[PATCH] D68408: [InstCombine] Negator - sink sinkable negations

[Sanjay Patel via Phabricator via llvm-commits]

spatel added a comment.

In D68408#1991910 <https://reviews.llvm.org/D68408#1991910>, @nikic wrote:

> Compile-time numbers look good: http://llvm-compile-time-tracker.com/compare.php?from=f52e0507574b4fd84dc4674536f5dfbab396c0f6&to=0a009b654793dee8e335c053eb043e297071e0d1&stat=instructions
>
> Change does not seem to have cost above noise, apart from a -0.6% improvement on tramp3d-v4. There's a corresponding -0.74% reducing in code-size, so this transform is clearly doing (or enabling) something big there. It might be interesting (but not necessary) to take a quick look at what happens there.


Yes, it would be good to derive a regression test from that benchmark and/or invent some larger tests that show the greater optimization power of the new code. Unless I missed it, all of the current test diffs show that we do no harm, but if we can show that the added code/complexity buys us something immediately, that makes the benefit clear.


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https://reviews.llvm.org/D68408