[PATCH] D146287: [AMDGPU][GISel] Add inverse ballot intrinsic

[Jessica Del via Phabricator via llvm-commits]

OutOfCache added inline comments.


================
Comment at: llvm/lib/Target/AMDGPU/SIISelLowering.cpp:4480
   }
+  case AMDGPU::S_INVERSE_BALLOT_U32:
+  case AMDGPU::S_INVERSE_BALLOT_U64: {
----------------
arsenm wrote:
> Why do you have to go through selecting the pseudo? Can't you do this split during the select?
I have attempted simply selecting the node to a copy, similar to the current GISel implementation. However, I have run into issues in case the mask is inside a VGPR. The following passes changed the VGPR->SGPR copy into a VGPR->VGPR copy instead of producing the v_readfirstlanes. Do you have any other suggestion of things I could try?


Repository:
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CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D146287/new/

https://reviews.llvm.org/D146287