
(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) (sqrt (* 0.5 (exp (log1p (/ 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)))) <= -1.0) {
tmp = -p_m / x;
} else {
tmp = sqrt((0.5 * exp(log1p((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)))) <= -1.0) {
tmp = -p_m / x;
} else {
tmp = Math.sqrt((0.5 * Math.exp(Math.log1p((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)))) <= -1.0: tmp = -p_m / x else: tmp = math.sqrt((0.5 * math.exp(math.log1p((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)))) <= -1.0) tmp = Float64(Float64(-p_m) / x); else tmp = sqrt(Float64(0.5 * exp(log1p(Float64(x / hypot(x, Float64(p_m * 2.0))))))); 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[Sqrt[N[(0.5 * N[Exp[N[Log[1 + 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 -1:\\
\;\;\;\;\frac{-p_m}{x}\\
\mathbf{else}:\\
\;\;\;\;\sqrt{0.5 \cdot e^{\mathsf{log1p}\left(\frac{x}{\mathsf{hypot}\left(x, p_m \cdot 2\right)}\right)}}\\
\end{array}
\end{array}
if (/.f64 x (sqrt.f64 (+.f64 (*.f64 (*.f64 4 p) p) (*.f64 x x)))) < -1Initial program 13.9%
add-sqr-sqrt13.9%
hypot-def13.9%
associate-*l*13.9%
sqrt-prod13.9%
metadata-eval13.9%
sqrt-unprod8.3%
add-sqr-sqrt13.9%
Applied egg-rr13.9%
Taylor expanded in x around -inf 54.0%
mul-1-neg54.0%
associate-*r*54.1%
Simplified54.1%
associate-*l*54.0%
sqrt-unprod54.8%
metadata-eval54.8%
metadata-eval54.8%
*-rgt-identity54.8%
expm1-log1p-u54.4%
expm1-udef18.3%
Applied egg-rr18.3%
expm1-def54.4%
expm1-log1p54.8%
Simplified54.8%
if -1 < (/.f64 x (sqrt.f64 (+.f64 (*.f64 (*.f64 4 p) p) (*.f64 x x)))) Initial program 99.9%
flip3-+99.9%
add-exp-log99.9%
flip3-+99.9%
log1p-udef99.9%
div-inv99.9%
div-inv99.9%
Applied egg-rr99.9%
Final simplification90.7%
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(Float64(-p_m) / 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 4 p) p) (*.f64 x x)))) < -1Initial program 13.9%
add-sqr-sqrt13.9%
hypot-def13.9%
associate-*l*13.9%
sqrt-prod13.9%
metadata-eval13.9%
sqrt-unprod8.3%
add-sqr-sqrt13.9%
Applied egg-rr13.9%
Taylor expanded in x around -inf 54.0%
mul-1-neg54.0%
associate-*r*54.1%
Simplified54.1%
associate-*l*54.0%
sqrt-unprod54.8%
metadata-eval54.8%
metadata-eval54.8%
*-rgt-identity54.8%
expm1-log1p-u54.4%
expm1-udef18.3%
Applied egg-rr18.3%
expm1-def54.4%
expm1-log1p54.8%
Simplified54.8%
if -1 < (/.f64 x (sqrt.f64 (+.f64 (*.f64 (*.f64 4 p) p) (*.f64 x x)))) Initial program 99.9%
add-sqr-sqrt99.9%
hypot-def99.9%
associate-*l*99.9%
sqrt-prod99.9%
metadata-eval99.9%
sqrt-unprod49.9%
add-sqr-sqrt99.9%
Applied egg-rr99.9%
Final simplification90.7%
p_m = (fabs.f64 p) (FPCore (p_m x) :precision binary64 (if (<= p_m 1.7e-247) 1.0 (if (<= p_m 3.5e-175) (/ (- p_m) x) (if (<= p_m 4.4e-103) 1.0 (sqrt 0.5)))))
p_m = fabs(p);
double code(double p_m, double x) {
double tmp;
if (p_m <= 1.7e-247) {
tmp = 1.0;
} else if (p_m <= 3.5e-175) {
tmp = -p_m / x;
} else if (p_m <= 4.4e-103) {
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 <= 1.7d-247) then
tmp = 1.0d0
else if (p_m <= 3.5d-175) then
tmp = -p_m / x
else if (p_m <= 4.4d-103) 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 <= 1.7e-247) {
tmp = 1.0;
} else if (p_m <= 3.5e-175) {
tmp = -p_m / x;
} else if (p_m <= 4.4e-103) {
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 <= 1.7e-247: tmp = 1.0 elif p_m <= 3.5e-175: tmp = -p_m / x elif p_m <= 4.4e-103: 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 <= 1.7e-247) tmp = 1.0; elseif (p_m <= 3.5e-175) tmp = Float64(Float64(-p_m) / x); elseif (p_m <= 4.4e-103) 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 <= 1.7e-247) tmp = 1.0; elseif (p_m <= 3.5e-175) tmp = -p_m / x; elseif (p_m <= 4.4e-103) 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, 1.7e-247], 1.0, If[LessEqual[p$95$m, 3.5e-175], N[((-p$95$m) / x), $MachinePrecision], If[LessEqual[p$95$m, 4.4e-103], 1.0, N[Sqrt[0.5], $MachinePrecision]]]]
\begin{array}{l}
p_m = \left|p\right|
\\
\begin{array}{l}
\mathbf{if}\;p_m \leq 1.7 \cdot 10^{-247}:\\
\;\;\;\;1\\
\mathbf{elif}\;p_m \leq 3.5 \cdot 10^{-175}:\\
\;\;\;\;\frac{-p_m}{x}\\
\mathbf{elif}\;p_m \leq 4.4 \cdot 10^{-103}:\\
\;\;\;\;1\\
\mathbf{else}:\\
\;\;\;\;\sqrt{0.5}\\
\end{array}
\end{array}
if p < 1.7000000000000001e-247 or 3.49999999999999999e-175 < p < 4.3999999999999999e-103Initial program 82.1%
expm1-log1p-u81.4%
expm1-udef81.4%
Applied egg-rr81.4%
Taylor expanded in x around inf 41.1%
if 1.7000000000000001e-247 < p < 3.49999999999999999e-175Initial program 29.4%
add-sqr-sqrt29.4%
hypot-def29.4%
associate-*l*29.4%
sqrt-prod29.4%
metadata-eval29.4%
sqrt-unprod29.4%
add-sqr-sqrt29.4%
Applied egg-rr29.4%
Taylor expanded in x around -inf 76.1%
mul-1-neg76.1%
associate-*r*76.1%
Simplified76.1%
associate-*l*76.1%
sqrt-unprod77.5%
metadata-eval77.5%
metadata-eval77.5%
*-rgt-identity77.5%
expm1-log1p-u77.5%
expm1-udef7.1%
Applied egg-rr7.1%
expm1-def77.5%
expm1-log1p77.5%
Simplified77.5%
if 4.3999999999999999e-103 < p Initial program 90.9%
Taylor expanded in x around 0 77.1%
Final simplification55.2%
p_m = (fabs.f64 p) (FPCore (p_m x) :precision binary64 (if (<= x -2.8e-134) (/ (- p_m) x) 1.0))
p_m = fabs(p);
double code(double p_m, double x) {
double tmp;
if (x <= -2.8e-134) {
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 <= (-2.8d-134)) 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 <= -2.8e-134) {
tmp = -p_m / x;
} else {
tmp = 1.0;
}
return tmp;
}
p_m = math.fabs(p) def code(p_m, x): tmp = 0 if x <= -2.8e-134: tmp = -p_m / x else: tmp = 1.0 return tmp
p_m = abs(p) function code(p_m, x) tmp = 0.0 if (x <= -2.8e-134) tmp = Float64(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 <= -2.8e-134) 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, -2.8e-134], N[((-p$95$m) / x), $MachinePrecision], 1.0]
\begin{array}{l}
p_m = \left|p\right|
\\
\begin{array}{l}
\mathbf{if}\;x \leq -2.8 \cdot 10^{-134}:\\
\;\;\;\;\frac{-p_m}{x}\\
\mathbf{else}:\\
\;\;\;\;1\\
\end{array}
\end{array}
if x < -2.7999999999999999e-134Initial program 57.2%
add-sqr-sqrt57.2%
hypot-def57.2%
associate-*l*57.2%
sqrt-prod57.2%
metadata-eval57.2%
sqrt-unprod30.2%
add-sqr-sqrt57.2%
Applied egg-rr57.2%
Taylor expanded in x around -inf 29.5%
mul-1-neg29.5%
associate-*r*29.5%
Simplified29.5%
associate-*l*29.5%
sqrt-unprod29.9%
metadata-eval29.9%
metadata-eval29.9%
*-rgt-identity29.9%
expm1-log1p-u29.5%
expm1-udef11.2%
Applied egg-rr11.2%
expm1-def29.5%
expm1-log1p29.9%
Simplified29.9%
if -2.7999999999999999e-134 < x Initial program 99.4%
expm1-log1p-u98.5%
expm1-udef98.5%
Applied egg-rr98.5%
Taylor expanded in x around inf 52.2%
Final simplification43.2%
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 82.4%
expm1-log1p-u81.6%
expm1-udef81.6%
Applied egg-rr81.6%
Taylor expanded in x around inf 36.3%
Final simplification36.3%
(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 2023339
(FPCore (p x)
:name "Given's Rotation SVD example"
:precision binary64
:pre (and (< 1e-150 (fabs x)) (< (fabs x) 1e+150))
:herbie-target
(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))))))))