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*From*: pinskia at gmail dot com*To*: Richard Biener <rguenther at suse dot de>*Cc*: GCC Mailing List <gcc at gcc dot gnu dot org>*Date*: Thu, 6 Nov 2014 23:39:14 -0800*Subject*: Re: Match-and-simplify and COND_EXPR*Authentication-results*: sourceware.org; auth=none*References*: <CA+=Sn1=ZrkDn8FS-5qFvh-ndF2isFD9xBQmE_gLvA6qAVmE02w at mail dot gmail dot com> <alpine dot LSU dot 2 dot 11 dot 1411061126240 dot 27850 at zhemvz dot fhfr dot qr> <alpine dot LSU dot 2 dot 11 dot 1411061138230 dot 27850 at zhemvz dot fhfr dot qr> <CA+=Sn1=3tTc54x87WFQM3+GZeUF9UK35zbWVdY2ymcfqNEMC6A at mail dot gmail dot com> <E7DC8C10-4AAF-44D9-B3E6-4ABEAB027A62 at suse dot de>

> On Nov 6, 2014, at 11:24 PM, Richard Biener <rguenther@suse.de> wrote: > >> On November 7, 2014 5:03:19 AM CET, Andrew Pinski <pinskia@gmail.com> wrote: >> On Thu, Nov 6, 2014 at 2:40 AM, Richard Biener <rguenther@suse.de> >> wrote: >>> On Thu, 6 Nov 2014, Richard Biener wrote: >>> >>>>> On Wed, 5 Nov 2014, Andrew Pinski wrote: >>>>> >>>>> Hi, >>>>> I was trying to hook up tree-ssa-phiopt to match-and-simplify >> using >>>>> either gimple_build (or rather using gimple_simplify depending on >> if >>>>> we want to produce cond_expr for conditional move). I ran into a >>>>> problem. >>>>> With the pattern below: >>>>> /* a ? 0 : 1 -> a if 0 and 1 are integral types. */ >>>>> (simplify >>>>> (cond_expr @0 integer_zerop integer_onep) >>>>> (if (INTEGRAL_TYPE_P (type)) >>>>> (convert @0))) >>>> >>>> Ok, so you are capturing a GENERIC expr here but nothing knows that. >>>> It would work if you'd do (ugh) >>>> >>>> (for op (lt le eq ne ge gt) >>>> (simplify >>>> (cond_expr (op @0 @1) integer_zerop integer_onep) >>>> (if (INTEGRAL_TYPE_P (type)) >>>> (convert (op @0 @1))))) >>>> (simplify >>>> (cond_expr SSA_NAME@0 integer_zerop integer_onep) >>>> (if (INTEGRAL_TYPE_P (type)) >>>> (convert @0)))) >>>> >>>> as a workaround. To make your version work will require (quite) >>>> some special-casing in the code generator or maybe the resimplify >>>> helper. Let me see if I can cook up a "simple" fix. >>> >>> Sth like below (for the real fix this has to be replicated in >>> all gimple_resimplifyN functions). I'm missing a testcase >>> where the pattern would apply (and not be already folded by fold), >>> so I didn't check if it actually works. >> >> You do need to check if seq is NULL though as gimple_build depends on >> seq not being NULL. But otherwise yes this works for me. >> >>> >>> Bah, of course we should fix COND_EXPRs to not embed a GENERIC >>> expr... >> >> Yes totally agree. For my changes to tree-ssa-phiopt, I no longer >> embed it. Though we need to change loop ifconvert still. > > Istr expansion or code quality does not like us to cse the condition of two cobd_exprs either. After all I had a patch set at some point doing that conversion (though as well for gimple_conds). I thought I changed that when I did the expansion of cond_expr into conditional move. We need to something similar for cond_expr of jumps too. Thanks, Andrew > > Richard. > >> Thanks, >> Andrew >> >>> >>> Richard. >>> >>> Index: gcc/gimple-match-head.c >>> =================================================================== >>> --- gcc/gimple-match-head.c (revision 217035) >>> +++ gcc/gimple-match-head.c (working copy) >>> @@ -90,6 +90,13 @@ gimple_resimplify1 (gimple_seq *seq, >>> code_helper *res_code, tree type, tree *res_ops, >>> tree (*valueize)(tree)) >>> { >>> + /* ??? Stupid tcc_comparison GENERIC trees in COND_EXPRs. */ >>> + if (COMPARISON_CLASS_P (res_ops[0])) >>> + res_ops[0] = gimple_build (seq, >>> + TREE_CODE (res_ops[0]), TREE_TYPE >> (res_ops[0]), >>> + TREE_OPERAND (res_ops[0], 0), >>> + TREE_OPERAND (res_ops[0], 1)); >>> + >>> if (constant_for_folding (res_ops[0])) >>> { >>> tree tem = NULL_TREE; >>> > >

**Follow-Ups**:**Re: Match-and-simplify and COND_EXPR***From:*Richard Biener

**References**:**Match-and-simplify and COND_EXPR***From:*Andrew Pinski

**Re: Match-and-simplify and COND_EXPR***From:*Richard Biener

**Re: Match-and-simplify and COND_EXPR***From:*Richard Biener

**Re: Match-and-simplify and COND_EXPR***From:*Andrew Pinski

**Re: Match-and-simplify and COND_EXPR***From:*Richard Biener

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