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pankajchawla (Pankaj Chawla)
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User Since
Jul 11 2016, 2:04 PM (161 w, 5 d)

Recent Activity

Mar 2 2018

pankajchawla accepted D41467: PR35710: Nary reassociation falls into infinite loop.
Mar 2 2018, 5:27 PM

Sep 12 2016

pankajchawla added inline comments to D22377: [SCEV] trip count calculation for loops with unknown stride.
Sep 12 2016, 11:43 PM
pankajchawla added inline comments to D22377: [SCEV] trip count calculation for loops with unknown stride.
Sep 12 2016, 5:36 PM
pankajchawla updated the diff for D22377: [SCEV] trip count calculation for loops with unknown stride.

Changes to address Sanjoy's comments.

Sep 12 2016, 5:25 PM

Sep 2 2016

pankajchawla added a comment to D22377: [SCEV] trip count calculation for loops with unknown stride.

@Eli
Thanks for the info!

Sep 2 2016, 2:32 PM
pankajchawla updated the diff for D22377: [SCEV] trip count calculation for loops with unknown stride.

Fixed max backedge count computation for loops with unknown stride by assuming a min stride of 1.

Sep 2 2016, 2:31 PM
pankajchawla added a comment to D22377: [SCEV] trip count calculation for loops with unknown stride.

Hi all,

Sep 2 2016, 1:35 PM

Aug 25 2016

pankajchawla added a comment to D22377: [SCEV] trip count calculation for loops with unknown stride.

Thanks for the additional info!

Aug 25 2016, 3:10 PM

Aug 18 2016

pankajchawla added a comment to D22377: [SCEV] trip count calculation for loops with unknown stride.

I can't find anything wrong with the IR. I am awaiting your response for more information.

Aug 18 2016, 9:36 PM

Aug 16 2016

pankajchawla added a comment to D22377: [SCEV] trip count calculation for loops with unknown stride.

Please ignore my previous email. My analysis was incorrect. The stride cannot be negative here as it will lead to UB.

Aug 16 2016, 9:09 PM
pankajchawla added a comment to D22377: [SCEV] trip count calculation for loops with unknown stride.

Hi Sanjoy,

Aug 16 2016, 4:03 PM

Aug 9 2016

pankajchawla added inline comments to D22377: [SCEV] trip count calculation for loops with unknown stride.
Aug 9 2016, 12:12 PM
pankajchawla updated the diff for D22377: [SCEV] trip count calculation for loops with unknown stride.

Added more elaborate comments explaining why the change is correct.

Aug 9 2016, 12:10 PM

Aug 8 2016

pankajchawla added inline comments to D22377: [SCEV] trip count calculation for loops with unknown stride.
Aug 8 2016, 3:08 PM

Aug 2 2016

pankajchawla added inline comments to D22377: [SCEV] trip count calculation for loops with unknown stride.
Aug 2 2016, 1:08 PM
pankajchawla updated the diff for D22377: [SCEV] trip count calculation for loops with unknown stride.

Added bailout condition for predicated IVs.

Aug 2 2016, 12:26 PM

Jul 26 2016

pankajchawla updated D22377: [SCEV] trip count calculation for loops with unknown stride.
Jul 26 2016, 4:18 PM
pankajchawla updated the diff for D22377: [SCEV] trip count calculation for loops with unknown stride.
  • Added check to prove that the stride is truly unknown to ScalarEvolution so that the wrap flags are not propagated in edge cases.
  • Removed unnecessary check for loopHasNoAbnormalExits() and loop entry guard.
  • Fixed comments and the test.
Jul 26 2016, 4:17 PM
pankajchawla added inline comments to D22377: [SCEV] trip count calculation for loops with unknown stride.
Jul 26 2016, 3:21 PM
pankajchawla added inline comments to D22377: [SCEV] trip count calculation for loops with unknown stride.
Jul 26 2016, 2:52 PM
pankajchawla added a comment to D22377: [SCEV] trip count calculation for loops with unknown stride.

Hi Sanjoy,

Jul 26 2016, 1:21 PM

Jul 22 2016

pankajchawla added a comment to D22377: [SCEV] trip count calculation for loops with unknown stride.

Hi Sanjoy,

Jul 22 2016, 3:56 PM
pankajchawla updated D22377: [SCEV] trip count calculation for loops with unknown stride.
Jul 22 2016, 3:35 PM
pankajchawla added a comment to D22377: [SCEV] trip count calculation for loops with unknown stride.

Hi Sanjoy,

Jul 22 2016, 1:54 PM
pankajchawla updated the diff for D22377: [SCEV] trip count calculation for loops with unknown stride.

Added check for side effects in the loop.

Jul 22 2016, 1:19 PM

Jul 20 2016

pankajchawla requested review of D22377: [SCEV] trip count calculation for loops with unknown stride.

Bumping this up again.

Jul 20 2016, 12:33 PM

Jul 15 2016

pankajchawla added a comment to D22377: [SCEV] trip count calculation for loops with unknown stride.

Hi Sanjoy,

Jul 15 2016, 10:39 AM

Jul 14 2016

pankajchawla updated the diff for D22377: [SCEV] trip count calculation for loops with unknown stride.

Added check for loopHasNoAbnormalExits() and a comment about bailing out for do-while loops.

Jul 14 2016, 5:08 PM
pankajchawla added inline comments to D22377: [SCEV] trip count calculation for loops with unknown stride.
Jul 14 2016, 1:24 PM
pankajchawla added a comment to D22377: [SCEV] trip count calculation for loops with unknown stride.

You have to be a bit more careful here... consider:

for (int i=0; i<16; i-=2) {
    if (i < -2000) break;
}

Here, the backedge is taken 1000 times. (There are actually two related cases here: one, the case where there's an explicit break, and the case where some call in the loop throws an exception.)

It might be sufficient to show that the loop only has one exit and loopHasNoAbnormalExits() is true; not 100% sure about that.

Jul 14 2016, 1:17 PM
pankajchawla retitled D22377: [SCEV] trip count calculation for loops with unknown stride from to [SCEV] trip count calculation for loops with unknown stride.
Jul 14 2016, 12:09 PM