[release/7.0] Remove unnecessary runtime lookup for constrained callvirt #74523
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In my change adding support for default static virtual interface method implementations I made a subtle bug that caused behavioral change for some pre-existing constrained virtual calls that newly started to require runtime lookup. This is unnecessary and perf-negative, I have modified the code so that my change kicks in only for static virtual methods. Thanks Tomas
ghost
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Fixes: #73681 |
markples
approved these changes
Aug 25, 2022
jakobbotsch
approved these changes
Aug 25, 2022
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@jeffschwMSFT can we get an approval? @trylek can you confirm the CI failures are unrelated? BTW the dotnet-linker-tests leg seems to be stuck. |
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@carlossanlop - I don't see how the dotnet-linker-tests failure could be related to my change, I doubt the CoreCLR runtime was even running when the job got stuck, I retried the one failed job, I don't see any other failures in the testing. |
mangod9
approved these changes
Aug 25, 2022
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Approved and signed off. CI is green. Ready to merge. |
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Backport of #73823 to release/7.0
/cc @trylek
(This should really go into 7.0-RC1; based on @carlossanlop's e-mail I've made the backport against release/7.0 as the 7.0-rc1 branch is currently closed, please let me know how to proceed here.)
Customer Impact
According to #73681, this change fixes a user-visible C# behavior change and perf regression.
Testing
Local and lab testing in the runtime repo - innerloop, outerloop; Jakob manually verified on a code sample that the change fixes the codegen regression described in the issue.
Risk
Low - there's no real algorithmic change, the fix just modifies a conditional statement so that the logic I added for static virtual methods only truly applies to static virtual methods, previously it was "leaking" to non-static virtuals too, that was the cause of the codegen regression.
IMPORTANT: Is this backport for a servicing release? If so and this change touches code that ships in a NuGet package, please make certain that you have added any necessary package authoring and gotten it explicitly reviewed.