[PATCH] D127158: [AArch64] Add intrinsic support for gpr<->fpr flavors of fixed-point converts

[Rob McClure via Phabricator via llvm-commits]

rmcclure added a comment.

One of the existing tests (do_stuff in CodeGen/AArch64/arm64-fixed-point-scalar-cvt-dagcombine.ll) fails with this change, because we now generate an fmov followed by a gpr->fpr ucvtf, instead of the expected fpr->fpr ucvtf. Of course, other tests show that we now avoid an unnecessary fmov after this change.
Is there a preferred method for making a better decision for when to use the gpr->fpr or fpr->fpr flavor of these instructions?
I see the AArch64AdvSIMDScalarPass pass which converts certain GPR ops into AdvSIMD scalar ops when it would save on copies, which sounds mildly similar to the problem I'd like to solve here. Would it be reasonable to leverage that pass for this purpose?


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  https://reviews.llvm.org/D127158/new/

https://reviews.llvm.org/D127158