This is the mail archive of the gcc@gcc.gnu.org mailing list for the GCC project.


Index Nav: [Date Index] [Subject Index] [Author Index] [Thread Index]
Message Nav: [Date Prev] [Date Next] [Thread Prev] [Thread Next]
Other format: [Raw text]

Using BUILT_IN_ATOMIC_...


Hello all,

I am trying to use BUILT_IN_ATOMIC_..., but it does not quite work. I am calling them as:

  tmp = builtin_decl_explicit (BUILT_IN_ATOMIC_LOAD_4);
  tmp = build_call_expr_loc (input_location, tmp, 2, atom.expr, ...

That gives the following dump:

  __atomic_store_n (&i, 5, 0);
  __atomic_store_n (&i, (integer(kind=4)) *k, 0);
  j = (integer(kind=4)) __atomic_load_4 (&i, 0);
  __atomic_add_fetch (&i, 5, 0);


The "__atomic_load_4" works, but the "__atomic_store_n" and "__atomic_add_fetch" lead to link-time errors:

  fo4o.f90:(.text+0x44): undefined reference to `__atomic_store_n'
  fo4o.f90:(.text+0x73): undefined reference to `__atomic_add_fetch'


The issue with `__atomic_store_n', I can solve by replacing it by, e.g., BUILT_IN_ATOMIC_STORE_4. However, how does one properly use __atomic_add_fetch alias BUILT_IN_ATOMIC_ADD_FETCH_N, given that there is no _4 version of it?


Additionally, if one wants to fetch the old value (e.g. with __atomic_add_fetch), how does one properly use the function result? The problem is that TREE_TYPE() doesn't automatically match the type of the first argument. Ignoring the type issue in the front end and simply calling MODIFY_EXPR will lead to a gimplify.c ICE.

Tobias


Index Nav: [Date Index] [Subject Index] [Author Index] [Thread Index]
Message Nav: [Date Prev] [Date Next] [Thread Prev] [Thread Next]