[llvm] [LV] Fix missing MetaData for histogram instructions (PR #134241)

[Florian Hahn via llvm-commits]

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@@ -8642,6 +8642,8 @@ VPRecipeBuilder::tryToWidenHistogram(const HistogramInfo *HI,
   HGramOps.push_back(Operands[1]);
   // Increment value.
   HGramOps.push_back(getVPValueOrAddLiveIn(HI->Update->getOperand(1)));
+  // Store Instruction.
+  HGramOps.push_back(getVPValueOrAddLiveIn(HI->Store));
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fhahn wrote:

Adding a live-in for the store as operand, just to get the underlying instruction to retrieve the metadata seems like a bit of a workaround.

I think it would be good to improve the existing metadata handling first and model it explicit in VPlan: https://github.com/llvm/llvm-project/pull/135272

Then it should be easy to preserve the metadata directly without needing any artificial operands

https://github.com/llvm/llvm-project/pull/134241