Hi, I am reading the documentation of CALL_USED_REGISTERS and can't help but thing there is a typo (even though it is more probable that I am not understanding the documentation). It says: "Like FIXED_REGISTERS but has 1 for each register that is clobbered (in general) by function calls as well as for fixed registers. ... If a register has 0 in CALL_USED_REGISTERS, the compiler automatically saves it on function entry and restores it on function exit, if the register is used within the function. " Is it has a 1, then it means that the register is clobbered. And 0 means it is not clobbered. But if it is not clobbered, why does the compiler need to save it on function entry and restore it on function exit? I am not getting it... Thanks, -- Paulo Jorge Matos - pocmatos at gmail.com http://www.pmatos.net