[Bug c++/64677] New: incorrect result with complex division?

["spatel at rotateright dot com" <gcc-bugzilla at gcc dot gnu dot org>]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=64677

            Bug ID: 64677
           Summary: incorrect result with complex division?
           Product: gcc
           Version: 4.9.2
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: c++
          Assignee: unassigned at gcc dot gnu.org
          Reporter: spatel at rotateright dot com

I'm not sure if this is a bug at -O0, at -O1 (in MPFR because all math is
folded out in this case?), or neither:

#include <complex>
#include <iostream>
#include <iomanip>

int main()
{
    std::complex<double> c(-61.887073591767951,-60.052083270252012);
    double a = (1.0 / c).real();

    std::cout << std::setprecision(17) << " " << a << std::endl;
}

$ g++ complex_div.cpp -O0 -std=c++11
$ ./a.out 
 -0.0083223357032193145
$ g++ complex_div.cpp -O1 -std=c++11
$ ./a.out 
 -0.0083223357032193128


Using built-in specs.
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