[llvm] [LV] Vectorize histogram operations (PR #99851)

[Florian Hahn via llvm-commits]

================
@@ -4622,6 +4622,10 @@ bool LoopVectorizationPlanner::isCandidateForEpilogueVectorization(
   if (OrigLoop->getExitingBlock() != OrigLoop->getLoopLatch())
     return false;
 
+  // Loops containing histograms are not currently supported.
+  if (!Legal->getHistograms().empty())
+    return false;
+
----------------
fhahn wrote:

```suggestion
return Legal->getHistograms().empty()
```

https://github.com/llvm/llvm-project/pull/99851