On my Alpine Linux 3.13/powerpcle system, the fmaf configure test is reported
as "checking whether fmaf works... no". As far as I can see, it's a QEMU bug.
Let me document it here.
2021-01-31 Bruno Haible <br...@clisp.org>
fmaf: Document QEMU bug.
* doc/posix-functions/fmaf.texi: Add note about QEMU bug.
diff --git a/doc/posix-functions/fmaf.texi b/doc/posix-functions/fmaf.texi
index 1e0d34a..3551d19 100644
--- a/doc/posix-functions/fmaf.texi
+++ b/doc/posix-functions/fmaf.texi
@@ -18,4 +18,8 @@ glibc 2.11, Mac OS X 10.5, FreeBSD 6.4/x86, FreeBSD 12.2/arm,
Cygwin 1.5, mingw.
Portability problems not fixed by Gnulib:
@itemize
+@item
+This function produces wrong results on some platforms:
+musl libc/powerpc64le when emulated by QEMU 5.0.0.
+@c https://bugs.launchpad.net/qemu/+bug/1912934
@end itemize
