[Bug libstdc++/78851] Resolve DR 550 in cmath and continue using __builtin_powil() even in C++11

[glisse at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=78851

--- Comment #1 from Marc Glisse <glisse at gcc dot gnu.org> ---
You are misinterpreting Howard's answer. Please show code that currently
doesn't compile and you would like to be able to compile, or code that compiles
(specify the flags used) to asm that isn't as fast as you would like.