From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: by sourceware.org (Postfix, from userid 48) id 6BB7C3857C63; Wed, 19 Jan 2022 08:33:17 +0000 (GMT) DKIM-Filter: OpenDKIM Filter v2.11.0 sourceware.org 6BB7C3857C63 From: "crazylht at gmail dot com" To: gcc-bugs@gcc.gnu.org Subject: [Bug target/103771] [12 Regression] Missed vectorization under -mavx512f -mavx512vl after r12-5489 Date: Wed, 19 Jan 2022 08:33:17 +0000 X-Bugzilla-Reason: CC X-Bugzilla-Type: changed X-Bugzilla-Watch-Reason: None X-Bugzilla-Product: gcc X-Bugzilla-Component: target X-Bugzilla-Version: 12.0 X-Bugzilla-Keywords: missed-optimization X-Bugzilla-Severity: normal X-Bugzilla-Who: crazylht at gmail dot com X-Bugzilla-Status: NEW X-Bugzilla-Resolution: X-Bugzilla-Priority: P3 X-Bugzilla-Assigned-To: unassigned at gcc dot gnu.org X-Bugzilla-Target-Milestone: 12.0 X-Bugzilla-Flags: X-Bugzilla-Changed-Fields: Message-ID: In-Reply-To: References: Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable X-Bugzilla-URL: http://gcc.gnu.org/bugzilla/ Auto-Submitted: auto-generated MIME-Version: 1.0 X-BeenThere: gcc-bugs@gcc.gnu.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Gcc-bugs mailing list List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Wed, 19 Jan 2022 08:33:17 -0000 https://gcc.gnu.org/bugzilla/show_bug.cgi?id=3D103771 --- Comment #29 from Hongtao.liu --- (In reply to Richard Biener from comment #28) > (In reply to Hongtao.liu from comment #25) > > in fold_unary_loc > > ---cut from fold-const.cc----- > > 9276 else if (TREE_CODE (arg0) =3D=3D COND_EXPR) > > 9277 { > > 9278 tree arg01 =3D TREE_OPERAND (arg0, 1); > > 9279 tree arg02 =3D TREE_OPERAND (arg0, 2); > > 9280 if (! VOID_TYPE_P (TREE_TYPE (arg01))) > > 9281 arg01 =3D fold_build1_loc (loc, code, type, > > 9282 fold_convert_loc (loc, > > 9283 TREE_TYPE (op0), > > arg01)); > > 9284 if (! VOID_TYPE_P (TREE_TYPE (arg02))) > > 9285 arg02 =3D fold_build1_loc (loc, code, type, > > 9286 fold_convert_loc (loc, > > 9287 TREE_TYPE (op0), > > arg02)); > > 9288=3D> tem =3D fold_build3_loc (loc, COND_EXPR, type, TREE_OP= ERAND > > (arg0, 0), > > 9289 arg01, arg02); > >=20 > > -----------end--------------- > >=20 > > gcc always tries to simplify (convert (cond (cmp a b) c d) ---- > (cond= (cmp > > a b) (convert c) (convert d))=EF=BC=8C exactly the opposite of what thi= s case wants. >=20 > It also then undos this if the result didn't simplify and plays trick to > avoid > recursions. >=20 > I think this particular transform ought to be specialized, maybe to > (T)p?(T')a:(T')b or maybe done during gimplification or RTL expansion onl= y. >=20 > The "cheap" way of avoiding a conflict is to wrap the match.pd pattern > with opposite logic in >=20 > #if GIMPLE > #endif >=20 It doesn't work,=20 > (with a comment explaining this) >=20 > Note that we can move a conversion out only if the sources of the convers= ions > have compatible types but we always can move a conversion in. >=20 > Alternatively this transform can also be done in a vectorizer pattern bas= ed > on vector compatibility of the ?: predicate with the data. yes, I'm thinking of doing this in fold_build_cond_expr which is only used = by pass_ifcvt to generate cond_expr.=