Files
clang-p2996/mlir/lib/Dialect/Linalg/Transforms/DataLayoutPropagation.cpp
Zhuoran Yin 8cfd9b8821 [MLIR] Make generic skip packing init operand when not used in DataLayoutPropagation (#146139)
In both `bubbleUpPackOpThroughGenericOp()` or
`pushDownUnPackOpThroughGenericOp()`, we can simplify the lowered IR by
removing the pack of an empty when the init tensor isn't used in generic
op. Instead of packing an empty tensor, the empty tensor can be
forwarded to the generic output. This allows cleaner result after data
layout propagation.
2025-07-01 09:39:30 -04:00

1251 lines
51 KiB
C++

//===- DataLayoutPropagation.cpp -----------------------------------------===///
//
// 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
//
//===----------------------------------------------------------------------===//
#include "mlir/Dialect/Linalg/Passes.h"
#include "mlir/Dialect/Affine/IR/AffineOps.h"
#include "mlir/Dialect/Linalg/IR/Linalg.h"
#include "mlir/Dialect/Linalg/Transforms/Transforms.h"
#include "mlir/Dialect/Linalg/Utils/Utils.h"
#include "mlir/Dialect/Tensor/IR/Tensor.h"
#include "mlir/Dialect/Tensor/Utils/Utils.h"
#include "mlir/Dialect/Utils/IndexingUtils.h"
#include "mlir/IR/Dominance.h"
#include "mlir/Transforms/GreedyPatternRewriteDriver.h"
#include "llvm/ADT/SetOperations.h"
#include "llvm/ADT/SetVector.h"
#include "llvm/ADT/TypeSwitch.h"
#include "llvm/Support/Debug.h"
#include <optional>
namespace mlir {
#define GEN_PASS_DEF_LINALGDATALAYOUTPROPAGATION
#include "mlir/Dialect/Linalg/Passes.h.inc"
} // namespace mlir
using namespace mlir;
using namespace mlir::linalg;
#define DEBUG_TYPE "linalg-data-layout-propagation"
namespace {
static bool hasGatherSemantics(linalg::GenericOp genericOp) {
for (Operation &op : genericOp.getBody()->getOperations())
if (isa<tensor::ExtractOp, linalg::IndexOp>(op))
return true;
return false;
}
// The struct contains the infomation about mapping packing information to
// the iteration domain of Linalg ops.
struct PackInfo {
int64_t getNumTiledLoops() const { return tileToPointMapping.size(); };
// InnerDimsPos on iteration domain, which follows the order in pack ops.
SmallVector<int64_t> tiledDimsPos;
// The sizes of tiling data dimensions on iteration domain.
llvm::DenseMap<int64_t, OpFoldResult> domainDimAndTileMapping;
// The mapping from a dimension of iteration domain to the corresponding inner
// tiling dimension on iteration domain.
llvm::DenseMap<int64_t, int64_t> tileToPointMapping;
// The permutation of outer dims (on domain).
SmallVector<int64_t> outerDimsOnDomainPerm;
};
template <typename OpTy>
static FailureOr<PackInfo>
getPackingInfoFromOperand(OpOperand *opOperand, linalg::GenericOp genericOp,
OpTy packOrUnPackOp) {
static_assert(llvm::is_one_of<OpTy, linalg::PackOp, linalg::UnPackOp>::value,
"applies to only pack or unpack operations");
LLVM_DEBUG(
{ llvm::dbgs() << "--- Construct PackInfo From an operand ---\n"; });
AffineMap indexingMap = genericOp.getMatchingIndexingMap(opOperand);
SmallVector<AffineMap> indexingMaps = genericOp.getIndexingMapsArray();
SmallVector<utils::IteratorType> iterators =
genericOp.getIteratorTypesArray();
PackInfo packInfo;
int64_t origNumDims = indexingMap.getNumDims();
SmallVector<AffineExpr> exprs(indexingMap.getResults());
ArrayRef<int64_t> innerDimsPos = packOrUnPackOp.getInnerDimsPos();
for (auto [index, innerDimPos, tileSize] :
llvm::zip_equal(llvm::seq<unsigned>(0, innerDimsPos.size()),
innerDimsPos, packOrUnPackOp.getMixedTiles())) {
auto expr = exprs[innerDimPos];
if (!isa<AffineDimExpr>(expr))
return failure();
int64_t domainDimPos =
cast<AffineDimExpr>(exprs[innerDimPos]).getPosition();
if (!isParallelIterator(iterators[domainDimPos]))
return failure();
packInfo.tiledDimsPos.push_back(domainDimPos);
packInfo.domainDimAndTileMapping[domainDimPos] = tileSize;
packInfo.tileToPointMapping[domainDimPos] = origNumDims + index;
LLVM_DEBUG({
llvm::dbgs() << "map innerDimPos=" << innerDimPos
<< " to iteration dimension (d" << domainDimPos << ", d"
<< packInfo.tileToPointMapping[domainDimPos]
<< "), which has size=("
<< packInfo.domainDimAndTileMapping[domainDimPos] << ")\n";
});
}
// Bail out if a tiled dimension is present in a map but not as an affine dim
// expression.
auto areAllAffineDimExpr = [&](int dim) {
for (AffineMap map : indexingMaps) {
if (llvm::any_of(map.getResults(), [dim](AffineExpr expr) {
return expr.isFunctionOfDim(dim) && !isa<AffineDimExpr>(expr);
})) {
return false;
}
}
return true;
};
for (int64_t i : packInfo.tiledDimsPos)
if (!areAllAffineDimExpr(i))
return failure();
// Get the outer dims perm on the iteration domain. Start by identifying the
// set of domain dims affected by the outer permutation along with the
// permuted ordering for those dims. Then the full outer dims permutation can
// be constructed by replacing the affected dims with the permuted result in a
// numLoops-rank identity. e.g.
// outerDimsPerm = [1, 2, 0]
// indexingMap = (d0, d1, d2, d3, d4) -> (d1, d4, d3)
//
// permutedOuterDims = [4, 3, 1]
// outerDimsOnDomainPerm = [0, 4, 2, 3, 1]
//
// Non-affine dim expressions must not be permuted by the outer dims
// permutation.
SmallVector<int64_t> permutedOuterDims;
for (auto [index, dim] : llvm::enumerate(packOrUnPackOp.getOuterDimsPerm())) {
auto permutedExpr = indexingMap.getResult(dim);
if (auto dimExpr = dyn_cast<AffineDimExpr>(permutedExpr)) {
permutedOuterDims.push_back(dimExpr.getPosition());
continue;
}
// TODO: Allow propagation with transposes on non affine dim expressions,
// e.g. d0 + d1 which implies transposing both dims simultaneously while
// maintaining the relative position between them.
if (static_cast<int64_t>(index) != dim)
return failure();
}
if (!permutedOuterDims.empty()) {
int64_t outerDimIndex = 0;
llvm::DenseSet<int64_t> permutedDomainDims(permutedOuterDims.begin(),
permutedOuterDims.end());
for (int i = 0, e = indexingMap.getNumDims(); i < e; i++)
packInfo.outerDimsOnDomainPerm.push_back(
permutedDomainDims.contains(i) ? permutedOuterDims[outerDimIndex++]
: i);
LLVM_DEBUG({
llvm::dbgs() << "map outer dimsDimsPerm to ";
for (auto dim : packInfo.outerDimsOnDomainPerm)
llvm::dbgs() << dim << " ";
llvm::dbgs() << "\n";
});
}
return packInfo;
}
static SmallVector<int64_t> computeOuterDims(ArrayRef<int64_t> perm,
ArrayRef<AffineExpr> exprs) {
// Compute `outer_dims_perm`. See example:
// current exprs : (d0, d1, d2, d3) -> (d2, d3)
// perm : [0, 3, 1, 2]
// First map d2, d3 with their position in the array as:
// currentPositionTileLoops: dim | pos
// d2 | 0
// d3 | 1
// then scan `perm` in order and get the `outer_dims_perm`
// to be used, here it would be [1, 0].
assert(!perm.empty() && "expect perm not to be empty");
assert(!exprs.empty() && "expect exprs not to be empty");
if (exprs.size() == 1)
return {};
SmallVector<int64_t> outerDimsPerm;
DenseMap<int64_t, int64_t> currentPositionTileLoops;
for (auto [pos, expr] : llvm::enumerate(exprs)) {
// Here we rely on the assumption that the outer dims permutation
// when propagating currently requires that non-affine dim expressions
// are not permuted, thus allowing the identity assignment below.
if (auto dimExpr = dyn_cast<AffineDimExpr>(expr))
currentPositionTileLoops[dimExpr.getPosition()] = pos;
else
currentPositionTileLoops[pos] = pos;
}
for (int64_t loopIdx : perm) {
if (currentPositionTileLoops.count(loopIdx))
outerDimsPerm.push_back(currentPositionTileLoops.lookup(loopIdx));
}
return outerDimsPerm;
}
/// Returns a tuple for packed operand and indexing_map with the assumptions:
/// 1) The generic op is the producer of the pack op.
/// 2) The generic op has only one result.
/// If the operand is a scalar or packing dimensions are all irrelevant to the
/// operand, the operand and the updated indexing map will be returned.
/// Otherwise, it returns the packed operand and the updated indexing map. E.g.,
///
/// #map0 = affine_map<(d0, d1) -> (d0, d1)>
/// #map1 = affine_map<(d0, d1) -> (d0)>
/// #map2 = affine_map<(d0, d1) -> (d1)>
/// %0 = linalg.generic {indexing_maps = [#map1, #map2, #map0],
/// iterator_types = ["parallel", "parallel"]}
/// ins(%arg0, %arg1 : tensor<?xf32>, tensor<?xf32>)
/// outs(%init : tensor<?x?xf32>) {
/// ^bb0(%arg3: f32, %arg4: f32, %arg5: f32):
/// %4 = arith.addf %arg3, %arg4 : f32
/// linalg.yield %4 : f32
/// } -> tensor<?x?xf32>
/// %1 = linalg.pack %0
/// inner_dims_pos = [0, 1]
/// inner_tiles = [8, 2]
/// into %dest : tensor<?x?xf32> -> tensor<?x?x8x2xf32>
///
/// Taking the first input operand as an example, the inner tile size of d1 is
/// 8. Thus, the below operation and `affine_map<(d0, d1, d2, d3)> ->
/// affine_map<(d1, d3)>` will be returned.
///
/// %pack = linalg.pack %arg0
/// inner_dims_pos = [0]
/// inner_tiles = [8]
/// into %init : tensor<?xf32> -> tensor<?x8xf32>
static std::tuple<Value, AffineMap>
getOrCreatePackedViewOfOperand(OpBuilder &b, Location loc, PackInfo packInfo,
GenericOp genericOp, OpOperand *opOperand) {
int64_t numOrigLoops = genericOp.getNumLoops();
int64_t numInnerLoops = packInfo.getNumTiledLoops();
int64_t numLoops = numOrigLoops + numInnerLoops;
AffineMap origIndexingMap = genericOp.getMatchingIndexingMap(opOperand);
llvm::DenseMap<int64_t, int64_t> domainDimToOperandDim;
SmallVector<AffineExpr> exprs(origIndexingMap.getResults());
// If the OpOperand is a scalar or a zero-rank tensor, no need to pack.
if (genericOp.isScalar(opOperand) || exprs.empty())
return std::make_tuple(opOperand->get(),
AffineMap::get(numLoops, 0, exprs, b.getContext()));
// Step 1. Construct the information of packing data dimensions; append inner
// dimensions to the indexing maps for the operand.
for (auto [index, expr] : llvm::enumerate(exprs)) {
if (auto dimExpr = dyn_cast<AffineDimExpr>(expr)) {
int64_t dimPos = dimExpr.getPosition();
domainDimToOperandDim[dimPos] = index;
continue;
}
}
SmallVector<int64_t> innerDimsPos;
SmallVector<OpFoldResult> innerTileSizes;
for (auto dimPos : packInfo.tiledDimsPos) {
if (!domainDimToOperandDim.count(dimPos))
continue;
int64_t index = domainDimToOperandDim[dimPos];
innerTileSizes.push_back(packInfo.domainDimAndTileMapping[dimPos]);
innerDimsPos.push_back(index);
exprs.push_back(b.getAffineDimExpr(packInfo.tileToPointMapping[dimPos]));
}
// Step 2. Handle outer dim permutations.
SmallVector<int64_t> outerDimsPerm;
if (!packInfo.outerDimsOnDomainPerm.empty()) {
outerDimsPerm = computeOuterDims(packInfo.outerDimsOnDomainPerm, exprs);
// Step 2.1: Fold transpose into the linalg.generic.
SmallVector<int64_t> inversedOuterPerm =
invertPermutationVector(packInfo.outerDimsOnDomainPerm);
for (auto i : llvm::seq<unsigned>(0, origIndexingMap.getNumResults())) {
if (auto dimExpr = dyn_cast<AffineDimExpr>(exprs[i])) {
int64_t dimPos = dimExpr.getPosition();
exprs[i] = b.getAffineDimExpr(inversedOuterPerm[dimPos]);
continue;
}
assert(isa<AffineConstantExpr>(exprs[i]) &&
"Attempted to permute non-constant and non-affine dim expression");
}
// Step 2.2: Undo the transposition on `exprs` and propagate the
// transposition on the pack using outerDimsPerm.
if (!outerDimsPerm.empty()) {
SmallVector<AffineExpr> auxVec = exprs;
for (const auto &en : enumerate(outerDimsPerm))
auxVec[en.index()] = exprs[en.value()];
exprs = auxVec;
}
}
auto indexingMap = AffineMap::get(numLoops, 0, exprs, b.getContext());
// The operand does not have dimensions that relates to pack op.
if (innerDimsPos.empty() && outerDimsPerm.empty())
return std::make_tuple(opOperand->get(), indexingMap);
auto empty = linalg::PackOp::createDestinationTensor(
b, loc, opOperand->get(), innerTileSizes, innerDimsPos, outerDimsPerm);
auto packedOperand = b.create<linalg::PackOp>(
loc, opOperand->get(), empty, innerDimsPos, innerTileSizes,
/*padding=*/std::nullopt, outerDimsPerm);
return std::make_tuple(packedOperand, indexingMap);
}
/// This function is a helper subroutine to pack a genericOp and return it. It
/// will create a new generic op with the packed operand and the packed output
/// according to packInfo when we attempt to push down unpack or bubble up pack
/// around it. Implicitly this will only work when a packInfo can be obtained.
/// This make sure that we are only using this function on parallel permuted
/// dimensions.
static GenericOp packGenericOp(RewriterBase &rewriter, GenericOp genericOp,
Value dest, AffineMap packedOutIndexingMap,
const PackInfo &packInfo,
bool isFoldableUnpackPack) {
Location loc = genericOp.getLoc();
SmallVector<Value> inputOperands;
SmallVector<Value> inputOperandsFromUnpackedSource;
SmallVector<AffineMap> indexingMaps;
auto hasEquivalentTiles = [](PackOp packOp, UnPackOp unPackOp) {
return packOp.getOuterDimsPerm() == unPackOp.getOuterDimsPerm() &&
packOp.getInnerDimsPos() == unPackOp.getInnerDimsPos() &&
llvm::equal(packOp.getMixedTiles(), unPackOp.getMixedTiles());
};
for (OpOperand *inputOperand : genericOp.getDpsInputOperands()) {
auto [packedOperand, packedIndexingMap] = getOrCreatePackedViewOfOperand(
rewriter, loc, packInfo, genericOp, inputOperand);
auto unpackOp = inputOperand->get().getDefiningOp<linalg::UnPackOp>();
auto packOp = packedOperand.getDefiningOp<linalg::PackOp>();
if (packOp && unpackOp && hasEquivalentTiles(packOp, unpackOp)) {
inputOperandsFromUnpackedSource.push_back(unpackOp.getSource());
} else {
inputOperandsFromUnpackedSource.push_back(packedOperand);
}
inputOperands.push_back(packedOperand);
indexingMaps.push_back(packedIndexingMap);
}
// If the unpack->pack sequences can be folded, replace use the sources of
// the unpack ops in any unpack->pack chains on the generic op operands.
if (isFoldableUnpackPack) {
inputOperands = inputOperandsFromUnpackedSource;
if (auto destPack = dest.getDefiningOp<linalg::PackOp>()) {
auto destUnPack = destPack.getSource().getDefiningOp<linalg::UnPackOp>();
if (destUnPack && hasEquivalentTiles(destPack, destUnPack)) {
dest = destUnPack.getSource();
}
}
}
int64_t numInnerLoops = packInfo.getNumTiledLoops();
SmallVector<utils::IteratorType> iterTypes =
genericOp.getIteratorTypesArray();
iterTypes.append(numInnerLoops, utils::IteratorType::parallel);
indexingMaps.push_back(packedOutIndexingMap);
auto newGenericOp = rewriter.create<linalg::GenericOp>(
loc, dest.getType(), inputOperands, dest, indexingMaps, iterTypes,
/*bodyBuild=*/nullptr, linalg::getPrunedAttributeList(genericOp));
rewriter.cloneRegionBefore(genericOp.getRegion(), newGenericOp.getRegion(),
newGenericOp.getRegion().begin());
return newGenericOp;
}
static bool isGenericOutsNotUsed(linalg::GenericOp genericOp) {
return llvm::all_of(genericOp.getDpsInitsMutable(), [&](OpOperand &operand) {
return genericOp.getMatchingBlockArgument(&operand).use_empty();
});
}
/// Bubbles up linalg.pack op through a producer generic op. This
/// swap pack(generic) to generic(pack). The new generic op works on packed
/// domain; pack ops are created for input and output operands. E.g.,
///
/// #map0 = affine_map<(d0, d1) -> (d0, d1)>
/// %0 = tensor.dim %arg0, %c0 : tensor<?x?xf32>
/// %1 = tensor.dim %arg0, %c1 : tensor<?x?xf32>
/// %2 = tensor.empty(%0, %1) : tensor<?x?xf32>
/// %3 = linalg.generic {indexing_maps = [#map0, #map0],
/// iterator_types = ["parallel", "parallel"]}
/// ins(%arg0 : tensor<?x?xf32>)
/// outs(%2 : tensor<?x?xf32>) {
/// ^bb0(%arg3: f32, %arg4: f32):
/// %4 = arith.addf %arg3, %arg3 : f32
/// linalg.yield %4 : f32
/// } -> tensor<?x?xf32>
/// %4 = linalg.pack %3
/// inner_dims_pos = [0, 1]
/// inner_tiles = [8, 2]
/// into %dest : tensor<?x?xf32> -> tensor<?x?x8x2xf32>
///
/// will be converted to
///
/// #map = affine_map<()[s0] -> (s0 ceildiv 8)>
/// #map1 = affine_map<()[s0] -> (s0 ceildiv 2)>
/// #map2 = affine_map<(d0, d1, d2, d3) -> (d0, d1, d2, d3)>
/// %dim = tensor.dim %arg0, %c0 : tensor<?x?xf32>
/// %dim_0 = tensor.dim %arg0, %c1 : tensor<?x?xf32>
/// %0 = affine.apply #map()[%dim]
/// %1 = affine.apply #map1()[%dim_0]
/// %2 = tensor.empty(%0, %1) : tensor<?x?x8x2xf32>
/// %pack = linalg.pack %arg0
/// inner_dims_pos = [0, 1]
/// inner_tiles = [8, 2]
/// into %2 : tensor<?x?xf32> -> tensor<?x?x8x2xf32>
/// %3 = linalg.generic {indexing_maps = [#map2, #map2],
/// iterator_types = ["parallel", "parallel", "parallel", "parallel"]}
/// ins(%pack : tensor<?x?x8x2xf32>)
/// outs(%arg1 : tensor<?x?x8x2xf32>) {
/// ^bb0(%in: f32, %out: f32):
/// %4 = arith.addf %in, %in : f32
/// linalg.yield %4 : f32
/// } -> tensor<?x?x8x2xf32>
static FailureOr<GenericOp>
bubbleUpPackOpThroughGenericOp(RewriterBase &rewriter, linalg::PackOp packOp,
const ControlPropagationFn &controlFn) {
auto genericOp = packOp.getSource().getDefiningOp<GenericOp>();
if (!genericOp)
return failure();
// User controlled propagation function.
if (!controlFn(&packOp.getSourceMutable()))
return failure();
// TODO: Enable propagation in the presence of linalg.index and
// tensor.extract, likely as a separate pattern as the pack information and
// propagation decision needs to be inferred from the region of the generic.
if (hasGatherSemantics(genericOp))
return failure();
// TODO: Relax the restriction. We are able to bubble up the pack op through
// multi-result generic op. It just needs more work.
if (genericOp.getNumResults() != 1)
return failure();
// Bail-out if the result of the generic has multiple uses, as bubbling up
// creates recomputation if the generic has multiple users.
// TODO: Enable the case where every use is an identical pack op as no
// recomputation is needed in that case.
if (!genericOp->getResult(0).hasOneUse())
return failure();
// TODO: Add an option for allowing padding values. It could introduce
// undefined behavior if we unconditionally propagate pack op through all
// the ops. E.g., if the padding value is zero and there are division ops in
// a generic op. Some values of padding area could be NaN (0/0).
if (packOp.getPaddingValue())
return failure();
OpOperand *opOperand = genericOp.getDpsInitOperand(0);
auto packInfo = getPackingInfoFromOperand(opOperand, genericOp, packOp);
if (failed(packInfo))
return failure();
// We want to move the pack not the generic.
OpBuilder::InsertionGuard guard(rewriter);
rewriter.setInsertionPoint(genericOp);
// We need to handle two cases:
// 1) The linalg.pack destination is a tensor.empty. If this is the case, we
// create a new tensor.empty to avoid breaking dominance, as we are moving the
// linalg.pack above the linalg.generic.
// 2) The destination is not a tensor.empty. In this case we can replace only
// if the destination of the linalg.pack dominates the linalg.generic.
Value packOpDest = packOp.getDest();
if (!packOpDest.hasOneUse())
return failure();
if (auto emptyOp = packOpDest.getDefiningOp<tensor::EmptyOp>()) {
packOpDest = rewriter.create<tensor::EmptyOp>(
genericOp->getLoc(), emptyOp.getMixedSizes(),
emptyOp.getType().getElementType());
} else {
DominanceInfo dom(genericOp);
if (!dom.properlyDominates(packOpDest, genericOp))
return failure();
}
// Rebuild the indexing map for the corresponding init operand.
auto [packedOutOperand, packedOutIndexingMap] =
getOrCreatePackedViewOfOperand(rewriter, genericOp.getLoc(), *packInfo,
genericOp, opOperand);
// Forward the new tensor.empty as a destination if it is one of the following
// situations:
// 1) The dps init operand is a tensor.empty.
// 2) The dps init is a write-only operand, i.e., it is not used in the
// genericOp
Value dest = packedOutOperand;
auto initTensor =
genericOp.getDpsInitOperand(0)->get().getDefiningOp<tensor::EmptyOp>();
if (initTensor || isGenericOutsNotUsed(genericOp)) {
dest = packOpDest;
}
// pack(unpack) isn't naively foldable because the unpack op can be from
// an arbitrary domain so we need to keep both.
return packGenericOp(rewriter, genericOp, dest, packedOutIndexingMap,
*packInfo, /*isFoldableUnpackPack=*/false);
}
/// Wrapper pattern that applies bubbleUpPackOpThroughGenericOp method.
struct BubbleUpPackOpThroughGenericOpPattern
: public OpRewritePattern<linalg::PackOp> {
public:
BubbleUpPackOpThroughGenericOpPattern(MLIRContext *context,
ControlPropagationFn fun)
: OpRewritePattern<linalg::PackOp>(context), controlFn(std::move(fun)) {}
LogicalResult matchAndRewrite(linalg::PackOp packOp,
PatternRewriter &rewriter) const override {
auto genericOp =
bubbleUpPackOpThroughGenericOp(rewriter, packOp, controlFn);
if (failed(genericOp))
return failure();
rewriter.replaceOp(packOp, genericOp->getResults());
return success();
}
private:
ControlPropagationFn controlFn;
};
/// Propagate a linalg.pack operation up through a tensor.pad. The idea is to
/// add as many zero padding dimensions in `high` and `low` based on the number
/// of point loops.
class BubbleUpPackThroughPadOp final : public OpRewritePattern<linalg::PackOp> {
public:
BubbleUpPackThroughPadOp(MLIRContext *context, ControlPropagationFn fun)
: OpRewritePattern<linalg::PackOp>(context), controlFn(std::move(fun)) {}
LogicalResult matchAndRewrite(linalg::PackOp packOp,
PatternRewriter &rewriter) const override {
auto padOp = packOp.getSource().getDefiningOp<tensor::PadOp>();
if (!padOp)
return failure();
// User controlled propagation function.
if (!controlFn(&packOp.getSourceMutable()))
return failure();
// TODO: Enable padding when the padding values are the same.
if (packOp.getPaddingValue())
return failure();
// Fail for non-constant padding values. The body of the pad could
// depend on the padding indices and/or properties of the padded
// tensor so for now we fail.
// TODO: Support non-constant padding values.
Value paddingVal = padOp.getConstantPaddingValue();
if (!paddingVal)
return failure();
if (!packOp.getDest().getDefiningOp<tensor::EmptyOp>())
return failure();
ArrayRef<int64_t> innerDimsPos = packOp.getInnerDimsPos();
// Bail out if one of the padded dimension is a tiled one.
llvm::SmallBitVector paddedDims = padOp.getPaddedDims();
llvm::SmallBitVector innerDims(paddedDims.size());
for (int64_t dim : innerDimsPos)
innerDims.flip(dim);
if (paddedDims.anyCommon(innerDims))
return failure();
Location loc = padOp->getLoc();
OpBuilder::InsertionGuard guard(rewriter);
rewriter.setInsertionPoint(padOp);
ArrayRef<int64_t> outerDimsPerm = packOp.getOuterDimsPerm();
SmallVector<OpFoldResult> mixedTiles = packOp.getMixedTiles();
auto empty = linalg::PackOp::createDestinationTensor(
rewriter, loc, padOp.getSource(), mixedTiles, innerDimsPos,
outerDimsPerm);
auto sourcePack = rewriter.create<linalg::PackOp>(
loc, padOp.getSource(), empty, innerDimsPos, mixedTiles,
/*padding=*/std::nullopt, outerDimsPerm);
// If we have `outer_dims_perms` we need to adjust the padded dimensions.
SmallVector<OpFoldResult> lowPad = padOp.getMixedLowPad();
SmallVector<OpFoldResult> highPad = padOp.getMixedHighPad();
if (!outerDimsPerm.empty()) {
applyPermutationToVector<OpFoldResult>(lowPad, outerDimsPerm);
applyPermutationToVector<OpFoldResult>(highPad, outerDimsPerm);
}
// The tiled dimensions were verified to be unpadded above, so here we
// just append 0 for the inner tile dimensions.
size_t pointLoopsSize = innerDimsPos.size();
lowPad.append(pointLoopsSize, rewriter.getIndexAttr(0));
highPad.append(pointLoopsSize, rewriter.getIndexAttr(0));
auto newPadOp = rewriter.create<tensor::PadOp>(
loc, /*result=*/Type(), sourcePack, lowPad, highPad, paddingVal,
padOp.getNofold());
// If the pad has more than one user, create an unpack on the new pad to
// replace the other uses.
if (!padOp->hasOneUse()) {
auto unpackEmpty = linalg::UnPackOp::createDestinationTensor(
rewriter, loc, newPadOp, mixedTiles, innerDimsPos, outerDimsPerm);
Value unpackedPad = rewriter.create<linalg::UnPackOp>(
loc, newPadOp, unpackEmpty, innerDimsPos, mixedTiles, outerDimsPerm);
rewriter.replaceAllUsesExcept(padOp, unpackedPad, sourcePack);
}
// Replace the pack with the new pad.
rewriter.replaceOp(packOp, newPadOp.getResult());
return success();
}
private:
ControlPropagationFn controlFn;
};
/// Project dimsPos to the inner-most non-unit dim pos with reassocIndices.
///
/// For example, given dimsPos [0, 2], reassocIndices [[0, 1], [2, 3]], and
/// targetShape [16, 16, 32, 1], it returns [1, 2]. Because for pos 0, the
/// inner-most projected dim in pos [0, 1] is 1. And for pos 2, the inner-most
/// non-unit projected dims in pos [2, 3] is 2.
///
/// If all candidates in a reassociation are unit dims, it chooses the
/// inner-most dim pos.
static SmallVector<int64_t>
projectToInnerMostNonUnitDimsPos(ArrayRef<int64_t> dimsPos,
ArrayRef<ReassociationIndices> reassocIndices,
ArrayRef<int64_t> targetShape) {
SmallVector<int64_t> projectedDimsPos;
for (auto pos : dimsPos) {
// In the case all dims are unit, this will return the inner-most one.
int64_t projectedPos = reassocIndices[pos].back();
for (auto i : llvm::reverse(reassocIndices[pos])) {
int64_t dim = targetShape[i];
if (dim > 1 || ShapedType::isDynamic(dim)) {
projectedPos = i;
break;
}
}
projectedDimsPos.push_back(projectedPos);
}
return projectedDimsPos;
}
/// Check if all dims in dimsPos are divisible by the corresponding tile sizes.
static bool isDimsDivisibleByTileSizes(ArrayRef<int64_t> dimsPos,
ArrayRef<int64_t> shape,
ArrayRef<int64_t> tileSizes) {
for (auto [pos, tileSize] : llvm::zip_equal(dimsPos, tileSizes)) {
int64_t dim = shape[pos];
if (ShapedType::isDynamic(dim) || (dim % tileSize) != 0)
return false;
}
return true;
}
/// Permutate the reassociation indices and reindex them in the sequence order.
/// Returns the next dim pos in the sequence.
///
/// For example, given reassocIndices [[0, 1], [2]] and permutation [1, 0], it
/// applies the permutation to get [[2], [0, 1]] and reindexes the indices into
/// [[0], [1, 2]].
static int64_t applyPermutationAndReindexReassoc(
SmallVector<ReassociationIndices> &reassocIndices,
ArrayRef<int64_t> permutation) {
if (!permutation.empty())
applyPermutationToVector<ReassociationIndices>(reassocIndices, permutation);
int64_t nextPos = 0;
for (ReassociationIndices &indices : reassocIndices) {
for (auto &index : indices) {
index = nextPos;
nextPos += 1;
}
}
return nextPos;
}
/// Bubble up pack op through collapse shape op when the packed dims can be
/// projected to the dims before collapsing. This is possible when the inner
/// tile sizes can divide the projected dims.
///
/// For example:
///
/// %collapsed = tensor.collapse_shape %in [[0, 1], 2]
/// : tensor<?x16x4xf32> into tensor<?x4xf32>
/// %pack = linalg.pack %collapsed outer_dims_perm = [0, 1]
/// inner_dims_pos = [0, 1] inner_tiles = [8, 1] into %empty
/// : tensor<?x4xf32> -> tensor<?x4x8x1xf32>
///
/// can be transformed into:
///
/// %pack = linalg.pack %in outer_dims_perm = [1, 2]
/// inner_dims_pos = [1, 2] inner_tiles = [8, 1] into %empty
/// : tensor<?x16x4xf32> -> tensor<?x2x4x8x1xf32>
/// %collapsed = tensor.collapse_shape %pack [[0, 1], 2, 3, 4]
/// : tensor<?x2x4x8x1xf32> into tensor<?x4x8x1>
static LogicalResult
bubbleUpPackOpThroughCollapseShape(tensor::CollapseShapeOp collapseOp,
linalg::PackOp packOp,
PatternRewriter &rewriter) {
SmallVector<int64_t> innerTileSizes = packOp.getStaticTiles();
ArrayRef<int64_t> innerDimsPos = packOp.getInnerDimsPos();
ArrayRef<int64_t> outerDimsPerm = packOp.getOuterDimsPerm();
ArrayRef<int64_t> srcShape = collapseOp.getSrcType().getShape();
SmallVector<ReassociationIndices> reassocIndices =
collapseOp.getReassociationIndices();
// Project inner tile pos to the dim pos before collapsing. For example, if
// dims [x, y] is collapsed into [z], packing on dim z can be projected back
// to pack on dim y.
//
// Project to inner-most non-unit dims to increase the chance that they can be
// divided by the inner tile sizes. This is correct because for [..., x, 1],
// packing on dim 1 is equivalent to packing on dim x.
SmallVector<int64_t> projectedInnerDimsPos =
projectToInnerMostNonUnitDimsPos(innerDimsPos, reassocIndices, srcShape);
if (!isDimsDivisibleByTileSizes(projectedInnerDimsPos, srcShape,
innerTileSizes)) {
return failure();
}
// Expand the outer dims permutation with the associated source dims for the
// new permutation after bubbling. This is because moving a collapsed dim is
// equivalent to moving the associated source dims together.
SmallVector<int64_t> newOuterDimsPerm;
for (auto outerPos : outerDimsPerm)
llvm::append_range(newOuterDimsPerm, reassocIndices[outerPos]);
auto emptyOp = linalg::PackOp::createDestinationTensor(
rewriter, packOp.getLoc(), collapseOp.getSrc(), packOp.getMixedTiles(),
projectedInnerDimsPos, newOuterDimsPerm);
auto newPackOp = rewriter.create<linalg::PackOp>(
packOp.getLoc(), collapseOp.getSrc(), emptyOp, projectedInnerDimsPos,
packOp.getMixedTiles(), packOp.getPaddingValue(), newOuterDimsPerm);
SmallVector<ReassociationIndices> newReassocIndices = reassocIndices;
// First apply the permutation on the reassociations of the outer dims.
// For example given the permutation [1, 0], the reassociations [[0, 1], [2]]
// -> [[0], [1, 2]]
int64_t nextPos =
applyPermutationAndReindexReassoc(newReassocIndices, outerDimsPerm);
// Then add direct mapping for the inner tile dims.
for (size_t i = 0; i < innerDimsPos.size(); ++i) {
newReassocIndices.push_back({nextPos});
nextPos += 1;
}
auto newCollapseOp = rewriter.create<tensor::CollapseShapeOp>(
collapseOp.getLoc(), packOp.getType(), newPackOp, newReassocIndices);
rewriter.replaceOp(packOp, newCollapseOp);
return success();
}
/// Project dimsPos to their collapsed positions in the reassocIndices.
///
/// For example, given dimsPos [0, 1, 2, 4], and matching reassocIndices
/// [[0], [1, 2], [3], [4]], it returns [0, 1, 1, 3]. Because for pos 0,
/// the reassoc dim [0] is 0. For pos 1 and 2, the reassoc dim in pos
/// [1, 2] is 1. And for pos 4, the reassoc dim [4] is 3.
static SmallVector<int64_t>
projectDimsPosIntoReassocPos(ArrayRef<int64_t> dimsPos,
ArrayRef<ReassociationIndices> reassocIndices) {
SmallVector<int64_t> projectedPos;
// Map each dimension to the position of corresponding reassociation index.
for (auto pos : dimsPos) {
for (auto [idx, indices] : llvm::enumerate(reassocIndices)) {
// If the dimension is present in the current indices group, the group
// position within the reassociation map is the desired projected
// dimension position.
if (llvm::is_contained(indices, pos)) {
projectedPos.push_back(idx);
break;
}
}
}
assert(projectedPos.size() == dimsPos.size() && "Invalid dim pos projection");
return projectedPos;
}
/// Bubble up pack op through expand shape op.
///
/// For example:
///
/// %expand = tensor.expand_shape %in [[0], [1, 2]]
/// : tensor<?x64xf32> into tensor<?x4x16xf32>
/// %pack = linalg.pack %expand outer_dims_perm = [0, 1]
/// inner_dims_pos = [2] inner_tiles = [8] into %empty
/// : tensor<?x4x16xf32> -> tensor<?x4x2x8xf32>
///
/// can be transformed into:
///
/// %pack = linalg.pack %in outer_dims_perm = [1, 2]
/// inner_dims_pos = [1] inner_tiles = [8] into %empty
/// : tensor<?x64xf32> -> tensor<?x8x8xf32>
/// %expand = tensor.expand_shape %pack [[0], [1, 2], [3]]
/// : tensor<?x8x8xf32> into tensor<?x4x2x8xf32>
static LogicalResult
bubbleUpPackOpThroughExpandShape(tensor::ExpandShapeOp expandOp,
linalg::PackOp packOp,
PatternRewriter &rewriter) {
// Outer dimensions permutation is not supported currently.
// TODO: Handle outer_dims_perm variants.
ArrayRef<int64_t> outerDimsPerm = packOp.getOuterDimsPerm();
if (!outerDimsPerm.empty() && !isIdentityPermutation(outerDimsPerm)) {
return rewriter.notifyMatchFailure(packOp,
"non-identity outer dims perm NYI");
}
// Validate dimensions' relations between shape expansion and packing.
SmallVector<ReassociationIndices, 4> reassoc =
expandOp.getReassociationIndices();
ArrayRef<int64_t> packInnerDims = packOp.getInnerDimsPos();
llvm::SetVector<int64_t> packDimsPos(llvm::from_range, packInnerDims);
for (auto [idx, indices] : llvm::enumerate(reassoc)) {
// For each expand_shape reassociation, figure out which dimensions get
// packed if any.
llvm::SetVector<int64_t> expandDimPos(llvm::from_range, indices);
llvm::SetVector<int64_t> packedDims =
llvm::set_intersection(packDimsPos, expandDimPos);
// The expanded dimension is not packed so, it does not affect moving pack
// before shape expansion - simply continue.
if (packedDims.empty())
continue;
// Shape expansion cannot be propagated when multiple expanded dimension are
// packed - in this case operation reordering would affect final element
// positions and/or shapes can no longer be projected.
if (packedDims.size() != 1)
return rewriter.notifyMatchFailure(
packOp, "only one of the expanded dimensions can be packed");
// Only the inner-most expanded dimension should be packed. Otherwise,
// elements order will be affected after operation reordering.
if (packedDims.front() != indices.back())
return rewriter.notifyMatchFailure(
packOp, "can only pack the inner-most expanded dimension");
}
// Project pack.inner_dims_pos to positions before shape expansion.
SmallVector<int64_t> projectedInnerDimsPos =
projectDimsPosIntoReassocPos(packInnerDims, reassoc);
// Project the shape expansion to new packed shape.
// The pack.outer_dims_perm is restricted to identity so, the permutation can
// be omitted for simplicity.
// TODO: Account for outer dimensions permutation.
//
// If reassociation is not possible, then reordering cannot happen.
// This can be caused by pack padding affecting previously expanded
// dimensions or packing extending dimensions.
RankedTensorType newPackType = linalg::PackOp::inferPackedType(
expandOp.getSrcType(), packOp.getStaticInnerTiles(),
projectedInnerDimsPos, /*outerDimsPerm=*/SmallVector<int64_t>{});
auto reassocExpand =
getReassociationIndicesForReshape(newPackType, packOp.getDestType());
if (!reassocExpand)
return rewriter.notifyMatchFailure(
packOp, "could not reassociate dims after bubbling up");
Value destTensor = linalg::PackOp::createDestinationTensor(
rewriter, packOp.getLoc(), expandOp.getSrc(), packOp.getMixedTiles(),
projectedInnerDimsPos, /*outerDimsPerm=*/SmallVector<int64_t>{});
Value packedVal = rewriter.create<linalg::PackOp>(
packOp.getLoc(), expandOp.getSrc(), destTensor, projectedInnerDimsPos,
packOp.getMixedTiles(), packOp.getPaddingValue(),
/*outerDimsPerm=*/SmallVector<int64_t>{});
Value newExpandOp = rewriter.create<tensor::ExpandShapeOp>(
packOp.getLoc(), packOp.getDestType(), packedVal, *reassocExpand);
rewriter.replaceOp(packOp, newExpandOp);
return success();
}
class BubbleUpPackOpThroughReshapeOp final
: public OpRewritePattern<linalg::PackOp> {
public:
BubbleUpPackOpThroughReshapeOp(MLIRContext *context, ControlPropagationFn fun)
: OpRewritePattern<linalg::PackOp>(context), controlFn(std::move(fun)) {}
LogicalResult matchAndRewrite(linalg::PackOp packOp,
PatternRewriter &rewriter) const override {
Operation *srcOp = packOp.getSource().getDefiningOp();
// Currently only support when the pack op is the only user.
if (!srcOp || !(srcOp->getNumResults() == 1) ||
!srcOp->getResult(0).hasOneUse()) {
return failure();
}
// Currently only support static inner tile sizes.
if (llvm::any_of(packOp.getStaticTiles(), ShapedType::isDynamic))
return failure();
// User controlled propagation function.
if (!controlFn(&packOp.getSourceMutable()))
return failure();
return TypeSwitch<Operation *, LogicalResult>(srcOp)
.Case([&](tensor::CollapseShapeOp op) {
return bubbleUpPackOpThroughCollapseShape(op, packOp, rewriter);
})
.Case([&](tensor::ExpandShapeOp op) {
return bubbleUpPackOpThroughExpandShape(op, packOp, rewriter);
})
.Default([](Operation *) { return failure(); });
}
private:
ControlPropagationFn controlFn;
};
/// Push down unpack op through expand shape op when the packed dims can be
/// projected to the dims after expanding. This is possible when the inner tile
/// sizes can divide the projected dims.
///
/// For example:
///
/// %unpack = linalg.unpack %in outer_dims_perm = [0, 1]
/// inner_dims_pos = [0, 1] inner_tiles = [8, 8] into %empty
/// : tensor<?x32x8x8xf32> -> tensor<?x256xf32>
/// %expanded = tensor.expand_shape %unpack [[0, 1], [2]]
/// : tensor<?x256xf32> into tensor<?x256x256xf32>
///
/// can be transformed into:
///
/// %expanded = tensor.expand_shape %ain [[0, 1], [2], [3], [4]]
/// : tensor<?x32x8x8xf32> into tensor<?x32x32x8x8xf32>
/// %unpack = linalg.unpack %expanded outer_dims_perm = [0, 1, 2]
/// inner_dims_pos = [1, 2] inner_tiles = [8, 8] into %empty
/// : tensor<?x32x32x8x8xf32> -> tensor<?x256x256xf32>
static LogicalResult pushDownUnPackOpThroughExpandShape(
linalg::UnPackOp unPackOp, tensor::ExpandShapeOp expandOp,
PatternRewriter &rewriter, ControlPropagationFn controlFn) {
// User controlled propagation function.
if (!controlFn(&expandOp.getSrcMutable()))
return failure();
SmallVector<int64_t> innerTileSizes = unPackOp.getStaticTiles();
ArrayRef<int64_t> innerDimsPos = unPackOp.getInnerDimsPos();
ArrayRef<int64_t> outerDimsPerm = unPackOp.getOuterDimsPerm();
auto expandTy = dyn_cast<RankedTensorType>(expandOp.getType());
if (!expandTy)
return failure();
ArrayRef<int64_t> dstShape = expandTy.getShape();
SmallVector<ReassociationIndices> reassocIndices =
expandOp.getReassociationIndices();
// Project inner tile pos to the dim pos after expanding. For example, if dims
// [z] is expanded into [x, y], unpacking on dim z can be projected to unpack
// on dim y.
//
// Project to inner-most non-unit dims to increase the chance that they can be
// divided by the inner tile sizes. This is correct because for [..., x, 1],
// unpacking on dim 1 is equivalent to unpacking on dim x.
SmallVector<int64_t> projectedInnerDimsPos =
projectToInnerMostNonUnitDimsPos(innerDimsPos, reassocIndices, dstShape);
if (!isDimsDivisibleByTileSizes(projectedInnerDimsPos, dstShape,
innerTileSizes)) {
return failure();
}
// Expand the outer dims permutation with the associated expanded dims for the
// new permutation after pushing. This is because moving a source dim is
// equivalent to moving the associated expanded dims together.
SmallVector<int64_t> newOuterDimsPerm;
for (auto outerPos : outerDimsPerm)
llvm::append_range(newOuterDimsPerm, reassocIndices[outerPos]);
SmallVector<ReassociationIndices> newReassocIndices = reassocIndices;
// First apply the permutation on the reassociations of the outer dims.
// For example given the permutation [1, 0], the reassociations [[0, 1], [2]]
// -> [[0], [1, 2]]
int64_t nextPos =
applyPermutationAndReindexReassoc(newReassocIndices, outerDimsPerm);
// Then add direct mapping for the inner tile dims.
for (size_t i = 0; i < innerDimsPos.size(); ++i) {
newReassocIndices.push_back({nextPos});
nextPos += 1;
}
RankedTensorType newExpandType = linalg::PackOp::inferPackedType(
expandTy, innerTileSizes, projectedInnerDimsPos, newOuterDimsPerm);
auto newExpandOp = rewriter.create<tensor::ExpandShapeOp>(
expandOp.getLoc(), newExpandType, unPackOp.getSource(),
newReassocIndices);
auto emptyOp = linalg::UnPackOp::createDestinationTensor(
rewriter, unPackOp.getLoc(), newExpandOp, unPackOp.getMixedTiles(),
projectedInnerDimsPos, newOuterDimsPerm);
auto newUnPackOp = rewriter.create<linalg::UnPackOp>(
unPackOp.getLoc(), newExpandOp.getResult(), emptyOp,
projectedInnerDimsPos, unPackOp.getMixedTiles(), newOuterDimsPerm);
rewriter.replaceOp(expandOp, newUnPackOp);
return success();
}
class PushDownUnPackOpThroughReshapeOp final
: public OpRewritePattern<linalg::UnPackOp> {
public:
PushDownUnPackOpThroughReshapeOp(MLIRContext *context,
ControlPropagationFn fun)
: OpRewritePattern<linalg::UnPackOp>(context), controlFn(std::move(fun)) {
}
LogicalResult matchAndRewrite(linalg::UnPackOp unPackOp,
PatternRewriter &rewriter) const override {
Value result = unPackOp.getResult();
// Currently only support unpack op with the single user.
if (!result.hasOneUse()) {
return failure();
}
// Currently only support static inner tile sizes.
if (llvm::any_of(unPackOp.getStaticTiles(), ShapedType::isDynamic))
return failure();
Operation *consumerOp = *result.user_begin();
return TypeSwitch<Operation *, LogicalResult>(consumerOp)
.Case([&](tensor::ExpandShapeOp op) {
return pushDownUnPackOpThroughExpandShape(unPackOp, op, rewriter,
controlFn);
})
.Default([](Operation *) { return failure(); });
}
private:
ControlPropagationFn controlFn;
};
// TODO: Relax this restriction. We should unpack a generic op also
// in the presence of multiple unpack ops as producers.
/// Return the unpacked operand, if present, for the current generic op.
static FailureOr<OpOperand *> getUnPackedOperand(GenericOp genericOp) {
OpOperand *unPackedOperand = nullptr;
for (OpOperand &operand : genericOp->getOpOperands()) {
auto unPackOp = operand.get().getDefiningOp<linalg::UnPackOp>();
if (!unPackOp)
continue;
if (unPackedOperand)
return failure();
unPackedOperand = &operand;
}
if (!unPackedOperand)
return failure();
return unPackedOperand;
}
/// Push down a linalg.unpack op through a generic op.
/// The new generic op works on packed domain; pack ops are created for input
/// and output operands. A linalg.unpack op is inserted right after the packed
/// generic. E.g.
///
/// #map = affine_map<(d0, d1, d2, d3) -> (d0, d1, d2, d3)>
///
/// %arg0 = tensor<12x2x56x56x32xf32> // packed arg.
///
/// %0 = tensor.empty() : tensor<12x56x56x64xf32>
/// %1 = linalg.unpack %arg0 outer_dims_perm = [0, 3, 1, 2]
/// inner_dims_pos = [3] inner_tiles = [32] into %0
/// %2 = linalg.generic {indexing_maps = [#map],
/// iterator_types = ["parallel", "parallel", "parallel", "parallel"]}
/// outs(%1 : tensor<12x56x56x64xf32>) {
/// ^bb0(%out : f32):
/// linalg.yield %out : f32
/// } -> tensor<12x56x56x64xf32>
///
/// will be converted to
///
/// #map = affine_map<(d0, d1, d2, d3, d4) -> (d0, d1, d2, d3, d4)>
///
/// %0 = tensor.empty() : tensor<12x56x56x64xf32>
/// %1 = linalg.generic {indexing_maps = [#map],
/// iterator_types = ["parallel", "parallel", "parallel",
/// "parallel", "parallel"]}
/// outs(%arg0 : tensor<12x2x56x56x32xf32>) {
/// ^bb0(%out : f32):
/// linalg.yield %out : f32
/// } -> tensor<12x2x56x56x32xf32>
/// %2 = linalg.unpack %1 outer_dims_perm = [0, 3, 1, 2]
/// inner_dims_pos = [3] inner_tiles = [32] into %0
///
static FailureOr<std::tuple<GenericOp, Value>>
pushDownUnPackOpThroughGenericOp(RewriterBase &rewriter, GenericOp genericOp,
ControlPropagationFn controlFn) {
if (genericOp.getNumResults() != 1)
return failure();
if (hasGatherSemantics(genericOp))
return failure();
// Collect the unPacked operand, if present.
auto maybeUnPackedOperand = getUnPackedOperand(genericOp);
if (failed(maybeUnPackedOperand))
return failure();
OpOperand *unPackedOperand = *(maybeUnPackedOperand);
// Extract packing information.
linalg::UnPackOp producerUnPackOp =
unPackedOperand->get().getDefiningOp<linalg::UnPackOp>();
assert(producerUnPackOp && "expect a valid UnPackOp");
if (!controlFn(unPackedOperand))
return failure();
auto packInfo =
getPackingInfoFromOperand(unPackedOperand, genericOp, producerUnPackOp);
if (failed(packInfo))
return failure();
// Rebuild the indexing map for the corresponding init operand.
auto [packedOutOperand, packedOutIndexingMap] =
getOrCreatePackedViewOfOperand(rewriter, genericOp.getLoc(), *packInfo,
genericOp, genericOp.getDpsInitOperand(0));
auto destPack = packedOutOperand.getDefiningOp<linalg::PackOp>();
// Forward the new tensor.empty as a destination if it is one of the following
// situations:
// 1) The dps init operand is a tensor.empty.
// 2) The dps init is a write-only operand, i.e., it is not used in the
// genericOp
Value dest = packedOutOperand;
auto initTensor =
genericOp.getDpsInitOperand(0)->get().getDefiningOp<tensor::EmptyOp>();
if (initTensor || isGenericOutsNotUsed(genericOp)) {
if (destPack)
dest = destPack.getDest();
}
// Pack the genericOp.
// pack(unpack) is foldable in this case. This is because in pushing down the
// unpack, by default we will populate an additional pack op after the unpack.
// This guarantees them to be foldable.
GenericOp newGenericOp =
packGenericOp(rewriter, genericOp, dest, packedOutIndexingMap, *packInfo,
/*isFoldableUnpackPack=*/true);
Value newResult =
newGenericOp.getTiedOpResult(newGenericOp.getDpsInitOperand(0));
// If the output is unaffected, no need to unpack.
if (!destPack)
return std::make_tuple(newGenericOp, newResult);
auto mixedTiles = destPack.getMixedTiles();
auto innerDimsPos = destPack.getInnerDimsPos();
auto outerDimsPerm = destPack.getOuterDimsPerm();
// Insert an unPackOp right after the packed generic.
Value unPackOpRes =
rewriter
.create<linalg::UnPackOp>(genericOp.getLoc(), newResult,
destPack.getSource(), innerDimsPos,
mixedTiles, outerDimsPerm)
.getResult();
return std::make_tuple(newGenericOp, unPackOpRes);
}
// Wrapper pattern that applies pushDownUnPackOpThroughGenericOp method.
struct PushDownUnPackOpThroughGenericOp : public OpRewritePattern<GenericOp> {
public:
PushDownUnPackOpThroughGenericOp(MLIRContext *context,
ControlPropagationFn fun)
: OpRewritePattern<GenericOp>(context), controlFn(std::move(fun)) {}
LogicalResult matchAndRewrite(GenericOp genericOp,
PatternRewriter &rewriter) const override {
auto genericAndRepl =
pushDownUnPackOpThroughGenericOp(rewriter, genericOp, controlFn);
if (failed(genericAndRepl))
return failure();
rewriter.replaceOp(genericOp, std::get<1>(*genericAndRepl));
return success();
}
private:
ControlPropagationFn controlFn;
};
/// Propagate a linalg.unpack operation through a tensor.pad. The idea is to
/// add as many zero padding dimensions in `high` and `low` based on the number
/// of point loops.
struct PushDownUnPackThroughPadOp : public OpRewritePattern<tensor::PadOp> {
PushDownUnPackThroughPadOp(MLIRContext *context, ControlPropagationFn fun)
: OpRewritePattern<tensor::PadOp>(context), controlFn(std::move(fun)) {}
LogicalResult matchAndRewrite(tensor::PadOp padOp,
PatternRewriter &rewriter) const override {
linalg::UnPackOp unpackOp =
padOp.getSource().getDefiningOp<linalg::UnPackOp>();
if (!unpackOp)
return failure();
if (!controlFn(&padOp.getSourceMutable()))
return failure();
Location loc = padOp.getLoc();
// Bail out if one of the padded dimension is a tiled one.
llvm::SmallBitVector paddedDims = padOp.getPaddedDims();
ArrayRef<int64_t> innerDimsPos = unpackOp.getInnerDimsPos();
llvm::SmallBitVector innerDims(paddedDims.size());
for (int64_t dim : innerDimsPos)
innerDims.flip(dim);
if (paddedDims.anyCommon(innerDims))
return failure();
Value paddingVal = padOp.getConstantPaddingValue();
if (!paddingVal)
return failure();
// If we have `outer_dims_perms` we need to adjust the padded dimensions.
ArrayRef<int64_t> outerDimsPerm = unpackOp.getOuterDimsPerm();
SmallVector<OpFoldResult> lowPad = padOp.getMixedLowPad();
SmallVector<OpFoldResult> highPad = padOp.getMixedHighPad();
if (!outerDimsPerm.empty()) {
applyPermutationToVector<OpFoldResult>(lowPad, outerDimsPerm);
applyPermutationToVector<OpFoldResult>(highPad, outerDimsPerm);
}
// Add zero padding for the point loops.
size_t pointLoopsSize = innerDimsPos.size();
lowPad.append(pointLoopsSize, rewriter.getIndexAttr(0));
highPad.append(pointLoopsSize, rewriter.getIndexAttr(0));
auto newPadOp = rewriter.create<tensor::PadOp>(
loc, /*result=*/Type(), unpackOp.getSource(), lowPad, highPad,
paddingVal, padOp.getNofold());
// Inject the linalg.unpack right after the packed padOp.
Value outputUnPack = rewriter.create<tensor::EmptyOp>(
loc, padOp.getResultType().getShape(),
padOp.getResultType().getElementType());
Value replacement = rewriter.create<linalg::UnPackOp>(
loc, newPadOp.getResult(), outputUnPack, innerDimsPos,
unpackOp.getMixedTiles(), outerDimsPerm);
rewriter.replaceOp(padOp, replacement);
return success();
}
private:
ControlPropagationFn controlFn;
};
} // namespace
void mlir::linalg::populateDataLayoutPropagationPatterns(
RewritePatternSet &patterns,
const ControlPropagationFn &controlPackUnPackPropagation) {
patterns
.insert<BubbleUpPackOpThroughGenericOpPattern, BubbleUpPackThroughPadOp,
BubbleUpPackOpThroughReshapeOp, PushDownUnPackOpThroughGenericOp,
PushDownUnPackThroughPadOp, PushDownUnPackOpThroughReshapeOp>(
patterns.getContext(), controlPackUnPackPropagation);
}