[llvm] [InstCombine] Split GEPs with multiple variable indices (PR #137297)

[Nikita Popov via llvm-commits]

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@@ -2777,6 +2777,12 @@ Instruction *InstCombinerImpl::visitGEPOfGEP(GetElementPtrInst &GEP,
     Indices.append(GEP.idx_begin()+1, GEP.idx_end());
   }
 
+  // Don't create GEPs with more than one variable index.
+  unsigned NumVarIndices =
+      count_if(Indices, [](Value *Idx) { return !isa<Constant>(Idx); });
+  if (NumVarIndices > 1)
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nikic wrote:

> Do you mean the call to `simplifyAddInst` above may produce a constant?

Yes, this is the motivation for the separate check.

https://github.com/llvm/llvm-project/pull/137297