arsenm wrote:

> Then %2 being used as the shift amount. We can't eliminate the zext/trunc 
> because the generic opcode has no mention of reading only the lower bits, 
> AFAIK.

We can fold the clamp of the shift amount into the shift instruction during 
selection as we know the instruction ignores the high bits. We do that in the 
DAG path already. I think it special cases the and & (bitwidth - 1) pattern, 
which should form canonically. In principle it could do a general simplify 
demand bits 

https://github.com/llvm/llvm-project/pull/131310
_______________________________________________
llvm-branch-commits mailing list
llvm-branch-commits@lists.llvm.org
https://lists.llvm.org/cgi-bin/mailman/listinfo/llvm-branch-commits

Reply via email to