[llvm] [SLP] Initial vectorization of non-power-of-2 ops. (PR #77790)

[Alexey Bataev via llvm-commits]

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@@ -14036,10 +14084,22 @@ bool SLPVectorizerPass::vectorizeStores(ArrayRef<StoreInst *> Stores,
 
       unsigned Sz = 1 + Log2_32(MaxVF) - Log2_32(MinVF);
       SmallVector<unsigned> CandidateVFs(Sz);
+      auto VFsToFill = make_range(CandidateVFs.begin(), CandidateVFs.end());
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alexey-bataev wrote:

Something like 
```
SmallVector<unsigned> CandidateVFs(Sz+(non-power-of-2-vf ? 1 : 0));
unsigned Size = MinVF;
for_each(reverse(CandidateVFs), [&](unsigned &VF) {
        VF = Size > MaxVF ? non-power-of-2-vf : Size;
        Size *= 2;
      });
```
?

https://github.com/llvm/llvm-project/pull/77790