Q's about use of is_gimple_reg_rhs/is_gimple_tmp_var

[Nathanael Nerode]

In is_gimple_reg_rhs, it says:

  /* If the RHS of the MODIFY_EXPR may throw or make a nonlocal goto and
     the LHS is a user variable, then we need to introduce a temporary.
     ie temp = RHS; LHS = temp.

     This way the optimizers can determine that the user variable is
     only modified if evaluation of the RHS does not throw.  */

Is this really referring to "user variables" (!DECL_ARTIFICIAL), and is
it essentially for debugging?

Or is it referring to something else entirely?

And if so, *what*?

-- 
This space intentionally left blank.