xref: /llvm-project/mlir/lib/Conversion/ComplexToLibm/ComplexToLibm.cpp (revision 2be8af8f0e0780901213b6fd3013a5268ddc3359)
1 //===-- ComplexToLibm.cpp - conversion from Complex to libm calls ---------===//
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 #include "mlir/Conversion/ComplexToLibm/ComplexToLibm.h"
10 
11 #include "mlir/Dialect/Complex/IR/Complex.h"
12 #include "mlir/Dialect/Func/IR/FuncOps.h"
13 #include "mlir/IR/PatternMatch.h"
14 #include "mlir/Pass/Pass.h"
15 
16 namespace mlir {
17 #define GEN_PASS_DEF_CONVERTCOMPLEXTOLIBMPASS
18 #include "mlir/Conversion/Passes.h.inc"
19 } // namespace mlir
20 
21 using namespace mlir;
22 
23 namespace {
24 // Functor to resolve the function name corresponding to the given complex
25 // result type.
26 struct ComplexTypeResolver {
27   llvm::Optional<bool> operator()(Type type) const {
28     auto complexType = type.cast<ComplexType>();
29     auto elementType = complexType.getElementType();
30     if (!elementType.isa<Float32Type, Float64Type>())
31       return {};
32 
33     return elementType.getIntOrFloatBitWidth() == 64;
34   }
35 };
36 
37 // Functor to resolve the function name corresponding to the given float result
38 // type.
39 struct FloatTypeResolver {
40   llvm::Optional<bool> operator()(Type type) const {
41     auto elementType = type.cast<FloatType>();
42     if (!elementType.isa<Float32Type, Float64Type>())
43       return {};
44 
45     return elementType.getIntOrFloatBitWidth() == 64;
46   }
47 };
48 
49 // Pattern to convert scalar complex operations to calls to libm functions.
50 // Additionally the libm function signatures are declared.
51 // TypeResolver is a functor returning the libm function name according to the
52 // expected type double or float.
53 template <typename Op, typename TypeResolver = ComplexTypeResolver>
54 struct ScalarOpToLibmCall : public OpRewritePattern<Op> {
55 public:
56   using OpRewritePattern<Op>::OpRewritePattern;
57   ScalarOpToLibmCall<Op, TypeResolver>(MLIRContext *context,
58                                        StringRef floatFunc,
59                                        StringRef doubleFunc,
60                                        PatternBenefit benefit)
61       : OpRewritePattern<Op>(context, benefit), floatFunc(floatFunc),
62         doubleFunc(doubleFunc){};
63 
64   LogicalResult matchAndRewrite(Op op, PatternRewriter &rewriter) const final;
65 
66 private:
67   std::string floatFunc, doubleFunc;
68 };
69 } // namespace
70 
71 template <typename Op, typename TypeResolver>
72 LogicalResult ScalarOpToLibmCall<Op, TypeResolver>::matchAndRewrite(
73     Op op, PatternRewriter &rewriter) const {
74   auto module = SymbolTable::getNearestSymbolTable(op);
75   auto isDouble = TypeResolver()(op.getType());
76   if (!isDouble.has_value())
77     return failure();
78 
79   auto name = isDouble.value() ? doubleFunc : floatFunc;
80 
81   auto opFunc = dyn_cast_or_null<SymbolOpInterface>(
82       SymbolTable::lookupSymbolIn(module, name));
83   // Forward declare function if it hasn't already been
84   if (!opFunc) {
85     OpBuilder::InsertionGuard guard(rewriter);
86     rewriter.setInsertionPointToStart(&module->getRegion(0).front());
87     auto opFunctionTy = FunctionType::get(
88         rewriter.getContext(), op->getOperandTypes(), op->getResultTypes());
89     opFunc = rewriter.create<func::FuncOp>(rewriter.getUnknownLoc(), name,
90                                            opFunctionTy);
91     opFunc.setPrivate();
92   }
93   assert(isa<FunctionOpInterface>(SymbolTable::lookupSymbolIn(module, name)));
94 
95   rewriter.replaceOpWithNewOp<func::CallOp>(op, name, op.getType(),
96                                             op->getOperands());
97 
98   return success();
99 }
100 
101 void mlir::populateComplexToLibmConversionPatterns(RewritePatternSet &patterns,
102                                                    PatternBenefit benefit) {
103   patterns.add<ScalarOpToLibmCall<complex::PowOp>>(patterns.getContext(),
104                                                    "cpowf", "cpow", benefit);
105   patterns.add<ScalarOpToLibmCall<complex::SqrtOp>>(patterns.getContext(),
106                                                     "csqrtf", "csqrt", benefit);
107   patterns.add<ScalarOpToLibmCall<complex::TanhOp>>(patterns.getContext(),
108                                                     "ctanhf", "ctanh", benefit);
109   patterns.add<ScalarOpToLibmCall<complex::CosOp>>(patterns.getContext(),
110                                                    "ccosf", "ccos", benefit);
111   patterns.add<ScalarOpToLibmCall<complex::SinOp>>(patterns.getContext(),
112                                                    "csinf", "csin", benefit);
113   patterns.add<ScalarOpToLibmCall<complex::ConjOp>>(patterns.getContext(),
114                                                     "conjf", "conj", benefit);
115   patterns.add<ScalarOpToLibmCall<complex::LogOp>>(patterns.getContext(),
116                                                    "clogf", "clog", benefit);
117   patterns.add<ScalarOpToLibmCall<complex::AbsOp, FloatTypeResolver>>(
118       patterns.getContext(), "cabsf", "cabs", benefit);
119   patterns.add<ScalarOpToLibmCall<complex::AngleOp, FloatTypeResolver>>(
120       patterns.getContext(), "cargf", "carg", benefit);
121 }
122 
123 namespace {
124 struct ConvertComplexToLibmPass
125     : public impl::ConvertComplexToLibmPassBase<ConvertComplexToLibmPass> {
126   using ConvertComplexToLibmPassBase::ConvertComplexToLibmPassBase;
127 
128   void runOnOperation() override;
129 };
130 } // namespace
131 
132 void ConvertComplexToLibmPass::runOnOperation() {
133   auto module = getOperation();
134 
135   RewritePatternSet patterns(&getContext());
136   populateComplexToLibmConversionPatterns(patterns, /*benefit=*/1);
137 
138   ConversionTarget target(getContext());
139   target.addLegalDialect<func::FuncDialect>();
140   target.addIllegalOp<complex::PowOp, complex::SqrtOp, complex::TanhOp,
141                       complex::CosOp, complex::SinOp, complex::ConjOp,
142                       complex::LogOp, complex::AbsOp, complex::AngleOp>();
143   if (failed(applyPartialConversion(module, target, std::move(patterns))))
144     signalPassFailure();
145 }
146 
147 std::unique_ptr<OperationPass<ModuleOp>>
148 mlir::createConvertComplexToLibmPass() {
149   return std::make_unique<ConvertComplexToLibmPass>();
150 }
151