<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=iso-8859-1">
<style type="text/css" style="display:none;"> P {margin-top:0;margin-bottom:0;} </style>
</head>
<body dir="ltr">
<div style="font-family: Calibri, Arial, Helvetica, sans-serif; font-size: 12pt; color: rgb(0, 0, 0);">
Just wanted to share an observation of something I realised last week. <span style="color: rgb(0, 0, 0); font-family: Calibri, Arial, Helvetica, sans-serif; font-size: 12pt; background: var(--white);">We have quite a few passes that are disable by default.
Just looking at the loop passes, then all of these are off by default:</span></div>
<div style="font-family: Calibri, Arial, Helvetica, sans-serif; font-size: 12pt; color: rgb(0, 0, 0);">
<br>
</div>
<div style="font-family: Calibri, Arial, Helvetica, sans-serif; font-size: 12pt; color: rgb(0, 0, 0);">
LoopDistribute
<div>LoopFlatten</div>
<div>LoopInterchange</div>
<div>LoopReroll</div>
<div>LoopUnrollAndJam</div>
<div>LoopVersioningLICM</div>
SimpleLoopUnswitch<br>
</div>
<div style="font-family: Calibri, Arial, Helvetica, sans-serif; font-size: 12pt; color: rgb(0, 0, 0);">
<br>
</div>
<div style="font-family: Calibri, Arial, Helvetica, sans-serif; font-size: 12pt; color: rgb(0, 0, 0);">
Some are probably more specific for a use-case and it's just good to have certain transformations in our toolbox, but I guess what I want to say is that it looks like there are opportunities to get more of these on by default, although I appreciate of course
that will involve a bit of work. For example, <span style="color: rgb(0, 0, 0); font-family: Calibri, Arial, Helvetica, sans-serif; font-size: 12pt; background: var(--white);">LoopFlatten (mea culpa) needs a correctness fix, but other than that perhaps not
difficult to get enabled. Not sure if LoopReroll is just a benchmark special, but from a quick look that also needs a correctness fix. Interchange and UnrollAndJam would for example be really interesting to get on by default, but not sure if tricky cost modelling
business prevents that at the moment. LoopDistribute seems to be getting some TLC (D99596), and don't know much about the others.</span></div>
<div style="font-family: Calibri, Arial, Helvetica, sans-serif; font-size: 12pt; color: rgb(0, 0, 0);">
<span style="color: rgb(0, 0, 0); font-family: Calibri, Arial, Helvetica, sans-serif; font-size: 12pt; background: var(--white);"><br>
</span></div>
<div style="font-family: Calibri, Arial, Helvetica, sans-serif; font-size: 12pt; color: rgb(0, 0, 0);">
<span style="color: rgb(0, 0, 0); font-family: Calibri, Arial, Helvetica, sans-serif; font-size: 12pt; background: var(--white);">(Apologies if this has been discussed in the Loop Opt WG, I couldn't find anything after a quick look)</span></div>
</body>
</html>