xref: /llvm-project/mlir/lib/Conversion/ComplexToLibm/ComplexToLibm.cpp (revision 039b969b32b64b64123dce30dd28ec4e343d893f)
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 "../PassDetail.h"
12 #include "mlir/Dialect/Complex/IR/Complex.h"
13 #include "mlir/Dialect/Func/IR/FuncOps.h"
14 #include "mlir/IR/PatternMatch.h"
15 
16 using namespace mlir;
17 
18 namespace {
19 // Functor to resolve the function name corresponding to the given complex
20 // result type.
21 struct ComplexTypeResolver {
22   llvm::Optional<bool> operator()(Type type) const {
23     auto complexType = type.cast<ComplexType>();
24     auto elementType = complexType.getElementType();
25     if (!elementType.isa<Float32Type, Float64Type>())
26       return {};
27 
28     return elementType.getIntOrFloatBitWidth() == 64;
29   }
30 };
31 
32 // Functor to resolve the function name corresponding to the given float result
33 // type.
34 struct FloatTypeResolver {
35   llvm::Optional<bool> operator()(Type type) const {
36     auto elementType = type.cast<FloatType>();
37     if (!elementType.isa<Float32Type, Float64Type>())
38       return {};
39 
40     return elementType.getIntOrFloatBitWidth() == 64;
41   }
42 };
43 
44 // Pattern to convert scalar complex operations to calls to libm functions.
45 // Additionally the libm function signatures are declared.
46 // TypeResolver is a functor returning the libm function name according to the
47 // expected type double or float.
48 template <typename Op, typename TypeResolver = ComplexTypeResolver>
49 struct ScalarOpToLibmCall : public OpRewritePattern<Op> {
50 public:
51   using OpRewritePattern<Op>::OpRewritePattern;
52   ScalarOpToLibmCall<Op, TypeResolver>(MLIRContext *context,
53                                        StringRef floatFunc,
54                                        StringRef doubleFunc,
55                                        PatternBenefit benefit)
56       : OpRewritePattern<Op>(context, benefit), floatFunc(floatFunc),
57         doubleFunc(doubleFunc){};
58 
59   LogicalResult matchAndRewrite(Op op, PatternRewriter &rewriter) const final;
60 
61 private:
62   std::string floatFunc, doubleFunc;
63 };
64 } // namespace
65 
66 template <typename Op, typename TypeResolver>
67 LogicalResult ScalarOpToLibmCall<Op, TypeResolver>::matchAndRewrite(
68     Op op, PatternRewriter &rewriter) const {
69   auto module = SymbolTable::getNearestSymbolTable(op);
70   auto isDouble = TypeResolver()(op.getType());
71   if (!isDouble.has_value())
72     return failure();
73 
74   auto name = isDouble.value() ? doubleFunc : floatFunc;
75 
76   auto opFunc = dyn_cast_or_null<SymbolOpInterface>(
77       SymbolTable::lookupSymbolIn(module, name));
78   // Forward declare function if it hasn't already been
79   if (!opFunc) {
80     OpBuilder::InsertionGuard guard(rewriter);
81     rewriter.setInsertionPointToStart(&module->getRegion(0).front());
82     auto opFunctionTy = FunctionType::get(
83         rewriter.getContext(), op->getOperandTypes(), op->getResultTypes());
84     opFunc = rewriter.create<func::FuncOp>(rewriter.getUnknownLoc(), name,
85                                            opFunctionTy);
86     opFunc.setPrivate();
87   }
88   assert(isa<FunctionOpInterface>(SymbolTable::lookupSymbolIn(module, name)));
89 
90   rewriter.replaceOpWithNewOp<func::CallOp>(op, name, op.getType(),
91                                             op->getOperands());
92 
93   return success();
94 }
95 
96 void mlir::populateComplexToLibmConversionPatterns(RewritePatternSet &patterns,
97                                                    PatternBenefit benefit) {
98   patterns.add<ScalarOpToLibmCall<complex::PowOp>>(patterns.getContext(),
99                                                    "cpowf", "cpow", benefit);
100   patterns.add<ScalarOpToLibmCall<complex::SqrtOp>>(patterns.getContext(),
101                                                     "csqrtf", "csqrt", benefit);
102   patterns.add<ScalarOpToLibmCall<complex::TanhOp>>(patterns.getContext(),
103                                                     "ctanhf", "ctanh", benefit);
104   patterns.add<ScalarOpToLibmCall<complex::CosOp>>(patterns.getContext(),
105                                                    "ccosf", "ccos", benefit);
106   patterns.add<ScalarOpToLibmCall<complex::SinOp>>(patterns.getContext(),
107                                                    "csinf", "csin", benefit);
108   patterns.add<ScalarOpToLibmCall<complex::ConjOp>>(patterns.getContext(),
109                                                     "conjf", "conj", benefit);
110   patterns.add<ScalarOpToLibmCall<complex::LogOp>>(patterns.getContext(),
111                                                    "clogf", "clog", benefit);
112   patterns.add<ScalarOpToLibmCall<complex::AbsOp, FloatTypeResolver>>(
113       patterns.getContext(), "cabsf", "cabs", benefit);
114   patterns.add<ScalarOpToLibmCall<complex::AngleOp, FloatTypeResolver>>(
115       patterns.getContext(), "cargf", "carg", benefit);
116 }
117 
118 namespace {
119 struct ConvertComplexToLibmPass
120     : public ConvertComplexToLibmBase<ConvertComplexToLibmPass> {
121   void runOnOperation() override;
122 };
123 } // namespace
124 
125 void ConvertComplexToLibmPass::runOnOperation() {
126   auto module = getOperation();
127 
128   RewritePatternSet patterns(&getContext());
129   populateComplexToLibmConversionPatterns(patterns, /*benefit=*/1);
130 
131   ConversionTarget target(getContext());
132   target.addLegalDialect<func::FuncDialect>();
133   target.addIllegalOp<complex::PowOp, complex::SqrtOp, complex::TanhOp,
134                       complex::CosOp, complex::SinOp, complex::ConjOp,
135                       complex::LogOp, complex::AbsOp, complex::AngleOp>();
136   if (failed(applyPartialConversion(module, target, std::move(patterns))))
137     signalPassFailure();
138 }
139 
140 std::unique_ptr<OperationPass<ModuleOp>>
141 mlir::createConvertComplexToLibmPass() {
142   return std::make_unique<ConvertComplexToLibmPass>();
143 }
144