7ee34550f5
The current approach for handling `iter_args` was to replace all uses of the value that is used as `init` value with the corresponding region block argument within the `scf.for`. This is not always correct. Instead a more deliberate approach needs to be taken to handle these. If the slice being fused represents a slice of the destination operand of the untiled op, then - Make the destination of the fused producer the `init` value of the loop nest - For the tiled and fused producer op created, replace the slice of the destination operand with a slice of the corresponding region iter arg of the innermost loop of the generated loop nest Differential Revision: https://reviews.llvm.org/D134411
616 lines
24 KiB
C++
616 lines
24 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/Arithmetic/IR/Arithmetic.h"
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#include "mlir/Dialect/Arithmetic/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/IR/Matchers.h"
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#include "mlir/IR/PatternMatch.h"
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#include "mlir/Interfaces/TilingInterface.h"
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#include "llvm/Support/Debug.h"
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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<int64_t> ts) {
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assert(!tileSizeComputationFunction && "tile sizes already set");
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SmallVector<int64_t> tileSizes(ts.begin(), ts.end());
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tileSizeComputationFunction = [tileSizes](OpBuilder &b, Operation *op) {
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OpBuilder::InsertionGuard guard(b);
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b.setInsertionPointToStart(
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&op->getParentOfType<func::FuncOp>().getBody().front());
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return llvm::to_vector<4>(map_range(tileSizes, [&](int64_t s) {
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Value v = b.create<arith::ConstantIndexOp>(op->getLoc(), s);
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return v;
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}));
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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<unsigned>
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fillInterchangeVector(ArrayRef<unsigned> interchangeVector,
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size_t iterationDomainSize) {
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SmallVector<unsigned> filledVector = llvm::to_vector(interchangeVector);
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if (filledVector.size() < iterationDomainSize) {
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auto range = llvm::seq<unsigned>(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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/// Helper method to apply permutation to a vector
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template <typename T>
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static SmallVector<T> applyPermutationToVector(const SmallVector<T> &vector,
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ArrayRef<unsigned> interchange) {
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assert(interchange.size() == vector.size());
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return llvm::to_vector(
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llvm::map_range(interchange, [&](unsigned val) { return vector[val]; }));
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}
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/// Helper method to apply to invert a permutation.
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static SmallVector<unsigned>
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invertPermutationVector(ArrayRef<unsigned> interchange) {
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SmallVector<unsigned> inversion(interchange.size());
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for (const auto &pos : llvm::enumerate(interchange)) {
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inversion[pos.value()] = pos.index();
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}
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return inversion;
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}
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/// Method to check if an interchange vector is a permutation.
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static bool isPermutation(ArrayRef<unsigned> interchange) {
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llvm::SmallDenseSet<unsigned, 4> seenVals;
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for (auto val : interchange) {
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if (seenVals.count(val))
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return false;
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seenVals.insert(val);
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}
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return seenVals.size() == interchange.size();
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}
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//===----------------------------------------------------------------------===//
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// TileUsingSCFForOp pattern 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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Optional<int64_t> offsetAsInt = getConstantIntValue(loopRange.offset);
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if (!offsetAsInt)
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return false;
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Optional<int64_t> sizeAsInt = getConstantIntValue(loopRange.size);
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if (!sizeAsInt)
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return false;
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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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/// Generate an empty loop nest that represents the tiled loop nest shell.
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/// - `loopRanges` specifies the lb, ub and step of the untiled iteration space.
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/// - `tileSizeVals` is the tile sizes to use. Zero represent untiled loops.
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/// - In `offsets` and `sizes` return the multi-dimensional offset and size of
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/// the
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/// tile processed within the inner most loop.
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static SmallVector<scf::ForOp>
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generateTileLoopNest(OpBuilder &builder, Location loc,
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ArrayRef<Range> loopRanges, ArrayRef<Value> tileSizeVals,
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SmallVector<OpFoldResult> &offsets,
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SmallVector<OpFoldResult> &sizes) {
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assert(!loopRanges.empty() && "expected at least one loop range");
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assert(loopRanges.size() == tileSizeVals.size() &&
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"expected as many tile sizes as loop ranges");
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OpBuilder::InsertionGuard guard(builder);
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SmallVector<scf::ForOp> loops;
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offsets.resize(loopRanges.size());
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sizes.resize(loopRanges.size());
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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
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// of the tiled loop.
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AffineExpr s0, s1, d0;
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bindDims(builder.getContext(), d0);
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bindSymbols(builder.getContext(), s0, s1);
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AffineMap minMap = AffineMap::get(1, 2, {s0, s1 - d0}, builder.getContext());
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for (auto loopRange : llvm::enumerate(loopRanges)) {
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Value offset =
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getValueOrCreateConstantIndexOp(builder, loc, loopRange.value().offset);
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Value size =
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getValueOrCreateConstantIndexOp(builder, loc, loopRange.value().size);
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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 (matchPattern(tileSizeVals[loopRange.index()], m_Zero())) {
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offsets[loopRange.index()] = offset;
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sizes[loopRange.index()] = size;
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continue;
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}
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auto loop = builder.create<scf::ForOp>(
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loc, offset, size, tileSizeVals[loopRange.index()], ValueRange{},
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[&](OpBuilder &bodyBuilder, Location bodyLoc, Value iv,
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ValueRange /*iterArgs*/) {
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bool canAvoidMap = tileDividesIterationDomain(
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Range{loopRange.value().offset, loopRange.value().size,
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tileSizeVals[loopRange.index()]});
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Value boundedTileSize =
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(canAvoidMap)
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? tileSizeVals[loopRange.index()]
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: builder.create<AffineMinOp>(
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bodyLoc, minMap,
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ValueRange{iv, tileSizeVals[loopRange.index()], size});
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sizes[loopRange.index()] = boundedTileSize;
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builder.create<scf::YieldOp>(loc);
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});
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offsets[loopRange.index()] = loop.getInductionVar();
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loops.push_back(loop);
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builder.setInsertionPoint(loop.getBody()->getTerminator());
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}
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return loops;
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}
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/// If the tiled operation is in destination passing style, update the
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/// slice of the destination used (which refers to the untiled destination)
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/// to use the corresponding region argument of the innermost loop.
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///
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/// ```mlir
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/// %0 =
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/// scf.for %iv0 = ... iter_args(%arg = %0) {
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/// %1 = tensor.extract_slice %0
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/// %2 = tiled_op
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/// %3 = tensor.insert_slice %2 into %arg
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/// scf.yield %3
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/// }
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/// ```
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///
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/// is transformed to
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///
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/// ```mlir
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/// scf.for %iv0 = ... iter_args(%arg = %0) {
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/// %1 = tensor.extract_slice %arg
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/// %2 = tiled_op
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/// %3 = tensor.insert_slice %2 into %arg
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/// scf.yield %3
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/// }
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/// ```
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/// TODO: This can be made much cleaner when `DestinationStyleOp` interface is
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/// available generally.
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static void
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updateDestinationOperandsForTiledOp(OpBuilder &builder,
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ValueRange tiledOpDestinationValues,
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ValueRange bbArgsList) {
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for (auto destValue : llvm::enumerate(tiledOpDestinationValues)) {
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auto sliceOp = destValue.value().getDefiningOp<tensor::ExtractSliceOp>();
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if (!sliceOp)
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continue;
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sliceOp.setOperand(0, bbArgsList[destValue.index()]);
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}
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}
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scf::TileUsingSCFForOp::TileUsingSCFForOp(MLIRContext *context,
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scf::SCFTilingOptions options,
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PatternBenefit benefit)
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: OpInterfaceRewritePattern<TilingInterface>(context, benefit),
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options(std::move(options)) {}
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scf::TileUsingSCFForOp::TileUsingSCFForOp(StringRef opName,
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MLIRContext *context,
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scf::SCFTilingOptions options,
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PatternBenefit benefit)
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: OpInterfaceRewritePattern<TilingInterface>(context, benefit),
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options(std::move(options)) {}
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FailureOr<scf::SCFTilingResult>
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scf::TileUsingSCFForOp::returningMatchAndRewrite(
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TilingInterface op, PatternRewriter &rewriter) const {
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OpBuilder::InsertionGuard guard(rewriter);
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rewriter.setInsertionPointAfter(op);
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if (!options.tileSizeComputationFunction) {
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return rewriter.notifyMatchFailure(
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op, "missing tile size computation function");
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}
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// 1. Get the range of the loops that are represented by the operation.
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SmallVector<Range> iterationDomain = op.getIterationDomain(rewriter);
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size_t numLoops = iterationDomain.size();
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if (numLoops == 0) {
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return rewriter.notifyMatchFailure(
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op, "unable to tile op with no iteration domain");
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}
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// 2. Materialize the tile sizes. Enforce the convention that "tiling by zero"
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// skips tiling a particular dimension. This convention is significantly
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// simpler to handle instead of adjusting affine maps to account for missing
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// dimensions.
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SmallVector<Value> tileSizeVector =
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options.tileSizeComputationFunction(rewriter, op);
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if (tileSizeVector.size() < iterationDomain.size()) {
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auto zero = rewriter.create<arith::ConstantIndexOp>(op.getLoc(), 0);
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tileSizeVector.append(numLoops - tileSizeVector.size(), zero);
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}
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scf::SCFTilingResult tilingResult;
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SmallVector<OpFoldResult> offsets, sizes;
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{
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// If there is an interchange specified, permute the iteration domain and
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// the tile sizes.
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SmallVector<unsigned> interchangeVector;
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if (!options.interchangeVector.empty()) {
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interchangeVector = fillInterchangeVector(options.interchangeVector,
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iterationDomain.size());
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}
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if (!interchangeVector.empty()) {
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if (!isPermutation(interchangeVector)) {
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return rewriter.notifyMatchFailure(
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op, "invalid intechange vector, not a permutation of the entire "
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"iteration space");
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}
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iterationDomain =
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applyPermutationToVector(iterationDomain, interchangeVector);
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tileSizeVector =
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applyPermutationToVector(tileSizeVector, interchangeVector);
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}
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// 3. Materialize an empty loop nest that iterates over the tiles. These
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// loops for now do not return any values even if the original operation has
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// results.
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tilingResult.loops = generateTileLoopNest(
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rewriter, op.getLoc(), iterationDomain, tileSizeVector, offsets, sizes);
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if (!interchangeVector.empty()) {
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auto inversePermutation = invertPermutationVector(interchangeVector);
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offsets = applyPermutationToVector(offsets, inversePermutation);
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sizes = applyPermutationToVector(sizes, inversePermutation);
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}
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LLVM_DEBUG({
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if (!tilingResult.loops.empty()) {
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llvm::errs() << "LoopNest shell :\n";
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tilingResult.loops.front().dump();
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llvm::errs() << "\n";
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}
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});
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// 4. Generate the tiled implementation within the inner most loop.
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if (!tilingResult.loops.empty())
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rewriter.setInsertionPoint(
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tilingResult.loops.back().getBody()->getTerminator());
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SmallVector<Operation *> tiledImplementation =
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op.getTiledImplementation(rewriter, offsets, sizes);
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if (tiledImplementation.size() != 1) {
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return rewriter.notifyMatchFailure(
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op, "expected tiled implementation to return a single op");
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}
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tilingResult.tiledOp = tiledImplementation[0];
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LLVM_DEBUG({
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if (!tilingResult.loops.empty()) {
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llvm::errs() << "After tiled implementation :\n";
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tilingResult.loops.front().dump();
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llvm::errs() << "\n";
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}
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});
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}
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if (op->getNumResults() == 0) {
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rewriter.eraseOp(op);
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return tilingResult;
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}
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// 5. If the original operations has results, modify the loop nest to yield
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// the replacement values.
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if (tilingResult.loops.empty()) {
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// 5a. If there were no loops, the tiled implementation results are the
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// replacements.
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rewriter.replaceOp(op, tilingResult.tiledOp->getResults());
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return tilingResult;
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}
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// 6. Yield the results of the tiled operation from the loop nest as
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// replacements for the original untiled ops.
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if (tilingResult.tiledOp->getNumResults() != op->getNumResults()) {
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return rewriter.notifyMatchFailure(
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tilingResult.tiledOp,
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"expected tiled op to have as many results as the untiled operation");
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}
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// `scf.for` with tensor semantics requires the loop nest to yield the
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// replacement values using destructive updates. Use the `TilingInterface`
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// to get the position of the result tiles and use that to generate the
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// destructive update pattern, i.e.,
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//
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// ```mlir
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// scf.for %iv0 = ... {
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// %0 = tiled_op
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// }
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// ```
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//
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// is transformed to
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//
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// ```mlir
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// %result = scf.for %iv0 = ... iter_args(%arg = %init) -> .. {
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// %0 = tiled_op
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// %1 = tensor.insert_slice %0 into %arg[..] [..] [..]
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// scf.yield %1
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// }
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// ```
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NewYieldValueFn yieldValueFn =
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[&](OpBuilder &b, Location loc,
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ArrayRef<BlockArgument> newBBArgs) -> SmallVector<Value> {
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SmallVector<Value> yieldedValues;
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Attribute one = b.getIndexAttr(1);
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for (auto resultNum : llvm::seq<unsigned>(0, op->getNumResults())) {
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SmallVector<OpFoldResult> resultTileOffsets, resultTileSizes;
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if (failed(op.getResultTilePosition(b, resultNum, offsets, sizes,
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resultTileOffsets,
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resultTileSizes))) {
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op.emitOpError("unable to get position of result ")
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<< resultNum << " of the tiled implementation";
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return {};
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}
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SmallVector<OpFoldResult> resultTileStrides(resultTileOffsets.size(),
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one);
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Value yieldedValue = b.create<tensor::InsertSliceOp>(
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op->getLoc(), tilingResult.tiledOp->getResult(resultNum),
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newBBArgs[resultNum], resultTileOffsets, resultTileSizes,
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resultTileStrides);
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yieldedValues.push_back(yieldedValue);
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}
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return yieldedValues;
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};
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SmallVector<scf::ForOp> newLoops = replaceLoopNestWithNewYields(
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rewriter, tilingResult.loops, op.getDestinationOperands(rewriter),
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yieldValueFn, /*replaceIterOperandsUsesInLoops =*/false);
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for (const auto &loop : llvm::enumerate(tilingResult.loops)) {
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rewriter.eraseOp(loop.value());
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tilingResult.loops[loop.index()] = newLoops[loop.index()];
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}
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rewriter.replaceOp(op, tilingResult.loops.front().getResults());
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return tilingResult;
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}
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//===----------------------------------------------------------------------===//
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// TileConsumerAndFuseProducersUsingSCFForOp pattern implementation.
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//===----------------------------------------------------------------------===//
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scf::TileConsumerAndFuseProducersUsingSCFForOp::
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TileConsumerAndFuseProducersUsingSCFForOp(MLIRContext *context,
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scf::SCFTilingOptions options,
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PatternBenefit benefit)
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: OpInterfaceRewritePattern<TilingInterface>(context, benefit),
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tilingPattern(context, std::move(options)) {}
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scf::TileConsumerAndFuseProducersUsingSCFForOp::
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TileConsumerAndFuseProducersUsingSCFForOp(StringRef opName,
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MLIRContext *context,
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scf::SCFTilingOptions options,
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PatternBenefit benefit)
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: OpInterfaceRewritePattern<TilingInterface>(context, benefit),
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tilingPattern(context, std::move(options)) {}
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/// Return the untiled producer whose slice is used in a tiled consumer. The
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/// method traverses the tile loop nest (`loops`) if needed, and returns the
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/// `iter_args` of the outer most that is encountered. Traversing the iter_args
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/// indicates that this is a destination operand of the consumer. If there was
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/// no loop traversal needed, the second value of the returned tuple is empty.
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static std::tuple<OpResult, Optional<OpOperand *>>
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getUntiledProducerFromSliceSource(OpOperand *source,
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ArrayRef<scf::ForOp> loops) {
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Optional<OpOperand *> destinationIterArg;
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auto loopIt = loops.rbegin();
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while (auto iterArg = source->get().dyn_cast<BlockArgument>()) {
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scf::ForOp loop = *loopIt;
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if (iterArg.getOwner()->getParentOp() != loop)
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break;
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source = &loop.getOpOperandForRegionIterArg(iterArg);
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loopIt++;
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}
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if (loopIt == loops.rend())
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destinationIterArg = source;
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return {source->get().dyn_cast<OpResult>(), destinationIterArg};
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}
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FailureOr<scf::SCFTileAndFuseResult>
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scf::TileConsumerAndFuseProducersUsingSCFForOp::returningMatchAndRewrite(
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TilingInterface op, PatternRewriter &rewriter) const {
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// This transformation is only valid for ops that return values (i.e. not
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// valid to use with operations that have memref operands).
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if (!op->getNumResults()) {
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return rewriter.notifyMatchFailure(
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op, "invalid pattern for op with no results");
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}
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// 1. First tile the consumer.
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SCFTileAndFuseResult tileAndFuseResult;
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{
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FailureOr<SCFTilingResult> tilingResult =
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tilingPattern.returningMatchAndRewrite(op, rewriter);
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if (failed(tilingResult)) {
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return failure();
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}
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tileAndFuseResult.tiledAndFusedOps.push_back(tilingResult->tiledOp);
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tileAndFuseResult.loops = std::move(tilingResult->loops);
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}
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// 2. Typically, the operands of the tiled operation are slices of the
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|
// 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,
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|
std::deque<tensor::ExtractSliceOp> &candidates) {
|
|
for (Value operand : fusedOp->getOperands())
|
|
if (auto sliceOp = operand.getDefiningOp<tensor::ExtractSliceOp>())
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|
candidates.push_back(sliceOp);
|
|
};
|
|
|
|
std::deque<tensor::ExtractSliceOp> candidates;
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|
addCandidateSlices(tileAndFuseResult.tiledAndFusedOps.back(), candidates);
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|
OpBuilder::InsertionGuard g(rewriter);
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|
while (!candidates.empty()) {
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|
// 2a. Traverse the slices in BFS fashion.
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|
tensor::ExtractSliceOp candidateSliceOp = candidates.front();
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|
candidates.pop_front();
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|
|
|
// 2b. Get the producer of the source (potentially walking through
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|
// `iter_args` of nested `scf.for`)
|
|
auto [fusableProducer, destinationIterArg] =
|
|
getUntiledProducerFromSliceSource(&candidateSliceOp->getOpOperand(0),
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|
tileAndFuseResult.loops);
|
|
if (!fusableProducer)
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|
continue;
|
|
|
|
// 2c. Generate the tiled implementation of the producer of the source
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|
rewriter.setInsertionPoint(candidateSliceOp);
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|
FailureOr<Value> fusedProducerValue =
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|
tensor::replaceExtractSliceWithTiledProducer(rewriter, candidateSliceOp,
|
|
fusableProducer);
|
|
if (failed(fusedProducerValue))
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|
continue;
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|
rewriter.replaceOp(candidateSliceOp, fusedProducerValue.value());
|
|
|
|
// 2d. 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.
|
|
Operation *fusedProducer = fusedProducerValue->getDefiningOp();
|
|
tileAndFuseResult.tiledAndFusedOps.push_back(fusedProducer);
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|
addCandidateSlices(fusedProducer, candidates);
|
|
|
|
// 2e. 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 %0 /*incorrect value */ [..]
|
|
// %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.
|
|
// - Update the iter_arg of the outer most loop to use the destination
|
|
// of the untiled producer.
|
|
// - Update the destination of the slice of the tiled producer generated
|
|
// to use the same basic block argument as the slice that was used to
|
|
// generate inplace the tiled implementation of the producer.
|
|
// 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 /* corrected value */ [..]
|
|
// %4 = linalg.fill .. outs(%3 : )
|
|
// .. = linalg.matmul .. outs(%4 : )
|
|
// }
|
|
// }
|
|
// ```
|
|
// TODO: This can be modeled better if the `DestinationStyleOpInterface`.
|
|
// Update to use that when it does become available.
|
|
scf::ForOp outerMostLoop = tileAndFuseResult.loops.front();
|
|
Optional<unsigned> iterArgNumber;
|
|
if (destinationIterArg) {
|
|
iterArgNumber = outerMostLoop.getIterArgNumberForOpOperand(
|
|
*destinationIterArg.value());
|
|
}
|
|
if (iterArgNumber) {
|
|
unsigned resultNumber = fusableProducer.getResultNumber();
|
|
if (auto producerOp =
|
|
dyn_cast<TilingInterface>(fusableProducer.getOwner())) {
|
|
SmallVector<Value> destination =
|
|
producerOp.getDestinationOperands(rewriter);
|
|
outerMostLoop.setIterArg(iterArgNumber.value(),
|
|
destination[resultNumber]);
|
|
}
|
|
if (auto tiledAndFusedInterfaceOp =
|
|
fusedProducerValue.value().getDefiningOp<TilingInterface>()) {
|
|
scf::ForOp innerMostLoop = tileAndFuseResult.loops.back();
|
|
SmallVector<Value> destination =
|
|
tiledAndFusedInterfaceOp.getDestinationOperands(rewriter);
|
|
updateDestinationOperandsForTiledOp(
|
|
rewriter, destination[resultNumber],
|
|
innerMostLoop.getRegionIterArgs()[iterArgNumber.value()]);
|
|
}
|
|
}
|
|
}
|
|
return tileAndFuseResult;
|
|
}
|
|
|
|
//===----------------------------------------------------------------------===//
|
|
// LowerToLoopsUsingSCFForOp
|
|
//===----------------------------------------------------------------------===//
|
|
|
|
FailureOr<SmallVector<scf::ForOp>>
|
|
scf::LowerToLoopsUsingSCFForOp::returningMatchAndRewrite(
|
|
TilingInterface op, PatternRewriter &rewriter) const {
|
|
SmallVector<Range> domain = op.getIterationDomain(rewriter);
|
|
|
|
// 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<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();
|
|
}
|
|
rewriter.eraseOp(op);
|
|
return loops;
|
|
}
|