Statistics.Distribution.Poisson.Internal:probability from math-functions-0.1.5.2

Percentage Accurate: 100.0% → 100.0%
Time: 6.0s
Alternatives: 4
Speedup: 1.0×

Specification

?
\[\begin{array}{l} \\ e^{\left(x + y \cdot \log y\right) - z} \end{array} \]
(FPCore (x y z) :precision binary64 (exp (- (+ x (* y (log y))) z)))
double code(double x, double y, double z) {
	return exp(((x + (y * log(y))) - z));
}
real(8) function code(x, y, z)
    real(8), intent (in) :: x
    real(8), intent (in) :: y
    real(8), intent (in) :: z
    code = exp(((x + (y * log(y))) - z))
end function
public static double code(double x, double y, double z) {
	return Math.exp(((x + (y * Math.log(y))) - z));
}
def code(x, y, z):
	return math.exp(((x + (y * math.log(y))) - z))
function code(x, y, z)
	return exp(Float64(Float64(x + Float64(y * log(y))) - z))
end
function tmp = code(x, y, z)
	tmp = exp(((x + (y * log(y))) - z));
end
code[x_, y_, z_] := N[Exp[N[(N[(x + N[(y * N[Log[y], $MachinePrecision]), $MachinePrecision]), $MachinePrecision] - z), $MachinePrecision]], $MachinePrecision]
\begin{array}{l}

\\
e^{\left(x + y \cdot \log y\right) - z}
\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: 100.0% accurate, 1.0× speedup?

\[\begin{array}{l} \\ e^{\left(x + y \cdot \log y\right) - z} \end{array} \]
(FPCore (x y z) :precision binary64 (exp (- (+ x (* y (log y))) z)))
double code(double x, double y, double z) {
	return exp(((x + (y * log(y))) - z));
}
real(8) function code(x, y, z)
    real(8), intent (in) :: x
    real(8), intent (in) :: y
    real(8), intent (in) :: z
    code = exp(((x + (y * log(y))) - z))
end function
public static double code(double x, double y, double z) {
	return Math.exp(((x + (y * Math.log(y))) - z));
}
def code(x, y, z):
	return math.exp(((x + (y * math.log(y))) - z))
function code(x, y, z)
	return exp(Float64(Float64(x + Float64(y * log(y))) - z))
end
function tmp = code(x, y, z)
	tmp = exp(((x + (y * log(y))) - z));
end
code[x_, y_, z_] := N[Exp[N[(N[(x + N[(y * N[Log[y], $MachinePrecision]), $MachinePrecision]), $MachinePrecision] - z), $MachinePrecision]], $MachinePrecision]
\begin{array}{l}

\\
e^{\left(x + y \cdot \log y\right) - z}
\end{array}

Alternative 1: 100.0% accurate, 1.0× speedup?

\[\begin{array}{l} \\ e^{\left(\log y \cdot y + x\right) - z} \end{array} \]
(FPCore (x y z) :precision binary64 (exp (- (+ (* (log y) y) x) z)))
double code(double x, double y, double z) {
	return exp((((log(y) * y) + x) - z));
}
real(8) function code(x, y, z)
    real(8), intent (in) :: x
    real(8), intent (in) :: y
    real(8), intent (in) :: z
    code = exp((((log(y) * y) + x) - z))
end function
public static double code(double x, double y, double z) {
	return Math.exp((((Math.log(y) * y) + x) - z));
}
def code(x, y, z):
	return math.exp((((math.log(y) * y) + x) - z))
function code(x, y, z)
	return exp(Float64(Float64(Float64(log(y) * y) + x) - z))
end
function tmp = code(x, y, z)
	tmp = exp((((log(y) * y) + x) - z));
end
code[x_, y_, z_] := N[Exp[N[(N[(N[(N[Log[y], $MachinePrecision] * y), $MachinePrecision] + x), $MachinePrecision] - z), $MachinePrecision]], $MachinePrecision]
\begin{array}{l}

\\
e^{\left(\log y \cdot y + x\right) - z}
\end{array}
Derivation
  1. Initial program 100.0%

    \[e^{\left(x + y \cdot \log y\right) - z} \]
  2. Add Preprocessing
  3. Final simplification100.0%

    \[\leadsto e^{\left(\log y \cdot y + x\right) - z} \]
  4. Add Preprocessing

Alternative 2: 87.9% accurate, 0.4× speedup?

\[\begin{array}{l} \\ \begin{array}{l} t_0 := \log y \cdot y\\ t_1 := e^{t\_0}\\ \mathbf{if}\;t\_0 \leq 5 \cdot 10^{+54}:\\ \;\;\;\;e^{x - z}\\ \mathbf{elif}\;t\_0 \leq 5 \cdot 10^{+141}:\\ \;\;\;\;t\_1\\ \mathbf{elif}\;t\_0 \leq 2 \cdot 10^{+204}:\\ \;\;\;\;e^{\frac{\mathsf{fma}\left(-z, z, x \cdot x\right)}{z + x}}\\ \mathbf{else}:\\ \;\;\;\;t\_1\\ \end{array} \end{array} \]
(FPCore (x y z)
 :precision binary64
 (let* ((t_0 (* (log y) y)) (t_1 (exp t_0)))
   (if (<= t_0 5e+54)
     (exp (- x z))
     (if (<= t_0 5e+141)
       t_1
       (if (<= t_0 2e+204) (exp (/ (fma (- z) z (* x x)) (+ z x))) t_1)))))
double code(double x, double y, double z) {
	double t_0 = log(y) * y;
	double t_1 = exp(t_0);
	double tmp;
	if (t_0 <= 5e+54) {
		tmp = exp((x - z));
	} else if (t_0 <= 5e+141) {
		tmp = t_1;
	} else if (t_0 <= 2e+204) {
		tmp = exp((fma(-z, z, (x * x)) / (z + x)));
	} else {
		tmp = t_1;
	}
	return tmp;
}
function code(x, y, z)
	t_0 = Float64(log(y) * y)
	t_1 = exp(t_0)
	tmp = 0.0
	if (t_0 <= 5e+54)
		tmp = exp(Float64(x - z));
	elseif (t_0 <= 5e+141)
		tmp = t_1;
	elseif (t_0 <= 2e+204)
		tmp = exp(Float64(fma(Float64(-z), z, Float64(x * x)) / Float64(z + x)));
	else
		tmp = t_1;
	end
	return tmp
end
code[x_, y_, z_] := Block[{t$95$0 = N[(N[Log[y], $MachinePrecision] * y), $MachinePrecision]}, Block[{t$95$1 = N[Exp[t$95$0], $MachinePrecision]}, If[LessEqual[t$95$0, 5e+54], N[Exp[N[(x - z), $MachinePrecision]], $MachinePrecision], If[LessEqual[t$95$0, 5e+141], t$95$1, If[LessEqual[t$95$0, 2e+204], N[Exp[N[(N[((-z) * z + N[(x * x), $MachinePrecision]), $MachinePrecision] / N[(z + x), $MachinePrecision]), $MachinePrecision]], $MachinePrecision], t$95$1]]]]]
\begin{array}{l}

\\
\begin{array}{l}
t_0 := \log y \cdot y\\
t_1 := e^{t\_0}\\
\mathbf{if}\;t\_0 \leq 5 \cdot 10^{+54}:\\
\;\;\;\;e^{x - z}\\

\mathbf{elif}\;t\_0 \leq 5 \cdot 10^{+141}:\\
\;\;\;\;t\_1\\

\mathbf{elif}\;t\_0 \leq 2 \cdot 10^{+204}:\\
\;\;\;\;e^{\frac{\mathsf{fma}\left(-z, z, x \cdot x\right)}{z + x}}\\

\mathbf{else}:\\
\;\;\;\;t\_1\\


\end{array}
\end{array}
Derivation
  1. Split input into 3 regimes
  2. if (*.f64 y (log.f64 y)) < 5.00000000000000005e54

    1. Initial program 100.0%

      \[e^{\left(x + y \cdot \log y\right) - z} \]
    2. Add Preprocessing
    3. Taylor expanded in y around 0

      \[\leadsto e^{\color{blue}{x - z}} \]
    4. Step-by-step derivation
      1. lower--.f6494.3

        \[\leadsto e^{\color{blue}{x - z}} \]
    5. Applied rewrites94.3%

      \[\leadsto e^{\color{blue}{x - z}} \]

    if 5.00000000000000005e54 < (*.f64 y (log.f64 y)) < 5.00000000000000025e141 or 1.99999999999999998e204 < (*.f64 y (log.f64 y))

    1. Initial program 100.0%

      \[e^{\left(x + y \cdot \log y\right) - z} \]
    2. Add Preprocessing
    3. Taylor expanded in y around inf

      \[\leadsto e^{\color{blue}{-1 \cdot \left(y \cdot \log \left(\frac{1}{y}\right)\right)}} \]
    4. Step-by-step derivation
      1. mul-1-negN/A

        \[\leadsto e^{\color{blue}{\mathsf{neg}\left(y \cdot \log \left(\frac{1}{y}\right)\right)}} \]
      2. *-commutativeN/A

        \[\leadsto e^{\mathsf{neg}\left(\color{blue}{\log \left(\frac{1}{y}\right) \cdot y}\right)} \]
      3. distribute-lft-neg-inN/A

        \[\leadsto e^{\color{blue}{\left(\mathsf{neg}\left(\log \left(\frac{1}{y}\right)\right)\right) \cdot y}} \]
      4. log-recN/A

        \[\leadsto e^{\left(\mathsf{neg}\left(\color{blue}{\left(\mathsf{neg}\left(\log y\right)\right)}\right)\right) \cdot y} \]
      5. remove-double-negN/A

        \[\leadsto e^{\color{blue}{\log y} \cdot y} \]
      6. lower-*.f64N/A

        \[\leadsto e^{\color{blue}{\log y \cdot y}} \]
      7. lower-log.f6488.4

        \[\leadsto e^{\color{blue}{\log y} \cdot y} \]
    5. Applied rewrites88.4%

      \[\leadsto e^{\color{blue}{\log y \cdot y}} \]

    if 5.00000000000000025e141 < (*.f64 y (log.f64 y)) < 1.99999999999999998e204

    1. Initial program 100.0%

      \[e^{\left(x + y \cdot \log y\right) - z} \]
    2. Add Preprocessing
    3. Taylor expanded in y around 0

      \[\leadsto e^{\color{blue}{x - z}} \]
    4. Step-by-step derivation
      1. lower--.f6481.5

        \[\leadsto e^{\color{blue}{x - z}} \]
    5. Applied rewrites81.5%

      \[\leadsto e^{\color{blue}{x - z}} \]
    6. Step-by-step derivation
      1. Applied rewrites81.5%

        \[\leadsto e^{\frac{\mathsf{fma}\left(-z, z, x \cdot x\right)}{\color{blue}{z + x}}} \]
    7. Recombined 3 regimes into one program.
    8. Final simplification91.3%

      \[\leadsto \begin{array}{l} \mathbf{if}\;\log y \cdot y \leq 5 \cdot 10^{+54}:\\ \;\;\;\;e^{x - z}\\ \mathbf{elif}\;\log y \cdot y \leq 5 \cdot 10^{+141}:\\ \;\;\;\;e^{\log y \cdot y}\\ \mathbf{elif}\;\log y \cdot y \leq 2 \cdot 10^{+204}:\\ \;\;\;\;e^{\frac{\mathsf{fma}\left(-z, z, x \cdot x\right)}{z + x}}\\ \mathbf{else}:\\ \;\;\;\;e^{\log y \cdot y}\\ \end{array} \]
    9. Add Preprocessing

    Alternative 3: 79.6% accurate, 2.0× speedup?

    \[\begin{array}{l} \\ e^{x - z} \end{array} \]
    (FPCore (x y z) :precision binary64 (exp (- x z)))
    double code(double x, double y, double z) {
    	return exp((x - z));
    }
    
    real(8) function code(x, y, z)
        real(8), intent (in) :: x
        real(8), intent (in) :: y
        real(8), intent (in) :: z
        code = exp((x - z))
    end function
    
    public static double code(double x, double y, double z) {
    	return Math.exp((x - z));
    }
    
    def code(x, y, z):
    	return math.exp((x - z))
    
    function code(x, y, z)
    	return exp(Float64(x - z))
    end
    
    function tmp = code(x, y, z)
    	tmp = exp((x - z));
    end
    
    code[x_, y_, z_] := N[Exp[N[(x - z), $MachinePrecision]], $MachinePrecision]
    
    \begin{array}{l}
    
    \\
    e^{x - z}
    \end{array}
    
    Derivation
    1. Initial program 100.0%

      \[e^{\left(x + y \cdot \log y\right) - z} \]
    2. Add Preprocessing
    3. Taylor expanded in y around 0

      \[\leadsto e^{\color{blue}{x - z}} \]
    4. Step-by-step derivation
      1. lower--.f6479.5

        \[\leadsto e^{\color{blue}{x - z}} \]
    5. Applied rewrites79.5%

      \[\leadsto e^{\color{blue}{x - z}} \]
    6. Add Preprocessing

    Alternative 4: 52.8% accurate, 2.1× speedup?

    \[\begin{array}{l} \\ e^{-z} \end{array} \]
    (FPCore (x y z) :precision binary64 (exp (- z)))
    double code(double x, double y, double z) {
    	return exp(-z);
    }
    
    real(8) function code(x, y, z)
        real(8), intent (in) :: x
        real(8), intent (in) :: y
        real(8), intent (in) :: z
        code = exp(-z)
    end function
    
    public static double code(double x, double y, double z) {
    	return Math.exp(-z);
    }
    
    def code(x, y, z):
    	return math.exp(-z)
    
    function code(x, y, z)
    	return exp(Float64(-z))
    end
    
    function tmp = code(x, y, z)
    	tmp = exp(-z);
    end
    
    code[x_, y_, z_] := N[Exp[(-z)], $MachinePrecision]
    
    \begin{array}{l}
    
    \\
    e^{-z}
    \end{array}
    
    Derivation
    1. Initial program 100.0%

      \[e^{\left(x + y \cdot \log y\right) - z} \]
    2. Add Preprocessing
    3. Taylor expanded in z around inf

      \[\leadsto e^{\color{blue}{-1 \cdot z}} \]
    4. Step-by-step derivation
      1. mul-1-negN/A

        \[\leadsto e^{\color{blue}{\mathsf{neg}\left(z\right)}} \]
      2. lower-neg.f6452.2

        \[\leadsto e^{\color{blue}{-z}} \]
    5. Applied rewrites52.2%

      \[\leadsto e^{\color{blue}{-z}} \]
    6. Add Preprocessing

    Developer Target 1: 100.0% accurate, 1.0× speedup?

    \[\begin{array}{l} \\ e^{\left(x - z\right) + \log y \cdot y} \end{array} \]
    (FPCore (x y z) :precision binary64 (exp (+ (- x z) (* (log y) y))))
    double code(double x, double y, double z) {
    	return exp(((x - z) + (log(y) * y)));
    }
    
    real(8) function code(x, y, z)
        real(8), intent (in) :: x
        real(8), intent (in) :: y
        real(8), intent (in) :: z
        code = exp(((x - z) + (log(y) * y)))
    end function
    
    public static double code(double x, double y, double z) {
    	return Math.exp(((x - z) + (Math.log(y) * y)));
    }
    
    def code(x, y, z):
    	return math.exp(((x - z) + (math.log(y) * y)))
    
    function code(x, y, z)
    	return exp(Float64(Float64(x - z) + Float64(log(y) * y)))
    end
    
    function tmp = code(x, y, z)
    	tmp = exp(((x - z) + (log(y) * y)));
    end
    
    code[x_, y_, z_] := N[Exp[N[(N[(x - z), $MachinePrecision] + N[(N[Log[y], $MachinePrecision] * y), $MachinePrecision]), $MachinePrecision]], $MachinePrecision]
    
    \begin{array}{l}
    
    \\
    e^{\left(x - z\right) + \log y \cdot y}
    \end{array}
    

    Reproduce

    ?
    herbie shell --seed 2024249 
    (FPCore (x y z)
      :name "Statistics.Distribution.Poisson.Internal:probability from math-functions-0.1.5.2"
      :precision binary64
    
      :alt
      (! :herbie-platform default (exp (+ (- x z) (* (log y) y))))
    
      (exp (- (+ x (* y (log y))) z)))