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From: "pinskia at gcc dot gnu.org" <gcc-bugzilla@gcc.gnu.org>
To: gcc-bugs@gcc.gnu.org
Subject: [Bug target/100623] [10/11/12 Regression] wrong code with -Os
 -fno-dce -fno-defer-pop -fno-forward-propagate -flive-range-shrinkage
 -fno-rerun-cse-after-loop -mno-push-args since r10-7515-g2c0fa3ecf70d199a
Date: Sat, 29 Jan 2022 23:55:14 +0000
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https://gcc.gnu.org/bugzilla/show_bug.cgi?id=3D100623

--- Comment #3 from Andrew Pinski <pinskia at gcc dot gnu.org> ---
There seems to be some IR difference on the gimple level which might be mak=
ing
this latent.
In GCC 11.2.0 we have (bn_add_words) :
  _2 =3D n_3 & -4;
...
  if (_2 !=3D 0)

While on the trunk we have:
  _14 =3D (unsigned int) n_3;
  if (_14 > 3)

This does look like a valid transformation knowing that n is subtracted by =
4.=