[Bug libstdc++/79017] Old PowerMac G5, MacPorts GCC 5.4, C++11 and "std::log2 has not been declared"

[redi at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=79017

--- Comment #10 from Jonathan Wakely <redi at gcc dot gnu.org> ---
(In reply to Jeffrey Walton from comment #9)
> This patch for libc++ may be useful to you for OS X 10.6 and below (thanks
> to KC):
> https://github.com/jeremyhu/libcxx/commit/
> 720feba4874d4ca3131753dc31af127e3c509c36

Hmm, that doesn't match your results above that say the missing functions for
10.5 (Leopard) are the llrint and llround ones.

It would be strange if they added llround to Snow Leopard but removed lrint.

Does this C program compile and link on 10.4 and 10.5?

long long llrint(double x);
long long llrintf(float x);
long long llrintl(long double x);
long long llround(double x);
long long llroundf(float x);
long long llroundl(long double x);

int main()
{
  llrint(0.0);
  llrintf(0.0f);
  llrintl(0.0l);
  llround(0.0);
  llroundf(0.0f);
  llroundl(0.0l);
  return 0;
}