> so the fix is to simply not optimize here? Yes, we cannot turn a BIT_FIELD_REF with rev-storage into a VIEW_CONVERT_EXPR.
> Are there correctness issues with the patterns we have for rev-storage? But > then some cases are let through via the realpart/imagpart/v_c_e case? I > suppose we should never see REF_REVERSE_STORAGE_ORDER on refs operating on > registers (SSA_NAMEs or even is_gimple_reg()s)? REF_REVERSE_STORAGE_ORDER is set on BIT_FIELD_REF and MEM_REF only. > Note that I think you need to adjust the GENERIC side as well, for example > > [...] > > where we lose the reverse-storage attribute as well. You'd probably > have to cut out rev-storage refs somewhere in genmatch.c. I don't think that's necessary since we never fold top-level BIT_FIELD_REFs at the GENERIC level so far. And given that it's impossible to control the top level in match.pd, I'd rather not try something impossible unless rforced to do it. This ought to be controlled directly from fold-const.c, if need be. -- Eric Botcazou
