[mlir][sparse] Add sparse rewriting rules for tensor::ReshapeOp

[anlunx]

Improve algorithm

[Peiming]

mlir/lib/Dialect/SparseTensor/Transforms/SparseTensorRewriting.cpp

389

Just think out loud, I somehow feel that you can reuse (or extend current collapse/expand_shape) here.

For example, extend reshapeCvs to take two reassociations, one for collapse and one for expand. collapse_shape/expand_shape only have one reassociation set, while reshape has both set. So that you can merge the three rewriters into similar implementation.

[aartbik]

mlir/lib/Dialect/SparseTensor/Transforms/SparseTensorRewriting.cpp

349

super nit, all rules here have a comment of the form

/// Sparse rewriting rule for the xxx operator.

that just describes the operator, but does not repeat the exact type found in the template following anyway

367

can't we combine this with L361, before we collect the sizes?
there is nothing dependent on that call, right?

375

an unordered

387

This block of code needs a leading comment that shows some pseudo-code on what construct is being generate
Also +1 on Peiming's feedback, it feels like you borrowed sufficient code from elsewhere that making small shared utils starts to make more sense

402

These comments really do not help much without a leading comment that describes what is happening

[anlunx]

Address comments

mlir/lib/Dialect/SparseTensor/Transforms/SparseTensorRewriting.cpp

367

Yes. It should be combined.

387

Added comment block

389

Used reshapeCvs twice to compute the destination coords

[anlunx]

rebase

[aartbik]

This looks good with the modifications. One last request, can you also add a CHECK test on the generated pattern. It does not have to test all the details, but at least the resulting loop structure to some extend?

mlir/test/Integration/Dialect/SparseTensor/CPU/sparse_reshape.mlir

18

do we really need to test (VLA) vectorization here too?

[anlunx]

Add a CHECK test

[anlunx]

mlir/test/Integration/Dialect/SparseTensor/CPU/sparse_reshape.mlir

18

Removed vectorization test

mlir/lib/Dialect/SparseTensor/Transforms/SparseTensorRewriting.cpp

 
 private:
   // Helper to add argument and record the mapping.
   static void addArg(IRMapping &mapper, Block *b, BlockArgument a) {
     mapper.map(a, b->addArgument(a.getType(), a.getLoc()));
   }
 };
 
 // Fuse a tensor cast into producing operation. Note that a tensor.cast
 // should really not be used to convert between sparse encodings. Since
 // the pattern currently appears as a result of some prior rewriting
 // we make an attempt to repair very obvious cases.
 // TODO: audit the pure tensor dialect rewriting rules
 struct FuseTensorCast : public OpRewritePattern<tensor::CastOp> {
 public:
   using OpRewritePattern<tensor::CastOp>::OpRewritePattern;
 
   LogicalResult matchAndRewrite(tensor::CastOp op,
                                 PatternRewriter &rewriter) const override {
     Type srcType = op.getSource().getType();
     Type dstType = op.getDest().getType();
     // A nop cast simply folds away.
     if (srcType == dstType) {
       rewriter.replaceOp(op, op->getResults());
       return success();
     }
     // See if a sparsity changing cast can be fused into producer.
     if (tensor::isSameTypeWithoutEncoding(srcType, dstType)) {
       if (Operation *def = op.getSource().getDefiningOp()) {
         if (def->hasOneUse() && isa<tensor::ExtractSliceOp>(def)) {
           def->getResult(0).setType(op->getResultTypes()[0]);
           rewriter.replaceOp(op, def->getResult(0));
           return success();
         }
       }
     }
     // Repair tensor casts with at least one sparse operand into the
     // the properly supported sparse_tensor.convert.
     if (getSparseTensorEncoding(srcType) || getSparseTensorEncoding(dstType)) {
       rewriter.replaceOpWithNewOp<ConvertOp>(op, dstType, op.getSource());
       return success();
     }
     // Fail otherwise.
     return failure();
   }
 };
 
 /// Sparse rewriting rule for sparse-to-sparse reshape operator.
+struct TensorReshapeRewriter : public OpRewritePattern<tensor::ReshapeOp> {
+public:
+  using OpRewritePattern<tensor::ReshapeOp>::OpRewritePattern;
+
+  LogicalResult matchAndRewrite(tensor::ReshapeOp op,
+                                PatternRewriter &rewriter) const override {
+    Location loc = op.getLoc();
+    Value srcTensor = op.getSource();
+    const auto srcTp = getSparseTensorType(srcTensor);
+    const auto dstTp = getSparseTensorType(op.getResult());
+
+    if (!srcTp.hasEncoding() || !dstTp.hasEncoding() ||
+        !dstTp.hasStaticDimShape())
+      return failure();
+
+    SmallVector<Value> srcSizes;
+    sizesForTensor(rewriter, srcSizes, loc, srcTp, srcTensor);
+    SmallVector<Value> dstSizes;
+    for (Dimension d : dstTp.getDimShape())
+      dstSizes.push_back(constantIndex(rewriter, loc, d));
+
+    Value nnz = rewriter.create<NumberOfEntriesOp>(loc, srcTensor);
+    // Only need an unordered COO buffer if input and output are not sorted
+    // in the same way.
+    Type bufferTp =
+        srcTp.isAllOrdered() && srcTp.isIdentity() && dstTp.isIdentity()
+            ? dstTp.getRankedTensorType()
+            : getUnorderedCOOFromType(dstTp);
+    SmallVector<Value> dynSizes;
+    Value buffer = rewriter
+                       .create<AllocTensorOp>(loc, bufferTp, dynSizes, Value(),
+                                              nnz, Attribute())
+                       .getResult();
+
+    // Convert src coordinates to dst coordinates by first collapsing it to 1D
+    // and then expand it to the match the rank of the destination tensor.
+    // Implemented as follows:
+    //   foreach srcCoords %srcTensor
+    //     collapsedCoords = reshapeCvs(srcCoords, [1, ..., srcRank])
+    //     expandedCoords = reshapeCvs(collapsedCoords, [1, ..., dstRank])
+    //     insert expandedCoords, %buffer
+    //
+    // followed by an optional
+    //   %t = sparse_tensor.cast %tmp
+    // depending on whether the input/output are sorted in the same way.
+    const auto encSrc = srcTp.getEncoding();
+    ForeachOp foreachOp = rewriter.create<ForeachOp>(
+        loc, srcTensor, buffer,
+        [&](OpBuilder &builder, Location loc, ValueRange srcLcvs, Value v,
+            ValueRange reduc) {
+          const Dimension srcRank = srcTp.getDimRank();
+          SmallVector<Value> srcDcvs;
+          srcDcvs.reserve(srcRank);
+          for (Dimension d = 0; d < srcRank; d++) {
+            // FIXME: `toStoredDim` is deprecated
+            Level lvl = toStoredDim(encSrc, d);
+            srcDcvs.push_back(srcLcvs[lvl]);
+          }
+
+          Value collapsed_size = constantIndex(builder, loc, 1);
+          for (Dimension d = 0; d < srcRank; d++)
+            collapsed_size =
+                builder.create<arith::MulIOp>(loc, collapsed_size, srcSizes[d]);
+          SmallVector<Value, 1> collapsedSizes = {collapsed_size};
+
+          ReassociationIndices collapse_indices;
+          for (Dimension i = 0; i < srcRank; i++)
+            collapse_indices.push_back(i);
+          SmallVector<ReassociationIndices, 1> collapse_reassociation = {
+              collapse_indices};
+          SmallVector<Value, 1> collapsedDcvs;
+          reshapeCvs(builder, loc, collapse_reassociation, srcSizes, srcDcvs,
+                     collapsedSizes, collapsedDcvs);
+
+          ReassociationIndices expand_indices;
+          for (Dimension i = 0; i < dstTp.getDimRank(); i++)
+            expand_indices.push_back(i);
+          SmallVector<ReassociationIndices, 1> expand_reassociation = {
+              expand_indices};
+          SmallVector<Value> dstDcvs;
+          reshapeCvs(builder, loc, expand_reassociation, collapsedSizes,
+                     collapsedDcvs, dstSizes, dstDcvs);
+
+          auto t = builder.create<InsertOp>(loc, v, reduc.front(), dstDcvs);
+          builder.create<sparse_tensor::YieldOp>(loc, t);
+        });
+
+    Value t = rewriter.create<LoadOp>(loc, foreachOp.getResult(0), true);
+    if (bufferTp != dstTp) {
+      auto dstRTT = dstTp.getRankedTensorType();
+      Value converted = rewriter.create<ConvertOp>(loc, dstRTT, t).getResult();
+      rewriter.create<DeallocTensorOp>(loc, t);
+      t = converted;
+    }
+    rewriter.replaceOp(op, t);
+    return success();
+  }
+};
+
+/// Sparse rewriting rule for sparse-to-sparse reshape operator.
 template <typename ReshapeOp>
 struct Sparse2SparseReshapeRewriter : public OpRewritePattern<ReshapeOp> {
 public:
   using OpRewritePattern<ReshapeOp>::OpRewritePattern;
 
   LogicalResult matchAndRewrite(ReshapeOp op,
                                 PatternRewriter &rewriter) const override {
     Location loc = op.getLoc();
patterns.add<FoldInvariantYield, FuseSparseMultiplyOverAdd, FuseTensorCast>(
       patterns.getContext());
 }
 
 void mlir::populatePostSparsificationRewriting(RewritePatternSet &patterns,
                                                bool enableRT,
                                                bool enableForeach,
                                                bool enableConvert) {
   patterns.add<ReshapeRewriter<tensor::ExpandShapeOp>,
-               ReshapeRewriter<tensor::CollapseShapeOp>>(patterns.getContext());
+               ReshapeRewriter<tensor::CollapseShapeOp>, TensorReshapeRewriter>(
+      patterns.getContext());
   if (enableForeach)
     patterns.add<ForeachRewriter>(patterns.getContext());
   // TODO: If RT not enabled, rewrite concatenate ops, etc here.
   if (!enableRT) {
     patterns.add<ConcatenateRewriter, NewRewriter, OutRewriter,
                  Sparse2SparseReshapeRewriter<tensor::ExpandShapeOp>,
                  Sparse2SparseReshapeRewriter<tensor::CollapseShapeOp>>(
         patterns.getContext());
     if (enableConvert)
       patterns.add<ConvertRewriter>(patterns.getContext());
   }
 }

mlir/test/Integration/Dialect/SparseTensor/CPU/sparse_reshape.mlir

+// DEFINE: %{option} = enable-runtime-library=true
+// DEFINE: %{compile} = mlir-opt %s --sparse-compiler=%{option}
+// DEFINE: %{run} = mlir-cpu-runner \
+// DEFINE:  -e entry -entry-point-result=void  \
+// DEFINE:  -shared-libs=%mlir_c_runner_utils | \
+// DEFINE: FileCheck %s
+//
+// RUN: %{compile} | %{run}
+//
+// Do the same run, but now with direct IR generation.
+// REDEFINE: %{option} = enable-runtime-library=false
+// RUN: %{compile} | %{run}
+//
+// Do the same run, but now with direct IR generation and vectorization.
+// REDEFINE: %{option} = "enable-runtime-library=false vl=2 reassociate-fp-reductions=true enable-index-optimizations=true"
+// RUN: %{compile} | %{run}
+
+// Do the same run, but now with direct IR generation and, if available, VLA
+// vectorization.
+// REDEFINE: %{option} = "enable-runtime-library=false vl=4 enable-arm-sve=%ENABLE_VLA"
+// REDEFINE: %{run} = %lli_host_or_aarch64_cmd \
+// REDEFINE:   --entry-function=entry_lli \
+// REDEFINE:   --extra-module=%S/Inputs/main_for_lli.ll \
+// REDEFINE:   %VLA_ARCH_ATTR_OPTIONS \
+// REDEFINE:   --dlopen=%mlir_native_utils_lib_dir/libmlir_c_runner_utils%shlibext | \
+// REDEFINE: FileCheck %s
+// RUN: %{compile} | mlir-translate -mlir-to-llvmir | %{run}
+
+#SparseVector = #sparse_tensor.encoding<{
+  dimLevelType = ["compressed"]
+}>
+
+#SparseMatrix = #sparse_tensor.encoding<{
+  dimLevelType = ["compressed", "compressed"]
+}>
+
+#Sparse3dTensor = #sparse_tensor.encoding<{
+  dimLevelType = ["compressed", "compressed", "compressed"]
+}>
+
+module {
+
+  func.func @reshape0(%arg0: tensor<3x4xf64, #SparseMatrix>) -> tensor<2x6xf64, #SparseMatrix> {
+    %shape = arith.constant dense <[ 2, 6 ]> : tensor<2xi32>
+    %0 = tensor.reshape %arg0(%shape) : (tensor<3x4xf64, #SparseMatrix>, tensor<2xi32>) -> tensor<2x6xf64, #SparseMatrix>
+    return %0 : tensor<2x6xf64, #SparseMatrix>
+  }
+
+  func.func @reshape1(%arg0: tensor<3x4xf64, #SparseMatrix>) -> tensor<12xf64, #SparseVector> {
+    %shape = arith.constant dense <[ 12 ]> : tensor<1xi32>
+    %0 = tensor.reshape %arg0(%shape) : (tensor<3x4xf64, #SparseMatrix>, tensor<1xi32>) -> tensor<12xf64, #SparseVector>
+    return %0 : tensor<12xf64, #SparseVector>
+  }
+
+  func.func @reshape2(%arg0: tensor<3x4xf64, #SparseMatrix>) -> tensor<2x3x2xf64, #Sparse3dTensor> {
+    %shape = arith.constant dense <[ 2, 3, 2 ]> : tensor<3xi32>
+    %0 = tensor.reshape %arg0(%shape) : (tensor<3x4xf64, #SparseMatrix>, tensor<3xi32>) -> tensor<2x3x2xf64, #Sparse3dTensor>
+    return %0 : tensor<2x3x2xf64, #Sparse3dTensor>
+  }
+
+
+  func.func @entry() {
+    %m = arith.constant dense <[ [ 1.1,  0.0,  1.3,  0.0 ],
+                                 [ 2.1,  0.0,  2.3,  0.0 ],
+                                 [ 3.1,  0.0,  3.3,  0.0 ]]> : tensor<3x4xf64>
+    %sm = sparse_tensor.convert %m : tensor<3x4xf64> to tensor<3x4xf64, #SparseMatrix>
+
+    %reshaped0 = call @reshape0(%sm) : (tensor<3x4xf64, #SparseMatrix>) -> tensor<2x6xf64, #SparseMatrix>
+    %reshaped1 = call @reshape1(%sm) : (tensor<3x4xf64, #SparseMatrix>) -> tensor<12xf64, #SparseVector>
+    %reshaped2 = call @reshape2(%sm) : (tensor<3x4xf64, #SparseMatrix>) -> tensor<2x3x2xf64, #Sparse3dTensor>
+
+    %c0 = arith.constant 0 : index
+    %df = arith.constant -1.0 : f64
+
+    // CHECK: ( 1.1, 1.3, 2.1, 2.3, 3.1, 3.3
+    %b0 = sparse_tensor.values %reshaped0: tensor<2x6xf64, #SparseMatrix> to memref<?xf64>
+    %v0 = vector.transfer_read %b0[%c0], %df: memref<?xf64>, vector<12xf64>
+    vector.print %v0 : vector<12xf64>
+
+    // CHECK: ( 1.1, 1.3, 2.1, 2.3, 3.1, 3.3
+    %b1 = sparse_tensor.values %reshaped1: tensor<12xf64, #SparseVector> to memref<?xf64>
+    %v1 = vector.transfer_read %b1[%c0], %df: memref<?xf64>, vector<12xf64>
+    vector.print %v1 : vector<12xf64>
+
+    // CHECK: ( 1.1, 1.3, 2.1, 2.3, 3.1, 3.3
+    %b2 = sparse_tensor.values %reshaped2: tensor<2x3x2xf64, #Sparse3dTensor> to memref<?xf64>
+    %v2 = vector.transfer_read %b2[%c0], %df: memref<?xf64>, vector<12xf64>
+    vector.print %v2: vector<12xf64>
+
+    bufferization.dealloc_tensor %sm : tensor<3x4xf64, #SparseMatrix>
+    bufferization.dealloc_tensor %reshaped0 : tensor<2x6xf64, #SparseMatrix>
+    bufferization.dealloc_tensor %reshaped1 : tensor<12xf64, #SparseVector>
+    bufferization.dealloc_tensor %reshaped2 : tensor<2x3x2xf64, #Sparse3dTensor>
+
+    return
+  }
+
+}
 No newline at end of file