[PATCH] D141135: [RFC][GlobalISel] Replace the current GlobalISel matcher with a bottom-up matcher

[Amara Emerson via Phabricator via llvm-commits]

aemerson added a comment.

In D141135#4036756 <https://reviews.llvm.org/D141135#4036756>, @Kai wrote:

> - Visit of changed instructions in the Combiner is now done iteratively.
> - The array with the rules to execute in the generated source is a bit more compact.
>
> Running LLVM test suite with `-fglobal-isel` on an AArch64 EC2 instance (2 CPUs, 4GB):
> Current implementation:  22m43.224s
> Bottom-up implementation: 22m47.165s
>
> Size of the binaries:
> Current implementation: llc 127.280.024, clang 217.540.416
> Bottom-up implementation: llc 127.026.960, clang 217.291.456

I haven't had time to properly look at the implementation, but a question on this. When you say "running the test suite", are you talking about building the test suite with -fglobal-isel? Not running the generated code right?

Secondly, you mentioned that this is a drop on replacement for the existing matcher, yet we're seeing some code size differences. Do you know why?


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