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* [Bug tree-optimization/101120] New: vn_reference_maybe_forwprop_address can take much compile-time @ 2021-06-18 11:33 rguenth at gcc dot gnu.org 2021-06-18 11:33 ` [Bug tree-optimization/101120] " rguenth at gcc dot gnu.org ` (3 more replies) 0 siblings, 4 replies; 5+ messages in thread From: rguenth at gcc dot gnu.org @ 2021-06-18 11:33 UTC (permalink / raw) To: gcc-bugs https://gcc.gnu.org/bugzilla/show_bug.cgi?id=101120 Bug ID: 101120 Summary: vn_reference_maybe_forwprop_address can take much compile-time Product: gcc Version: 11.1.1 Status: UNCONFIRMED Severity: normal Priority: P3 Component: tree-optimization Assignee: unassigned at gcc dot gnu.org Reporter: rguenth at gcc dot gnu.org Target Milestone: --- For polyhedron doduc.f90 I see tree FRE : 5.05 ( 47%) 0.03 ( 14%) 5.16 ( 46%) 5780k ( 3%) with -Ofast -march=haswell and tree iv optimization : 4.99 ( 40%) 0.13 ( 33%) 5.28 ( 40%) 218M ( 51%) with -Ofast Resulting from the vectorizer generating chains of constant adds (_1 = _2 + 8 + 8 + 8 + 8 spread across multiple stmts). There's duplicate bugs for this around but a possible cheap mitigation would be to fold those to create cheaper to walk use-def chains for the passes between vectorization and the next forwprop pass. ^ permalink raw reply [flat|nested] 5+ messages in thread
* [Bug tree-optimization/101120] vn_reference_maybe_forwprop_address can take much compile-time 2021-06-18 11:33 [Bug tree-optimization/101120] New: vn_reference_maybe_forwprop_address can take much compile-time rguenth at gcc dot gnu.org @ 2021-06-18 11:33 ` rguenth at gcc dot gnu.org 2021-06-18 12:06 ` rguenth at gcc dot gnu.org ` (2 subsequent siblings) 3 siblings, 0 replies; 5+ messages in thread From: rguenth at gcc dot gnu.org @ 2021-06-18 11:33 UTC (permalink / raw) To: gcc-bugs https://gcc.gnu.org/bugzilla/show_bug.cgi?id=101120 Richard Biener <rguenth at gcc dot gnu.org> changed: What |Removed |Added ---------------------------------------------------------------------------- Assignee|unassigned at gcc dot gnu.org |rguenth at gcc dot gnu.org Last reconfirmed| |2021-06-18 Ever confirmed|0 |1 Keywords| |compile-time-hog Status|UNCONFIRMED |ASSIGNED --- Comment #1 from Richard Biener <rguenth at gcc dot gnu.org> --- I'll see to do that. ^ permalink raw reply [flat|nested] 5+ messages in thread
* [Bug tree-optimization/101120] vn_reference_maybe_forwprop_address can take much compile-time 2021-06-18 11:33 [Bug tree-optimization/101120] New: vn_reference_maybe_forwprop_address can take much compile-time rguenth at gcc dot gnu.org 2021-06-18 11:33 ` [Bug tree-optimization/101120] " rguenth at gcc dot gnu.org @ 2021-06-18 12:06 ` rguenth at gcc dot gnu.org 2021-06-21 13:02 ` cvs-commit at gcc dot gnu.org 2021-06-21 13:03 ` rguenth at gcc dot gnu.org 3 siblings, 0 replies; 5+ messages in thread From: rguenth at gcc dot gnu.org @ 2021-06-18 12:06 UTC (permalink / raw) To: gcc-bugs https://gcc.gnu.org/bugzilla/show_bug.cgi?id=101120 --- Comment #2 from Richard Biener <rguenth at gcc dot gnu.org> --- Created attachment 51034 --> https://gcc.gnu.org/bugzilla/attachment.cgi?id=51034&action=edit patch That fixes the attached but we also have loads of dead loads around which exposes the IV opts issue at -Ofast where IVOPTs analyzes all the dead loads with zero-use LHS. While we have PUSH_INSERT_PASSES_WITHIN (pass_vectorize) NEXT_PASS (pass_dce); POP_INSERT_PASSES () there's no such attempt after SLP passes. But pruning the DR chain after SLP permute is possible as another hack. ^ permalink raw reply [flat|nested] 5+ messages in thread
* [Bug tree-optimization/101120] vn_reference_maybe_forwprop_address can take much compile-time 2021-06-18 11:33 [Bug tree-optimization/101120] New: vn_reference_maybe_forwprop_address can take much compile-time rguenth at gcc dot gnu.org 2021-06-18 11:33 ` [Bug tree-optimization/101120] " rguenth at gcc dot gnu.org 2021-06-18 12:06 ` rguenth at gcc dot gnu.org @ 2021-06-21 13:02 ` cvs-commit at gcc dot gnu.org 2021-06-21 13:03 ` rguenth at gcc dot gnu.org 3 siblings, 0 replies; 5+ messages in thread From: cvs-commit at gcc dot gnu.org @ 2021-06-21 13:02 UTC (permalink / raw) To: gcc-bugs https://gcc.gnu.org/bugzilla/show_bug.cgi?id=101120 --- Comment #3 from CVS Commits <cvs-commit at gcc dot gnu.org> --- The master branch has been updated by Richard Biener <rguenth@gcc.gnu.org>: https://gcc.gnu.org/g:0ad9c7087ef3904da89f2db6007b6d28b116087f commit r12-1699-g0ad9c7087ef3904da89f2db6007b6d28b116087f Author: Richard Biener <rguenther@suse.de> Date: Fri Jun 18 14:07:00 2021 +0200 tree-optimization/101120 - fix compile-time issue with SLP groups This places two hacks to avoid an old compile-time issue when vectorizing large permuted SLP groups with gaps where we end up emitting loads and IV adjustments for the gap as well and those have quite a high cost until they are eventually cleaned up. The first hack is to fold the auto-inc style IV updates early in the vectorizer rather than in the next forwprop pass which shortens the SSA use-def chains of the used IV. The second hack is to remove the unused loads after we've picked all that we possibly use. 2021-06-18 Richard Biener <rguenther@suse.de> PR tree-optimization/101120 * tree-vect-data-refs.c (bump_vector_ptr): Fold the built increment. * tree-vect-slp.c (vect_transform_slp_perm_load): Add DR chain DCE capability. * tree-vectorizer.h (vect_transform_slp_perm_load): Adjust. * tree-vect-stmts.c (vectorizable_load): Remove unused loads in the DR chain for SLP. ^ permalink raw reply [flat|nested] 5+ messages in thread
* [Bug tree-optimization/101120] vn_reference_maybe_forwprop_address can take much compile-time 2021-06-18 11:33 [Bug tree-optimization/101120] New: vn_reference_maybe_forwprop_address can take much compile-time rguenth at gcc dot gnu.org ` (2 preceding siblings ...) 2021-06-21 13:02 ` cvs-commit at gcc dot gnu.org @ 2021-06-21 13:03 ` rguenth at gcc dot gnu.org 3 siblings, 0 replies; 5+ messages in thread From: rguenth at gcc dot gnu.org @ 2021-06-21 13:03 UTC (permalink / raw) To: gcc-bugs https://gcc.gnu.org/bugzilla/show_bug.cgi?id=101120 Richard Biener <rguenth at gcc dot gnu.org> changed: What |Removed |Added ---------------------------------------------------------------------------- Status|ASSIGNED |RESOLVED Resolution|--- |FIXED --- Comment #4 from Richard Biener <rguenth at gcc dot gnu.org> --- Fixed. ^ permalink raw reply [flat|nested] 5+ messages in thread
end of thread, other threads:[~2021-06-21 13:03 UTC | newest] Thread overview: 5+ messages (download: mbox.gz / follow: Atom feed) -- links below jump to the message on this page -- 2021-06-18 11:33 [Bug tree-optimization/101120] New: vn_reference_maybe_forwprop_address can take much compile-time rguenth at gcc dot gnu.org 2021-06-18 11:33 ` [Bug tree-optimization/101120] " rguenth at gcc dot gnu.org 2021-06-18 12:06 ` rguenth at gcc dot gnu.org 2021-06-21 13:02 ` cvs-commit at gcc dot gnu.org 2021-06-21 13:03 ` rguenth at gcc dot gnu.org
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