Re: [PATCH 0/5] stop collection of instruction usage statistics

[Alex Bennée]

Luis Fernando Fujita Pires <luis.pires@eldorado.org.br> writes:

> From: Alex Bennée <alex.bennee@linaro.org>
>> I have no particular comment to make about the PPC stuff but with the common
>> translator loop we have hooks across all converted front ends to identify the
>> start of each instruction. It's needed for the TCG plugin instrumentation 
>> and we
>> could in theory use it for more integrated stats across the board.
>> 
>> Out of interest what was the main aim of this code - a view of total executed
>> instructions or something more detailed like a breakdown of types and ops?
>
> The legacy instruction decoding logic in the PPC implementation uses a
> table that maps opcode patterns (based on different parts of the
> instructions) to handlers that actually implement each instruction.
> The code that is being removed would list how many times each specific 
> handler was invoked, so it had more information than just the total count of 
> executed instructions.
>
> That being said, the code probably wasn't being used for a while now,
> as it didn't even compile.

Ahh OK. If you wanted to you could probably re-create that information
using the howvec plugin (see contrib/plugins/howvec) if the decode
tables where added for PPC.

-- 
Alex Bennée