* m4/roundf.m4 (gl_FUNC_ROUNDF): Search for roundf() in the libraries
also when it is not declared. Set HAVE_ROUNDF. For replacement code,
test HAVE_ROUNDF, not HAVE_DECL_ROUNDF.
* modules/roundf (configure.ac): For replacement code, test
HAVE_ROUNDF, not HAVE_DECL_ROUNDF.
(Depends-on): Update conditions.
* modules/roundf-ieee (Depends-on): Update conditions.
* doc/posix-functions/roundf.texi: Mention the IRIX problem.
* m4/roundf.m4 (gl_FUNC_ROUNDF): Test also the sign of roundf (-0.3f).
* modules/roundf-ieee (Depends-on): Add floorf-ieee, ceilf-ieee.
* doc/posix-functions/roundf.texi: Mention problem with negative
arguments.
* doc/posix-functions/ceilf.texi: Mention problem on OSF/1 5.1.
* modules/roundf-ieee: New file.
* m4/roundf.m4 (gl_FUNC_ROUNDF): If gl_FUNC_ROUNDF_IEEE is also used,
test whether roundf works according to ISO C 99 with IEC 60559.
* m4/roundf-ieee.m4: New file.
* modules/roundf-ieee-tests: New file.
* tests/test-roundf-ieee.c: New file, based on tests/test-roundf1.c.
* tests/test-roundf1.c (main): Remove signbit tests.
* modules/roundf-tests (Depends-on): Remove 'signbit'.
* doc/posix-functions/roundf.texi: Mention the new module.