Diagrams.Trail:splitAtParam from diagrams-lib-1.3.0.3, B

Percentage Accurate: 88.6% → 99.6%
Time: 4.0s
Alternatives: 3
Speedup: 0.7×

Specification

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

\\
\frac{x \cdot y}{y + 1}
\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 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: 88.6% accurate, 1.0× speedup?

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

\\
\frac{x \cdot y}{y + 1}
\end{array}

Alternative 1: 99.6% accurate, 0.4× speedup?

\[\begin{array}{l} x\_m = \left|x\right| \\ x\_s = \mathsf{copysign}\left(1, x\right) \\ \begin{array}{l} t_0 := \frac{y \cdot x\_m}{1 + y}\\ x\_s \cdot \begin{array}{l} \mathbf{if}\;t\_0 \leq 2 \cdot 10^{+251}:\\ \;\;\;\;t\_0\\ \mathbf{else}:\\ \;\;\;\;x\_m - \frac{x\_m}{y}\\ \end{array} \end{array} \end{array} \]
x\_m = (fabs.f64 x)
x\_s = (copysign.f64 #s(literal 1 binary64) x)
(FPCore (x_s x_m y)
 :precision binary64
 (let* ((t_0 (/ (* y x_m) (+ 1.0 y))))
   (* x_s (if (<= t_0 2e+251) t_0 (- x_m (/ x_m y))))))
x\_m = fabs(x);
x\_s = copysign(1.0, x);
double code(double x_s, double x_m, double y) {
	double t_0 = (y * x_m) / (1.0 + y);
	double tmp;
	if (t_0 <= 2e+251) {
		tmp = t_0;
	} else {
		tmp = x_m - (x_m / y);
	}
	return x_s * tmp;
}
x\_m = abs(x)
x\_s = copysign(1.0d0, x)
real(8) function code(x_s, x_m, y)
    real(8), intent (in) :: x_s
    real(8), intent (in) :: x_m
    real(8), intent (in) :: y
    real(8) :: t_0
    real(8) :: tmp
    t_0 = (y * x_m) / (1.0d0 + y)
    if (t_0 <= 2d+251) then
        tmp = t_0
    else
        tmp = x_m - (x_m / y)
    end if
    code = x_s * tmp
end function
x\_m = Math.abs(x);
x\_s = Math.copySign(1.0, x);
public static double code(double x_s, double x_m, double y) {
	double t_0 = (y * x_m) / (1.0 + y);
	double tmp;
	if (t_0 <= 2e+251) {
		tmp = t_0;
	} else {
		tmp = x_m - (x_m / y);
	}
	return x_s * tmp;
}
x\_m = math.fabs(x)
x\_s = math.copysign(1.0, x)
def code(x_s, x_m, y):
	t_0 = (y * x_m) / (1.0 + y)
	tmp = 0
	if t_0 <= 2e+251:
		tmp = t_0
	else:
		tmp = x_m - (x_m / y)
	return x_s * tmp
x\_m = abs(x)
x\_s = copysign(1.0, x)
function code(x_s, x_m, y)
	t_0 = Float64(Float64(y * x_m) / Float64(1.0 + y))
	tmp = 0.0
	if (t_0 <= 2e+251)
		tmp = t_0;
	else
		tmp = Float64(x_m - Float64(x_m / y));
	end
	return Float64(x_s * tmp)
end
x\_m = abs(x);
x\_s = sign(x) * abs(1.0);
function tmp_2 = code(x_s, x_m, y)
	t_0 = (y * x_m) / (1.0 + y);
	tmp = 0.0;
	if (t_0 <= 2e+251)
		tmp = t_0;
	else
		tmp = x_m - (x_m / y);
	end
	tmp_2 = x_s * tmp;
end
x\_m = N[Abs[x], $MachinePrecision]
x\_s = N[With[{TMP1 = Abs[1.0], TMP2 = Sign[x]}, TMP1 * If[TMP2 == 0, 1, TMP2]], $MachinePrecision]
code[x$95$s_, x$95$m_, y_] := Block[{t$95$0 = N[(N[(y * x$95$m), $MachinePrecision] / N[(1.0 + y), $MachinePrecision]), $MachinePrecision]}, N[(x$95$s * If[LessEqual[t$95$0, 2e+251], t$95$0, N[(x$95$m - N[(x$95$m / y), $MachinePrecision]), $MachinePrecision]]), $MachinePrecision]]
\begin{array}{l}
x\_m = \left|x\right|
\\
x\_s = \mathsf{copysign}\left(1, x\right)

\\
\begin{array}{l}
t_0 := \frac{y \cdot x\_m}{1 + y}\\
x\_s \cdot \begin{array}{l}
\mathbf{if}\;t\_0 \leq 2 \cdot 10^{+251}:\\
\;\;\;\;t\_0\\

\mathbf{else}:\\
\;\;\;\;x\_m - \frac{x\_m}{y}\\


\end{array}
\end{array}
\end{array}
Derivation
  1. Split input into 2 regimes
  2. if (/.f64 (*.f64 x y) (+.f64 y #s(literal 1 binary64))) < 2.0000000000000001e251

    1. Initial program 96.0%

      \[\frac{x \cdot y}{y + 1} \]
    2. Add Preprocessing

    if 2.0000000000000001e251 < (/.f64 (*.f64 x y) (+.f64 y #s(literal 1 binary64)))

    1. Initial program 6.9%

      \[\frac{x \cdot y}{y + 1} \]
    2. Add Preprocessing
    3. Taylor expanded in y around inf

      \[\leadsto \color{blue}{x + -1 \cdot \frac{x}{y}} \]
    4. Step-by-step derivation
      1. mul-1-negN/A

        \[\leadsto x + \color{blue}{\left(\mathsf{neg}\left(\frac{x}{y}\right)\right)} \]
      2. unsub-negN/A

        \[\leadsto \color{blue}{x - \frac{x}{y}} \]
      3. lower--.f64N/A

        \[\leadsto \color{blue}{x - \frac{x}{y}} \]
      4. lower-/.f64100.0

        \[\leadsto x - \color{blue}{\frac{x}{y}} \]
    5. Applied rewrites100.0%

      \[\leadsto \color{blue}{x - \frac{x}{y}} \]
  3. Recombined 2 regimes into one program.
  4. Final simplification96.2%

    \[\leadsto \begin{array}{l} \mathbf{if}\;\frac{y \cdot x}{1 + y} \leq 2 \cdot 10^{+251}:\\ \;\;\;\;\frac{y \cdot x}{1 + y}\\ \mathbf{else}:\\ \;\;\;\;x - \frac{x}{y}\\ \end{array} \]
  5. Add Preprocessing

Alternative 2: 98.9% accurate, 0.7× speedup?

\[\begin{array}{l} x\_m = \left|x\right| \\ x\_s = \mathsf{copysign}\left(1, x\right) \\ \begin{array}{l} t_0 := x\_m - \frac{x\_m}{y}\\ x\_s \cdot \begin{array}{l} \mathbf{if}\;y \leq -1:\\ \;\;\;\;t\_0\\ \mathbf{elif}\;y \leq 1:\\ \;\;\;\;\left(x\_m - y \cdot x\_m\right) \cdot y\\ \mathbf{else}:\\ \;\;\;\;t\_0\\ \end{array} \end{array} \end{array} \]
x\_m = (fabs.f64 x)
x\_s = (copysign.f64 #s(literal 1 binary64) x)
(FPCore (x_s x_m y)
 :precision binary64
 (let* ((t_0 (- x_m (/ x_m y))))
   (* x_s (if (<= y -1.0) t_0 (if (<= y 1.0) (* (- x_m (* y x_m)) y) t_0)))))
x\_m = fabs(x);
x\_s = copysign(1.0, x);
double code(double x_s, double x_m, double y) {
	double t_0 = x_m - (x_m / y);
	double tmp;
	if (y <= -1.0) {
		tmp = t_0;
	} else if (y <= 1.0) {
		tmp = (x_m - (y * x_m)) * y;
	} else {
		tmp = t_0;
	}
	return x_s * tmp;
}
x\_m = abs(x)
x\_s = copysign(1.0d0, x)
real(8) function code(x_s, x_m, y)
    real(8), intent (in) :: x_s
    real(8), intent (in) :: x_m
    real(8), intent (in) :: y
    real(8) :: t_0
    real(8) :: tmp
    t_0 = x_m - (x_m / y)
    if (y <= (-1.0d0)) then
        tmp = t_0
    else if (y <= 1.0d0) then
        tmp = (x_m - (y * x_m)) * y
    else
        tmp = t_0
    end if
    code = x_s * tmp
end function
x\_m = Math.abs(x);
x\_s = Math.copySign(1.0, x);
public static double code(double x_s, double x_m, double y) {
	double t_0 = x_m - (x_m / y);
	double tmp;
	if (y <= -1.0) {
		tmp = t_0;
	} else if (y <= 1.0) {
		tmp = (x_m - (y * x_m)) * y;
	} else {
		tmp = t_0;
	}
	return x_s * tmp;
}
x\_m = math.fabs(x)
x\_s = math.copysign(1.0, x)
def code(x_s, x_m, y):
	t_0 = x_m - (x_m / y)
	tmp = 0
	if y <= -1.0:
		tmp = t_0
	elif y <= 1.0:
		tmp = (x_m - (y * x_m)) * y
	else:
		tmp = t_0
	return x_s * tmp
x\_m = abs(x)
x\_s = copysign(1.0, x)
function code(x_s, x_m, y)
	t_0 = Float64(x_m - Float64(x_m / y))
	tmp = 0.0
	if (y <= -1.0)
		tmp = t_0;
	elseif (y <= 1.0)
		tmp = Float64(Float64(x_m - Float64(y * x_m)) * y);
	else
		tmp = t_0;
	end
	return Float64(x_s * tmp)
end
x\_m = abs(x);
x\_s = sign(x) * abs(1.0);
function tmp_2 = code(x_s, x_m, y)
	t_0 = x_m - (x_m / y);
	tmp = 0.0;
	if (y <= -1.0)
		tmp = t_0;
	elseif (y <= 1.0)
		tmp = (x_m - (y * x_m)) * y;
	else
		tmp = t_0;
	end
	tmp_2 = x_s * tmp;
end
x\_m = N[Abs[x], $MachinePrecision]
x\_s = N[With[{TMP1 = Abs[1.0], TMP2 = Sign[x]}, TMP1 * If[TMP2 == 0, 1, TMP2]], $MachinePrecision]
code[x$95$s_, x$95$m_, y_] := Block[{t$95$0 = N[(x$95$m - N[(x$95$m / y), $MachinePrecision]), $MachinePrecision]}, N[(x$95$s * If[LessEqual[y, -1.0], t$95$0, If[LessEqual[y, 1.0], N[(N[(x$95$m - N[(y * x$95$m), $MachinePrecision]), $MachinePrecision] * y), $MachinePrecision], t$95$0]]), $MachinePrecision]]
\begin{array}{l}
x\_m = \left|x\right|
\\
x\_s = \mathsf{copysign}\left(1, x\right)

\\
\begin{array}{l}
t_0 := x\_m - \frac{x\_m}{y}\\
x\_s \cdot \begin{array}{l}
\mathbf{if}\;y \leq -1:\\
\;\;\;\;t\_0\\

\mathbf{elif}\;y \leq 1:\\
\;\;\;\;\left(x\_m - y \cdot x\_m\right) \cdot y\\

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


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

    1. Initial program 80.1%

      \[\frac{x \cdot y}{y + 1} \]
    2. Add Preprocessing
    3. Taylor expanded in y around inf

      \[\leadsto \color{blue}{x + -1 \cdot \frac{x}{y}} \]
    4. Step-by-step derivation
      1. mul-1-negN/A

        \[\leadsto x + \color{blue}{\left(\mathsf{neg}\left(\frac{x}{y}\right)\right)} \]
      2. unsub-negN/A

        \[\leadsto \color{blue}{x - \frac{x}{y}} \]
      3. lower--.f64N/A

        \[\leadsto \color{blue}{x - \frac{x}{y}} \]
      4. lower-/.f6499.3

        \[\leadsto x - \color{blue}{\frac{x}{y}} \]
    5. Applied rewrites99.3%

      \[\leadsto \color{blue}{x - \frac{x}{y}} \]

    if -1 < y < 1

    1. Initial program 100.0%

      \[\frac{x \cdot y}{y + 1} \]
    2. Add Preprocessing
    3. Taylor expanded in y around 0

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

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

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

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

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

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

        \[\leadsto \left(x - \color{blue}{y \cdot x}\right) \cdot y \]
      7. lower-*.f6499.3

        \[\leadsto \left(x - \color{blue}{y \cdot x}\right) \cdot y \]
    5. Applied rewrites99.3%

      \[\leadsto \color{blue}{\left(x - y \cdot x\right) \cdot y} \]
  3. Recombined 2 regimes into one program.
  4. Add Preprocessing

Alternative 3: 51.2% accurate, 3.3× speedup?

\[\begin{array}{l} x\_m = \left|x\right| \\ x\_s = \mathsf{copysign}\left(1, x\right) \\ x\_s \cdot \left(y \cdot x\_m\right) \end{array} \]
x\_m = (fabs.f64 x)
x\_s = (copysign.f64 #s(literal 1 binary64) x)
(FPCore (x_s x_m y) :precision binary64 (* x_s (* y x_m)))
x\_m = fabs(x);
x\_s = copysign(1.0, x);
double code(double x_s, double x_m, double y) {
	return x_s * (y * x_m);
}
x\_m = abs(x)
x\_s = copysign(1.0d0, x)
real(8) function code(x_s, x_m, y)
    real(8), intent (in) :: x_s
    real(8), intent (in) :: x_m
    real(8), intent (in) :: y
    code = x_s * (y * x_m)
end function
x\_m = Math.abs(x);
x\_s = Math.copySign(1.0, x);
public static double code(double x_s, double x_m, double y) {
	return x_s * (y * x_m);
}
x\_m = math.fabs(x)
x\_s = math.copysign(1.0, x)
def code(x_s, x_m, y):
	return x_s * (y * x_m)
x\_m = abs(x)
x\_s = copysign(1.0, x)
function code(x_s, x_m, y)
	return Float64(x_s * Float64(y * x_m))
end
x\_m = abs(x);
x\_s = sign(x) * abs(1.0);
function tmp = code(x_s, x_m, y)
	tmp = x_s * (y * x_m);
end
x\_m = N[Abs[x], $MachinePrecision]
x\_s = N[With[{TMP1 = Abs[1.0], TMP2 = Sign[x]}, TMP1 * If[TMP2 == 0, 1, TMP2]], $MachinePrecision]
code[x$95$s_, x$95$m_, y_] := N[(x$95$s * N[(y * x$95$m), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
x\_m = \left|x\right|
\\
x\_s = \mathsf{copysign}\left(1, x\right)

\\
x\_s \cdot \left(y \cdot x\_m\right)
\end{array}
Derivation
  1. Initial program 90.4%

    \[\frac{x \cdot y}{y + 1} \]
  2. Add Preprocessing
  3. Taylor expanded in y around 0

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

      \[\leadsto \color{blue}{y \cdot x} \]
    2. lower-*.f6453.0

      \[\leadsto \color{blue}{y \cdot x} \]
  5. Applied rewrites53.0%

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

Developer Target 1: 99.9% accurate, 0.4× speedup?

\[\begin{array}{l} \\ \begin{array}{l} t_0 := \frac{x}{y \cdot y} - \left(\frac{x}{y} - x\right)\\ \mathbf{if}\;y < -3693.8482788297247:\\ \;\;\;\;t\_0\\ \mathbf{elif}\;y < 6799310503.41891:\\ \;\;\;\;\frac{x \cdot y}{y + 1}\\ \mathbf{else}:\\ \;\;\;\;t\_0\\ \end{array} \end{array} \]
(FPCore (x y)
 :precision binary64
 (let* ((t_0 (- (/ x (* y y)) (- (/ x y) x))))
   (if (< y -3693.8482788297247)
     t_0
     (if (< y 6799310503.41891) (/ (* x y) (+ y 1.0)) t_0))))
double code(double x, double y) {
	double t_0 = (x / (y * y)) - ((x / y) - x);
	double tmp;
	if (y < -3693.8482788297247) {
		tmp = t_0;
	} else if (y < 6799310503.41891) {
		tmp = (x * y) / (y + 1.0);
	} 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 = (x / (y * y)) - ((x / y) - x)
    if (y < (-3693.8482788297247d0)) then
        tmp = t_0
    else if (y < 6799310503.41891d0) then
        tmp = (x * y) / (y + 1.0d0)
    else
        tmp = t_0
    end if
    code = tmp
end function
public static double code(double x, double y) {
	double t_0 = (x / (y * y)) - ((x / y) - x);
	double tmp;
	if (y < -3693.8482788297247) {
		tmp = t_0;
	} else if (y < 6799310503.41891) {
		tmp = (x * y) / (y + 1.0);
	} else {
		tmp = t_0;
	}
	return tmp;
}
def code(x, y):
	t_0 = (x / (y * y)) - ((x / y) - x)
	tmp = 0
	if y < -3693.8482788297247:
		tmp = t_0
	elif y < 6799310503.41891:
		tmp = (x * y) / (y + 1.0)
	else:
		tmp = t_0
	return tmp
function code(x, y)
	t_0 = Float64(Float64(x / Float64(y * y)) - Float64(Float64(x / y) - x))
	tmp = 0.0
	if (y < -3693.8482788297247)
		tmp = t_0;
	elseif (y < 6799310503.41891)
		tmp = Float64(Float64(x * y) / Float64(y + 1.0));
	else
		tmp = t_0;
	end
	return tmp
end
function tmp_2 = code(x, y)
	t_0 = (x / (y * y)) - ((x / y) - x);
	tmp = 0.0;
	if (y < -3693.8482788297247)
		tmp = t_0;
	elseif (y < 6799310503.41891)
		tmp = (x * y) / (y + 1.0);
	else
		tmp = t_0;
	end
	tmp_2 = tmp;
end
code[x_, y_] := Block[{t$95$0 = N[(N[(x / N[(y * y), $MachinePrecision]), $MachinePrecision] - N[(N[(x / y), $MachinePrecision] - x), $MachinePrecision]), $MachinePrecision]}, If[Less[y, -3693.8482788297247], t$95$0, If[Less[y, 6799310503.41891], N[(N[(x * y), $MachinePrecision] / N[(y + 1.0), $MachinePrecision]), $MachinePrecision], t$95$0]]]
\begin{array}{l}

\\
\begin{array}{l}
t_0 := \frac{x}{y \cdot y} - \left(\frac{x}{y} - x\right)\\
\mathbf{if}\;y < -3693.8482788297247:\\
\;\;\;\;t\_0\\

\mathbf{elif}\;y < 6799310503.41891:\\
\;\;\;\;\frac{x \cdot y}{y + 1}\\

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


\end{array}
\end{array}

Reproduce

?
herbie shell --seed 2024248 
(FPCore (x y)
  :name "Diagrams.Trail:splitAtParam  from diagrams-lib-1.3.0.3, B"
  :precision binary64

  :alt
  (! :herbie-platform default (if (< y -36938482788297247/10000000000000) (- (/ x (* y y)) (- (/ x y) x)) (if (< y 679931050341891/100000) (/ (* x y) (+ y 1)) (- (/ x (* y y)) (- (/ x y) x)))))

  (/ (* x y) (+ y 1.0)))