
(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}
NOTE: p should be positive before calling this function (FPCore (p x) :precision binary64 (if (<= (/ x (sqrt (+ (* p (* 4.0 p)) (* x x)))) -0.9999) (/ (- p) x) (sqrt (* 0.5 (+ 1.0 (/ x (hypot (* p 2.0) x)))))))
p = abs(p);
double code(double p, double x) {
double tmp;
if ((x / sqrt(((p * (4.0 * p)) + (x * x)))) <= -0.9999) {
tmp = -p / x;
} else {
tmp = sqrt((0.5 * (1.0 + (x / hypot((p * 2.0), x)))));
}
return tmp;
}
p = Math.abs(p);
public static double code(double p, double x) {
double tmp;
if ((x / Math.sqrt(((p * (4.0 * p)) + (x * x)))) <= -0.9999) {
tmp = -p / x;
} else {
tmp = Math.sqrt((0.5 * (1.0 + (x / Math.hypot((p * 2.0), x)))));
}
return tmp;
}
p = abs(p) def code(p, x): tmp = 0 if (x / math.sqrt(((p * (4.0 * p)) + (x * x)))) <= -0.9999: tmp = -p / x else: tmp = math.sqrt((0.5 * (1.0 + (x / math.hypot((p * 2.0), x))))) return tmp
p = abs(p) function code(p, x) tmp = 0.0 if (Float64(x / sqrt(Float64(Float64(p * Float64(4.0 * p)) + Float64(x * x)))) <= -0.9999) tmp = Float64(Float64(-p) / x); else tmp = sqrt(Float64(0.5 * Float64(1.0 + Float64(x / hypot(Float64(p * 2.0), x))))); end return tmp end
p = abs(p) function tmp_2 = code(p, x) tmp = 0.0; if ((x / sqrt(((p * (4.0 * p)) + (x * x)))) <= -0.9999) tmp = -p / x; else tmp = sqrt((0.5 * (1.0 + (x / hypot((p * 2.0), x))))); end tmp_2 = tmp; end
NOTE: p should be positive before calling this function code[p_, x_] := If[LessEqual[N[(x / N[Sqrt[N[(N[(p * N[(4.0 * p), $MachinePrecision]), $MachinePrecision] + N[(x * x), $MachinePrecision]), $MachinePrecision]], $MachinePrecision]), $MachinePrecision], -0.9999], N[((-p) / x), $MachinePrecision], N[Sqrt[N[(0.5 * N[(1.0 + N[(x / N[Sqrt[N[(p * 2.0), $MachinePrecision] ^ 2 + x ^ 2], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]], $MachinePrecision]]
\begin{array}{l}
p = |p|\\
\\
\begin{array}{l}
\mathbf{if}\;\frac{x}{\sqrt{p \cdot \left(4 \cdot p\right) + x \cdot x}} \leq -0.9999:\\
\;\;\;\;\frac{-p}{x}\\
\mathbf{else}:\\
\;\;\;\;\sqrt{0.5 \cdot \left(1 + \frac{x}{\mathsf{hypot}\left(p \cdot 2, x\right)}\right)}\\
\end{array}
\end{array}
if (/.f64 x (sqrt.f64 (+.f64 (*.f64 (*.f64 4 p) p) (*.f64 x x)))) < -0.99990000000000001Initial program 15.4%
add-sqr-sqrt15.4%
hypot-def15.4%
associate-*l*15.4%
sqrt-prod15.4%
metadata-eval15.4%
sqrt-unprod10.8%
add-sqr-sqrt15.4%
Applied egg-rr15.4%
add-cbrt-cube15.4%
pow1/315.4%
add-sqr-sqrt15.4%
pow115.4%
pow1/215.4%
pow-prod-up15.4%
distribute-lft-in15.4%
metadata-eval15.4%
metadata-eval15.4%
Applied egg-rr15.4%
unpow1/315.4%
*-commutative15.4%
Simplified15.4%
Taylor expanded in x around -inf 62.6%
mul-1-neg62.6%
distribute-neg-frac62.6%
Simplified62.6%
if -0.99990000000000001 < (/.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-unprod42.6%
add-sqr-sqrt99.9%
Applied egg-rr99.9%
Final simplification92.4%
NOTE: p should be positive before calling this function (FPCore (p x) :precision binary64 (if (<= p 1.6e-41) (/ (- p) x) (sqrt 0.5)))
p = abs(p);
double code(double p, double x) {
double tmp;
if (p <= 1.6e-41) {
tmp = -p / x;
} else {
tmp = sqrt(0.5);
}
return tmp;
}
NOTE: p should be positive before calling this function
real(8) function code(p, x)
real(8), intent (in) :: p
real(8), intent (in) :: x
real(8) :: tmp
if (p <= 1.6d-41) then
tmp = -p / x
else
tmp = sqrt(0.5d0)
end if
code = tmp
end function
p = Math.abs(p);
public static double code(double p, double x) {
double tmp;
if (p <= 1.6e-41) {
tmp = -p / x;
} else {
tmp = Math.sqrt(0.5);
}
return tmp;
}
p = abs(p) def code(p, x): tmp = 0 if p <= 1.6e-41: tmp = -p / x else: tmp = math.sqrt(0.5) return tmp
p = abs(p) function code(p, x) tmp = 0.0 if (p <= 1.6e-41) tmp = Float64(Float64(-p) / x); else tmp = sqrt(0.5); end return tmp end
p = abs(p) function tmp_2 = code(p, x) tmp = 0.0; if (p <= 1.6e-41) tmp = -p / x; else tmp = sqrt(0.5); end tmp_2 = tmp; end
NOTE: p should be positive before calling this function code[p_, x_] := If[LessEqual[p, 1.6e-41], N[((-p) / x), $MachinePrecision], N[Sqrt[0.5], $MachinePrecision]]
\begin{array}{l}
p = |p|\\
\\
\begin{array}{l}
\mathbf{if}\;p \leq 1.6 \cdot 10^{-41}:\\
\;\;\;\;\frac{-p}{x}\\
\mathbf{else}:\\
\;\;\;\;\sqrt{0.5}\\
\end{array}
\end{array}
if p < 1.60000000000000006e-41Initial program 79.8%
add-sqr-sqrt79.8%
hypot-def79.8%
associate-*l*79.8%
sqrt-prod79.8%
metadata-eval79.8%
sqrt-unprod17.7%
add-sqr-sqrt79.8%
Applied egg-rr79.8%
add-cbrt-cube79.8%
pow1/379.8%
add-sqr-sqrt79.8%
pow179.8%
pow1/279.8%
pow-prod-up79.8%
distribute-lft-in79.8%
metadata-eval79.8%
metadata-eval79.8%
Applied egg-rr79.8%
unpow1/379.8%
*-commutative79.8%
Simplified79.8%
Taylor expanded in x around -inf 16.7%
mul-1-neg16.7%
distribute-neg-frac16.7%
Simplified16.7%
if 1.60000000000000006e-41 < p Initial program 91.6%
Taylor expanded in x around 0 79.4%
Final simplification32.4%
NOTE: p should be positive before calling this function (FPCore (p x) :precision binary64 (if (<= p 1.95e-31) 1.0 (sqrt 0.5)))
p = abs(p);
double code(double p, double x) {
double tmp;
if (p <= 1.95e-31) {
tmp = 1.0;
} else {
tmp = sqrt(0.5);
}
return tmp;
}
NOTE: p should be positive before calling this function
real(8) function code(p, x)
real(8), intent (in) :: p
real(8), intent (in) :: x
real(8) :: tmp
if (p <= 1.95d-31) then
tmp = 1.0d0
else
tmp = sqrt(0.5d0)
end if
code = tmp
end function
p = Math.abs(p);
public static double code(double p, double x) {
double tmp;
if (p <= 1.95e-31) {
tmp = 1.0;
} else {
tmp = Math.sqrt(0.5);
}
return tmp;
}
p = abs(p) def code(p, x): tmp = 0 if p <= 1.95e-31: tmp = 1.0 else: tmp = math.sqrt(0.5) return tmp
p = abs(p) function code(p, x) tmp = 0.0 if (p <= 1.95e-31) tmp = 1.0; else tmp = sqrt(0.5); end return tmp end
p = abs(p) function tmp_2 = code(p, x) tmp = 0.0; if (p <= 1.95e-31) tmp = 1.0; else tmp = sqrt(0.5); end tmp_2 = tmp; end
NOTE: p should be positive before calling this function code[p_, x_] := If[LessEqual[p, 1.95e-31], 1.0, N[Sqrt[0.5], $MachinePrecision]]
\begin{array}{l}
p = |p|\\
\\
\begin{array}{l}
\mathbf{if}\;p \leq 1.95 \cdot 10^{-31}:\\
\;\;\;\;1\\
\mathbf{else}:\\
\;\;\;\;\sqrt{0.5}\\
\end{array}
\end{array}
if p < 1.9500000000000001e-31Initial program 79.9%
Taylor expanded in x around inf 45.8%
if 1.9500000000000001e-31 < p Initial program 91.4%
Taylor expanded in x around 0 80.3%
Final simplification54.3%
NOTE: p should be positive before calling this function (FPCore (p x) :precision binary64 (if (<= x -5e-310) (/ (- p) x) (/ p x)))
p = abs(p);
double code(double p, double x) {
double tmp;
if (x <= -5e-310) {
tmp = -p / x;
} else {
tmp = p / x;
}
return tmp;
}
NOTE: p should be positive before calling this function
real(8) function code(p, x)
real(8), intent (in) :: p
real(8), intent (in) :: x
real(8) :: tmp
if (x <= (-5d-310)) then
tmp = -p / x
else
tmp = p / x
end if
code = tmp
end function
p = Math.abs(p);
public static double code(double p, double x) {
double tmp;
if (x <= -5e-310) {
tmp = -p / x;
} else {
tmp = p / x;
}
return tmp;
}
p = abs(p) def code(p, x): tmp = 0 if x <= -5e-310: tmp = -p / x else: tmp = p / x return tmp
p = abs(p) function code(p, x) tmp = 0.0 if (x <= -5e-310) tmp = Float64(Float64(-p) / x); else tmp = Float64(p / x); end return tmp end
p = abs(p) function tmp_2 = code(p, x) tmp = 0.0; if (x <= -5e-310) tmp = -p / x; else tmp = p / x; end tmp_2 = tmp; end
NOTE: p should be positive before calling this function code[p_, x_] := If[LessEqual[x, -5e-310], N[((-p) / x), $MachinePrecision], N[(p / x), $MachinePrecision]]
\begin{array}{l}
p = |p|\\
\\
\begin{array}{l}
\mathbf{if}\;x \leq -5 \cdot 10^{-310}:\\
\;\;\;\;\frac{-p}{x}\\
\mathbf{else}:\\
\;\;\;\;\frac{p}{x}\\
\end{array}
\end{array}
if x < -4.999999999999985e-310Initial program 64.2%
add-sqr-sqrt64.2%
hypot-def64.2%
associate-*l*64.2%
sqrt-prod64.2%
metadata-eval64.2%
sqrt-unprod26.5%
add-sqr-sqrt64.2%
Applied egg-rr64.2%
add-cbrt-cube64.1%
pow1/364.2%
add-sqr-sqrt64.2%
pow164.2%
pow1/264.2%
pow-prod-up64.2%
distribute-lft-in64.2%
metadata-eval64.2%
metadata-eval64.2%
Applied egg-rr64.2%
unpow1/364.1%
*-commutative64.1%
Simplified64.1%
Taylor expanded in x around -inf 28.2%
mul-1-neg28.2%
distribute-neg-frac28.2%
Simplified28.2%
if -4.999999999999985e-310 < x Initial program 100.0%
add-sqr-sqrt100.0%
hypot-def100.0%
associate-*l*100.0%
sqrt-prod100.0%
metadata-eval100.0%
sqrt-unprod45.1%
add-sqr-sqrt100.0%
Applied egg-rr100.0%
add-cbrt-cube100.0%
pow1/3100.0%
add-sqr-sqrt100.0%
pow1100.0%
pow1/2100.0%
pow-prod-up100.0%
distribute-lft-in100.0%
metadata-eval100.0%
metadata-eval100.0%
Applied egg-rr100.0%
unpow1/3100.0%
*-commutative100.0%
Simplified100.0%
Taylor expanded in x around -inf 4.4%
unpow24.4%
associate-*r/4.6%
unpow24.6%
associate-/r*4.6%
Simplified4.6%
Taylor expanded in p around 0 3.3%
Final simplification15.3%
NOTE: p should be positive before calling this function (FPCore (p x) :precision binary64 (/ p x))
p = abs(p);
double code(double p, double x) {
return p / x;
}
NOTE: p should be positive before calling this function
real(8) function code(p, x)
real(8), intent (in) :: p
real(8), intent (in) :: x
code = p / x
end function
p = Math.abs(p);
public static double code(double p, double x) {
return p / x;
}
p = abs(p) def code(p, x): return p / x
p = abs(p) function code(p, x) return Float64(p / x) end
p = abs(p) function tmp = code(p, x) tmp = p / x; end
NOTE: p should be positive before calling this function code[p_, x_] := N[(p / x), $MachinePrecision]
\begin{array}{l}
p = |p|\\
\\
\frac{p}{x}
\end{array}
Initial program 82.8%
add-sqr-sqrt82.8%
hypot-def82.8%
associate-*l*82.8%
sqrt-prod82.8%
metadata-eval82.8%
sqrt-unprod36.2%
add-sqr-sqrt82.8%
Applied egg-rr82.8%
add-cbrt-cube82.8%
pow1/382.8%
add-sqr-sqrt82.8%
pow182.8%
pow1/282.8%
pow-prod-up82.8%
distribute-lft-in82.8%
metadata-eval82.8%
metadata-eval82.8%
Applied egg-rr82.8%
unpow1/382.7%
*-commutative82.7%
Simplified82.7%
Taylor expanded in x around -inf 12.4%
unpow212.4%
associate-*r/14.0%
unpow214.0%
associate-/r*14.0%
Simplified14.0%
Taylor expanded in p around 0 12.8%
Final simplification12.8%
(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 2023240
(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))))))))