[PATCH] D75885: [AArch64] Allow logical immediates to have all-1 in top bits

[Fangrui Song via Phabricator via llvm-commits]

MaskRay added a comment.

In D75885#1913963 <https://reviews.llvm.org/D75885#1913963>, @samparker wrote:

> It seems a bit odd to add assembly support for something which we also can't disassemble? It seems like a basic self-test that we should have.


Not odd. We can't assemble

  and w0, w0, #~(0xfe<<24)
  and w1, w1, #~(0xff<<24)

This patch teaches MC to assemble them. It is just that the disassembly is not a round trip.

For `dupm z0.h, #0x7f00`, it is indeed odd. GNU as behaves the same, though. I know too little about SVE to fix it properly by myself. I hope more experienced contributors can do that as a follow-up.


Repository:
  rG LLVM Github Monorepo

CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D75885/new/

https://reviews.llvm.org/D75885