[PATCH] D79452: [VectorCombine] scalarize binop of inserted elements into undef

[Simon Pilgrim via Phabricator via llvm-commits]

RKSimon added inline comments.


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Comment at: llvm/lib/Transforms/Vectorize/VectorCombine.cpp:320
+  Value *V0, *V1;
+  uint64_t Index;
+  if (!match(Ins0, m_OneUse(m_InsertElement(m_Undef(), m_Value(V0),
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lebedev.ri wrote:
> Hm, do we have an interface to ask for cost of `InsertElement` with variable insert index?
Yes we set Index to -1 in the getVectorInstrCost call if its unknown/variable - we don't do much with it in x86 at least though........


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https://reviews.llvm.org/D79452