Files
clang-p2996/mlir/lib/Dialect/SparseTensor/Transforms/SparseTensorConversion.cpp
Aart Bik d37d72eaf8 [mlir][sparse] use shared util for DimOp generation
This shares more code with existing utilities. Also, to be consistent,
we moved dimension permutation on the DimOp to the tensor lowering phase.
This way, both pre-existing DimOps on sparse tensors (not likely but
possible) as well as compiler generated DimOps are handled consistently.

Reviewed By: bixia

Differential Revision: https://reviews.llvm.org/D108309
2021-08-18 17:12:32 -07:00

436 lines
16 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 {
//===----------------------------------------------------------------------===//
// Helper methods.
//===----------------------------------------------------------------------===//
/// Returns internal type encoding for primary storage. Keep these
/// values consistent with the sparse runtime support library.
static unsigned getPrimaryTypeEncoding(Type tp) {
if (tp.isF64())
return 1;
if (tp.isF32())
return 2;
if (tp.isInteger(64))
return 3;
if (tp.isInteger(32))
return 4;
if (tp.isInteger(16))
return 5;
if (tp.isInteger(8))
return 6;
return 0;
}
/// Returns internal type encoding for overhead storage. Keep these
/// values consistent with the sparse runtime support library.
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. Keep these
/// values consistent with the sparse runtime support library.
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);
}
/// Generates a call into the "swiss army knife" method of the sparse runtime
/// support library for materializing sparse tensors into the computation.
static void genNewCall(ConversionPatternRewriter &rewriter, Operation *op,
SparseTensorEncodingAttr &enc, uint32_t action,
Value ptr) {
Location loc = op->getLoc();
ShapedType resType = op->getResult(0).getType().cast<ShapedType>();
SmallVector<Value, 8> params;
// 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 sizes array of the enveloping *dense* tensor. Useful for either
// verification of external data, or for construction of internal data.
auto shape = resType.getShape();
SmallVector<APInt, 4> sizes;
for (unsigned i = 0; i < sz; i++) {
uint64_t s = shape[i] == ShapedType::kDynamicSize ? 0 : shape[i];
sizes.push_back(APInt(64, s));
}
params.push_back(getTensor(rewriter, 64, loc, sizes));
// 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 = getPrimaryTypeEncoding(resType.getElementType());
assert(primary);
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)));
// User action and pointer.
params.push_back(
rewriter.create<ConstantOp>(loc, rewriter.getI32IntegerAttr(action)));
params.push_back(ptr);
// Generate the call to create new tensor.
Type ptrType =
LLVM::LLVMPointerType::get(IntegerType::get(op->getContext(), 8));
StringRef name = "newSparseTensor";
rewriter.replaceOpWithNewOp<CallOp>(
op, ptrType, getFunc(op, name, ptrType, params), params);
}
/// Generates a call that exposes the data pointer as a void pointer.
// TODO: probing the data pointer directly is a bit raw; we should replace
// this with proper memref util calls once they become available.
static bool genPtrCall(ConversionPatternRewriter &rewriter, Operation *op,
Value val, Value &ptr) {
Location loc = op->getLoc();
ShapedType sType = op->getResult(0).getType().cast<ShapedType>();
Type eltType = sType.getElementType();
// Specialize name for the data type. Even though the final buffferized
// version only operates on pointers, different names are required to
// ensure type correctness for all intermediate states.
StringRef name;
if (eltType.isF64())
name = "getPtrF64";
else if (eltType.isF32())
name = "getPtrF32";
else if (eltType.isInteger(64))
name = "getPtrI64";
else if (eltType.isInteger(32))
name = "getPtrI32";
else if (eltType.isInteger(16))
name = "getPtrI16";
else if (eltType.isInteger(8))
name = "getPtrI8";
else
return false;
auto memRefTp = MemRefType::get(sType.getShape(), eltType);
auto unrankedTp = UnrankedMemRefType::get(eltType, 0);
Value c = rewriter.create<memref::BufferCastOp>(loc, memRefTp, val);
Value d = rewriter.create<memref::CastOp>(loc, unrankedTp, c);
Type ptrType =
LLVM::LLVMPointerType::get(IntegerType::get(op->getContext(), 8));
auto call =
rewriter.create<CallOp>(loc, ptrType, getFunc(op, name, ptrType, d), d);
ptr = call.getResult(0);
return true;
}
//===----------------------------------------------------------------------===//
// Conversion rules.
//===----------------------------------------------------------------------===//
/// 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 {
Type resType = op.getType();
auto enc = getSparseTensorEncoding(op.source().getType());
if (!enc)
return failure();
// Permute the dim index.
Optional<int64_t> index = op.getConstantIndex();
if (!index.hasValue())
return failure();
int64_t idx = index.getValue();
AffineMap p = enc.getDimOrdering();
if (p) {
assert(p.isPermutation());
for (unsigned i = 0, sz = p.getNumResults(); i < sz; i++) {
if (p.getDimPosition(i) == idx) {
idx = i;
break;
}
}
}
// Generate the call.
StringRef name = "sparseDimSize";
SmallVector<Value, 2> params;
params.push_back(operands[0]);
params.push_back(
rewriter.create<ConstantOp>(op.getLoc(), rewriter.getIndexAttr(idx)));
rewriter.replaceOpWithNewOp<CallOp>(
op, resType, getFunc(op, name, resType, params), params);
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 {
Type resType = op.getType();
auto enc = getSparseTensorEncoding(resType);
if (!enc)
return failure();
genNewCall(rewriter, op, enc, 0, operands[0]);
return success();
}
};
/// Sparse conversion rule for the convert operator.
class SparseTensorConvertConverter : public OpConversionPattern<ConvertOp> {
using OpConversionPattern::OpConversionPattern;
LogicalResult
matchAndRewrite(ConvertOp op, ArrayRef<Value> operands,
ConversionPatternRewriter &rewriter) const override {
Type resType = op.getType();
auto encDst = getSparseTensorEncoding(resType);
auto encSrc = getSparseTensorEncoding(op.source().getType());
// TODO: implement sparse => sparse
// and sparse => dense
if (!encDst || encSrc)
return failure();
// This is a dense => sparse conversion.
Value ptr;
if (!genPtrCall(rewriter, op, operands[0], ptr))
return failure();
genNewCall(rewriter, op, encDst, 1, ptr);
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(64))
name = "sparseValuesI64";
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
//===----------------------------------------------------------------------===//
// Public method for populating conversion rules.
//===----------------------------------------------------------------------===//
/// 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, SparseTensorConvertConverter,
SparseTensorToPointersConverter, SparseTensorToIndicesConverter,
SparseTensorToValuesConverter, SparseTensorToTensorConverter>(
typeConverter, patterns.getContext());
}