[llvm] [SDAG] Add CTTZ_ELTS[_ZERO_POISON] nodes. NFCI (PR #185600)

[Luke Lau via llvm-commits]

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@@ -171,6 +171,23 @@ define i64 @i64_ctz_nxv16i1(<vscale x 16 x i1> %pg, <vscale x 16 x i1> %a) {
   ret i64 %res
 }
 
+define i64 @i64_ctz_nxv16i1_range(<vscale x 16 x i1> %pg, <vscale x 16 x i1> %a) vscale_range(2, 1024) {
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lukel97 wrote:

Exercises the path for ExpandIntegerResult when the vscale range doesn't wrap, and half of the result type bits is known to fit.

https://github.com/llvm/llvm-project/pull/185600