[fpc-devel] optimizing the peephole optimizer?

Martin Frb lazarus at mfriebe.de
Wed Jan 22 00:06:47 CET 2014


On 21/01/2014 21:20, Florian Klämpfl wrote:
> Am 19.01.2014 18:01, schrieb Martin:
>> In each of them GetNextInstruction(p, hp1) could be executed.
>>
>> If I counted correct, it can be called up to 6 times for each a_mov.
>> On the other hand:
>> - no code in this case block, is ever executed, if it does not succeed.
>> - It will always be executed at least once
>>
>> So it would probably be better to have this once at the start of the
>> A_MOV block.
>>
>>
>> If that makes sense, I can check other blocks for similar issues.
> I guess the idea is to catch typical code sequences in one go, see also
> the comment in 1243:
> { Next instruction is also a MOV ? }
So then a patch would be accepted to move the check for
    GetNextInstruction(p, hp1)
to the start, and have one single such condition, in one IF block, that 
will contain all the others?






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