> It doesn't look like the return value (r8) is actually being set beyond > initialized to 0. If there is some ia64 instruction that modifies it, GCC > doesn't know about it from the inline assembly (r8 doesn't appear in the > inputs/outputs list). From looking at the x86 version (agh, inline asm is > hard to parse), it does modify the return value based on whether the > comparison was a success or not, and the return value is certainly used by > the callers. The commit comment for the change makes it sound like the return value is an error code (-ENOSYS if the function isn't implemented/configured; -EFAULT if the user address is bogus) - or zero if nothing bad happened. Not "the comparison was a success or not". What's the real answer? The ia64 code is returning 0 regardless of whether the compare/exchange found the old value or not. Is this a bad assumption? -Tony ��.n��������+%������w��{.n�����{��&�����ܨ}���Ơz�j:+v�����w����ޙ��&�)ߡ�a����z�ޗ���ݢj��w�f