TraceTypeProfile as diagnostic option (original) (raw)

Vladimir Kozlov vladimir.kozlov at oracle.com
Mon Sep 10 11:28:52 PDT 2012

Aleksey Shipilev wrote:

On 09/10/2012 09:22 PM, Vladimir Kozlov wrote:

We need to be careful here. It will increase product VM size (currently that code is under #ifndef PRODUCT) and embedded group will kill us for that. I think we should look on this case by case. You still can figure out that it is bimorphic call since they have the same bci (@ 4). What is the reasonable increase in VM size we (they) could tolerate? I

None :) Seriously, they pushed several changes just to save few bytes in our internal data structures.

can make the prototype change and figure out the actual increase. Looks like there is a single small printing subroutine and two calls.

The subroutine will be inlined in call sites so total size increase will be bigger than one method. But increase may be disappear during linking due to alignment, merge and other staff. So, please, do the experiment.

Also we need to consider how often it will be used outside VM development work by customers. If customers are not using it we need to avoid including it into product. You always can build VM (fastdebug or optimized) where such flags work.

Vladimir

-Aleksey.

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