------- Comment #4 from rguenth at gcc dot gnu dot org 2008-01-05 18:24 ------- I wouldn't read the language this way. Because that will forcefully disable all redundancy removing optimizations (which is what happens in this testcase). What it currently guards is expression rewriting that changes the outcome if a rounding mode different than round-to-nearest is used.
The finer-grained control the documentation mentions should not be globbed to -frounding-math IMHO. -- http://gcc.gnu.org/bugzilla/show_bug.cgi?id=34678
