https://gcc.gnu.org/bugzilla/show_bug.cgi?id=80902
--- Comment #1 from Segher Boessenkool <segher at gcc dot gnu.org> --- Author: segher Date: Fri Jun 23 17:37:27 2017 New Revision: 249603 URL: https://gcc.gnu.org/viewcvs?rev=249603&root=gcc&view=rev Log: Fix expand_builtin_atomic_fetch_op for pre-op (PR80902) __atomic_add_fetch adds a value to some memory, and returns the result. If there is no direct support for this, expand_builtin_atomic_fetch_op is asked to implement this as __atomic_fetch_add (which returns the original value of the mem), followed by the addition. Now, the __atomic_add_fetch could have been a tail call, but we shouldn't perform the __atomic_fetch_add as a tail call: following code would not be executed, and in fact thrown away because there is a barrier after tail calls. This fixes it. PR middle-end/80902 * builtins.c (expand_builtin_atomic_fetch_op): If emitting code after a call, force the call to not be a tail call. Modified: trunk/gcc/ChangeLog trunk/gcc/builtins.c
