[PATCH] D69127: [DAGCombiner] widen zext of popcount based on target support

[Sanjay Patel via Phabricator via llvm-commits]

spatel added a comment.

In D69127#1715638 <https://reviews.llvm.org/D69127#1715638>, @RKSimon wrote:

> any_extend might get generated when using ctpop for 'allones' tests:
>
>   define i64 @var_ctpop_i32(i32 %a) {
>     %1 = call i32 @llvm.ctpop.i32(i32 %a)
>     %2 = zext i32 %1 to i64 ; SimplifyDemandedBits may turn zext (or sext) into aext
>     %3 = and i64 %2, 32
>     ret i64 %3
>   }
>   declare i32 @llvm.ctpop.i32(i32)
>


Thanks - I added a variant of this in:
rGb74d7e5cccb5 <https://reviews.llvm.org/rGb74d7e5cccb5eedb8675442a981a76f3873faf43> 
I'll add a TODO comment here and follow-up to generalize for that case.


CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D69127/new/

https://reviews.llvm.org/D69127