
(FPCore (x y z) :precision binary64 (+ x (/ y (- (* 1.1283791670955126 (exp z)) (* x y)))))
double code(double x, double y, double z) {
return x + (y / ((1.1283791670955126 * exp(z)) - (x * y)));
}
real(8) function code(x, y, z)
real(8), intent (in) :: x
real(8), intent (in) :: y
real(8), intent (in) :: z
code = x + (y / ((1.1283791670955126d0 * exp(z)) - (x * y)))
end function
public static double code(double x, double y, double z) {
return x + (y / ((1.1283791670955126 * Math.exp(z)) - (x * y)));
}
def code(x, y, z): return x + (y / ((1.1283791670955126 * math.exp(z)) - (x * y)))
function code(x, y, z) return Float64(x + Float64(y / Float64(Float64(1.1283791670955126 * exp(z)) - Float64(x * y)))) end
function tmp = code(x, y, z) tmp = x + (y / ((1.1283791670955126 * exp(z)) - (x * y))); end
code[x_, y_, z_] := N[(x + N[(y / N[(N[(1.1283791670955126 * N[Exp[z], $MachinePrecision]), $MachinePrecision] - N[(x * y), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
x + \frac{y}{1.1283791670955126 \cdot e^{z} - x \cdot y}
\end{array}
Sampling outcomes in binary64 precision:
Herbie found 14 alternatives:
| Alternative | Accuracy | Speedup |
|---|
(FPCore (x y z) :precision binary64 (+ x (/ y (- (* 1.1283791670955126 (exp z)) (* x y)))))
double code(double x, double y, double z) {
return x + (y / ((1.1283791670955126 * exp(z)) - (x * y)));
}
real(8) function code(x, y, z)
real(8), intent (in) :: x
real(8), intent (in) :: y
real(8), intent (in) :: z
code = x + (y / ((1.1283791670955126d0 * exp(z)) - (x * y)))
end function
public static double code(double x, double y, double z) {
return x + (y / ((1.1283791670955126 * Math.exp(z)) - (x * y)));
}
def code(x, y, z): return x + (y / ((1.1283791670955126 * math.exp(z)) - (x * y)))
function code(x, y, z) return Float64(x + Float64(y / Float64(Float64(1.1283791670955126 * exp(z)) - Float64(x * y)))) end
function tmp = code(x, y, z) tmp = x + (y / ((1.1283791670955126 * exp(z)) - (x * y))); end
code[x_, y_, z_] := N[(x + N[(y / N[(N[(1.1283791670955126 * N[Exp[z], $MachinePrecision]), $MachinePrecision] - N[(x * y), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
x + \frac{y}{1.1283791670955126 \cdot e^{z} - x \cdot y}
\end{array}
(FPCore (x y z)
:precision binary64
(let* ((t_0 (* z (fma z 0.18806319451591877 0.5641895835477563))))
(if (<= (exp z) 0.0)
(+ x (/ -1.0 x))
(if (<= (exp z) 1.00000000000002)
(+
x
(/
y
(-
(fma
z
(/
(fma t_0 t_0 -1.2732395447351628)
(fma
z
(fma z 0.18806319451591877 0.5641895835477563)
-1.1283791670955126))
1.1283791670955126)
(* x y))))
(fma (exp (- z)) (* y 0.8862269254527579) x)))))
double code(double x, double y, double z) {
double t_0 = z * fma(z, 0.18806319451591877, 0.5641895835477563);
double tmp;
if (exp(z) <= 0.0) {
tmp = x + (-1.0 / x);
} else if (exp(z) <= 1.00000000000002) {
tmp = x + (y / (fma(z, (fma(t_0, t_0, -1.2732395447351628) / fma(z, fma(z, 0.18806319451591877, 0.5641895835477563), -1.1283791670955126)), 1.1283791670955126) - (x * y)));
} else {
tmp = fma(exp(-z), (y * 0.8862269254527579), x);
}
return tmp;
}
function code(x, y, z) t_0 = Float64(z * fma(z, 0.18806319451591877, 0.5641895835477563)) tmp = 0.0 if (exp(z) <= 0.0) tmp = Float64(x + Float64(-1.0 / x)); elseif (exp(z) <= 1.00000000000002) tmp = Float64(x + Float64(y / Float64(fma(z, Float64(fma(t_0, t_0, -1.2732395447351628) / fma(z, fma(z, 0.18806319451591877, 0.5641895835477563), -1.1283791670955126)), 1.1283791670955126) - Float64(x * y)))); else tmp = fma(exp(Float64(-z)), Float64(y * 0.8862269254527579), x); end return tmp end
code[x_, y_, z_] := Block[{t$95$0 = N[(z * N[(z * 0.18806319451591877 + 0.5641895835477563), $MachinePrecision]), $MachinePrecision]}, If[LessEqual[N[Exp[z], $MachinePrecision], 0.0], N[(x + N[(-1.0 / x), $MachinePrecision]), $MachinePrecision], If[LessEqual[N[Exp[z], $MachinePrecision], 1.00000000000002], N[(x + N[(y / N[(N[(z * N[(N[(t$95$0 * t$95$0 + -1.2732395447351628), $MachinePrecision] / N[(z * N[(z * 0.18806319451591877 + 0.5641895835477563), $MachinePrecision] + -1.1283791670955126), $MachinePrecision]), $MachinePrecision] + 1.1283791670955126), $MachinePrecision] - N[(x * y), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision], N[(N[Exp[(-z)], $MachinePrecision] * N[(y * 0.8862269254527579), $MachinePrecision] + x), $MachinePrecision]]]]
\begin{array}{l}
\\
\begin{array}{l}
t_0 := z \cdot \mathsf{fma}\left(z, 0.18806319451591877, 0.5641895835477563\right)\\
\mathbf{if}\;e^{z} \leq 0:\\
\;\;\;\;x + \frac{-1}{x}\\
\mathbf{elif}\;e^{z} \leq 1.00000000000002:\\
\;\;\;\;x + \frac{y}{\mathsf{fma}\left(z, \frac{\mathsf{fma}\left(t\_0, t\_0, -1.2732395447351628\right)}{\mathsf{fma}\left(z, \mathsf{fma}\left(z, 0.18806319451591877, 0.5641895835477563\right), -1.1283791670955126\right)}, 1.1283791670955126\right) - x \cdot y}\\
\mathbf{else}:\\
\;\;\;\;\mathsf{fma}\left(e^{-z}, y \cdot 0.8862269254527579, x\right)\\
\end{array}
\end{array}
if (exp.f64 z) < 0.0Initial program 92.3%
Taylor expanded in y around inf
lower-/.f64100.0
Applied rewrites100.0%
if 0.0 < (exp.f64 z) < 1.00000000000002Initial program 99.8%
Taylor expanded in z around 0
+-commutativeN/A
lower-fma.f64N/A
+-commutativeN/A
lower-fma.f64N/A
+-commutativeN/A
*-commutativeN/A
lower-fma.f6499.8
Applied rewrites99.8%
Applied rewrites99.8%
if 1.00000000000002 < (exp.f64 z) Initial program 95.5%
Taylor expanded in y around 0
+-commutativeN/A
*-lft-identityN/A
associate-*l/N/A
associate-*l*N/A
*-commutativeN/A
associate-*l*N/A
lower-fma.f64N/A
rec-expN/A
neg-mul-1N/A
lower-exp.f64N/A
neg-mul-1N/A
lower-neg.f64N/A
lower-*.f64100.0
Applied rewrites100.0%
Final simplification99.9%
(FPCore (x y z)
:precision binary64
(let* ((t_0 (+ x (/ -1.0 x)))
(t_1 (+ x (/ y (- (* 1.1283791670955126 (exp z)) (* x y))))))
(if (<= t_1 -10.0)
t_0
(if (<= t_1 -1e-157)
(+ x (* y (fma y (* x 0.7853981633974483) 0.8862269254527579)))
(if (<= t_1 4e-7) (+ x (* (* y (* x y)) 0.7853981633974483)) t_0)))))
double code(double x, double y, double z) {
double t_0 = x + (-1.0 / x);
double t_1 = x + (y / ((1.1283791670955126 * exp(z)) - (x * y)));
double tmp;
if (t_1 <= -10.0) {
tmp = t_0;
} else if (t_1 <= -1e-157) {
tmp = x + (y * fma(y, (x * 0.7853981633974483), 0.8862269254527579));
} else if (t_1 <= 4e-7) {
tmp = x + ((y * (x * y)) * 0.7853981633974483);
} else {
tmp = t_0;
}
return tmp;
}
function code(x, y, z) t_0 = Float64(x + Float64(-1.0 / x)) t_1 = Float64(x + Float64(y / Float64(Float64(1.1283791670955126 * exp(z)) - Float64(x * y)))) tmp = 0.0 if (t_1 <= -10.0) tmp = t_0; elseif (t_1 <= -1e-157) tmp = Float64(x + Float64(y * fma(y, Float64(x * 0.7853981633974483), 0.8862269254527579))); elseif (t_1 <= 4e-7) tmp = Float64(x + Float64(Float64(y * Float64(x * y)) * 0.7853981633974483)); else tmp = t_0; end return tmp end
code[x_, y_, z_] := Block[{t$95$0 = N[(x + N[(-1.0 / x), $MachinePrecision]), $MachinePrecision]}, Block[{t$95$1 = N[(x + N[(y / N[(N[(1.1283791670955126 * N[Exp[z], $MachinePrecision]), $MachinePrecision] - N[(x * y), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]}, If[LessEqual[t$95$1, -10.0], t$95$0, If[LessEqual[t$95$1, -1e-157], N[(x + N[(y * N[(y * N[(x * 0.7853981633974483), $MachinePrecision] + 0.8862269254527579), $MachinePrecision]), $MachinePrecision]), $MachinePrecision], If[LessEqual[t$95$1, 4e-7], N[(x + N[(N[(y * N[(x * y), $MachinePrecision]), $MachinePrecision] * 0.7853981633974483), $MachinePrecision]), $MachinePrecision], t$95$0]]]]]
\begin{array}{l}
\\
\begin{array}{l}
t_0 := x + \frac{-1}{x}\\
t_1 := x + \frac{y}{1.1283791670955126 \cdot e^{z} - x \cdot y}\\
\mathbf{if}\;t\_1 \leq -10:\\
\;\;\;\;t\_0\\
\mathbf{elif}\;t\_1 \leq -1 \cdot 10^{-157}:\\
\;\;\;\;x + y \cdot \mathsf{fma}\left(y, x \cdot 0.7853981633974483, 0.8862269254527579\right)\\
\mathbf{elif}\;t\_1 \leq 4 \cdot 10^{-7}:\\
\;\;\;\;x + \left(y \cdot \left(x \cdot y\right)\right) \cdot 0.7853981633974483\\
\mathbf{else}:\\
\;\;\;\;t\_0\\
\end{array}
\end{array}
if (+.f64 x (/.f64 y (-.f64 (*.f64 #s(literal 5641895835477563/5000000000000000 binary64) (exp.f64 z)) (*.f64 x y)))) < -10 or 3.9999999999999998e-7 < (+.f64 x (/.f64 y (-.f64 (*.f64 #s(literal 5641895835477563/5000000000000000 binary64) (exp.f64 z)) (*.f64 x y)))) Initial program 94.0%
Taylor expanded in y around inf
lower-/.f6491.1
Applied rewrites91.1%
if -10 < (+.f64 x (/.f64 y (-.f64 (*.f64 #s(literal 5641895835477563/5000000000000000 binary64) (exp.f64 z)) (*.f64 x y)))) < -9.99999999999999943e-158Initial program 99.9%
Taylor expanded in z around 0
associate-/l*N/A
associate-*r*N/A
lower-fma.f64N/A
Applied rewrites67.1%
Taylor expanded in y around 0
Applied rewrites66.3%
Taylor expanded in z around 0
Applied rewrites75.8%
if -9.99999999999999943e-158 < (+.f64 x (/.f64 y (-.f64 (*.f64 #s(literal 5641895835477563/5000000000000000 binary64) (exp.f64 z)) (*.f64 x y)))) < 3.9999999999999998e-7Initial program 99.9%
Taylor expanded in z around 0
associate-/l*N/A
associate-*r*N/A
lower-fma.f64N/A
Applied rewrites47.9%
Taylor expanded in y around 0
Applied rewrites47.8%
Taylor expanded in x around -inf
Applied rewrites46.7%
Taylor expanded in z around 0
Applied rewrites51.1%
Final simplification83.1%
(FPCore (x y z) :precision binary64 (+ x (/ 1.0 (- (* (/ 1.1283791670955126 y) (exp z)) x))))
double code(double x, double y, double z) {
return x + (1.0 / (((1.1283791670955126 / y) * exp(z)) - x));
}
real(8) function code(x, y, z)
real(8), intent (in) :: x
real(8), intent (in) :: y
real(8), intent (in) :: z
code = x + (1.0d0 / (((1.1283791670955126d0 / y) * exp(z)) - x))
end function
public static double code(double x, double y, double z) {
return x + (1.0 / (((1.1283791670955126 / y) * Math.exp(z)) - x));
}
def code(x, y, z): return x + (1.0 / (((1.1283791670955126 / y) * math.exp(z)) - x))
function code(x, y, z) return Float64(x + Float64(1.0 / Float64(Float64(Float64(1.1283791670955126 / y) * exp(z)) - x))) end
function tmp = code(x, y, z) tmp = x + (1.0 / (((1.1283791670955126 / y) * exp(z)) - x)); end
code[x_, y_, z_] := N[(x + N[(1.0 / N[(N[(N[(1.1283791670955126 / y), $MachinePrecision] * N[Exp[z], $MachinePrecision]), $MachinePrecision] - x), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
x + \frac{1}{\frac{1.1283791670955126}{y} \cdot e^{z} - x}
\end{array}
herbie shell --seed 2024228
(FPCore (x y z)
:name "Numeric.SpecFunctions:invErfc from math-functions-0.1.5.2, A"
:precision binary64
:alt
(! :herbie-platform default (+ x (/ 1 (- (* (/ 5641895835477563/5000000000000000 y) (exp z)) x))))
(+ x (/ y (- (* 1.1283791670955126 (exp z)) (* x y)))))