[llvm] [LV]Enable max safe distance in predicated DataWithEVL vectorization mode. (PR #100755)

[Alexey Bataev via llvm-commits]

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@@ -1760,31 +1762,64 @@ bool MemoryDepChecker::couldPreventStoreLoadForward(uint64_t Distance,
   // cause any slowdowns.
   const uint64_t NumItersForStoreLoadThroughMemory = 8 * TypeByteSize;
   // Maximum vector factor.
-  uint64_t MaxVFWithoutSLForwardIssues = std::min(
-      VectorizerParams::MaxVectorWidth * TypeByteSize, MinDepDistBytes);
+  uint64_t MaxVFWithoutSLForwardIssuesPowerOf2 =
+      std::min(VectorizerParams::MaxVectorWidth * TypeByteSize,
+               MaxStoreLoadForwardSafeVF.first);
+  uint64_t MaxVFWithoutSLForwardIssuesNonPowerOf2 =
+      std::min(VectorizerParams::MaxVectorLMUL *
+                   VectorizerParams::MaxVectorWidth * TypeByteSize,
+               MaxStoreLoadForwardSafeVF.second);
 
   // Compute the smallest VF at which the store and load would be misaligned.
-  for (uint64_t VF = 2 * TypeByteSize; VF <= MaxVFWithoutSLForwardIssues;
-       VF *= 2) {
+  for (uint64_t VF = 2 * TypeByteSize;
+       VF <= MaxVFWithoutSLForwardIssuesPowerOf2; VF *= 2) {
     // If the number of vector iteration between the store and the load are
     // small we could incur conflicts.
     if (Distance % VF && Distance / VF < NumItersForStoreLoadThroughMemory) {
-      MaxVFWithoutSLForwardIssues = (VF >> 1);
+      MaxVFWithoutSLForwardIssuesPowerOf2 = (VF >> 1);
+      break;
+    }
+  }
+  // RISCV VLA supports non-power-2 vector factor. So, we iterate in a
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alexey-bataev wrote:

The initial patch with only power-of-2 support is committed already, this one adds non-power-of-2

https://github.com/llvm/llvm-project/pull/100755