Linear.Matrix:fromQuaternion from linear-1.19.1.3, A

Percentage Accurate: 94.9% → 100.0%
Time: 5.8s
Alternatives: 4
Speedup: 1.4×

Specification

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

\\
2 \cdot \left(x \cdot x - x \cdot y\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: 94.9% accurate, 1.0× speedup?

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

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

Alternative 1: 100.0% accurate, 1.4× speedup?

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

\\
\left(\left(x - y\right) \cdot x\right) \cdot 2
\end{array}
Derivation
  1. Initial program 96.5%

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

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

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

      \[\leadsto 2 \cdot \left(x \cdot x - \color{blue}{x \cdot y}\right) \]
    4. distribute-lft-out--N/A

      \[\leadsto 2 \cdot \color{blue}{\left(x \cdot \left(x - y\right)\right)} \]
    5. *-commutativeN/A

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

      \[\leadsto 2 \cdot \color{blue}{\left(\left(x - y\right) \cdot x\right)} \]
    7. lower--.f64100.0

      \[\leadsto 2 \cdot \left(\color{blue}{\left(x - y\right)} \cdot x\right) \]
  4. Applied rewrites100.0%

    \[\leadsto 2 \cdot \color{blue}{\left(\left(x - y\right) \cdot x\right)} \]
  5. Final simplification100.0%

    \[\leadsto \left(\left(x - y\right) \cdot x\right) \cdot 2 \]
  6. Add Preprocessing

Alternative 2: 84.2% accurate, 0.8× speedup?

\[\begin{array}{l} \\ \begin{array}{l} t_0 := \left(y \cdot x\right) \cdot -2\\ \mathbf{if}\;y \leq -4.4 \cdot 10^{+38}:\\ \;\;\;\;t\_0\\ \mathbf{elif}\;y \leq 1.65 \cdot 10^{-13}:\\ \;\;\;\;\left(x + x\right) \cdot x\\ \mathbf{else}:\\ \;\;\;\;t\_0\\ \end{array} \end{array} \]
(FPCore (x y)
 :precision binary64
 (let* ((t_0 (* (* y x) -2.0)))
   (if (<= y -4.4e+38) t_0 (if (<= y 1.65e-13) (* (+ x x) x) t_0))))
double code(double x, double y) {
	double t_0 = (y * x) * -2.0;
	double tmp;
	if (y <= -4.4e+38) {
		tmp = t_0;
	} else if (y <= 1.65e-13) {
		tmp = (x + x) * x;
	} else {
		tmp = t_0;
	}
	return tmp;
}
real(8) function code(x, y)
    real(8), intent (in) :: x
    real(8), intent (in) :: y
    real(8) :: t_0
    real(8) :: tmp
    t_0 = (y * x) * (-2.0d0)
    if (y <= (-4.4d+38)) then
        tmp = t_0
    else if (y <= 1.65d-13) then
        tmp = (x + x) * x
    else
        tmp = t_0
    end if
    code = tmp
end function
public static double code(double x, double y) {
	double t_0 = (y * x) * -2.0;
	double tmp;
	if (y <= -4.4e+38) {
		tmp = t_0;
	} else if (y <= 1.65e-13) {
		tmp = (x + x) * x;
	} else {
		tmp = t_0;
	}
	return tmp;
}
def code(x, y):
	t_0 = (y * x) * -2.0
	tmp = 0
	if y <= -4.4e+38:
		tmp = t_0
	elif y <= 1.65e-13:
		tmp = (x + x) * x
	else:
		tmp = t_0
	return tmp
function code(x, y)
	t_0 = Float64(Float64(y * x) * -2.0)
	tmp = 0.0
	if (y <= -4.4e+38)
		tmp = t_0;
	elseif (y <= 1.65e-13)
		tmp = Float64(Float64(x + x) * x);
	else
		tmp = t_0;
	end
	return tmp
end
function tmp_2 = code(x, y)
	t_0 = (y * x) * -2.0;
	tmp = 0.0;
	if (y <= -4.4e+38)
		tmp = t_0;
	elseif (y <= 1.65e-13)
		tmp = (x + x) * x;
	else
		tmp = t_0;
	end
	tmp_2 = tmp;
end
code[x_, y_] := Block[{t$95$0 = N[(N[(y * x), $MachinePrecision] * -2.0), $MachinePrecision]}, If[LessEqual[y, -4.4e+38], t$95$0, If[LessEqual[y, 1.65e-13], N[(N[(x + x), $MachinePrecision] * x), $MachinePrecision], t$95$0]]]
\begin{array}{l}

\\
\begin{array}{l}
t_0 := \left(y \cdot x\right) \cdot -2\\
\mathbf{if}\;y \leq -4.4 \cdot 10^{+38}:\\
\;\;\;\;t\_0\\

\mathbf{elif}\;y \leq 1.65 \cdot 10^{-13}:\\
\;\;\;\;\left(x + x\right) \cdot x\\

\mathbf{else}:\\
\;\;\;\;t\_0\\


\end{array}
\end{array}
Derivation
  1. Split input into 2 regimes
  2. if y < -4.40000000000000013e38 or 1.65e-13 < y

    1. Initial program 92.6%

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

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

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

        \[\leadsto -2 \cdot \color{blue}{\left(y \cdot x\right)} \]
      3. lower-*.f6487.8

        \[\leadsto -2 \cdot \color{blue}{\left(y \cdot x\right)} \]
    5. Applied rewrites87.8%

      \[\leadsto \color{blue}{-2 \cdot \left(y \cdot x\right)} \]

    if -4.40000000000000013e38 < y < 1.65e-13

    1. Initial program 100.0%

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

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

        \[\leadsto \color{blue}{{x}^{2} \cdot 2} \]
      2. lower-*.f64N/A

        \[\leadsto \color{blue}{{x}^{2} \cdot 2} \]
      3. unpow2N/A

        \[\leadsto \color{blue}{\left(x \cdot x\right)} \cdot 2 \]
      4. lower-*.f6490.2

        \[\leadsto \color{blue}{\left(x \cdot x\right)} \cdot 2 \]
    5. Applied rewrites90.2%

      \[\leadsto \color{blue}{\left(x \cdot x\right) \cdot 2} \]
    6. Step-by-step derivation
      1. Applied rewrites90.3%

        \[\leadsto \left(x \cdot 2\right) \cdot \color{blue}{x} \]
      2. Step-by-step derivation
        1. Applied rewrites90.3%

          \[\leadsto \left(x + x\right) \cdot x \]
      3. Recombined 2 regimes into one program.
      4. Final simplification89.1%

        \[\leadsto \begin{array}{l} \mathbf{if}\;y \leq -4.4 \cdot 10^{+38}:\\ \;\;\;\;\left(y \cdot x\right) \cdot -2\\ \mathbf{elif}\;y \leq 1.65 \cdot 10^{-13}:\\ \;\;\;\;\left(x + x\right) \cdot x\\ \mathbf{else}:\\ \;\;\;\;\left(y \cdot x\right) \cdot -2\\ \end{array} \]
      5. Add Preprocessing

      Alternative 3: 59.7% accurate, 2.1× speedup?

      \[\begin{array}{l} \\ \left(x + x\right) \cdot x \end{array} \]
      (FPCore (x y) :precision binary64 (* (+ x x) x))
      double code(double x, double y) {
      	return (x + x) * x;
      }
      
      real(8) function code(x, y)
          real(8), intent (in) :: x
          real(8), intent (in) :: y
          code = (x + x) * x
      end function
      
      public static double code(double x, double y) {
      	return (x + x) * x;
      }
      
      def code(x, y):
      	return (x + x) * x
      
      function code(x, y)
      	return Float64(Float64(x + x) * x)
      end
      
      function tmp = code(x, y)
      	tmp = (x + x) * x;
      end
      
      code[x_, y_] := N[(N[(x + x), $MachinePrecision] * x), $MachinePrecision]
      
      \begin{array}{l}
      
      \\
      \left(x + x\right) \cdot x
      \end{array}
      
      Derivation
      1. Initial program 96.5%

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

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

          \[\leadsto \color{blue}{{x}^{2} \cdot 2} \]
        2. lower-*.f64N/A

          \[\leadsto \color{blue}{{x}^{2} \cdot 2} \]
        3. unpow2N/A

          \[\leadsto \color{blue}{\left(x \cdot x\right)} \cdot 2 \]
        4. lower-*.f6459.1

          \[\leadsto \color{blue}{\left(x \cdot x\right)} \cdot 2 \]
      5. Applied rewrites59.1%

        \[\leadsto \color{blue}{\left(x \cdot x\right) \cdot 2} \]
      6. Step-by-step derivation
        1. Applied rewrites59.1%

          \[\leadsto \left(x \cdot 2\right) \cdot \color{blue}{x} \]
        2. Step-by-step derivation
          1. Applied rewrites59.1%

            \[\leadsto \left(x + x\right) \cdot x \]
          2. Add Preprocessing

          Alternative 4: 11.6% accurate, 19.0× speedup?

          \[\begin{array}{l} \\ 0 \end{array} \]
          (FPCore (x y) :precision binary64 0.0)
          double code(double x, double y) {
          	return 0.0;
          }
          
          real(8) function code(x, y)
              real(8), intent (in) :: x
              real(8), intent (in) :: y
              code = 0.0d0
          end function
          
          public static double code(double x, double y) {
          	return 0.0;
          }
          
          def code(x, y):
          	return 0.0
          
          function code(x, y)
          	return 0.0
          end
          
          function tmp = code(x, y)
          	tmp = 0.0;
          end
          
          code[x_, y_] := 0.0
          
          \begin{array}{l}
          
          \\
          0
          \end{array}
          
          Derivation
          1. Initial program 96.5%

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

              \[\leadsto \color{blue}{2 \cdot \left(x \cdot x - x \cdot y\right)} \]
            2. count-2-revN/A

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

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

              \[\leadsto \left(x \cdot x - x \cdot y\right) + \left(x \cdot x - \color{blue}{x \cdot y}\right) \]
            5. cancel-sub-sign-invN/A

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

              \[\leadsto \left(x \cdot x - x \cdot y\right) + \left(\color{blue}{x \cdot x} + \left(\mathsf{neg}\left(x\right)\right) \cdot y\right) \]
            7. sqr-neg-revN/A

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

              \[\leadsto \left(x \cdot x - x \cdot y\right) + \color{blue}{\left(\mathsf{neg}\left(x\right)\right) \cdot \left(\left(\mathsf{neg}\left(x\right)\right) + y\right)} \]
            9. cancel-sign-sub-invN/A

              \[\leadsto \color{blue}{\left(x \cdot x - x \cdot y\right) - \left(\mathsf{neg}\left(\left(\mathsf{neg}\left(x\right)\right)\right)\right) \cdot \left(\left(\mathsf{neg}\left(x\right)\right) + y\right)} \]
            10. remove-double-negN/A

              \[\leadsto \left(x \cdot x - x \cdot y\right) - \color{blue}{x} \cdot \left(\left(\mathsf{neg}\left(x\right)\right) + y\right) \]
            11. unpow1N/A

              \[\leadsto \left(x \cdot x - x \cdot y\right) - \color{blue}{{x}^{1}} \cdot \left(\left(\mathsf{neg}\left(x\right)\right) + y\right) \]
            12. metadata-evalN/A

              \[\leadsto \left(x \cdot x - x \cdot y\right) - {x}^{\color{blue}{\left(\frac{2}{2}\right)}} \cdot \left(\left(\mathsf{neg}\left(x\right)\right) + y\right) \]
            13. sqrt-pow1N/A

              \[\leadsto \left(x \cdot x - x \cdot y\right) - \color{blue}{\sqrt{{x}^{2}}} \cdot \left(\left(\mathsf{neg}\left(x\right)\right) + y\right) \]
            14. pow2N/A

              \[\leadsto \left(x \cdot x - x \cdot y\right) - \sqrt{\color{blue}{x \cdot x}} \cdot \left(\left(\mathsf{neg}\left(x\right)\right) + y\right) \]
            15. sqr-neg-revN/A

              \[\leadsto \left(x \cdot x - x \cdot y\right) - \sqrt{\color{blue}{\left(\mathsf{neg}\left(x\right)\right) \cdot \left(\mathsf{neg}\left(x\right)\right)}} \cdot \left(\left(\mathsf{neg}\left(x\right)\right) + y\right) \]
            16. pow2N/A

              \[\leadsto \left(x \cdot x - x \cdot y\right) - \sqrt{\color{blue}{{\left(\mathsf{neg}\left(x\right)\right)}^{2}}} \cdot \left(\left(\mathsf{neg}\left(x\right)\right) + y\right) \]
            17. sqrt-pow1N/A

              \[\leadsto \left(x \cdot x - x \cdot y\right) - \color{blue}{{\left(\mathsf{neg}\left(x\right)\right)}^{\left(\frac{2}{2}\right)}} \cdot \left(\left(\mathsf{neg}\left(x\right)\right) + y\right) \]
            18. metadata-evalN/A

              \[\leadsto \left(x \cdot x - x \cdot y\right) - {\left(\mathsf{neg}\left(x\right)\right)}^{\color{blue}{1}} \cdot \left(\left(\mathsf{neg}\left(x\right)\right) + y\right) \]
            19. unpow1N/A

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

              \[\leadsto \left(x \cdot x - x \cdot y\right) - \color{blue}{\left(\left(\mathsf{neg}\left(x\right)\right) \cdot \left(\mathsf{neg}\left(x\right)\right) + \left(\mathsf{neg}\left(x\right)\right) \cdot y\right)} \]
            21. sqr-neg-revN/A

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

              \[\leadsto \left(x \cdot x - x \cdot y\right) - \left(\color{blue}{x \cdot x} + \left(\mathsf{neg}\left(x\right)\right) \cdot y\right) \]
            23. cancel-sub-sign-invN/A

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

              \[\leadsto \left(x \cdot x - x \cdot y\right) - \left(x \cdot x - \color{blue}{x \cdot y}\right) \]
          4. Applied rewrites12.3%

            \[\leadsto \color{blue}{0} \]
          5. Add Preprocessing

          Developer Target 1: 100.0% accurate, 1.4× speedup?

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

          Reproduce

          ?
          herbie shell --seed 2024298 
          (FPCore (x y)
            :name "Linear.Matrix:fromQuaternion from linear-1.19.1.3, A"
            :precision binary64
          
            :alt
            (! :herbie-platform default (* (* x 2) (- x y)))
          
            (* 2.0 (- (* x x) (* x y))))