http://gcc.gnu.org/bugzilla/show_bug.cgi?id=51893
--- Comment #7 from Eric Botcazou <ebotcazou at gcc dot gnu.org> 2012-01-20 11:28:26 UTC --- > The testcase that fails is gcc.c-torture/execute/bitfld-3.c. Both with and > without (4.6.1 release) the patch. > The patch I posted fixes the problem, but I don't know if it is general > enough. OK, what are the values of the various parameters you have upon entering the problematic block of code in store_bit_field_1? Note that this code has been working fine for years on 32-bit big-endian targets so this is unexpected.