[PATCH] D76122: [ARM,MVE] Add intrinsics and isel for MVE integer VMLA.

[Simon Tatham via Phabricator via cfe-commits]

simon_tatham marked an inline comment as done.
simon_tatham added inline comments.


================
Comment at: llvm/lib/Target/ARM/ARMISelLowering.cpp:14289-14292
   case Intrinsic::arm_neon_vqrshifts:
   case Intrinsic::arm_neon_vqrshiftu:
     // No immediate versions of these to check for.
     break;
----------------
dmgreen wrote:
> I know it's not part of this patch, but what is this code for?
I have no idea! They date from rG2e076c4e02fb99 in 2009 which first introduced NEON support, and even then, the switch they appear in had a `default: break` clause.

My best guess is that they're intended as a kind of documentation. They signal to the reader: "I didn't //forget// about these intrinsics, I carefully considered them, decided they didn't need handling here, and included a comment saying why not."


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  https://reviews.llvm.org/D76122/new/

https://reviews.llvm.org/D76122