76ead96c1d
Using `LoopLikeOpInterface` as the basis for the implementation unifies all the tiling logic for both `scf.for` and `scf.forall`. The only difference is the actual loop generation. This is a follow up to https://github.com/llvm/llvm-project/pull/72178 Instead of many entry points for each loop type, the loop type is now passed as part of the options passed to the tiling method. This is a breaking change with the following changes 1) The `scf::tileUsingSCFForOp` is renamed to `scf::tileUsingSCF` 2) The `scf::tileUsingSCFForallOp` is deprecated. The same functionality is obtained by using `scf::tileUsingSCF` and setting the loop type in `scf::SCFTilingOptions` passed into this method to `scf::SCFTilingOptions::LoopType::ForallOp` (using the `setLoopType` method). 3) The `scf::tileConsumerAndFusedProducerGreedilyUsingSCFForOp` is renamed to `scf::tileConsumerAndFuseProducerUsingSCF`. The use of the `controlFn` in `scf::SCFTileAndFuseOptions` allows implementing any strategy with the default callback implemeting the greedy fusion. 4) The `scf::SCFTilingResult` and `scf::SCFTileAndFuseResult` now use `SmallVector<LoopLikeOpInterface>`. 5) To make `scf::ForallOp` implement the parts of `LoopLikeOpInterface` needed, the `getOutputBlockArguments()` method is replaced with `getRegionIterArgs()` These changes now bring the tiling and fusion capabilities using `scf.forall` on par with what was already supported by `scf.for`
1138 lines
49 KiB
C++
1138 lines
49 KiB
C++
//===- Tiling.cpp - Implementation of tiling using TilingInterface -------===//
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//
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// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
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// See https://llvm.org/LICENSE.txt for license information.
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// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
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//
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//===----------------------------------------------------------------------===//
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//
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// This file implements the tiling using TilingInterface.
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//
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//===----------------------------------------------------------------------===//
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#include "mlir/Dialect/SCF/Transforms/TileUsingInterface.h"
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#include "mlir/Dialect/Affine/IR/AffineOps.h"
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#include "mlir/Dialect/Arith/IR/Arith.h"
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#include "mlir/Dialect/Arith/Utils/Utils.h"
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#include "mlir/Dialect/Func/IR/FuncOps.h"
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#include "mlir/Dialect/SCF/Utils/Utils.h"
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#include "mlir/Dialect/Tensor/IR/Tensor.h"
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#include "mlir/Dialect/Utils/IndexingUtils.h"
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#include "mlir/IR/Matchers.h"
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#include "mlir/IR/PatternMatch.h"
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#include "mlir/Interfaces/DestinationStyleOpInterface.h"
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#include "mlir/Interfaces/TilingInterface.h"
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#include "llvm/ADT/TypeSwitch.h"
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#include "llvm/Support/Debug.h"
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#include <optional>
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#define DEBUG_TYPE "tile-using-interface"
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using namespace mlir;
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scf::SCFTilingOptions &
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scf::SCFTilingOptions::setTileSizes(ArrayRef<OpFoldResult> ts) {
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assert(!tileSizeComputationFunction && "tile sizes already set");
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auto tileSizes = llvm::to_vector(ts);
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tileSizeComputationFunction = [tileSizes](OpBuilder &b, Operation *op) {
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return tileSizes;
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};
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return *this;
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}
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/// Helper method to adjust the interchange vector to match the iteration
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/// domain.
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static SmallVector<int64_t>
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fillInterchangeVector(ArrayRef<int64_t> interchangeVector,
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size_t iterationDomainSize) {
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SmallVector<int64_t> filledVector = llvm::to_vector(interchangeVector);
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if (filledVector.size() < iterationDomainSize) {
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auto range = llvm::seq<int64_t>(filledVector.size(), iterationDomainSize);
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filledVector.append(range.begin(), range.end());
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}
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if (filledVector.size() > iterationDomainSize)
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filledVector.resize(iterationDomainSize);
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return filledVector;
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}
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//===----------------------------------------------------------------------===//
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// tileUsingSCF implementation.
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//===----------------------------------------------------------------------===//
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// Check if `stride` evenly divides the trip count `size - offset`.
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static bool tileDividesIterationDomain(Range loopRange) {
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std::optional<int64_t> offsetAsInt = getConstantIntValue(loopRange.offset);
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if (!offsetAsInt)
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return false;
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std::optional<int64_t> sizeAsInt = getConstantIntValue(loopRange.size);
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if (!sizeAsInt)
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return false;
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std::optional<int64_t> strideAsInt = getConstantIntValue(loopRange.stride);
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if (!strideAsInt)
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return false;
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return ((sizeAsInt.value() - offsetAsInt.value()) % strideAsInt.value() == 0);
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}
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/// Returns the bounded tile size given the current `iv`, `loopRange` and
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/// `tileSize`, i.e., `min(tileSize, range.end() - iv)`.
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static OpFoldResult getBoundedTileSize(OpBuilder &b, Location loc,
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Range loopRange, Value iv,
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OpFoldResult tileSize) {
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std::optional<int64_t> ts = getConstantIntValue(tileSize);
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if (ts && ts.value() == 1)
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return tileSize;
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if (tileDividesIterationDomain(
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Range{loopRange.offset, loopRange.size, tileSize}))
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return tileSize;
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// The tile size to use (to avoid out of bounds access) is minimum of
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// `tileSize` and `ub - iv`, where `iv` is the induction variable of the tiled
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// loop.
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AffineExpr s0, s1, d0;
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bindDims(b.getContext(), d0);
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bindSymbols(b.getContext(), s0, s1);
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AffineMap minMap = AffineMap::get(1, 2, {s0, s1 - d0}, b.getContext());
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Value size = getValueOrCreateConstantIndexOp(b, loc, loopRange.size);
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return affine::makeComposedFoldedAffineMin(
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b, loc, minMap, SmallVector<OpFoldResult>{iv, tileSize, size});
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}
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/// A function that allows returning additional yielded values during
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/// `yieldTiledValuesAndReplace`.
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/// - `ivs` induction variable for the loop.
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/// - `newBbArgs` basic block arguments corresponding to newly added iter_args.
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/// - `tiledValues` the tiled values to return. Must be of same size as
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/// `newbbArgs`, each element of this array is inserted into the corresponding
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/// element in `newbbArgs`.
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/// - `resultOffsets` is of the same size as `tiledValues` and represents
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/// the offsets to use when inserting corresponding element from `tiledValues`
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/// into the element from `newBbArgs`.
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/// - `resultSizes` is of the same size as `tiledValues` and represents
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/// the size of the corresponding element from `tiledValues` inserted into
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/// the element from `newBbArgs`.
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/// In case the method needs to return `failure()` the method is expected
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/// to clean up any inserted operations.
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using YieldTiledValuesFn = std::function<LogicalResult(
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RewriterBase &rewriter, Location loc, ValueRange ivs, ValueRange newBbArgs,
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SmallVector<Value> &tiledValues,
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SmallVector<SmallVector<OpFoldResult>> &resultOffsets,
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SmallVector<SmallVector<OpFoldResult>> &resultSizes)>;
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/// Clones the operation and updates the destination if the operation
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/// implements the `DestinationStyleOpInterface`.
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static Operation *cloneOpAndUpdateDestinationArgs(RewriterBase &rewriter,
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Operation *op,
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ValueRange newDestArgs) {
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Operation *clonedOp = rewriter.clone(*op);
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if (newDestArgs.empty())
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return clonedOp;
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if (auto destinationStyleOp = dyn_cast<DestinationStyleOpInterface>(clonedOp))
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destinationStyleOp.getDpsInitsMutable().assign(newDestArgs);
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return clonedOp;
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}
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/// Generate the tile-loop nest using `scf.for` operation.
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/// - `loopRanges` specifies the lb, ub and step of the untiled iteration space.
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/// - `tileSizes` is the tile sizes to use. Zero represent untiled loops.
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/// - `destinationTensors` are the init values to use for the outer most loop.
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/// - `yieldTiledValuesFn` is called to generated the loop body of the inner
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/// most
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/// loop.
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/// - `loops` is an in-out parameter into which the generated loops are
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/// populated.
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static LogicalResult generateLoopNestUsingForOp(
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RewriterBase &rewriter, Location loc, ArrayRef<Range> loopRanges,
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ArrayRef<OpFoldResult> tileSizes, ValueRange destinationTensors,
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YieldTiledValuesFn yieldTiledValuesFn,
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SmallVector<LoopLikeOpInterface> &loops) {
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assert(!loopRanges.empty() && "unexpected empty loop ranges");
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assert(loopRanges.size() == tileSizes.size() &&
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"expected as many tile sizes as loop ranges");
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OpBuilder::InsertionGuard guard(rewriter);
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SmallVector<Value> ivs;
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for (auto [loopRange, tileSize] : llvm::zip_equal(loopRanges, tileSizes)) {
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// No loops if tile size is zero. Set offset and size to the loop
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// offset and size.
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if (isConstantIntValue(tileSize, 0))
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continue;
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Value lb = getValueOrCreateConstantIndexOp(rewriter, loc, loopRange.offset);
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Value ub = getValueOrCreateConstantIndexOp(rewriter, loc, loopRange.size);
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Value step = getValueOrCreateConstantIndexOp(rewriter, loc, tileSize);
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auto loop =
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rewriter.create<scf::ForOp>(loc, lb, ub, step, destinationTensors,
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[](OpBuilder &bodyBuilder, Location bodyLoc,
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Value iv, ValueRange /*iterArgs*/) {});
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loops.push_back(loop);
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ivs.push_back(loop.getInductionVar());
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rewriter.setInsertionPointToEnd(loop.getBody());
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destinationTensors = loop.getRegionIterArgs();
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}
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SmallVector<Value> tiledResults;
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SmallVector<SmallVector<OpFoldResult>> resultOffsets, resultSizes;
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if (failed(yieldTiledValuesFn(rewriter, loc, ivs, destinationTensors,
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tiledResults, resultOffsets, resultSizes))) {
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return rewriter.notifyMatchFailure(
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loc, "failed to generate inner tile loop body");
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}
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if (loops.empty())
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return success();
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// 6. Yield all the results of the tiled operation.
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SmallVector<Value> yieldedValues;
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for (auto [tiledValue, destinationTensor, resultOffset, resultSize] :
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llvm::zip_equal(tiledResults, destinationTensors, resultOffsets,
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resultSizes)) {
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SmallVector<OpFoldResult> resultStride(resultOffset.size(),
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rewriter.getIndexAttr(1));
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auto insertSlice = rewriter.create<tensor::InsertSliceOp>(
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loc, tiledValue, destinationTensor, resultOffset, resultSize,
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resultStride);
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yieldedValues.push_back(insertSlice);
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}
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rewriter.create<scf::YieldOp>(loc, yieldedValues);
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// Add the scf.yield operations for all the outer loops.
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for (auto [outerLoop, innerLoop] :
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llvm::zip_equal(MutableArrayRef(loops).drop_back(),
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MutableArrayRef(loops).drop_front())) {
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rewriter.setInsertionPointToEnd(
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cast<scf::ForOp>(outerLoop.getOperation()).getBody());
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rewriter.create<scf::YieldOp>(outerLoop.getLoc(), innerLoop->getResults());
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}
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return success();
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}
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/// Generate the tile-loop nest using `scf.forall` operation.
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/// - `loopRanges` specifies the lb, ub and step of the untiled iteration space.
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/// - `tileSizes` is the tile sizes to use. Zero represent untiled loops.
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/// - `destinationTensors` are the init values to use for the outer most loop.
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/// - `mappingVector` is the mapping attributes to use for loop construction.
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/// Can be empty.
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/// - `yieldTiledValuesFn` is called to generated the loop body of the inner
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/// most
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/// loop.
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/// - `loops` is an in-out parameter into which the generated loops are
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/// populated.
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static LogicalResult generateLoopNestUsingForallOp(
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RewriterBase &rewriter, Location loc, ArrayRef<Range> loopRanges,
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ArrayRef<OpFoldResult> tileSizes, ArrayRef<Attribute> mappingVector,
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ValueRange destinationTensors, YieldTiledValuesFn tiledBodyFn,
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SmallVector<LoopLikeOpInterface> &loops) {
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SmallVector<OpFoldResult> lbs, ubs, steps;
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assert(!loopRanges.empty() && "unexpected empty loop ranges");
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assert(loopRanges.size() == tileSizes.size() &&
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"expected as many tile sizes as loop ranges");
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OpBuilder::InsertionGuard guard(rewriter);
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SmallVector<OpFoldResult> offsets(loopRanges.size()),
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sizes(loopRanges.size());
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for (auto [tileSize, loopRange] : llvm::zip_equal(tileSizes, loopRanges)) {
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if (isConstantIntValue(tileSize, 0))
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continue;
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lbs.push_back(loopRange.offset);
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ubs.push_back(loopRange.size);
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steps.push_back(tileSize);
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}
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assert(!lbs.empty() && "Expected at least one loop range");
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std::optional<ArrayAttr> mappingAttr;
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if (!mappingVector.empty())
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mappingAttr = rewriter.getArrayAttr(mappingVector);
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auto forallOp = rewriter.create<scf::ForallOp>(
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loc, lbs, ubs, steps, destinationTensors, mappingAttr);
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loops.push_back(forallOp);
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rewriter.setInsertionPoint(forallOp.getTerminator());
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destinationTensors = forallOp.getRegionOutArgs();
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SmallVector<Value> tiledResults;
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SmallVector<SmallVector<OpFoldResult>> resultOffsets, resultSizes;
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if (failed(tiledBodyFn(rewriter, loc, forallOp.getInductionVars(),
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destinationTensors, tiledResults, resultOffsets,
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resultSizes)))
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return rewriter.notifyMatchFailure(loc, "failed to generate loop body");
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rewriter.setInsertionPointToEnd(forallOp.getTerminator().getBody());
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for (auto [tiledValue, destinationTensor, resultOffset, resultSize] :
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llvm::zip_equal(tiledResults, destinationTensors, resultOffsets,
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resultSizes)) {
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SmallVector<OpFoldResult> resultStride(resultOffset.size(),
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rewriter.getIndexAttr(1));
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rewriter.create<tensor::ParallelInsertSliceOp>(
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loc, tiledValue, destinationTensor, resultOffset, resultSize,
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resultStride);
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}
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return success();
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}
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/// Generate the tile-loop nest using the loop construct specifed in `options`.
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/// - `options`: Tiling options specified.
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/// - `loopRanges` specifies the lb, ub and step of the untiled iteration space.
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/// - `tileSizes` is the tile sizes to use. Zero represent untiled loops.
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/// - `destinationTensors` are the init values to use for the outer most loop.
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/// - `yieldTiledValuesFn` is called to generated the loop body of the inner
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/// most
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/// loop.
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/// - `loops` is an in-out parameter into which the generated loops are
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/// populated.
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static LogicalResult generateLoopNest(RewriterBase &rewriter, Location loc,
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const scf::SCFTilingOptions &options,
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ArrayRef<Range> loopRanges,
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ArrayRef<OpFoldResult> tileSizes,
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ValueRange destinationTensors,
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YieldTiledValuesFn tiledBodyFn,
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SmallVector<LoopLikeOpInterface> &loops) {
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// If the tile sizes are all zero, no loops are generated. Just call the
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// callback function to handle untiled case.
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if (llvm::all_of(tileSizes, isZeroIndex)) {
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SmallVector<Value> tiledResults;
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SmallVector<SmallVector<OpFoldResult>> resultOffsets, resultSizes;
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return tiledBodyFn(rewriter, loc, ValueRange{}, destinationTensors,
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tiledResults, resultOffsets, resultSizes);
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}
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if (options.loopType == scf::SCFTilingOptions::LoopType::ForOp) {
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return generateLoopNestUsingForOp(rewriter, loc, loopRanges, tileSizes,
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destinationTensors, tiledBodyFn, loops);
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}
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if (options.loopType == scf::SCFTilingOptions::LoopType::ForallOp) {
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return generateLoopNestUsingForallOp(
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rewriter, loc, loopRanges, tileSizes, options.mappingVector,
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destinationTensors, tiledBodyFn, loops);
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}
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return rewriter.notifyMatchFailure(loc, "unhandled loop type");
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}
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/// Append the specified additional `newInitOperands` operands to the
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/// loops existing `init` operands (or similar), and replace `loopOp` with
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/// the new loop that has the additional init operands. The loop body of
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/// this loop is moved over to the new loop. `yieldTiledValuesFn`
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/// is called to get the new tiled values returned, and the offset
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/// and sizes at which the tiled value is inserted into the
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/// new region iter_args that correspond to the newly added init operands.
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template <typename LoopType>
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FailureOr<LoopLikeOpInterface>
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yieldTiledValuesAndReplaceLoop(LoopType loopOp, RewriterBase &rewriter,
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ValueRange newInitOperands,
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YieldTiledValuesFn yieldTiledValuesFn) {
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return rewriter.notifyMatchFailure(loopOp, "unhandled loop type");
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}
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/// Implementation of `yieldTiledValuesAndReplaceLoop` for `scf.for`.
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template <>
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FailureOr<LoopLikeOpInterface> yieldTiledValuesAndReplaceLoop<scf::ForOp>(
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scf::ForOp loopOp, RewriterBase &rewriter, ValueRange newInitOperands,
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YieldTiledValuesFn yieldTiledValuesFn) {
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OpBuilder::InsertionGuard g(rewriter);
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Location loc = loopOp.getLoc();
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rewriter.setInsertionPoint(loopOp);
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auto inits = llvm::to_vector(loopOp.getInitArgs());
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inits.append(newInitOperands.begin(), newInitOperands.end());
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auto newLoop = rewriter.create<scf::ForOp>(
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loc, loopOp.getLowerBound(), loopOp.getUpperBound(), loopOp.getStep(),
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inits, [](OpBuilder &, Location, Value, ValueRange) {});
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// Move the loop body to the new op.
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Block *loopBody = loopOp.getBody();
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Block *newLoopBody = newLoop.getBody();
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rewriter.mergeBlocks(
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loopBody, newLoopBody,
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newLoopBody->getArguments().take_front(loopBody->getNumArguments()));
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auto yieldOp = cast<scf::YieldOp>(newLoopBody->getTerminator());
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rewriter.setInsertionPoint(yieldOp);
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SmallVector<Value> tiledValues;
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SmallVector<SmallVector<OpFoldResult>> resultOffsets, resultSizes;
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ValueRange newRegionIterArgs =
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newLoop.getRegionIterArgs().take_back(newInitOperands.size());
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if (failed(yieldTiledValuesFn(rewriter, loc, newLoop.getInductionVar(),
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newRegionIterArgs, tiledValues, resultOffsets,
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resultSizes))) {
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rewriter.eraseOp(newLoop);
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return rewriter.notifyMatchFailure(loopOp, "failed to get tiled values");
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}
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SmallVector<Value> newYieldValues = llvm::to_vector(yieldOp.getOperands());
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for (auto [tiledValue, regionIterArg, resultOffset, resultSize] :
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llvm::zip_equal(tiledValues, newRegionIterArgs, resultOffsets,
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resultSizes)) {
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SmallVector<OpFoldResult> resultStride(resultOffset.size(),
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rewriter.getIndexAttr(1));
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Value insert = rewriter.create<tensor::InsertSliceOp>(
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yieldOp->getLoc(), tiledValue, regionIterArg, resultOffset, resultSize,
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resultStride);
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newYieldValues.push_back(insert);
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}
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rewriter.replaceOpWithNewOp<scf::YieldOp>(yieldOp, newYieldValues);
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rewriter.replaceOp(loopOp,
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newLoop->getResults().take_front(loopOp.getNumResults()));
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return cast<LoopLikeOpInterface>(newLoop.getOperation());
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}
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/// Implementation of `yieldTiledValuesAndReplaceLoop` for `scf.forall`
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template <>
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FailureOr<LoopLikeOpInterface> yieldTiledValuesAndReplaceLoop<scf::ForallOp>(
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scf::ForallOp loopOp, RewriterBase &rewriter, ValueRange newInitOperands,
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YieldTiledValuesFn yieldTiledValuesFn) {
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OpBuilder::InsertionGuard g(rewriter);
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Location loc = loopOp.getLoc();
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rewriter.setInsertionPoint(loopOp);
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auto inits = llvm::to_vector(loopOp.getOutputs());
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inits.append(newInitOperands.begin(), newInitOperands.end());
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auto newLoop = rewriter.create<scf::ForallOp>(
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loc, loopOp.getMixedLowerBound(), loopOp.getMixedUpperBound(),
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loopOp.getMixedStep(), inits, loopOp.getMapping(),
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[](OpBuilder &, Location, ValueRange) {});
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// Move the region of the current block to the newly created op.
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Block *loopBody = loopOp.getBody();
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Block *newLoopBody = newLoop.getBody();
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rewriter.mergeBlocks(
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loopBody, newLoopBody,
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newLoopBody->getArguments().take_front(loopBody->getNumArguments()));
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auto terminator = cast<scf::InParallelOp>(newLoopBody->getTerminator());
|
|
rewriter.setInsertionPoint(terminator);
|
|
SmallVector<Value> tiledValues;
|
|
SmallVector<SmallVector<OpFoldResult>> resultOffsets, resultSizes;
|
|
ValueRange regionIterArgs =
|
|
newLoop.getRegionIterArgs().take_back(newInitOperands.size());
|
|
if (failed(yieldTiledValuesFn(rewriter, loc, newLoop.getInductionVars(),
|
|
regionIterArgs, tiledValues, resultOffsets,
|
|
resultSizes))) {
|
|
rewriter.eraseOp(newLoop);
|
|
return rewriter.notifyMatchFailure(loopOp,
|
|
"failed to get yielded tiled values");
|
|
}
|
|
|
|
// Update the terminator.
|
|
rewriter.setInsertionPointToEnd(terminator.getBody());
|
|
|
|
for (auto [tiledValue, iterArg, resultOffset, resultSize] : llvm::zip_equal(
|
|
tiledValues, regionIterArgs, resultOffsets, resultSizes)) {
|
|
SmallVector<OpFoldResult> resultStride(resultOffset.size(),
|
|
rewriter.getIndexAttr(1));
|
|
rewriter.create<tensor::ParallelInsertSliceOp>(
|
|
terminator.getLoc(), tiledValue, iterArg, resultOffset, resultSize,
|
|
resultStride);
|
|
}
|
|
|
|
rewriter.replaceOp(loopOp,
|
|
newLoop->getResults().take_front(loopOp.getNumResults()));
|
|
return cast<LoopLikeOpInterface>(newLoop.getOperation());
|
|
}
|
|
|
|
/// Implementation of `yieldTiledValuesAndReplaceLoop` for
|
|
/// `LoopLikeOpInterface`, that just dispatches to the implementation for each
|
|
/// supported loop type.
|
|
FailureOr<LoopLikeOpInterface> yieldTiledValuesAndReplaceLoop(
|
|
LoopLikeOpInterface loopLikeOp, RewriterBase &rewriter,
|
|
ValueRange newInitOperands, YieldTiledValuesFn yieldTiledValuesFn) {
|
|
return TypeSwitch<Operation *, FailureOr<LoopLikeOpInterface>>(
|
|
loopLikeOp.getOperation())
|
|
.Case<scf::ForOp, scf::ForallOp>(
|
|
[&](auto loopOp) -> FailureOr<LoopLikeOpInterface> {
|
|
return yieldTiledValuesAndReplaceLoop(
|
|
loopOp, rewriter, newInitOperands, yieldTiledValuesFn);
|
|
})
|
|
.Default([&](auto loopOp) -> FailureOr<LoopLikeOpInterface> {
|
|
return rewriter.notifyMatchFailure(loopOp, "unhandled loop type");
|
|
});
|
|
}
|
|
|
|
/// Method to add new init values to a loop nest. Updates `loops` in-place with
|
|
/// new loops that use the `newInitValues`.
|
|
/// The outer-loops are updated to yield the new result values of the inner
|
|
/// loop. For the innermost loop, the call back `getNewYields` is invoked to get
|
|
/// the additional values to yield form the innermost loop.
|
|
static LogicalResult addInitOperandsToLoopNest(
|
|
RewriterBase &rewriter, MutableArrayRef<LoopLikeOpInterface> loops,
|
|
ValueRange newInitValues, YieldTiledValuesFn getNewTiledYieldsFn) {
|
|
SmallVector<scf::ForOp> newLoops;
|
|
if (loops.empty())
|
|
return success();
|
|
OpBuilder::InsertionGuard g(rewriter);
|
|
rewriter.setInsertionPoint(loops.front());
|
|
|
|
SmallVector<Value> ivs;
|
|
for (auto &loop : loops.drop_back()) {
|
|
rewriter.setInsertionPoint(loop);
|
|
|
|
// if loops.size() > 1 we assume that scf.for is used for the loops.
|
|
auto forLoop = cast<scf::ForOp>(loop.getOperation());
|
|
|
|
// Create a new loop with the new init values for this loop.
|
|
SmallVector<Value> newInits = llvm::to_vector(forLoop.getInitArgs());
|
|
newInits.append(newInitValues.begin(), newInitValues.end());
|
|
auto newLoop = rewriter.create<scf::ForOp>(
|
|
forLoop.getLoc(), forLoop.getLowerBound(), forLoop.getUpperBound(),
|
|
forLoop.getStep(), newInits,
|
|
[&](OpBuilder &b, Location loc, Value iv, ValueRange iterArgs) {});
|
|
|
|
// Merge the body of the new loop with the body of the old loops.
|
|
SmallVector<Value> sourceBlockArgs;
|
|
sourceBlockArgs.push_back(newLoop.getInductionVar());
|
|
auto newRegionIterArgs = newLoop.getRegionIterArgs();
|
|
sourceBlockArgs.append(
|
|
newRegionIterArgs.begin(),
|
|
std::next(newRegionIterArgs.begin(), forLoop.getNumResults()));
|
|
rewriter.mergeBlocks(forLoop.getBody(), newLoop.getBody(), sourceBlockArgs);
|
|
rewriter.replaceOp(
|
|
forLoop, newLoop.getResults().take_front(forLoop.getNumResults()));
|
|
loop = newLoop;
|
|
ivs.push_back(newLoop.getInductionVar());
|
|
newInitValues = newLoop.getRegionIterArgs().take_back(newInitValues.size());
|
|
}
|
|
|
|
// Update the loop body of the innermost loop to get new yield values.
|
|
LoopLikeOpInterface innerMostLoop = loops.back();
|
|
FailureOr<LoopLikeOpInterface> newInnerMostLoop =
|
|
yieldTiledValuesAndReplaceLoop(innerMostLoop, rewriter, newInitValues,
|
|
getNewTiledYieldsFn);
|
|
|
|
if (failed(newInnerMostLoop))
|
|
return innerMostLoop.emitOpError("failed to return additional yields");
|
|
loops.back() = newInnerMostLoop.value();
|
|
|
|
// Make all other loops except the innermost loops yield the values returned
|
|
// by the inner loop.
|
|
for (auto [outerLoop, innerLoop] :
|
|
llvm::zip_equal(loops.drop_back(), loops.drop_front())) {
|
|
// Again assume that all the outer loops are scf.for operations.
|
|
auto outerForLoop = cast<scf::ForOp>(outerLoop);
|
|
auto outerLoopYield =
|
|
cast<scf::YieldOp>(outerForLoop.getBody()->getTerminator());
|
|
SmallVector<Value> newYields =
|
|
llvm::to_vector(outerLoopYield.getOperands());
|
|
ValueRange additionalYields =
|
|
innerLoop->getResults().take_back(newInitValues.size());
|
|
newYields.append(additionalYields.begin(), additionalYields.end());
|
|
rewriter.setInsertionPoint(outerLoopYield);
|
|
rewriter.replaceOpWithNewOp<scf::YieldOp>(outerLoopYield, newYields);
|
|
}
|
|
return success();
|
|
}
|
|
|
|
/// Implementation of tiling transformation of `op` that implements the
|
|
/// `TilingInterface` using `scf.for` to iterate over the tiles.
|
|
FailureOr<scf::SCFTilingResult>
|
|
mlir::scf::tileUsingSCF(RewriterBase &rewriter, TilingInterface op,
|
|
const scf::SCFTilingOptions &options) {
|
|
OpBuilder::InsertionGuard guard(rewriter);
|
|
rewriter.setInsertionPointAfter(op);
|
|
|
|
if (!options.tileSizeComputationFunction) {
|
|
return rewriter.notifyMatchFailure(
|
|
op, "missing tile size computation function");
|
|
}
|
|
|
|
// 1. Get the range of the loops that are represented by the operation.
|
|
SmallVector<Range> iterationDomain = op.getIterationDomain(rewriter);
|
|
size_t numLoops = iterationDomain.size();
|
|
|
|
// 2. Materialize the tile sizes. Enforce the convention that "tiling by zero"
|
|
// skips tiling a particular dimension. This convention is significantly
|
|
// simpler to handle instead of adjusting affine maps to account for missing
|
|
// dimensions.
|
|
SmallVector<OpFoldResult> tileSizes =
|
|
options.tileSizeComputationFunction(rewriter, op);
|
|
if (tileSizes.size() < iterationDomain.size()) {
|
|
auto zero = rewriter.getIndexAttr(0);
|
|
tileSizes.append(numLoops - tileSizes.size(), zero);
|
|
}
|
|
|
|
// 3. If there is an interchange specified, permute the iteration domain and
|
|
// the tile sizes.
|
|
SmallVector<int64_t> interchangeVector;
|
|
if (!options.interchangeVector.empty()) {
|
|
interchangeVector = fillInterchangeVector(options.interchangeVector,
|
|
iterationDomain.size());
|
|
}
|
|
if (!interchangeVector.empty()) {
|
|
if (!isPermutationVector(interchangeVector)) {
|
|
return rewriter.notifyMatchFailure(
|
|
op, "invalid intechange vector, not a permutation of the entire "
|
|
"iteration space");
|
|
}
|
|
|
|
applyPermutationToVector(iterationDomain, interchangeVector);
|
|
applyPermutationToVector(tileSizes, interchangeVector);
|
|
}
|
|
|
|
FailureOr<TilingResult> tilingResult;
|
|
// 4. Define the lambda function used later to generate the body of the
|
|
// innermost tiled loop.
|
|
YieldTiledValuesFn innerYieldTiledValuesFn =
|
|
[&](RewriterBase &rewriter, Location loc, ValueRange ivs,
|
|
ValueRange regionIterArgs, SmallVector<Value> &tiledResults,
|
|
SmallVector<SmallVector<OpFoldResult>> &resultOffsets,
|
|
SmallVector<SmallVector<OpFoldResult>> &resultSizes)
|
|
-> LogicalResult {
|
|
// 4a. Compute the `offsets` and `sizes` to use for tiling.
|
|
SmallVector<OpFoldResult> offsets, sizes;
|
|
{
|
|
int materializedLoopNum = 0;
|
|
for (auto [tileSize, loopRange] :
|
|
llvm::zip_equal(tileSizes, iterationDomain)) {
|
|
if (isConstantIntValue(tileSize, 0)) {
|
|
offsets.push_back(loopRange.offset);
|
|
sizes.push_back(loopRange.size);
|
|
continue;
|
|
}
|
|
Value iv = ivs[materializedLoopNum++];
|
|
offsets.push_back(iv);
|
|
sizes.push_back(
|
|
getBoundedTileSize(rewriter, loc, loopRange, iv, tileSize));
|
|
}
|
|
}
|
|
|
|
// 4b. If interchange was provided, apply inverse of the interchange
|
|
// to get back the offsets/sizes in the order to be specified.
|
|
if (!interchangeVector.empty()) {
|
|
auto inversePermutation = invertPermutationVector(interchangeVector);
|
|
applyPermutationToVector(offsets, inversePermutation);
|
|
applyPermutationToVector(sizes, inversePermutation);
|
|
}
|
|
|
|
// 5. Generate the tiled implementation within the inner most loop.
|
|
|
|
// 5a. Clone the operation within the loop body.
|
|
auto clonedOp = cast<TilingInterface>(
|
|
cloneOpAndUpdateDestinationArgs(rewriter, op, regionIterArgs));
|
|
|
|
// 5b. Early return cloned op if tiling is not happening. We can not return
|
|
// the original op because it could lead to
|
|
// `rewriter.replaceOp(op, op->getResults())` and users would get crash.
|
|
if (llvm::all_of(tileSizes, isZeroIndex)) {
|
|
tiledResults.append(clonedOp->result_begin(), clonedOp->result_end());
|
|
tilingResult =
|
|
TilingResult{/*tiledOps=*/{clonedOp}, clonedOp->getResults()};
|
|
return success();
|
|
}
|
|
|
|
// 5c. Tile the cloned operation.
|
|
tilingResult = clonedOp.getTiledImplementation(rewriter, offsets, sizes);
|
|
if (failed(tilingResult)) {
|
|
rewriter.eraseOp(clonedOp);
|
|
return op.emitOpError("faild to tile operation");
|
|
}
|
|
|
|
// 5d. Delete the cloned operation.
|
|
rewriter.eraseOp(clonedOp);
|
|
|
|
// 5e. Compute the offsets at which the result values are to be inserted
|
|
// back into its destinations.
|
|
for (auto [index, tiledValue] :
|
|
llvm::enumerate(tilingResult->tiledValues)) {
|
|
tiledResults.push_back(tiledValue);
|
|
SmallVector<OpFoldResult> resultOffset, resultSize;
|
|
if (failed(op.getResultTilePosition(rewriter, index, offsets, sizes,
|
|
resultOffset, resultSize))) {
|
|
for (auto op : tilingResult->tiledOps) {
|
|
rewriter.eraseOp(op);
|
|
}
|
|
return rewriter.notifyMatchFailure(
|
|
op, "failed to get slice of result produced");
|
|
}
|
|
resultOffsets.emplace_back(std::move(resultOffset));
|
|
resultSizes.emplace_back(std::move(resultSize));
|
|
}
|
|
|
|
return success();
|
|
};
|
|
|
|
// 6. Find the destination tensors to use for the operation.
|
|
SmallVector<Value> destinationTensors;
|
|
if (failed(tensor::getOrCreateDestinations(rewriter, op.getLoc(), op,
|
|
destinationTensors))) {
|
|
return rewriter.notifyMatchFailure(op,
|
|
"unable to create destination tensors");
|
|
}
|
|
|
|
// 7. Generate the tiled loops nest using the callback defined above.
|
|
SmallVector<LoopLikeOpInterface> loops;
|
|
if (failed(generateLoopNest(rewriter, op.getLoc(), options, iterationDomain,
|
|
tileSizes, destinationTensors,
|
|
innerYieldTiledValuesFn, loops)))
|
|
return op.emitOpError("failed to generate tiling loops");
|
|
assert(succeeded(tilingResult) &&
|
|
"expected tiling result to be computed after loop generation");
|
|
|
|
// If loops are empty, the tiled op is used as the replacement for the untiled
|
|
// op.
|
|
if (loops.empty()) {
|
|
return scf::SCFTilingResult{tilingResult->tiledOps, loops,
|
|
tilingResult->tiledValues};
|
|
}
|
|
|
|
SmallVector<Value> replacements = llvm::map_to_vector(
|
|
loops.front()->getResults(), [](OpResult r) -> Value { return r; });
|
|
return scf::SCFTilingResult{tilingResult->tiledOps, loops, replacements};
|
|
}
|
|
|
|
FailureOr<scf::SCFReductionTilingResult>
|
|
mlir::scf::tileReductionUsingScf(RewriterBase &b,
|
|
PartialReductionOpInterface op,
|
|
ArrayRef<OpFoldResult> tileSizes) {
|
|
Location loc = op.getLoc();
|
|
// Ops implementing PartialReductionOpInterface are expected to implement
|
|
// TilingInterface.
|
|
auto tilingInterfaceOp = cast<TilingInterface>(op.getOperation());
|
|
SmallVector<Range> iterationDomain = tilingInterfaceOp.getIterationDomain(b);
|
|
auto tileSizesVector = llvm::to_vector(tileSizes);
|
|
if (tileSizesVector.size() < iterationDomain.size()) {
|
|
auto zero = b.getIndexAttr(0);
|
|
tileSizesVector.append(iterationDomain.size() - tileSizesVector.size(),
|
|
zero);
|
|
}
|
|
if (op->getNumResults() != 1)
|
|
return b.notifyMatchFailure(
|
|
op, "don't support ops with multiple results for now");
|
|
SmallVector<utils::IteratorType> iterators =
|
|
tilingInterfaceOp.getLoopIteratorTypes();
|
|
|
|
SmallVector<int> reductionDims;
|
|
for (auto [idx, iteratorType] :
|
|
llvm::enumerate(tilingInterfaceOp.getLoopIteratorTypes())) {
|
|
if (iteratorType == utils::IteratorType::reduction)
|
|
reductionDims.push_back(idx);
|
|
}
|
|
|
|
// 2. create the inital tensor value.
|
|
FailureOr<Operation *> identityTensor =
|
|
op.generateInitialTensorForPartialReduction(b, loc, tileSizesVector,
|
|
reductionDims);
|
|
if (failed(identityTensor))
|
|
return b.notifyMatchFailure(op,
|
|
"cannot create a tensor of identity value.");
|
|
|
|
// 3. Define the callback to use for generating the inner most tile loop body.
|
|
Operation *parallelOp = nullptr;
|
|
auto innerYieldTiledValuesFn =
|
|
[&](RewriterBase &rewriter, Location loc, ValueRange ivs,
|
|
ValueRange regionIterArgs, SmallVector<Value> &tiledResult,
|
|
SmallVector<SmallVector<OpFoldResult>> &resultOffsets,
|
|
SmallVector<SmallVector<OpFoldResult>> &resultSizes)
|
|
-> LogicalResult {
|
|
SmallVector<OpFoldResult> offsets, sizes;
|
|
{
|
|
int materializedLoopNum = 0;
|
|
for (auto [tileSize, loopRange] :
|
|
llvm::zip_equal(tileSizesVector, iterationDomain)) {
|
|
if (isConstantIntValue(tileSize, 0)) {
|
|
offsets.push_back(loopRange.offset);
|
|
sizes.push_back(loopRange.size);
|
|
continue;
|
|
}
|
|
Value iv = ivs[materializedLoopNum++];
|
|
offsets.push_back(iv);
|
|
sizes.push_back(
|
|
getBoundedTileSize(rewriter, loc, loopRange, iv, tileSize));
|
|
}
|
|
}
|
|
|
|
// 4a. Clone the operation.
|
|
auto clonedOp = cast<PartialReductionOpInterface>(
|
|
cloneOpAndUpdateDestinationArgs(b, op, regionIterArgs));
|
|
|
|
// 4b. Tile the cloned operation.
|
|
parallelOp = clonedOp.tileToPartialReduction(b, loc, regionIterArgs,
|
|
offsets, sizes, reductionDims);
|
|
// 4c. Delete the cloned operation.
|
|
b.eraseOp(clonedOp);
|
|
|
|
tiledResult.append(parallelOp->result_begin(), parallelOp->result_end());
|
|
// 4d. Compute the offsets and sizes needed to insert the result of the
|
|
// tiled value back into destination before yielding the destination.
|
|
SmallVector<OpFoldResult> outOffsets(offsets.size(), b.getIndexAttr(0));
|
|
resultOffsets.emplace_back(std::move(outOffsets));
|
|
|
|
SmallVector<OpFoldResult> outSizes;
|
|
for (size_t i = 0; i < offsets.size(); i++) {
|
|
outSizes.push_back(
|
|
tensor::getMixedSize(b, loc, parallelOp->getResult(0), i));
|
|
}
|
|
resultSizes.emplace_back(std::move(outSizes));
|
|
return success();
|
|
};
|
|
|
|
// 5. Generate the tiled implementation using the destination tensors.
|
|
SmallVector<Value> destinationTensors =
|
|
llvm::map_to_vector(identityTensor.value()->getResults(),
|
|
[](OpResult res) -> Value { return res; });
|
|
|
|
SmallVector<LoopLikeOpInterface> loops;
|
|
scf::SCFTilingOptions options;
|
|
options.setLoopType(scf::SCFTilingOptions::LoopType::ForOp);
|
|
if (failed(generateLoopNest(b, loc, options, iterationDomain, tileSizesVector,
|
|
destinationTensors, innerYieldTiledValuesFn,
|
|
loops)))
|
|
return b.notifyMatchFailure(op, "failed to tile for parallel reduction");
|
|
|
|
SmallVector<Value> replacements = llvm::map_to_vector(
|
|
loops.front()->getResults(), [](OpResult r) -> Value { return r; });
|
|
|
|
// 5. Apply the merge reduction to combine all the partial values.
|
|
b.setInsertionPointAfter(*loops.begin());
|
|
Operation *mergeOp = op.mergeReductions(b, loc, replacements, reductionDims);
|
|
b.replaceOp(op, mergeOp->getResults());
|
|
|
|
SCFReductionTilingResult results;
|
|
results.initialOp = *identityTensor;
|
|
results.loops = loops;
|
|
results.parallelTiledOp = parallelOp;
|
|
results.mergeOp = mergeOp;
|
|
return results;
|
|
}
|
|
|
|
//===----------------------------------------------------------------------===//
|
|
// tileConsumerAndFuseProducersUsingSCF implementation.
|
|
//===----------------------------------------------------------------------===//
|
|
|
|
/// Return the untiled producer whose slice is used in a tiled consumer. The
|
|
/// method traverses the tile loop nest (`loops`) if needed, and returns the
|
|
/// `iter_args` of the outer most that is encountered. Traversing the iter_args
|
|
/// indicates that this is a destination operand of the consumer. If there was
|
|
/// no loop traversal needed, the second value of the returned tuple is empty.
|
|
static std::tuple<OpResult, std::optional<OpOperand *>>
|
|
getUntiledProducerFromSliceSource(OpOperand *source,
|
|
ArrayRef<LoopLikeOpInterface> loops) {
|
|
std::optional<OpOperand *> destinationIterArg;
|
|
auto loopIt = loops.rbegin();
|
|
while (auto iterArg = dyn_cast<BlockArgument>(source->get())) {
|
|
auto loop = *loopIt;
|
|
if (iterArg.getOwner()->getParentOp() != loop)
|
|
break;
|
|
source = loop.getTiedLoopInit(iterArg);
|
|
loopIt++;
|
|
}
|
|
if (loopIt == loops.rend())
|
|
destinationIterArg = source;
|
|
return {dyn_cast<OpResult>(source->get()), destinationIterArg};
|
|
}
|
|
|
|
/// Implementation of fusing producer of a single slice by computing the
|
|
/// slice of the producer in-place.
|
|
std::optional<scf::SCFFuseProducerOfSliceResult>
|
|
mlir::scf::tileAndFuseProducerOfSlice(
|
|
RewriterBase &rewriter, tensor::ExtractSliceOp candidateSliceOp,
|
|
MutableArrayRef<LoopLikeOpInterface> loops) {
|
|
// 1. Get the producer of the source (potentially walking through
|
|
// `iter_args` of nested `scf.for`)
|
|
auto [fusableProducer, destinationInitArg] =
|
|
getUntiledProducerFromSliceSource(&candidateSliceOp.getSourceMutable(),
|
|
loops);
|
|
if (!fusableProducer)
|
|
return std::nullopt;
|
|
unsigned resultNumber = fusableProducer.getResultNumber();
|
|
|
|
OpBuilder::InsertionGuard g(rewriter);
|
|
rewriter.setInsertionPoint(candidateSliceOp);
|
|
|
|
// 2. Clone the fused producer
|
|
// 2a. Compute the destination operands to use for the cloned operation.
|
|
SmallVector<Value> origDestinationTensors, clonedOpDestinationTensors;
|
|
Operation *fusableProducerOp = fusableProducer.getOwner();
|
|
if (isa<DestinationStyleOpInterface>(fusableProducerOp) &&
|
|
failed(tensor::getOrCreateDestinations(
|
|
rewriter, fusableProducerOp->getLoc(), fusableProducerOp,
|
|
origDestinationTensors)))
|
|
return std::nullopt;
|
|
|
|
clonedOpDestinationTensors = origDestinationTensors;
|
|
if (destinationInitArg &&
|
|
isa<DestinationStyleOpInterface>(fusableProducerOp)) {
|
|
// 2b. If the producer is also destination style, then to maintain the
|
|
// destination passing style, update the destination of the producer to be
|
|
// the source of the slice.
|
|
clonedOpDestinationTensors[resultNumber] = candidateSliceOp.getSource();
|
|
}
|
|
// 2c. Clone the fused producer.
|
|
Operation *clonedProducerOp = cloneOpAndUpdateDestinationArgs(
|
|
rewriter, fusableProducerOp, clonedOpDestinationTensors);
|
|
// 2d. Update the source of the candidateSlice to be the cloned producer.
|
|
// Easier to just clone the slice with different source since replacements
|
|
// and DCE of cloned ops becomes easier
|
|
SmallVector<Value> candidateSliceOpOperands =
|
|
llvm::to_vector(candidateSliceOp->getOperands());
|
|
candidateSliceOpOperands[0] = clonedProducerOp->getResult(resultNumber);
|
|
tensor::ExtractSliceOp clonedCandidateSliceOp =
|
|
mlir::clone(rewriter, candidateSliceOp,
|
|
candidateSliceOp->getResultTypes(), candidateSliceOpOperands);
|
|
|
|
// 3. Generate the tiled implementation of the producer of the source
|
|
FailureOr<TilingResult> tileAndFuseResult =
|
|
tensor::replaceExtractSliceWithTiledProducer(
|
|
rewriter, clonedCandidateSliceOp,
|
|
clonedProducerOp->getResult(resultNumber));
|
|
if (failed(tileAndFuseResult))
|
|
return std::nullopt;
|
|
// Note: Do not delete the candidateSliceOp, since its passed in from the
|
|
// caller.
|
|
rewriter.replaceAllUsesWith(candidateSliceOp,
|
|
tileAndFuseResult->tiledValues[0]);
|
|
rewriter.eraseOp(clonedCandidateSliceOp);
|
|
rewriter.eraseOp(clonedProducerOp);
|
|
|
|
// 3. If the slice is for a destination operand, for example,
|
|
//
|
|
// ```mlir
|
|
// %0 = linalg.init
|
|
// %1 = linalg.fill .. outs(%0 : )
|
|
// %2 = scf.for .. iter_args(%arg0 = %1) {
|
|
// %3 = scf.for .. iter_args(%arg1 = %arg0) {
|
|
// %4 = tensor.extract_slice %arg1 [..]
|
|
// .. = linalg.matmul .. outs(%4 : )
|
|
// }
|
|
// }
|
|
// ```
|
|
//
|
|
// the IR is currently
|
|
//
|
|
// ```
|
|
// %0 = linalg.init
|
|
// %1 = linalg.fill
|
|
// %2 = scf.for .. iter_args(%arg0 = %1 /* incorrect value */ ) {
|
|
// %3 = scf.for .. iter_args(%arg1 = %arg0) {
|
|
// %4 = tensor.extract_slice %arg1[..]
|
|
// %5 = linalg.fill .. outs(%4 : )
|
|
// .. = linalg.matmul .. outs(%5 : )
|
|
// }
|
|
// }
|
|
// ```
|
|
//
|
|
// The untiled `linalg.fill` is still used as the `init_value` since it
|
|
// was originally a destination operand of the untiled `linalg.matmul`.
|
|
// When fusing an operand that is a destination operand, the iter_arg of
|
|
// the outer most loop should be changed to use the destination of the
|
|
// fused operation. With this the IR will be.
|
|
//
|
|
// ```
|
|
// %0 = linalg.init
|
|
// %1 = scf.for .. iter_args(%arg0 = %0 /* corrected value */ ) {
|
|
// %2 = scf.for .. iter_args(%arg1 = %arg0) {
|
|
// %3 = tensor.extract_slice %arg1[..]
|
|
// %4 = linalg.fill .. outs(%3 : )
|
|
// .. = linalg.matmul .. outs(%4 : )
|
|
// }
|
|
// }
|
|
// ```
|
|
if (destinationInitArg &&
|
|
isa<DestinationStyleOpInterface>(fusableProducerOp) && !loops.empty()) {
|
|
loops.front()
|
|
->getOpOperands()[destinationInitArg.value()->getOperandNumber()]
|
|
.set(origDestinationTensors[resultNumber]);
|
|
}
|
|
return scf::SCFFuseProducerOfSliceResult{fusableProducer,
|
|
tileAndFuseResult->tiledValues[0],
|
|
tileAndFuseResult->tiledOps};
|
|
}
|
|
|
|
/// Reconstruct the fused producer from within the tiled-and-fused code.
|
|
LogicalResult mlir::scf::yieldReplacementForFusedProducer(
|
|
RewriterBase &rewriter, tensor::ExtractSliceOp sliceOp,
|
|
scf::SCFFuseProducerOfSliceResult fusedProducerInfo,
|
|
MutableArrayRef<LoopLikeOpInterface> loops) {
|
|
if (loops.empty())
|
|
return success();
|
|
|
|
OpResult fusableProducer = fusedProducerInfo.origProducer;
|
|
Value tiledAndFusedProducer = fusedProducerInfo.tiledAndFusedProducer;
|
|
FailureOr<Value> initValue = tensor::getOrCreateDestination(
|
|
rewriter, fusableProducer.getOwner()->getLoc(), fusableProducer);
|
|
if (succeeded(initValue)) {
|
|
|
|
YieldTiledValuesFn newYieldValuesFn =
|
|
[&](RewriterBase &innerRewriter, Location loc, ValueRange /*ivs*/,
|
|
ValueRange newRegionIterArgs, SmallVector<Value> &tiledResult,
|
|
SmallVector<SmallVector<OpFoldResult>> &tiledOffset,
|
|
SmallVector<SmallVector<OpFoldResult>> &tiledSizes)
|
|
-> LogicalResult {
|
|
OpBuilder::InsertionGuard g(innerRewriter);
|
|
if (auto tiledDestStyleOp =
|
|
tiledAndFusedProducer
|
|
.getDefiningOp<DestinationStyleOpInterface>()) {
|
|
rewriter.setInsertionPoint(tiledDestStyleOp);
|
|
Value newRegionArg = newRegionIterArgs.back();
|
|
auto destSlice = rewriter.create<tensor::ExtractSliceOp>(
|
|
sliceOp.getLoc(), newRegionArg, sliceOp.getMixedOffsets(),
|
|
sliceOp.getMixedSizes(), sliceOp.getMixedStrides());
|
|
unsigned resultNumber = fusableProducer.getResultNumber();
|
|
rewriter.modifyOpInPlace(tiledDestStyleOp, [&]() {
|
|
tiledDestStyleOp.getDpsInitsMutable()[resultNumber].set(destSlice);
|
|
});
|
|
}
|
|
Block *block = rewriter.getInsertionPoint()->getBlock();
|
|
rewriter.setInsertionPoint(block->getTerminator());
|
|
tiledResult.push_back(fusedProducerInfo.tiledAndFusedProducer);
|
|
tiledOffset.emplace_back(sliceOp.getMixedOffsets());
|
|
tiledSizes.emplace_back(sliceOp.getMixedSizes());
|
|
return success();
|
|
};
|
|
|
|
return addInitOperandsToLoopNest(rewriter, loops,
|
|
SmallVector<Value>{initValue.value()},
|
|
newYieldValuesFn);
|
|
}
|
|
return success();
|
|
}
|
|
|
|
/// Implementation of tile consumer and fuse producer greedily.
|
|
FailureOr<scf::SCFTileAndFuseResult>
|
|
mlir::scf::tileConsumerAndFuseProducersUsingSCF(
|
|
RewriterBase &rewriter, TilingInterface consumer,
|
|
const scf::SCFTileAndFuseOptions &options) {
|
|
// This transformation is only valid for ops that return values (i.e. not
|
|
// valid to use with operations that have memref operands).
|
|
if (!consumer->getNumResults()) {
|
|
return rewriter.notifyMatchFailure(
|
|
consumer, "invalid pattern for op with no results");
|
|
}
|
|
|
|
// 1. First tile the consumer.
|
|
SetVector<Operation *> fusedProducers, tiledAndFusedOps;
|
|
llvm::SmallDenseMap<Value, size_t> origProducerToLoopResultNum;
|
|
|
|
FailureOr<scf::SCFTilingResult> tilingResult =
|
|
tileUsingSCF(rewriter, consumer, options.tilingOptions);
|
|
|
|
if (failed(tilingResult))
|
|
return rewriter.notifyMatchFailure(consumer, "failed to tile consumer");
|
|
for (auto *tiledOp : tilingResult->tiledOps)
|
|
tiledAndFusedOps.insert(tiledOp);
|
|
|
|
// If there are no loops generated, fusion is immaterial.
|
|
auto &loops = tilingResult->loops;
|
|
if (loops.empty()) {
|
|
DenseMap<Value, Value> replacements;
|
|
for (auto [origVal, replacement] :
|
|
llvm::zip_equal(consumer->getResults(), tilingResult->replacements)) {
|
|
replacements[origVal] = replacement;
|
|
}
|
|
return scf::SCFTileAndFuseResult{fusedProducers, tiledAndFusedOps, loops,
|
|
replacements};
|
|
}
|
|
|
|
// To keep track of replacements for now just record the map from the original
|
|
// untiled value to the result number of the for loop. Since the loop gets
|
|
// potentially replaced during fusion, keeping the value directly wont work.
|
|
DenseMap<Value, size_t> origValToResultNumber;
|
|
for (auto [index, result] : llvm::enumerate(consumer->getResults())) {
|
|
origValToResultNumber[result] = index;
|
|
}
|
|
|
|
// 2. Typically, the operands of the tiled operation are slices of the
|
|
// operands of the untiled operation. These are expressed in IR using
|
|
// `tensor.extract_slice` operations with source being the operands of the
|
|
// untiled operation. Create a worklist of these `tensor.extract_slice`
|
|
// operations. If the producers of the source of the `tensor.extract_slice`
|
|
// can be tiled such that the tiled value is generated in-place, that
|
|
// effectively tiles + fuses the operations.
|
|
auto addCandidateSlices = [](Operation *fusedOp,
|
|
std::deque<tensor::ExtractSliceOp> &candidates) {
|
|
for (Value operand : fusedOp->getOperands())
|
|
if (auto sliceOp = operand.getDefiningOp<tensor::ExtractSliceOp>())
|
|
candidates.push_back(sliceOp);
|
|
};
|
|
|
|
std::deque<tensor::ExtractSliceOp> candidates;
|
|
addCandidateSlices(tiledAndFusedOps.back(), candidates);
|
|
OpBuilder::InsertionGuard g(rewriter);
|
|
while (!candidates.empty()) {
|
|
// Traverse the slices in BFS fashion.
|
|
tensor::ExtractSliceOp candidateSliceOp = candidates.front();
|
|
candidates.pop_front();
|
|
|
|
// Find the original producer of the slice.
|
|
auto [fusableProducer, destinationInitArg] =
|
|
getUntiledProducerFromSliceSource(&candidateSliceOp.getSourceMutable(),
|
|
loops);
|
|
if (!fusableProducer)
|
|
continue;
|
|
|
|
auto [fuseSlice, yieldReplacement] = options.fusionControlFn(
|
|
candidateSliceOp, fusableProducer, destinationInitArg.has_value());
|
|
if (!fuseSlice)
|
|
continue;
|
|
|
|
// The operands of the fused producer might themselved be slices of
|
|
// values produced by operations that implement the `TilingInterface`.
|
|
// Add these operations to the worklist.
|
|
std::optional<scf::SCFFuseProducerOfSliceResult> fusedResult =
|
|
tileAndFuseProducerOfSlice(rewriter, candidateSliceOp, loops);
|
|
if (!fusedResult)
|
|
continue;
|
|
|
|
if (yieldReplacement) {
|
|
if (failed(yieldReplacementForFusedProducer(
|
|
rewriter, candidateSliceOp, fusedResult.value(), loops))) {
|
|
return rewriter.notifyMatchFailure(
|
|
fusableProducer.getOwner(), "failed to replacement value for this "
|
|
"oepration from within the tiled loop");
|
|
}
|
|
origValToResultNumber[fusableProducer] =
|
|
loops.front()->getNumResults() - 1;
|
|
}
|
|
|
|
if (Operation *tiledAndFusedOp =
|
|
fusedResult->tiledAndFusedProducer.getDefiningOp()) {
|
|
fusedProducers.insert(fusedResult->origProducer.getDefiningOp());
|
|
tiledAndFusedOps.insert(tiledAndFusedOp);
|
|
addCandidateSlices(tiledAndFusedOp, candidates);
|
|
}
|
|
}
|
|
|
|
DenseMap<Value, Value> replacements;
|
|
for (auto [origVal, resultNumber] : origValToResultNumber) {
|
|
replacements[origVal] = loops.front()->getResult(resultNumber);
|
|
}
|
|
|
|
return scf::SCFTileAndFuseResult{fusedProducers, tiledAndFusedOps, loops,
|
|
replacements};
|
|
}
|
|
|
|
//===----------------------------------------------------------------------===//
|
|
// lowerToLoopsUsingSCFForOp implementation.
|
|
//===----------------------------------------------------------------------===//
|
|
|
|
FailureOr<SmallVector<scf::ForOp>>
|
|
mlir::scf::lowerToLoopsUsingSCFForOp(RewriterBase &rewriter,
|
|
TilingInterface op) {
|
|
// TODO: Handle cases where the op has results if needed.
|
|
if (op->getNumResults() > 0) {
|
|
return rewriter.notifyMatchFailure(
|
|
op, "unable to lower to loops operations with return values");
|
|
}
|
|
|
|
SmallVector<Range> domain = op.getIterationDomain(rewriter);
|
|
SmallVector<Value> ivs;
|
|
SmallVector<scf::ForOp> loops;
|
|
Location loc = op.getLoc();
|
|
for (auto loopRange : domain) {
|
|
Value offsetVal =
|
|
getValueOrCreateConstantIndexOp(rewriter, loc, loopRange.offset);
|
|
Value sizeVal =
|
|
getValueOrCreateConstantIndexOp(rewriter, loc, loopRange.size);
|
|
Value strideVal =
|
|
getValueOrCreateConstantIndexOp(rewriter, loc, loopRange.stride);
|
|
auto loop = rewriter.create<scf::ForOp>(op.getLoc(), offsetVal, sizeVal,
|
|
strideVal, ValueRange{});
|
|
loops.push_back(loop);
|
|
ivs.push_back(loop.getInductionVar());
|
|
rewriter.setInsertionPoint(loop.getBody()->getTerminator());
|
|
}
|
|
if (failed(op.generateScalarImplementation(rewriter, op.getLoc(), ivs))) {
|
|
return failure();
|
|
}
|
|
return loops;
|
|
}
|