------- Comment #9 from rguenth at gcc dot gnu dot org 2009-08-26 18:35 ------- Note that even for
(long long)i * (long long)j * (long long)i we can only use one mulsidi3, so promoting parts of the multiplications to additions should be still beneficial. I suppose we should detect widening multiply on the tree level before re-association where it is beneficial (if the target doesn't have a native wide multiplication). -- http://gcc.gnu.org/bugzilla/show_bug.cgi?id=29274
