[tree-ssa] Why are bools cast to int in conditionals?

[Dan Nicolaescu]

"Joseph S. Myers" <jsm@polyomino.org.uk> writes:

  > On Wed, 21 Apr 2004, Dan Nicolaescu wrote:
  > 
  > > In more "complex" cases the casts are not be eliminated by the tree
  > > optimizers:
  > > 
  > > _Bool foo (_Bool a, _Bool b)
  > > {
  > >   if (a != b)
  > 
  > Here, the usual arithmetic conversions are applied to the operands of !=,
  > which includes the integer promotions, which promote _Bool to int.

Is _Bool different from other types in this respect? short, chars and
enums don't seem to get the same treatment. 

Are there any operators that don't require the promotion of _Bool to
int?