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RE: Question about find modifiable mems



-----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


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