[Bug tree-optimization/67628] [tree-optimization] (a && b) && c shows better codegen than a && (b && c)

[pinskia at gcc dot gnu.org via Gcc-bugs]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=67628

--- Comment #6 from Andrew Pinski <pinskia at gcc dot gnu.org> ---
Another testcase which shows the problem to be even worse:
#define isgap(c) ((c) == ' ' || (c) == '.' || (c) == '_' || (c) == '-' || (c)
== '~')

int f(char a)
{
  return isgap(a);
}