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 "flang/Optimizer/CodeGen/CodeGen.h" 10 11 #include "flang/Optimizer/Builder/FIRBuilder.h" 12 #include "flang/Optimizer/Builder/LowLevelIntrinsics.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/Dialect/Support/FIRContext.h" 17 #include "flang/Optimizer/Support/FatalError.h" 18 #include "flang/Optimizer/Support/InternalNames.h" 19 #include "mlir/IR/PatternMatch.h" 20 #include "mlir/Pass/Pass.h" 21 #include "mlir/Transforms/DialectConversion.h" 22 #include "llvm/ADT/DenseMap.h" 23 24 namespace fir { 25 #define GEN_PASS_DEF_BOXEDPROCEDUREPASS 26 #include "flang/Optimizer/CodeGen/CGPasses.h.inc" 27 } // namespace fir 28 29 #define DEBUG_TYPE "flang-procedure-pointer" 30 31 using namespace fir; 32 33 namespace { 34 /// Options to the procedure pointer pass. 35 struct BoxedProcedureOptions { 36 // Lower the boxproc abstraction to function pointers and thunks where 37 // required. 38 bool useThunks = true; 39 }; 40 41 /// This type converter rewrites all `!fir.boxproc<Func>` types to `Func` types. 42 class BoxprocTypeRewriter : public mlir::TypeConverter { 43 public: 44 using mlir::TypeConverter::convertType; 45 46 /// Does the type \p ty need to be converted? 47 /// Any type that is a `!fir.boxproc` in whole or in part will need to be 48 /// converted to a function type to lower the IR to function pointer form in 49 /// the default implementation performed in this pass. Other implementations 50 /// are possible, so those may convert `!fir.boxproc` to some other type or 51 /// not at all depending on the implementation target's characteristics and 52 /// preference. 53 bool needsConversion(mlir::Type ty) { 54 if (mlir::isa<BoxProcType>(ty)) 55 return true; 56 if (auto funcTy = mlir::dyn_cast<mlir::FunctionType>(ty)) { 57 for (auto t : funcTy.getInputs()) 58 if (needsConversion(t)) 59 return true; 60 for (auto t : funcTy.getResults()) 61 if (needsConversion(t)) 62 return true; 63 return false; 64 } 65 if (auto tupleTy = mlir::dyn_cast<mlir::TupleType>(ty)) { 66 for (auto t : tupleTy.getTypes()) 67 if (needsConversion(t)) 68 return true; 69 return false; 70 } 71 if (auto recTy = mlir::dyn_cast<RecordType>(ty)) { 72 auto visited = visitedTypes.find(ty); 73 if (visited != visitedTypes.end()) 74 return visited->second; 75 [[maybe_unused]] auto newIt = visitedTypes.try_emplace(ty, false); 76 assert(newIt.second && "expected ty to not be in the map"); 77 bool wasAlreadyVisitingRecordType = needConversionIsVisitingRecordType; 78 needConversionIsVisitingRecordType = true; 79 bool result = false; 80 for (auto t : recTy.getTypeList()) { 81 if (needsConversion(t.second)) { 82 result = true; 83 break; 84 } 85 } 86 // Only keep the result cached if the fir.type visited was a "top-level 87 // type". Nested types with a recursive reference to the "top-level type" 88 // may incorrectly have been resolved as not needed conversions because it 89 // had not been determined yet if the "top-level type" needed conversion. 90 // This is not an issue to determine the "top-level type" need of 91 // conversion, but the result should not be kept and later used in other 92 // contexts. 93 needConversionIsVisitingRecordType = wasAlreadyVisitingRecordType; 94 if (needConversionIsVisitingRecordType) 95 visitedTypes.erase(ty); 96 else 97 visitedTypes.find(ty)->second = result; 98 return result; 99 } 100 if (auto boxTy = mlir::dyn_cast<BaseBoxType>(ty)) 101 return needsConversion(boxTy.getEleTy()); 102 if (isa_ref_type(ty)) 103 return needsConversion(unwrapRefType(ty)); 104 if (auto t = mlir::dyn_cast<SequenceType>(ty)) 105 return needsConversion(unwrapSequenceType(ty)); 106 if (auto t = mlir::dyn_cast<TypeDescType>(ty)) 107 return needsConversion(t.getOfTy()); 108 return false; 109 } 110 111 BoxprocTypeRewriter(mlir::Location location) : loc{location} { 112 addConversion([](mlir::Type ty) { return ty; }); 113 addConversion( 114 [&](BoxProcType boxproc) { return convertType(boxproc.getEleTy()); }); 115 addConversion([&](mlir::TupleType tupTy) { 116 llvm::SmallVector<mlir::Type> memTys; 117 for (auto ty : tupTy.getTypes()) 118 memTys.push_back(convertType(ty)); 119 return mlir::TupleType::get(tupTy.getContext(), memTys); 120 }); 121 addConversion([&](mlir::FunctionType funcTy) { 122 llvm::SmallVector<mlir::Type> inTys; 123 llvm::SmallVector<mlir::Type> resTys; 124 for (auto ty : funcTy.getInputs()) 125 inTys.push_back(convertType(ty)); 126 for (auto ty : funcTy.getResults()) 127 resTys.push_back(convertType(ty)); 128 return mlir::FunctionType::get(funcTy.getContext(), inTys, resTys); 129 }); 130 addConversion([&](ReferenceType ty) { 131 return ReferenceType::get(convertType(ty.getEleTy())); 132 }); 133 addConversion([&](PointerType ty) { 134 return PointerType::get(convertType(ty.getEleTy())); 135 }); 136 addConversion( 137 [&](HeapType ty) { return HeapType::get(convertType(ty.getEleTy())); }); 138 addConversion([&](fir::LLVMPointerType ty) { 139 return fir::LLVMPointerType::get(convertType(ty.getEleTy())); 140 }); 141 addConversion( 142 [&](BoxType ty) { return BoxType::get(convertType(ty.getEleTy())); }); 143 addConversion([&](ClassType ty) { 144 return ClassType::get(convertType(ty.getEleTy())); 145 }); 146 addConversion([&](SequenceType ty) { 147 // TODO: add ty.getLayoutMap() as needed. 148 return SequenceType::get(ty.getShape(), convertType(ty.getEleTy())); 149 }); 150 addConversion([&](RecordType ty) -> mlir::Type { 151 if (!needsConversion(ty)) 152 return ty; 153 if (auto converted = convertedTypes.lookup(ty)) 154 return converted; 155 auto rec = RecordType::get(ty.getContext(), 156 ty.getName().str() + boxprocSuffix.str()); 157 if (rec.isFinalized()) 158 return rec; 159 [[maybe_unused]] auto it = convertedTypes.try_emplace(ty, rec); 160 assert(it.second && "expected ty to not be in the map"); 161 std::vector<RecordType::TypePair> ps = ty.getLenParamList(); 162 std::vector<RecordType::TypePair> cs; 163 for (auto t : ty.getTypeList()) { 164 if (needsConversion(t.second)) 165 cs.emplace_back(t.first, convertType(t.second)); 166 else 167 cs.emplace_back(t.first, t.second); 168 } 169 rec.finalize(ps, cs); 170 rec.pack(ty.isPacked()); 171 return rec; 172 }); 173 addConversion([&](TypeDescType ty) { 174 return TypeDescType::get(convertType(ty.getOfTy())); 175 }); 176 addSourceMaterialization(materializeProcedure); 177 addTargetMaterialization(materializeProcedure); 178 } 179 180 static mlir::Value materializeProcedure(mlir::OpBuilder &builder, 181 BoxProcType type, 182 mlir::ValueRange inputs, 183 mlir::Location loc) { 184 assert(inputs.size() == 1); 185 return builder.create<ConvertOp>(loc, unwrapRefType(type.getEleTy()), 186 inputs[0]); 187 } 188 189 void setLocation(mlir::Location location) { loc = location; } 190 191 private: 192 // Maps to deal with recursive derived types (avoid infinite loops). 193 // Caching is also beneficial for apps with big types (dozens of 194 // components and or parent types), so the lifetime of the cache 195 // is the whole pass. 196 llvm::DenseMap<mlir::Type, bool> visitedTypes; 197 bool needConversionIsVisitingRecordType = false; 198 llvm::DenseMap<mlir::Type, mlir::Type> convertedTypes; 199 mlir::Location loc; 200 }; 201 202 /// A `boxproc` is an abstraction for a Fortran procedure reference. Typically, 203 /// Fortran procedures can be referenced directly through a function pointer. 204 /// However, Fortran has one-level dynamic scoping between a host procedure and 205 /// its internal procedures. This allows internal procedures to directly access 206 /// and modify the state of the host procedure's variables. 207 /// 208 /// There are any number of possible implementations possible. 209 /// 210 /// The implementation used here is to convert `boxproc` values to function 211 /// pointers everywhere. If a `boxproc` value includes a frame pointer to the 212 /// host procedure's data, then a thunk will be created at runtime to capture 213 /// the frame pointer during execution. In LLVM IR, the frame pointer is 214 /// designated with the `nest` attribute. The thunk's address will then be used 215 /// as the call target instead of the original function's address directly. 216 class BoxedProcedurePass 217 : public fir::impl::BoxedProcedurePassBase<BoxedProcedurePass> { 218 public: 219 using BoxedProcedurePassBase<BoxedProcedurePass>::BoxedProcedurePassBase; 220 221 inline mlir::ModuleOp getModule() { return getOperation(); } 222 223 void runOnOperation() override final { 224 if (options.useThunks) { 225 auto *context = &getContext(); 226 mlir::IRRewriter rewriter(context); 227 BoxprocTypeRewriter typeConverter(mlir::UnknownLoc::get(context)); 228 getModule().walk([&](mlir::Operation *op) { 229 bool opIsValid = true; 230 typeConverter.setLocation(op->getLoc()); 231 if (auto addr = mlir::dyn_cast<BoxAddrOp>(op)) { 232 mlir::Type ty = addr.getVal().getType(); 233 mlir::Type resTy = addr.getResult().getType(); 234 if (llvm::isa<mlir::FunctionType>(ty) || 235 llvm::isa<fir::BoxProcType>(ty)) { 236 // Rewrite all `fir.box_addr` ops on values of type `!fir.boxproc` 237 // or function type to be `fir.convert` ops. 238 rewriter.setInsertionPoint(addr); 239 rewriter.replaceOpWithNewOp<ConvertOp>( 240 addr, typeConverter.convertType(addr.getType()), addr.getVal()); 241 opIsValid = false; 242 } else if (typeConverter.needsConversion(resTy)) { 243 rewriter.startOpModification(op); 244 op->getResult(0).setType(typeConverter.convertType(resTy)); 245 rewriter.finalizeOpModification(op); 246 } 247 } else if (auto func = mlir::dyn_cast<mlir::func::FuncOp>(op)) { 248 mlir::FunctionType ty = func.getFunctionType(); 249 if (typeConverter.needsConversion(ty)) { 250 rewriter.startOpModification(func); 251 auto toTy = 252 mlir::cast<mlir::FunctionType>(typeConverter.convertType(ty)); 253 if (!func.empty()) 254 for (auto e : llvm::enumerate(toTy.getInputs())) { 255 unsigned i = e.index(); 256 auto &block = func.front(); 257 block.insertArgument(i, e.value(), func.getLoc()); 258 block.getArgument(i + 1).replaceAllUsesWith( 259 block.getArgument(i)); 260 block.eraseArgument(i + 1); 261 } 262 func.setType(toTy); 263 rewriter.finalizeOpModification(func); 264 } 265 } else if (auto embox = mlir::dyn_cast<EmboxProcOp>(op)) { 266 // Rewrite all `fir.emboxproc` ops to either `fir.convert` or a thunk 267 // as required. 268 mlir::Type toTy = typeConverter.convertType( 269 mlir::cast<BoxProcType>(embox.getType()).getEleTy()); 270 rewriter.setInsertionPoint(embox); 271 if (embox.getHost()) { 272 // Create the thunk. 273 auto module = embox->getParentOfType<mlir::ModuleOp>(); 274 FirOpBuilder builder(rewriter, module); 275 auto loc = embox.getLoc(); 276 mlir::Type i8Ty = builder.getI8Type(); 277 mlir::Type i8Ptr = builder.getRefType(i8Ty); 278 mlir::Type buffTy = SequenceType::get({32}, i8Ty); 279 auto buffer = builder.create<AllocaOp>(loc, buffTy); 280 mlir::Value closure = 281 builder.createConvert(loc, i8Ptr, embox.getHost()); 282 mlir::Value tramp = builder.createConvert(loc, i8Ptr, buffer); 283 mlir::Value func = 284 builder.createConvert(loc, i8Ptr, embox.getFunc()); 285 builder.create<fir::CallOp>( 286 loc, factory::getLlvmInitTrampoline(builder), 287 llvm::ArrayRef<mlir::Value>{tramp, func, closure}); 288 auto adjustCall = builder.create<fir::CallOp>( 289 loc, factory::getLlvmAdjustTrampoline(builder), 290 llvm::ArrayRef<mlir::Value>{tramp}); 291 rewriter.replaceOpWithNewOp<ConvertOp>(embox, toTy, 292 adjustCall.getResult(0)); 293 opIsValid = false; 294 } else { 295 // Just forward the function as a pointer. 296 rewriter.replaceOpWithNewOp<ConvertOp>(embox, toTy, 297 embox.getFunc()); 298 opIsValid = false; 299 } 300 } else if (auto global = mlir::dyn_cast<GlobalOp>(op)) { 301 auto ty = global.getType(); 302 if (typeConverter.needsConversion(ty)) { 303 rewriter.startOpModification(global); 304 auto toTy = typeConverter.convertType(ty); 305 global.setType(toTy); 306 rewriter.finalizeOpModification(global); 307 } 308 } else if (auto mem = mlir::dyn_cast<AllocaOp>(op)) { 309 auto ty = mem.getType(); 310 if (typeConverter.needsConversion(ty)) { 311 rewriter.setInsertionPoint(mem); 312 auto toTy = typeConverter.convertType(unwrapRefType(ty)); 313 bool isPinned = mem.getPinned(); 314 llvm::StringRef uniqName = 315 mem.getUniqName().value_or(llvm::StringRef()); 316 llvm::StringRef bindcName = 317 mem.getBindcName().value_or(llvm::StringRef()); 318 rewriter.replaceOpWithNewOp<AllocaOp>( 319 mem, toTy, uniqName, bindcName, isPinned, mem.getTypeparams(), 320 mem.getShape()); 321 opIsValid = false; 322 } 323 } else if (auto mem = mlir::dyn_cast<AllocMemOp>(op)) { 324 auto ty = mem.getType(); 325 if (typeConverter.needsConversion(ty)) { 326 rewriter.setInsertionPoint(mem); 327 auto toTy = typeConverter.convertType(unwrapRefType(ty)); 328 llvm::StringRef uniqName = 329 mem.getUniqName().value_or(llvm::StringRef()); 330 llvm::StringRef bindcName = 331 mem.getBindcName().value_or(llvm::StringRef()); 332 rewriter.replaceOpWithNewOp<AllocMemOp>( 333 mem, toTy, uniqName, bindcName, mem.getTypeparams(), 334 mem.getShape()); 335 opIsValid = false; 336 } 337 } else if (auto coor = mlir::dyn_cast<CoordinateOp>(op)) { 338 auto ty = coor.getType(); 339 mlir::Type baseTy = coor.getBaseType(); 340 if (typeConverter.needsConversion(ty) || 341 typeConverter.needsConversion(baseTy)) { 342 rewriter.setInsertionPoint(coor); 343 auto toTy = typeConverter.convertType(ty); 344 auto toBaseTy = typeConverter.convertType(baseTy); 345 rewriter.replaceOpWithNewOp<CoordinateOp>(coor, toTy, coor.getRef(), 346 coor.getCoor(), toBaseTy); 347 opIsValid = false; 348 } 349 } else if (auto index = mlir::dyn_cast<FieldIndexOp>(op)) { 350 auto ty = index.getType(); 351 mlir::Type onTy = index.getOnType(); 352 if (typeConverter.needsConversion(ty) || 353 typeConverter.needsConversion(onTy)) { 354 rewriter.setInsertionPoint(index); 355 auto toTy = typeConverter.convertType(ty); 356 auto toOnTy = typeConverter.convertType(onTy); 357 rewriter.replaceOpWithNewOp<FieldIndexOp>( 358 index, toTy, index.getFieldId(), toOnTy, index.getTypeparams()); 359 opIsValid = false; 360 } 361 } else if (auto index = mlir::dyn_cast<LenParamIndexOp>(op)) { 362 auto ty = index.getType(); 363 mlir::Type onTy = index.getOnType(); 364 if (typeConverter.needsConversion(ty) || 365 typeConverter.needsConversion(onTy)) { 366 rewriter.setInsertionPoint(index); 367 auto toTy = typeConverter.convertType(ty); 368 auto toOnTy = typeConverter.convertType(onTy); 369 rewriter.replaceOpWithNewOp<LenParamIndexOp>( 370 index, toTy, index.getFieldId(), toOnTy, index.getTypeparams()); 371 opIsValid = false; 372 } 373 } else { 374 rewriter.startOpModification(op); 375 // Convert the operands if needed 376 for (auto i : llvm::enumerate(op->getResultTypes())) 377 if (typeConverter.needsConversion(i.value())) { 378 auto toTy = typeConverter.convertType(i.value()); 379 op->getResult(i.index()).setType(toTy); 380 } 381 382 // Convert the type attributes if needed 383 for (const mlir::NamedAttribute &attr : op->getAttrDictionary()) 384 if (auto tyAttr = llvm::dyn_cast<mlir::TypeAttr>(attr.getValue())) 385 if (typeConverter.needsConversion(tyAttr.getValue())) { 386 auto toTy = typeConverter.convertType(tyAttr.getValue()); 387 op->setAttr(attr.getName(), mlir::TypeAttr::get(toTy)); 388 } 389 rewriter.finalizeOpModification(op); 390 } 391 // Ensure block arguments are updated if needed. 392 if (opIsValid && op->getNumRegions() != 0) { 393 rewriter.startOpModification(op); 394 for (mlir::Region ®ion : op->getRegions()) 395 for (mlir::Block &block : region.getBlocks()) 396 for (mlir::BlockArgument blockArg : block.getArguments()) 397 if (typeConverter.needsConversion(blockArg.getType())) { 398 mlir::Type toTy = 399 typeConverter.convertType(blockArg.getType()); 400 blockArg.setType(toTy); 401 } 402 rewriter.finalizeOpModification(op); 403 } 404 }); 405 } 406 } 407 408 private: 409 BoxedProcedureOptions options; 410 }; 411 } // namespace 412