1 //===- TestAffineDataCopy.cpp - Test affine data copy utility -------------===//
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 pass to test affine data copy utility functions and
10 // options.
11 //
12 //===----------------------------------------------------------------------===//
13 
14 #include "mlir/Dialect/Affine/Analysis/Utils.h"
15 #include "mlir/Dialect/Affine/IR/AffineOps.h"
16 #include "mlir/Dialect/Affine/LoopUtils.h"
17 #include "mlir/Dialect/Func/IR/FuncOps.h"
18 #include "mlir/Dialect/MemRef/IR/MemRef.h"
19 #include "mlir/Pass/Pass.h"
20 #include "mlir/Transforms/GreedyPatternRewriteDriver.h"
21 #include "mlir/Transforms/Passes.h"
22 
23 #define PASS_NAME "test-affine-data-copy"
24 
25 using namespace mlir;
26 
27 namespace {
28 
29 struct TestAffineDataCopy
30     : public PassWrapper<TestAffineDataCopy, OperationPass<func::FuncOp>> {
31   MLIR_DEFINE_EXPLICIT_INTERNAL_INLINE_TYPE_ID(TestAffineDataCopy)
32 
33   StringRef getArgument() const final { return PASS_NAME; }
34   StringRef getDescription() const final {
35     return "Tests affine data copy utility functions.";
36   }
37   TestAffineDataCopy() = default;
38   TestAffineDataCopy(const TestAffineDataCopy &pass) : PassWrapper(pass){};
39 
40   void getDependentDialects(DialectRegistry &registry) const override {
41     registry.insert<memref::MemRefDialect>();
42   }
43   void runOnOperation() override;
44 
45 private:
46   Option<bool> clMemRefFilter{
47       *this, "memref-filter",
48       llvm::cl::desc(
49           "Enable memref filter testing in affine data copy optimization"),
50       llvm::cl::init(false)};
51   Option<bool> clTestGenerateCopyForMemRegion{
52       *this, "for-memref-region",
53       llvm::cl::desc("Test copy generation for a single memref region"),
54       llvm::cl::init(false)};
55 };
56 
57 } // namespace
58 
59 void TestAffineDataCopy::runOnOperation() {
60   // Gather all AffineForOps by loop depth.
61   std::vector<SmallVector<AffineForOp, 2>> depthToLoops;
62   gatherLoops(getOperation(), depthToLoops);
63   assert(!depthToLoops.empty() && "Loop nest not found");
64 
65   // Only support tests with a single loop nest and a single innermost loop
66   // for now.
67   unsigned innermostLoopIdx = depthToLoops.size() - 1;
68   if (depthToLoops[0].size() != 1 || depthToLoops[innermostLoopIdx].size() != 1)
69     return;
70 
71   auto loopNest = depthToLoops[0][0];
72   auto innermostLoop = depthToLoops[innermostLoopIdx][0];
73   AffineLoadOp load;
74   if (clMemRefFilter || clTestGenerateCopyForMemRegion) {
75     // Gather MemRef filter. For simplicity, we use the first loaded memref
76     // found in the innermost loop.
77     for (auto &op : *innermostLoop.getBody()) {
78       if (auto ld = dyn_cast<AffineLoadOp>(op)) {
79         load = ld;
80         break;
81       }
82     }
83   }
84   if (!load)
85     return;
86 
87   AffineCopyOptions copyOptions = {/*generateDma=*/false,
88                                    /*slowMemorySpace=*/0,
89                                    /*fastMemorySpace=*/0,
90                                    /*tagMemorySpace=*/0,
91                                    /*fastMemCapacityBytes=*/32 * 1024 * 1024UL};
92   DenseSet<Operation *> copyNests;
93   if (clMemRefFilter) {
94     if (failed(affineDataCopyGenerate(loopNest, copyOptions, load.getMemRef(),
95                                       copyNests)))
96       return;
97   } else if (clTestGenerateCopyForMemRegion) {
98     CopyGenerateResult result;
99     MemRefRegion region(loopNest.getLoc());
100     if (failed(region.compute(load, /*loopDepth=*/0)))
101       return;
102     if (failed(generateCopyForMemRegion(region, loopNest, copyOptions, result)))
103       return;
104   }
105 
106   // Promote any single iteration loops in the copy nests and simplify
107   // load/stores.
108   SmallVector<Operation *, 4> copyOps;
109   for (Operation *nest : copyNests) {
110     // With a post order walk, the erasure of loops does not affect
111     // continuation of the walk or the collection of load/store ops.
112     nest->walk([&](Operation *op) {
113       if (auto forOp = dyn_cast<AffineForOp>(op))
114         (void)promoteIfSingleIteration(forOp);
115       else if (auto loadOp = dyn_cast<AffineLoadOp>(op))
116         copyOps.push_back(loadOp);
117       else if (auto storeOp = dyn_cast<AffineStoreOp>(op))
118         copyOps.push_back(storeOp);
119     });
120   }
121 
122   // Promoting single iteration loops could lead to simplification of
123   // generated load's/store's, and the latter could anyway also be
124   // canonicalized.
125   RewritePatternSet patterns(&getContext());
126   for (Operation *op : copyOps) {
127     patterns.clear();
128     if (isa<AffineLoadOp>(op)) {
129       AffineLoadOp::getCanonicalizationPatterns(patterns, &getContext());
130     } else {
131       assert(isa<AffineStoreOp>(op) && "expected affine store op");
132       AffineStoreOp::getCanonicalizationPatterns(patterns, &getContext());
133     }
134   }
135   (void)applyOpPatternsAndFold(copyOps, std::move(patterns), /*strict=*/true);
136 }
137 
138 namespace mlir {
139 void registerTestAffineDataCopyPass() {
140   PassRegistration<TestAffineDataCopy>();
141 }
142 } // namespace mlir
143