Diagrams.TwoD.Arc:arcBetween from diagrams-lib-1.3.0.3

Percentage Accurate: 50.6% → 80.5%
Time: 1.7s
Alternatives: 3
Speedup: 2.6×

Specification

?
\[\begin{array}{l} t_0 := \left(y \cdot 4\right) \cdot y\\ \frac{x \cdot x - t\_0}{x \cdot x + t\_0} \end{array} \]
(FPCore (x y)
  :precision binary64
  :pre TRUE
  (let* ((t_0 (* (* y 4.0) y))) (/ (- (* x x) t_0) (+ (* x x) t_0))))
double code(double x, double y) {
	double t_0 = (y * 4.0) * y;
	return ((x * x) - t_0) / ((x * x) + t_0);
}
real(8) function code(x, y)
use fmin_fmax_functions
    real(8), intent (in) :: x
    real(8), intent (in) :: y
    real(8) :: t_0
    t_0 = (y * 4.0d0) * y
    code = ((x * x) - t_0) / ((x * x) + t_0)
end function
public static double code(double x, double y) {
	double t_0 = (y * 4.0) * y;
	return ((x * x) - t_0) / ((x * x) + t_0);
}
def code(x, y):
	t_0 = (y * 4.0) * y
	return ((x * x) - t_0) / ((x * x) + t_0)
function code(x, y)
	t_0 = Float64(Float64(y * 4.0) * y)
	return Float64(Float64(Float64(x * x) - t_0) / Float64(Float64(x * x) + t_0))
end
function tmp = code(x, y)
	t_0 = (y * 4.0) * y;
	tmp = ((x * x) - t_0) / ((x * x) + t_0);
end
code[x_, y_] := Block[{t$95$0 = N[(N[(y * 4.0), $MachinePrecision] * y), $MachinePrecision]}, N[(N[(N[(x * x), $MachinePrecision] - t$95$0), $MachinePrecision] / N[(N[(x * x), $MachinePrecision] + t$95$0), $MachinePrecision]), $MachinePrecision]]
f(x, y):
	x in [-inf, +inf],
	y in [-inf, +inf]
code: THEORY
BEGIN
f(x, y: real): real =
	LET t_0 = ((y * (4)) * y) IN
	((x * x) - t_0) / ((x * x) + t_0)
END code
\begin{array}{l}
t_0 := \left(y \cdot 4\right) \cdot y\\
\frac{x \cdot x - t\_0}{x \cdot x + t\_0}
\end{array}

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 3 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: 50.6% accurate, 1.0× speedup?

\[\begin{array}{l} t_0 := \left(y \cdot 4\right) \cdot y\\ \frac{x \cdot x - t\_0}{x \cdot x + t\_0} \end{array} \]
(FPCore (x y)
  :precision binary64
  :pre TRUE
  (let* ((t_0 (* (* y 4.0) y))) (/ (- (* x x) t_0) (+ (* x x) t_0))))
double code(double x, double y) {
	double t_0 = (y * 4.0) * y;
	return ((x * x) - t_0) / ((x * x) + t_0);
}
real(8) function code(x, y)
use fmin_fmax_functions
    real(8), intent (in) :: x
    real(8), intent (in) :: y
    real(8) :: t_0
    t_0 = (y * 4.0d0) * y
    code = ((x * x) - t_0) / ((x * x) + t_0)
end function
public static double code(double x, double y) {
	double t_0 = (y * 4.0) * y;
	return ((x * x) - t_0) / ((x * x) + t_0);
}
def code(x, y):
	t_0 = (y * 4.0) * y
	return ((x * x) - t_0) / ((x * x) + t_0)
function code(x, y)
	t_0 = Float64(Float64(y * 4.0) * y)
	return Float64(Float64(Float64(x * x) - t_0) / Float64(Float64(x * x) + t_0))
end
function tmp = code(x, y)
	t_0 = (y * 4.0) * y;
	tmp = ((x * x) - t_0) / ((x * x) + t_0);
end
code[x_, y_] := Block[{t$95$0 = N[(N[(y * 4.0), $MachinePrecision] * y), $MachinePrecision]}, N[(N[(N[(x * x), $MachinePrecision] - t$95$0), $MachinePrecision] / N[(N[(x * x), $MachinePrecision] + t$95$0), $MachinePrecision]), $MachinePrecision]]
f(x, y):
	x in [-inf, +inf],
	y in [-inf, +inf]
code: THEORY
BEGIN
f(x, y: real): real =
	LET t_0 = ((y * (4)) * y) IN
	((x * x) - t_0) / ((x * x) + t_0)
END code
\begin{array}{l}
t_0 := \left(y \cdot 4\right) \cdot y\\
\frac{x \cdot x - t\_0}{x \cdot x + t\_0}
\end{array}

Alternative 1: 80.5% accurate, 0.6× speedup?

\[\begin{array}{l} t_0 := \left(y \cdot 4\right) \cdot y\\ \mathbf{if}\;t\_0 \leq 2 \cdot 10^{-207}:\\ \;\;\;\;1\\ \mathbf{elif}\;t\_0 \leq 10^{+270}:\\ \;\;\;\;\frac{\mathsf{fma}\left(y, -4 \cdot y, x \cdot x\right)}{\mathsf{fma}\left(4 \cdot y, y, x \cdot x\right)}\\ \mathbf{else}:\\ \;\;\;\;-1\\ \end{array} \]
(FPCore (x y)
  :precision binary64
  :pre TRUE
  (let* ((t_0 (* (* y 4.0) y)))
  (if (<= t_0 2e-207)
    1.0
    (if (<= t_0 1e+270)
      (/ (fma y (* -4.0 y) (* x x)) (fma (* 4.0 y) y (* x x)))
      -1.0))))
double code(double x, double y) {
	double t_0 = (y * 4.0) * y;
	double tmp;
	if (t_0 <= 2e-207) {
		tmp = 1.0;
	} else if (t_0 <= 1e+270) {
		tmp = fma(y, (-4.0 * y), (x * x)) / fma((4.0 * y), y, (x * x));
	} else {
		tmp = -1.0;
	}
	return tmp;
}
function code(x, y)
	t_0 = Float64(Float64(y * 4.0) * y)
	tmp = 0.0
	if (t_0 <= 2e-207)
		tmp = 1.0;
	elseif (t_0 <= 1e+270)
		tmp = Float64(fma(y, Float64(-4.0 * y), Float64(x * x)) / fma(Float64(4.0 * y), y, Float64(x * x)));
	else
		tmp = -1.0;
	end
	return tmp
end
code[x_, y_] := Block[{t$95$0 = N[(N[(y * 4.0), $MachinePrecision] * y), $MachinePrecision]}, If[LessEqual[t$95$0, 2e-207], 1.0, If[LessEqual[t$95$0, 1e+270], N[(N[(y * N[(-4.0 * y), $MachinePrecision] + N[(x * x), $MachinePrecision]), $MachinePrecision] / N[(N[(4.0 * y), $MachinePrecision] * y + N[(x * x), $MachinePrecision]), $MachinePrecision]), $MachinePrecision], -1.0]]]
f(x, y):
	x in [-inf, +inf],
	y in [-inf, +inf]
code: THEORY
BEGIN
f(x, y: real): real =
	LET t_0 = ((y * (4)) * y) IN
		LET tmp_1 = IF (t_0 <= (1000000000000000046753818885456127989189605431330410286841364872744016439394555894610368258180303336939076888134044950289326168184662430331474313277416979816387389279864637935586997520238352311022660078293728671385192933261062303434752638026781377548741967884639283445760)) THEN (((y * ((-4) * y)) + (x * x)) / ((((4) * y) * y) + (x * x))) ELSE (-1) ENDIF IN
		LET tmp = IF (t_0 <= (19999999999999998500057988813309052158878670450379984832068198023382673287842269034781394828896796779433247043788236241482444063890001975599707774292971993779901934784385820134175074030084732147960592089873240346543356281598004867966117982185940517430870992813877962560518850311709787416505414965043679965885414329927709509480949808390423899621647146240513041589180574625500794646704022904591156621969054121565133570036450400610544364643046101101917584504075654207402340596223998362723049009893883098953892840654589235782623291015625e-739)) THEN (1) ELSE tmp_1 ENDIF IN
	tmp
END code
\begin{array}{l}
t_0 := \left(y \cdot 4\right) \cdot y\\
\mathbf{if}\;t\_0 \leq 2 \cdot 10^{-207}:\\
\;\;\;\;1\\

\mathbf{elif}\;t\_0 \leq 10^{+270}:\\
\;\;\;\;\frac{\mathsf{fma}\left(y, -4 \cdot y, x \cdot x\right)}{\mathsf{fma}\left(4 \cdot y, y, x \cdot x\right)}\\

\mathbf{else}:\\
\;\;\;\;-1\\


\end{array}
Derivation
  1. Split input into 3 regimes
  2. if (*.f64 (*.f64 y #s(literal 4 binary64)) y) < 1.9999999999999999e-207

    1. Initial program 50.6%

      \[\frac{x \cdot x - \left(y \cdot 4\right) \cdot y}{x \cdot x + \left(y \cdot 4\right) \cdot y} \]
    2. Taylor expanded in x around inf

      \[\leadsto 1 \]
    3. Step-by-step derivation
      1. Applied rewrites50.8%

        \[\leadsto 1 \]

      if 1.9999999999999999e-207 < (*.f64 (*.f64 y #s(literal 4 binary64)) y) < 1e270

      1. Initial program 50.6%

        \[\frac{x \cdot x - \left(y \cdot 4\right) \cdot y}{x \cdot x + \left(y \cdot 4\right) \cdot y} \]
      2. Applied rewrites50.5%

        \[\leadsto \frac{\mathsf{fma}\left(y \cdot y, -4, x \cdot x\right)}{\mathsf{fma}\left(4 \cdot y, y, x \cdot x\right)} \]
      3. Step-by-step derivation
        1. Applied rewrites50.6%

          \[\leadsto \frac{\mathsf{fma}\left(y, -4 \cdot y, x \cdot x\right)}{\mathsf{fma}\left(4 \cdot y, y, x \cdot x\right)} \]

        if 1e270 < (*.f64 (*.f64 y #s(literal 4 binary64)) y)

        1. Initial program 50.6%

          \[\frac{x \cdot x - \left(y \cdot 4\right) \cdot y}{x \cdot x + \left(y \cdot 4\right) \cdot y} \]
        2. Taylor expanded in x around 0

          \[\leadsto -1 \]
        3. Step-by-step derivation
          1. Applied rewrites49.7%

            \[\leadsto -1 \]
        4. Recombined 3 regimes into one program.
        5. Add Preprocessing

        Alternative 2: 74.9% accurate, 2.6× speedup?

        \[\begin{array}{l} \mathbf{if}\;\left(y \cdot 4\right) \cdot y \leq 171156406.40053666:\\ \;\;\;\;1\\ \mathbf{else}:\\ \;\;\;\;-1\\ \end{array} \]
        (FPCore (x y)
          :precision binary64
          :pre TRUE
          (if (<= (* (* y 4.0) y) 171156406.40053666) 1.0 -1.0))
        double code(double x, double y) {
        	double tmp;
        	if (((y * 4.0) * y) <= 171156406.40053666) {
        		tmp = 1.0;
        	} else {
        		tmp = -1.0;
        	}
        	return tmp;
        }
        
        real(8) function code(x, y)
        use fmin_fmax_functions
            real(8), intent (in) :: x
            real(8), intent (in) :: y
            real(8) :: tmp
            if (((y * 4.0d0) * y) <= 171156406.40053666d0) then
                tmp = 1.0d0
            else
                tmp = -1.0d0
            end if
            code = tmp
        end function
        
        public static double code(double x, double y) {
        	double tmp;
        	if (((y * 4.0) * y) <= 171156406.40053666) {
        		tmp = 1.0;
        	} else {
        		tmp = -1.0;
        	}
        	return tmp;
        }
        
        def code(x, y):
        	tmp = 0
        	if ((y * 4.0) * y) <= 171156406.40053666:
        		tmp = 1.0
        	else:
        		tmp = -1.0
        	return tmp
        
        function code(x, y)
        	tmp = 0.0
        	if (Float64(Float64(y * 4.0) * y) <= 171156406.40053666)
        		tmp = 1.0;
        	else
        		tmp = -1.0;
        	end
        	return tmp
        end
        
        function tmp_2 = code(x, y)
        	tmp = 0.0;
        	if (((y * 4.0) * y) <= 171156406.40053666)
        		tmp = 1.0;
        	else
        		tmp = -1.0;
        	end
        	tmp_2 = tmp;
        end
        
        code[x_, y_] := If[LessEqual[N[(N[(y * 4.0), $MachinePrecision] * y), $MachinePrecision], 171156406.40053666], 1.0, -1.0]
        
        f(x, y):
        	x in [-inf, +inf],
        	y in [-inf, +inf]
        code: THEORY
        BEGIN
        f(x, y: real): real =
        	LET tmp = IF (((y * (4)) * y) <= (17115640640053665637969970703125e-23)) THEN (1) ELSE (-1) ENDIF IN
        	tmp
        END code
        \begin{array}{l}
        \mathbf{if}\;\left(y \cdot 4\right) \cdot y \leq 171156406.40053666:\\
        \;\;\;\;1\\
        
        \mathbf{else}:\\
        \;\;\;\;-1\\
        
        
        \end{array}
        
        Derivation
        1. Split input into 2 regimes
        2. if (*.f64 (*.f64 y #s(literal 4 binary64)) y) < 171156406.40053666

          1. Initial program 50.6%

            \[\frac{x \cdot x - \left(y \cdot 4\right) \cdot y}{x \cdot x + \left(y \cdot 4\right) \cdot y} \]
          2. Taylor expanded in x around inf

            \[\leadsto 1 \]
          3. Step-by-step derivation
            1. Applied rewrites50.8%

              \[\leadsto 1 \]

            if 171156406.40053666 < (*.f64 (*.f64 y #s(literal 4 binary64)) y)

            1. Initial program 50.6%

              \[\frac{x \cdot x - \left(y \cdot 4\right) \cdot y}{x \cdot x + \left(y \cdot 4\right) \cdot y} \]
            2. Taylor expanded in x around 0

              \[\leadsto -1 \]
            3. Step-by-step derivation
              1. Applied rewrites49.7%

                \[\leadsto -1 \]
            4. Recombined 2 regimes into one program.
            5. Add Preprocessing

            Alternative 3: 49.7% accurate, 28.0× speedup?

            \[-1 \]
            (FPCore (x y)
              :precision binary64
              :pre TRUE
              -1.0)
            double code(double x, double y) {
            	return -1.0;
            }
            
            real(8) function code(x, y)
            use fmin_fmax_functions
                real(8), intent (in) :: x
                real(8), intent (in) :: y
                code = -1.0d0
            end function
            
            public static double code(double x, double y) {
            	return -1.0;
            }
            
            def code(x, y):
            	return -1.0
            
            function code(x, y)
            	return -1.0
            end
            
            function tmp = code(x, y)
            	tmp = -1.0;
            end
            
            code[x_, y_] := -1.0
            
            f(x, y):
            	x in [-inf, +inf],
            	y in [-inf, +inf]
            code: THEORY
            BEGIN
            f(x, y: real): real =
            	-1
            END code
            -1
            
            Derivation
            1. Initial program 50.6%

              \[\frac{x \cdot x - \left(y \cdot 4\right) \cdot y}{x \cdot x + \left(y \cdot 4\right) \cdot y} \]
            2. Taylor expanded in x around 0

              \[\leadsto -1 \]
            3. Step-by-step derivation
              1. Applied rewrites49.7%

                \[\leadsto -1 \]
              2. Add Preprocessing

              Reproduce

              ?
              herbie shell --seed 2026092 
              (FPCore (x y)
                :name "Diagrams.TwoD.Arc:arcBetween from diagrams-lib-1.3.0.3"
                :precision binary64
                (/ (- (* x x) (* (* y 4.0) y)) (+ (* x x) (* (* y 4.0) y))))