http://gcc.gnu.org/bugzilla/show_bug.cgi?id=18041
Richard Guenther <rguenth at gcc dot gnu.org> changed: What |Removed |Added ---------------------------------------------------------------------------- Status|NEW |ASSIGNED AssignedTo|unassigned at gcc dot |rguenth at gcc dot gnu.org |gnu.org | --- Comment #4 from Richard Guenther <rguenth at gcc dot gnu.org> 2011-05-06 13:23:11 UTC --- Mine. With bitfield lowering I see <bb 2>: BF.0_2 = MEM[(struct B *)b_1(D)]; D.2686_3 = (<unnamed-unsigned:1>) BF.0_2; D.2687_4 = (unsigned char) D.2686_3; D.2694_6 = BF.0_2 >> 1; D.2688_7 = (<unnamed-unsigned:1>) D.2694_6; D.2689_8 = (unsigned char) D.2688_7; D.2690_9 = D.2689_8 | D.2687_4; D.2691_10 = (<unnamed-unsigned:1>) D.2690_9; D.2696_12 = BF.0_2 & 4294967294; D.2697_13 = (unsigned int) D.2691_10; BF.2_14 = D.2697_13 | D.2696_12; MEM[(struct B *)b_1(D)] = BF.2_14; return; there is the possibility to associate truncations/widenings with |& so D.2689_8 | D.2687_4 becomes (unsigned char) D.2688_7 | D.2686_3 and the truncation (<unnamed-unsigned:1>) D.2690_9 can be combined with it.