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From: "linkw at gcc dot gnu.org" <gcc-bugzilla@gcc.gnu.org> To: gcc-bugs@gcc.gnu.org Subject: [Bug target/106069] [12/13 Regression] wrong code with -O -fno-tree-forwprop -maltivec on ppc64le Date: Wed, 03 Aug 2022 08:50:46 +0000 [thread overview] Message-ID: <bug-106069-4-wmbosBp5QH@http.gcc.gnu.org/bugzilla/> (raw) In-Reply-To: <bug-106069-4@http.gcc.gnu.org/bugzilla/> https://gcc.gnu.org/bugzilla/show_bug.cgi?id=106069 --- Comment #23 from Kewen Lin <linkw at gcc dot gnu.org> --- > Ideally we would avoid semantic difference of RTL depending on the target. > If that's not avoidable there should be target macros/hooks that specify > the desired semantics. Not sure, IMHO it seems it doesn't depend on the target but on endianness (BYTES_BIG_ENDIAN)? Segher and Mike may have more insights on this. > I assume the semantic difference is in > vec_concat behavior but that's just documented as > > @findex vec_concat > @item (vec_concat:@var{m} @var{x1} @var{x2}) > Describes a vector concat operation. The result is a concatenation of the > vectors or scalars @var{x1} and @var{x2}; its length is the sum of the > lengths of the two inputs. > > which is a bit unspecific. To me it implies that > vec_select of a single lane N of the concat result can be distributed > to the operands of the vec_concat in the obvious way (if N >= > GET_MODE_NUNITS (x1) subtract GET_MODE_NUNITS and use x2) Yeah, the documentation isn't clear, neither for vec_select. I guess vec_select also matters here, the indexes for vec_select would have the LE ordering like subreg byte offset on LE?
next prev parent reply other threads:[~2022-08-03 8:50 UTC|newest] Thread overview: 39+ messages / expand[flat|nested] mbox.gz Atom feed top 2022-06-23 23:13 [Bug target/106069] New: " mpolacek at gcc dot gnu.org 2022-06-23 23:15 ` [Bug target/106069] [12/13 Regression] " mpolacek at gcc dot gnu.org 2022-06-23 23:18 ` mpolacek at gcc dot gnu.org 2022-06-24 3:25 ` luoxhu at gcc dot gnu.org 2022-06-24 13:03 ` mpolacek at gcc dot gnu.org 2022-06-30 8:13 ` luoxhu at gcc dot gnu.org 2022-06-30 8:15 ` luoxhu at gcc dot gnu.org 2022-06-30 17:32 ` segher at gcc dot gnu.org 2022-06-30 17:34 ` segher at gcc dot gnu.org 2022-07-01 1:52 ` luoxhu at gcc dot gnu.org 2022-07-25 15:54 ` rguenth at gcc dot gnu.org 2022-07-25 20:16 ` segher at gcc dot gnu.org 2022-07-25 20:18 ` segher at gcc dot gnu.org 2022-07-26 3:34 ` luoxhu at gcc dot gnu.org 2022-07-26 3:34 ` luoxhu at gcc dot gnu.org 2022-07-26 3:35 ` luoxhu at gcc dot gnu.org 2022-07-26 3:53 ` luoxhu at gcc dot gnu.org 2022-07-26 6:28 ` luoxhu at gcc dot gnu.org 2022-07-29 11:10 ` rguenth at gcc dot gnu.org 2022-07-29 11:21 ` rguenth at gcc dot gnu.org 2022-08-03 6:10 ` yinyuefengyi at gmail dot com 2022-08-03 6:38 ` yinyuefengyi at gmail dot com 2022-08-03 8:06 ` linkw at gcc dot gnu.org 2022-08-03 8:24 ` rguenther at suse dot de 2022-08-03 8:50 ` linkw at gcc dot gnu.org [this message] 2022-08-03 8:59 ` rguenth at gcc dot gnu.org 2022-08-03 9:20 ` rsandifo at gcc dot gnu.org 2022-08-03 9:25 ` rsandifo at gcc dot gnu.org 2022-08-03 18:01 ` segher at gcc dot gnu.org 2022-08-03 18:06 ` segher at gcc dot gnu.org 2022-08-04 9:17 ` rsandifo at gcc dot gnu.org 2022-08-04 9:21 ` rearnsha at gcc dot gnu.org 2022-08-04 9:59 ` yinyuefengyi at gmail dot com 2022-08-04 10:01 ` yinyuefengyi at gmail dot com 2023-01-16 18:00 ` jakub at gcc dot gnu.org 2023-03-24 16:16 ` jakub at gcc dot gnu.org 2023-03-24 17:01 ` bergner at gcc dot gnu.org 2023-03-31 2:57 ` yinyuefengyi at gmail dot com 2023-05-08 12:24 ` [Bug target/106069] [12/13/14 " rguenth at gcc dot gnu.org
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