Numeric.Signal.Multichannel:$cget from hsignal-0.2.7.1

Percentage Accurate: 97.6% → 91.6%
Time: 11.3s
Alternatives: 10
Speedup: 1.1×

Specification

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

\\
\frac{x}{y} \cdot \left(z - t\right) + t
\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 10 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: 97.6% accurate, 1.0× speedup?

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

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

Alternative 1: 91.6% accurate, 0.4× speedup?

\[\begin{array}{l} \\ \begin{array}{l} t_1 := x \cdot \frac{z - t}{y}\\ \mathbf{if}\;\frac{x}{y} \leq -9.8 \cdot 10^{+55}:\\ \;\;\;\;t\_1\\ \mathbf{elif}\;\frac{x}{y} \leq 10^{-9}:\\ \;\;\;\;t + \frac{z \cdot x}{y}\\ \mathbf{else}:\\ \;\;\;\;t\_1\\ \end{array} \end{array} \]
(FPCore (x y z t)
 :precision binary64
 (let* ((t_1 (* x (/ (- z t) y))))
   (if (<= (/ x y) -9.8e+55)
     t_1
     (if (<= (/ x y) 1e-9) (+ t (/ (* z x) y)) t_1))))
double code(double x, double y, double z, double t) {
	double t_1 = x * ((z - t) / y);
	double tmp;
	if ((x / y) <= -9.8e+55) {
		tmp = t_1;
	} else if ((x / y) <= 1e-9) {
		tmp = t + ((z * x) / y);
	} else {
		tmp = t_1;
	}
	return tmp;
}
real(8) function code(x, y, z, t)
    real(8), intent (in) :: x
    real(8), intent (in) :: y
    real(8), intent (in) :: z
    real(8), intent (in) :: t
    real(8) :: t_1
    real(8) :: tmp
    t_1 = x * ((z - t) / y)
    if ((x / y) <= (-9.8d+55)) then
        tmp = t_1
    else if ((x / y) <= 1d-9) then
        tmp = t + ((z * x) / y)
    else
        tmp = t_1
    end if
    code = tmp
end function
public static double code(double x, double y, double z, double t) {
	double t_1 = x * ((z - t) / y);
	double tmp;
	if ((x / y) <= -9.8e+55) {
		tmp = t_1;
	} else if ((x / y) <= 1e-9) {
		tmp = t + ((z * x) / y);
	} else {
		tmp = t_1;
	}
	return tmp;
}
def code(x, y, z, t):
	t_1 = x * ((z - t) / y)
	tmp = 0
	if (x / y) <= -9.8e+55:
		tmp = t_1
	elif (x / y) <= 1e-9:
		tmp = t + ((z * x) / y)
	else:
		tmp = t_1
	return tmp
function code(x, y, z, t)
	t_1 = Float64(x * Float64(Float64(z - t) / y))
	tmp = 0.0
	if (Float64(x / y) <= -9.8e+55)
		tmp = t_1;
	elseif (Float64(x / y) <= 1e-9)
		tmp = Float64(t + Float64(Float64(z * x) / y));
	else
		tmp = t_1;
	end
	return tmp
end
function tmp_2 = code(x, y, z, t)
	t_1 = x * ((z - t) / y);
	tmp = 0.0;
	if ((x / y) <= -9.8e+55)
		tmp = t_1;
	elseif ((x / y) <= 1e-9)
		tmp = t + ((z * x) / y);
	else
		tmp = t_1;
	end
	tmp_2 = tmp;
end
code[x_, y_, z_, t_] := Block[{t$95$1 = N[(x * N[(N[(z - t), $MachinePrecision] / y), $MachinePrecision]), $MachinePrecision]}, If[LessEqual[N[(x / y), $MachinePrecision], -9.8e+55], t$95$1, If[LessEqual[N[(x / y), $MachinePrecision], 1e-9], N[(t + N[(N[(z * x), $MachinePrecision] / y), $MachinePrecision]), $MachinePrecision], t$95$1]]]
\begin{array}{l}

\\
\begin{array}{l}
t_1 := x \cdot \frac{z - t}{y}\\
\mathbf{if}\;\frac{x}{y} \leq -9.8 \cdot 10^{+55}:\\
\;\;\;\;t\_1\\

\mathbf{elif}\;\frac{x}{y} \leq 10^{-9}:\\
\;\;\;\;t + \frac{z \cdot x}{y}\\

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


\end{array}
\end{array}
Derivation
  1. Split input into 2 regimes
  2. if (/.f64 x y) < -9.80000000000000029e55 or 1.00000000000000006e-9 < (/.f64 x y)

    1. Initial program 96.6%

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

      \[\leadsto \color{blue}{x \cdot \left(\frac{z}{y} - \frac{t}{y}\right)} \]
    4. Step-by-step derivation
      1. div-subN/A

        \[\leadsto x \cdot \color{blue}{\frac{z - t}{y}} \]
      2. associate-/l*N/A

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

        \[\leadsto \color{blue}{\frac{x \cdot \left(z - t\right)}{y}} \]
      4. lower-*.f64N/A

        \[\leadsto \frac{\color{blue}{x \cdot \left(z - t\right)}}{y} \]
      5. lower--.f6496.5

        \[\leadsto \frac{x \cdot \color{blue}{\left(z - t\right)}}{y} \]
    5. Applied rewrites96.5%

      \[\leadsto \color{blue}{\frac{x \cdot \left(z - t\right)}{y}} \]
    6. Step-by-step derivation
      1. Applied rewrites98.1%

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

      if -9.80000000000000029e55 < (/.f64 x y) < 1.00000000000000006e-9

      1. Initial program 97.6%

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

        \[\leadsto \color{blue}{\frac{x \cdot z}{y}} + t \]
      4. Step-by-step derivation
        1. lower-/.f64N/A

          \[\leadsto \color{blue}{\frac{x \cdot z}{y}} + t \]
        2. lower-*.f6497.2

          \[\leadsto \frac{\color{blue}{x \cdot z}}{y} + t \]
      5. Applied rewrites97.2%

        \[\leadsto \color{blue}{\frac{x \cdot z}{y}} + t \]
    7. Recombined 2 regimes into one program.
    8. Final simplification97.6%

      \[\leadsto \begin{array}{l} \mathbf{if}\;\frac{x}{y} \leq -9.8 \cdot 10^{+55}:\\ \;\;\;\;x \cdot \frac{z - t}{y}\\ \mathbf{elif}\;\frac{x}{y} \leq 10^{-9}:\\ \;\;\;\;t + \frac{z \cdot x}{y}\\ \mathbf{else}:\\ \;\;\;\;x \cdot \frac{z - t}{y}\\ \end{array} \]
    9. Add Preprocessing

    Alternative 2: 73.7% accurate, 0.3× speedup?

    \[\begin{array}{l} \\ \begin{array}{l} t_1 := \frac{x}{y} \cdot \left(-t\right)\\ \mathbf{if}\;\frac{x}{y} \leq -1 \cdot 10^{+227}:\\ \;\;\;\;t\_1\\ \mathbf{elif}\;\frac{x}{y} \leq -5 \cdot 10^{-37}:\\ \;\;\;\;z \cdot \frac{x}{y}\\ \mathbf{elif}\;\frac{x}{y} \leq 10^{+29}:\\ \;\;\;\;\mathsf{fma}\left(\frac{z}{y}, x, t\right)\\ \mathbf{else}:\\ \;\;\;\;t\_1\\ \end{array} \end{array} \]
    (FPCore (x y z t)
     :precision binary64
     (let* ((t_1 (* (/ x y) (- t))))
       (if (<= (/ x y) -1e+227)
         t_1
         (if (<= (/ x y) -5e-37)
           (* z (/ x y))
           (if (<= (/ x y) 1e+29) (fma (/ z y) x t) t_1)))))
    double code(double x, double y, double z, double t) {
    	double t_1 = (x / y) * -t;
    	double tmp;
    	if ((x / y) <= -1e+227) {
    		tmp = t_1;
    	} else if ((x / y) <= -5e-37) {
    		tmp = z * (x / y);
    	} else if ((x / y) <= 1e+29) {
    		tmp = fma((z / y), x, t);
    	} else {
    		tmp = t_1;
    	}
    	return tmp;
    }
    
    function code(x, y, z, t)
    	t_1 = Float64(Float64(x / y) * Float64(-t))
    	tmp = 0.0
    	if (Float64(x / y) <= -1e+227)
    		tmp = t_1;
    	elseif (Float64(x / y) <= -5e-37)
    		tmp = Float64(z * Float64(x / y));
    	elseif (Float64(x / y) <= 1e+29)
    		tmp = fma(Float64(z / y), x, t);
    	else
    		tmp = t_1;
    	end
    	return tmp
    end
    
    code[x_, y_, z_, t_] := Block[{t$95$1 = N[(N[(x / y), $MachinePrecision] * (-t)), $MachinePrecision]}, If[LessEqual[N[(x / y), $MachinePrecision], -1e+227], t$95$1, If[LessEqual[N[(x / y), $MachinePrecision], -5e-37], N[(z * N[(x / y), $MachinePrecision]), $MachinePrecision], If[LessEqual[N[(x / y), $MachinePrecision], 1e+29], N[(N[(z / y), $MachinePrecision] * x + t), $MachinePrecision], t$95$1]]]]
    
    \begin{array}{l}
    
    \\
    \begin{array}{l}
    t_1 := \frac{x}{y} \cdot \left(-t\right)\\
    \mathbf{if}\;\frac{x}{y} \leq -1 \cdot 10^{+227}:\\
    \;\;\;\;t\_1\\
    
    \mathbf{elif}\;\frac{x}{y} \leq -5 \cdot 10^{-37}:\\
    \;\;\;\;z \cdot \frac{x}{y}\\
    
    \mathbf{elif}\;\frac{x}{y} \leq 10^{+29}:\\
    \;\;\;\;\mathsf{fma}\left(\frac{z}{y}, x, t\right)\\
    
    \mathbf{else}:\\
    \;\;\;\;t\_1\\
    
    
    \end{array}
    \end{array}
    
    Derivation
    1. Split input into 3 regimes
    2. if (/.f64 x y) < -1.0000000000000001e227 or 9.99999999999999914e28 < (/.f64 x y)

      1. Initial program 95.3%

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

        \[\leadsto \color{blue}{x \cdot \left(\frac{z}{y} - \frac{t}{y}\right)} \]
      4. Step-by-step derivation
        1. div-subN/A

          \[\leadsto x \cdot \color{blue}{\frac{z - t}{y}} \]
        2. associate-/l*N/A

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

          \[\leadsto \color{blue}{\frac{x \cdot \left(z - t\right)}{y}} \]
        4. lower-*.f64N/A

          \[\leadsto \frac{\color{blue}{x \cdot \left(z - t\right)}}{y} \]
        5. lower--.f6495.8

          \[\leadsto \frac{x \cdot \color{blue}{\left(z - t\right)}}{y} \]
      5. Applied rewrites95.8%

        \[\leadsto \color{blue}{\frac{x \cdot \left(z - t\right)}{y}} \]
      6. Taylor expanded in z around 0

        \[\leadsto \frac{x \cdot \left(-1 \cdot t\right)}{y} \]
      7. Step-by-step derivation
        1. Applied rewrites53.6%

          \[\leadsto \frac{x \cdot \left(-t\right)}{y} \]
        2. Step-by-step derivation
          1. Applied rewrites57.9%

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

          if -1.0000000000000001e227 < (/.f64 x y) < -4.9999999999999997e-37

          1. Initial program 99.7%

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

            \[\leadsto \color{blue}{\frac{x \cdot z}{y}} \]
          4. Step-by-step derivation
            1. lower-/.f64N/A

              \[\leadsto \color{blue}{\frac{x \cdot z}{y}} \]
            2. lower-*.f6445.4

              \[\leadsto \frac{\color{blue}{x \cdot z}}{y} \]
          5. Applied rewrites45.4%

            \[\leadsto \color{blue}{\frac{x \cdot z}{y}} \]
          6. Step-by-step derivation
            1. Applied rewrites50.5%

              \[\leadsto \frac{x}{y} \cdot \color{blue}{z} \]

            if -4.9999999999999997e-37 < (/.f64 x y) < 9.99999999999999914e28

            1. Initial program 98.3%

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

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

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

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

                \[\leadsto \color{blue}{\frac{x \cdot \left(z - t\right)}{y}} + t \]
              5. associate-/l*N/A

                \[\leadsto \color{blue}{x \cdot \frac{z - t}{y}} + t \]
              6. *-commutativeN/A

                \[\leadsto \color{blue}{\frac{z - t}{y} \cdot x} + t \]
              7. lower-fma.f64N/A

                \[\leadsto \color{blue}{\mathsf{fma}\left(\frac{z - t}{y}, x, t\right)} \]
              8. lower-/.f6492.7

                \[\leadsto \mathsf{fma}\left(\color{blue}{\frac{z - t}{y}}, x, t\right) \]
            4. Applied rewrites92.7%

              \[\leadsto \color{blue}{\mathsf{fma}\left(\frac{z - t}{y}, x, t\right)} \]
            5. Taylor expanded in z around inf

              \[\leadsto \mathsf{fma}\left(\color{blue}{\frac{z}{y}}, x, t\right) \]
            6. Step-by-step derivation
              1. lower-/.f6492.6

                \[\leadsto \mathsf{fma}\left(\color{blue}{\frac{z}{y}}, x, t\right) \]
            7. Applied rewrites92.6%

              \[\leadsto \mathsf{fma}\left(\color{blue}{\frac{z}{y}}, x, t\right) \]
          7. Recombined 3 regimes into one program.
          8. Final simplification73.7%

            \[\leadsto \begin{array}{l} \mathbf{if}\;\frac{x}{y} \leq -1 \cdot 10^{+227}:\\ \;\;\;\;\frac{x}{y} \cdot \left(-t\right)\\ \mathbf{elif}\;\frac{x}{y} \leq -5 \cdot 10^{-37}:\\ \;\;\;\;z \cdot \frac{x}{y}\\ \mathbf{elif}\;\frac{x}{y} \leq 10^{+29}:\\ \;\;\;\;\mathsf{fma}\left(\frac{z}{y}, x, t\right)\\ \mathbf{else}:\\ \;\;\;\;\frac{x}{y} \cdot \left(-t\right)\\ \end{array} \]
          9. Add Preprocessing

          Developer Target 1: 97.4% accurate, 0.7× speedup?

          \[\begin{array}{l} \\ \begin{array}{l} t_1 := \frac{x}{y} \cdot \left(z - t\right) + t\\ \mathbf{if}\;z < 2.759456554562692 \cdot 10^{-282}:\\ \;\;\;\;t\_1\\ \mathbf{elif}\;z < 2.326994450874436 \cdot 10^{-110}:\\ \;\;\;\;x \cdot \frac{z - t}{y} + t\\ \mathbf{else}:\\ \;\;\;\;t\_1\\ \end{array} \end{array} \]
          (FPCore (x y z t)
           :precision binary64
           (let* ((t_1 (+ (* (/ x y) (- z t)) t)))
             (if (< z 2.759456554562692e-282)
               t_1
               (if (< z 2.326994450874436e-110) (+ (* x (/ (- z t) y)) t) t_1))))
          double code(double x, double y, double z, double t) {
          	double t_1 = ((x / y) * (z - t)) + t;
          	double tmp;
          	if (z < 2.759456554562692e-282) {
          		tmp = t_1;
          	} else if (z < 2.326994450874436e-110) {
          		tmp = (x * ((z - t) / y)) + t;
          	} else {
          		tmp = t_1;
          	}
          	return tmp;
          }
          
          real(8) function code(x, y, z, t)
              real(8), intent (in) :: x
              real(8), intent (in) :: y
              real(8), intent (in) :: z
              real(8), intent (in) :: t
              real(8) :: t_1
              real(8) :: tmp
              t_1 = ((x / y) * (z - t)) + t
              if (z < 2.759456554562692d-282) then
                  tmp = t_1
              else if (z < 2.326994450874436d-110) then
                  tmp = (x * ((z - t) / y)) + t
              else
                  tmp = t_1
              end if
              code = tmp
          end function
          
          public static double code(double x, double y, double z, double t) {
          	double t_1 = ((x / y) * (z - t)) + t;
          	double tmp;
          	if (z < 2.759456554562692e-282) {
          		tmp = t_1;
          	} else if (z < 2.326994450874436e-110) {
          		tmp = (x * ((z - t) / y)) + t;
          	} else {
          		tmp = t_1;
          	}
          	return tmp;
          }
          
          def code(x, y, z, t):
          	t_1 = ((x / y) * (z - t)) + t
          	tmp = 0
          	if z < 2.759456554562692e-282:
          		tmp = t_1
          	elif z < 2.326994450874436e-110:
          		tmp = (x * ((z - t) / y)) + t
          	else:
          		tmp = t_1
          	return tmp
          
          function code(x, y, z, t)
          	t_1 = Float64(Float64(Float64(x / y) * Float64(z - t)) + t)
          	tmp = 0.0
          	if (z < 2.759456554562692e-282)
          		tmp = t_1;
          	elseif (z < 2.326994450874436e-110)
          		tmp = Float64(Float64(x * Float64(Float64(z - t) / y)) + t);
          	else
          		tmp = t_1;
          	end
          	return tmp
          end
          
          function tmp_2 = code(x, y, z, t)
          	t_1 = ((x / y) * (z - t)) + t;
          	tmp = 0.0;
          	if (z < 2.759456554562692e-282)
          		tmp = t_1;
          	elseif (z < 2.326994450874436e-110)
          		tmp = (x * ((z - t) / y)) + t;
          	else
          		tmp = t_1;
          	end
          	tmp_2 = tmp;
          end
          
          code[x_, y_, z_, t_] := Block[{t$95$1 = N[(N[(N[(x / y), $MachinePrecision] * N[(z - t), $MachinePrecision]), $MachinePrecision] + t), $MachinePrecision]}, If[Less[z, 2.759456554562692e-282], t$95$1, If[Less[z, 2.326994450874436e-110], N[(N[(x * N[(N[(z - t), $MachinePrecision] / y), $MachinePrecision]), $MachinePrecision] + t), $MachinePrecision], t$95$1]]]
          
          \begin{array}{l}
          
          \\
          \begin{array}{l}
          t_1 := \frac{x}{y} \cdot \left(z - t\right) + t\\
          \mathbf{if}\;z < 2.759456554562692 \cdot 10^{-282}:\\
          \;\;\;\;t\_1\\
          
          \mathbf{elif}\;z < 2.326994450874436 \cdot 10^{-110}:\\
          \;\;\;\;x \cdot \frac{z - t}{y} + t\\
          
          \mathbf{else}:\\
          \;\;\;\;t\_1\\
          
          
          \end{array}
          \end{array}
          

          Reproduce

          ?
          herbie shell --seed 2024228 
          (FPCore (x y z t)
            :name "Numeric.Signal.Multichannel:$cget from hsignal-0.2.7.1"
            :precision binary64
          
            :alt
            (! :herbie-platform default (if (< z 689864138640673/250000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000) (+ (* (/ x y) (- z t)) t) (if (< z 581748612718609/25000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000) (+ (* x (/ (- z t) y)) t) (+ (* (/ x y) (- z t)) t))))
          
            (+ (* (/ x y) (- z t)) t))