[llvm] Expanding the Histogram Intrinsic (PR #127399)

[Paschalis Mpeis via llvm-commits]

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@@ -1239,10 +1240,10 @@ void VPHistogramRecipe::execute(VPTransformState &State) {
   // add a separate intrinsic in future, but for now we'll try this.
   if (Opcode == Instruction::Sub)
     IncAmt = Builder.CreateNeg(IncAmt);
-  else
-    assert(Opcode == Instruction::Add && "only add or sub supported for now");
+  assert(isLegalUpdateInstruction(UpdateInst) &&
+         "Found Ilegal update instruction for histogram");
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paschalis-mpeis wrote:

nit: typo also here, and a few other places: 
```suggestion
         "Found Illegal update instruction for histogram");
```

https://github.com/llvm/llvm-project/pull/127399