https://gcc.gnu.org/bugzilla/show_bug.cgi?id=86968
--- Comment #12 from Thomas Preud'homme <thopre01 at gcc dot gnu.org> --- (In reply to Eric Botcazou from comment #11) > > Therefore unaligned access are handled by extract_bit_field. This in turns > > call extract_bit_field_1 and later extract_integral_bit_field where things > > are different between little endian and big endian. For little endian, it > > goes in the following if block: > > > > /* If OP0 is a memory, try copying it to a register and seeing if a > > cheap register alternative is available. */ > > if (MEM_P (op0) & !reverse) > > > > For big endian it continues and calls extract_fixed_bit_field. I'm wondering > > if an extra call to flip_storage_order when reverse is true would solve the > > issue. Need to understand better whe is it safe to call flip_storage_order. > > Where do you want to add a call to flip_storage_order exactly? The correct > thing to do would be to move the !reverse test from the top-level if to the > first inner if (in order to bypass only the extv business) and see what > happens next (and be prepared for adjusting adjust_bit_field_mem_for_reg to > reverse SSO). Forgive my naive question as I'm not too familiar with that part of the compiler: why should the get_best_mem_extraction_insn be guarded with reverse? I thought I'd just ad an if (reverse) if it succeeds and call flip_storage_order there, likewise after the call to extract_bit_field_1 below if successful.
