On Mon, Jan 21, 2002 at 10:36:26AM -0800, Ulrich Drepper wrote: > "H . J . Lu" <hjl@lucon.org> writes: > > > Ulrich, should applciations have access to thread register directly? > > It doesn't matter. The value isn't changed in the lifetime of a > thread. So the overhead of a syscall wouldn't be too much. And > protection against programs overwriting the register isn't necessary. > It's the program's fault if that happens. Thq question is if we should reserve $23 outside of glibc. $23 is a saved register in the MIPS ABI. It doesn't change across function calls. If applications outside of glibc don't need to access the thread register directly, that means $23 can be used as a saved register. We don't have to change anything when compiling applications. We only need to compile glibc with $23 reserved as the thread register. H.J.
