* DJ Delorie via Libc-alpha:

> I've been working on updating glibc for Fedora Rawhide, and have
> stumbled upon this issue (after working around the -Wuse-after-free
> issues with a cflags hack)...  A few of the math tests explicitly add
> -mlong-double-64 but configure adds -mabi=ibmlongdouble
>
> I would guess that we need a "CFLAGS -= -mabi=ibmlongdouble" in all
> the places we add -mlong-double-64 but I don't see an easy way of
> doing that, nor am I sure that's a valid solution.  Alternately, gcc
> could be changed to accept the conflicting flags in a meaningful way,
> if there is one.  Is there an -mabi= that undoes the
> -mabi=ibmlongdouble that we can just add to the -mlong-double-64 flag
> lines?

> cc1: error: '-mabi=ibmlongdouble' requires '-mlong-double-128'

I was able to reproduce with a GCC 12 build configured using
--with-long-double-format=ieee.

I tried the attached patch to remove the unwanted -mabi=ibmlongdouble,
but it does not work: it removes CFLAGS-*.c processing as a side effect.

Any suggestions how we can fix this properly?

Thanks,
Florian