Hi, gcc-ow...@gcc.gnu.org wrote on 24/01/2011 03:21:51 PM:
> Hello, > Some of our target processors support complete hardware misaligned > memory access. I implemented movmisalignm patterns, and found > TARGET_SUPPORT_VECTOR_MISALIGNMENT > (TARGET_VECTORIZE_SUPPORT_VECTOR_MISALIGNMENT > On 4.6) hook is based on checking these patterns. Somehow this > hook doesn't seem to be used. vect_enhance_data_refs_alignment > is called regardless whether the target has HW misaligned support > or not. targetm.vectorize.support_vector_misalignment is used in vect_supportable_dr_alignment to decide whether a specific misaligned access is supported. > > Shouldn't using HW misaligned memory access be better than > generating extra code for loop peeling/versioning? Or at least > if for some architectures it is not the case, we should have > a compiler hook to choose between them. BTW, I mainly work > on 4.5, maybe 4.6 has changed. Right. And we have that implemented in 4.6 at least partially: for known misalignment and for peeling for loads. Maybe this part needs to be enhanced, concrete testcases could help. Ira > > Thanks, > Bingfeng Mei >
