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<div class="moz-cite-prefix">On 5/11/20 10:53 PM, Chris Lattner
wrote:<br>
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<div class="">On May 8, 2020, at 4:40 PM, Josh Stone via
llvm-dev <<a href="mailto:llvm-dev@lists.llvm.org"
class="" moz-do-not-send="true">llvm-dev@lists.llvm.org</a>>
wrote:</div>
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<div class="moz-cite-prefix">On 4/14/20 1:26 AM, Neil
Henning via llvm-dev wrote:<br class="">
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<div class="">Hey list,</div>
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<div class="">TL;DR - LLVM 10 is around 7-8% slower
than LLVM 9 when compiling the same inputs.</div>
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[...] concerns from the Rust folks about LLVM 10's
slowdowns [...]<br class="">
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<p class="">I'm one of those Rust folks, and in the last
few days I've been trying to dig into this. I focused on
one particular benchmark input -- I've attached that IR
generated from Rust 1.43.0 for LLVM 9.0.1. I started
running a git bisection to see if anything huge jumped
out, but it seems to be gradual. Maybe others can take
my input and find some pattern to the decline.</p>
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<div>Hi Josh,</div>
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<div>On behalf of the “LLVM people”, I’d like to publicly thank
you for the this work to make sure that LLVM compile time
performance stays acceptable over time. I think that the Rust
community’s diligence in terms of tracking, improving, and
publicizing compile time performance has been incredibly
valuable. Thank you,</div>
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<p>Thank you, Chris, I'll certainly share that feedback with the
Rust community.</p>
<p>If there's anything specific I can do to make such data more
actionable, please let me know. I already learned from my Red Hat
peers that I didn't have a full understanding of llc vs opt etc.,
so I need to explore more to frame the test in a way that's closer
to what rustc actually does.<br>
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<p>Josh<br>
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