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[NFC][FuncAttrs] Add comment on why we look for noreturn calls
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Authored by aeubanks on Jan 7 2021, 11:01 AM.

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aeubanks created this revision.Jan 7 2021, 11:01 AM
aeubanks requested review of this revision.Jan 7 2021, 11:01 AM
Herald added a project: Restricted Project. · View Herald TranscriptJan 7 2021, 11:01 AM

I'm dropping my request which triggered this review. Feel free to close.

Why? Because I went and looked into this further, and neither the old nor new pass manager actually handle this in a sane way. With the recent changes, they both handle it in approximately the same insane way.

Both have a nice bottom up traversal of the call graph. You think we'd simplify the SCC, then infer properties, than move to the caller SCC and exploit them right? Well, no. We infer, then simplify, then go to the caller. The result is that we don't get to benefit from any of the simplification when doing the analysis.

aeubanks abandoned this revision.Jan 11 2021, 8:28 AM