[llvm] [LoopVectorize] Don't scalarize predicated instruction with optsize (PR #129265)

[David Sherwood via llvm-commits]

================
@@ -444,80 +283,24 @@ define void @example23b(ptr noalias nocapture %src, ptr noalias nocapture %dst)
   ret void
 }
 
-; We CAN vectorize this example by folding the tail it entails.
+; We CAN'T vectorize this example as it would require tail folding.
----------------
david-arm wrote:

Perhaps this should be:

```
; We CAN'T vectorize this example as it requires tail folding and
; would lead to significant increase in code size.
```

https://github.com/llvm/llvm-project/pull/129265