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From: "rguenth at gcc dot gnu.org" <gcc-bugzilla@gcc.gnu.org> To: gcc-bugs@gcc.gnu.org Subject: [Bug tree-optimization/100801] Aggressive loop optimizations cause incorrect warning Date: Fri, 28 May 2021 10:54:26 +0000 [thread overview] Message-ID: <bug-100801-4-BWM0VvON1s@http.gcc.gnu.org/bugzilla/> (raw) In-Reply-To: <bug-100801-4@http.gcc.gnu.org/bugzilla/> https://gcc.gnu.org/bugzilla/show_bug.cgi?id=100801 Richard Biener <rguenth at gcc dot gnu.org> changed: What |Removed |Added ---------------------------------------------------------------------------- Component|ipa |tree-optimization Keywords| |diagnostic, | |missed-optimization Status|UNCONFIRMED |ASSIGNED Ever confirmed|0 |1 Last reconfirmed| |2021-05-28 Assignee|unassigned at gcc dot gnu.org |rguenth at gcc dot gnu.org --- Comment #1 from Richard Biener <rguenth at gcc dot gnu.org> --- Confirmed. We're warning on the obviously unreachable loop since: <bb 4> [local count: 1073741824]: _35 = 12; if (_35 != 12) goto <bb 7>; [75.00%] else goto <bb 6>; [25.00%] $3 = <basic_block 0x7ffff434b680 (4)> since we apply final value replacement to 'i' in sccp but do not propagate it before the next number of iteration analysis in ivcanon: NEXT_PASS (pass_tree_loop_init); NEXT_PASS (pass_tree_unswitch); NEXT_PASS (pass_scev_cprop); <<<< final value repl. NEXT_PASS (pass_loop_split); NEXT_PASS (pass_loop_versioning); NEXT_PASS (pass_loop_jam); /* All unswitching, final value replacement and splitting can expose empty loops. Remove them now. */ NEXT_PASS (pass_cd_dce, false /* update_address_taken_p */); NEXT_PASS (pass_iv_canon); <<<<< warning NEXT_PASS (pass_loop_distribution); NEXT_PASS (pass_linterchange); NEXT_PASS (pass_copy_prop); <<<<<< propagation IIRC final value replacement used to propagate and fold but I(?) removed this at some point.
next prev parent reply other threads:[~2021-05-28 10:54 UTC|newest] Thread overview: 10+ messages / expand[flat|nested] mbox.gz Atom feed top 2021-05-27 14:03 [Bug ipa/100801] New: " jl_gccbugs at conductive dot de 2021-05-28 10:54 ` rguenth at gcc dot gnu.org [this message] 2021-05-28 12:45 ` [Bug tree-optimization/100801] " jl_gccbugs at conductive dot de 2021-07-31 0:41 ` matthijsvanduin at gmail dot com 2021-12-20 0:55 ` [Bug tree-optimization/100801] [9/10/11/12 Regression] " pinskia at gcc dot gnu.org 2022-01-05 14:29 ` rguenth at gcc dot gnu.org 2022-05-27 9:45 ` [Bug tree-optimization/100801] [10/11/12/13 " rguenth at gcc dot gnu.org 2022-06-28 10:45 ` jakub at gcc dot gnu.org 2023-07-07 10:40 ` [Bug tree-optimization/100801] [11/12/13/14 " rguenth at gcc dot gnu.org 2024-03-11 3:42 ` [Bug tree-optimization/100801] [11/12 " law at gcc dot gnu.org
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