1 //===-- BoxedProcedure.cpp ------------------------------------------------===// 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 "PassDetail.h" 10 #include "flang/Optimizer/Builder/FIRBuilder.h" 11 #include "flang/Optimizer/Builder/LowLevelIntrinsics.h" 12 #include "flang/Optimizer/CodeGen/CodeGen.h" 13 #include "flang/Optimizer/Dialect/FIRDialect.h" 14 #include "flang/Optimizer/Dialect/FIROps.h" 15 #include "flang/Optimizer/Dialect/FIRType.h" 16 #include "flang/Optimizer/Support/FIRContext.h" 17 #include "flang/Optimizer/Support/FatalError.h" 18 #include "mlir/IR/PatternMatch.h" 19 #include "mlir/Pass/Pass.h" 20 #include "mlir/Transforms/DialectConversion.h" 21 22 #define DEBUG_TYPE "flang-procedure-pointer" 23 24 using namespace fir; 25 26 namespace { 27 /// Options to the procedure pointer pass. 28 struct BoxedProcedureOptions { 29 // Lower the boxproc abstraction to function pointers and thunks where 30 // required. 31 bool useThunks = true; 32 }; 33 34 /// This type converter rewrites all `!fir.boxproc<Func>` types to `Func` types. 35 class BoxprocTypeRewriter : public mlir::TypeConverter { 36 public: 37 using mlir::TypeConverter::convertType; 38 39 /// Does the type \p ty need to be converted? 40 /// Any type that is a `!fir.boxproc` in whole or in part will need to be 41 /// converted to a function type to lower the IR to function pointer form in 42 /// the default implementation performed in this pass. Other implementations 43 /// are possible, so those may convert `!fir.boxproc` to some other type or 44 /// not at all depending on the implementation target's characteristics and 45 /// preference. 46 bool needsConversion(mlir::Type ty) { 47 if (ty.isa<BoxProcType>()) 48 return true; 49 if (auto funcTy = ty.dyn_cast<mlir::FunctionType>()) { 50 for (auto t : funcTy.getInputs()) 51 if (needsConversion(t)) 52 return true; 53 for (auto t : funcTy.getResults()) 54 if (needsConversion(t)) 55 return true; 56 return false; 57 } 58 if (auto tupleTy = ty.dyn_cast<mlir::TupleType>()) { 59 for (auto t : tupleTy.getTypes()) 60 if (needsConversion(t)) 61 return true; 62 return false; 63 } 64 if (auto recTy = ty.dyn_cast<RecordType>()) { 65 if (llvm::is_contained(visitedTypes, recTy)) 66 return false; 67 bool result = false; 68 visitedTypes.push_back(recTy); 69 for (auto t : recTy.getTypeList()) { 70 if (needsConversion(t.second)) { 71 result = true; 72 break; 73 } 74 } 75 visitedTypes.pop_back(); 76 return result; 77 } 78 if (auto boxTy = ty.dyn_cast<BoxType>()) 79 return needsConversion(boxTy.getEleTy()); 80 if (isa_ref_type(ty)) 81 return needsConversion(unwrapRefType(ty)); 82 if (auto t = ty.dyn_cast<SequenceType>()) 83 return needsConversion(unwrapSequenceType(ty)); 84 return false; 85 } 86 87 BoxprocTypeRewriter(mlir::Location location) : loc{location} { 88 addConversion([](mlir::Type ty) { return ty; }); 89 addConversion( 90 [&](BoxProcType boxproc) { return convertType(boxproc.getEleTy()); }); 91 addConversion([&](mlir::TupleType tupTy) { 92 llvm::SmallVector<mlir::Type> memTys; 93 for (auto ty : tupTy.getTypes()) 94 memTys.push_back(convertType(ty)); 95 return mlir::TupleType::get(tupTy.getContext(), memTys); 96 }); 97 addConversion([&](mlir::FunctionType funcTy) { 98 llvm::SmallVector<mlir::Type> inTys; 99 llvm::SmallVector<mlir::Type> resTys; 100 for (auto ty : funcTy.getInputs()) 101 inTys.push_back(convertType(ty)); 102 for (auto ty : funcTy.getResults()) 103 resTys.push_back(convertType(ty)); 104 return mlir::FunctionType::get(funcTy.getContext(), inTys, resTys); 105 }); 106 addConversion([&](ReferenceType ty) { 107 return ReferenceType::get(convertType(ty.getEleTy())); 108 }); 109 addConversion([&](PointerType ty) { 110 return PointerType::get(convertType(ty.getEleTy())); 111 }); 112 addConversion( 113 [&](HeapType ty) { return HeapType::get(convertType(ty.getEleTy())); }); 114 addConversion( 115 [&](BoxType ty) { return BoxType::get(convertType(ty.getEleTy())); }); 116 addConversion([&](SequenceType ty) { 117 // TODO: add ty.getLayoutMap() as needed. 118 return SequenceType::get(ty.getShape(), convertType(ty.getEleTy())); 119 }); 120 addConversion([&](RecordType ty) -> mlir::Type { 121 if (!needsConversion(ty)) 122 return ty; 123 // FIR record types can have recursive references, so conversion is a bit 124 // more complex than the other types. This conversion is not needed 125 // presently, so just emit a TODO message. Need to consider the uniqued 126 // name of the record, etc. Also, fir::RecordType::get returns the 127 // existing type being translated. So finalize() will not change it, and 128 // the translation would not do anything. So the type needs to be mutated, 129 // and this might require special care to comply with MLIR infrastructure. 130 131 // TODO: this will be needed to support derived type containing procedure 132 // pointer components. 133 fir::emitFatalError( 134 loc, "not yet implemented: record type with a boxproc type"); 135 return RecordType::get(ty.getContext(), "*fixme*"); 136 }); 137 addArgumentMaterialization(materializeProcedure); 138 addSourceMaterialization(materializeProcedure); 139 addTargetMaterialization(materializeProcedure); 140 } 141 142 static mlir::Value materializeProcedure(mlir::OpBuilder &builder, 143 BoxProcType type, 144 mlir::ValueRange inputs, 145 mlir::Location loc) { 146 assert(inputs.size() == 1); 147 return builder.create<ConvertOp>(loc, unwrapRefType(type.getEleTy()), 148 inputs[0]); 149 } 150 151 void setLocation(mlir::Location location) { loc = location; } 152 153 private: 154 llvm::SmallVector<mlir::Type> visitedTypes; 155 mlir::Location loc; 156 }; 157 158 /// A `boxproc` is an abstraction for a Fortran procedure reference. Typically, 159 /// Fortran procedures can be referenced directly through a function pointer. 160 /// However, Fortran has one-level dynamic scoping between a host procedure and 161 /// its internal procedures. This allows internal procedures to directly access 162 /// and modify the state of the host procedure's variables. 163 /// 164 /// There are any number of possible implementations possible. 165 /// 166 /// The implementation used here is to convert `boxproc` values to function 167 /// pointers everywhere. If a `boxproc` value includes a frame pointer to the 168 /// host procedure's data, then a thunk will be created at runtime to capture 169 /// the frame pointer during execution. In LLVM IR, the frame pointer is 170 /// designated with the `nest` attribute. The thunk's address will then be used 171 /// as the call target instead of the original function's address directly. 172 class BoxedProcedurePass : public BoxedProcedurePassBase<BoxedProcedurePass> { 173 public: 174 BoxedProcedurePass() { options = {true}; } 175 BoxedProcedurePass(bool useThunks) { options = {useThunks}; } 176 177 inline mlir::ModuleOp getModule() { return getOperation(); } 178 179 void runOnOperation() override final { 180 if (options.useThunks) { 181 auto *context = &getContext(); 182 mlir::IRRewriter rewriter(context); 183 BoxprocTypeRewriter typeConverter(mlir::UnknownLoc::get(context)); 184 mlir::Dialect *firDialect = context->getLoadedDialect("fir"); 185 getModule().walk([&](mlir::Operation *op) { 186 typeConverter.setLocation(op->getLoc()); 187 if (auto addr = mlir::dyn_cast<BoxAddrOp>(op)) { 188 auto ty = addr.getVal().getType(); 189 if (typeConverter.needsConversion(ty) || 190 ty.isa<mlir::FunctionType>()) { 191 // Rewrite all `fir.box_addr` ops on values of type `!fir.boxproc` 192 // or function type to be `fir.convert` ops. 193 rewriter.setInsertionPoint(addr); 194 rewriter.replaceOpWithNewOp<ConvertOp>( 195 addr, typeConverter.convertType(addr.getType()), addr.getVal()); 196 } 197 } else if (auto func = mlir::dyn_cast<mlir::func::FuncOp>(op)) { 198 mlir::FunctionType ty = func.getFunctionType(); 199 if (typeConverter.needsConversion(ty)) { 200 rewriter.startRootUpdate(func); 201 auto toTy = 202 typeConverter.convertType(ty).cast<mlir::FunctionType>(); 203 if (!func.empty()) 204 for (auto e : llvm::enumerate(toTy.getInputs())) { 205 unsigned i = e.index(); 206 auto &block = func.front(); 207 block.insertArgument(i, e.value(), func.getLoc()); 208 block.getArgument(i + 1).replaceAllUsesWith( 209 block.getArgument(i)); 210 block.eraseArgument(i + 1); 211 } 212 func.setType(toTy); 213 rewriter.finalizeRootUpdate(func); 214 } 215 } else if (auto embox = mlir::dyn_cast<EmboxProcOp>(op)) { 216 // Rewrite all `fir.emboxproc` ops to either `fir.convert` or a thunk 217 // as required. 218 mlir::Type toTy = embox.getType().cast<BoxProcType>().getEleTy(); 219 rewriter.setInsertionPoint(embox); 220 if (embox.getHost()) { 221 // Create the thunk. 222 auto module = embox->getParentOfType<mlir::ModuleOp>(); 223 fir::KindMapping kindMap = getKindMapping(module); 224 FirOpBuilder builder(rewriter, kindMap); 225 auto loc = embox.getLoc(); 226 mlir::Type i8Ty = builder.getI8Type(); 227 mlir::Type i8Ptr = builder.getRefType(i8Ty); 228 mlir::Type buffTy = SequenceType::get({32}, i8Ty); 229 auto buffer = builder.create<AllocaOp>(loc, buffTy); 230 mlir::Value closure = 231 builder.createConvert(loc, i8Ptr, embox.getHost()); 232 mlir::Value tramp = builder.createConvert(loc, i8Ptr, buffer); 233 mlir::Value func = 234 builder.createConvert(loc, i8Ptr, embox.getFunc()); 235 builder.create<fir::CallOp>( 236 loc, factory::getLlvmInitTrampoline(builder), 237 llvm::ArrayRef<mlir::Value>{tramp, func, closure}); 238 auto adjustCall = builder.create<fir::CallOp>( 239 loc, factory::getLlvmAdjustTrampoline(builder), 240 llvm::ArrayRef<mlir::Value>{tramp}); 241 rewriter.replaceOpWithNewOp<ConvertOp>(embox, toTy, 242 adjustCall.getResult(0)); 243 } else { 244 // Just forward the function as a pointer. 245 rewriter.replaceOpWithNewOp<ConvertOp>(embox, toTy, 246 embox.getFunc()); 247 } 248 } else if (auto mem = mlir::dyn_cast<AllocaOp>(op)) { 249 auto ty = mem.getType(); 250 if (typeConverter.needsConversion(ty)) { 251 rewriter.setInsertionPoint(mem); 252 auto toTy = typeConverter.convertType(unwrapRefType(ty)); 253 bool isPinned = mem.getPinned(); 254 llvm::StringRef uniqName = 255 mem.getUniqName().value_or(llvm::StringRef()); 256 llvm::StringRef bindcName = 257 mem.getBindcName().value_or(llvm::StringRef()); 258 rewriter.replaceOpWithNewOp<AllocaOp>( 259 mem, toTy, uniqName, bindcName, isPinned, mem.getTypeparams(), 260 mem.getShape()); 261 } 262 } else if (auto mem = mlir::dyn_cast<AllocMemOp>(op)) { 263 auto ty = mem.getType(); 264 if (typeConverter.needsConversion(ty)) { 265 rewriter.setInsertionPoint(mem); 266 auto toTy = typeConverter.convertType(unwrapRefType(ty)); 267 llvm::StringRef uniqName = 268 mem.getUniqName().value_or(llvm::StringRef()); 269 llvm::StringRef bindcName = 270 mem.getBindcName().value_or(llvm::StringRef()); 271 rewriter.replaceOpWithNewOp<AllocMemOp>( 272 mem, toTy, uniqName, bindcName, mem.getTypeparams(), 273 mem.getShape()); 274 } 275 } else if (auto coor = mlir::dyn_cast<CoordinateOp>(op)) { 276 auto ty = coor.getType(); 277 mlir::Type baseTy = coor.getBaseType(); 278 if (typeConverter.needsConversion(ty) || 279 typeConverter.needsConversion(baseTy)) { 280 rewriter.setInsertionPoint(coor); 281 auto toTy = typeConverter.convertType(ty); 282 auto toBaseTy = typeConverter.convertType(baseTy); 283 rewriter.replaceOpWithNewOp<CoordinateOp>(coor, toTy, coor.getRef(), 284 coor.getCoor(), toBaseTy); 285 } 286 } else if (auto index = mlir::dyn_cast<FieldIndexOp>(op)) { 287 auto ty = index.getType(); 288 mlir::Type onTy = index.getOnType(); 289 if (typeConverter.needsConversion(ty) || 290 typeConverter.needsConversion(onTy)) { 291 rewriter.setInsertionPoint(index); 292 auto toTy = typeConverter.convertType(ty); 293 auto toOnTy = typeConverter.convertType(onTy); 294 rewriter.replaceOpWithNewOp<FieldIndexOp>( 295 index, toTy, index.getFieldId(), toOnTy, index.getTypeparams()); 296 } 297 } else if (auto index = mlir::dyn_cast<LenParamIndexOp>(op)) { 298 auto ty = index.getType(); 299 mlir::Type onTy = index.getOnType(); 300 if (typeConverter.needsConversion(ty) || 301 typeConverter.needsConversion(onTy)) { 302 rewriter.setInsertionPoint(index); 303 auto toTy = typeConverter.convertType(ty); 304 auto toOnTy = typeConverter.convertType(onTy); 305 rewriter.replaceOpWithNewOp<LenParamIndexOp>( 306 mem, toTy, index.getFieldId(), toOnTy, index.getTypeparams()); 307 } 308 } else if (op->getDialect() == firDialect) { 309 rewriter.startRootUpdate(op); 310 for (auto i : llvm::enumerate(op->getResultTypes())) 311 if (typeConverter.needsConversion(i.value())) { 312 auto toTy = typeConverter.convertType(i.value()); 313 op->getResult(i.index()).setType(toTy); 314 } 315 rewriter.finalizeRootUpdate(op); 316 } 317 }); 318 } 319 // TODO: any alternative implementation. Note: currently, the default code 320 // gen will not be able to handle boxproc and will give an error. 321 } 322 323 private: 324 BoxedProcedureOptions options; 325 }; 326 } // namespace 327 328 std::unique_ptr<mlir::Pass> fir::createBoxedProcedurePass() { 329 return std::make_unique<BoxedProcedurePass>(); 330 } 331 332 std::unique_ptr<mlir::Pass> fir::createBoxedProcedurePass(bool useThunks) { 333 return std::make_unique<BoxedProcedurePass>(useThunks); 334 } 335