Language.Haskell.HsColour.ColourHighlight:unbase from hscolour-1.23

Percentage Accurate: 99.9% → 99.9%
Time: 5.0s
Alternatives: 5
Speedup: 1.3×

Specification

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

\\
\left(x \cdot y + z\right) \cdot y + 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 5 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: 99.9% accurate, 1.0× speedup?

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

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

Alternative 1: 99.9% accurate, 1.3× speedup?

\[\begin{array}{l} \\ \mathsf{fma}\left(\mathsf{fma}\left(y, x, z\right), y, t\right) \end{array} \]
(FPCore (x y z t) :precision binary64 (fma (fma y x z) y t))
double code(double x, double y, double z, double t) {
	return fma(fma(y, x, z), y, t);
}
function code(x, y, z, t)
	return fma(fma(y, x, z), y, t)
end
code[x_, y_, z_, t_] := N[(N[(y * x + z), $MachinePrecision] * y + t), $MachinePrecision]
\begin{array}{l}

\\
\mathsf{fma}\left(\mathsf{fma}\left(y, x, z\right), y, t\right)
\end{array}
Derivation
  1. Initial program 100.0%

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

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

      \[\leadsto \color{blue}{\left(x \cdot y + z\right) \cdot y} + t \]
    3. lower-fma.f64100.0

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

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

      \[\leadsto \mathsf{fma}\left(\color{blue}{x \cdot y} + z, y, t\right) \]
    6. *-commutativeN/A

      \[\leadsto \mathsf{fma}\left(\color{blue}{y \cdot x} + z, y, t\right) \]
    7. lower-fma.f64100.0

      \[\leadsto \mathsf{fma}\left(\color{blue}{\mathsf{fma}\left(y, x, z\right)}, y, t\right) \]
  4. Applied rewrites100.0%

    \[\leadsto \color{blue}{\mathsf{fma}\left(\mathsf{fma}\left(y, x, z\right), y, t\right)} \]
  5. Add Preprocessing

Alternative 2: 90.8% accurate, 0.3× speedup?

\[\begin{array}{l} \\ \begin{array}{l} t_1 := \left(x \cdot y + z\right) \cdot y\\ \mathbf{if}\;t\_1 \leq -5 \cdot 10^{+138} \lor \neg \left(t\_1 \leq 5 \cdot 10^{+154}\right):\\ \;\;\;\;\mathsf{fma}\left(y, x, z\right) \cdot y\\ \mathbf{else}:\\ \;\;\;\;\mathsf{fma}\left(z, y, t\right)\\ \end{array} \end{array} \]
(FPCore (x y z t)
 :precision binary64
 (let* ((t_1 (* (+ (* x y) z) y)))
   (if (or (<= t_1 -5e+138) (not (<= t_1 5e+154)))
     (* (fma y x z) y)
     (fma z y t))))
double code(double x, double y, double z, double t) {
	double t_1 = ((x * y) + z) * y;
	double tmp;
	if ((t_1 <= -5e+138) || !(t_1 <= 5e+154)) {
		tmp = fma(y, x, z) * y;
	} else {
		tmp = fma(z, y, t);
	}
	return tmp;
}
function code(x, y, z, t)
	t_1 = Float64(Float64(Float64(x * y) + z) * y)
	tmp = 0.0
	if ((t_1 <= -5e+138) || !(t_1 <= 5e+154))
		tmp = Float64(fma(y, x, z) * y);
	else
		tmp = fma(z, y, t);
	end
	return tmp
end
code[x_, y_, z_, t_] := Block[{t$95$1 = N[(N[(N[(x * y), $MachinePrecision] + z), $MachinePrecision] * y), $MachinePrecision]}, If[Or[LessEqual[t$95$1, -5e+138], N[Not[LessEqual[t$95$1, 5e+154]], $MachinePrecision]], N[(N[(y * x + z), $MachinePrecision] * y), $MachinePrecision], N[(z * y + t), $MachinePrecision]]]
\begin{array}{l}

\\
\begin{array}{l}
t_1 := \left(x \cdot y + z\right) \cdot y\\
\mathbf{if}\;t\_1 \leq -5 \cdot 10^{+138} \lor \neg \left(t\_1 \leq 5 \cdot 10^{+154}\right):\\
\;\;\;\;\mathsf{fma}\left(y, x, z\right) \cdot y\\

\mathbf{else}:\\
\;\;\;\;\mathsf{fma}\left(z, y, t\right)\\


\end{array}
\end{array}
Derivation
  1. Split input into 2 regimes
  2. if (*.f64 (+.f64 (*.f64 x y) z) y) < -5.00000000000000016e138 or 5.00000000000000004e154 < (*.f64 (+.f64 (*.f64 x y) z) y)

    1. Initial program 100.0%

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

      \[\leadsto \color{blue}{{y}^{2} \cdot \left(x + \frac{z}{y}\right)} \]
    4. Step-by-step derivation
      1. +-commutativeN/A

        \[\leadsto {y}^{2} \cdot \color{blue}{\left(\frac{z}{y} + x\right)} \]
      2. distribute-lft-inN/A

        \[\leadsto \color{blue}{{y}^{2} \cdot \frac{z}{y} + {y}^{2} \cdot x} \]
    5. Applied rewrites96.3%

      \[\leadsto \color{blue}{\mathsf{fma}\left(y, x, z\right) \cdot y} \]

    if -5.00000000000000016e138 < (*.f64 (+.f64 (*.f64 x y) z) y) < 5.00000000000000004e154

    1. Initial program 100.0%

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

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

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

        \[\leadsto \color{blue}{z \cdot y} + t \]
      3. lower-fma.f6490.7

        \[\leadsto \color{blue}{\mathsf{fma}\left(z, y, t\right)} \]
    5. Applied rewrites90.7%

      \[\leadsto \color{blue}{\mathsf{fma}\left(z, y, t\right)} \]
  3. Recombined 2 regimes into one program.
  4. Final simplification93.4%

    \[\leadsto \begin{array}{l} \mathbf{if}\;\left(x \cdot y + z\right) \cdot y \leq -5 \cdot 10^{+138} \lor \neg \left(\left(x \cdot y + z\right) \cdot y \leq 5 \cdot 10^{+154}\right):\\ \;\;\;\;\mathsf{fma}\left(y, x, z\right) \cdot y\\ \mathbf{else}:\\ \;\;\;\;\mathsf{fma}\left(z, y, t\right)\\ \end{array} \]
  5. Add Preprocessing

Alternative 3: 79.5% accurate, 0.7× speedup?

\[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;y \leq -6.5 \cdot 10^{+93} \lor \neg \left(y \leq 7.2 \cdot 10^{+110}\right):\\ \;\;\;\;\left(x \cdot y\right) \cdot y\\ \mathbf{else}:\\ \;\;\;\;\mathsf{fma}\left(z, y, t\right)\\ \end{array} \end{array} \]
(FPCore (x y z t)
 :precision binary64
 (if (or (<= y -6.5e+93) (not (<= y 7.2e+110))) (* (* x y) y) (fma z y t)))
double code(double x, double y, double z, double t) {
	double tmp;
	if ((y <= -6.5e+93) || !(y <= 7.2e+110)) {
		tmp = (x * y) * y;
	} else {
		tmp = fma(z, y, t);
	}
	return tmp;
}
function code(x, y, z, t)
	tmp = 0.0
	if ((y <= -6.5e+93) || !(y <= 7.2e+110))
		tmp = Float64(Float64(x * y) * y);
	else
		tmp = fma(z, y, t);
	end
	return tmp
end
code[x_, y_, z_, t_] := If[Or[LessEqual[y, -6.5e+93], N[Not[LessEqual[y, 7.2e+110]], $MachinePrecision]], N[(N[(x * y), $MachinePrecision] * y), $MachinePrecision], N[(z * y + t), $MachinePrecision]]
\begin{array}{l}

\\
\begin{array}{l}
\mathbf{if}\;y \leq -6.5 \cdot 10^{+93} \lor \neg \left(y \leq 7.2 \cdot 10^{+110}\right):\\
\;\;\;\;\left(x \cdot y\right) \cdot y\\

\mathbf{else}:\\
\;\;\;\;\mathsf{fma}\left(z, y, t\right)\\


\end{array}
\end{array}
Derivation
  1. Split input into 2 regimes
  2. if y < -6.4999999999999998e93 or 7.1999999999999994e110 < y

    1. Initial program 100.0%

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

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

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

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

        \[\leadsto \color{blue}{\left(y \cdot y\right)} \cdot x \]
      4. lower-*.f6474.5

        \[\leadsto \color{blue}{\left(y \cdot y\right)} \cdot x \]
    5. Applied rewrites74.5%

      \[\leadsto \color{blue}{\left(y \cdot y\right) \cdot x} \]
    6. Step-by-step derivation
      1. Applied rewrites81.9%

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

      if -6.4999999999999998e93 < y < 7.1999999999999994e110

      1. Initial program 100.0%

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

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

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

          \[\leadsto \color{blue}{z \cdot y} + t \]
        3. lower-fma.f6488.2

          \[\leadsto \color{blue}{\mathsf{fma}\left(z, y, t\right)} \]
      5. Applied rewrites88.2%

        \[\leadsto \color{blue}{\mathsf{fma}\left(z, y, t\right)} \]
    7. Recombined 2 regimes into one program.
    8. Final simplification86.1%

      \[\leadsto \begin{array}{l} \mathbf{if}\;y \leq -6.5 \cdot 10^{+93} \lor \neg \left(y \leq 7.2 \cdot 10^{+110}\right):\\ \;\;\;\;\left(x \cdot y\right) \cdot y\\ \mathbf{else}:\\ \;\;\;\;\mathsf{fma}\left(z, y, t\right)\\ \end{array} \]
    9. Add Preprocessing

    Alternative 4: 66.2% accurate, 2.4× speedup?

    \[\begin{array}{l} \\ \mathsf{fma}\left(z, y, t\right) \end{array} \]
    (FPCore (x y z t) :precision binary64 (fma z y t))
    double code(double x, double y, double z, double t) {
    	return fma(z, y, t);
    }
    
    function code(x, y, z, t)
    	return fma(z, y, t)
    end
    
    code[x_, y_, z_, t_] := N[(z * y + t), $MachinePrecision]
    
    \begin{array}{l}
    
    \\
    \mathsf{fma}\left(z, y, t\right)
    \end{array}
    
    Derivation
    1. Initial program 100.0%

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

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

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

        \[\leadsto \color{blue}{z \cdot y} + t \]
      3. lower-fma.f6469.4

        \[\leadsto \color{blue}{\mathsf{fma}\left(z, y, t\right)} \]
    5. Applied rewrites69.4%

      \[\leadsto \color{blue}{\mathsf{fma}\left(z, y, t\right)} \]
    6. Add Preprocessing

    Alternative 5: 30.3% accurate, 2.8× speedup?

    \[\begin{array}{l} \\ z \cdot y \end{array} \]
    (FPCore (x y z t) :precision binary64 (* z y))
    double code(double x, double y, double z, double t) {
    	return z * y;
    }
    
    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 = z * y
    end function
    
    public static double code(double x, double y, double z, double t) {
    	return z * y;
    }
    
    def code(x, y, z, t):
    	return z * y
    
    function code(x, y, z, t)
    	return Float64(z * y)
    end
    
    function tmp = code(x, y, z, t)
    	tmp = z * y;
    end
    
    code[x_, y_, z_, t_] := N[(z * y), $MachinePrecision]
    
    \begin{array}{l}
    
    \\
    z \cdot y
    \end{array}
    
    Derivation
    1. Initial program 100.0%

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

      \[\leadsto \color{blue}{{y}^{2} \cdot \left(x + \frac{z}{y}\right)} \]
    4. Step-by-step derivation
      1. +-commutativeN/A

        \[\leadsto {y}^{2} \cdot \color{blue}{\left(\frac{z}{y} + x\right)} \]
      2. distribute-lft-inN/A

        \[\leadsto \color{blue}{{y}^{2} \cdot \frac{z}{y} + {y}^{2} \cdot x} \]
    5. Applied rewrites62.8%

      \[\leadsto \color{blue}{\mathsf{fma}\left(y, x, z\right) \cdot y} \]
    6. Taylor expanded in x around 0

      \[\leadsto y \cdot \color{blue}{z} \]
    7. Step-by-step derivation
      1. Applied rewrites32.4%

        \[\leadsto z \cdot \color{blue}{y} \]
      2. Add Preprocessing

      Reproduce

      ?
      herbie shell --seed 2024326 
      (FPCore (x y z t)
        :name "Language.Haskell.HsColour.ColourHighlight:unbase from hscolour-1.23"
        :precision binary64
        (+ (* (+ (* x y) z) y) t))