Blue Swirl writes: > On Wed, May 11, 2011 at 12:28 AM, Paul Brook <p...@codesourcery.com> wrote: >> In practice generated code probably accesses CPUState often enough that a >> dedicated register isn't a bad idea. My guess is that eliminating it from C >> code gets us almost all of the useful benefit. Removing it from the code >> generator (i.e. TCG_AREG0) may be more pain that it's worth.
> I don't think moving the helpers from op_helper.c to helper.c will be > a performance win if AREG0 is not eliminated. The code gets to use one > register more, but AREG0 needs to be moved to a function argument > register in most cases and AREG0 has to be restored. I think the > benefit should come from generated code getting one more available > register. So, it all boils down to the amount of register spilling that can be avoided in TCG-generated code when eliminating the reserved register for AREG0. Am I right? Lluis -- "And it's much the same thing with knowledge, for whenever you learn something new, the whole world becomes that much richer." -- The Princess of Pure Reason, as told by Norton Juster in The Phantom Tollbooth
