xref: /llvm-project/mlir/test/lib/Dialect/LLVM/TestLowerToLLVM.cpp (revision eb6c4197d5263ed2e086925b2b2f032a19442d2b)
1 //===- TestLowerToLLVM.cpp - Test lowering to LLVM as a sink 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 pass for testing the lowering to LLVM as a generally
10 // usable sink pass.
11 //
12 //===----------------------------------------------------------------------===//
13 
14 #include "mlir/Conversion/AffineToStandard/AffineToStandard.h"
15 #include "mlir/Conversion/ArithToLLVM/ArithToLLVM.h"
16 #include "mlir/Conversion/ControlFlowToLLVM/ControlFlowToLLVM.h"
17 #include "mlir/Conversion/FuncToLLVM/ConvertFuncToLLVMPass.h"
18 #include "mlir/Conversion/IndexToLLVM/IndexToLLVM.h"
19 #include "mlir/Conversion/MathToLLVM/MathToLLVM.h"
20 #include "mlir/Conversion/MemRefToLLVM/MemRefToLLVM.h"
21 #include "mlir/Conversion/ReconcileUnrealizedCasts/ReconcileUnrealizedCasts.h"
22 #include "mlir/Conversion/SCFToControlFlow/SCFToControlFlow.h"
23 #include "mlir/Conversion/VectorToLLVM/ConvertVectorToLLVMPass.h"
24 #include "mlir/Conversion/VectorToSCF/VectorToSCF.h"
25 #include "mlir/Dialect/Func/IR/FuncOps.h"
26 #include "mlir/Dialect/LLVMIR/LLVMDialect.h"
27 #include "mlir/Dialect/Linalg/Passes.h"
28 #include "mlir/Dialect/MemRef/Transforms/Passes.h"
29 #include "mlir/IR/DialectRegistry.h"
30 #include "mlir/Pass/Pass.h"
31 #include "mlir/Pass/PassManager.h"
32 #include "mlir/Pass/PassOptions.h"
33 #include "mlir/Transforms/Passes.h"
34 
35 using namespace mlir;
36 
37 namespace {
38 struct TestLowerToLLVMOptions
39     : public PassPipelineOptions<TestLowerToLLVMOptions> {
40   PassOptions::Option<bool> reassociateFPReductions{
41       *this, "reassociate-fp-reductions",
42       llvm::cl::desc("Allow reassociation og FP reductions"),
43       llvm::cl::init(false)};
44 };
45 
46 void buildTestLowerToLLVM(OpPassManager &pm,
47                           const TestLowerToLLVMOptions &options) {
48 
49   // TODO: it is feasible to scope lowering at arbitrary level and introduce
50   // unrealized casts, but there needs to be the final module-wise cleanup in
51   // the end. Keep module-level for now.
52 
53   // Blanket-convert any remaining high-level vector ops to loops if any remain.
54   pm.addNestedPass<func::FuncOp>(createConvertVectorToSCFPass());
55   // Blanket-convert any remaining linalg ops to loops if any remain.
56   pm.addNestedPass<func::FuncOp>(createConvertLinalgToLoopsPass());
57   // Blanket-convert any remaining affine ops if any remain.
58   pm.addPass(createLowerAffinePass());
59   // Convert SCF to CF (always needed).
60   pm.addPass(createConvertSCFToCFPass());
61   // Sprinkle some cleanups.
62   pm.addPass(createCanonicalizerPass());
63   pm.addPass(createCSEPass());
64   // Convert vector to LLVM (always needed).
65   pm.addPass(createConvertVectorToLLVMPass(
66       // TODO: add more options on a per-need basis.
67       ConvertVectorToLLVMPassOptions{options.reassociateFPReductions}));
68   // Convert Math to LLVM (always needed).
69   pm.addNestedPass<func::FuncOp>(createConvertMathToLLVMPass());
70   // Expand complicated MemRef operations before lowering them.
71   pm.addPass(memref::createExpandStridedMetadataPass());
72   // The expansion may create affine expressions. Get rid of them.
73   pm.addPass(createLowerAffinePass());
74   // Convert MemRef to LLVM (always needed).
75   pm.addPass(createFinalizeMemRefToLLVMConversionPass());
76   // Convert Func to LLVM (always needed).
77   pm.addPass(createConvertFuncToLLVMPass());
78   // Convert Arith to LLVM (always needed).
79   pm.addPass(createArithToLLVMConversionPass());
80   // Convert CF to LLVM (always needed).
81   pm.addPass(createConvertControlFlowToLLVMPass());
82   // Convert Index to LLVM (always needed).
83   pm.addPass(createConvertIndexToLLVMPass());
84   // Convert remaining unrealized_casts (always needed).
85   pm.addPass(createReconcileUnrealizedCastsPass());
86 }
87 } // namespace
88 
89 namespace mlir {
90 namespace test {
91 void registerTestLowerToLLVM() {
92   PassPipelineRegistration<TestLowerToLLVMOptions>(
93       "test-lower-to-llvm",
94       "An example of pipeline to lower the main dialects (arith, linalg, "
95       "memref, scf, vector) down to LLVM.",
96       buildTestLowerToLLVM);
97 }
98 } // namespace test
99 } // namespace mlir
100