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

[noloader at gmail dot com]

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

--- Comment #13 from Jeffrey Walton <noloader at gmail dot com> ---
(In reply to Jonathan Wakely from comment #12)
> What's the error?

My bad...

$ cat test.cxx
// #include <math.h>
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;
}

$ /opt/local/bin/g++-mp-5 -std=c++11 test.cxx -o test.exe
Undefined symbols for architecture ppc:
  "llrint(double)", referenced from:
      _main in ccK6psnG.o
  "llrintf(float)", referenced from:
      _main in ccK6psnG.o
  "llrintl(long double)", referenced from:
      _main in ccK6psnG.o
  "llround(double)", referenced from:
      _main in ccK6psnG.o
  "llroundf(float)", referenced from:
      _main in ccK6psnG.o
  "llroundl(long double)", referenced from:
      _main in ccK6psnG.o
ld: symbol(s) not found for architecture ppc
collect2: error: ld returned 1 exit status