
(FPCore (x) :precision binary64 (log (/ (sinh x) x)))
double code(double x) {
return log((sinh(x) / x));
}
real(8) function code(x)
real(8), intent (in) :: x
code = log((sinh(x) / x))
end function
public static double code(double x) {
return Math.log((Math.sinh(x) / x));
}
def code(x): return math.log((math.sinh(x) / x))
function code(x) return log(Float64(sinh(x) / x)) end
function tmp = code(x) tmp = log((sinh(x) / x)); end
code[x_] := N[Log[N[(N[Sinh[x], $MachinePrecision] / x), $MachinePrecision]], $MachinePrecision]
\begin{array}{l}
\\
\log \left(\frac{\sinh x}{x}\right)
\end{array}
Sampling outcomes in binary64 precision:
Herbie found 2 alternatives:
| Alternative | Accuracy | Speedup |
|---|
(FPCore (x) :precision binary64 (log (/ (sinh x) x)))
double code(double x) {
return log((sinh(x) / x));
}
real(8) function code(x)
real(8), intent (in) :: x
code = log((sinh(x) / x))
end function
public static double code(double x) {
return Math.log((Math.sinh(x) / x));
}
def code(x): return math.log((math.sinh(x) / x))
function code(x) return log(Float64(sinh(x) / x)) end
function tmp = code(x) tmp = log((sinh(x) / x)); end
code[x_] := N[Log[N[(N[Sinh[x], $MachinePrecision] / x), $MachinePrecision]], $MachinePrecision]
\begin{array}{l}
\\
\log \left(\frac{\sinh x}{x}\right)
\end{array}
(FPCore (x)
:precision binary64
(*
x
(*
x
(+
0.16666666666666666
(*
(pow x 2.0)
(-
(*
(pow x 2.0)
(+ 0.0003527336860670194 (* (pow x 2.0) -2.6455026455026456e-5)))
0.005555555555555556))))))
double code(double x) {
return x * (x * (0.16666666666666666 + (pow(x, 2.0) * ((pow(x, 2.0) * (0.0003527336860670194 + (pow(x, 2.0) * -2.6455026455026456e-5))) - 0.005555555555555556))));
}
real(8) function code(x)
real(8), intent (in) :: x
code = x * (x * (0.16666666666666666d0 + ((x ** 2.0d0) * (((x ** 2.0d0) * (0.0003527336860670194d0 + ((x ** 2.0d0) * (-2.6455026455026456d-5)))) - 0.005555555555555556d0))))
end function
public static double code(double x) {
return x * (x * (0.16666666666666666 + (Math.pow(x, 2.0) * ((Math.pow(x, 2.0) * (0.0003527336860670194 + (Math.pow(x, 2.0) * -2.6455026455026456e-5))) - 0.005555555555555556))));
}
def code(x): return x * (x * (0.16666666666666666 + (math.pow(x, 2.0) * ((math.pow(x, 2.0) * (0.0003527336860670194 + (math.pow(x, 2.0) * -2.6455026455026456e-5))) - 0.005555555555555556))))
function code(x) return Float64(x * Float64(x * Float64(0.16666666666666666 + Float64((x ^ 2.0) * Float64(Float64((x ^ 2.0) * Float64(0.0003527336860670194 + Float64((x ^ 2.0) * -2.6455026455026456e-5))) - 0.005555555555555556))))) end
function tmp = code(x) tmp = x * (x * (0.16666666666666666 + ((x ^ 2.0) * (((x ^ 2.0) * (0.0003527336860670194 + ((x ^ 2.0) * -2.6455026455026456e-5))) - 0.005555555555555556)))); end
code[x_] := N[(x * N[(x * N[(0.16666666666666666 + N[(N[Power[x, 2.0], $MachinePrecision] * N[(N[(N[Power[x, 2.0], $MachinePrecision] * N[(0.0003527336860670194 + N[(N[Power[x, 2.0], $MachinePrecision] * -2.6455026455026456e-5), $MachinePrecision]), $MachinePrecision]), $MachinePrecision] - 0.005555555555555556), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
x \cdot \left(x \cdot \left(0.16666666666666666 + {x}^{2} \cdot \left({x}^{2} \cdot \left(0.0003527336860670194 + {x}^{2} \cdot -2.6455026455026456 \cdot 10^{-5}\right) - 0.005555555555555556\right)\right)\right)
\end{array}
Initial program 53.3%
Taylor expanded in x around 0 96.7%
add-sqr-sqrt96.4%
pow296.4%
Applied egg-rr96.4%
unpow296.4%
*-commutative96.4%
*-commutative96.4%
swap-sqr96.6%
add-sqr-sqrt96.7%
fma-undefine96.7%
log1p-expm1-u96.6%
log1p-define96.6%
+-commutative96.6%
associate-*r*96.7%
Applied egg-rr96.7%
Taylor expanded in x around 0 96.7%
Final simplification96.7%
(FPCore (x) :precision binary64 (* x (* x 0.16666666666666666)))
double code(double x) {
return x * (x * 0.16666666666666666);
}
real(8) function code(x)
real(8), intent (in) :: x
code = x * (x * 0.16666666666666666d0)
end function
public static double code(double x) {
return x * (x * 0.16666666666666666);
}
def code(x): return x * (x * 0.16666666666666666)
function code(x) return Float64(x * Float64(x * 0.16666666666666666)) end
function tmp = code(x) tmp = x * (x * 0.16666666666666666); end
code[x_] := N[(x * N[(x * 0.16666666666666666), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
x \cdot \left(x \cdot 0.16666666666666666\right)
\end{array}
Initial program 53.3%
Taylor expanded in x around 0 96.7%
add-sqr-sqrt96.4%
pow296.4%
Applied egg-rr96.4%
unpow296.4%
*-commutative96.4%
*-commutative96.4%
swap-sqr96.6%
add-sqr-sqrt96.7%
fma-undefine96.7%
log1p-expm1-u96.6%
log1p-define96.6%
+-commutative96.6%
associate-*r*96.7%
Applied egg-rr96.7%
Taylor expanded in x around 0 96.6%
Final simplification96.6%
(FPCore (x)
:precision binary64
(if (< (fabs x) 0.085)
(*
(* x x)
(fma
(fma
(fma -2.6455026455026456e-5 (* x x) 0.0003527336860670194)
(* x x)
-0.005555555555555556)
(* x x)
0.16666666666666666))
(log (/ (sinh x) x))))
double code(double x) {
double tmp;
if (fabs(x) < 0.085) {
tmp = (x * x) * fma(fma(fma(-2.6455026455026456e-5, (x * x), 0.0003527336860670194), (x * x), -0.005555555555555556), (x * x), 0.16666666666666666);
} else {
tmp = log((sinh(x) / x));
}
return tmp;
}
function code(x) tmp = 0.0 if (abs(x) < 0.085) tmp = Float64(Float64(x * x) * fma(fma(fma(-2.6455026455026456e-5, Float64(x * x), 0.0003527336860670194), Float64(x * x), -0.005555555555555556), Float64(x * x), 0.16666666666666666)); else tmp = log(Float64(sinh(x) / x)); end return tmp end
code[x_] := If[Less[N[Abs[x], $MachinePrecision], 0.085], N[(N[(x * x), $MachinePrecision] * N[(N[(N[(-2.6455026455026456e-5 * N[(x * x), $MachinePrecision] + 0.0003527336860670194), $MachinePrecision] * N[(x * x), $MachinePrecision] + -0.005555555555555556), $MachinePrecision] * N[(x * x), $MachinePrecision] + 0.16666666666666666), $MachinePrecision]), $MachinePrecision], N[Log[N[(N[Sinh[x], $MachinePrecision] / x), $MachinePrecision]], $MachinePrecision]]
\begin{array}{l}
\\
\begin{array}{l}
\mathbf{if}\;\left|x\right| < 0.085:\\
\;\;\;\;\left(x \cdot x\right) \cdot \mathsf{fma}\left(\mathsf{fma}\left(\mathsf{fma}\left(-2.6455026455026456 \cdot 10^{-5}, x \cdot x, 0.0003527336860670194\right), x \cdot x, -0.005555555555555556\right), x \cdot x, 0.16666666666666666\right)\\
\mathbf{else}:\\
\;\;\;\;\log \left(\frac{\sinh x}{x}\right)\\
\end{array}
\end{array}
herbie shell --seed 2024103
(FPCore (x)
:name "bug500, discussion (missed optimization)"
:precision binary64
:alt
(if (< (fabs x) 0.085) (* (* x x) (fma (fma (fma -2.6455026455026456e-5 (* x x) 0.0003527336860670194) (* x x) -0.005555555555555556) (* x x) 0.16666666666666666)) (log (/ (sinh x) x)))
(log (/ (sinh x) x)))