<html><head><style type='text/css'>p { margin: 0; }</style></head><body><div style='font-family: arial,helvetica,sans-serif; font-size: 10pt; color: #000000'><br><br><hr id="zwchr"><blockquote style="border-left: 2px solid rgb(16, 16, 255); margin-left: 5px; padding-left: 5px; color: rgb(0, 0, 0); font-weight: normal; font-style: normal; text-decoration: none; font-family: Helvetica,Arial,sans-serif; font-size: 12pt;"><b>From: </b>"Chandler Carruth" <chandlerc@gmail.com><br><b>To: </b>"Xinliang David Li" <davidxl@google.com><br><b>Cc: </b>"Mehdi Amini" <mehdi.amini@apple.com>, "Hal Finkel" <hfinkel@anl.gov>, "via llvm-dev" <llvm-dev@lists.llvm.org><br><b>Sent: </b>Monday, April 18, 2016 4:31:05 PM<br><b>Subject: </b>Re: [llvm-dev] Move InlineCost.cpp out of Analysis?<br><br><div dir="ltr"><div class="gmail_quote"><div dir="ltr">On Mon, Apr 18, 2016 at 2:28 PM Xinliang David Li <<a href="mailto:davidxl@google.com" target="_blank">davidxl@google.com</a>> wrote:<br></div><blockquote class="gmail_quote" style="margin: 0pt 0pt 0pt 0.8ex; border-left: 1px solid rgb(204, 204, 204); padding-left: 1ex;"><div dir="ltr"><div class="gmail_extra"><div class="gmail_quote">On Mon, Apr 18, 2016 at 2:18 PM, Chandler Carruth <span dir="ltr"><<a href="mailto:chandlerc@gmail.com" target="_blank">chandlerc@gmail.com</a>></span> wrote:<br><blockquote class="gmail_quote" style="margin: 0pt 0pt 0pt 0.8ex; border-left: 1px solid rgb(204, 204, 204); padding-left: 1ex;"><div dir="ltr">The difference between Analysis and Transforms is *not* about passes, but about what the code *does*.<div><br></div><div>Code for mutating the IR should be in Transforms, and code that analyzes the IR without mutating it should be in Analysis. This is why, for example, InstructionSimplify is in Analysis -- it does not mutate the IR in any way.</div><div><br></div><div>So I think InlineCost and similar things should stay in the Analysis library regardless of whether they are passes or not.</div></div></blockquote><div><br></div></div></div></div><div dir="ltr"><div class="gmail_extra"><div class="gmail_quote"><div>Is that the only criteria (IR mod or not) ?</div></div></div></div></blockquote><div><br></div><div>Given a public API, yes, that should be the only criteria IMO.</div><div> </div><blockquote class="gmail_quote" style="margin: 0pt 0pt 0pt 0.8ex; border-left: 1px solid rgb(204, 204, 204); padding-left: 1ex;"><div dir="ltr"><div class="gmail_extra"><div class="gmail_quote"><div> Most of the transformations have pass specific analysis (that are not shared with other clients) -- those code stay with the transformation -- it does not make sense to move those code in to Analysis.</div></div></div></div></blockquote><div><br></div><div id="DWT11839">But I would expect these to also not expose public APIs to the analyses. Provided the public API is limited to the transformation, I think the code be closely located makes sense.</div></div></div></blockquote>I'm not sure the situation is as clear cut as you make it out to be. We can factor common components out of different transformations (e.g. out of different inliner implementations), including common components that don't modify the IR, without that component forming what I would generally consider an analysis. In this case, we're really talking about the encapsulation of the inliner's cost heuristic, and the generality of this information is questionable. To put it another way, while I'm fine with someone reusing this logic to build a new inliner, I'd be very skeptical of using it for any other purpose. That's why it does not really feel like an analysis to me. This is not a strong feeling, however, and I'm also fine with it staying in Analysis.<br><br><blockquote style="border-left: 2px solid rgb(16, 16, 255); margin-left: 5px; padding-left: 5px; color: rgb(0, 0, 0); font-weight: normal; font-style: normal; text-decoration: none; font-family: Helvetica,Arial,sans-serif; font-size: 12pt;"><div dir="ltr"><div class="gmail_quote"><div></div><div> </div><blockquote class="gmail_quote" style="margin: 0pt 0pt 0pt 0.8ex; border-left: 1px solid rgb(204, 204, 204); padding-left: 1ex;"><div dir="ltr"><div class="gmail_extra"><div class="gmail_quote"><div> For the same reason, we need to ask first if InlineCost is intended to be a shared utility?</div></div></div></div></blockquote><div><br></div><div>Sure, but in fact at least some parts of it are shared.</div><div><br></div><div id="DWT11838">There is also some reason to prefer surfacing nice high-level public APIs when reasonable to do so. For example, if someone wanted to write a custom inlining pass that re-used the cost analysis, having it separated seems useful. So unless there is a significant problem solved by sinking this to be a private API only used by the inliner, I would keep it as-is.</div></div></div></blockquote>I did not take moving to Transforms/Utils to mean making the API private. The things in Transforms/Utils generally have public APIs.<br><br> -Hal<br><blockquote style="border-left: 2px solid rgb(16, 16, 255); margin-left: 5px; padding-left: 5px; color: rgb(0, 0, 0); font-weight: normal; font-style: normal; text-decoration: none; font-family: Helvetica,Arial,sans-serif; font-size: 12pt;"><div dir="ltr"><div class="gmail_quote"><div></div><div> </div><blockquote class="gmail_quote" style="margin: 0pt 0pt 0pt 0.8ex; border-left: 1px solid rgb(204, 204, 204); padding-left: 1ex;"><div dir="ltr"><div class="gmail_extra"><div class="gmail_quote"><div><br></div><div>David</div></div></div></div><div dir="ltr"><div class="gmail_extra"><div class="gmail_quote"><div><br></div><div> </div><blockquote class="gmail_quote" style="margin: 0pt 0pt 0pt 0.8ex; border-left: 1px solid rgb(204, 204, 204); padding-left: 1ex;"><div dir="ltr"><div><div><div><br><div class="gmail_quote"><div dir="ltr">On Mon, Apr 18, 2016 at 2:14 PM Mehdi Amini via llvm-dev <<a href="mailto:llvm-dev@lists.llvm.org" target="_blank">llvm-dev@lists.llvm.org</a>> wrote:<br></div><blockquote class="gmail_quote" style="margin: 0pt 0pt 0pt 0.8ex; border-left: 1px solid rgb(204, 204, 204); padding-left: 1ex;"><br>
> On Apr 18, 2016, at 2:07 PM, Hal Finkel via llvm-dev <<a href="mailto:llvm-dev@lists.llvm.org" target="_blank">llvm-dev@lists.llvm.org</a>> wrote:<br>
><br>
> <hr id="zwchr"><br>
>> From: "Easwaran Raman" <<a href="mailto:eraman@google.com" target="_blank">eraman@google.com</a>><br>
>> To: "via llvm-dev" <<a href="mailto:llvm-dev@lists.llvm.org" target="_blank">llvm-dev@lists.llvm.org</a>><br>
>> Cc: "Chandler Carruth" <<a href="mailto:chandlerc@gmail.com" target="_blank">chandlerc@gmail.com</a>>, "Hal Finkel" <<a href="mailto:hfinkel@anl.gov" target="_blank">hfinkel@anl.gov</a>>, "Philip Reames"<br>
>> <<a href="mailto:listmail@philipreames.com" target="_blank">listmail@philipreames.com</a>>, "David Li" <<a href="mailto:davidxl@google.com" target="_blank">davidxl@google.com</a>><br>
>> Sent: Monday, April 18, 2016 2:39:49 PM<br>
>> Subject: Move InlineCost.cpp out of Analysis?<br>
>><br>
>><br>
>> Hi,<br>
>><br>
>><br>
>> After r256521 - which removes InlineCostAnalysis class - I think<br>
>> there is no strong reason for InlineCost.cpp to be part of the<br>
>> Analysis library. Is it fine to make it part of TransformUtils?<br>
>><br>
><br>
> Given that InlineCost is not really an analysis any longer, I think this is fine.<br>
<br>
Isn't it? It is not a pass, but I see it as an analysis utils.<br>
<br>
><br>
>><br>
>> I submitted r266477 (which has now been reverted) that made Analysis<br>
>> depend on ProfileData in order to obtain ProfileSummary for the<br>
>> module, but there is an existing dependency of ProfileData on<br>
>> Analysis (through Object and BitCode).<br>
<br>
The real issue is that BitCode depends on Analysis I think.<br>
I'm not sure about ProfileData that depends on Bitcode, do you know why?<br>
<br>
--<br>
Mehdi<br>
<br>
<br>
>> Moving InlineCost.cpp under<br>
>> Transforms/Utils will fix this issue. There are other ways to fix<br>
>> this (make Inliner.cpp get the ProfileSummary and pass it to<br>
>> InlineCost, for example), but I think it makes sense to move<br>
>> InlineCost.<br>
>><br>
>><br>
>> Thoughts?<br>
>><br>
>><br>
>> Thanks,<br>
>> Easwaran<br>
>><br>
>><br>
><br>
> --<br>
> Hal Finkel<br>
> Assistant Computational Scientist<br>
> Leadership Computing Facility<br>
> Argonne National Laboratory<br>
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</blockquote></div></div></div></div></div>
</blockquote></div></div></div></blockquote></div></div>
</blockquote><br><br><br>-- <br><div><span name="x"></span>Hal Finkel<br>Assistant Computational Scientist<br>Leadership Computing Facility<br>Argonne National Laboratory<span name="x"></span><br></div></div></body></html>