Sebastian Huber <sebastian.huber@embedded-brains.de> writes:

> It seems to be present in only some multilibs:

I did some more digging -- the 'common' one is getting built, but the
resulting math library doesn't have it included, which (as you suggest)
indicates a problem in the build system. It turns out that the autotools
build requires that all filenames across the whole math library must be
unique; having 's_fma.c' in both common and machine/arm causes the one
from common to be overwritten by the one in machine/arm due to the
manual construction of libm.a from the constituent sub-libraries.

As all of my testing was using meson instead of autotools, I guess I
shouldn't be surprised that I broke the autotools build.

I've sent a patch that renames libm/machine/arm/*fma.c and that appears
to fix the problem.

-- 
-keith