I see. Thanks very much! Chaoran > On Apr 23, 2015, at 12:06 PM, Andrew Haley <aph@xxxxxxxxxx> wrote: > > On 04/23/2015 05:58 PM, Chaoran Yang wrote: >> Since I specified ptr as an input, I assume GCC should not try to reuse the register. Am I missing a constraint here? What should I do to tell GCC to not to use the same register for ldarx instruction? > > Your output needs an earlyclobber. : "=&r" (old) > > Andrew. > >
