http://gcc.gnu.org/bugzilla/show_bug.cgi?id=50325
--- Comment #15 from Dominique d'Humieres <dominiq at lps dot ens.fr> 2011-11-17 16:33:59 UTC --- > As the tests from Ian Sandoe and Dominique d'Humieres show, the Darwin/AIX > regressions disappear when limiting the extract_bit_field invocation to > fieldmode == BLKmode (as it was in the "Experimental fix" attached to the > bugzilla). I confirm that revision 181405 breaks the tests in gcc.dg-struct-layout-1/* on powerpc-apple-darwin9 with -m32 (but not with -m64). These failures are gone if I revert r181405 and reapply the "Experimental fix" I have tested before.