[Mono-list] Need some short answers on the new Mono JIT / Mini

Tom Fransen t.fransen@mailned.nl
Tue, 27 May 2003 22:34:34 +0100


Hi,

I have a few questions about the new JIT:

- My first question is: were can I find the document on mini that is
mentioned in the release notes???
I searched the Mono TAR files but I cannot find it. I don't know if it is
stored in CVS.
I have no experience with CVS , who can help me out here?


- If I start a program I can use the option -O=all to enable all
optimizations.
Which optimizations are used when I do not use the -O option, what are the
default optimizations ???

- I assume that the mono JIT compiles the code on a method basis (like MS
JIT).
Based on this assumption I measured the time for the first and second
invocation
of a very small method. The idea is that on the first invocation the JIT
comes into action
and as a result the time to execute the method is longer than for the second
invocation.
( I executed this test on run-level 1 so that very few process are running)
On my machine (1333MHz) I measured an initial threshold of ~200us.

However if I use the -O=all option the difference in duration between the
first
and the second invocation is almost zero!!
So in other words there is no initial cost for the JIT.
Can anybody explain why this is???????????

Please help me out here!

regards,
Tom Fransen

PS: I'm doing some measurement on Mono as part of an assignment, in case you
guys are wondering
what this strange person is upto!