[cfe-dev] Size suffix ignored in atomic builtins?

[Mikhail Zolotukhin via cfe-dev]

Hi,

Currently atomic intrinsics are overloaded by the datatype. That allow us to use a non-suffixed version for any data-type, like this:
  signed char sc;
  void foo(void) {
    (void) __sync_fetch_and_add(&sc, 1);
  }
instead of explicitly specifying data-type, as here:
  signed char sc;
  void foo(void) {
    (void) __sync_fetch_and_add_1(&sc, 1);
  }

For both of these examples clang generates
  %0 = atomicrmw add i8* @sc, i8 1 seq_cst

However, it looks like due to this overloading, we completely ignore the size suffix. For instance, for 
  signed char sc;
  void foo(void) {
    (void) __sync_fetch_and_add_4(&sc, 1);
  }

clang will generate the same IR with i8:
  %0 = atomicrmw add i8* @sc, i8 1 seq_cst ; << i8, instead of i32


Is it an expected behavior, or a bug?

Thanks,
Michael
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