
(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 (/ 0.5 (hypot 1.0 x))))) (/ (/ (- 0.25 (/ 0.25 (fma x x 1.0))) t_0) (+ 1.0 (sqrt t_0)))))
double code(double x) {
double t_0 = 0.5 + (0.5 / hypot(1.0, x));
return ((0.25 - (0.25 / fma(x, x, 1.0))) / t_0) / (1.0 + sqrt(t_0));
}
function code(x) t_0 = Float64(0.5 + Float64(0.5 / hypot(1.0, x))) return Float64(Float64(Float64(0.25 - Float64(0.25 / fma(x, x, 1.0))) / t_0) / Float64(1.0 + sqrt(t_0))) end
code[x_] := Block[{t$95$0 = N[(0.5 + N[(0.5 / N[Sqrt[1.0 ^ 2 + x ^ 2], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]}, N[(N[(N[(0.25 - N[(0.25 / N[(x * x + 1.0), $MachinePrecision]), $MachinePrecision]), $MachinePrecision] / t$95$0), $MachinePrecision] / N[(1.0 + N[Sqrt[t$95$0], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]]
\begin{array}{l}
\\
\begin{array}{l}
t_0 := 0.5 + \frac{0.5}{\mathsf{hypot}\left(1, x\right)}\\
\frac{\frac{0.25 - \frac{0.25}{\mathsf{fma}\left(x, x, 1\right)}}{t\_0}}{1 + \sqrt{t\_0}}
\end{array}
\end{array}
Initial program 98.4%
distribute-lft-in98.4%
metadata-eval98.4%
associate-*r/98.4%
metadata-eval98.4%
Simplified98.4%
flip--98.4%
metadata-eval98.4%
add-sqr-sqrt99.9%
associate--r+99.9%
metadata-eval99.9%
Applied egg-rr99.9%
add-sqr-sqrt99.9%
sqrt-unprod99.9%
frac-times99.9%
metadata-eval99.9%
hypot-undefine99.9%
hypot-undefine99.9%
rem-square-sqrt99.9%
metadata-eval99.9%
+-commutative99.9%
fma-define99.9%
Applied egg-rr99.9%
sqrt-div99.9%
metadata-eval99.9%
fma-undefine99.9%
+-commutative99.9%
hypot-1-def99.9%
flip--99.9%
metadata-eval99.9%
frac-times99.9%
metadata-eval99.9%
hypot-undefine99.9%
hypot-undefine99.9%
rem-square-sqrt99.9%
metadata-eval99.9%
+-commutative99.9%
fma-undefine99.9%
Applied egg-rr99.9%
Final simplification99.9%
(FPCore (x) :precision binary64 (/ (- 0.5 (sqrt (/ 0.25 (fma x x 1.0)))) (+ 1.0 (sqrt (+ 0.5 (/ 0.5 (hypot 1.0 x)))))))
double code(double x) {
return (0.5 - sqrt((0.25 / fma(x, x, 1.0)))) / (1.0 + sqrt((0.5 + (0.5 / hypot(1.0, x)))));
}
function code(x) return Float64(Float64(0.5 - sqrt(Float64(0.25 / fma(x, x, 1.0)))) / Float64(1.0 + sqrt(Float64(0.5 + Float64(0.5 / hypot(1.0, x)))))) end
code[x_] := N[(N[(0.5 - N[Sqrt[N[(0.25 / N[(x * x + 1.0), $MachinePrecision]), $MachinePrecision]], $MachinePrecision]), $MachinePrecision] / N[(1.0 + N[Sqrt[N[(0.5 + N[(0.5 / N[Sqrt[1.0 ^ 2 + x ^ 2], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
\frac{0.5 - \sqrt{\frac{0.25}{\mathsf{fma}\left(x, x, 1\right)}}}{1 + \sqrt{0.5 + \frac{0.5}{\mathsf{hypot}\left(1, x\right)}}}
\end{array}
Initial program 98.4%
distribute-lft-in98.4%
metadata-eval98.4%
associate-*r/98.4%
metadata-eval98.4%
Simplified98.4%
flip--98.4%
metadata-eval98.4%
add-sqr-sqrt99.9%
associate--r+99.9%
metadata-eval99.9%
Applied egg-rr99.9%
add-sqr-sqrt99.9%
sqrt-unprod99.9%
frac-times99.9%
metadata-eval99.9%
hypot-undefine99.9%
hypot-undefine99.9%
rem-square-sqrt99.9%
metadata-eval99.9%
+-commutative99.9%
fma-define99.9%
Applied egg-rr99.9%
Final simplification99.9%
(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 98.4%
distribute-lft-in98.4%
metadata-eval98.4%
associate-*r/98.4%
metadata-eval98.4%
Simplified98.4%
flip--98.4%
metadata-eval98.4%
add-sqr-sqrt99.9%
associate--r+99.9%
metadata-eval99.9%
Applied egg-rr99.9%
Final simplification99.9%
(FPCore (x) :precision binary64 (/ (- 0.5 (/ 0.5 (hypot 1.0 x))) (+ 1.0 (sqrt (+ 0.5 (/ 0.5 x))))))
double code(double x) {
return (0.5 - (0.5 / hypot(1.0, x))) / (1.0 + sqrt((0.5 + (0.5 / x))));
}
public static double code(double x) {
return (0.5 - (0.5 / Math.hypot(1.0, x))) / (1.0 + Math.sqrt((0.5 + (0.5 / x))));
}
def code(x): return (0.5 - (0.5 / math.hypot(1.0, x))) / (1.0 + math.sqrt((0.5 + (0.5 / x))))
function code(x) return Float64(Float64(0.5 - Float64(0.5 / hypot(1.0, x))) / Float64(1.0 + sqrt(Float64(0.5 + Float64(0.5 / x))))) end
function tmp = code(x) tmp = (0.5 - (0.5 / hypot(1.0, x))) / (1.0 + sqrt((0.5 + (0.5 / x)))); end
code[x_] := N[(N[(0.5 - N[(0.5 / N[Sqrt[1.0 ^ 2 + x ^ 2], $MachinePrecision]), $MachinePrecision]), $MachinePrecision] / N[(1.0 + N[Sqrt[N[(0.5 + N[(0.5 / x), $MachinePrecision]), $MachinePrecision]], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
\frac{0.5 - \frac{0.5}{\mathsf{hypot}\left(1, x\right)}}{1 + \sqrt{0.5 + \frac{0.5}{x}}}
\end{array}
Initial program 98.4%
distribute-lft-in98.4%
metadata-eval98.4%
associate-*r/98.4%
metadata-eval98.4%
Simplified98.4%
flip--98.4%
metadata-eval98.4%
add-sqr-sqrt99.9%
associate--r+99.9%
metadata-eval99.9%
Applied egg-rr99.9%
Taylor expanded in x around inf 97.8%
Final simplification97.8%
(FPCore (x) :precision binary64 (/ (- 0.5 (/ 0.5 x)) (+ 1.0 (sqrt (+ 0.5 (/ 0.5 x))))))
double code(double x) {
return (0.5 - (0.5 / x)) / (1.0 + sqrt((0.5 + (0.5 / x))));
}
real(8) function code(x)
real(8), intent (in) :: x
code = (0.5d0 - (0.5d0 / x)) / (1.0d0 + sqrt((0.5d0 + (0.5d0 / x))))
end function
public static double code(double x) {
return (0.5 - (0.5 / x)) / (1.0 + Math.sqrt((0.5 + (0.5 / x))));
}
def code(x): return (0.5 - (0.5 / x)) / (1.0 + math.sqrt((0.5 + (0.5 / x))))
function code(x) return Float64(Float64(0.5 - Float64(0.5 / x)) / Float64(1.0 + sqrt(Float64(0.5 + Float64(0.5 / x))))) end
function tmp = code(x) tmp = (0.5 - (0.5 / x)) / (1.0 + sqrt((0.5 + (0.5 / x)))); end
code[x_] := N[(N[(0.5 - N[(0.5 / x), $MachinePrecision]), $MachinePrecision] / N[(1.0 + N[Sqrt[N[(0.5 + N[(0.5 / x), $MachinePrecision]), $MachinePrecision]], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
\frac{0.5 - \frac{0.5}{x}}{1 + \sqrt{0.5 + \frac{0.5}{x}}}
\end{array}
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 96.1%
flip--96.1%
metadata-eval96.1%
add-sqr-sqrt97.6%
associate--r+97.6%
metadata-eval97.6%
Applied egg-rr97.6%
Final simplification97.6%
(FPCore (x) :precision binary64 (/ 0.5 (+ 1.0 (sqrt 0.5))))
double code(double x) {
return 0.5 / (1.0 + sqrt(0.5));
}
real(8) function code(x)
real(8), intent (in) :: x
code = 0.5d0 / (1.0d0 + sqrt(0.5d0))
end function
public static double code(double x) {
return 0.5 / (1.0 + Math.sqrt(0.5));
}
def code(x): return 0.5 / (1.0 + math.sqrt(0.5))
function code(x) return Float64(0.5 / Float64(1.0 + sqrt(0.5))) end
function tmp = code(x) tmp = 0.5 / (1.0 + sqrt(0.5)); end
code[x_] := N[(0.5 / N[(1.0 + N[Sqrt[0.5], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
\frac{0.5}{1 + \sqrt{0.5}}
\end{array}
Initial program 98.4%
distribute-lft-in98.4%
metadata-eval98.4%
associate-*r/98.4%
metadata-eval98.4%
Simplified98.4%
flip--98.4%
metadata-eval98.4%
add-sqr-sqrt99.9%
associate--r+99.9%
metadata-eval99.9%
Applied egg-rr99.9%
Taylor expanded in x around inf 97.0%
Final simplification97.0%
(FPCore (x) :precision binary64 (- 1.0 (sqrt 0.5)))
double code(double x) {
return 1.0 - sqrt(0.5);
}
real(8) function code(x)
real(8), intent (in) :: x
code = 1.0d0 - sqrt(0.5d0)
end function
public static double code(double x) {
return 1.0 - Math.sqrt(0.5);
}
def code(x): return 1.0 - math.sqrt(0.5)
function code(x) return Float64(1.0 - sqrt(0.5)) end
function tmp = code(x) tmp = 1.0 - sqrt(0.5); end
code[x_] := N[(1.0 - N[Sqrt[0.5], $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
1 - \sqrt{0.5}
\end{array}
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 95.5%
Final simplification95.5%
(FPCore (x) :precision binary64 1.0)
double code(double x) {
return 1.0;
}
real(8) function code(x)
real(8), intent (in) :: x
code = 1.0d0
end function
public static double code(double x) {
return 1.0;
}
def code(x): return 1.0
function code(x) return 1.0 end
function tmp = code(x) tmp = 1.0; end
code[x_] := 1.0
\begin{array}{l}
\\
1
\end{array}
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 96.1%
Taylor expanded in x around 0 17.3%
Final simplification17.3%
herbie shell --seed 2024062
(FPCore (x)
:name "Given's Rotation SVD example, simplified"
:precision binary64
(- 1.0 (sqrt (* 0.5 (+ 1.0 (/ 1.0 (hypot 1.0 x)))))))