Don't use IEnumerable and yield return for GetDefaultInterfaceImplementations

[jtschuster]

GetDefaultInterfaceImplementations takes the most time of anything in the linker in a hello world app, and allocates ~200mb total. If we refactor to not use yield return and directly add the DIMs to the cache in the method, we speed up by about 20% on a hello world app and use much less memory.

[ghost]

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Issue Details

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GetDefaultInterfaceImplementations takes the most time of anything in the linker in a hello world app, and allocates ~200mb total. If we refactor to not use yield return and directly add the DIMs in the method, we speed up by about 20% on a hello world app and use much less memory.

Author:	jtschuster
Assignees:	-
Labels:	linkable-framework
Milestone:	-

[sbomer]

Nice find, thanks!

[MichalStrehovsky]

This is not producing equivalent results.

Previously, we always called AddDefaultInterfaceImplementation (resolvedInterfaceMethod, type, {ThisComesFromTheAlgorithm});

Now we are calling AddDefaultInterfaceImplementation (resolvedInterfaceMethod, {ThisComesFromTheAlgorithm}, {ThisComesFromTheAlgorithm}); because at this spot type is swapped for potentialImplInterface when this recursively calls itself at this spot.

Is that a problem? Or the second parameter doesn't matter for anything? If it doesn't matter, the perf improvement in #98436 can be even better - we don't have to look for default implementation per each class - we can only look for default implementations when MapType is called for an interface and don't worry about default implementations when looking at classes at all.

[jtschuster]

Oh, good catch. We do need the correct 'ImplementingType' for this, so we'll have to make sure the original type is passed to AddDefaultInterfaceImplementation.