https://gcc.gnu.org/bugzilla/show_bug.cgi?id=117216
--- Comment #1 from vincenzo Innocente <vincenzo.innocente at cern dot ch> --- sorry last entry in the bug report should have been innocent@vinmacscreen binary64 % c++ -O3 -march=native sqrt.cpp -D_GLIBCXX_USE_C99_COMPLEX=0; ./a.out (-4,-0) (0,2) 4 -3.14159 -0 positive -0 negative (1.22465e-16,-2) to demonstrate the defect for no C99 math
