Files
clang-p2996/mlir/lib/Dialect/SparseTensor/Transforms/SparseTensorConversion.cpp
Matthias Springer c0a6318d96 [mlir][tensor] Add tensor.dim operation
* Split memref.dim into two operations: memref.dim and tensor.dim. Both ops have the same builder interface and op argument names, so that they can be used with templates in patterns that apply to both tensors and memrefs (e.g., some patterns in Linalg).
* Add constant materializer to TensorDialect (needed for folding in affine.apply etc.).
* Remove some MemRefDialect dependencies, make some explicit.

Differential Revision: https://reviews.llvm.org/D105165
2021-07-01 10:00:19 +09:00

315 lines
11 KiB
C++

//===- SparseTensorLowering.cpp - Sparse tensor primitives conversion -----===//
//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
//
//===----------------------------------------------------------------------===//
//
// Convert sparse tensor primitives to calls into a runtime support library.
// Note that this is a current implementation choice to keep the conversion
// simple. In principle, these primitives could also be converted to actual
// elaborate IR code that implements the primitives on the selected sparse
// tensor storage schemes.
//
//===----------------------------------------------------------------------===//
#include "mlir/Dialect/LLVMIR/LLVMTypes.h"
#include "mlir/Dialect/MemRef/IR/MemRef.h"
#include "mlir/Dialect/SparseTensor/IR/SparseTensor.h"
#include "mlir/Dialect/SparseTensor/Transforms/Passes.h"
#include "mlir/Dialect/StandardOps/IR/Ops.h"
#include "mlir/Dialect/Tensor/IR/Tensor.h"
#include "mlir/Transforms/DialectConversion.h"
using namespace mlir;
using namespace mlir::sparse_tensor;
namespace {
/// Returns internal type encoding for overhead storage.
static unsigned getOverheadTypeEncoding(unsigned width) {
switch (width) {
default:
return 1;
case 32:
return 2;
case 16:
return 3;
case 8:
return 4;
}
}
/// Returns internal dimension level type encoding.
static unsigned
getDimLevelTypeEncoding(SparseTensorEncodingAttr::DimLevelType dlt) {
switch (dlt) {
case SparseTensorEncodingAttr::DimLevelType::Dense:
return 0;
case SparseTensorEncodingAttr::DimLevelType::Compressed:
return 1;
case SparseTensorEncodingAttr::DimLevelType::Singleton:
return 2;
}
llvm_unreachable("Unknown SparseTensorEncodingAttr::DimLevelType");
}
/// Returns integers of given width and values as a constant tensor.
/// We cast the static shape into a dynamic shape to ensure that the
/// method signature remains uniform accross different tensor dimensions.
static Value getTensor(ConversionPatternRewriter &rewriter, unsigned width,
Location loc, ArrayRef<APInt> values) {
Type etp = rewriter.getIntegerType(width);
unsigned sz = values.size();
RankedTensorType tt1 = RankedTensorType::get({sz}, etp);
RankedTensorType tt2 = RankedTensorType::get({ShapedType::kDynamicSize}, etp);
auto elts =
rewriter.create<ConstantOp>(loc, DenseElementsAttr::get(tt1, values));
return rewriter.create<tensor::CastOp>(loc, tt2, elts);
}
/// Returns function reference (first hit also inserts into module).
static FlatSymbolRefAttr getFunc(Operation *op, StringRef name, Type result,
ValueRange operands) {
MLIRContext *context = op->getContext();
auto module = op->getParentOfType<ModuleOp>();
auto func = module.lookupSymbol<FuncOp>(name);
if (!func) {
OpBuilder moduleBuilder(module.getBodyRegion());
moduleBuilder
.create<FuncOp>(op->getLoc(), name,
FunctionType::get(context, operands.getTypes(), result))
.setPrivate();
}
return SymbolRefAttr::get(context, name);
}
/// Sparse conversion rule for returns.
class SparseReturnConverter : public OpConversionPattern<ReturnOp> {
public:
using OpConversionPattern::OpConversionPattern;
LogicalResult
matchAndRewrite(ReturnOp op, ArrayRef<Value> operands,
ConversionPatternRewriter &rewriter) const override {
rewriter.replaceOpWithNewOp<ReturnOp>(op, operands);
return success();
}
};
/// Sparse conversion rule for dimension accesses.
class SparseTensorToDimSizeConverter
: public OpConversionPattern<tensor::DimOp> {
public:
using OpConversionPattern::OpConversionPattern;
LogicalResult
matchAndRewrite(tensor::DimOp op, ArrayRef<Value> operands,
ConversionPatternRewriter &rewriter) const override {
if (!operands[0].getType().isa<LLVM::LLVMPointerType>())
return failure();
Type resType = op.getType();
StringRef name = "sparseDimSize";
rewriter.replaceOpWithNewOp<CallOp>(
op, resType, getFunc(op, name, resType, operands), operands);
return success();
}
};
/// Sparse conversion rule for the new operator.
class SparseTensorNewConverter : public OpConversionPattern<NewOp> {
using OpConversionPattern::OpConversionPattern;
LogicalResult
matchAndRewrite(NewOp op, ArrayRef<Value> operands,
ConversionPatternRewriter &rewriter) const override {
Location loc = op.getLoc();
Type resType = op.getType();
Type eltType = resType.cast<ShapedType>().getElementType();
MLIRContext *context = op->getContext();
SmallVector<Value, 5> params;
// Sparse encoding.
auto enc = getSparseTensorEncoding(resType);
if (!enc)
return failure();
// User pointer.
params.push_back(operands[0]);
// Sparsity annotations in tensor constant form.
SmallVector<APInt, 4> attrs;
unsigned sz = enc.getDimLevelType().size();
for (unsigned i = 0; i < sz; i++)
attrs.push_back(
APInt(8, getDimLevelTypeEncoding(enc.getDimLevelType()[i])));
params.push_back(getTensor(rewriter, 8, loc, attrs));
// Dimension order permutation array. This is the "identity"
// permutation by default, or otherwise the "reverse" permutation
// of a given ordering, so that indices can be mapped quickly
// to the right position.
SmallVector<APInt, 4> perm(sz);
AffineMap p = enc.getDimOrdering();
if (p) {
assert(p.isPermutation() && p.getNumResults() == sz);
for (unsigned i = 0; i < sz; i++)
perm[p.getDimPosition(i)] = APInt(64, i);
} else {
for (unsigned i = 0; i < sz; i++)
perm[i] = APInt(64, i);
}
params.push_back(getTensor(rewriter, 64, loc, perm));
// Secondary and primary types encoding.
unsigned secPtr = getOverheadTypeEncoding(enc.getPointerBitWidth());
unsigned secInd = getOverheadTypeEncoding(enc.getIndexBitWidth());
unsigned primary;
if (eltType.isF64())
primary = 1;
else if (eltType.isF32())
primary = 2;
else if (eltType.isInteger(32))
primary = 3;
else if (eltType.isInteger(16))
primary = 4;
else if (eltType.isInteger(8))
primary = 5;
else
return failure();
params.push_back(
rewriter.create<ConstantOp>(loc, rewriter.getI64IntegerAttr(secPtr)));
params.push_back(
rewriter.create<ConstantOp>(loc, rewriter.getI64IntegerAttr(secInd)));
params.push_back(
rewriter.create<ConstantOp>(loc, rewriter.getI64IntegerAttr(primary)));
// Generate the call to create new tensor.
Type ptrType = LLVM::LLVMPointerType::get(IntegerType::get(context, 8));
StringRef name = "newSparseTensor";
rewriter.replaceOpWithNewOp<CallOp>(
op, ptrType, getFunc(op, name, ptrType, params), params);
return success();
}
};
/// Sparse conversion rule for pointer accesses.
class SparseTensorToPointersConverter
: public OpConversionPattern<ToPointersOp> {
public:
using OpConversionPattern::OpConversionPattern;
LogicalResult
matchAndRewrite(ToPointersOp op, ArrayRef<Value> operands,
ConversionPatternRewriter &rewriter) const override {
Type resType = op.getType();
Type eltType = resType.cast<ShapedType>().getElementType();
StringRef name;
if (eltType.isIndex())
name = "sparsePointers";
else if (eltType.isInteger(64))
name = "sparsePointers64";
else if (eltType.isInteger(32))
name = "sparsePointers32";
else if (eltType.isInteger(16))
name = "sparsePointers16";
else if (eltType.isInteger(8))
name = "sparsePointers8";
else
return failure();
rewriter.replaceOpWithNewOp<CallOp>(
op, resType, getFunc(op, name, resType, operands), operands);
return success();
}
};
/// Sparse conversion rule for index accesses.
class SparseTensorToIndicesConverter : public OpConversionPattern<ToIndicesOp> {
public:
using OpConversionPattern::OpConversionPattern;
LogicalResult
matchAndRewrite(ToIndicesOp op, ArrayRef<Value> operands,
ConversionPatternRewriter &rewriter) const override {
Type resType = op.getType();
Type eltType = resType.cast<ShapedType>().getElementType();
StringRef name;
if (eltType.isIndex())
name = "sparseIndices";
else if (eltType.isInteger(64))
name = "sparseIndices64";
else if (eltType.isInteger(32))
name = "sparseIndices32";
else if (eltType.isInteger(16))
name = "sparseIndices16";
else if (eltType.isInteger(8))
name = "sparseIndices8";
else
return failure();
rewriter.replaceOpWithNewOp<CallOp>(
op, resType, getFunc(op, name, resType, operands), operands);
return success();
}
};
/// Sparse conversion rule for value accesses.
class SparseTensorToValuesConverter : public OpConversionPattern<ToValuesOp> {
public:
using OpConversionPattern::OpConversionPattern;
LogicalResult
matchAndRewrite(ToValuesOp op, ArrayRef<Value> operands,
ConversionPatternRewriter &rewriter) const override {
Type resType = op.getType();
Type eltType = resType.cast<ShapedType>().getElementType();
StringRef name;
if (eltType.isF64())
name = "sparseValuesF64";
else if (eltType.isF32())
name = "sparseValuesF32";
else if (eltType.isInteger(32))
name = "sparseValuesI32";
else if (eltType.isInteger(16))
name = "sparseValuesI16";
else if (eltType.isInteger(8))
name = "sparseValuesI8";
else
return failure();
rewriter.replaceOpWithNewOp<CallOp>(
op, resType, getFunc(op, name, resType, operands), operands);
return success();
}
};
/// Sparse conversion rule for tensor reconstruction.
class SparseTensorToTensorConverter : public OpConversionPattern<ToTensorOp> {
public:
using OpConversionPattern::OpConversionPattern;
LogicalResult
// Simply fold the operator into the pointer to the sparse storage scheme.
matchAndRewrite(ToTensorOp op, ArrayRef<Value> operands,
ConversionPatternRewriter &rewriter) const override {
// Check that all arguments of the tensor reconstruction operators are calls
// into the support library that query exactly the same opaque pointer.
Value ptr;
for (Value op : operands) {
if (auto call = op.getDefiningOp<CallOp>()) {
Value arg = call.getOperand(0);
if (!arg.getType().isa<LLVM::LLVMPointerType>())
return failure();
if (!ptr)
ptr = arg;
else if (arg != ptr)
return failure();
}
}
// If a single opaque pointer is found, perform the folding.
if (!ptr)
return failure();
rewriter.replaceOp(op, ptr);
return success();
}
};
} // namespace
/// Populates the given patterns list with conversion rules required for
/// the sparsification of linear algebra operations.
void mlir::populateSparseTensorConversionPatterns(TypeConverter &typeConverter,
RewritePatternSet &patterns) {
patterns.add<SparseReturnConverter, SparseTensorToDimSizeConverter,
SparseTensorNewConverter, SparseTensorToPointersConverter,
SparseTensorToIndicesConverter, SparseTensorToValuesConverter,
SparseTensorToTensorConverter>(typeConverter,
patterns.getContext());
}