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From: "pinskia at gcc dot gnu.org" <gcc-bugzilla@gcc.gnu.org>
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Subject: [Bug tree-optimization/103857] implement ternary without jump (and
 comparison)
Date: Wed, 29 Dec 2021 20:26:08 +0000
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https://gcc.gnu.org/bugzilla/show_bug.cgi?id=3D103857

--- Comment #4 from Andrew Pinski <pinskia at gcc dot gnu.org> ---
(In reply to Andrew Pinski from comment #3)
> Reduced testcase:
> int f(int a, int b, int c)
> {
>   if (a !=3D b && a !=3D c) __builtin_unreachable();
>   return a =3D=3D b ? b : c;
> }
>=20
> This should just translate into:
> int f1(int a, int b, int c)
> {
>   if (a !=3D b && a !=3D c) __builtin_unreachable();
>   return a;
> }
>=20
> The ^ part is not needed really if it is just selecting between two value=
s.

Oh it was swapping around the two values:

int f(int a, int b, int c)
{
  if (a !=3D b && a !=3D c) __builtin_unreachable();
  return a =3D=3D b ? c : b;
}
int f1(int a, int b, int c)
{
  if (a !=3D b && a !=3D c) __builtin_unreachable();
  return a ^ b ^ c;
}

And then the ^ are needed.=