[Bug middle-end/53081] memcpy/memset loop recognition

[xinliangli at gmail dot com]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=53081

--- Comment #4 from davidxl <xinliangli at gmail dot com> 2012-04-23 05:34:55 UTC ---
(In reply to comment #2)
> I should mention I made one patch before based on the vectorizer code which did
> detection of at least memset; it was while I was an intern at Apple.  I posted
> it and there was some review.  And a few years back there was a paper at the
> GCC summit about it and expanding it to memcpy.  I don't know what happened to
> that code though.

Some simple analysis using scev to identify loads and stores with linear
address should be good enough. 

LLVM's version also tries to merge smaller memsets into a larger one.