2015-08-21 18:57 GMT+03:00 Jeff Law <l...@redhat.com>: > On 08/21/2015 06:30 AM, Ilya Enkovich wrote: >> >> 2015-08-20 21:41 GMT+03:00 Jeff Law <l...@redhat.com>: >>>>> >>>>> 2015-08-17 Ilya Enkovich <enkovich....@gmail.com> >>>> >>>> >>>> * expr.c (expand_expr_real_2): Support GEN_MASK_EXPR. >>>> * gimple-pretty-print.c (dump_unary_rhs): Likewise. >>>> * gimple.c (get_gimple_rhs_num_ops): Likewise. >>>> * optabs.c: Include gimple.h. >>>> (vector_compare_rtx): Add OPNO arg. >>>> (get_gen_mask_icode): New. >>>> (expand_gen_mask_expr_p): New. >>>> (expand_gen_mask_expr): New. >>>> (expand_vec_cond_expr): Adjust vector_compare_rtx call. >>>> * optabs.def (gen_mask_optab): New. >>>> (gen_masku_optab): New. >>>> * optabs.h (expand_gen_mask_expr_p): New. >>>> (expand_gen_mask_expr): New. >>>> * tree-cfg.c (verify_gimple_assign_unary): Support >>>> GEN_MASK_EXPR. >>>> * tree-inline.c (estimate_operator_cost): Likewise. >>>> * tree-pretty-print.c (dump_generic_node): Likewise. >>>> * tree-ssa-operands.c (get_expr_operands): Likewise. >>>> * tree.def (GEN_MASK_EXPR): New. >>> >>> >>> A general question, would any of this likely help Yuri's work to optimize >>> MASK_STORES? >> >> >> If I remember correctly his optimization is for Haswell which doesn't >> have scalar masks. But doing it with scalar masks would be simpler >> because zero mask check becomes trivial. > > I was thinking mostly about the mask check. > > > >>> So if the target doesn't have suitable insns, what happens? I suspect >>> the >>> answer is nothing useful. In which case the question becomes what >>> prevents >>> the optimizers from generating a GEN_MASK_EXPR? Maybe that'll become >>> clear >>> as I read the rest of the patches. >> >> >> I don't expect other optimizer than vectorizer to generate it. And as >> usually optab is checked before generating it. > > If we're checking an optab to drive an optimization, then we're probably on > the wrong track.
That's totally similar to VEC_COND_EXPR which we generate comparison into. >I think this ties into the overall discussion about > whether or not to represent these masks in gimple or try to handle them > later during gimple->rtl expansion. Currently we don't have any abstraction for masks, it is supported using vector of integers. When I expand it I have no idea whether it is just a vector of integers to be stored or a mask to be used for MASK_LOAD. Actually it may be used in both cases at the same time. Handling it in RTL means we have to undo bool->int transformation made in GIMPLE. For trivial cases it may be easy but in generic it can be challenging. I want to avoid it from the beginning. Thanks, Ilya > > Jeff
