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

[Min-Yih Hsu via llvm-commits]

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@@ -3377,34 +3441,45 @@ 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) {
-        // Deinterleave the elements within the vector
-        SmallVector<Value *> TempDeinterleavedValues(NumVectors);
-        for (unsigned I = 0; I < NumVectors; ++I) {
-          auto *DiTy = DeinterleavedValues[I]->getType();
-          TempDeinterleavedValues[I] = State.Builder.CreateIntrinsic(
-              Intrinsic::vector_deinterleave2, DiTy, DeinterleavedValues[I],
-              /*FMFSource=*/nullptr, "strided.vec");
+
+      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 {
+        assert(isPowerOf2_32(InterleaveFactor) &&
+               "Unsupported deinterleave factor for scalable vectors");
+        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) {
+          // Deinterleave the elements within the vector
+          SmallVector<Value *> TempDeinterleavedValues(NumVectors);
----------------
mshockwave wrote:

could we declare `TempDeinterleavedValues` with a size of InterleaveFactor outside the NumVectors loop? We don't even need to clear it before going into the `I` loop because we always override the values we're gonna use in the ExtractValue loop.

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