]
      12. metadata-eval100.0%

        \[\leadsto \frac{4 \cdot \left(x - z\right)}{y} + \left(\frac{y \cdot \color{blue}{1}}{y} + 1\right) \]
      13. *-rgt-identity100.0%

        \[\leadsto \frac{4 \cdot \left(x - z\right)}{y} + \left(\frac{\color{blue}{y}}{y} + 1\right) \]
      14. *-inverses100.0%

        \[\leadsto \frac{4 \cdot \left(x - z\right)}{y} + \left(\color{blue}{1} + 1\right) \]
      15. metadata-eval100.0%

        \[\leadsto \frac{4 \cdot \left(x - z\right)}{y} + \color{blue}{2} \]
    3. Simplified100.0%

      \[\leadsto \color{blue}{\frac{4 \cdot \left(x - z\right)}{y} + 2} \]
    4. Add Preprocessing
    5. Taylor expanded in x around inf 84.0%

      \[\leadsto \color{blue}{4 \cdot \frac{x}{y}} + 2 \]

    if -1.25e9 < x < 1.24999999999999993e-68

    1. Initial program 99.9%

      \[1 + \frac{4 \cdot \left(\left(x + y \cdot 0.25\right) - z\right)}{y} \]
    2. Step-by-step derivation
      1. +-commutative99.9%

        \[\leadsto \color{blue}{\frac{4 \cdot \left(\left(x + y \cdot 0.25\right) - z\right)}{y} + 1} \]
      2. associate-*l/99.8%

        \[\leadsto \color{blue}{\frac{4}{y} \cdot \left(\left(x + y \cdot 0.25\right) - z\right)} + 1 \]
      3. +-commutative99.8%

        \[\leadsto \frac{4}{y} \cdot \left(\color{blue}{\left(y \cdot 0.25 + x\right)} - z\right) + 1 \]
      4. associate--l+99.8%

        \[\leadsto \frac{4}{y} \cdot \color{blue}{\left(y \cdot 0.25 + \left(x - z\right)\right)} + 1 \]
      5. +-commutative99.8%

        \[\leadsto \frac{4}{y} \cdot \color{blue}{\left(\left(x - z\right) + y \cdot 0.25\right)} + 1 \]
      6. distribute-lft-in99.8%

        \[\leadsto \color{blue}{\left(\frac{4}{y} \cdot \left(x - z\right) + \frac{4}{y} \cdot \left(y \cdot 0.25\right)\right)} + 1 \]
      7. associate-+l+99.9%

        \[\leadsto \color{blue}{\frac{4}{y} \cdot \left(x - z\right) + \left(\frac{4}{y} \cdot \left(y \cdot 0.25\right) + 1\right)} \]
      8. associate-*l/100.0%

        \[\leadsto \color{blue}{\frac{4 \cdot \left(x - z\right)}{y}} + \left(\frac{4}{y} \cdot \left(y \cdot 0.25\right) + 1\right) \]
      9. associate-*l/100.0%

        \[\leadsto \frac{4 \cdot \left(x - z\right)}{y} + \left(\color{blue}{\frac{4 \cdot \left(y \cdot 0.25\right)}{y}} + 1\right) \]
      10. *-commutative100.0%

        \[\leadsto \frac{4 \cdot \left(x - z\right)}{y} + \left(\frac{\color{blue}{\left(y \cdot 0.25\right) \cdot 4}}{y} + 1\right) \]
      11. associate-*l*100.0%

        \[\leadsto \frac{4 \cdot \left(x - z\right)}{y} + \left(\frac{\color{blue}{y \cdot \left(0.25 \cdot 4\right)}}{y} + 1\right) \]
      12. metadata-eval100.0%

        \[\leadsto \frac{4 \cdot \left(x - z\right)}{y} + \left(\frac{y \cdot \color{blue}{1}}{y} + 1\right) \]
      13. *-rgt-identity100.0%

        \[\leadsto \frac{4 \cdot \left(x - z\right)}{y} + \left(\frac{\color{blue}{y}}{y} + 1\right) \]
      14. *-inverses100.0%

        \[\leadsto \frac{4 \cdot \left(x - z\right)}{y} + \left(\color{blue}{1} + 1\right) \]
      15. metadata-eval100.0%

        \[\leadsto \frac{4 \cdot \left(x - z\right)}{y} + \color{blue}{2} \]
    3. Simplified100.0%

      \[\leadsto \color{blue}{\frac{4 \cdot \left(x - z\right)}{y} + 2} \]
    4. Add Preprocessing
    5. Taylor expanded in x around 0 93.4%

      \[\leadsto \color{blue}{-4 \cdot \frac{z}{y}} + 2 \]
  3. Recombined 2 regimes into one program.
  4. Final simplification88.3%

    \[\leadsto \begin{array}{l} \mathbf{if}\;x \leq -1250000000 \lor \neg \left(x \leq 1.25 \cdot 10^{-68}\right):\\ \;\;\;\;2 + 4 \cdot \frac{x}{y}\\ \mathbf{else}:\\ \;\;\;\;2 + -4 \cdot \frac{z}{y}\\ \end{array} \]
  5. Add Preprocessing

Alternative 3: 54.3% accurate, 0.9× speedup?

\[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;y \leq -4300000000000:\\ \;\;\;\;2\\ \mathbf{elif}\;y \leq 4.1 \cdot 10^{+85}:\\ \;\;\;\;-4 \cdot \frac{z}{y}\\ \mathbf{else}:\\ \;\;\;\;2\\ \end{array} \end{array} \]
(FPCore (x y z)
 :precision binary64
 (if (<= y -4300000000000.0) 2.0 (if (<= y 4.1e+85) (* -4.0 (/ z y)) 2.0)))
double code(double x, double y, double z) {
	double tmp;
	if (y <= -4300000000000.0) {
		tmp = 2.0;
	} else if (y <= 4.1e+85) {
		tmp = -4.0 * (z / y);
	} else {
		tmp = 2.0;
	}
	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 (y <= (-4300000000000.0d0)) then
        tmp = 2.0d0
    else if (y <= 4.1d+85) then
        tmp = (-4.0d0) * (z / y)
    else
        tmp = 2.0d0
    end if
    code = tmp
end function
public static double code(double x, double y, double z) {
	double tmp;
	if (y <= -4300000000000.0) {
		tmp = 2.0;
	} else if (y <= 4.1e+85) {
		tmp = -4.0 * (z / y);
	} else {
		tmp = 2.0;
	}
	return tmp;
}
def code(x, y, z):
	tmp = 0
	if y <= -4300000000000.0:
		tmp = 2.0
	elif y <= 4.1e+85:
		tmp = -4.0 * (z / y)
	else:
		tmp = 2.0
	return tmp
function code(x, y, z)
	tmp = 0.0
	if (y <= -4300000000000.0)
		tmp = 2.0;
	elseif (y <= 4.1e+85)
		tmp = Float64(-4.0 * Float64(z / y));
	else
		tmp = 2.0;
	end
	return tmp
end
function tmp_2 = code(x, y, z)
	tmp = 0.0;
	if (y <= -4300000000000.0)
		tmp = 2.0;
	elseif (y <= 4.1e+85)
		tmp = -4.0 * (z / y);
	else
		tmp = 2.0;
	end
	tmp_2 = tmp;
end
code[x_, y_, z_] := If[LessEqual[y, -4300000000000.0], 2.0, If[LessEqual[y, 4.1e+85], N[(-4.0 * N[(z / y), $MachinePrecision]), $MachinePrecision], 2.0]]
\begin{array}{l}

\\
\begin{array}{l}
\mathbf{if}\;y \leq -4300000000000:\\
\;\;\;\;2\\

\mathbf{elif}\;y \leq 4.1 \cdot 10^{+85}:\\
\;\;\;\;-4 \cdot \frac{z}{y}\\

\mathbf{else}:\\
\;\;\;\;2\\


\end{array}
\end{array}
Derivation
  1. Split input into 2 regimes
  2. if y < -4.3e12 or 4.09999999999999978e85 < y

    1. Initial program 99.9%

      \[1 + \frac{4 \cdot \left(\left(x + y \cdot 0.25\right) - z\right)}{y} \]
    2. Step-by-step derivation
      1. +-commutative99.9%

        \[\leadsto \color{blue}{\frac{4 \cdot \left(\left(x + y \cdot 0.25\right) - z\right)}{y} + 1} \]
      2. associate-*l/99.8%

        \[\leadsto \color{blue}{\frac{4}{y} \cdot \left(\left(x + y \cdot 0.25\right) - z\right)} + 1 \]
      3. +-commutative99.8%

        \[\leadsto \frac{4}{y} \cdot \left(\color{blue}{\left(y \cdot 0.25 + x\right)} - z\right) + 1 \]
      4. associate--l+99.8%

        \[\leadsto \frac{4}{y} \cdot \color{blue}{\left(y \cdot 0.25 + \left(x - z\right)\right)} + 1 \]
      5. +-commutative99.8%

        \[\leadsto \frac{4}{y} \cdot \color{blue}{\left(\left(x - z\right) + y \cdot 0.25\right)} + 1 \]
      6. distribute-lft-in99.8%

        \[\leadsto \color{blue}{\left(\frac{4}{y} \cdot \left(x - z\right) + \frac{4}{y} \cdot \left(y \cdot 0.25\right)\right)} + 1 \]
      7. associate-+l+99.8%

        \[\leadsto \color{blue}{\frac{4}{y} \cdot \left(x - z\right) + \left(\frac{4}{y} \cdot \left(y \cdot 0.25\right) + 1\right)} \]
      8. associate-*l/100.0%

        \[\leadsto \color{blue}{\frac{4 \cdot \left(x - z\right)}{y}} + \left(\frac{4}{y} \cdot \left(y \cdot 0.25\right) + 1\right) \]
      9. associate-*l/100.0%

        \[\leadsto \frac{4 \cdot \left(x - z\right)}{y} + \left(\color{blue}{\frac{4 \cdot \left(y \cdot 0.25\right)}{y}} + 1\right) \]
      10. *-commutative100.0%

        \[\leadsto \frac{4 \cdot \left(x - z\right)}{y} + \left(\frac{\color{blue}{\left(y \cdot 0.25\right) \cdot 4}}{y} + 1\right) \]
      11. associate-*l*100.0%

        \[\leadsto \frac{4 \cdot \left(x - z\right)}{y} + \left(\frac{\color{blue}{y \cdot \left(0.25 \cdot 4\right)}}{y} + 1\right) \]
      12. metadata-eval100.0%

        \[\leadsto \frac{4 \cdot \left(x - z\right)}{y} + \left(\frac{y \cdot \color{blue}{1}}{y} + 1\right) \]
      13. *-rgt-identity100.0%

        \[\leadsto \frac{4 \cdot \left(x - z\right)}{y} + \left(\frac{\color{blue}{y}}{y} + 1\right) \]
      14. *-inverses100.0%

        \[\leadsto \frac{4 \cdot \left(x - z\right)}{y} + \left(\color{blue}{1} + 1\right) \]
      15. metadata-eval100.0%

        \[\leadsto \frac{4 \cdot \left(x - z\right)}{y} + \color{blue}{2} \]
    3. Simplified100.0%

      \[\leadsto \color{blue}{\frac{4 \cdot \left(x - z\right)}{y} + 2} \]
    4. Add Preprocessing
    5. Taylor expanded in x around 0 81.8%

      \[\leadsto \color{blue}{-4 \cdot \frac{z}{y}} + 2 \]
    6. Taylor expanded in z around 0 65.4%

      \[\leadsto \color{blue}{2} \]

    if -4.3e12 < y < 4.09999999999999978e85

    1. Initial program 100.0%

      \[1 + \frac{4 \cdot \left(\left(x + y \cdot 0.25\right) - z\right)}{y} \]
    2. Step-by-step derivation
      1. +-commutative100.0%

        \[\leadsto \color{blue}{\frac{4 \cdot \left(\left(x + y \cdot 0.25\right) - z\right)}{y} + 1} \]
      2. associate-*l/99.8%

        \[\leadsto \color{blue}{\frac{4}{y} \cdot \left(\left(x + y \cdot 0.25\right) - z\right)} + 1 \]
      3. +-commutative99.8%

        \[\leadsto \frac{4}{y} \cdot \left(\color{blue}{\left(y \cdot 0.25 + x\right)} - z\right) + 1 \]
      4. associate--l+99.8%

        \[\leadsto \frac{4}{y} \cdot \color{blue}{\left(y \cdot 0.25 + \left(x - z\right)\right)} + 1 \]
      5. +-commutative99.8%

        \[\leadsto \frac{4}{y} \cdot \color{blue}{\left(\left(x - z\right) + y \cdot 0.25\right)} + 1 \]
      6. distribute-lft-in99.8%

        \[\leadsto \color{blue}{\left(\frac{4}{y} \cdot \left(x - z\right) + \frac{4}{y} \cdot \left(y \cdot 0.25\right)\right)} + 1 \]
      7. associate-+l+99.8%

        \[\leadsto \color{blue}{\frac{4}{y} \cdot \left(x - z\right) + \left(\frac{4}{y} \cdot \left(y \cdot 0.25\right) + 1\right)} \]
      8. associate-*l/100.0%

        \[\leadsto \color{blue}{\frac{4 \cdot \left(x - z\right)}{y}} + \left(\frac{4}{y} \cdot \left(y \cdot 0.25\right) + 1\right) \]
      9. associate-*l/100.0%

        \[\leadsto \frac{4 \cdot \left(x - z\right)}{y} + \left(\color{blue}{\frac{4 \cdot \left(y \cdot 0.25\right)}{y}} + 1\right) \]
      10. *-commutative100.0%

        \[\leadsto \frac{4 \cdot \left(x - z\right)}{y} + \left(\frac{\color{blue}{\left(y \cdot 0.25\right) \cdot 4}}{y} + 1\right) \]
      11. associate-*l*100.0%

        \[\leadsto \frac{4 \cdot \left(x - z\right)}{y} + \left(\frac{\color{blue}{y \cdot \left(0.25 \cdot 4\right)}}{y} + 1\right) \]
      12. metadata-eval100.0%

        \[\leadsto \frac{4 \cdot \left(x - z\right)}{y} + \left(\frac{y \cdot \color{blue}{1}}{y} + 1\right) \]
      13. *-rgt-identity100.0%

        \[\leadsto \frac{4 \cdot \left(x - z\right)}{y} + \left(\frac{\color{blue}{y}}{y} + 1\right) \]
      14. *-inverses100.0%

        \[\leadsto \frac{4 \cdot \left(x - z\right)}{y} + \left(\color{blue}{1} + 1\right) \]
      15. metadata-eval100.0%

        \[\leadsto \frac{4 \cdot \left(x - z\right)}{y} + \color{blue}{2} \]
    3. Simplified100.0%

      \[\leadsto \color{blue}{\frac{4 \cdot \left(x - z\right)}{y} + 2} \]
    4. Add Preprocessing
    5. Taylor expanded in x around 0 53.6%

      \[\leadsto \color{blue}{-4 \cdot \frac{z}{y}} + 2 \]
    6. Taylor expanded in z around inf 47.5%

      \[\leadsto \color{blue}{-4 \cdot \frac{z}{y}} \]
  3. Recombined 2 regimes into one program.
  4. Add Preprocessing

Alternative 4: 99.8% accurate, 1.4× speedup?

\[\begin{array}{l} \\ 2 + \left(x - z\right) \cdot \frac{4}{y} \end{array} \]
(FPCore (x y z) :precision binary64 (+ 2.0 (* (- x z) (/ 4.0 y))))
double code(double x, double y, double z) {
	return 2.0 + ((x - z) * (4.0 / y));
}
real(8) function code(x, y, z)
    real(8), intent (in) :: x
    real(8), intent (in) :: y
    real(8), intent (in) :: z
    code = 2.0d0 + ((x - z) * (4.0d0 / y))
end function
public static double code(double x, double y, double z) {
	return 2.0 + ((x - z) * (4.0 / y));
}
def code(x, y, z):
	return 2.0 + ((x - z) * (4.0 / y))
function code(x, y, z)
	return Float64(2.0 + Float64(Float64(x - z) * Float64(4.0 / y)))
end
function tmp = code(x, y, z)
	tmp = 2.0 + ((x - z) * (4.0 / y));
end
code[x_, y_, z_] := N[(2.0 + N[(N[(x - z), $MachinePrecision] * N[(4.0 / y), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}

\\
2 + \left(x - z\right) \cdot \frac{4}{y}
\end{array}
Derivation
  1. Initial program 100.0%

    \[1 + \frac{4 \cdot \left(\left(x + y \cdot 0.25\right) - z\right)}{y} \]
  2. Step-by-step derivation
    1. +-commutative100.0%

      \[\leadsto \color{blue}{\frac{4 \cdot \left(\left(x + y \cdot 0.25\right) - z\right)}{y} + 1} \]
    2. associate-*l/99.8%

      \[\leadsto \color{blue}{\frac{4}{y} \cdot \left(\left(x + y \cdot 0.25\right) - z\right)} + 1 \]
    3. +-commutative99.8%

      \[\leadsto \frac{4}{y} \cdot \left(\color{blue}{\left(y \cdot 0.25 + x\right)} - z\right) + 1 \]
    4. associate--l+99.8%

      \[\leadsto \frac{4}{y} \cdot \color{blue}{\left(y \cdot 0.25 + \left(x - z\right)\right)} + 1 \]
    5. +-commutative99.8%

      \[\leadsto \frac{4}{y} \cdot \color{blue}{\left(\left(x - z\right) + y \cdot 0.25\right)} + 1 \]
    6. distribute-lft-in99.8%

      \[\leadsto \color{blue}{\left(\frac{4}{y} \cdot \left(x - z\right) + \frac{4}{y} \cdot \left(y \cdot 0.25\right)\right)} + 1 \]
    7. associate-+l+99.8%

      \[\leadsto \color{blue}{\frac{4}{y} \cdot \left(x - z\right) + \left(\frac{4}{y} \cdot \left(y \cdot 0.25\right) + 1\right)} \]
    8. associate-*l/100.0%

      \[\leadsto \color{blue}{\frac{4 \cdot \left(x - z\right)}{y}} + \left(\frac{4}{y} \cdot \left(y \cdot 0.25\right) + 1\right) \]
    9. associate-*l/100.0%

      \[\leadsto \frac{4 \cdot \left(x - z\right)}{y} + \left(\color{blue}{\frac{4 \cdot \left(y \cdot 0.25\right)}{y}} + 1\right) \]
    10. *-commutative100.0%

      \[\leadsto \frac{4 \cdot \left(x - z\right)}{y} + \left(\frac{\color{blue}{\left(y \cdot 0.25\right) \cdot 4}}{y} + 1\right) \]
    11. associate-*l*100.0%

      \[\leadsto \frac{4 \cdot \left(x - z\right)}{y} + \left(\frac{\color{blue}{y \cdot \left(0.25 \cdot 4\right)}}{y} + 1\right) \]
    12. metadata-eval100.0%

      \[\leadsto \frac{4 \cdot \left(x - z\right)}{y} + \left(\frac{y \cdot \color{blue}{1}}{y} + 1\right) \]
    13. *-rgt-identity100.0%

      \[\leadsto \frac{4 \cdot \left(x - z\right)}{y} + \left(\frac{\color{blue}{y}}{y} + 1\right) \]
    14. *-inverses100.0%

      \[\leadsto \frac{4 \cdot \left(x - z\right)}{y} + \left(\color{blue}{1} + 1\right) \]
    15. metadata-eval100.0%

      \[\leadsto \frac{4 \cdot \left(x - z\right)}{y} + \color{blue}{2} \]
  3. Simplified100.0%

    \[\leadsto \color{blue}{\frac{4 \cdot \left(x - z\right)}{y} + 2} \]
  4. Add Preprocessing
  5. Taylor expanded in x around 0 97.3%

    \[\leadsto \color{blue}{\left(-4 \cdot \frac{z}{y} + 4 \cdot \frac{x}{y}\right)} + 2 \]
  6. Step-by-step derivation
    1. *-commutative97.3%

      \[\leadsto \left(\color{blue}{\frac{z}{y} \cdot -4} + 4 \cdot \frac{x}{y}\right) + 2 \]
    2. associate-*l/97.3%

      \[\leadsto \left(\color{blue}{\frac{z \cdot -4}{y}} + 4 \cdot \frac{x}{y}\right) + 2 \]
    3. associate-*r/97.2%

      \[\leadsto \left(\color{blue}{z \cdot \frac{-4}{y}} + 4 \cdot \frac{x}{y}\right) + 2 \]
    4. metadata-eval97.2%

      \[\leadsto \left(z \cdot \frac{\color{blue}{-4}}{y} + 4 \cdot \frac{x}{y}\right) + 2 \]
    5. distribute-neg-frac97.2%

      \[\leadsto \left(z \cdot \color{blue}{\left(-\frac{4}{y}\right)} + 4 \cdot \frac{x}{y}\right) + 2 \]
    6. metadata-eval97.2%

      \[\leadsto \left(z \cdot \left(-\frac{\color{blue}{4 \cdot 1}}{y}\right) + 4 \cdot \frac{x}{y}\right) + 2 \]
    7. associate-*r/97.2%

      \[\leadsto \left(z \cdot \left(-\color{blue}{4 \cdot \frac{1}{y}}\right) + 4 \cdot \frac{x}{y}\right) + 2 \]
    8. distribute-rgt-neg-in97.2%

      \[\leadsto \left(\color{blue}{\left(-z \cdot \left(4 \cdot \frac{1}{y}\right)\right)} + 4 \cdot \frac{x}{y}\right) + 2 \]
    9. *-commutative97.2%

      \[\leadsto \left(\left(-\color{blue}{\left(4 \cdot \frac{1}{y}\right) \cdot z}\right) + 4 \cdot \frac{x}{y}\right) + 2 \]
    10. distribute-rgt-neg-in97.2%

      \[\leadsto \left(\color{blue}{\left(4 \cdot \frac{1}{y}\right) \cdot \left(-z\right)} + 4 \cdot \frac{x}{y}\right) + 2 \]
    11. associate-*r/97.2%

      \[\leadsto \left(\left(4 \cdot \frac{1}{y}\right) \cdot \left(-z\right) + \color{blue}{\frac{4 \cdot x}{y}}\right) + 2 \]
    12. associate-*l/97.1%

      \[\leadsto \left(\left(4 \cdot \frac{1}{y}\right) \cdot \left(-z\right) + \color{blue}{\frac{4}{y} \cdot x}\right) + 2 \]
    13. metadata-eval97.1%

      \[\leadsto \left(\left(4 \cdot \frac{1}{y}\right) \cdot \left(-z\right) + \frac{\color{blue}{4 \cdot 1}}{y} \cdot x\right) + 2 \]
    14. associate-*r/97.1%

      \[\leadsto \left(\left(4 \cdot \frac{1}{y}\right) \cdot \left(-z\right) + \color{blue}{\left(4 \cdot \frac{1}{y}\right)} \cdot x\right) + 2 \]
    15. distribute-lft-in99.8%

      \[\leadsto \color{blue}{\left(4 \cdot \frac{1}{y}\right) \cdot \left(\left(-z\right) + x\right)} + 2 \]
    16. +-commutative99.8%

      \[\leadsto \left(4 \cdot \frac{1}{y}\right) \cdot \color{blue}{\left(x + \left(-z\right)\right)} + 2 \]
    17. sub-neg99.8%

      \[\leadsto \left(4 \cdot \frac{1}{y}\right) \cdot \color{blue}{\left(x - z\right)} + 2 \]
    18. associate-*r/99.8%

      \[\leadsto \color{blue}{\frac{4 \cdot 1}{y}} \cdot \left(x - z\right) + 2 \]
    19. metadata-eval99.8%

      \[\leadsto \frac{\color{blue}{4}}{y} \cdot \left(x - z\right) + 2 \]
  7. Simplified99.8%

    \[\leadsto \color{blue}{\frac{4}{y} \cdot \left(x - z\right)} + 2 \]
  8. Final simplification99.8%

    \[\leadsto 2 + \left(x - z\right) \cdot \frac{4}{y} \]
  9. Add Preprocessing

Alternative 5: 68.8% accurate, 1.9× speedup?

\[\begin{array}{l} \\ 2 + -4 \cdot \frac{z}{y} \end{array} \]
(FPCore (x y z) :precision binary64 (+ 2.0 (* -4.0 (/ z y))))
double code(double x, double y, double z) {
	return 2.0 + (-4.0 * (z / y));
}
real(8) function code(x, y, z)
    real(8), intent (in) :: x
    real(8), intent (in) :: y
    real(8), intent (in) :: z
    code = 2.0d0 + ((-4.0d0) * (z / y))
end function
public static double code(double x, double y, double z) {
	return 2.0 + (-4.0 * (z / y));
}
def code(x, y, z):
	return 2.0 + (-4.0 * (z / y))
function code(x, y, z)
	return Float64(2.0 + Float64(-4.0 * Float64(z / y)))
end
function tmp = code(x, y, z)
	tmp = 2.0 + (-4.0 * (z / y));
end
code[x_, y_, z_] := N[(2.0 + N[(-4.0 * N[(z / y), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}

\\
2 + -4 \cdot \frac{z}{y}
\end{array}
Derivation
  1. Initial program 100.0%

    \[1 + \frac{4 \cdot \left(\left(x + y \cdot 0.25\right) - z\right)}{y} \]
  2. Step-by-step derivation
    1. +-commutative100.0%

      \[\leadsto \color{blue}{\frac{4 \cdot \left(\left(x + y \cdot 0.25\right) - z\right)}{y} + 1} \]
    2. associate-*l/99.8%

      \[\leadsto \color{blue}{\frac{4}{y} \cdot \left(\left(x + y \cdot 0.25\right) - z\right)} + 1 \]
    3. +-commutative99.8%

      \[\leadsto \frac{4}{y} \cdot \left(\color{blue}{\left(y \cdot 0.25 + x\right)} - z\right) + 1 \]
    4. associate--l+99.8%

      \[\leadsto \frac{4}{y} \cdot \color{blue}{\left(y \cdot 0.25 + \left(x - z\right)\right)} + 1 \]
    5. +-commutative99.8%

      \[\leadsto \frac{4}{y} \cdot \color{blue}{\left(\left(x - z\right) + y \cdot 0.25\right)} + 1 \]
    6. distribute-lft-in99.8%

      \[\leadsto \color{blue}{\left(\frac{4}{y} \cdot \left(x - z\right) + \frac{4}{y} \cdot \left(y \cdot 0.25\right)\right)} + 1 \]
    7. associate-+l+99.8%

      \[\leadsto \color{blue}{\frac{4}{y} \cdot \left(x - z\right) + \left(\frac{4}{y} \cdot \left(y \cdot 0.25\right) + 1\right)} \]
    8. associate-*l/100.0%

      \[\leadsto \color{blue}{\frac{4 \cdot \left(x - z\right)}{y}} + \left(\frac{4}{y} \cdot \left(y \cdot 0.25\right) + 1\right) \]
    9. associate-*l/100.0%

      \[\leadsto \frac{4 \cdot \left(x - z\right)}{y} + \left(\color{blue}{\frac{4 \cdot \left(y \cdot 0.25\right)}{y}} + 1\right) \]
    10. *-commutative100.0%

      \[\leadsto \frac{4 \cdot \left(x - z\right)}{y} + \left(\frac{\color{blue}{\left(y \cdot 0.25\right) \cdot 4}}{y} + 1\right) \]
    11. associate-*l*100.0%

      \[\leadsto \frac{4 \cdot \left(x - z\right)}{y} + \left(\frac{\color{blue}{y \cdot \left(0.25 \cdot 4\right)}}{y} + 1\right) \]
    12. metadata-eval100.0%

      \[\leadsto \frac{4 \cdot \left(x - z\right)}{y} + \left(\frac{y \cdot \color{blue}{1}}{y} + 1\right) \]
    13. *-rgt-identity100.0%

      \[\leadsto \frac{4 \cdot \left(x - z\right)}{y} + \left(\frac{\color{blue}{y}}{y} + 1\right) \]
    14. *-inverses100.0%

      \[\leadsto \frac{4 \cdot \left(x - z\right)}{y} + \left(\color{blue}{1} + 1\right) \]
    15. metadata-eval100.0%

      \[\leadsto \frac{4 \cdot \left(x - z\right)}{y} + \color{blue}{2} \]
  3. Simplified100.0%

    \[\leadsto \color{blue}{\frac{4 \cdot \left(x - z\right)}{y} + 2} \]
  4. Add Preprocessing
  5. Taylor expanded in x around 0 64.7%

    \[\leadsto \color{blue}{-4 \cdot \frac{z}{y}} + 2 \]
  6. Final simplification64.7%

    \[\leadsto 2 + -4 \cdot \frac{z}{y} \]
  7. Add Preprocessing

Alternative 6: 35.2% accurate, 13.0× speedup?

\[\begin{array}{l} \\ 2 \end{array} \]
(FPCore (x y z) :precision binary64 2.0)
double code(double x, double y, double z) {
	return 2.0;
}
real(8) function code(x, y, z)
    real(8), intent (in) :: x
    real(8), intent (in) :: y
    real(8), intent (in) :: z
    code = 2.0d0
end function
public static double code(double x, double y, double z) {
	return 2.0;
}
def code(x, y, z):
	return 2.0
function code(x, y, z)
	return 2.0
end
function tmp = code(x, y, z)
	tmp = 2.0;
end
code[x_, y_, z_] := 2.0
\begin{array}{l}

\\
2
\end{array}
Derivation
  1. Initial program 100.0%

    \[1 + \frac{4 \cdot \left(\left(x + y \cdot 0.25\right) - z\right)}{y} \]
  2. Step-by-step derivation
    1. +-commutative100.0%

      \[\leadsto \color{blue}{\frac{4 \cdot \left(\left(x + y \cdot 0.25\right) - z\right)}{y} + 1} \]
    2. associate-*l/99.8%

      \[\leadsto \color{blue}{\frac{4}{y} \cdot \left(\left(x + y \cdot 0.25\right) - z\right)} + 1 \]
    3. +-commutative99.8%

      \[\leadsto \frac{4}{y} \cdot \left(\color{blue}{\left(y \cdot 0.25 + x\right)} - z\right) + 1 \]
    4. associate--l+99.8%

      \[\leadsto \frac{4}{y} \cdot \color{blue}{\left(y \cdot 0.25 + \left(x - z\right)\right)} + 1 \]
    5. +-commutative99.8%

      \[\leadsto \frac{4}{y} \cdot \color{blue}{\left(\left(x - z\right) + y \cdot 0.25\right)} + 1 \]
    6. distribute-lft-in99.8%

      \[\leadsto \color{blue}{\left(\frac{4}{y} \cdot \left(x - z\right) + \frac{4}{y} \cdot \left(y \cdot 0.25\right)\right)} + 1 \]
    7. associate-+l+99.8%

      \[\leadsto \color{blue}{\frac{4}{y} \cdot \left(x - z\right) + \left(\frac{4}{y} \cdot \left(y \cdot 0.25\right) + 1\right)} \]
    8. associate-*l/100.0%

      \[\leadsto \color{blue}{\frac{4 \cdot \left(x - z\right)}{y}} + \left(\frac{4}{y} \cdot \left(y \cdot 0.25\right) + 1\right) \]
    9. associate-*l/100.0%

      \[\leadsto \frac{4 \cdot \left(x - z\right)}{y} + \left(\color{blue}{\frac{4 \cdot \left(y \cdot 0.25\right)}{y}} + 1\right) \]
    10. *-commutative100.0%

      \[\leadsto \frac{4 \cdot \left(x - z\right)}{y} + \left(\frac{\color{blue}{\left(y \cdot 0.25\right) \cdot 4}}{y} + 1\right) \]
    11. associate-*l*100.0%

      \[\leadsto \frac{4 \cdot \left(x - z\right)}{y} + \left(\frac{\color{blue}{y \cdot \left(0.25 \cdot 4\right)}}{y} + 1\right) \]
    12. metadata-eval100.0%

      \[\leadsto \frac{4 \cdot \left(x - z\right)}{y} + \left(\frac{y \cdot \color{blue}{1}}{y} + 1\right) \]
    13. *-rgt-identity100.0%

      \[\leadsto \frac{4 \cdot \left(x - z\right)}{y} + \left(\frac{\color{blue}{y}}{y} + 1\right) \]
    14. *-inverses100.0%

      \[\leadsto \frac{4 \cdot \left(x - z\right)}{y} + \left(\color{blue}{1} + 1\right) \]
    15. metadata-eval100.0%

      \[\leadsto \frac{4 \cdot \left(x - z\right)}{y} + \color{blue}{2} \]
  3. Simplified100.0%

    \[\leadsto \color{blue}{\frac{4 \cdot \left(x - z\right)}{y} + 2} \]
  4. Add Preprocessing
  5. Taylor expanded in x around 0 64.7%

    \[\leadsto \color{blue}{-4 \cdot \frac{z}{y}} + 2 \]
  6. Taylor expanded in z around 0 31.1%

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

Reproduce

?
herbie shell --seed 2024097 
(FPCore (x y z)
  :name "Data.Array.Repa.Algorithms.ColorRamp:rampColorHotToCold from repa-algorithms-3.4.0.1, C"
  :precision binary64
  (+ 1.0 (/ (* 4.0 (- (+ x (* y 0.25)) z)) y)))