On 25/07/2008, at 8:55 AM, Duncan Coutts wrote:
Right. GHC on SPARC has also always disabled the register window when running Haskell code (at least for registerised builds) and only uses it when using the C stack and calling C functions.
I'm not sure whether register windows and continuation based back-ends are ever going to be very good matches - I don't remember the last time I saw a 'ret' instruction in the generated code :). If there's a killer application for register windows in GHC it'd be something tricky. I'd be more interested in the 8 x hardware threads per core, [1] suggests that (single threaded) GHC code spends over half its time stalled due to L2 data cache miss. 64 threads per machine is a good incentive for trying out a few `par` calls.. Ben. [1] http://www.cl.cam.ac.uk/~am21/papers/msp02.ps.gz