1//===- FuncToEmitC.cpp - Func to EmitC Patterns -----------------*- C++ -*-===//
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 patterns to convert the Func dialect to the EmitC
10// dialect.
11//
12//===----------------------------------------------------------------------===//
13
14#include "mlir/Conversion/FuncToEmitC/FuncToEmitC.h"
15
16#include "mlir/Conversion/ConvertToEmitC/ToEmitCInterface.h"
17#include "mlir/Dialect/EmitC/IR/EmitC.h"
18#include "mlir/Dialect/Func/IR/FuncOps.h"
19#include "mlir/Transforms/DialectConversion.h"
20
21using namespace mlir;
22
23namespace {
24
25/// Implement the interface to convert Func to EmitC.
26struct FuncToEmitCDialectInterface : public ConvertToEmitCPatternInterface {
27 using ConvertToEmitCPatternInterface::ConvertToEmitCPatternInterface;
28
29 /// Hook for derived dialect interface to provide conversion patterns
30 /// and mark dialect legal for the conversion target.
31 void populateConvertToEmitCConversionPatterns(
32 ConversionTarget &target, TypeConverter &typeConverter,
33 RewritePatternSet &patterns) const final {
34 populateFuncToEmitCPatterns(typeConverter, patterns);
35 }
36};
37} // namespace
38
39void mlir::registerConvertFuncToEmitCInterface(DialectRegistry &registry) {
40 registry.addExtension(extensionFn: +[](MLIRContext *ctx, func::FuncDialect *dialect) {
41 dialect->addInterfaces<FuncToEmitCDialectInterface>();
42 });
43}
44
45//===----------------------------------------------------------------------===//
46// Conversion Patterns
47//===----------------------------------------------------------------------===//
48
49namespace {
50class CallOpConversion final : public OpConversionPattern<func::CallOp> {
51public:
52 using OpConversionPattern<func::CallOp>::OpConversionPattern;
53
54 LogicalResult
55 matchAndRewrite(func::CallOp callOp, OpAdaptor adaptor,
56 ConversionPatternRewriter &rewriter) const override {
57 // Multiple results func cannot be converted to `emitc.func`.
58 if (callOp.getNumResults() > 1)
59 return rewriter.notifyMatchFailure(
60 callOp, "only functions with zero or one result can be converted");
61
62 rewriter.replaceOpWithNewOp<emitc::CallOp>(callOp, callOp.getResultTypes(),
63 adaptor.getOperands(),
64 callOp->getAttrs());
65
66 return success();
67 }
68};
69
70class FuncOpConversion final : public OpConversionPattern<func::FuncOp> {
71public:
72 using OpConversionPattern<func::FuncOp>::OpConversionPattern;
73
74 LogicalResult
75 matchAndRewrite(func::FuncOp funcOp, OpAdaptor adaptor,
76 ConversionPatternRewriter &rewriter) const override {
77 FunctionType fnType = funcOp.getFunctionType();
78
79 if (fnType.getNumResults() > 1)
80 return rewriter.notifyMatchFailure(
81 funcOp, "only functions with zero or one result can be converted");
82
83 TypeConverter::SignatureConversion signatureConverter(
84 fnType.getNumInputs());
85 for (const auto &argType : enumerate(fnType.getInputs())) {
86 auto convertedType = getTypeConverter()->convertType(argType.value());
87 if (!convertedType)
88 return rewriter.notifyMatchFailure(funcOp,
89 "argument type conversion failed");
90 signatureConverter.addInputs(argType.index(), convertedType);
91 }
92
93 Type resultType;
94 if (fnType.getNumResults() == 1) {
95 resultType = getTypeConverter()->convertType(fnType.getResult(0));
96 if (!resultType)
97 return rewriter.notifyMatchFailure(funcOp,
98 "result type conversion failed");
99 }
100
101 // Create the converted `emitc.func` op.
102 emitc::FuncOp newFuncOp = rewriter.create<emitc::FuncOp>(
103 funcOp.getLoc(), funcOp.getName(),
104 FunctionType::get(rewriter.getContext(),
105 signatureConverter.getConvertedTypes(),
106 resultType ? TypeRange(resultType) : TypeRange()));
107
108 // Copy over all attributes other than the function name and type.
109 for (const auto &namedAttr : funcOp->getAttrs()) {
110 if (namedAttr.getName() != funcOp.getFunctionTypeAttrName() &&
111 namedAttr.getName() != SymbolTable::getSymbolAttrName())
112 newFuncOp->setAttr(namedAttr.getName(), namedAttr.getValue());
113 }
114
115 // Add `extern` to specifiers if `func.func` is declaration only.
116 if (funcOp.isDeclaration()) {
117 ArrayAttr specifiers = rewriter.getStrArrayAttr({"extern"});
118 newFuncOp.setSpecifiersAttr(specifiers);
119 }
120
121 // Add `static` to specifiers if `func.func` is private but not a
122 // declaration.
123 if (funcOp.isPrivate() && !funcOp.isDeclaration()) {
124 ArrayAttr specifiers = rewriter.getStrArrayAttr({"static"});
125 newFuncOp.setSpecifiersAttr(specifiers);
126 }
127
128 if (!funcOp.isDeclaration()) {
129 rewriter.inlineRegionBefore(funcOp.getBody(), newFuncOp.getBody(),
130 newFuncOp.end());
131 if (failed(rewriter.convertRegionTypes(
132 region: &newFuncOp.getBody(), converter: *getTypeConverter(), entryConversion: &signatureConverter)))
133 return failure();
134 }
135 rewriter.eraseOp(op: funcOp);
136
137 return success();
138 }
139};
140
141class ReturnOpConversion final : public OpConversionPattern<func::ReturnOp> {
142public:
143 using OpConversionPattern<func::ReturnOp>::OpConversionPattern;
144
145 LogicalResult
146 matchAndRewrite(func::ReturnOp returnOp, OpAdaptor adaptor,
147 ConversionPatternRewriter &rewriter) const override {
148 if (returnOp.getNumOperands() > 1)
149 return rewriter.notifyMatchFailure(
150 returnOp, "only zero or one operand is supported");
151
152 rewriter.replaceOpWithNewOp<emitc::ReturnOp>(
153 returnOp,
154 returnOp.getNumOperands() ? adaptor.getOperands()[0] : nullptr);
155 return success();
156 }
157};
158} // namespace
159
160//===----------------------------------------------------------------------===//
161// Pattern population
162//===----------------------------------------------------------------------===//
163
164void mlir::populateFuncToEmitCPatterns(const TypeConverter &typeConverter,
165 RewritePatternSet &patterns) {
166 MLIRContext *ctx = patterns.getContext();
167
168 patterns.add<CallOpConversion, FuncOpConversion, ReturnOpConversion>(
169 arg: typeConverter, args&: ctx);
170}
171

source code of mlir/lib/Conversion/FuncToEmitC/FuncToEmitC.cpp