On Wed, Aug 29, 2012 at 3:09 PM, Segher Boessenkool <seg...@kernel.crashing.org> wrote: >>> For things that do mftb with high frequency, maybe you should also add a >>> builtin that does just an mftb, i.e. returns a 32-bit result on 32-bit >>> implementations. >> >> Are you thinking in a function that returns only the TBL? > > On 32-bit, just TBL; on 64-bit, the whole TB (there is no machine > instruction to read just TBL on 64-bit, so it doesn't make much > sense to have it return a 32-bit number).
It sounds like you are asking for an additional interface for high-frequency events that only reads one register on both PPC32 and PPC64. I do not believe that interface currently exists for PPC in GLibc and that seems out of the scope of this patch. It could be a nice feature, but it's a new feature request that is not necessary for this round of patches. Thanks, David
