
(FPCore (x) :precision binary64 (/ (* 6.0 (- x 1.0)) (+ (+ x 1.0) (* 4.0 (sqrt x)))))
double code(double x) {
return (6.0 * (x - 1.0)) / ((x + 1.0) + (4.0 * sqrt(x)));
}
real(8) function code(x)
real(8), intent (in) :: x
code = (6.0d0 * (x - 1.0d0)) / ((x + 1.0d0) + (4.0d0 * sqrt(x)))
end function
public static double code(double x) {
return (6.0 * (x - 1.0)) / ((x + 1.0) + (4.0 * Math.sqrt(x)));
}
def code(x): return (6.0 * (x - 1.0)) / ((x + 1.0) + (4.0 * math.sqrt(x)))
function code(x) return Float64(Float64(6.0 * Float64(x - 1.0)) / Float64(Float64(x + 1.0) + Float64(4.0 * sqrt(x)))) end
function tmp = code(x) tmp = (6.0 * (x - 1.0)) / ((x + 1.0) + (4.0 * sqrt(x))); end
code[x_] := N[(N[(6.0 * N[(x - 1.0), $MachinePrecision]), $MachinePrecision] / N[(N[(x + 1.0), $MachinePrecision] + N[(4.0 * N[Sqrt[x], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
\frac{6 \cdot \left(x - 1\right)}{\left(x + 1\right) + 4 \cdot \sqrt{x}}
\end{array}
Sampling outcomes in binary64 precision:
Herbie found 7 alternatives:
| Alternative | Accuracy | Speedup |
|---|
(FPCore (x) :precision binary64 (/ (* 6.0 (- x 1.0)) (+ (+ x 1.0) (* 4.0 (sqrt x)))))
double code(double x) {
return (6.0 * (x - 1.0)) / ((x + 1.0) + (4.0 * sqrt(x)));
}
real(8) function code(x)
real(8), intent (in) :: x
code = (6.0d0 * (x - 1.0d0)) / ((x + 1.0d0) + (4.0d0 * sqrt(x)))
end function
public static double code(double x) {
return (6.0 * (x - 1.0)) / ((x + 1.0) + (4.0 * Math.sqrt(x)));
}
def code(x): return (6.0 * (x - 1.0)) / ((x + 1.0) + (4.0 * math.sqrt(x)))
function code(x) return Float64(Float64(6.0 * Float64(x - 1.0)) / Float64(Float64(x + 1.0) + Float64(4.0 * sqrt(x)))) end
function tmp = code(x) tmp = (6.0 * (x - 1.0)) / ((x + 1.0) + (4.0 * sqrt(x))); end
code[x_] := N[(N[(6.0 * N[(x - 1.0), $MachinePrecision]), $MachinePrecision] / N[(N[(x + 1.0), $MachinePrecision] + N[(4.0 * N[Sqrt[x], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
\frac{6 \cdot \left(x - 1\right)}{\left(x + 1\right) + 4 \cdot \sqrt{x}}
\end{array}
(FPCore (x) :precision binary64 (* (/ (- 1.0 x) (+ -1.0 (fma (sqrt x) -4.0 (- x)))) 6.0))
double code(double x) {
return ((1.0 - x) / (-1.0 + fma(sqrt(x), -4.0, -x))) * 6.0;
}
function code(x) return Float64(Float64(Float64(1.0 - x) / Float64(-1.0 + fma(sqrt(x), -4.0, Float64(-x)))) * 6.0) end
code[x_] := N[(N[(N[(1.0 - x), $MachinePrecision] / N[(-1.0 + N[(N[Sqrt[x], $MachinePrecision] * -4.0 + (-x)), $MachinePrecision]), $MachinePrecision]), $MachinePrecision] * 6.0), $MachinePrecision]
\begin{array}{l}
\\
\frac{1 - x}{-1 + \mathsf{fma}\left(\sqrt{x}, -4, -x\right)} \cdot 6
\end{array}
Initial program 99.8%
lift-/.f64N/A
lift-*.f64N/A
associate-/l*N/A
*-commutativeN/A
lower-*.f64N/A
Applied rewrites99.9%
lift--.f64N/A
sub-negN/A
lift-fma.f64N/A
+-commutativeN/A
associate-+l+N/A
lower-+.f64N/A
*-commutativeN/A
lower-fma.f64N/A
lower-neg.f6499.9
Applied rewrites99.9%
(FPCore (x) :precision binary64 (if (<= (/ (* 6.0 (- x 1.0)) (+ (- x -1.0) (* 4.0 (sqrt x)))) -1.0) (/ (fma x 6.0 -6.0) (fma (sqrt x) 4.0 1.0)) (/ (* 6.0 x) (fma (sqrt x) 4.0 (- x -1.0)))))
double code(double x) {
double tmp;
if (((6.0 * (x - 1.0)) / ((x - -1.0) + (4.0 * sqrt(x)))) <= -1.0) {
tmp = fma(x, 6.0, -6.0) / fma(sqrt(x), 4.0, 1.0);
} else {
tmp = (6.0 * x) / fma(sqrt(x), 4.0, (x - -1.0));
}
return tmp;
}
function code(x) tmp = 0.0 if (Float64(Float64(6.0 * Float64(x - 1.0)) / Float64(Float64(x - -1.0) + Float64(4.0 * sqrt(x)))) <= -1.0) tmp = Float64(fma(x, 6.0, -6.0) / fma(sqrt(x), 4.0, 1.0)); else tmp = Float64(Float64(6.0 * x) / fma(sqrt(x), 4.0, Float64(x - -1.0))); end return tmp end
code[x_] := If[LessEqual[N[(N[(6.0 * N[(x - 1.0), $MachinePrecision]), $MachinePrecision] / N[(N[(x - -1.0), $MachinePrecision] + N[(4.0 * N[Sqrt[x], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision], -1.0], N[(N[(x * 6.0 + -6.0), $MachinePrecision] / N[(N[Sqrt[x], $MachinePrecision] * 4.0 + 1.0), $MachinePrecision]), $MachinePrecision], N[(N[(6.0 * x), $MachinePrecision] / N[(N[Sqrt[x], $MachinePrecision] * 4.0 + N[(x - -1.0), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]]
\begin{array}{l}
\\
\begin{array}{l}
\mathbf{if}\;\frac{6 \cdot \left(x - 1\right)}{\left(x - -1\right) + 4 \cdot \sqrt{x}} \leq -1:\\
\;\;\;\;\frac{\mathsf{fma}\left(x, 6, -6\right)}{\mathsf{fma}\left(\sqrt{x}, 4, 1\right)}\\
\mathbf{else}:\\
\;\;\;\;\frac{6 \cdot x}{\mathsf{fma}\left(\sqrt{x}, 4, x - -1\right)}\\
\end{array}
\end{array}
if (/.f64 (*.f64 #s(literal 6 binary64) (-.f64 x #s(literal 1 binary64))) (+.f64 (+.f64 x #s(literal 1 binary64)) (*.f64 #s(literal 4 binary64) (sqrt.f64 x)))) < -1Initial program 99.9%
Taylor expanded in x around 0
+-commutativeN/A
*-commutativeN/A
lower-fma.f64N/A
lower-sqrt.f6497.7
Applied rewrites97.7%
lift-*.f64N/A
lift--.f64N/A
sub-negN/A
metadata-evalN/A
distribute-rgt-inN/A
metadata-evalN/A
lower-fma.f6497.7
Applied rewrites97.7%
if -1 < (/.f64 (*.f64 #s(literal 6 binary64) (-.f64 x #s(literal 1 binary64))) (+.f64 (+.f64 x #s(literal 1 binary64)) (*.f64 #s(literal 4 binary64) (sqrt.f64 x)))) Initial program 99.7%
lift-*.f64N/A
lift--.f64N/A
sub-negN/A
distribute-rgt-inN/A
metadata-evalN/A
metadata-evalN/A
metadata-evalN/A
metadata-evalN/A
lower-fma.f64N/A
metadata-evalN/A
metadata-eval99.6
lift-+.f64N/A
+-commutativeN/A
lift-*.f64N/A
*-commutativeN/A
lower-fma.f6499.6
lift-+.f64N/A
metadata-evalN/A
metadata-evalN/A
sub-negN/A
lower--.f64N/A
metadata-eval99.6
Applied rewrites99.6%
Taylor expanded in x around inf
lower-*.f6497.6
Applied rewrites97.6%
Final simplification97.6%
(FPCore (x) :precision binary64 (* (/ (- 1.0 x) (- (fma -4.0 (sqrt x) -1.0) x)) 6.0))
double code(double x) {
return ((1.0 - x) / (fma(-4.0, sqrt(x), -1.0) - x)) * 6.0;
}
function code(x) return Float64(Float64(Float64(1.0 - x) / Float64(fma(-4.0, sqrt(x), -1.0) - x)) * 6.0) end
code[x_] := N[(N[(N[(1.0 - x), $MachinePrecision] / N[(N[(-4.0 * N[Sqrt[x], $MachinePrecision] + -1.0), $MachinePrecision] - x), $MachinePrecision]), $MachinePrecision] * 6.0), $MachinePrecision]
\begin{array}{l}
\\
\frac{1 - x}{\mathsf{fma}\left(-4, \sqrt{x}, -1\right) - x} \cdot 6
\end{array}
Initial program 99.8%
lift-/.f64N/A
lift-*.f64N/A
associate-/l*N/A
*-commutativeN/A
lower-*.f64N/A
Applied rewrites99.9%
(FPCore (x) :precision binary64 (/ (fma x 6.0 -6.0) (- (fma 4.0 (sqrt x) x) -1.0)))
double code(double x) {
return fma(x, 6.0, -6.0) / (fma(4.0, sqrt(x), x) - -1.0);
}
function code(x) return Float64(fma(x, 6.0, -6.0) / Float64(fma(4.0, sqrt(x), x) - -1.0)) end
code[x_] := N[(N[(x * 6.0 + -6.0), $MachinePrecision] / N[(N[(4.0 * N[Sqrt[x], $MachinePrecision] + x), $MachinePrecision] - -1.0), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
\frac{\mathsf{fma}\left(x, 6, -6\right)}{\mathsf{fma}\left(4, \sqrt{x}, x\right) - -1}
\end{array}
Initial program 99.8%
lift-*.f64N/A
lift--.f64N/A
sub-negN/A
distribute-rgt-inN/A
metadata-evalN/A
metadata-evalN/A
metadata-evalN/A
metadata-evalN/A
lower-fma.f64N/A
metadata-evalN/A
metadata-eval99.8
lift-+.f64N/A
+-commutativeN/A
lift-*.f64N/A
*-commutativeN/A
lower-fma.f6499.8
lift-+.f64N/A
metadata-evalN/A
metadata-evalN/A
sub-negN/A
lower--.f64N/A
metadata-eval99.8
Applied rewrites99.8%
lift-fma.f64N/A
lift--.f64N/A
associate-+r-N/A
lift-fma.f64N/A
lower--.f6499.8
lift-fma.f64N/A
*-commutativeN/A
lower-fma.f6499.8
Applied rewrites99.8%
(FPCore (x) :precision binary64 (/ (fma x 6.0 -6.0) (fma (sqrt x) 4.0 1.0)))
double code(double x) {
return fma(x, 6.0, -6.0) / fma(sqrt(x), 4.0, 1.0);
}
function code(x) return Float64(fma(x, 6.0, -6.0) / fma(sqrt(x), 4.0, 1.0)) end
code[x_] := N[(N[(x * 6.0 + -6.0), $MachinePrecision] / N[(N[Sqrt[x], $MachinePrecision] * 4.0 + 1.0), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
\frac{\mathsf{fma}\left(x, 6, -6\right)}{\mathsf{fma}\left(\sqrt{x}, 4, 1\right)}
\end{array}
Initial program 99.8%
Taylor expanded in x around 0
+-commutativeN/A
*-commutativeN/A
lower-fma.f64N/A
lower-sqrt.f6457.3
Applied rewrites57.3%
lift-*.f64N/A
lift--.f64N/A
sub-negN/A
metadata-evalN/A
distribute-rgt-inN/A
metadata-evalN/A
lower-fma.f6457.3
Applied rewrites57.3%
(FPCore (x) :precision binary64 (* 6.0 (fma 4.0 (sqrt x) -1.0)))
double code(double x) {
return 6.0 * fma(4.0, sqrt(x), -1.0);
}
function code(x) return Float64(6.0 * fma(4.0, sqrt(x), -1.0)) end
code[x_] := N[(6.0 * N[(4.0 * N[Sqrt[x], $MachinePrecision] + -1.0), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
6 \cdot \mathsf{fma}\left(4, \sqrt{x}, -1\right)
\end{array}
Initial program 99.8%
Taylor expanded in x around 0
lower-/.f64N/A
+-commutativeN/A
*-commutativeN/A
lower-fma.f64N/A
lower-sqrt.f6455.0
Applied rewrites55.0%
Applied rewrites55.0%
Taylor expanded in x around 0
Applied rewrites57.0%
(FPCore (x) :precision binary64 (/ -1.5 (sqrt x)))
double code(double x) {
return -1.5 / sqrt(x);
}
real(8) function code(x)
real(8), intent (in) :: x
code = (-1.5d0) / sqrt(x)
end function
public static double code(double x) {
return -1.5 / Math.sqrt(x);
}
def code(x): return -1.5 / math.sqrt(x)
function code(x) return Float64(-1.5 / sqrt(x)) end
function tmp = code(x) tmp = -1.5 / sqrt(x); end
code[x_] := N[(-1.5 / N[Sqrt[x], $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
\frac{-1.5}{\sqrt{x}}
\end{array}
Initial program 99.8%
Taylor expanded in x around 0
lower-/.f64N/A
+-commutativeN/A
*-commutativeN/A
lower-fma.f64N/A
lower-sqrt.f6455.0
Applied rewrites55.0%
Taylor expanded in x around inf
Applied rewrites4.8%
Applied rewrites4.8%
(FPCore (x) :precision binary64 (/ 6.0 (/ (+ (+ x 1.0) (* 4.0 (sqrt x))) (- x 1.0))))
double code(double x) {
return 6.0 / (((x + 1.0) + (4.0 * sqrt(x))) / (x - 1.0));
}
real(8) function code(x)
real(8), intent (in) :: x
code = 6.0d0 / (((x + 1.0d0) + (4.0d0 * sqrt(x))) / (x - 1.0d0))
end function
public static double code(double x) {
return 6.0 / (((x + 1.0) + (4.0 * Math.sqrt(x))) / (x - 1.0));
}
def code(x): return 6.0 / (((x + 1.0) + (4.0 * math.sqrt(x))) / (x - 1.0))
function code(x) return Float64(6.0 / Float64(Float64(Float64(x + 1.0) + Float64(4.0 * sqrt(x))) / Float64(x - 1.0))) end
function tmp = code(x) tmp = 6.0 / (((x + 1.0) + (4.0 * sqrt(x))) / (x - 1.0)); end
code[x_] := N[(6.0 / N[(N[(N[(x + 1.0), $MachinePrecision] + N[(4.0 * N[Sqrt[x], $MachinePrecision]), $MachinePrecision]), $MachinePrecision] / N[(x - 1.0), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
\frac{6}{\frac{\left(x + 1\right) + 4 \cdot \sqrt{x}}{x - 1}}
\end{array}
herbie shell --seed 2024318
(FPCore (x)
:name "Data.Approximate.Numerics:blog from approximate-0.2.2.1"
:precision binary64
:alt
(! :herbie-platform default (/ 6 (/ (+ (+ x 1) (* 4 (sqrt x))) (- x 1))))
(/ (* 6.0 (- x 1.0)) (+ (+ x 1.0) (* 4.0 (sqrt x)))))