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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/105135] [11/12/13 Regression] Optimization regression
 for handrolled branchless assignment since r11-4717-g3e190757fa332d32
Date: Sat, 11 Mar 2023 05:29:54 +0000
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https://gcc.gnu.org/bugzilla/show_bug.cgi?id=3D105135

--- Comment #6 from Andrew Pinski <pinskia at gcc dot gnu.org> ---
If we change all char to "unsigned char", it is still different and for
to_lower_3 we get on the tree level:

  if (_1 <=3D 25)
    goto <bb 3>; [34.00%]
  else
    goto <bb 4>; [66.00%]

  <bb 3> [local count: 365072224]:
  _4 =3D c_3(D) + 32;

  <bb 4> [local count: 1073741824]:
  # _2 =3D PHI <_4(3), c_3(D)(2)>

There is another bug for the above which asks to transform this to:
  if (_1 <=3D 25)
    goto <bb 3>; [34.00%]
  else
    goto <bb 4>; [66.00%]

  <bb 3> [local count: 365072224]:
  _4 =3D 32;

  <bb 4> [local count: 1073741824]:
  # _t =3D PHI <_4(3), 0>
_2 =3D c_3(D) + _t;

Which then would get it similar to the other two ...=