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From: "pinskia at gcc dot gnu.org" <gcc-bugzilla@gcc.gnu.org> To: gcc-bugs@gcc.gnu.org Subject: [Bug tree-optimization/109960] [10/11/12/13/14 Regression] missing combining of `(a&1) != 0 || (a&2)!=0` into `(a&3)!=0` Date: Thu, 25 May 2023 02:51:32 +0000 [thread overview] Message-ID: <bug-109960-4-w53BXFbjns@http.gcc.gnu.org/bugzilla/> (raw) In-Reply-To: <bug-109960-4@http.gcc.gnu.org/bugzilla/> https://gcc.gnu.org/bugzilla/show_bug.cgi?id=109960 --- Comment #4 from Andrew Pinski <pinskia at gcc dot gnu.org> --- I happened to notice this because I am working on a match patch that transform `a ? 1 : b` into `a | b`. In the case of stmt_can_terminate_bb_p, I noticed we had: <bb 31> [local count: 330920071]: _48 = MEM[(const struct gasm *)t_22(D)].D.129035.D.128905.D.128890.subcode; _49 = _48 & 2; if (_49 != 0) goto <bb 33>; [34.00%] else goto <bb 32>; [66.00%] <bb 32> [local count: 218407246]: _50 = (bool) _48; <bb 33> [local count: 940291388]: # _13 = PHI <0(14), _50(32), _12(29), 0(11), 0(30), 1(2), 1(31), 0(25)> And the patch to match would do: <bb 31> [local count: 330920071]: _48 = MEM[(const struct gasm *)t_22(D)].D.129035.D.128905.D.128890.subcode; _49 = _48 & 2; _50 = (bool) _48; _127 = _49 != 0; _44 = _50 | _127; <bb 32> [local count: 940291388]: # _13 = PHI <0(14), 0(25), _12(29), 0(11), 0(30), 1(2), _44(31)> Which is definitely better than before but I was like isn't that the same as: _49 = _48 & 3; _44 = _49 != 0;
next prev parent reply other threads:[~2023-05-25 2:51 UTC|newest] Thread overview: 12+ messages / expand[flat|nested] mbox.gz Atom feed top 2023-05-25 0:40 [Bug tree-optimization/109960] New: " pinskia at gcc dot gnu.org 2023-05-25 0:41 ` [Bug tree-optimization/109960] " pinskia at gcc dot gnu.org 2023-05-25 0:45 ` pinskia at gcc dot gnu.org 2023-05-25 0:58 ` pinskia at gcc dot gnu.org 2023-05-25 2:29 ` pinskia at gcc dot gnu.org 2023-05-25 2:51 ` pinskia at gcc dot gnu.org [this message] 2023-05-25 7:59 ` rguenth at gcc dot gnu.org 2023-07-07 10:45 ` [Bug tree-optimization/109960] [11/12/13/14 " rguenth at gcc dot gnu.org 2023-09-16 22:55 ` pinskia at gcc dot gnu.org 2023-09-16 23:04 ` pinskia at gcc dot gnu.org 2023-09-17 1:27 ` pinskia at gcc dot gnu.org 2024-01-12 13:53 ` rguenth at gcc dot gnu.org
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