Lower BinOp::Cmp to llvm.{s,u}cmp.* intrinsics #133984
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LLVM 19 doesn't have all the optimization support for these intrinsics yet. |
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Should the check be on LLVM 20? |
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Lowers `mir::BinOp::Cmp` (`three_way_compare` intrinsic) to the corresponding
LLVM `llvm.{s,u}cmp.i8.*` intrinsics, added in LLVM 19.
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I'm excited to do this, but if nikic says it's too early, that probably means it shouldn't be on by default yet. Maybe make this PR adding a -Z flag for it, so people can play with it and test out how close it is? (Then in the future once it's fully ready we can remove that flag again) |
Yes, that's fine. You'll have to test locally against LLVM 20 though to make sure codegen tests don't break. |
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Lowers
mir::BinOp::Cmp(three_way_compareintrinsic) to the corresponding LLVMllvm.{s,u}cmp.i8.*intrinsics.These are the intrinsics mentioned in #118310, which are now available in LLVM 19.
I couldn't find any follow-up PRs/discussions about this, please let me know if I missed something.
r? @scottmcm