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

Percentage Accurate: 99.9% → 99.9%
Time: 6.6s
Alternatives: 6
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 6 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?

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

\\
\mathsf{fma}\left(\mathsf{fma}\left(x, y, 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

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

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

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

Alternative 2: 71.0% accurate, 0.3× speedup?

\[\begin{array}{l} \\ \begin{array}{l} t_1 := t + y \cdot \left(z + x \cdot y\right)\\ t_2 := x \cdot \left(y \cdot y\right)\\ \mathbf{if}\;t\_1 \leq -1 \cdot 10^{+263}:\\ \;\;\;\;t\_2\\ \mathbf{elif}\;t\_1 \leq \infty:\\ \;\;\;\;\mathsf{fma}\left(y, z, t\right)\\ \mathbf{else}:\\ \;\;\;\;t\_2\\ \end{array} \end{array} \]
(FPCore (x y z t)
 :precision binary64
 (let* ((t_1 (+ t (* y (+ z (* x y))))) (t_2 (* x (* y y))))
   (if (<= t_1 -1e+263) t_2 (if (<= t_1 INFINITY) (fma y z t) t_2))))
double code(double x, double y, double z, double t) {
	double t_1 = t + (y * (z + (x * y)));
	double t_2 = x * (y * y);
	double tmp;
	if (t_1 <= -1e+263) {
		tmp = t_2;
	} else if (t_1 <= ((double) INFINITY)) {
		tmp = fma(y, z, t);
	} else {
		tmp = t_2;
	}
	return tmp;
}
function code(x, y, z, t)
	t_1 = Float64(t + Float64(y * Float64(z + Float64(x * y))))
	t_2 = Float64(x * Float64(y * y))
	tmp = 0.0
	if (t_1 <= -1e+263)
		tmp = t_2;
	elseif (t_1 <= Inf)
		tmp = fma(y, z, t);
	else
		tmp = t_2;
	end
	return tmp
end
code[x_, y_, z_, t_] := Block[{t$95$1 = N[(t + N[(y * N[(z + N[(x * y), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]}, Block[{t$95$2 = N[(x * N[(y * y), $MachinePrecision]), $MachinePrecision]}, If[LessEqual[t$95$1, -1e+263], t$95$2, If[LessEqual[t$95$1, Infinity], N[(y * z + t), $MachinePrecision], t$95$2]]]]
\begin{array}{l}

\\
\begin{array}{l}
t_1 := t + y \cdot \left(z + x \cdot y\right)\\
t_2 := x \cdot \left(y \cdot y\right)\\
\mathbf{if}\;t\_1 \leq -1 \cdot 10^{+263}:\\
\;\;\;\;t\_2\\

\mathbf{elif}\;t\_1 \leq \infty:\\
\;\;\;\;\mathsf{fma}\left(y, z, t\right)\\

\mathbf{else}:\\
\;\;\;\;t\_2\\


\end{array}
\end{array}
Derivation
  1. Split input into 2 regimes
  2. if (+.f64 (*.f64 (+.f64 (*.f64 x y) z) y) t) < -1.00000000000000002e263 or +inf.0 < (+.f64 (*.f64 (+.f64 (*.f64 x y) z) y) t)

    1. Initial program 99.9%

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

      \[\leadsto \color{blue}{x \cdot {y}^{2}} \]
    4. Step-by-step derivation
      1. unpow2N/A

        \[\leadsto x \cdot \color{blue}{\left(y \cdot y\right)} \]
      2. associate-*r*N/A

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

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

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

        \[\leadsto y \cdot \color{blue}{\left(y \cdot x\right)} \]
      6. lower-*.f6480.6

        \[\leadsto y \cdot \color{blue}{\left(y \cdot x\right)} \]
    5. Applied rewrites80.6%

      \[\leadsto \color{blue}{y \cdot \left(y \cdot x\right)} \]
    6. Step-by-step derivation
      1. associate-*r*N/A

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

        \[\leadsto \color{blue}{\left(y \cdot y\right) \cdot x} \]
      3. lower-*.f6480.8

        \[\leadsto \color{blue}{\left(y \cdot y\right)} \cdot x \]
    7. Applied rewrites80.8%

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

    if -1.00000000000000002e263 < (+.f64 (*.f64 (+.f64 (*.f64 x y) z) y) t) < +inf.0

    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. lower-fma.f6476.5

        \[\leadsto \color{blue}{\mathsf{fma}\left(y, z, t\right)} \]
    5. Applied rewrites76.5%

      \[\leadsto \color{blue}{\mathsf{fma}\left(y, z, t\right)} \]
  3. Recombined 2 regimes into one program.
  4. Final simplification77.4%

    \[\leadsto \begin{array}{l} \mathbf{if}\;t + y \cdot \left(z + x \cdot y\right) \leq -1 \cdot 10^{+263}:\\ \;\;\;\;x \cdot \left(y \cdot y\right)\\ \mathbf{elif}\;t + y \cdot \left(z + x \cdot y\right) \leq \infty:\\ \;\;\;\;\mathsf{fma}\left(y, z, t\right)\\ \mathbf{else}:\\ \;\;\;\;x \cdot \left(y \cdot y\right)\\ \end{array} \]
  5. Add Preprocessing

Alternative 3: 91.4% accurate, 0.3× speedup?

\[\begin{array}{l} \\ \begin{array}{l} t_1 := y \cdot \left(z + x \cdot y\right)\\ t_2 := y \cdot \mathsf{fma}\left(y, x, z\right)\\ \mathbf{if}\;t\_1 \leq -1 \cdot 10^{+108}:\\ \;\;\;\;t\_2\\ \mathbf{elif}\;t\_1 \leq 6 \cdot 10^{+118}:\\ \;\;\;\;\mathsf{fma}\left(y, z, t\right)\\ \mathbf{else}:\\ \;\;\;\;t\_2\\ \end{array} \end{array} \]
(FPCore (x y z t)
 :precision binary64
 (let* ((t_1 (* y (+ z (* x y)))) (t_2 (* y (fma y x z))))
   (if (<= t_1 -1e+108) t_2 (if (<= t_1 6e+118) (fma y z t) t_2))))
double code(double x, double y, double z, double t) {
	double t_1 = y * (z + (x * y));
	double t_2 = y * fma(y, x, z);
	double tmp;
	if (t_1 <= -1e+108) {
		tmp = t_2;
	} else if (t_1 <= 6e+118) {
		tmp = fma(y, z, t);
	} else {
		tmp = t_2;
	}
	return tmp;
}
function code(x, y, z, t)
	t_1 = Float64(y * Float64(z + Float64(x * y)))
	t_2 = Float64(y * fma(y, x, z))
	tmp = 0.0
	if (t_1 <= -1e+108)
		tmp = t_2;
	elseif (t_1 <= 6e+118)
		tmp = fma(y, z, t);
	else
		tmp = t_2;
	end
	return tmp
end
code[x_, y_, z_, t_] := Block[{t$95$1 = N[(y * N[(z + N[(x * y), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]}, Block[{t$95$2 = N[(y * N[(y * x + z), $MachinePrecision]), $MachinePrecision]}, If[LessEqual[t$95$1, -1e+108], t$95$2, If[LessEqual[t$95$1, 6e+118], N[(y * z + t), $MachinePrecision], t$95$2]]]]
\begin{array}{l}

\\
\begin{array}{l}
t_1 := y \cdot \left(z + x \cdot y\right)\\
t_2 := y \cdot \mathsf{fma}\left(y, x, z\right)\\
\mathbf{if}\;t\_1 \leq -1 \cdot 10^{+108}:\\
\;\;\;\;t\_2\\

\mathbf{elif}\;t\_1 \leq 6 \cdot 10^{+118}:\\
\;\;\;\;\mathsf{fma}\left(y, z, t\right)\\

\mathbf{else}:\\
\;\;\;\;t\_2\\


\end{array}
\end{array}
Derivation
  1. Split input into 2 regimes
  2. if (*.f64 (+.f64 (*.f64 x y) z) y) < -1e108 or 6e118 < (*.f64 (+.f64 (*.f64 x y) z) y)

    1. Initial program 99.9%

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

      \[\leadsto \color{blue}{{y}^{2} \cdot \left(x + \frac{z}{y}\right)} \]
    4. Applied rewrites95.6%

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

    if -1e108 < (*.f64 (+.f64 (*.f64 x y) z) y) < 6e118

    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. lower-fma.f6492.1

        \[\leadsto \color{blue}{\mathsf{fma}\left(y, z, t\right)} \]
    5. Applied rewrites92.1%

      \[\leadsto \color{blue}{\mathsf{fma}\left(y, z, t\right)} \]
  3. Recombined 2 regimes into one program.
  4. Final simplification93.8%

    \[\leadsto \begin{array}{l} \mathbf{if}\;y \cdot \left(z + x \cdot y\right) \leq -1 \cdot 10^{+108}:\\ \;\;\;\;y \cdot \mathsf{fma}\left(y, x, z\right)\\ \mathbf{elif}\;y \cdot \left(z + x \cdot y\right) \leq 6 \cdot 10^{+118}:\\ \;\;\;\;\mathsf{fma}\left(y, z, t\right)\\ \mathbf{else}:\\ \;\;\;\;y \cdot \mathsf{fma}\left(y, x, z\right)\\ \end{array} \]
  5. Add Preprocessing

Alternative 4: 78.6% accurate, 0.7× speedup?

\[\begin{array}{l} \\ \begin{array}{l} t_1 := y \cdot \left(x \cdot y\right)\\ \mathbf{if}\;y \leq -1.8 \cdot 10^{+138}:\\ \;\;\;\;t\_1\\ \mathbf{elif}\;y \leq 14:\\ \;\;\;\;\mathsf{fma}\left(y, z, t\right)\\ \mathbf{else}:\\ \;\;\;\;t\_1\\ \end{array} \end{array} \]
(FPCore (x y z t)
 :precision binary64
 (let* ((t_1 (* y (* x y))))
   (if (<= y -1.8e+138) t_1 (if (<= y 14.0) (fma y z t) t_1))))
double code(double x, double y, double z, double t) {
	double t_1 = y * (x * y);
	double tmp;
	if (y <= -1.8e+138) {
		tmp = t_1;
	} else if (y <= 14.0) {
		tmp = fma(y, z, t);
	} else {
		tmp = t_1;
	}
	return tmp;
}
function code(x, y, z, t)
	t_1 = Float64(y * Float64(x * y))
	tmp = 0.0
	if (y <= -1.8e+138)
		tmp = t_1;
	elseif (y <= 14.0)
		tmp = fma(y, z, t);
	else
		tmp = t_1;
	end
	return tmp
end
code[x_, y_, z_, t_] := Block[{t$95$1 = N[(y * N[(x * y), $MachinePrecision]), $MachinePrecision]}, If[LessEqual[y, -1.8e+138], t$95$1, If[LessEqual[y, 14.0], N[(y * z + t), $MachinePrecision], t$95$1]]]
\begin{array}{l}

\\
\begin{array}{l}
t_1 := y \cdot \left(x \cdot y\right)\\
\mathbf{if}\;y \leq -1.8 \cdot 10^{+138}:\\
\;\;\;\;t\_1\\

\mathbf{elif}\;y \leq 14:\\
\;\;\;\;\mathsf{fma}\left(y, z, t\right)\\

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


\end{array}
\end{array}
Derivation
  1. Split input into 2 regimes
  2. if y < -1.8000000000000001e138 or 14 < y

    1. Initial program 99.9%

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

      \[\leadsto \color{blue}{x \cdot {y}^{2}} \]
    4. Step-by-step derivation
      1. unpow2N/A

        \[\leadsto x \cdot \color{blue}{\left(y \cdot y\right)} \]
      2. associate-*r*N/A

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

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

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

        \[\leadsto y \cdot \color{blue}{\left(y \cdot x\right)} \]
      6. lower-*.f6475.7

        \[\leadsto y \cdot \color{blue}{\left(y \cdot x\right)} \]
    5. Applied rewrites75.7%

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

    if -1.8000000000000001e138 < y < 14

    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. lower-fma.f6488.1

        \[\leadsto \color{blue}{\mathsf{fma}\left(y, z, t\right)} \]
    5. Applied rewrites88.1%

      \[\leadsto \color{blue}{\mathsf{fma}\left(y, z, t\right)} \]
  3. Recombined 2 regimes into one program.
  4. Final simplification83.1%

    \[\leadsto \begin{array}{l} \mathbf{if}\;y \leq -1.8 \cdot 10^{+138}:\\ \;\;\;\;y \cdot \left(x \cdot y\right)\\ \mathbf{elif}\;y \leq 14:\\ \;\;\;\;\mathsf{fma}\left(y, z, t\right)\\ \mathbf{else}:\\ \;\;\;\;y \cdot \left(x \cdot y\right)\\ \end{array} \]
  5. Add Preprocessing

Alternative 5: 66.3% accurate, 2.4× speedup?

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

\\
\mathsf{fma}\left(y, z, 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. lower-fma.f6468.2

      \[\leadsto \color{blue}{\mathsf{fma}\left(y, z, t\right)} \]
  5. Applied rewrites68.2%

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

Alternative 6: 29.3% accurate, 2.8× speedup?

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

\\
y \cdot z
\end{array}
Derivation
  1. Initial program 100.0%

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

    \[\leadsto \color{blue}{y \cdot z} \]
  4. Step-by-step derivation
    1. lower-*.f6430.8

      \[\leadsto \color{blue}{y \cdot z} \]
  5. Applied rewrites30.8%

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

Reproduce

?
herbie shell --seed 2024214 
(FPCore (x y z t)
  :name "Language.Haskell.HsColour.ColourHighlight:unbase from hscolour-1.23"
  :precision binary64
  (+ (* (+ (* x y) z) y) t))