[Mlir-commits] [mlir] [mlir][vector] Add 1D vector.deinterleave lowering (PR #93042)

[Cullen Rhodes]

================
@@ -1761,6 +1761,70 @@ struct VectorInterleaveOpLowering
   }
 };
 
+/// Conversion pattern for a `vector.deinterleave`.
+/// This supports for fixed-sized vectors and scalable vectors.
+struct VectorDeinterleaveOpLowering
+    : public ConvertOpToLLVMPattern<vector::DeinterleaveOp> {
+  using ConvertOpToLLVMPattern::ConvertOpToLLVMPattern;
+
+  LogicalResult
+  matchAndRewrite(vector::DeinterleaveOp deinterleaveOp, OpAdaptor adaptor,
+                  ConversionPatternRewriter &rewriter) const override {
+    VectorType resultType = deinterleaveOp.getResultVectorType();
+    VectorType sourceType = deinterleaveOp.getSourceVectorType();
+    auto loc = deinterleaveOp.getLoc();
+
+    // Note: n-D deinterleave operations should be lowered to the 1-D before
+    // converting to LLVM.
+    if (resultType.getRank() != 1)
+      return rewriter.notifyMatchFailure(deinterleaveOp,
+                                         "DeinterleaveOp not rank 1");
+
+    if (resultType.isScalable()) {
+      auto llvmTypeConverter = this->getTypeConverter();
+      auto deinterleaveResults = deinterleaveOp.getResultTypes();
+      auto packedOpResults =
+          llvmTypeConverter->packOperationResults(deinterleaveResults);
+      auto intrinsic = rewriter.create<LLVM::vector_deinterleave2>(
+          loc, packedOpResults, adaptor.getSource());
+
+      auto evenResult = rewriter.create<LLVM::ExtractValueOp>(
+          loc, intrinsic->getResult(0), 0);
+      auto oddResult = rewriter.create<LLVM::ExtractValueOp>(
+          loc, intrinsic->getResult(0), 1);
+
+      rewriter.replaceOp(deinterleaveOp, ValueRange{evenResult, oddResult});
+      return success();
+    }
+    // Lower fixed-size deinterleave to two shufflevectors. While the
+    // vector.deinterleave2 intrinsic supports fixed and scalable vectors, the
+    // langref still recommends fixed-vectors use shufflevector, see:
+    // https://llvm.org/docs/LangRef.html#id889.
+    int64_t resultVectorSize = resultType.getNumElements();
+    SmallVector<int32_t> evenShuffleMask;
+    SmallVector<int32_t> oddShuffleMask;
+
+    evenShuffleMask.reserve(resultVectorSize);
+    oddShuffleMask.reserve(resultVectorSize);
----------------
c-rhodes wrote:

this should be half width?
```suggestion
    evenShuffleMask.reserve(resultVectorSize / 2);
    oddShuffleMask.reserve(resultVectorSize / 2);
```

https://github.com/llvm/llvm-project/pull/93042