
(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)))) -0.999) (/ p_m (- x)) (sqrt (fma x (/ 0.5 (hypot (* p_m 2.0) x)) 0.5))))
p_m = fabs(p);
double code(double p_m, double x) {
double tmp;
if ((x / sqrt(((p_m * (4.0 * p_m)) + (x * x)))) <= -0.999) {
tmp = p_m / -x;
} else {
tmp = sqrt(fma(x, (0.5 / hypot((p_m * 2.0), x)), 0.5));
}
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)))) <= -0.999) tmp = Float64(p_m / Float64(-x)); else tmp = sqrt(fma(x, Float64(0.5 / hypot(Float64(p_m * 2.0), x)), 0.5)); 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], -0.999], N[(p$95$m / (-x)), $MachinePrecision], N[Sqrt[N[(x * N[(0.5 / N[Sqrt[N[(p$95$m * 2.0), $MachinePrecision] ^ 2 + x ^ 2], $MachinePrecision]), $MachinePrecision] + 0.5), $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 -0.999:\\
\;\;\;\;\frac{p\_m}{-x}\\
\mathbf{else}:\\
\;\;\;\;\sqrt{\mathsf{fma}\left(x, \frac{0.5}{\mathsf{hypot}\left(p\_m \cdot 2, x\right)}, 0.5\right)}\\
\end{array}
\end{array}
if (/.f64 x (sqrt.f64 (+.f64 (*.f64 (*.f64 #s(literal 4 binary64) p) p) (*.f64 x x)))) < -0.998999999999999999Initial program 19.1%
Taylor expanded in x around -inf 50.9%
Taylor expanded in p around -inf 57.5%
mul-1-neg57.5%
distribute-neg-frac257.5%
Simplified57.5%
if -0.998999999999999999 < (/.f64 x (sqrt.f64 (+.f64 (*.f64 (*.f64 #s(literal 4 binary64) p) p) (*.f64 x x)))) Initial program 99.9%
add-sqr-sqrt99.9%
hypot-define99.9%
associate-*l*99.9%
sqrt-prod99.9%
metadata-eval99.9%
sqrt-unprod54.0%
add-sqr-sqrt99.9%
Applied egg-rr99.9%
*-un-lft-identity99.9%
distribute-rgt-in99.9%
metadata-eval99.9%
associate-*l/99.9%
Applied egg-rr99.9%
*-lft-identity99.9%
+-commutative99.9%
associate-/l*99.9%
fma-define99.9%
*-commutative99.9%
Simplified99.9%
Final simplification90.6%
p_m = (fabs.f64 p) (FPCore (p_m x) :precision binary64 (if (<= (/ x (sqrt (+ (* p_m (* 4.0 p_m)) (* x x)))) -0.999) (/ 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)))) <= -0.999) {
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)))) <= -0.999) {
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)))) <= -0.999: 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)))) <= -0.999) 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)))) <= -0.999) 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], -0.999], 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 -0.999:\\
\;\;\;\;\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)))) < -0.998999999999999999Initial program 19.1%
Taylor expanded in x around -inf 50.9%
Taylor expanded in p around -inf 57.5%
mul-1-neg57.5%
distribute-neg-frac257.5%
Simplified57.5%
if -0.998999999999999999 < (/.f64 x (sqrt.f64 (+.f64 (*.f64 (*.f64 #s(literal 4 binary64) p) p) (*.f64 x x)))) Initial program 99.9%
add-sqr-sqrt99.9%
hypot-define99.9%
associate-*l*99.9%
sqrt-prod99.9%
metadata-eval99.9%
sqrt-unprod54.0%
add-sqr-sqrt99.9%
Applied egg-rr99.9%
Final simplification90.6%
p_m = (fabs.f64 p) (FPCore (p_m x) :precision binary64 (if (<= p_m 8.2e-72) 1.0 (sqrt 0.5)))
p_m = fabs(p);
double code(double p_m, double x) {
double tmp;
if (p_m <= 8.2e-72) {
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 <= 8.2d-72) 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 <= 8.2e-72) {
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 <= 8.2e-72: 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 <= 8.2e-72) 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 <= 8.2e-72) 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, 8.2e-72], 1.0, N[Sqrt[0.5], $MachinePrecision]]
\begin{array}{l}
p_m = \left|p\right|
\\
\begin{array}{l}
\mathbf{if}\;p\_m \leq 8.2 \cdot 10^{-72}:\\
\;\;\;\;1\\
\mathbf{else}:\\
\;\;\;\;\sqrt{0.5}\\
\end{array}
\end{array}
if p < 8.20000000000000007e-72Initial program 77.7%
add-sqr-sqrt77.7%
hypot-define77.7%
associate-*l*77.7%
sqrt-prod77.7%
metadata-eval77.7%
sqrt-unprod22.7%
add-sqr-sqrt77.7%
Applied egg-rr77.7%
*-un-lft-identity77.7%
distribute-rgt-in77.7%
metadata-eval77.7%
associate-*l/77.7%
Applied egg-rr77.7%
*-lft-identity77.7%
+-commutative77.7%
associate-/l*76.3%
fma-define72.6%
*-commutative72.6%
Simplified72.6%
add-log-exp72.5%
Applied egg-rr72.5%
Taylor expanded in x around inf 41.5%
if 8.20000000000000007e-72 < p Initial program 91.8%
Taylor expanded in x around 0 83.6%
p_m = (fabs.f64 p) (FPCore (p_m x) :precision binary64 (if (<= x -2.7e-146) (/ p_m (- x)) 1.0))
p_m = fabs(p);
double code(double p_m, double x) {
double tmp;
if (x <= -2.7e-146) {
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 <= (-2.7d-146)) 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 <= -2.7e-146) {
tmp = p_m / -x;
} else {
tmp = 1.0;
}
return tmp;
}
p_m = math.fabs(p) def code(p_m, x): tmp = 0 if x <= -2.7e-146: tmp = p_m / -x else: tmp = 1.0 return tmp
p_m = abs(p) function code(p_m, x) tmp = 0.0 if (x <= -2.7e-146) 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 <= -2.7e-146) 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, -2.7e-146], N[(p$95$m / (-x)), $MachinePrecision], 1.0]
\begin{array}{l}
p_m = \left|p\right|
\\
\begin{array}{l}
\mathbf{if}\;x \leq -2.7 \cdot 10^{-146}:\\
\;\;\;\;\frac{p\_m}{-x}\\
\mathbf{else}:\\
\;\;\;\;1\\
\end{array}
\end{array}
if x < -2.69999999999999995e-146Initial program 64.5%
Taylor expanded in x around -inf 25.7%
Taylor expanded in p around -inf 27.1%
mul-1-neg27.1%
distribute-neg-frac227.1%
Simplified27.1%
if -2.69999999999999995e-146 < x Initial program 100.0%
add-sqr-sqrt100.0%
hypot-define100.0%
associate-*l*100.0%
sqrt-prod100.0%
metadata-eval100.0%
sqrt-unprod57.0%
add-sqr-sqrt100.0%
Applied egg-rr100.0%
*-un-lft-identity100.0%
distribute-rgt-in100.0%
metadata-eval100.0%
associate-*l/100.0%
Applied egg-rr100.0%
*-lft-identity100.0%
+-commutative100.0%
associate-/l*100.0%
fma-define100.0%
*-commutative100.0%
Simplified100.0%
add-log-exp100.0%
Applied egg-rr100.0%
Taylor expanded in x around inf 59.7%
p_m = (fabs.f64 p) (FPCore (p_m x) :precision binary64 (if (<= x -3.8e+124) (/ p_m x) 1.0))
p_m = fabs(p);
double code(double p_m, double x) {
double tmp;
if (x <= -3.8e+124) {
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+124)) 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+124) {
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+124: 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+124) tmp = Float64(p_m / 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+124) 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+124], 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^{+124}:\\
\;\;\;\;\frac{p\_m}{x}\\
\mathbf{else}:\\
\;\;\;\;1\\
\end{array}
\end{array}
if x < -3.7999999999999998e124Initial program 70.7%
Taylor expanded in x around -inf 53.9%
Taylor expanded in p around 0 53.3%
if -3.7999999999999998e124 < x Initial program 83.1%
add-sqr-sqrt83.1%
hypot-define83.1%
associate-*l*83.1%
sqrt-prod83.1%
metadata-eval83.1%
sqrt-unprod45.1%
add-sqr-sqrt83.1%
Applied egg-rr83.1%
*-un-lft-identity83.1%
distribute-rgt-in83.1%
metadata-eval83.1%
associate-*l/83.1%
Applied egg-rr83.1%
*-lft-identity83.1%
+-commutative83.1%
associate-/l*82.7%
fma-define81.8%
*-commutative81.8%
Simplified81.8%
add-log-exp81.8%
Applied egg-rr81.8%
Taylor expanded in x around inf 38.5%
p_m = (fabs.f64 p) (FPCore (p_m x) :precision binary64 1.0)
p_m = fabs(p);
double code(double p_m, double x) {
return 1.0;
}
p_m = abs(p)
real(8) function code(p_m, x)
real(8), intent (in) :: p_m
real(8), intent (in) :: x
code = 1.0d0
end function
p_m = Math.abs(p);
public static double code(double p_m, double x) {
return 1.0;
}
p_m = math.fabs(p) def code(p_m, x): return 1.0
p_m = abs(p) function code(p_m, x) return 1.0 end
p_m = abs(p); function tmp = code(p_m, x) tmp = 1.0; end
p_m = N[Abs[p], $MachinePrecision] code[p$95$m_, x_] := 1.0
\begin{array}{l}
p_m = \left|p\right|
\\
1
\end{array}
Initial program 82.2%
add-sqr-sqrt82.2%
hypot-define82.2%
associate-*l*82.2%
sqrt-prod82.2%
metadata-eval82.2%
sqrt-unprod44.8%
add-sqr-sqrt82.2%
Applied egg-rr82.2%
*-un-lft-identity82.2%
distribute-rgt-in82.2%
metadata-eval82.2%
associate-*l/82.2%
Applied egg-rr82.2%
*-lft-identity82.2%
+-commutative82.2%
associate-/l*81.2%
fma-define78.8%
*-commutative78.8%
Simplified78.8%
add-log-exp78.8%
Applied egg-rr78.8%
Taylor expanded in x around inf 36.6%
(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 2024087
(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))))))))