Things are a bit quiet this morning so I wandered over to my freebsd  
intel box and downloaded
the unix 3.5-development tar file and build an intel squeak vm.

I used a interp.c  I had (from june 30th)  which was a bit newer, but  
followed the same pattern as the one that Ian is shipping, gnuified,  
use of global structure foo, use of AHC changeset to localize variables  
in the interpreter

For the 3.6.1bx interp.c that used
BitOfGCTuning-JMM
which removes the +1 in the headerTypeBytes lookup, plus some  
localization for the mark/sweep
InterpreterFixes-3Point6 from Andreas
CodeGenEnh-3Point6 from Andreas
MakePrimPointXInternal-JMM which makes point x/y internal in the  
interp.c
allocateNoFillHashTable-JMM which has improved allocation/nofill &  
hashtable lookup.

Not quite the same, however in running tinybenchmarks I noted

june 30thVM 40,738,383 bytecode/sec 972,076 sends/sec
3.6.1bxVM     40,429,564 bytecodes/sec 984,169 sends/sec

Similar performance, but the 3.6.1bxVM has better sends/second. Due to  
the CodeGenEnh I think...
Certainly one is not extraordinary faster than the other.

However  when I looked at allocation rates for 1 asFloat,  2 at 3, Array  
new: 5 I saw

june30thVM 37,654, 40,198, 31,037

3.6.1bxVM    75,952,  82,524, 39,325

Ah, much nicer, also quite remarkable as compared to the powerpc  
benchmarks.

These changes did translate into a savings in the macrobenchmarks.
371,654 versus 376,568
It's hard to say if the better performance is due to allocation, or to  
faster sends/second.
however cutting small object allocation time by 50%should show up  
somewhere.

Someone will need to do a better degree of testing, to better reflect  
just the hashtable/ old hash differences? Versus  my wholesale  
before/after testing. And of course try this under windows.

PS The intel box is a dual pentium 350Mhz, which ran 49.5% busy during  
the testing.
gcc version 2.95.4 was used, gcc 3.3.x might do a better job?

--
======================================================================== 
===
John M. McIntosh <johnmci at smalltalkconsulting.com> 1-800-477-2659
Corporate Smalltalk Consulting Ltd.  http://www.smalltalkconsulting.com
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