Data.Number.Erf:$cinvnormcdf from erf-2.0.0.0, A

Percentage Accurate: 99.4% → 99.8%
Time: 19.3s
Alternatives: 16
Speedup: 1.1×

Specification

?
\[\begin{array}{l} \\ \left(\left(x \cdot 0.5 - y\right) \cdot \sqrt{z \cdot 2}\right) \cdot e^{\frac{t \cdot t}{2}} \end{array} \]
(FPCore (x y z t)
 :precision binary64
 (* (* (- (* x 0.5) y) (sqrt (* z 2.0))) (exp (/ (* t t) 2.0))))
double code(double x, double y, double z, double t) {
	return (((x * 0.5) - y) * sqrt((z * 2.0))) * exp(((t * t) / 2.0));
}
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 * 0.5d0) - y) * sqrt((z * 2.0d0))) * exp(((t * t) / 2.0d0))
end function
public static double code(double x, double y, double z, double t) {
	return (((x * 0.5) - y) * Math.sqrt((z * 2.0))) * Math.exp(((t * t) / 2.0));
}
def code(x, y, z, t):
	return (((x * 0.5) - y) * math.sqrt((z * 2.0))) * math.exp(((t * t) / 2.0))
function code(x, y, z, t)
	return Float64(Float64(Float64(Float64(x * 0.5) - y) * sqrt(Float64(z * 2.0))) * exp(Float64(Float64(t * t) / 2.0)))
end
function tmp = code(x, y, z, t)
	tmp = (((x * 0.5) - y) * sqrt((z * 2.0))) * exp(((t * t) / 2.0));
end
code[x_, y_, z_, t_] := N[(N[(N[(N[(x * 0.5), $MachinePrecision] - y), $MachinePrecision] * N[Sqrt[N[(z * 2.0), $MachinePrecision]], $MachinePrecision]), $MachinePrecision] * N[Exp[N[(N[(t * t), $MachinePrecision] / 2.0), $MachinePrecision]], $MachinePrecision]), $MachinePrecision]
\begin{array}{l}

\\
\left(\left(x \cdot 0.5 - y\right) \cdot \sqrt{z \cdot 2}\right) \cdot e^{\frac{t \cdot t}{2}}
\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 16 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: 99.4% accurate, 1.0× speedup?

\[\begin{array}{l} \\ \left(\left(x \cdot 0.5 - y\right) \cdot \sqrt{z \cdot 2}\right) \cdot e^{\frac{t \cdot t}{2}} \end{array} \]
(FPCore (x y z t)
 :precision binary64
 (* (* (- (* x 0.5) y) (sqrt (* z 2.0))) (exp (/ (* t t) 2.0))))
double code(double x, double y, double z, double t) {
	return (((x * 0.5) - y) * sqrt((z * 2.0))) * exp(((t * t) / 2.0));
}
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 * 0.5d0) - y) * sqrt((z * 2.0d0))) * exp(((t * t) / 2.0d0))
end function
public static double code(double x, double y, double z, double t) {
	return (((x * 0.5) - y) * Math.sqrt((z * 2.0))) * Math.exp(((t * t) / 2.0));
}
def code(x, y, z, t):
	return (((x * 0.5) - y) * math.sqrt((z * 2.0))) * math.exp(((t * t) / 2.0))
function code(x, y, z, t)
	return Float64(Float64(Float64(Float64(x * 0.5) - y) * sqrt(Float64(z * 2.0))) * exp(Float64(Float64(t * t) / 2.0)))
end
function tmp = code(x, y, z, t)
	tmp = (((x * 0.5) - y) * sqrt((z * 2.0))) * exp(((t * t) / 2.0));
end
code[x_, y_, z_, t_] := N[(N[(N[(N[(x * 0.5), $MachinePrecision] - y), $MachinePrecision] * N[Sqrt[N[(z * 2.0), $MachinePrecision]], $MachinePrecision]), $MachinePrecision] * N[Exp[N[(N[(t * t), $MachinePrecision] / 2.0), $MachinePrecision]], $MachinePrecision]), $MachinePrecision]
\begin{array}{l}

\\
\left(\left(x \cdot 0.5 - y\right) \cdot \sqrt{z \cdot 2}\right) \cdot e^{\frac{t \cdot t}{2}}
\end{array}

Alternative 1: 99.8% accurate, 1.1× speedup?

\[\begin{array}{l} \\ \sqrt{\left(2 \cdot z\right) \cdot e^{t \cdot t}} \cdot \mathsf{fma}\left(0.5, x, -y\right) \end{array} \]
(FPCore (x y z t)
 :precision binary64
 (* (sqrt (* (* 2.0 z) (exp (* t t)))) (fma 0.5 x (- y))))
double code(double x, double y, double z, double t) {
	return sqrt(((2.0 * z) * exp((t * t)))) * fma(0.5, x, -y);
}
function code(x, y, z, t)
	return Float64(sqrt(Float64(Float64(2.0 * z) * exp(Float64(t * t)))) * fma(0.5, x, Float64(-y)))
end
code[x_, y_, z_, t_] := N[(N[Sqrt[N[(N[(2.0 * z), $MachinePrecision] * N[Exp[N[(t * t), $MachinePrecision]], $MachinePrecision]), $MachinePrecision]], $MachinePrecision] * N[(0.5 * x + (-y)), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}

\\
\sqrt{\left(2 \cdot z\right) \cdot e^{t \cdot t}} \cdot \mathsf{fma}\left(0.5, x, -y\right)
\end{array}
Derivation
  1. Initial program 99.5%

    \[\left(\left(x \cdot 0.5 - y\right) \cdot \sqrt{z \cdot 2}\right) \cdot e^{\frac{t \cdot t}{2}} \]
  2. Add Preprocessing
  3. Step-by-step derivation
    1. lift-*.f64N/A

      \[\leadsto \color{blue}{\left(\left(x \cdot \frac{1}{2} - y\right) \cdot \sqrt{z \cdot 2}\right) \cdot e^{\frac{t \cdot t}{2}}} \]
    2. lift-*.f64N/A

      \[\leadsto \color{blue}{\left(\left(x \cdot \frac{1}{2} - y\right) \cdot \sqrt{z \cdot 2}\right)} \cdot e^{\frac{t \cdot t}{2}} \]
    3. associate-*l*N/A

      \[\leadsto \color{blue}{\left(x \cdot \frac{1}{2} - y\right) \cdot \left(\sqrt{z \cdot 2} \cdot e^{\frac{t \cdot t}{2}}\right)} \]
    4. lower-*.f64N/A

      \[\leadsto \color{blue}{\left(x \cdot \frac{1}{2} - y\right) \cdot \left(\sqrt{z \cdot 2} \cdot e^{\frac{t \cdot t}{2}}\right)} \]
    5. lift--.f64N/A

      \[\leadsto \color{blue}{\left(x \cdot \frac{1}{2} - y\right)} \cdot \left(\sqrt{z \cdot 2} \cdot e^{\frac{t \cdot t}{2}}\right) \]
    6. sub-negN/A

      \[\leadsto \color{blue}{\left(x \cdot \frac{1}{2} + \left(\mathsf{neg}\left(y\right)\right)\right)} \cdot \left(\sqrt{z \cdot 2} \cdot e^{\frac{t \cdot t}{2}}\right) \]
    7. lift-*.f64N/A

      \[\leadsto \left(\color{blue}{x \cdot \frac{1}{2}} + \left(\mathsf{neg}\left(y\right)\right)\right) \cdot \left(\sqrt{z \cdot 2} \cdot e^{\frac{t \cdot t}{2}}\right) \]
    8. *-commutativeN/A

      \[\leadsto \left(\color{blue}{\frac{1}{2} \cdot x} + \left(\mathsf{neg}\left(y\right)\right)\right) \cdot \left(\sqrt{z \cdot 2} \cdot e^{\frac{t \cdot t}{2}}\right) \]
    9. lower-fma.f64N/A

      \[\leadsto \color{blue}{\mathsf{fma}\left(\frac{1}{2}, x, \mathsf{neg}\left(y\right)\right)} \cdot \left(\sqrt{z \cdot 2} \cdot e^{\frac{t \cdot t}{2}}\right) \]
    10. lower-neg.f64N/A

      \[\leadsto \mathsf{fma}\left(\frac{1}{2}, x, \color{blue}{\mathsf{neg}\left(y\right)}\right) \cdot \left(\sqrt{z \cdot 2} \cdot e^{\frac{t \cdot t}{2}}\right) \]
    11. lift-sqrt.f64N/A

      \[\leadsto \mathsf{fma}\left(\frac{1}{2}, x, \mathsf{neg}\left(y\right)\right) \cdot \left(\color{blue}{\sqrt{z \cdot 2}} \cdot e^{\frac{t \cdot t}{2}}\right) \]
    12. lift-exp.f64N/A

      \[\leadsto \mathsf{fma}\left(\frac{1}{2}, x, \mathsf{neg}\left(y\right)\right) \cdot \left(\sqrt{z \cdot 2} \cdot \color{blue}{e^{\frac{t \cdot t}{2}}}\right) \]
    13. lift-/.f64N/A

      \[\leadsto \mathsf{fma}\left(\frac{1}{2}, x, \mathsf{neg}\left(y\right)\right) \cdot \left(\sqrt{z \cdot 2} \cdot e^{\color{blue}{\frac{t \cdot t}{2}}}\right) \]
    14. exp-sqrtN/A

      \[\leadsto \mathsf{fma}\left(\frac{1}{2}, x, \mathsf{neg}\left(y\right)\right) \cdot \left(\sqrt{z \cdot 2} \cdot \color{blue}{\sqrt{e^{t \cdot t}}}\right) \]
    15. sqrt-unprodN/A

      \[\leadsto \mathsf{fma}\left(\frac{1}{2}, x, \mathsf{neg}\left(y\right)\right) \cdot \color{blue}{\sqrt{\left(z \cdot 2\right) \cdot e^{t \cdot t}}} \]
    16. lower-sqrt.f64N/A

      \[\leadsto \mathsf{fma}\left(\frac{1}{2}, x, \mathsf{neg}\left(y\right)\right) \cdot \color{blue}{\sqrt{\left(z \cdot 2\right) \cdot e^{t \cdot t}}} \]
    17. *-commutativeN/A

      \[\leadsto \mathsf{fma}\left(\frac{1}{2}, x, \mathsf{neg}\left(y\right)\right) \cdot \sqrt{\color{blue}{e^{t \cdot t} \cdot \left(z \cdot 2\right)}} \]
    18. lower-*.f64N/A

      \[\leadsto \mathsf{fma}\left(\frac{1}{2}, x, \mathsf{neg}\left(y\right)\right) \cdot \sqrt{\color{blue}{e^{t \cdot t} \cdot \left(z \cdot 2\right)}} \]
    19. lower-exp.f6499.9

      \[\leadsto \mathsf{fma}\left(0.5, x, -y\right) \cdot \sqrt{\color{blue}{e^{t \cdot t}} \cdot \left(z \cdot 2\right)} \]
  4. Applied rewrites99.9%

    \[\leadsto \color{blue}{\mathsf{fma}\left(0.5, x, -y\right) \cdot \sqrt{e^{t \cdot t} \cdot \left(z \cdot 2\right)}} \]
  5. Final simplification99.9%

    \[\leadsto \sqrt{\left(2 \cdot z\right) \cdot e^{t \cdot t}} \cdot \mathsf{fma}\left(0.5, x, -y\right) \]
  6. Add Preprocessing

Alternative 2: 97.0% accurate, 0.9× speedup?

\[\begin{array}{l} \\ \begin{array}{l} t_1 := \sqrt{2 \cdot z}\\ t_2 := \mathsf{fma}\left(0.5, x, -y\right)\\ \mathbf{if}\;t \cdot t \leq 2 \cdot 10^{-16}:\\ \;\;\;\;t\_1 \cdot t\_2\\ \mathbf{elif}\;t \cdot t \leq 5 \cdot 10^{+77}:\\ \;\;\;\;\left(x \cdot 0.5\right) \cdot \sqrt{\left(2 \cdot z\right) \cdot e^{t \cdot t}}\\ \mathbf{else}:\\ \;\;\;\;\left(t\_1 \cdot \mathsf{fma}\left(\mathsf{fma}\left(\mathsf{fma}\left(t \cdot t, 0.020833333333333332, 0.125\right), t \cdot t, 0.5\right), t \cdot t, 1\right)\right) \cdot t\_2\\ \end{array} \end{array} \]
(FPCore (x y z t)
 :precision binary64
 (let* ((t_1 (sqrt (* 2.0 z))) (t_2 (fma 0.5 x (- y))))
   (if (<= (* t t) 2e-16)
     (* t_1 t_2)
     (if (<= (* t t) 5e+77)
       (* (* x 0.5) (sqrt (* (* 2.0 z) (exp (* t t)))))
       (*
        (*
         t_1
         (fma
          (fma (fma (* t t) 0.020833333333333332 0.125) (* t t) 0.5)
          (* t t)
          1.0))
        t_2)))))
double code(double x, double y, double z, double t) {
	double t_1 = sqrt((2.0 * z));
	double t_2 = fma(0.5, x, -y);
	double tmp;
	if ((t * t) <= 2e-16) {
		tmp = t_1 * t_2;
	} else if ((t * t) <= 5e+77) {
		tmp = (x * 0.5) * sqrt(((2.0 * z) * exp((t * t))));
	} else {
		tmp = (t_1 * fma(fma(fma((t * t), 0.020833333333333332, 0.125), (t * t), 0.5), (t * t), 1.0)) * t_2;
	}
	return tmp;
}
function code(x, y, z, t)
	t_1 = sqrt(Float64(2.0 * z))
	t_2 = fma(0.5, x, Float64(-y))
	tmp = 0.0
	if (Float64(t * t) <= 2e-16)
		tmp = Float64(t_1 * t_2);
	elseif (Float64(t * t) <= 5e+77)
		tmp = Float64(Float64(x * 0.5) * sqrt(Float64(Float64(2.0 * z) * exp(Float64(t * t)))));
	else
		tmp = Float64(Float64(t_1 * fma(fma(fma(Float64(t * t), 0.020833333333333332, 0.125), Float64(t * t), 0.5), Float64(t * t), 1.0)) * t_2);
	end
	return tmp
end
code[x_, y_, z_, t_] := Block[{t$95$1 = N[Sqrt[N[(2.0 * z), $MachinePrecision]], $MachinePrecision]}, Block[{t$95$2 = N[(0.5 * x + (-y)), $MachinePrecision]}, If[LessEqual[N[(t * t), $MachinePrecision], 2e-16], N[(t$95$1 * t$95$2), $MachinePrecision], If[LessEqual[N[(t * t), $MachinePrecision], 5e+77], N[(N[(x * 0.5), $MachinePrecision] * N[Sqrt[N[(N[(2.0 * z), $MachinePrecision] * N[Exp[N[(t * t), $MachinePrecision]], $MachinePrecision]), $MachinePrecision]], $MachinePrecision]), $MachinePrecision], N[(N[(t$95$1 * N[(N[(N[(N[(t * t), $MachinePrecision] * 0.020833333333333332 + 0.125), $MachinePrecision] * N[(t * t), $MachinePrecision] + 0.5), $MachinePrecision] * N[(t * t), $MachinePrecision] + 1.0), $MachinePrecision]), $MachinePrecision] * t$95$2), $MachinePrecision]]]]]
\begin{array}{l}

\\
\begin{array}{l}
t_1 := \sqrt{2 \cdot z}\\
t_2 := \mathsf{fma}\left(0.5, x, -y\right)\\
\mathbf{if}\;t \cdot t \leq 2 \cdot 10^{-16}:\\
\;\;\;\;t\_1 \cdot t\_2\\

\mathbf{elif}\;t \cdot t \leq 5 \cdot 10^{+77}:\\
\;\;\;\;\left(x \cdot 0.5\right) \cdot \sqrt{\left(2 \cdot z\right) \cdot e^{t \cdot t}}\\

\mathbf{else}:\\
\;\;\;\;\left(t\_1 \cdot \mathsf{fma}\left(\mathsf{fma}\left(\mathsf{fma}\left(t \cdot t, 0.020833333333333332, 0.125\right), t \cdot t, 0.5\right), t \cdot t, 1\right)\right) \cdot t\_2\\


\end{array}
\end{array}
Derivation
  1. Split input into 3 regimes
  2. if (*.f64 t t) < 2e-16

    1. Initial program 99.6%

      \[\left(\left(x \cdot 0.5 - y\right) \cdot \sqrt{z \cdot 2}\right) \cdot e^{\frac{t \cdot t}{2}} \]
    2. Add Preprocessing
    3. Step-by-step derivation
      1. lift-*.f64N/A

        \[\leadsto \color{blue}{\left(\left(x \cdot \frac{1}{2} - y\right) \cdot \sqrt{z \cdot 2}\right) \cdot e^{\frac{t \cdot t}{2}}} \]
      2. lift-*.f64N/A

        \[\leadsto \color{blue}{\left(\left(x \cdot \frac{1}{2} - y\right) \cdot \sqrt{z \cdot 2}\right)} \cdot e^{\frac{t \cdot t}{2}} \]
      3. associate-*l*N/A

        \[\leadsto \color{blue}{\left(x \cdot \frac{1}{2} - y\right) \cdot \left(\sqrt{z \cdot 2} \cdot e^{\frac{t \cdot t}{2}}\right)} \]
      4. lower-*.f64N/A

        \[\leadsto \color{blue}{\left(x \cdot \frac{1}{2} - y\right) \cdot \left(\sqrt{z \cdot 2} \cdot e^{\frac{t \cdot t}{2}}\right)} \]
      5. lift--.f64N/A

        \[\leadsto \color{blue}{\left(x \cdot \frac{1}{2} - y\right)} \cdot \left(\sqrt{z \cdot 2} \cdot e^{\frac{t \cdot t}{2}}\right) \]
      6. sub-negN/A

        \[\leadsto \color{blue}{\left(x \cdot \frac{1}{2} + \left(\mathsf{neg}\left(y\right)\right)\right)} \cdot \left(\sqrt{z \cdot 2} \cdot e^{\frac{t \cdot t}{2}}\right) \]
      7. lift-*.f64N/A

        \[\leadsto \left(\color{blue}{x \cdot \frac{1}{2}} + \left(\mathsf{neg}\left(y\right)\right)\right) \cdot \left(\sqrt{z \cdot 2} \cdot e^{\frac{t \cdot t}{2}}\right) \]
      8. *-commutativeN/A

        \[\leadsto \left(\color{blue}{\frac{1}{2} \cdot x} + \left(\mathsf{neg}\left(y\right)\right)\right) \cdot \left(\sqrt{z \cdot 2} \cdot e^{\frac{t \cdot t}{2}}\right) \]
      9. lower-fma.f64N/A

        \[\leadsto \color{blue}{\mathsf{fma}\left(\frac{1}{2}, x, \mathsf{neg}\left(y\right)\right)} \cdot \left(\sqrt{z \cdot 2} \cdot e^{\frac{t \cdot t}{2}}\right) \]
      10. lower-neg.f64N/A

        \[\leadsto \mathsf{fma}\left(\frac{1}{2}, x, \color{blue}{\mathsf{neg}\left(y\right)}\right) \cdot \left(\sqrt{z \cdot 2} \cdot e^{\frac{t \cdot t}{2}}\right) \]
      11. lift-sqrt.f64N/A

        \[\leadsto \mathsf{fma}\left(\frac{1}{2}, x, \mathsf{neg}\left(y\right)\right) \cdot \left(\color{blue}{\sqrt{z \cdot 2}} \cdot e^{\frac{t \cdot t}{2}}\right) \]
      12. lift-exp.f64N/A

        \[\leadsto \mathsf{fma}\left(\frac{1}{2}, x, \mathsf{neg}\left(y\right)\right) \cdot \left(\sqrt{z \cdot 2} \cdot \color{blue}{e^{\frac{t \cdot t}{2}}}\right) \]
      13. lift-/.f64N/A

        \[\leadsto \mathsf{fma}\left(\frac{1}{2}, x, \mathsf{neg}\left(y\right)\right) \cdot \left(\sqrt{z \cdot 2} \cdot e^{\color{blue}{\frac{t \cdot t}{2}}}\right) \]
      14. exp-sqrtN/A

        \[\leadsto \mathsf{fma}\left(\frac{1}{2}, x, \mathsf{neg}\left(y\right)\right) \cdot \left(\sqrt{z \cdot 2} \cdot \color{blue}{\sqrt{e^{t \cdot t}}}\right) \]
      15. sqrt-unprodN/A

        \[\leadsto \mathsf{fma}\left(\frac{1}{2}, x, \mathsf{neg}\left(y\right)\right) \cdot \color{blue}{\sqrt{\left(z \cdot 2\right) \cdot e^{t \cdot t}}} \]
      16. lower-sqrt.f64N/A

        \[\leadsto \mathsf{fma}\left(\frac{1}{2}, x, \mathsf{neg}\left(y\right)\right) \cdot \color{blue}{\sqrt{\left(z \cdot 2\right) \cdot e^{t \cdot t}}} \]
      17. *-commutativeN/A

        \[\leadsto \mathsf{fma}\left(\frac{1}{2}, x, \mathsf{neg}\left(y\right)\right) \cdot \sqrt{\color{blue}{e^{t \cdot t} \cdot \left(z \cdot 2\right)}} \]
      18. lower-*.f64N/A

        \[\leadsto \mathsf{fma}\left(\frac{1}{2}, x, \mathsf{neg}\left(y\right)\right) \cdot \sqrt{\color{blue}{e^{t \cdot t} \cdot \left(z \cdot 2\right)}} \]
      19. lower-exp.f6499.6

        \[\leadsto \mathsf{fma}\left(0.5, x, -y\right) \cdot \sqrt{\color{blue}{e^{t \cdot t}} \cdot \left(z \cdot 2\right)} \]
    4. Applied rewrites99.6%

      \[\leadsto \color{blue}{\mathsf{fma}\left(0.5, x, -y\right) \cdot \sqrt{e^{t \cdot t} \cdot \left(z \cdot 2\right)}} \]
    5. Taylor expanded in t around 0

      \[\leadsto \mathsf{fma}\left(\frac{1}{2}, x, \mathsf{neg}\left(y\right)\right) \cdot \sqrt{\color{blue}{2 \cdot z}} \]
    6. Step-by-step derivation
      1. *-commutativeN/A

        \[\leadsto \mathsf{fma}\left(\frac{1}{2}, x, \mathsf{neg}\left(y\right)\right) \cdot \sqrt{\color{blue}{z \cdot 2}} \]
      2. lower-*.f6499.6

        \[\leadsto \mathsf{fma}\left(0.5, x, -y\right) \cdot \sqrt{\color{blue}{z \cdot 2}} \]
    7. Applied rewrites99.6%

      \[\leadsto \mathsf{fma}\left(0.5, x, -y\right) \cdot \sqrt{\color{blue}{z \cdot 2}} \]

    if 2e-16 < (*.f64 t t) < 5.00000000000000004e77

    1. Initial program 99.2%

      \[\left(\left(x \cdot 0.5 - y\right) \cdot \sqrt{z \cdot 2}\right) \cdot e^{\frac{t \cdot t}{2}} \]
    2. Add Preprocessing
    3. Step-by-step derivation
      1. lift-*.f64N/A

        \[\leadsto \color{blue}{\left(\left(x \cdot \frac{1}{2} - y\right) \cdot \sqrt{z \cdot 2}\right) \cdot e^{\frac{t \cdot t}{2}}} \]
      2. lift-*.f64N/A

        \[\leadsto \color{blue}{\left(\left(x \cdot \frac{1}{2} - y\right) \cdot \sqrt{z \cdot 2}\right)} \cdot e^{\frac{t \cdot t}{2}} \]
      3. associate-*l*N/A

        \[\leadsto \color{blue}{\left(x \cdot \frac{1}{2} - y\right) \cdot \left(\sqrt{z \cdot 2} \cdot e^{\frac{t \cdot t}{2}}\right)} \]
      4. lower-*.f64N/A

        \[\leadsto \color{blue}{\left(x \cdot \frac{1}{2} - y\right) \cdot \left(\sqrt{z \cdot 2} \cdot e^{\frac{t \cdot t}{2}}\right)} \]
      5. lift--.f64N/A

        \[\leadsto \color{blue}{\left(x \cdot \frac{1}{2} - y\right)} \cdot \left(\sqrt{z \cdot 2} \cdot e^{\frac{t \cdot t}{2}}\right) \]
      6. sub-negN/A

        \[\leadsto \color{blue}{\left(x \cdot \frac{1}{2} + \left(\mathsf{neg}\left(y\right)\right)\right)} \cdot \left(\sqrt{z \cdot 2} \cdot e^{\frac{t \cdot t}{2}}\right) \]
      7. lift-*.f64N/A

        \[\leadsto \left(\color{blue}{x \cdot \frac{1}{2}} + \left(\mathsf{neg}\left(y\right)\right)\right) \cdot \left(\sqrt{z \cdot 2} \cdot e^{\frac{t \cdot t}{2}}\right) \]
      8. *-commutativeN/A

        \[\leadsto \left(\color{blue}{\frac{1}{2} \cdot x} + \left(\mathsf{neg}\left(y\right)\right)\right) \cdot \left(\sqrt{z \cdot 2} \cdot e^{\frac{t \cdot t}{2}}\right) \]
      9. lower-fma.f64N/A

        \[\leadsto \color{blue}{\mathsf{fma}\left(\frac{1}{2}, x, \mathsf{neg}\left(y\right)\right)} \cdot \left(\sqrt{z \cdot 2} \cdot e^{\frac{t \cdot t}{2}}\right) \]
      10. lower-neg.f64N/A

        \[\leadsto \mathsf{fma}\left(\frac{1}{2}, x, \color{blue}{\mathsf{neg}\left(y\right)}\right) \cdot \left(\sqrt{z \cdot 2} \cdot e^{\frac{t \cdot t}{2}}\right) \]
      11. lift-sqrt.f64N/A

        \[\leadsto \mathsf{fma}\left(\frac{1}{2}, x, \mathsf{neg}\left(y\right)\right) \cdot \left(\color{blue}{\sqrt{z \cdot 2}} \cdot e^{\frac{t \cdot t}{2}}\right) \]
      12. lift-exp.f64N/A

        \[\leadsto \mathsf{fma}\left(\frac{1}{2}, x, \mathsf{neg}\left(y\right)\right) \cdot \left(\sqrt{z \cdot 2} \cdot \color{blue}{e^{\frac{t \cdot t}{2}}}\right) \]
      13. lift-/.f64N/A

        \[\leadsto \mathsf{fma}\left(\frac{1}{2}, x, \mathsf{neg}\left(y\right)\right) \cdot \left(\sqrt{z \cdot 2} \cdot e^{\color{blue}{\frac{t \cdot t}{2}}}\right) \]
      14. exp-sqrtN/A

        \[\leadsto \mathsf{fma}\left(\frac{1}{2}, x, \mathsf{neg}\left(y\right)\right) \cdot \left(\sqrt{z \cdot 2} \cdot \color{blue}{\sqrt{e^{t \cdot t}}}\right) \]
      15. sqrt-unprodN/A

        \[\leadsto \mathsf{fma}\left(\frac{1}{2}, x, \mathsf{neg}\left(y\right)\right) \cdot \color{blue}{\sqrt{\left(z \cdot 2\right) \cdot e^{t \cdot t}}} \]
      16. lower-sqrt.f64N/A

        \[\leadsto \mathsf{fma}\left(\frac{1}{2}, x, \mathsf{neg}\left(y\right)\right) \cdot \color{blue}{\sqrt{\left(z \cdot 2\right) \cdot e^{t \cdot t}}} \]
      17. *-commutativeN/A

        \[\leadsto \mathsf{fma}\left(\frac{1}{2}, x, \mathsf{neg}\left(y\right)\right) \cdot \sqrt{\color{blue}{e^{t \cdot t} \cdot \left(z \cdot 2\right)}} \]
      18. lower-*.f64N/A

        \[\leadsto \mathsf{fma}\left(\frac{1}{2}, x, \mathsf{neg}\left(y\right)\right) \cdot \sqrt{\color{blue}{e^{t \cdot t} \cdot \left(z \cdot 2\right)}} \]
      19. lower-exp.f6499.6

        \[\leadsto \mathsf{fma}\left(0.5, x, -y\right) \cdot \sqrt{\color{blue}{e^{t \cdot t}} \cdot \left(z \cdot 2\right)} \]
    4. Applied rewrites99.6%

      \[\leadsto \color{blue}{\mathsf{fma}\left(0.5, x, -y\right) \cdot \sqrt{e^{t \cdot t} \cdot \left(z \cdot 2\right)}} \]
    5. Taylor expanded in x around inf

      \[\leadsto \color{blue}{\left(\frac{1}{2} \cdot x\right)} \cdot \sqrt{e^{t \cdot t} \cdot \left(z \cdot 2\right)} \]
    6. Step-by-step derivation
      1. *-commutativeN/A

        \[\leadsto \color{blue}{\left(x \cdot \frac{1}{2}\right)} \cdot \sqrt{e^{t \cdot t} \cdot \left(z \cdot 2\right)} \]
      2. lower-*.f6469.7

        \[\leadsto \color{blue}{\left(x \cdot 0.5\right)} \cdot \sqrt{e^{t \cdot t} \cdot \left(z \cdot 2\right)} \]
    7. Applied rewrites69.7%

      \[\leadsto \color{blue}{\left(x \cdot 0.5\right)} \cdot \sqrt{e^{t \cdot t} \cdot \left(z \cdot 2\right)} \]

    if 5.00000000000000004e77 < (*.f64 t t)

    1. Initial program 99.1%

      \[\left(\left(x \cdot 0.5 - y\right) \cdot \sqrt{z \cdot 2}\right) \cdot e^{\frac{t \cdot t}{2}} \]
    2. Add Preprocessing
    3. Taylor expanded in t around 0

      \[\leadsto \left(\left(x \cdot \frac{1}{2} - y\right) \cdot \sqrt{z \cdot 2}\right) \cdot \color{blue}{\left(1 + {t}^{2} \cdot \left(\frac{1}{2} + {t}^{2} \cdot \left(\frac{1}{8} + \frac{1}{48} \cdot {t}^{2}\right)\right)\right)} \]
    4. Step-by-step derivation
      1. +-commutativeN/A

        \[\leadsto \left(\left(x \cdot \frac{1}{2} - y\right) \cdot \sqrt{z \cdot 2}\right) \cdot \color{blue}{\left({t}^{2} \cdot \left(\frac{1}{2} + {t}^{2} \cdot \left(\frac{1}{8} + \frac{1}{48} \cdot {t}^{2}\right)\right) + 1\right)} \]
      2. *-commutativeN/A

        \[\leadsto \left(\left(x \cdot \frac{1}{2} - y\right) \cdot \sqrt{z \cdot 2}\right) \cdot \left(\color{blue}{\left(\frac{1}{2} + {t}^{2} \cdot \left(\frac{1}{8} + \frac{1}{48} \cdot {t}^{2}\right)\right) \cdot {t}^{2}} + 1\right) \]
      3. lower-fma.f64N/A

        \[\leadsto \left(\left(x \cdot \frac{1}{2} - y\right) \cdot \sqrt{z \cdot 2}\right) \cdot \color{blue}{\mathsf{fma}\left(\frac{1}{2} + {t}^{2} \cdot \left(\frac{1}{8} + \frac{1}{48} \cdot {t}^{2}\right), {t}^{2}, 1\right)} \]
      4. +-commutativeN/A

        \[\leadsto \left(\left(x \cdot \frac{1}{2} - y\right) \cdot \sqrt{z \cdot 2}\right) \cdot \mathsf{fma}\left(\color{blue}{{t}^{2} \cdot \left(\frac{1}{8} + \frac{1}{48} \cdot {t}^{2}\right) + \frac{1}{2}}, {t}^{2}, 1\right) \]
      5. *-commutativeN/A

        \[\leadsto \left(\left(x \cdot \frac{1}{2} - y\right) \cdot \sqrt{z \cdot 2}\right) \cdot \mathsf{fma}\left(\color{blue}{\left(\frac{1}{8} + \frac{1}{48} \cdot {t}^{2}\right) \cdot {t}^{2}} + \frac{1}{2}, {t}^{2}, 1\right) \]
      6. lower-fma.f64N/A

        \[\leadsto \left(\left(x \cdot \frac{1}{2} - y\right) \cdot \sqrt{z \cdot 2}\right) \cdot \mathsf{fma}\left(\color{blue}{\mathsf{fma}\left(\frac{1}{8} + \frac{1}{48} \cdot {t}^{2}, {t}^{2}, \frac{1}{2}\right)}, {t}^{2}, 1\right) \]
      7. +-commutativeN/A

        \[\leadsto \left(\left(x \cdot \frac{1}{2} - y\right) \cdot \sqrt{z \cdot 2}\right) \cdot \mathsf{fma}\left(\mathsf{fma}\left(\color{blue}{\frac{1}{48} \cdot {t}^{2} + \frac{1}{8}}, {t}^{2}, \frac{1}{2}\right), {t}^{2}, 1\right) \]
      8. lower-fma.f64N/A

        \[\leadsto \left(\left(x \cdot \frac{1}{2} - y\right) \cdot \sqrt{z \cdot 2}\right) \cdot \mathsf{fma}\left(\mathsf{fma}\left(\color{blue}{\mathsf{fma}\left(\frac{1}{48}, {t}^{2}, \frac{1}{8}\right)}, {t}^{2}, \frac{1}{2}\right), {t}^{2}, 1\right) \]
      9. unpow2N/A

        \[\leadsto \left(\left(x \cdot \frac{1}{2} - y\right) \cdot \sqrt{z \cdot 2}\right) \cdot \mathsf{fma}\left(\mathsf{fma}\left(\mathsf{fma}\left(\frac{1}{48}, \color{blue}{t \cdot t}, \frac{1}{8}\right), {t}^{2}, \frac{1}{2}\right), {t}^{2}, 1\right) \]
      10. lower-*.f64N/A

        \[\leadsto \left(\left(x \cdot \frac{1}{2} - y\right) \cdot \sqrt{z \cdot 2}\right) \cdot \mathsf{fma}\left(\mathsf{fma}\left(\mathsf{fma}\left(\frac{1}{48}, \color{blue}{t \cdot t}, \frac{1}{8}\right), {t}^{2}, \frac{1}{2}\right), {t}^{2}, 1\right) \]
      11. unpow2N/A

        \[\leadsto \left(\left(x \cdot \frac{1}{2} - y\right) \cdot \sqrt{z \cdot 2}\right) \cdot \mathsf{fma}\left(\mathsf{fma}\left(\mathsf{fma}\left(\frac{1}{48}, t \cdot t, \frac{1}{8}\right), \color{blue}{t \cdot t}, \frac{1}{2}\right), {t}^{2}, 1\right) \]
      12. lower-*.f64N/A

        \[\leadsto \left(\left(x \cdot \frac{1}{2} - y\right) \cdot \sqrt{z \cdot 2}\right) \cdot \mathsf{fma}\left(\mathsf{fma}\left(\mathsf{fma}\left(\frac{1}{48}, t \cdot t, \frac{1}{8}\right), \color{blue}{t \cdot t}, \frac{1}{2}\right), {t}^{2}, 1\right) \]
      13. unpow2N/A

        \[\leadsto \left(\left(x \cdot \frac{1}{2} - y\right) \cdot \sqrt{z \cdot 2}\right) \cdot \mathsf{fma}\left(\mathsf{fma}\left(\mathsf{fma}\left(\frac{1}{48}, t \cdot t, \frac{1}{8}\right), t \cdot t, \frac{1}{2}\right), \color{blue}{t \cdot t}, 1\right) \]
      14. lower-*.f6497.4

        \[\leadsto \left(\left(x \cdot 0.5 - y\right) \cdot \sqrt{z \cdot 2}\right) \cdot \mathsf{fma}\left(\mathsf{fma}\left(\mathsf{fma}\left(0.020833333333333332, t \cdot t, 0.125\right), t \cdot t, 0.5\right), \color{blue}{t \cdot t}, 1\right) \]
    5. Applied rewrites97.4%

      \[\leadsto \left(\left(x \cdot 0.5 - y\right) \cdot \sqrt{z \cdot 2}\right) \cdot \color{blue}{\mathsf{fma}\left(\mathsf{fma}\left(\mathsf{fma}\left(0.020833333333333332, t \cdot t, 0.125\right), t \cdot t, 0.5\right), t \cdot t, 1\right)} \]
    6. Step-by-step derivation
      1. lift-*.f64N/A

        \[\leadsto \color{blue}{\left(\left(x \cdot \frac{1}{2} - y\right) \cdot \sqrt{z \cdot 2}\right) \cdot \mathsf{fma}\left(\mathsf{fma}\left(\mathsf{fma}\left(\frac{1}{48}, t \cdot t, \frac{1}{8}\right), t \cdot t, \frac{1}{2}\right), t \cdot t, 1\right)} \]
      2. lift-*.f64N/A

        \[\leadsto \color{blue}{\left(\left(x \cdot \frac{1}{2} - y\right) \cdot \sqrt{z \cdot 2}\right)} \cdot \mathsf{fma}\left(\mathsf{fma}\left(\mathsf{fma}\left(\frac{1}{48}, t \cdot t, \frac{1}{8}\right), t \cdot t, \frac{1}{2}\right), t \cdot t, 1\right) \]
      3. associate-*l*N/A

        \[\leadsto \color{blue}{\left(x \cdot \frac{1}{2} - y\right) \cdot \left(\sqrt{z \cdot 2} \cdot \mathsf{fma}\left(\mathsf{fma}\left(\mathsf{fma}\left(\frac{1}{48}, t \cdot t, \frac{1}{8}\right), t \cdot t, \frac{1}{2}\right), t \cdot t, 1\right)\right)} \]
      4. lower-*.f64N/A

        \[\leadsto \color{blue}{\left(x \cdot \frac{1}{2} - y\right) \cdot \left(\sqrt{z \cdot 2} \cdot \mathsf{fma}\left(\mathsf{fma}\left(\mathsf{fma}\left(\frac{1}{48}, t \cdot t, \frac{1}{8}\right), t \cdot t, \frac{1}{2}\right), t \cdot t, 1\right)\right)} \]
      5. lift--.f64N/A

        \[\leadsto \color{blue}{\left(x \cdot \frac{1}{2} - y\right)} \cdot \left(\sqrt{z \cdot 2} \cdot \mathsf{fma}\left(\mathsf{fma}\left(\mathsf{fma}\left(\frac{1}{48}, t \cdot t, \frac{1}{8}\right), t \cdot t, \frac{1}{2}\right), t \cdot t, 1\right)\right) \]
      6. sub-negN/A

        \[\leadsto \color{blue}{\left(x \cdot \frac{1}{2} + \left(\mathsf{neg}\left(y\right)\right)\right)} \cdot \left(\sqrt{z \cdot 2} \cdot \mathsf{fma}\left(\mathsf{fma}\left(\mathsf{fma}\left(\frac{1}{48}, t \cdot t, \frac{1}{8}\right), t \cdot t, \frac{1}{2}\right), t \cdot t, 1\right)\right) \]
      7. lift-neg.f64N/A

        \[\leadsto \left(x \cdot \frac{1}{2} + \color{blue}{\left(\mathsf{neg}\left(y\right)\right)}\right) \cdot \left(\sqrt{z \cdot 2} \cdot \mathsf{fma}\left(\mathsf{fma}\left(\mathsf{fma}\left(\frac{1}{48}, t \cdot t, \frac{1}{8}\right), t \cdot t, \frac{1}{2}\right), t \cdot t, 1\right)\right) \]
      8. lift-*.f64N/A

        \[\leadsto \left(\color{blue}{x \cdot \frac{1}{2}} + \left(\mathsf{neg}\left(y\right)\right)\right) \cdot \left(\sqrt{z \cdot 2} \cdot \mathsf{fma}\left(\mathsf{fma}\left(\mathsf{fma}\left(\frac{1}{48}, t \cdot t, \frac{1}{8}\right), t \cdot t, \frac{1}{2}\right), t \cdot t, 1\right)\right) \]
      9. *-commutativeN/A

        \[\leadsto \left(\color{blue}{\frac{1}{2} \cdot x} + \left(\mathsf{neg}\left(y\right)\right)\right) \cdot \left(\sqrt{z \cdot 2} \cdot \mathsf{fma}\left(\mathsf{fma}\left(\mathsf{fma}\left(\frac{1}{48}, t \cdot t, \frac{1}{8}\right), t \cdot t, \frac{1}{2}\right), t \cdot t, 1\right)\right) \]
      10. lift-fma.f64N/A

        \[\leadsto \color{blue}{\mathsf{fma}\left(\frac{1}{2}, x, \mathsf{neg}\left(y\right)\right)} \cdot \left(\sqrt{z \cdot 2} \cdot \mathsf{fma}\left(\mathsf{fma}\left(\mathsf{fma}\left(\frac{1}{48}, t \cdot t, \frac{1}{8}\right), t \cdot t, \frac{1}{2}\right), t \cdot t, 1\right)\right) \]
      11. *-commutativeN/A

        \[\leadsto \mathsf{fma}\left(\frac{1}{2}, x, \mathsf{neg}\left(y\right)\right) \cdot \color{blue}{\left(\mathsf{fma}\left(\mathsf{fma}\left(\mathsf{fma}\left(\frac{1}{48}, t \cdot t, \frac{1}{8}\right), t \cdot t, \frac{1}{2}\right), t \cdot t, 1\right) \cdot \sqrt{z \cdot 2}\right)} \]
      12. lower-*.f6498.7

        \[\leadsto \mathsf{fma}\left(0.5, x, -y\right) \cdot \color{blue}{\left(\mathsf{fma}\left(\mathsf{fma}\left(\mathsf{fma}\left(0.020833333333333332, t \cdot t, 0.125\right), t \cdot t, 0.5\right), t \cdot t, 1\right) \cdot \sqrt{z \cdot 2}\right)} \]
    7. Applied rewrites98.7%

      \[\leadsto \color{blue}{\mathsf{fma}\left(0.5, x, -y\right) \cdot \left(\mathsf{fma}\left(\mathsf{fma}\left(\mathsf{fma}\left(t \cdot t, 0.020833333333333332, 0.125\right), t \cdot t, 0.5\right), t \cdot t, 1\right) \cdot \sqrt{2 \cdot z}\right)} \]
  3. Recombined 3 regimes into one program.
  4. Final simplification97.0%

    \[\leadsto \begin{array}{l} \mathbf{if}\;t \cdot t \leq 2 \cdot 10^{-16}:\\ \;\;\;\;\sqrt{2 \cdot z} \cdot \mathsf{fma}\left(0.5, x, -y\right)\\ \mathbf{elif}\;t \cdot t \leq 5 \cdot 10^{+77}:\\ \;\;\;\;\left(x \cdot 0.5\right) \cdot \sqrt{\left(2 \cdot z\right) \cdot e^{t \cdot t}}\\ \mathbf{else}:\\ \;\;\;\;\left(\sqrt{2 \cdot z} \cdot \mathsf{fma}\left(\mathsf{fma}\left(\mathsf{fma}\left(t \cdot t, 0.020833333333333332, 0.125\right), t \cdot t, 0.5\right), t \cdot t, 1\right)\right) \cdot \mathsf{fma}\left(0.5, x, -y\right)\\ \end{array} \]
  5. Add Preprocessing

Developer Target 1: 99.3% accurate, 0.6× speedup?

\[\begin{array}{l} \\ \left(\left(x \cdot 0.5 - y\right) \cdot \sqrt{z \cdot 2}\right) \cdot {\left(e^{1}\right)}^{\left(\frac{t \cdot t}{2}\right)} \end{array} \]
(FPCore (x y z t)
 :precision binary64
 (* (* (- (* x 0.5) y) (sqrt (* z 2.0))) (pow (exp 1.0) (/ (* t t) 2.0))))
double code(double x, double y, double z, double t) {
	return (((x * 0.5) - y) * sqrt((z * 2.0))) * pow(exp(1.0), ((t * t) / 2.0));
}
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 * 0.5d0) - y) * sqrt((z * 2.0d0))) * (exp(1.0d0) ** ((t * t) / 2.0d0))
end function
public static double code(double x, double y, double z, double t) {
	return (((x * 0.5) - y) * Math.sqrt((z * 2.0))) * Math.pow(Math.exp(1.0), ((t * t) / 2.0));
}
def code(x, y, z, t):
	return (((x * 0.5) - y) * math.sqrt((z * 2.0))) * math.pow(math.exp(1.0), ((t * t) / 2.0))
function code(x, y, z, t)
	return Float64(Float64(Float64(Float64(x * 0.5) - y) * sqrt(Float64(z * 2.0))) * (exp(1.0) ^ Float64(Float64(t * t) / 2.0)))
end
function tmp = code(x, y, z, t)
	tmp = (((x * 0.5) - y) * sqrt((z * 2.0))) * (exp(1.0) ^ ((t * t) / 2.0));
end
code[x_, y_, z_, t_] := N[(N[(N[(N[(x * 0.5), $MachinePrecision] - y), $MachinePrecision] * N[Sqrt[N[(z * 2.0), $MachinePrecision]], $MachinePrecision]), $MachinePrecision] * N[Power[N[Exp[1.0], $MachinePrecision], N[(N[(t * t), $MachinePrecision] / 2.0), $MachinePrecision]], $MachinePrecision]), $MachinePrecision]
\begin{array}{l}

\\
\left(\left(x \cdot 0.5 - y\right) \cdot \sqrt{z \cdot 2}\right) \cdot {\left(e^{1}\right)}^{\left(\frac{t \cdot t}{2}\right)}
\end{array}

Reproduce

?
herbie shell --seed 2024230 
(FPCore (x y z t)
  :name "Data.Number.Erf:$cinvnormcdf from erf-2.0.0.0, A"
  :precision binary64

  :alt
  (! :herbie-platform default (* (* (- (* x 1/2) y) (sqrt (* z 2))) (pow (exp 1) (/ (* t t) 2))))

  (* (* (- (* x 0.5) y) (sqrt (* z 2.0))) (exp (/ (* t t) 2.0))))