xref: /llvm-project/mlir/lib/Conversion/ComplexToLibm/ComplexToLibm.cpp (revision 1adfdab39936e3fe6f4b7bca945f3d46b4b075e3)
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 #include <optional>
16 
17 namespace mlir {
18 #define GEN_PASS_DEF_CONVERTCOMPLEXTOLIBM
19 #include "mlir/Conversion/Passes.h.inc"
20 } // namespace mlir
21 
22 using namespace mlir;
23 
24 namespace {
25 // Functor to resolve the function name corresponding to the given complex
26 // result type.
27 struct ComplexTypeResolver {
28   std::optional<bool> operator()(Type type) const {
29     auto complexType = type.cast<ComplexType>();
30     auto elementType = complexType.getElementType();
31     if (!elementType.isa<Float32Type, Float64Type>())
32       return {};
33 
34     return elementType.getIntOrFloatBitWidth() == 64;
35   }
36 };
37 
38 // Functor to resolve the function name corresponding to the given float result
39 // type.
40 struct FloatTypeResolver {
41   std::optional<bool> operator()(Type type) const {
42     auto elementType = type.cast<FloatType>();
43     if (!elementType.isa<Float32Type, Float64Type>())
44       return {};
45 
46     return elementType.getIntOrFloatBitWidth() == 64;
47   }
48 };
49 
50 // Pattern to convert scalar complex operations to calls to libm functions.
51 // Additionally the libm function signatures are declared.
52 // TypeResolver is a functor returning the libm function name according to the
53 // expected type double or float.
54 template <typename Op, typename TypeResolver = ComplexTypeResolver>
55 struct ScalarOpToLibmCall : public OpRewritePattern<Op> {
56 public:
57   using OpRewritePattern<Op>::OpRewritePattern;
58   ScalarOpToLibmCall<Op, TypeResolver>(MLIRContext *context,
59                                        StringRef floatFunc,
60                                        StringRef doubleFunc,
61                                        PatternBenefit benefit)
62       : OpRewritePattern<Op>(context, benefit), floatFunc(floatFunc),
63         doubleFunc(doubleFunc){};
64 
65   LogicalResult matchAndRewrite(Op op, PatternRewriter &rewriter) const final;
66 
67 private:
68   std::string floatFunc, doubleFunc;
69 };
70 } // namespace
71 
72 template <typename Op, typename TypeResolver>
73 LogicalResult ScalarOpToLibmCall<Op, TypeResolver>::matchAndRewrite(
74     Op op, PatternRewriter &rewriter) const {
75   auto module = SymbolTable::getNearestSymbolTable(op);
76   auto isDouble = TypeResolver()(op.getType());
77   if (!isDouble.has_value())
78     return failure();
79 
80   auto name = isDouble.value() ? doubleFunc : floatFunc;
81 
82   auto opFunc = dyn_cast_or_null<SymbolOpInterface>(
83       SymbolTable::lookupSymbolIn(module, name));
84   // Forward declare function if it hasn't already been
85   if (!opFunc) {
86     OpBuilder::InsertionGuard guard(rewriter);
87     rewriter.setInsertionPointToStart(&module->getRegion(0).front());
88     auto opFunctionTy = FunctionType::get(
89         rewriter.getContext(), op->getOperandTypes(), op->getResultTypes());
90     opFunc = rewriter.create<func::FuncOp>(rewriter.getUnknownLoc(), name,
91                                            opFunctionTy);
92     opFunc.setPrivate();
93   }
94   assert(isa<FunctionOpInterface>(SymbolTable::lookupSymbolIn(module, name)));
95 
96   rewriter.replaceOpWithNewOp<func::CallOp>(op, name, op.getType(),
97                                             op->getOperands());
98 
99   return success();
100 }
101 
102 void mlir::populateComplexToLibmConversionPatterns(RewritePatternSet &patterns,
103                                                    PatternBenefit benefit) {
104   patterns.add<ScalarOpToLibmCall<complex::PowOp>>(patterns.getContext(),
105                                                    "cpowf", "cpow", benefit);
106   patterns.add<ScalarOpToLibmCall<complex::SqrtOp>>(patterns.getContext(),
107                                                     "csqrtf", "csqrt", benefit);
108   patterns.add<ScalarOpToLibmCall<complex::TanhOp>>(patterns.getContext(),
109                                                     "ctanhf", "ctanh", benefit);
110   patterns.add<ScalarOpToLibmCall<complex::CosOp>>(patterns.getContext(),
111                                                    "ccosf", "ccos", benefit);
112   patterns.add<ScalarOpToLibmCall<complex::SinOp>>(patterns.getContext(),
113                                                    "csinf", "csin", benefit);
114   patterns.add<ScalarOpToLibmCall<complex::ConjOp>>(patterns.getContext(),
115                                                     "conjf", "conj", benefit);
116   patterns.add<ScalarOpToLibmCall<complex::LogOp>>(patterns.getContext(),
117                                                    "clogf", "clog", benefit);
118   patterns.add<ScalarOpToLibmCall<complex::AbsOp, FloatTypeResolver>>(
119       patterns.getContext(), "cabsf", "cabs", benefit);
120   patterns.add<ScalarOpToLibmCall<complex::AngleOp, FloatTypeResolver>>(
121       patterns.getContext(), "cargf", "carg", benefit);
122 }
123 
124 namespace {
125 struct ConvertComplexToLibmPass
126     : public impl::ConvertComplexToLibmBase<ConvertComplexToLibmPass> {
127   void runOnOperation() override;
128 };
129 } // namespace
130 
131 void ConvertComplexToLibmPass::runOnOperation() {
132   auto module = getOperation();
133 
134   RewritePatternSet patterns(&getContext());
135   populateComplexToLibmConversionPatterns(patterns, /*benefit=*/1);
136 
137   ConversionTarget target(getContext());
138   target.addLegalDialect<func::FuncDialect>();
139   target.addIllegalOp<complex::PowOp, complex::SqrtOp, complex::TanhOp,
140                       complex::CosOp, complex::SinOp, complex::ConjOp,
141                       complex::LogOp, complex::AbsOp, complex::AngleOp>();
142   if (failed(applyPartialConversion(module, target, std::move(patterns))))
143     signalPassFailure();
144 }
145 
146 std::unique_ptr<OperationPass<ModuleOp>>
147 mlir::createConvertComplexToLibmPass() {
148   return std::make_unique<ConvertComplexToLibmPass>();
149 }
150