[llvm] [LV][EVL] Peek through combination tail-folded + predicated masks (PR #133430)

[Florian Hahn via llvm-commits]

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@@ -1764,6 +1764,10 @@ static VPRecipeBase *createEVLRecipe(VPValue *HeaderMask,
   using namespace llvm::VPlanPatternMatch;
   auto GetNewMask = [&](VPValue *OrigMask) -> VPValue * {
     assert(OrigMask && "Unmasked recipe when folding tail");
+    using namespace llvm::VPlanPatternMatch;
+    VPValue *Mask;
+    if (match(OrigMask, m_LogicalAnd(m_Specific(HeaderMask), m_VPValue(Mask))))
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fhahn wrote:

might be good to add a quick comment with an explantation., e.g. something like
```suggestion
    // HeaderMask will be handled using EVL.
    if (match(OrigMask, m_LogicalAnd(m_Specific(HeaderMask), m_VPValue(Mask))))
```

https://github.com/llvm/llvm-project/pull/133430