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. 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.
Jeff
