
(FPCore (x) :precision binary64 (- 1.0 (sqrt (* 0.5 (+ 1.0 (/ 1.0 (hypot 1.0 x)))))))
double code(double x) {
return 1.0 - sqrt((0.5 * (1.0 + (1.0 / hypot(1.0, x)))));
}
public static double code(double x) {
return 1.0 - Math.sqrt((0.5 * (1.0 + (1.0 / Math.hypot(1.0, x)))));
}
def code(x): return 1.0 - math.sqrt((0.5 * (1.0 + (1.0 / math.hypot(1.0, x)))))
function code(x) return Float64(1.0 - sqrt(Float64(0.5 * Float64(1.0 + Float64(1.0 / hypot(1.0, x)))))) end
function tmp = code(x) tmp = 1.0 - sqrt((0.5 * (1.0 + (1.0 / hypot(1.0, x))))); end
code[x_] := N[(1.0 - N[Sqrt[N[(0.5 * N[(1.0 + N[(1.0 / N[Sqrt[1.0 ^ 2 + x ^ 2], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]], $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
1 - \sqrt{0.5 \cdot \left(1 + \frac{1}{\mathsf{hypot}\left(1, x\right)}\right)}
\end{array}
Sampling outcomes in binary64 precision:
Herbie found 8 alternatives:
| Alternative | Accuracy | Speedup |
|---|
(FPCore (x) :precision binary64 (- 1.0 (sqrt (* 0.5 (+ 1.0 (/ 1.0 (hypot 1.0 x)))))))
double code(double x) {
return 1.0 - sqrt((0.5 * (1.0 + (1.0 / hypot(1.0, x)))));
}
public static double code(double x) {
return 1.0 - Math.sqrt((0.5 * (1.0 + (1.0 / Math.hypot(1.0, x)))));
}
def code(x): return 1.0 - math.sqrt((0.5 * (1.0 + (1.0 / math.hypot(1.0, x)))))
function code(x) return Float64(1.0 - sqrt(Float64(0.5 * Float64(1.0 + Float64(1.0 / hypot(1.0, x)))))) end
function tmp = code(x) tmp = 1.0 - sqrt((0.5 * (1.0 + (1.0 / hypot(1.0, x))))); end
code[x_] := N[(1.0 - N[Sqrt[N[(0.5 * N[(1.0 + N[(1.0 / N[Sqrt[1.0 ^ 2 + x ^ 2], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]], $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
1 - \sqrt{0.5 \cdot \left(1 + \frac{1}{\mathsf{hypot}\left(1, x\right)}\right)}
\end{array}
(FPCore (x) :precision binary64 (let* ((t_0 (/ 0.5 (hypot 1.0 x)))) (/ (- 0.5 t_0) (+ 1.0 (sqrt (+ 0.5 t_0))))))
double code(double x) {
double t_0 = 0.5 / hypot(1.0, x);
return (0.5 - t_0) / (1.0 + sqrt((0.5 + t_0)));
}
public static double code(double x) {
double t_0 = 0.5 / Math.hypot(1.0, x);
return (0.5 - t_0) / (1.0 + Math.sqrt((0.5 + t_0)));
}
def code(x): t_0 = 0.5 / math.hypot(1.0, x) return (0.5 - t_0) / (1.0 + math.sqrt((0.5 + t_0)))
function code(x) t_0 = Float64(0.5 / hypot(1.0, x)) return Float64(Float64(0.5 - t_0) / Float64(1.0 + sqrt(Float64(0.5 + t_0)))) end
function tmp = code(x) t_0 = 0.5 / hypot(1.0, x); tmp = (0.5 - t_0) / (1.0 + sqrt((0.5 + t_0))); end
code[x_] := Block[{t$95$0 = N[(0.5 / N[Sqrt[1.0 ^ 2 + x ^ 2], $MachinePrecision]), $MachinePrecision]}, N[(N[(0.5 - t$95$0), $MachinePrecision] / N[(1.0 + N[Sqrt[N[(0.5 + t$95$0), $MachinePrecision]], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]]
\begin{array}{l}
\\
\begin{array}{l}
t_0 := \frac{0.5}{\mathsf{hypot}\left(1, x\right)}\\
\frac{0.5 - t\_0}{1 + \sqrt{0.5 + t\_0}}
\end{array}
\end{array}
Initial program 99.2%
distribute-lft-in99.2%
metadata-eval99.2%
associate-*r/99.2%
metadata-eval99.2%
Simplified99.2%
flip--99.2%
metadata-eval99.2%
add-sqr-sqrt100.0%
associate--r+100.0%
metadata-eval100.0%
Applied egg-rr100.0%
Final simplification100.0%
(FPCore (x) :precision binary64 (if (<= (hypot 1.0 x) 2.0) (/ (- 0.5 (/ 0.5 (hypot 1.0 x))) 2.0) (/ (- 0.5 (/ 0.5 x)) (+ 1.0 (sqrt 0.5)))))
double code(double x) {
double tmp;
if (hypot(1.0, x) <= 2.0) {
tmp = (0.5 - (0.5 / hypot(1.0, x))) / 2.0;
} else {
tmp = (0.5 - (0.5 / x)) / (1.0 + sqrt(0.5));
}
return tmp;
}
public static double code(double x) {
double tmp;
if (Math.hypot(1.0, x) <= 2.0) {
tmp = (0.5 - (0.5 / Math.hypot(1.0, x))) / 2.0;
} else {
tmp = (0.5 - (0.5 / x)) / (1.0 + Math.sqrt(0.5));
}
return tmp;
}
def code(x): tmp = 0 if math.hypot(1.0, x) <= 2.0: tmp = (0.5 - (0.5 / math.hypot(1.0, x))) / 2.0 else: tmp = (0.5 - (0.5 / x)) / (1.0 + math.sqrt(0.5)) return tmp
function code(x) tmp = 0.0 if (hypot(1.0, x) <= 2.0) tmp = Float64(Float64(0.5 - Float64(0.5 / hypot(1.0, x))) / 2.0); else tmp = Float64(Float64(0.5 - Float64(0.5 / x)) / Float64(1.0 + sqrt(0.5))); end return tmp end
function tmp_2 = code(x) tmp = 0.0; if (hypot(1.0, x) <= 2.0) tmp = (0.5 - (0.5 / hypot(1.0, x))) / 2.0; else tmp = (0.5 - (0.5 / x)) / (1.0 + sqrt(0.5)); end tmp_2 = tmp; end
code[x_] := If[LessEqual[N[Sqrt[1.0 ^ 2 + x ^ 2], $MachinePrecision], 2.0], N[(N[(0.5 - N[(0.5 / N[Sqrt[1.0 ^ 2 + x ^ 2], $MachinePrecision]), $MachinePrecision]), $MachinePrecision] / 2.0), $MachinePrecision], N[(N[(0.5 - N[(0.5 / x), $MachinePrecision]), $MachinePrecision] / N[(1.0 + N[Sqrt[0.5], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]]
\begin{array}{l}
\\
\begin{array}{l}
\mathbf{if}\;\mathsf{hypot}\left(1, x\right) \leq 2:\\
\;\;\;\;\frac{0.5 - \frac{0.5}{\mathsf{hypot}\left(1, x\right)}}{2}\\
\mathbf{else}:\\
\;\;\;\;\frac{0.5 - \frac{0.5}{x}}{1 + \sqrt{0.5}}\\
\end{array}
\end{array}
if (hypot.f64 1 x) < 2Initial program 99.9%
distribute-lft-in99.9%
metadata-eval99.9%
associate-*r/99.9%
metadata-eval99.9%
Simplified99.9%
flip--99.9%
metadata-eval99.9%
add-sqr-sqrt100.0%
associate--r+100.0%
metadata-eval100.0%
Applied egg-rr100.0%
Taylor expanded in x around 0 99.5%
if 2 < (hypot.f64 1 x) Initial program 98.5%
distribute-lft-in98.5%
metadata-eval98.5%
associate-*r/98.5%
metadata-eval98.5%
Simplified98.5%
flip--98.5%
metadata-eval98.5%
add-sqr-sqrt100.0%
associate--r+100.0%
metadata-eval100.0%
Applied egg-rr100.0%
Taylor expanded in x around inf 99.1%
associate-*r/99.1%
metadata-eval99.1%
Simplified99.1%
Taylor expanded in x around inf 98.6%
Final simplification99.1%
(FPCore (x) :precision binary64 (if (<= (hypot 1.0 x) 2.0) (/ (- 0.5 (/ 0.5 (hypot 1.0 x))) 2.0) (/ 0.5 (+ 1.0 (sqrt 0.5)))))
double code(double x) {
double tmp;
if (hypot(1.0, x) <= 2.0) {
tmp = (0.5 - (0.5 / hypot(1.0, x))) / 2.0;
} else {
tmp = 0.5 / (1.0 + sqrt(0.5));
}
return tmp;
}
public static double code(double x) {
double tmp;
if (Math.hypot(1.0, x) <= 2.0) {
tmp = (0.5 - (0.5 / Math.hypot(1.0, x))) / 2.0;
} else {
tmp = 0.5 / (1.0 + Math.sqrt(0.5));
}
return tmp;
}
def code(x): tmp = 0 if math.hypot(1.0, x) <= 2.0: tmp = (0.5 - (0.5 / math.hypot(1.0, x))) / 2.0 else: tmp = 0.5 / (1.0 + math.sqrt(0.5)) return tmp
function code(x) tmp = 0.0 if (hypot(1.0, x) <= 2.0) tmp = Float64(Float64(0.5 - Float64(0.5 / hypot(1.0, x))) / 2.0); else tmp = Float64(0.5 / Float64(1.0 + sqrt(0.5))); end return tmp end
function tmp_2 = code(x) tmp = 0.0; if (hypot(1.0, x) <= 2.0) tmp = (0.5 - (0.5 / hypot(1.0, x))) / 2.0; else tmp = 0.5 / (1.0 + sqrt(0.5)); end tmp_2 = tmp; end
code[x_] := If[LessEqual[N[Sqrt[1.0 ^ 2 + x ^ 2], $MachinePrecision], 2.0], N[(N[(0.5 - N[(0.5 / N[Sqrt[1.0 ^ 2 + x ^ 2], $MachinePrecision]), $MachinePrecision]), $MachinePrecision] / 2.0), $MachinePrecision], N[(0.5 / N[(1.0 + N[Sqrt[0.5], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]]
\begin{array}{l}
\\
\begin{array}{l}
\mathbf{if}\;\mathsf{hypot}\left(1, x\right) \leq 2:\\
\;\;\;\;\frac{0.5 - \frac{0.5}{\mathsf{hypot}\left(1, x\right)}}{2}\\
\mathbf{else}:\\
\;\;\;\;\frac{0.5}{1 + \sqrt{0.5}}\\
\end{array}
\end{array}
if (hypot.f64 1 x) < 2Initial program 99.9%
distribute-lft-in99.9%
metadata-eval99.9%
associate-*r/99.9%
metadata-eval99.9%
Simplified99.9%
flip--99.9%
metadata-eval99.9%
add-sqr-sqrt100.0%
associate--r+100.0%
metadata-eval100.0%
Applied egg-rr100.0%
Taylor expanded in x around 0 99.5%
if 2 < (hypot.f64 1 x) Initial program 98.5%
distribute-lft-in98.5%
metadata-eval98.5%
associate-*r/98.5%
metadata-eval98.5%
Simplified98.5%
flip--98.5%
metadata-eval98.5%
add-sqr-sqrt100.0%
associate--r+100.0%
metadata-eval100.0%
Applied egg-rr100.0%
Taylor expanded in x around inf 98.6%
Final simplification99.0%
(FPCore (x) :precision binary64 (- 1.0 (sqrt (+ 0.5 (/ 0.5 (hypot 1.0 x))))))
double code(double x) {
return 1.0 - sqrt((0.5 + (0.5 / hypot(1.0, x))));
}
public static double code(double x) {
return 1.0 - Math.sqrt((0.5 + (0.5 / Math.hypot(1.0, x))));
}
def code(x): return 1.0 - math.sqrt((0.5 + (0.5 / math.hypot(1.0, x))))
function code(x) return Float64(1.0 - sqrt(Float64(0.5 + Float64(0.5 / hypot(1.0, x))))) end
function tmp = code(x) tmp = 1.0 - sqrt((0.5 + (0.5 / hypot(1.0, x)))); end
code[x_] := N[(1.0 - N[Sqrt[N[(0.5 + N[(0.5 / N[Sqrt[1.0 ^ 2 + x ^ 2], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]], $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
1 - \sqrt{0.5 + \frac{0.5}{\mathsf{hypot}\left(1, x\right)}}
\end{array}
Initial program 99.2%
distribute-lft-in99.2%
metadata-eval99.2%
associate-*r/99.2%
metadata-eval99.2%
Simplified99.2%
Final simplification99.2%
(FPCore (x) :precision binary64 (if (<= x 2e-13) 0.0 (/ 0.5 (+ 1.0 (sqrt 0.5)))))
double code(double x) {
double tmp;
if (x <= 2e-13) {
tmp = 0.0;
} else {
tmp = 0.5 / (1.0 + sqrt(0.5));
}
return tmp;
}
real(8) function code(x)
real(8), intent (in) :: x
real(8) :: tmp
if (x <= 2d-13) then
tmp = 0.0d0
else
tmp = 0.5d0 / (1.0d0 + sqrt(0.5d0))
end if
code = tmp
end function
public static double code(double x) {
double tmp;
if (x <= 2e-13) {
tmp = 0.0;
} else {
tmp = 0.5 / (1.0 + Math.sqrt(0.5));
}
return tmp;
}
def code(x): tmp = 0 if x <= 2e-13: tmp = 0.0 else: tmp = 0.5 / (1.0 + math.sqrt(0.5)) return tmp
function code(x) tmp = 0.0 if (x <= 2e-13) tmp = 0.0; else tmp = Float64(0.5 / Float64(1.0 + sqrt(0.5))); end return tmp end
function tmp_2 = code(x) tmp = 0.0; if (x <= 2e-13) tmp = 0.0; else tmp = 0.5 / (1.0 + sqrt(0.5)); end tmp_2 = tmp; end
code[x_] := If[LessEqual[x, 2e-13], 0.0, N[(0.5 / N[(1.0 + N[Sqrt[0.5], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]]
\begin{array}{l}
\\
\begin{array}{l}
\mathbf{if}\;x \leq 2 \cdot 10^{-13}:\\
\;\;\;\;0\\
\mathbf{else}:\\
\;\;\;\;\frac{0.5}{1 + \sqrt{0.5}}\\
\end{array}
\end{array}
if x < 2.0000000000000001e-13Initial program 99.5%
distribute-lft-in99.5%
metadata-eval99.5%
associate-*r/99.5%
metadata-eval99.5%
Simplified99.5%
Taylor expanded in x around 0 69.2%
if 2.0000000000000001e-13 < x Initial program 98.4%
distribute-lft-in98.4%
metadata-eval98.4%
associate-*r/98.4%
metadata-eval98.4%
Simplified98.4%
flip--98.3%
metadata-eval98.3%
add-sqr-sqrt99.9%
associate--r+99.9%
metadata-eval99.9%
Applied egg-rr99.9%
Taylor expanded in x around inf 97.7%
Final simplification76.7%
(FPCore (x) :precision binary64 (if (<= x 2e-13) 0.0 (- 1.0 (sqrt 0.5))))
double code(double x) {
double tmp;
if (x <= 2e-13) {
tmp = 0.0;
} else {
tmp = 1.0 - sqrt(0.5);
}
return tmp;
}
real(8) function code(x)
real(8), intent (in) :: x
real(8) :: tmp
if (x <= 2d-13) then
tmp = 0.0d0
else
tmp = 1.0d0 - sqrt(0.5d0)
end if
code = tmp
end function
public static double code(double x) {
double tmp;
if (x <= 2e-13) {
tmp = 0.0;
} else {
tmp = 1.0 - Math.sqrt(0.5);
}
return tmp;
}
def code(x): tmp = 0 if x <= 2e-13: tmp = 0.0 else: tmp = 1.0 - math.sqrt(0.5) return tmp
function code(x) tmp = 0.0 if (x <= 2e-13) tmp = 0.0; else tmp = Float64(1.0 - sqrt(0.5)); end return tmp end
function tmp_2 = code(x) tmp = 0.0; if (x <= 2e-13) tmp = 0.0; else tmp = 1.0 - sqrt(0.5); end tmp_2 = tmp; end
code[x_] := If[LessEqual[x, 2e-13], 0.0, N[(1.0 - N[Sqrt[0.5], $MachinePrecision]), $MachinePrecision]]
\begin{array}{l}
\\
\begin{array}{l}
\mathbf{if}\;x \leq 2 \cdot 10^{-13}:\\
\;\;\;\;0\\
\mathbf{else}:\\
\;\;\;\;1 - \sqrt{0.5}\\
\end{array}
\end{array}
if x < 2.0000000000000001e-13Initial program 99.5%
distribute-lft-in99.5%
metadata-eval99.5%
associate-*r/99.5%
metadata-eval99.5%
Simplified99.5%
Taylor expanded in x around 0 69.2%
if 2.0000000000000001e-13 < x Initial program 98.4%
distribute-lft-in98.4%
metadata-eval98.4%
associate-*r/98.4%
metadata-eval98.4%
Simplified98.4%
Taylor expanded in x around inf 96.2%
Final simplification76.3%
(FPCore (x) :precision binary64 (if (<= x 2e-13) 0.0 0.25))
double code(double x) {
double tmp;
if (x <= 2e-13) {
tmp = 0.0;
} else {
tmp = 0.25;
}
return tmp;
}
real(8) function code(x)
real(8), intent (in) :: x
real(8) :: tmp
if (x <= 2d-13) then
tmp = 0.0d0
else
tmp = 0.25d0
end if
code = tmp
end function
public static double code(double x) {
double tmp;
if (x <= 2e-13) {
tmp = 0.0;
} else {
tmp = 0.25;
}
return tmp;
}
def code(x): tmp = 0 if x <= 2e-13: tmp = 0.0 else: tmp = 0.25 return tmp
function code(x) tmp = 0.0 if (x <= 2e-13) tmp = 0.0; else tmp = 0.25; end return tmp end
function tmp_2 = code(x) tmp = 0.0; if (x <= 2e-13) tmp = 0.0; else tmp = 0.25; end tmp_2 = tmp; end
code[x_] := If[LessEqual[x, 2e-13], 0.0, 0.25]
\begin{array}{l}
\\
\begin{array}{l}
\mathbf{if}\;x \leq 2 \cdot 10^{-13}:\\
\;\;\;\;0\\
\mathbf{else}:\\
\;\;\;\;0.25\\
\end{array}
\end{array}
if x < 2.0000000000000001e-13Initial program 99.5%
distribute-lft-in99.5%
metadata-eval99.5%
associate-*r/99.5%
metadata-eval99.5%
Simplified99.5%
Taylor expanded in x around 0 69.2%
if 2.0000000000000001e-13 < x Initial program 98.4%
distribute-lft-in98.4%
metadata-eval98.4%
associate-*r/98.4%
metadata-eval98.4%
Simplified98.4%
flip--98.3%
metadata-eval98.3%
add-sqr-sqrt99.9%
associate--r+99.9%
metadata-eval99.9%
Applied egg-rr99.9%
Taylor expanded in x around 0 22.9%
Taylor expanded in x around inf 22.6%
Final simplification57.0%
(FPCore (x) :precision binary64 0.0)
double code(double x) {
return 0.0;
}
real(8) function code(x)
real(8), intent (in) :: x
code = 0.0d0
end function
public static double code(double x) {
return 0.0;
}
def code(x): return 0.0
function code(x) return 0.0 end
function tmp = code(x) tmp = 0.0; end
code[x_] := 0.0
\begin{array}{l}
\\
0
\end{array}
Initial program 99.2%
distribute-lft-in99.2%
metadata-eval99.2%
associate-*r/99.2%
metadata-eval99.2%
Simplified99.2%
Taylor expanded in x around 0 51.9%
Final simplification51.9%
herbie shell --seed 2024052
(FPCore (x)
:name "Given's Rotation SVD example, simplified"
:precision binary64
(- 1.0 (sqrt (* 0.5 (+ 1.0 (/ 1.0 (hypot 1.0 x)))))))