
(FPCore (p x) :precision binary64 (sqrt (* 0.5 (+ 1.0 (/ x (sqrt (+ (* (* 4.0 p) p) (* x x))))))))
double code(double p, double x) {
return sqrt((0.5 * (1.0 + (x / sqrt((((4.0 * p) * p) + (x * x)))))));
}
real(8) function code(p, x)
real(8), intent (in) :: p
real(8), intent (in) :: x
code = sqrt((0.5d0 * (1.0d0 + (x / sqrt((((4.0d0 * p) * p) + (x * x)))))))
end function
public static double code(double p, double x) {
return Math.sqrt((0.5 * (1.0 + (x / Math.sqrt((((4.0 * p) * p) + (x * x)))))));
}
def code(p, x): return math.sqrt((0.5 * (1.0 + (x / math.sqrt((((4.0 * p) * p) + (x * x)))))))
function code(p, x) return sqrt(Float64(0.5 * Float64(1.0 + Float64(x / sqrt(Float64(Float64(Float64(4.0 * p) * p) + Float64(x * x))))))) end
function tmp = code(p, x) tmp = sqrt((0.5 * (1.0 + (x / sqrt((((4.0 * p) * p) + (x * x))))))); end
code[p_, x_] := N[Sqrt[N[(0.5 * N[(1.0 + N[(x / N[Sqrt[N[(N[(N[(4.0 * p), $MachinePrecision] * p), $MachinePrecision] + N[(x * x), $MachinePrecision]), $MachinePrecision]], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]], $MachinePrecision]
\begin{array}{l}
\\
\sqrt{0.5 \cdot \left(1 + \frac{x}{\sqrt{\left(4 \cdot p\right) \cdot p + x \cdot x}}\right)}
\end{array}
Sampling outcomes in binary64 precision:
Herbie found 5 alternatives:
| Alternative | Accuracy | Speedup |
|---|
(FPCore (p x) :precision binary64 (sqrt (* 0.5 (+ 1.0 (/ x (sqrt (+ (* (* 4.0 p) p) (* x x))))))))
double code(double p, double x) {
return sqrt((0.5 * (1.0 + (x / sqrt((((4.0 * p) * p) + (x * x)))))));
}
real(8) function code(p, x)
real(8), intent (in) :: p
real(8), intent (in) :: x
code = sqrt((0.5d0 * (1.0d0 + (x / sqrt((((4.0d0 * p) * p) + (x * x)))))))
end function
public static double code(double p, double x) {
return Math.sqrt((0.5 * (1.0 + (x / Math.sqrt((((4.0 * p) * p) + (x * x)))))));
}
def code(p, x): return math.sqrt((0.5 * (1.0 + (x / math.sqrt((((4.0 * p) * p) + (x * x)))))))
function code(p, x) return sqrt(Float64(0.5 * Float64(1.0 + Float64(x / sqrt(Float64(Float64(Float64(4.0 * p) * p) + Float64(x * x))))))) end
function tmp = code(p, x) tmp = sqrt((0.5 * (1.0 + (x / sqrt((((4.0 * p) * p) + (x * x))))))); end
code[p_, x_] := N[Sqrt[N[(0.5 * N[(1.0 + N[(x / N[Sqrt[N[(N[(N[(4.0 * p), $MachinePrecision] * p), $MachinePrecision] + N[(x * x), $MachinePrecision]), $MachinePrecision]], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]], $MachinePrecision]
\begin{array}{l}
\\
\sqrt{0.5 \cdot \left(1 + \frac{x}{\sqrt{\left(4 \cdot p\right) \cdot p + x \cdot x}}\right)}
\end{array}
p_m = (fabs.f64 p) (FPCore (p_m x) :precision binary64 (if (<= (/ x (sqrt (+ (* p_m (* 4.0 p_m)) (* x x)))) -1.0) (/ p_m (- x)) (cbrt (pow (+ 0.5 (/ (* x 0.5) (hypot x (* p_m 2.0)))) 1.5))))
p_m = fabs(p);
double code(double p_m, double x) {
double tmp;
if ((x / sqrt(((p_m * (4.0 * p_m)) + (x * x)))) <= -1.0) {
tmp = p_m / -x;
} else {
tmp = cbrt(pow((0.5 + ((x * 0.5) / hypot(x, (p_m * 2.0)))), 1.5));
}
return tmp;
}
p_m = Math.abs(p);
public static double code(double p_m, double x) {
double tmp;
if ((x / Math.sqrt(((p_m * (4.0 * p_m)) + (x * x)))) <= -1.0) {
tmp = p_m / -x;
} else {
tmp = Math.cbrt(Math.pow((0.5 + ((x * 0.5) / Math.hypot(x, (p_m * 2.0)))), 1.5));
}
return tmp;
}
p_m = abs(p) function code(p_m, x) tmp = 0.0 if (Float64(x / sqrt(Float64(Float64(p_m * Float64(4.0 * p_m)) + Float64(x * x)))) <= -1.0) tmp = Float64(p_m / Float64(-x)); else tmp = cbrt((Float64(0.5 + Float64(Float64(x * 0.5) / hypot(x, Float64(p_m * 2.0)))) ^ 1.5)); end return tmp end
p_m = N[Abs[p], $MachinePrecision] code[p$95$m_, x_] := If[LessEqual[N[(x / N[Sqrt[N[(N[(p$95$m * N[(4.0 * p$95$m), $MachinePrecision]), $MachinePrecision] + N[(x * x), $MachinePrecision]), $MachinePrecision]], $MachinePrecision]), $MachinePrecision], -1.0], N[(p$95$m / (-x)), $MachinePrecision], N[Power[N[Power[N[(0.5 + N[(N[(x * 0.5), $MachinePrecision] / N[Sqrt[x ^ 2 + N[(p$95$m * 2.0), $MachinePrecision] ^ 2], $MachinePrecision]), $MachinePrecision]), $MachinePrecision], 1.5], $MachinePrecision], 1/3], $MachinePrecision]]
\begin{array}{l}
p_m = \left|p\right|
\\
\begin{array}{l}
\mathbf{if}\;\frac{x}{\sqrt{p\_m \cdot \left(4 \cdot p\_m\right) + x \cdot x}} \leq -1:\\
\;\;\;\;\frac{p\_m}{-x}\\
\mathbf{else}:\\
\;\;\;\;\sqrt[3]{{\left(0.5 + \frac{x \cdot 0.5}{\mathsf{hypot}\left(x, p\_m \cdot 2\right)}\right)}^{1.5}}\\
\end{array}
\end{array}
if (/.f64 x (sqrt.f64 (+.f64 (*.f64 (*.f64 #s(literal 4 binary64) p) p) (*.f64 x x)))) < -1Initial program 16.0%
add-cbrt-cube16.0%
pow1/316.0%
Applied egg-rr16.0%
unpow1/316.0%
Simplified16.0%
Taylor expanded in x around -inf 58.9%
mul-1-neg58.9%
distribute-neg-frac258.9%
Simplified58.9%
if -1 < (/.f64 x (sqrt.f64 (+.f64 (*.f64 (*.f64 #s(literal 4 binary64) p) p) (*.f64 x x)))) Initial program 100.0%
add-cbrt-cube100.0%
pow1/3100.0%
Applied egg-rr100.0%
unpow1/3100.0%
Simplified100.0%
fma-undefine100.0%
associate-*l/100.0%
hypot-undefine100.0%
+-commutative100.0%
hypot-undefine100.0%
associate-*l/100.0%
*-commutative100.0%
associate-*r/100.0%
hypot-undefine100.0%
+-commutative100.0%
hypot-undefine100.0%
Applied egg-rr100.0%
Final simplification91.3%
p_m = (fabs.f64 p) (FPCore (p_m x) :precision binary64 (if (<= (/ x (sqrt (+ (* p_m (* 4.0 p_m)) (* x x)))) -1.0) (/ p_m (- x)) (sqrt (* 0.5 (+ 1.0 (/ x (hypot (* p_m 2.0) x)))))))
p_m = fabs(p);
double code(double p_m, double x) {
double tmp;
if ((x / sqrt(((p_m * (4.0 * p_m)) + (x * x)))) <= -1.0) {
tmp = p_m / -x;
} else {
tmp = sqrt((0.5 * (1.0 + (x / hypot((p_m * 2.0), x)))));
}
return tmp;
}
p_m = Math.abs(p);
public static double code(double p_m, double x) {
double tmp;
if ((x / Math.sqrt(((p_m * (4.0 * p_m)) + (x * x)))) <= -1.0) {
tmp = p_m / -x;
} else {
tmp = Math.sqrt((0.5 * (1.0 + (x / Math.hypot((p_m * 2.0), x)))));
}
return tmp;
}
p_m = math.fabs(p) def code(p_m, x): tmp = 0 if (x / math.sqrt(((p_m * (4.0 * p_m)) + (x * x)))) <= -1.0: tmp = p_m / -x else: tmp = math.sqrt((0.5 * (1.0 + (x / math.hypot((p_m * 2.0), x))))) return tmp
p_m = abs(p) function code(p_m, x) tmp = 0.0 if (Float64(x / sqrt(Float64(Float64(p_m * Float64(4.0 * p_m)) + Float64(x * x)))) <= -1.0) tmp = Float64(p_m / Float64(-x)); else tmp = sqrt(Float64(0.5 * Float64(1.0 + Float64(x / hypot(Float64(p_m * 2.0), x))))); end return tmp end
p_m = abs(p); function tmp_2 = code(p_m, x) tmp = 0.0; if ((x / sqrt(((p_m * (4.0 * p_m)) + (x * x)))) <= -1.0) tmp = p_m / -x; else tmp = sqrt((0.5 * (1.0 + (x / hypot((p_m * 2.0), x))))); end tmp_2 = tmp; end
p_m = N[Abs[p], $MachinePrecision] code[p$95$m_, x_] := If[LessEqual[N[(x / N[Sqrt[N[(N[(p$95$m * N[(4.0 * p$95$m), $MachinePrecision]), $MachinePrecision] + N[(x * x), $MachinePrecision]), $MachinePrecision]], $MachinePrecision]), $MachinePrecision], -1.0], N[(p$95$m / (-x)), $MachinePrecision], N[Sqrt[N[(0.5 * N[(1.0 + N[(x / N[Sqrt[N[(p$95$m * 2.0), $MachinePrecision] ^ 2 + x ^ 2], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]], $MachinePrecision]]
\begin{array}{l}
p_m = \left|p\right|
\\
\begin{array}{l}
\mathbf{if}\;\frac{x}{\sqrt{p\_m \cdot \left(4 \cdot p\_m\right) + x \cdot x}} \leq -1:\\
\;\;\;\;\frac{p\_m}{-x}\\
\mathbf{else}:\\
\;\;\;\;\sqrt{0.5 \cdot \left(1 + \frac{x}{\mathsf{hypot}\left(p\_m \cdot 2, x\right)}\right)}\\
\end{array}
\end{array}
if (/.f64 x (sqrt.f64 (+.f64 (*.f64 (*.f64 #s(literal 4 binary64) p) p) (*.f64 x x)))) < -1Initial program 16.0%
add-cbrt-cube16.0%
pow1/316.0%
Applied egg-rr16.0%
unpow1/316.0%
Simplified16.0%
Taylor expanded in x around -inf 58.9%
mul-1-neg58.9%
distribute-neg-frac258.9%
Simplified58.9%
if -1 < (/.f64 x (sqrt.f64 (+.f64 (*.f64 (*.f64 #s(literal 4 binary64) p) p) (*.f64 x x)))) Initial program 100.0%
add-sqr-sqrt100.0%
hypot-define100.0%
associate-*l*100.0%
sqrt-prod100.0%
metadata-eval100.0%
sqrt-unprod48.5%
add-sqr-sqrt100.0%
Applied egg-rr100.0%
Final simplification91.3%
p_m = (fabs.f64 p) (FPCore (p_m x) :precision binary64 (if (<= p_m 2.7e-64) 1.0 (sqrt 0.5)))
p_m = fabs(p);
double code(double p_m, double x) {
double tmp;
if (p_m <= 2.7e-64) {
tmp = 1.0;
} else {
tmp = sqrt(0.5);
}
return tmp;
}
p_m = abs(p)
real(8) function code(p_m, x)
real(8), intent (in) :: p_m
real(8), intent (in) :: x
real(8) :: tmp
if (p_m <= 2.7d-64) then
tmp = 1.0d0
else
tmp = sqrt(0.5d0)
end if
code = tmp
end function
p_m = Math.abs(p);
public static double code(double p_m, double x) {
double tmp;
if (p_m <= 2.7e-64) {
tmp = 1.0;
} else {
tmp = Math.sqrt(0.5);
}
return tmp;
}
p_m = math.fabs(p) def code(p_m, x): tmp = 0 if p_m <= 2.7e-64: tmp = 1.0 else: tmp = math.sqrt(0.5) return tmp
p_m = abs(p) function code(p_m, x) tmp = 0.0 if (p_m <= 2.7e-64) tmp = 1.0; else tmp = sqrt(0.5); end return tmp end
p_m = abs(p); function tmp_2 = code(p_m, x) tmp = 0.0; if (p_m <= 2.7e-64) tmp = 1.0; else tmp = sqrt(0.5); end tmp_2 = tmp; end
p_m = N[Abs[p], $MachinePrecision] code[p$95$m_, x_] := If[LessEqual[p$95$m, 2.7e-64], 1.0, N[Sqrt[0.5], $MachinePrecision]]
\begin{array}{l}
p_m = \left|p\right|
\\
\begin{array}{l}
\mathbf{if}\;p\_m \leq 2.7 \cdot 10^{-64}:\\
\;\;\;\;1\\
\mathbf{else}:\\
\;\;\;\;\sqrt{0.5}\\
\end{array}
\end{array}
if p < 2.69999999999999986e-64Initial program 80.9%
add-cbrt-cube80.9%
pow1/380.9%
Applied egg-rr80.9%
unpow1/380.9%
Simplified80.9%
fma-undefine80.9%
associate-*l/80.9%
hypot-undefine80.9%
+-commutative80.9%
hypot-undefine80.9%
associate-*l/80.9%
*-commutative80.9%
associate-*r/80.9%
hypot-undefine80.9%
+-commutative80.9%
hypot-undefine80.9%
Applied egg-rr80.9%
Taylor expanded in x around inf 40.4%
if 2.69999999999999986e-64 < p Initial program 85.3%
Taylor expanded in x around 0 78.4%
Final simplification52.1%
p_m = (fabs.f64 p) (FPCore (p_m x) :precision binary64 (if (<= x -3.8e-73) (/ p_m (- x)) 1.0))
p_m = fabs(p);
double code(double p_m, double x) {
double tmp;
if (x <= -3.8e-73) {
tmp = p_m / -x;
} else {
tmp = 1.0;
}
return tmp;
}
p_m = abs(p)
real(8) function code(p_m, x)
real(8), intent (in) :: p_m
real(8), intent (in) :: x
real(8) :: tmp
if (x <= (-3.8d-73)) then
tmp = p_m / -x
else
tmp = 1.0d0
end if
code = tmp
end function
p_m = Math.abs(p);
public static double code(double p_m, double x) {
double tmp;
if (x <= -3.8e-73) {
tmp = p_m / -x;
} else {
tmp = 1.0;
}
return tmp;
}
p_m = math.fabs(p) def code(p_m, x): tmp = 0 if x <= -3.8e-73: tmp = p_m / -x else: tmp = 1.0 return tmp
p_m = abs(p) function code(p_m, x) tmp = 0.0 if (x <= -3.8e-73) tmp = Float64(p_m / Float64(-x)); else tmp = 1.0; end return tmp end
p_m = abs(p); function tmp_2 = code(p_m, x) tmp = 0.0; if (x <= -3.8e-73) tmp = p_m / -x; else tmp = 1.0; end tmp_2 = tmp; end
p_m = N[Abs[p], $MachinePrecision] code[p$95$m_, x_] := If[LessEqual[x, -3.8e-73], N[(p$95$m / (-x)), $MachinePrecision], 1.0]
\begin{array}{l}
p_m = \left|p\right|
\\
\begin{array}{l}
\mathbf{if}\;x \leq -3.8 \cdot 10^{-73}:\\
\;\;\;\;\frac{p\_m}{-x}\\
\mathbf{else}:\\
\;\;\;\;1\\
\end{array}
\end{array}
if x < -3.8000000000000003e-73Initial program 55.8%
add-cbrt-cube55.8%
pow1/355.8%
Applied egg-rr55.8%
unpow1/355.8%
Simplified55.8%
Taylor expanded in x around -inf 35.1%
mul-1-neg35.1%
distribute-neg-frac235.1%
Simplified35.1%
if -3.8000000000000003e-73 < x Initial program 97.6%
add-cbrt-cube97.6%
pow1/397.6%
Applied egg-rr97.6%
unpow1/397.6%
Simplified97.6%
fma-undefine97.6%
associate-*l/97.6%
hypot-undefine97.6%
+-commutative97.6%
hypot-undefine97.6%
associate-*l/97.6%
*-commutative97.6%
associate-*r/97.6%
hypot-undefine97.6%
+-commutative97.6%
hypot-undefine97.6%
Applied egg-rr97.6%
Taylor expanded in x around inf 49.3%
Final simplification44.1%
p_m = (fabs.f64 p) (FPCore (p_m x) :precision binary64 (/ p_m (- x)))
p_m = fabs(p);
double code(double p_m, double x) {
return p_m / -x;
}
p_m = abs(p)
real(8) function code(p_m, x)
real(8), intent (in) :: p_m
real(8), intent (in) :: x
code = p_m / -x
end function
p_m = Math.abs(p);
public static double code(double p_m, double x) {
return p_m / -x;
}
p_m = math.fabs(p) def code(p_m, x): return p_m / -x
p_m = abs(p) function code(p_m, x) return Float64(p_m / Float64(-x)) end
p_m = abs(p); function tmp = code(p_m, x) tmp = p_m / -x; end
p_m = N[Abs[p], $MachinePrecision] code[p$95$m_, x_] := N[(p$95$m / (-x)), $MachinePrecision]
\begin{array}{l}
p_m = \left|p\right|
\\
\frac{p\_m}{-x}
\end{array}
Initial program 82.3%
add-cbrt-cube82.2%
pow1/382.3%
Applied egg-rr82.3%
unpow1/382.3%
Simplified82.3%
Taylor expanded in x around -inf 14.9%
mul-1-neg14.9%
distribute-neg-frac214.9%
Simplified14.9%
Final simplification14.9%
(FPCore (p x) :precision binary64 (sqrt (+ 0.5 (/ (copysign 0.5 x) (hypot 1.0 (/ (* 2.0 p) x))))))
double code(double p, double x) {
return sqrt((0.5 + (copysign(0.5, x) / hypot(1.0, ((2.0 * p) / x)))));
}
public static double code(double p, double x) {
return Math.sqrt((0.5 + (Math.copySign(0.5, x) / Math.hypot(1.0, ((2.0 * p) / x)))));
}
def code(p, x): return math.sqrt((0.5 + (math.copysign(0.5, x) / math.hypot(1.0, ((2.0 * p) / x)))))
function code(p, x) return sqrt(Float64(0.5 + Float64(copysign(0.5, x) / hypot(1.0, Float64(Float64(2.0 * p) / x))))) end
function tmp = code(p, x) tmp = sqrt((0.5 + ((sign(x) * abs(0.5)) / hypot(1.0, ((2.0 * p) / x))))); end
code[p_, x_] := N[Sqrt[N[(0.5 + N[(N[With[{TMP1 = Abs[0.5], TMP2 = Sign[x]}, TMP1 * If[TMP2 == 0, 1, TMP2]], $MachinePrecision] / N[Sqrt[1.0 ^ 2 + N[(N[(2.0 * p), $MachinePrecision] / x), $MachinePrecision] ^ 2], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]], $MachinePrecision]
\begin{array}{l}
\\
\sqrt{0.5 + \frac{\mathsf{copysign}\left(0.5, x\right)}{\mathsf{hypot}\left(1, \frac{2 \cdot p}{x}\right)}}
\end{array}
herbie shell --seed 2024084
(FPCore (p x)
:name "Given's Rotation SVD example"
:precision binary64
:pre (and (< 1e-150 (fabs x)) (< (fabs x) 1e+150))
:alt
(sqrt (+ 0.5 (/ (copysign 0.5 x) (hypot 1.0 (/ (* 2.0 p) x)))))
(sqrt (* 0.5 (+ 1.0 (/ x (sqrt (+ (* (* 4.0 p) p) (* x x))))))))