We can clean some of this up when doing the Windows64 port. Then wait for the jit to support the functionality, and switch the default.
On 2/2/07, Xiao-Feng Li <[EMAIL PROTECTED]> wrote:
Thanks, Aleksey. Well, it's not that easy. The object header layout change has interactions with some other modules like threading. And my original question is not about how to hack the code base for non-compressed pointer. I was just thinking it might be a good idea to make compressed pointer only a toggle-able optimization. Thanks, xiaofeng On 2/2/07, Aleksey Ignatenko <[EMAIL PROTECTED]> wrote: > I suppose there is no easy way to do that, but one can scan all places where > > #ifdef _EM64T_ appears and change appropriate places to something like > #ifdef _COMPRESSED_MODE. Plus scan such places like gc_types.h in gc_cc, > there is object header: > VT32 vt_raw; > unsigned info; > You need to have VT64 vt_raw; for 64 bit mode. > > p.s. In some of discussions I read that compressed mode (comparing to > uncompressed one) improved performance on about 13% on em64t. > > On 2/2/07, Xiao-Feng Li <[EMAIL PROTECTED]> wrote: > > > Yes, that's exactly my question. I couldn't find an easy way to turn > > off this compressed-ptr optimization. It's a little bit surprising me. > > :-) > > > > Thanks, > > xiaofeng > > > > On 2/2/07, Aleksey Ignatenko <[EMAIL PROTECTED]> wrote: > > > Did you check that it works on 64 bit mode with uncomressed references. > > > I remember some time ago there were issues like hard coded compressed > > > references used in JIT (or probably somewhere else) in 64bit mode. > > > > > > Best regards, > > > Aleksey. > > > > > > On 2/2/07, Xiao-Feng Li <[EMAIL PROTECTED]> wrote: > > > > > > > > Hi, current 64bit support uses compressed reference pointer by > > > > default, i.e., a 64bit reference is stored as a 32bit value plus a > > > > (global) base address. This can reduce the footprint of working set > > > > and at the same time improve cache locality. But this has max heap > > > > size limitation. > > > > > > > > I wonder why not use non-compressed pointer as by default, and the > > > > compressed pointer is only an optimization that can be applied when > > > > desirable. Comments? > > > > > > > > Thanks, > > > > xiaofeng > > > > > > > > > > > > > >
