[llvm] [LV] Support scalable interleave groups for factors 3, 5, 6 and 7 (PR #141865)

[Florian Hahn via llvm-commits]

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@@ -3438,34 +3446,44 @@ void VPInterleaveRecipe::execute(VPTransformState &State) {
     ArrayRef<VPValue *> VPDefs = definedValues();
     const DataLayout &DL = State.CFG.PrevBB->getDataLayout();
     if (VecTy->isScalableTy()) {
-      assert(isPowerOf2_32(InterleaveFactor) &&
-             "Unsupported deinterleave factor for scalable vectors");
-
       // Scalable vectors cannot use arbitrary shufflevectors (only splats),
       // so must use intrinsics to deinterleave.
       SmallVector<Value *> DeinterleavedValues(InterleaveFactor);
-      DeinterleavedValues[0] = NewLoad;
-      // For the case of InterleaveFactor > 2, we will have to do recursive
-      // deinterleaving, because the current available deinterleave intrinsic
-      // supports only Factor of 2, otherwise it will bailout after first
-      // iteration.
-      // When deinterleaving, the number of values will double until we
-      // have "InterleaveFactor".
-      for (unsigned NumVectors = 1; NumVectors < InterleaveFactor;
-           NumVectors *= 2) {
+
+      if (InterleaveFactor <= 8) {
+        Value *Deinterleave = State.Builder.CreateIntrinsic(
+            getDeinterleaveIntrinsicID(InterleaveFactor), NewLoad->getType(),
+            NewLoad,
+            /*FMFSource=*/nullptr, "strided.vec");
+        for (unsigned I = 0; I < InterleaveFactor; I++)
+          DeinterleavedValues[I] =
+              State.Builder.CreateExtractValue(Deinterleave, I);
+      } else {
+        // TODO: No in-tree target will reach this case. Should this be removed?
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fhahn wrote:

Sounds right

https://github.com/llvm/llvm-project/pull/141865