1 //= TestAffineLoopParametricTiling.cpp -- Parametric Affine loop tiling pass =//
2 //
3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4 // See https://llvm.org/LICENSE.txt for license information.
5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6 //
7 //===----------------------------------------------------------------------===//
8 //
9 // This file implements a test pass to test parametric tiling of perfectly
10 // nested affine for loops.
11 //
12 //===----------------------------------------------------------------------===//
13
14 #include "mlir/Dialect/Affine/IR/AffineOps.h"
15 #include "mlir/Dialect/Affine/LoopUtils.h"
16 #include "mlir/Dialect/Affine/Passes.h"
17 #include "mlir/Dialect/Func/IR/FuncOps.h"
18
19 using namespace mlir;
20
21 #define DEBUG_TYPE "test-affine-parametric-tile"
22
23 namespace {
24 struct TestAffineLoopParametricTiling
25 : public PassWrapper<TestAffineLoopParametricTiling,
26 OperationPass<func::FuncOp>> {
MLIR_DEFINE_EXPLICIT_INTERNAL_INLINE_TYPE_ID__anondad0e7f70111::TestAffineLoopParametricTiling27 MLIR_DEFINE_EXPLICIT_INTERNAL_INLINE_TYPE_ID(TestAffineLoopParametricTiling)
28
29 StringRef getArgument() const final { return "test-affine-parametric-tile"; }
getDescription__anondad0e7f70111::TestAffineLoopParametricTiling30 StringRef getDescription() const final {
31 return "Tile affine loops using SSA values as tile sizes";
32 }
33 void runOnOperation() override;
34 };
35 } // namespace
36
37 /// Checks if the function enclosing the loop nest has any arguments passed to
38 /// it, which can be used as tiling parameters. Assumes that atleast 'n'
39 /// arguments are passed, where 'n' is the number of loops in the loop nest.
checkIfTilingParametersExist(ArrayRef<AffineForOp> band)40 static void checkIfTilingParametersExist(ArrayRef<AffineForOp> band) {
41 assert(!band.empty() && "no loops in input band");
42 AffineForOp topLoop = band[0];
43
44 if (func::FuncOp funcOp = dyn_cast<func::FuncOp>(topLoop->getParentOp()))
45 assert(funcOp.getNumArguments() >= band.size() && "Too few tile sizes");
46 }
47
48 /// Captures tiling parameters, which are expected to be passed as arguments
49 /// to the function enclosing the loop nest. Also checks if the required
50 /// parameters are of index type. This approach is temporary for testing
51 /// purposes.
getTilingParameters(ArrayRef<AffineForOp> band,SmallVectorImpl<Value> & tilingParameters)52 static void getTilingParameters(ArrayRef<AffineForOp> band,
53 SmallVectorImpl<Value> &tilingParameters) {
54 AffineForOp topLoop = band[0];
55 Region *funcOpRegion = topLoop->getParentRegion();
56 unsigned nestDepth = band.size();
57
58 for (BlockArgument blockArgument :
59 funcOpRegion->getArguments().take_front(nestDepth)) {
60 if (blockArgument.getArgNumber() < nestDepth) {
61 assert(blockArgument.getType().isIndex() &&
62 "expected tiling parameters to be of index type.");
63 tilingParameters.push_back(blockArgument);
64 }
65 }
66 }
67
runOnOperation()68 void TestAffineLoopParametricTiling::runOnOperation() {
69 // Bands of loops to tile.
70 std::vector<SmallVector<AffineForOp, 6>> bands;
71 getTileableBands(getOperation(), &bands);
72
73 // Tile each band.
74 for (MutableArrayRef<AffineForOp> band : bands) {
75 // Capture the tiling parameters from the arguments to the function
76 // enclosing this loop nest.
77 SmallVector<AffineForOp, 6> tiledNest;
78 SmallVector<Value, 6> tilingParameters;
79 // Check if tiling parameters are present.
80 checkIfTilingParametersExist(band);
81
82 // Get function arguments as tiling parameters.
83 getTilingParameters(band, tilingParameters);
84
85 (void)tilePerfectlyNestedParametric(band, tilingParameters, &tiledNest);
86 }
87 }
88
89 namespace mlir {
90 namespace test {
registerTestAffineLoopParametricTilingPass()91 void registerTestAffineLoopParametricTilingPass() {
92 PassRegistration<TestAffineLoopParametricTiling>();
93 }
94 } // namespace test
95 } // namespace mlir
96