
(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 6 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)))) -0.5) (/ p_m (- x)) (sqrt (* 0.5 (+ -1.0 (+ 2.0 (/ x (hypot x (* p_m 2.0)))))))))
p_m = fabs(p);
double code(double p_m, double x) {
double tmp;
if ((x / sqrt(((p_m * (4.0 * p_m)) + (x * x)))) <= -0.5) {
tmp = p_m / -x;
} else {
tmp = sqrt((0.5 * (-1.0 + (2.0 + (x / hypot(x, (p_m * 2.0)))))));
}
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)))) <= -0.5) {
tmp = p_m / -x;
} else {
tmp = Math.sqrt((0.5 * (-1.0 + (2.0 + (x / Math.hypot(x, (p_m * 2.0)))))));
}
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)))) <= -0.5: tmp = p_m / -x else: tmp = math.sqrt((0.5 * (-1.0 + (2.0 + (x / math.hypot(x, (p_m * 2.0))))))) 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)))) <= -0.5) tmp = Float64(p_m / Float64(-x)); else tmp = sqrt(Float64(0.5 * Float64(-1.0 + Float64(2.0 + Float64(x / hypot(x, Float64(p_m * 2.0))))))); 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)))) <= -0.5) tmp = p_m / -x; else tmp = sqrt((0.5 * (-1.0 + (2.0 + (x / hypot(x, (p_m * 2.0))))))); 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], -0.5], N[(p$95$m / (-x)), $MachinePrecision], N[Sqrt[N[(0.5 * N[(-1.0 + N[(2.0 + N[(x / N[Sqrt[x ^ 2 + N[(p$95$m * 2.0), $MachinePrecision] ^ 2], $MachinePrecision]), $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 -0.5:\\
\;\;\;\;\frac{p\_m}{-x}\\
\mathbf{else}:\\
\;\;\;\;\sqrt{0.5 \cdot \left(-1 + \left(2 + \frac{x}{\mathsf{hypot}\left(x, p\_m \cdot 2\right)}\right)\right)}\\
\end{array}
\end{array}
if (/.f64 x (sqrt.f64 (+.f64 (*.f64 (*.f64 #s(literal 4 binary64) p) p) (*.f64 x x)))) < -0.5Initial program 19.8%
Taylor expanded in x around -inf 53.2%
associate-*r/53.2%
Simplified53.2%
Applied egg-rr60.7%
if -0.5 < (/.f64 x (sqrt.f64 (+.f64 (*.f64 (*.f64 #s(literal 4 binary64) p) p) (*.f64 x x)))) Initial program 100.0%
expm1-log1p-u99.4%
expm1-undefine99.4%
+-commutative99.4%
add-sqr-sqrt99.4%
hypot-define99.4%
associate-*l*99.4%
sqrt-prod99.4%
metadata-eval99.4%
sqrt-unprod48.4%
add-sqr-sqrt99.4%
Applied egg-rr99.4%
sub-neg99.4%
metadata-eval99.4%
+-commutative99.4%
log1p-undefine100.0%
rem-exp-log100.0%
associate-+r+100.0%
metadata-eval100.0%
*-commutative100.0%
Simplified100.0%
Final simplification90.3%
p_m = (fabs.f64 p) (FPCore (p_m x) :precision binary64 (if (<= x -3.3e-47) (/ 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 <= -3.3e-47) {
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 <= -3.3e-47) {
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 <= -3.3e-47: 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 (x <= -3.3e-47) 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 <= -3.3e-47) 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[x, -3.3e-47], 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}\;x \leq -3.3 \cdot 10^{-47}:\\
\;\;\;\;\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 x < -3.30000000000000004e-47Initial program 45.4%
Taylor expanded in x around -inf 43.4%
associate-*r/43.4%
Simplified43.4%
Applied egg-rr47.4%
if -3.30000000000000004e-47 < x Initial program 93.1%
add-sqr-sqrt93.1%
hypot-define93.1%
associate-*l*93.1%
sqrt-prod93.1%
metadata-eval93.1%
sqrt-unprod46.1%
add-sqr-sqrt93.1%
Applied egg-rr93.1%
Final simplification80.8%
p_m = (fabs.f64 p) (FPCore (p_m x) :precision binary64 (if (<= x -5.2e-46) (/ p_m (- x)) (if (<= x 1e-9) (sqrt 0.5) 1.0)))
p_m = fabs(p);
double code(double p_m, double x) {
double tmp;
if (x <= -5.2e-46) {
tmp = p_m / -x;
} else if (x <= 1e-9) {
tmp = sqrt(0.5);
} 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 <= (-5.2d-46)) then
tmp = p_m / -x
else if (x <= 1d-9) then
tmp = sqrt(0.5d0)
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 <= -5.2e-46) {
tmp = p_m / -x;
} else if (x <= 1e-9) {
tmp = Math.sqrt(0.5);
} else {
tmp = 1.0;
}
return tmp;
}
p_m = math.fabs(p) def code(p_m, x): tmp = 0 if x <= -5.2e-46: tmp = p_m / -x elif x <= 1e-9: tmp = math.sqrt(0.5) else: tmp = 1.0 return tmp
p_m = abs(p) function code(p_m, x) tmp = 0.0 if (x <= -5.2e-46) tmp = Float64(p_m / Float64(-x)); elseif (x <= 1e-9) tmp = sqrt(0.5); else tmp = 1.0; end return tmp end
p_m = abs(p); function tmp_2 = code(p_m, x) tmp = 0.0; if (x <= -5.2e-46) tmp = p_m / -x; elseif (x <= 1e-9) tmp = sqrt(0.5); else tmp = 1.0; end tmp_2 = tmp; end
p_m = N[Abs[p], $MachinePrecision] code[p$95$m_, x_] := If[LessEqual[x, -5.2e-46], N[(p$95$m / (-x)), $MachinePrecision], If[LessEqual[x, 1e-9], N[Sqrt[0.5], $MachinePrecision], 1.0]]
\begin{array}{l}
p_m = \left|p\right|
\\
\begin{array}{l}
\mathbf{if}\;x \leq -5.2 \cdot 10^{-46}:\\
\;\;\;\;\frac{p\_m}{-x}\\
\mathbf{elif}\;x \leq 10^{-9}:\\
\;\;\;\;\sqrt{0.5}\\
\mathbf{else}:\\
\;\;\;\;1\\
\end{array}
\end{array}
if x < -5.2000000000000004e-46Initial program 45.4%
Taylor expanded in x around -inf 43.4%
associate-*r/43.4%
Simplified43.4%
Applied egg-rr47.4%
if -5.2000000000000004e-46 < x < 1.00000000000000006e-9Initial program 89.2%
Taylor expanded in x around 0 72.4%
if 1.00000000000000006e-9 < x Initial program 100.0%
expm1-log1p-u98.8%
expm1-undefine98.8%
+-commutative98.8%
add-sqr-sqrt98.8%
hypot-define98.8%
associate-*l*98.8%
sqrt-prod98.8%
metadata-eval98.8%
sqrt-unprod43.6%
add-sqr-sqrt98.8%
Applied egg-rr98.8%
sub-neg98.8%
metadata-eval98.8%
+-commutative98.8%
log1p-undefine100.0%
rem-exp-log100.0%
associate-+r+100.0%
metadata-eval100.0%
*-commutative100.0%
Simplified100.0%
associate-+r+100.0%
metadata-eval100.0%
distribute-rgt-in100.0%
metadata-eval100.0%
*-commutative100.0%
Applied egg-rr100.0%
Taylor expanded in x around inf 82.3%
metadata-eval82.3%
metadata-eval82.3%
Applied egg-rr82.3%
Final simplification68.3%
p_m = (fabs.f64 p) (FPCore (p_m x) :precision binary64 (if (<= x -1.45e-127) (/ p_m (- x)) 1.0))
p_m = fabs(p);
double code(double p_m, double x) {
double tmp;
if (x <= -1.45e-127) {
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 <= (-1.45d-127)) 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 <= -1.45e-127) {
tmp = p_m / -x;
} else {
tmp = 1.0;
}
return tmp;
}
p_m = math.fabs(p) def code(p_m, x): tmp = 0 if x <= -1.45e-127: tmp = p_m / -x else: tmp = 1.0 return tmp
p_m = abs(p) function code(p_m, x) tmp = 0.0 if (x <= -1.45e-127) 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 <= -1.45e-127) 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, -1.45e-127], N[(p$95$m / (-x)), $MachinePrecision], 1.0]
\begin{array}{l}
p_m = \left|p\right|
\\
\begin{array}{l}
\mathbf{if}\;x \leq -1.45 \cdot 10^{-127}:\\
\;\;\;\;\frac{p\_m}{-x}\\
\mathbf{else}:\\
\;\;\;\;1\\
\end{array}
\end{array}
if x < -1.45e-127Initial program 53.2%
Taylor expanded in x around -inf 32.7%
associate-*r/32.7%
Simplified32.7%
Applied egg-rr36.9%
if -1.45e-127 < x Initial program 99.7%
expm1-log1p-u98.9%
expm1-undefine98.9%
+-commutative98.9%
add-sqr-sqrt98.9%
hypot-define98.9%
associate-*l*98.9%
sqrt-prod98.9%
metadata-eval98.9%
sqrt-unprod50.6%
add-sqr-sqrt98.9%
Applied egg-rr98.9%
sub-neg98.9%
metadata-eval98.9%
+-commutative98.9%
log1p-undefine99.7%
rem-exp-log99.7%
associate-+r+99.7%
metadata-eval99.7%
*-commutative99.7%
Simplified99.7%
associate-+r+99.7%
metadata-eval99.7%
distribute-rgt-in99.7%
metadata-eval99.7%
*-commutative99.7%
Applied egg-rr99.7%
Taylor expanded in x around inf 60.5%
metadata-eval60.5%
metadata-eval60.5%
Applied egg-rr60.5%
Final simplification50.6%
p_m = (fabs.f64 p) (FPCore (p_m x) :precision binary64 (if (<= x -2.35e+36) 0.0 1.0))
p_m = fabs(p);
double code(double p_m, double x) {
double tmp;
if (x <= -2.35e+36) {
tmp = 0.0;
} 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 <= (-2.35d+36)) then
tmp = 0.0d0
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 <= -2.35e+36) {
tmp = 0.0;
} else {
tmp = 1.0;
}
return tmp;
}
p_m = math.fabs(p) def code(p_m, x): tmp = 0 if x <= -2.35e+36: tmp = 0.0 else: tmp = 1.0 return tmp
p_m = abs(p) function code(p_m, x) tmp = 0.0 if (x <= -2.35e+36) tmp = 0.0; else tmp = 1.0; end return tmp end
p_m = abs(p); function tmp_2 = code(p_m, x) tmp = 0.0; if (x <= -2.35e+36) tmp = 0.0; else tmp = 1.0; end tmp_2 = tmp; end
p_m = N[Abs[p], $MachinePrecision] code[p$95$m_, x_] := If[LessEqual[x, -2.35e+36], 0.0, 1.0]
\begin{array}{l}
p_m = \left|p\right|
\\
\begin{array}{l}
\mathbf{if}\;x \leq -2.35 \cdot 10^{+36}:\\
\;\;\;\;0\\
\mathbf{else}:\\
\;\;\;\;1\\
\end{array}
\end{array}
if x < -2.34999999999999994e36Initial program 51.1%
Taylor expanded in x around -inf 26.9%
metadata-eval26.9%
metadata-eval26.9%
metadata-eval26.9%
pow1/226.9%
metadata-eval26.9%
metadata-eval26.9%
Applied egg-rr26.9%
if -2.34999999999999994e36 < x Initial program 85.7%
expm1-log1p-u85.1%
expm1-undefine85.1%
+-commutative85.1%
add-sqr-sqrt85.1%
hypot-define85.1%
associate-*l*85.1%
sqrt-prod85.1%
metadata-eval85.1%
sqrt-unprod41.8%
add-sqr-sqrt85.1%
Applied egg-rr85.1%
sub-neg85.1%
metadata-eval85.1%
+-commutative85.1%
log1p-undefine85.7%
rem-exp-log85.7%
associate-+r+85.7%
metadata-eval85.7%
*-commutative85.7%
Simplified85.7%
associate-+r+85.7%
metadata-eval85.7%
distribute-rgt-in85.7%
metadata-eval85.7%
*-commutative85.7%
Applied egg-rr85.7%
Taylor expanded in x around inf 45.8%
metadata-eval45.8%
metadata-eval45.8%
Applied egg-rr45.8%
p_m = (fabs.f64 p) (FPCore (p_m x) :precision binary64 0.0)
p_m = fabs(p);
double code(double p_m, double x) {
return 0.0;
}
p_m = abs(p)
real(8) function code(p_m, x)
real(8), intent (in) :: p_m
real(8), intent (in) :: x
code = 0.0d0
end function
p_m = Math.abs(p);
public static double code(double p_m, double x) {
return 0.0;
}
p_m = math.fabs(p) def code(p_m, x): return 0.0
p_m = abs(p) function code(p_m, x) return 0.0 end
p_m = abs(p); function tmp = code(p_m, x) tmp = 0.0; end
p_m = N[Abs[p], $MachinePrecision] code[p$95$m_, x_] := 0.0
\begin{array}{l}
p_m = \left|p\right|
\\
0
\end{array}
Initial program 80.3%
Taylor expanded in x around -inf 7.0%
metadata-eval7.0%
metadata-eval7.0%
metadata-eval7.0%
pow1/27.0%
metadata-eval7.0%
metadata-eval7.0%
Applied egg-rr7.0%
(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 2024157
(FPCore (p x)
:name "Given's Rotation SVD example"
:precision binary64
:pre (and (< 1e-150 (fabs x)) (< (fabs x) 1e+150))
:alt
(! :herbie-platform default (sqrt (+ 1/2 (/ (copysign 1/2 x) (hypot 1 (/ (* 2 p) x))))))
(sqrt (* 0.5 (+ 1.0 (/ x (sqrt (+ (* (* 4.0 p) p) (* x x))))))))