[Bug tree-optimization/126963] [17 Regression] 6% slowdown of lbm on Zen5 since r17-2817-g5e45cc08f3bbbf

"rguenth at gcc dot gnu.org via Gcc-bugs" <[email protected]> Thu, 20 Aug 2026 12:46:19 +0000

Newsgroups	gmane.comp.gcc.bugs
Message-ID	<[email protected]/bugzilla/>

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=126963

--- Comment #1 from Richard Biener <rguenth at gcc dot gnu.org> ---
Are you sure...?  This simply avoids


  _1 = ...;
  _2 = _1;   <- .... this copy
  ... = use (_2);

but IIRC lbm, is notoriously "unstable".