[fpc-devel] More peephole

Martin Frb lazarus at mfriebe.de
Thu Jan 23 21:15:37 CET 2014

On 23/01/2014 20:04, Florian Klämpfl wrote:
> Am 23.01.2014 20:52, schrieb Martin Frb:
>> On 23/01/2014 19:35, Florian Klämpfl wrote:
>>> I think this is hard to achive as well.
>> Why?
> I consider it as complicated and it covers only cases one can forsee.
> Some statistical analysis of benchmark timings and procedure sizes is
> imo much more general.

Ok, so we were talking about 2 different targets.

You were talking (if I understand correct) about a general test for any 
and all forms of regressions (with regards to speed or size / not with 
regards to function) in code generation. This is indeed hard to test.
Size may be do able by comparing to a known size that was once archived 
/ size may increase or decrease, but then tests need to be fixed 
(decrease must be fixed, so that increase from the new optimum will then 
be detected.)
Speed is indeed very hard. Since even a benchmark may vary.

I was talking about checking for specific/known code snippets that are 
known to be inefficient (so anything that the peephole generator 
can/could detect). This is only a small subset of the possible 
speed/size regressions, but it is at least something.

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