Am 11.03.2015 15:37, schrieb Remi Forax:
[...]
Sometime, yes, if you count the frequency of each branch by example,
here is another code that implements a bimorphic inlining cache that
expand to a dispatch table local to a callsite if necessary, I think you
can adapt this code to implement what Mark want quite easily
https://code.google.com/p/jsr292-cookbook/source/browse/trunk/bimorphic-cache/src/jsr292/cookbook/bicache/RT.java
but obviously the DispatchMap case is not something that will be nice to
performance, or not? I am was wondering how performance would drop if I
have an array for counting invocations for each part of the cache as
well as total number of counts and how that would impact performance.
Because obviously on each invocation I would have to call a little
method that does the counting as well as an additional guard to cause
the reorganization once a certain threshold is reached... And I know
every guard will lower performance.
Anyway... based on Marks initial post as well as Remi's idea I would
come up with the following... which is mostly an abstraction and
refactoring of Remi's code.
class InlineCache<T extends MutableCallSite> {
int MAX_DEPTH = 5
int depth
T callsite
...
InlineCache(T callsite) {...}
public void installCache()
public final Object internalFallback(...)
public abstract MH fallback(T callsite, Object[] args)
public abstract MH megamorphicFallback(T callsite, Object[] args)
public final MH insert(MH target, MH... tests)
}
in case of a cache miss and max depth not reached fallback is called and
supposed to call insert for the new target, the method will do the
integration into the cache, and return a handle you can return from
fallback. megamorphicFallback would be called in case of maximum depth
is reached and install for example a virtual dispatch or whatever else.
installCache would the cache logic as target of the callsite.
internalFallback would increase the count as well as calling either
fallback or megamorphicFallback. I didn't want to let the cache extend
the callsite, since others may need the callsite class for their own
purposes. Separation could allow for for example using a different cache
type.
Taking your code from
https://code.google.com/p/jsr292-cookbook/source/browse/trunk/inlining-cache/src/jsr292/cookbook/icache/RT.java
basically line 42 would be in internalFallback 43-45 in
megamorphicFallback, 46-47 in internalFallback, 50-57 in fallback, 56-57
would be the test given to insert, 59-63 in internalFallback, and of
course we would not link to fallback, but to internalFallback
What do you guys think?
bye Jochen
--
Jochen "blackdrag" Theodorou - Groovy Project Tech Lead
blog: http://blackdragsview.blogspot.com/
german groovy discussion newsgroup: de.comp.lang.misc
For Groovy programming sources visit http://groovy-lang.org
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