On Tue, May 24, 2011 at 1:31 PM, Kirill Batuzov <batuz...@ispras.ru> wrote: [...] > Gathered statistics shows some interesting things too. I've run matrix > multiplication benchmark (guest - ARM, host - x86, linux-user mode, with > my patches applied) and here are the results: > > spill count 3916 > real spills 32 > spills at bb end 1023 > spills at call: > globals 2755 > iarg passing 0 > call cloobers 106 > > Real spills are spills generated by register allocator when it runs out > of registers. They are less than 1% of all spills. Other tests show > similar behavior.
When you write "host x86", do you mean IA32 or x86_64? That might change the number of real spills a lot if you meant x86_64. > I think any further improvements to register allocator without leveling > conventions about saving globals at calls and BB ends somehow is > useless. > > Currently we are looking if we can pass some globals on registers > through basic block boundaries (inside one TB of course). If by "basic block", you mean BB as implied by TCG br for instance, I'm not sure all guests will benefit a lot. If you mean that you intend on putting several guests BB in a single TB then I guess you'll have to first collect dynamic statistics before dynamically switching to grouping BB. Laurent
