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 bool result = false; 66 visitedTypes.push_back(recTy); 67 for (auto t : recTy.getTypeList()) { 68 if (llvm::any_of(visitedTypes, 69 [&](mlir::Type rt) { return rt == recTy; })) 70 continue; 71 if (needsConversion(t.second)) { 72 result = true; 73 break; 74 } 75 } 76 visitedTypes.pop_back(); 77 return result; 78 } 79 if (auto boxTy = ty.dyn_cast<BoxType>()) 80 return needsConversion(boxTy.getEleTy()); 81 if (isa_ref_type(ty)) 82 return needsConversion(unwrapRefType(ty)); 83 if (auto t = ty.dyn_cast<SequenceType>()) 84 return needsConversion(unwrapSequenceType(ty)); 85 return false; 86 } 87 88 BoxprocTypeRewriter() { 89 addConversion([](mlir::Type ty) { return ty; }); 90 addConversion([](BoxProcType boxproc) { return 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) { 121 // FIR record types can have recursive references, so conversion is a bit 122 // more complex than the other types. This conversion is not needed 123 // presently, so just emit a TODO message. Need to consider the uniqued 124 // name of the record, etc. 125 fir::emitFatalError( 126 mlir::UnknownLoc::get(ty.getContext()), 127 "not yet implemented: record type with a boxproc type"); 128 return RecordType::get(ty.getContext(), "*fixme*"); 129 }); 130 addArgumentMaterialization(materializeProcedure); 131 addSourceMaterialization(materializeProcedure); 132 addTargetMaterialization(materializeProcedure); 133 } 134 135 static mlir::Value materializeProcedure(mlir::OpBuilder &builder, 136 BoxProcType type, 137 mlir::ValueRange inputs, 138 mlir::Location loc) { 139 assert(inputs.size() == 1); 140 return builder.create<ConvertOp>(loc, unwrapRefType(type.getEleTy()), 141 inputs[0]); 142 } 143 144 private: 145 llvm::SmallVector<mlir::Type> visitedTypes; 146 }; 147 148 /// A `boxproc` is an abstraction for a Fortran procedure reference. Typically, 149 /// Fortran procedures can be referenced directly through a function pointer. 150 /// However, Fortran has one-level dynamic scoping between a host procedure and 151 /// its internal procedures. This allows internal procedures to directly access 152 /// and modify the state of the host procedure's variables. 153 /// 154 /// There are any number of possible implementations possible. 155 /// 156 /// The implementation used here is to convert `boxproc` values to function 157 /// pointers everywhere. If a `boxproc` value includes a frame pointer to the 158 /// host procedure's data, then a thunk will be created at runtime to capture 159 /// the frame pointer during execution. In LLVM IR, the frame pointer is 160 /// designated with the `nest` attribute. The thunk's address will then be used 161 /// as the call target instead of the original function's address directly. 162 class BoxedProcedurePass : public BoxedProcedurePassBase<BoxedProcedurePass> { 163 public: 164 BoxedProcedurePass() { options = {true}; } 165 BoxedProcedurePass(bool useThunks) { options = {useThunks}; } 166 167 inline mlir::ModuleOp getModule() { return getOperation(); } 168 169 void runOnOperation() override final { 170 if (options.useThunks) { 171 auto *context = &getContext(); 172 mlir::IRRewriter rewriter(context); 173 BoxprocTypeRewriter typeConverter; 174 mlir::Dialect *firDialect = context->getLoadedDialect("fir"); 175 getModule().walk([&](mlir::Operation *op) { 176 if (auto addr = mlir::dyn_cast<BoxAddrOp>(op)) { 177 auto ty = addr.getVal().getType(); 178 if (typeConverter.needsConversion(ty) || 179 ty.isa<mlir::FunctionType>()) { 180 // Rewrite all `fir.box_addr` ops on values of type `!fir.boxproc` 181 // or function type to be `fir.convert` ops. 182 rewriter.setInsertionPoint(addr); 183 rewriter.replaceOpWithNewOp<ConvertOp>( 184 addr, typeConverter.convertType(addr.getType()), addr.getVal()); 185 } 186 } else if (auto func = mlir::dyn_cast<mlir::FuncOp>(op)) { 187 mlir::FunctionType ty = func.getFunctionType(); 188 if (typeConverter.needsConversion(ty)) { 189 rewriter.startRootUpdate(func); 190 auto toTy = 191 typeConverter.convertType(ty).cast<mlir::FunctionType>(); 192 if (!func.empty()) 193 for (auto e : llvm::enumerate(toTy.getInputs())) { 194 unsigned i = e.index(); 195 auto &block = func.front(); 196 block.insertArgument(i, e.value(), func.getLoc()); 197 block.getArgument(i + 1).replaceAllUsesWith( 198 block.getArgument(i)); 199 block.eraseArgument(i + 1); 200 } 201 func.setType(toTy); 202 rewriter.finalizeRootUpdate(func); 203 } 204 } else if (auto embox = mlir::dyn_cast<EmboxProcOp>(op)) { 205 // Rewrite all `fir.emboxproc` ops to either `fir.convert` or a thunk 206 // as required. 207 mlir::Type toTy = embox.getType().cast<BoxProcType>().getEleTy(); 208 rewriter.setInsertionPoint(embox); 209 if (embox.getHost()) { 210 // Create the thunk. 211 auto module = embox->getParentOfType<mlir::ModuleOp>(); 212 FirOpBuilder builder(rewriter, getKindMapping(module)); 213 auto loc = embox.getLoc(); 214 mlir::Type i8Ty = builder.getI8Type(); 215 mlir::Type i8Ptr = builder.getRefType(i8Ty); 216 mlir::Type buffTy = SequenceType::get({32}, i8Ty); 217 auto buffer = builder.create<AllocaOp>(loc, buffTy); 218 mlir::Value closure = 219 builder.createConvert(loc, i8Ptr, embox.getHost()); 220 mlir::Value tramp = builder.createConvert(loc, i8Ptr, buffer); 221 mlir::Value func = 222 builder.createConvert(loc, i8Ptr, embox.getFunc()); 223 builder.create<fir::CallOp>( 224 loc, factory::getLlvmInitTrampoline(builder), 225 llvm::ArrayRef<mlir::Value>{tramp, func, closure}); 226 auto adjustCall = builder.create<fir::CallOp>( 227 loc, factory::getLlvmAdjustTrampoline(builder), 228 llvm::ArrayRef<mlir::Value>{tramp}); 229 rewriter.replaceOpWithNewOp<ConvertOp>(embox, toTy, 230 adjustCall.getResult(0)); 231 } else { 232 // Just forward the function as a pointer. 233 rewriter.replaceOpWithNewOp<ConvertOp>(embox, toTy, 234 embox.getFunc()); 235 } 236 } else if (auto mem = mlir::dyn_cast<AllocaOp>(op)) { 237 auto ty = mem.getType(); 238 if (typeConverter.needsConversion(ty)) { 239 rewriter.setInsertionPoint(mem); 240 auto toTy = typeConverter.convertType(unwrapRefType(ty)); 241 bool isPinned = mem.getPinned(); 242 llvm::StringRef uniqName; 243 if (mem.getUniqName().hasValue()) 244 uniqName = mem.getUniqName().getValue(); 245 llvm::StringRef bindcName; 246 if (mem.getBindcName().hasValue()) 247 bindcName = mem.getBindcName().getValue(); 248 rewriter.replaceOpWithNewOp<AllocaOp>( 249 mem, toTy, uniqName, bindcName, isPinned, mem.getTypeparams(), 250 mem.getShape()); 251 } 252 } else if (auto mem = mlir::dyn_cast<AllocMemOp>(op)) { 253 auto ty = mem.getType(); 254 if (typeConverter.needsConversion(ty)) { 255 rewriter.setInsertionPoint(mem); 256 auto toTy = typeConverter.convertType(unwrapRefType(ty)); 257 llvm::StringRef uniqName; 258 if (mem.getUniqName().hasValue()) 259 uniqName = mem.getUniqName().getValue(); 260 llvm::StringRef bindcName; 261 if (mem.getBindcName().hasValue()) 262 bindcName = mem.getBindcName().getValue(); 263 rewriter.replaceOpWithNewOp<AllocMemOp>( 264 mem, toTy, uniqName, bindcName, mem.getTypeparams(), 265 mem.getShape()); 266 } 267 } else if (auto coor = mlir::dyn_cast<CoordinateOp>(op)) { 268 auto ty = coor.getType(); 269 mlir::Type baseTy = coor.getBaseType(); 270 if (typeConverter.needsConversion(ty) || 271 typeConverter.needsConversion(baseTy)) { 272 rewriter.setInsertionPoint(coor); 273 auto toTy = typeConverter.convertType(ty); 274 auto toBaseTy = typeConverter.convertType(baseTy); 275 rewriter.replaceOpWithNewOp<CoordinateOp>(coor, toTy, coor.getRef(), 276 coor.getCoor(), toBaseTy); 277 } 278 } else if (auto index = mlir::dyn_cast<FieldIndexOp>(op)) { 279 auto ty = index.getType(); 280 mlir::Type onTy = index.getOnType(); 281 if (typeConverter.needsConversion(ty) || 282 typeConverter.needsConversion(onTy)) { 283 rewriter.setInsertionPoint(index); 284 auto toTy = typeConverter.convertType(ty); 285 auto toOnTy = typeConverter.convertType(onTy); 286 rewriter.replaceOpWithNewOp<FieldIndexOp>( 287 index, toTy, index.getFieldId(), toOnTy, index.getTypeparams()); 288 } 289 } else if (auto index = mlir::dyn_cast<LenParamIndexOp>(op)) { 290 auto ty = index.getType(); 291 mlir::Type onTy = index.getOnType(); 292 if (typeConverter.needsConversion(ty) || 293 typeConverter.needsConversion(onTy)) { 294 rewriter.setInsertionPoint(index); 295 auto toTy = typeConverter.convertType(ty); 296 auto toOnTy = typeConverter.convertType(onTy); 297 rewriter.replaceOpWithNewOp<LenParamIndexOp>( 298 mem, toTy, index.getFieldId(), toOnTy); 299 } 300 } else if (op->getDialect() == firDialect) { 301 rewriter.startRootUpdate(op); 302 for (auto i : llvm::enumerate(op->getResultTypes())) 303 if (typeConverter.needsConversion(i.value())) { 304 auto toTy = typeConverter.convertType(i.value()); 305 op->getResult(i.index()).setType(toTy); 306 } 307 rewriter.finalizeRootUpdate(op); 308 } 309 }); 310 } 311 // TODO: any alternative implementation. Note: currently, the default code 312 // gen will not be able to handle boxproc and will give an error. 313 } 314 315 private: 316 BoxedProcedureOptions options; 317 }; 318 } // namespace 319 320 std::unique_ptr<mlir::Pass> fir::createBoxedProcedurePass() { 321 return std::make_unique<BoxedProcedurePass>(); 322 } 323 324 std::unique_ptr<mlir::Pass> fir::createBoxedProcedurePass(bool useThunks) { 325 return std::make_unique<BoxedProcedurePass>(useThunks); 326 } 327