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RE: Question about find modifiable mems
- From: Ajit Kumar Agarwal <ajit dot kumar dot agarwal at xilinx dot com>
- To: shmeel gutl <shmeelgutl at shmuelhome dot mine dot nu>, GCC Development <gcc at gcc dot gnu dot org>
- Date: Wed, 3 Jun 2015 07:33:46 +0000
- Subject: RE: Question about find modifiable mems
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-----Original Message-----
From: gcc-owner@gcc.gnu.org [mailto:gcc-owner@gcc.gnu.org] On Behalf Of shmeel gutl
Sent: Wednesday, June 03, 2015 12:10 PM
To: GCC Development
Subject: Question about find modifiable mems
>>find_modifiable_mems was introduced to gcc 4.8 in september 2012. Is there any documentation as to how it is supposed to help the haifa scheduler?
>>In my private port of gcc it make the following type of transformations
>>from
>>a= *(b+20)
>>b+=30
>>to
>> b+=30
>>a=*(b-10)
>>Although this is functionally correct, it has changed an ANTI_DEP into a TRUE_DEP and thus introduced stalls. If it went the other way, that would be good. >>Any pointers?
Breaking Anti-Dependencies is an important optimization for transformation like Vectorization.
Thanks & Regards
Ajit
Thanks,
Shmeel