
(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 3 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 (* 0.027777777777777776 (* x (/ x (fma (pow x 2.0) 0.005555555555555556 0.16666666666666666)))))
double code(double x) {
return 0.027777777777777776 * (x * (x / fma(pow(x, 2.0), 0.005555555555555556, 0.16666666666666666)));
}
function code(x) return Float64(0.027777777777777776 * Float64(x * Float64(x / fma((x ^ 2.0), 0.005555555555555556, 0.16666666666666666)))) end
code[x_] := N[(0.027777777777777776 * N[(x * N[(x / N[(N[Power[x, 2.0], $MachinePrecision] * 0.005555555555555556 + 0.16666666666666666), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
0.027777777777777776 \cdot \left(x \cdot \frac{x}{\mathsf{fma}\left({x}^{2}, 0.005555555555555556, 0.16666666666666666\right)}\right)
\end{array}
Initial program 62.4%
Taylor expanded in x around 0 97.9%
*-commutative97.9%
Simplified97.9%
flip-+97.9%
associate-*r/97.8%
metadata-eval97.8%
swap-sqr97.8%
pow-prod-up97.8%
metadata-eval97.8%
metadata-eval97.8%
*-commutative97.8%
cancel-sign-sub-inv97.8%
metadata-eval97.8%
Applied egg-rr97.8%
*-commutative97.8%
associate-/l*97.9%
sub-neg97.9%
distribute-rgt-neg-in97.9%
metadata-eval97.9%
+-commutative97.9%
*-commutative97.9%
fma-define97.9%
Simplified97.9%
Taylor expanded in x around 0 98.1%
unpow298.1%
associate-/l*98.1%
Applied egg-rr98.1%
Final simplification98.1%
(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 62.4%
Taylor expanded in x around 0 97.8%
add-sqr-sqrt97.7%
pow297.7%
*-commutative97.7%
sqrt-prod97.8%
sqrt-pow197.8%
metadata-eval97.8%
pow197.8%
Applied egg-rr97.8%
*-commutative97.8%
unpow-prod-down97.8%
pow297.8%
rem-square-sqrt97.8%
unpow297.8%
associate-*r*97.9%
Applied egg-rr97.9%
Final simplification97.9%
(FPCore (x) :precision binary64 5.0)
double code(double x) {
return 5.0;
}
real(8) function code(x)
real(8), intent (in) :: x
code = 5.0d0
end function
public static double code(double x) {
return 5.0;
}
def code(x): return 5.0
function code(x) return 5.0 end
function tmp = code(x) tmp = 5.0; end
code[x_] := 5.0
\begin{array}{l}
\\
5
\end{array}
Initial program 62.4%
Taylor expanded in x around 0 97.9%
*-commutative97.9%
Simplified97.9%
flip-+97.9%
associate-*r/97.8%
metadata-eval97.8%
swap-sqr97.8%
pow-prod-up97.8%
metadata-eval97.8%
metadata-eval97.8%
*-commutative97.8%
cancel-sign-sub-inv97.8%
metadata-eval97.8%
Applied egg-rr97.8%
*-commutative97.8%
associate-/l*97.9%
sub-neg97.9%
distribute-rgt-neg-in97.9%
metadata-eval97.9%
+-commutative97.9%
*-commutative97.9%
fma-define97.9%
Simplified97.9%
Taylor expanded in x around 0 98.1%
Taylor expanded in x around inf 4.2%
Final simplification4.2%
(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 2024060
(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)))