[llvm] [LV]Initial support for safe distance in predicated DataWithEVL vectorization mode. (PR #102897)

[Alexey Bataev via llvm-commits]

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@@ -3903,9 +3919,14 @@ FixedScalableVFPair LoopVectorizationCostModel::computeFeasibleMaxVF(
   // dependence distance).
   unsigned MaxSafeElements =
       llvm::bit_floor(Legal->getMaxSafeVectorWidthInBits() / WidestType);
+  unsigned MaxScalableSafeElements = MaxSafeElements;
+  if (foldTailWithEVL() && !Legal->isSafeForAnyVectorWidth()) {
+    MaxScalableSafeElements = std::numeric_limits<unsigned>::max();
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alexey-bataev wrote:

I thought about this and at first I thought it might be good to use max here. But after some thoughts, I think next-power-of-2 is good here

https://github.com/llvm/llvm-project/pull/102897