[PATCH] D40177: performance improvements for ThunderX2 T99

[Stefan Teleman via Phabricator via llvm-commits]

steleman added inline comments.


================
Comment at: test/CodeGen/AArch64/loop-micro-op-buffer-size-t99.ll:6
+
+; CHECK: Loop Unroll: F[foo] Loop %loop.2.header
+; CHECK: Loop Size = 19
----------------
davide wrote:
> steleman wrote:
> > davide wrote:
> > > I don't understand why this change is related to loop-unrolling, can you please elaborate?
> > > I don't understand why this change is related to loop-unrolling, can you please elaborate?
> > 
> > I am not sure I understand your question.
> > 
> > Are you referring to the entire test case, or just to the two lines above your comment?
> > 
> > If you are asking about the entire test case, then the answer is: the change in the T99 scheduler is about loop unrolling, and only about loop unrolling. It's not about anything else.
> > 
> > 
> > 
> > 
> Can you please check in the test standalone and update the change to show the difference?
I can't check in because I don't have check-in privileges. :-)

But I uploaded the relevant files to my Google Drive:

https://drive.google.com/open?id=18GseEsH4XN6bjD3UAcSB06GkXhWzPSAf

(Please let me know if you have problems accessing that directory; I don't think you should; I set it to world-readable).

There are 3 files in there:

1. t99-loop-unrolling-without-scheduler-patch.txt
-- That's the output from opt from LLVM Git 2017/11/16 **without** my scheduler patch.

2. t99-loop-unrolling-with-scheduler-patch.txt
-- That's the output from opt from LVM Git 2017/11/16 **with** my scheduler patch.

3. loop.c
-- That's a test/experiment that I wrote/used to test the changes in CodeGen triggered by the change in the scheduler. It's an interesting test.

If you have the time, and the inclination, you can use loop.c to track what happens to the loop at different optimization levels (-O1, -O2, -O3).





Repository:
  rL LLVM

https://reviews.llvm.org/D40177