| Issue |
203027
|
| Summary |
Combine splice.right(splice.left(poison, x, offset), poison, offset) -> x
|
| Labels |
good first issue,
llvm:instcombine
|
| Assignees |
|
| Reporter |
lukel97
|
If we "slide" a vector to the left by offset elements, and then slide it right offset elements, we'll end up with a subset of the vector with some elements clipped off. If the splices use poison, then those elements are poison, and we can just simplify it back to x.
This is a transform we plan on doing in VPlan #199057. It may be useful for other users of the splice intrinsics to have it in InstCombine too.
As mentioned by @david-arm in https://github.com/llvm/llvm-project/pull/199057#discussion_r3389543420
![]()
_______________________________________________
llvm-bugs mailing list
[email protected]
https://lists.llvm.org/cgi-bin/mailman/listinfo/llvm-bugs
