slang_backend.cpp revision c383a500aa59423264811be3874461bf8adbfea0
1/* 2 * Copyright 2010, The Android Open Source Project 3 * 4 * Licensed under the Apache License, Version 2.0 (the "License"); 5 * you may not use this file except in compliance with the License. 6 * You may obtain a copy of the License at 7 * 8 * http://www.apache.org/licenses/LICENSE-2.0 9 * 10 * Unless required by applicable law or agreed to in writing, software 11 * distributed under the License is distributed on an "AS IS" BASIS, 12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 13 * See the License for the specific language governing permissions and 14 * limitations under the License. 15 */ 16 17#include "slang_backend.h" 18 19#include "llvm/Module.h" 20#include "llvm/Metadata.h" 21#include "llvm/LLVMContext.h" 22 23#include "llvm/Target/TargetMachine.h" 24#include "llvm/Target/TargetOptions.h" 25#include "llvm/Target/TargetRegistry.h" 26#include "llvm/Target/SubtargetFeature.h" 27 28#include "llvm/CodeGen/RegAllocRegistry.h" 29#include "llvm/CodeGen/SchedulerRegistry.h" 30 31#include "llvm/Assembly/PrintModulePass.h" 32#include "llvm/Bitcode/ReaderWriter.h" 33 34#include "clang/AST/Decl.h" 35#include "clang/AST/DeclGroup.h" 36#include "clang/AST/ASTContext.h" 37 38#include "clang/Basic/TargetInfo.h" 39#include "clang/Basic/Diagnostic.h" 40#include "clang/Basic/TargetOptions.h" 41 42#include "clang/Frontend/CodeGenOptions.h" 43#include "clang/Frontend/FrontendDiagnostic.h" 44 45#include "clang/CodeGen/ModuleBuilder.h" 46 47#include "slang.h" 48 49using namespace slang; 50 51void Backend::CreateFunctionPasses() { 52 if (!mPerFunctionPasses) { 53 mPerFunctionPasses = new llvm::FunctionPassManager(mpModule); 54 mPerFunctionPasses->add(new llvm::TargetData(*mpTargetData)); 55 56 llvm::createStandardFunctionPasses(mPerFunctionPasses, 57 mCodeGenOpts.OptimizationLevel); 58 } 59 return; 60} 61 62void Backend::CreateModulePasses() { 63 if (!mPerModulePasses) { 64 mPerModulePasses = new llvm::PassManager(); 65 mPerModulePasses->add(new llvm::TargetData(*mpTargetData)); 66 67 llvm::createStandardModulePasses(mPerModulePasses, 68 mCodeGenOpts.OptimizationLevel, 69 mCodeGenOpts.OptimizeSize, 70 mCodeGenOpts.UnitAtATime, 71 mCodeGenOpts.UnrollLoops, 72 /* SimplifyLibCalls = */true, 73 /* HaveExceptions = */false, 74 /* InliningPass = */NULL); 75 } 76 return; 77} 78 79bool Backend::CreateCodeGenPasses() { 80 if ((mOT != Slang::OT_Assembly) && (mOT != Slang::OT_Object)) 81 return true; 82 83 // Now we add passes for code emitting 84 if (mCodeGenPasses) { 85 return true; 86 } else { 87 mCodeGenPasses = new llvm::FunctionPassManager(mpModule); 88 mCodeGenPasses->add(new llvm::TargetData(*mpTargetData)); 89 } 90 91 // Create the TargetMachine for generating code. 92 std::string Triple = mpModule->getTargetTriple(); 93 94 std::string Error; 95 const llvm::Target* TargetInfo = 96 llvm::TargetRegistry::lookupTarget(Triple, Error); 97 if (TargetInfo == NULL) { 98 mDiags.Report(clang::diag::err_fe_unable_to_create_target) << Error; 99 return false; 100 } 101 102 llvm::NoFramePointerElim = mCodeGenOpts.DisableFPElim; 103 104 // Use hardware FPU. 105 // 106 // FIXME: Need to detect the CPU capability and decide whether to use softfp. 107 // To use softfp, change following 2 lines to 108 // 109 // llvm::FloatABIType = llvm::FloatABI::Soft; 110 // llvm::UseSoftFloat = true; 111 llvm::FloatABIType = llvm::FloatABI::Hard; 112 llvm::UseSoftFloat = false; 113 114 // BCC needs all unknown symbols resolved at compilation time. So we don't 115 // need any relocation model. 116 llvm::TargetMachine::setRelocationModel(llvm::Reloc::Static); 117 118 119 // The target with pointer size greater than 32 (e.g. x86_64 architecture) may 120 // need large data address model 121 if (mpTargetData->getPointerSizeInBits() > 32) 122 llvm::TargetMachine::setCodeModel(llvm::CodeModel::Medium); 123 else 124 // This is set for the linker (specify how large of the virtual addresses we 125 // can access for all unknown symbols.) 126 127 llvm::TargetMachine::setCodeModel(llvm::CodeModel::Small); 128 129 // Setup feature string 130 std::string FeaturesStr; 131 if (mTargetOpts.CPU.size() || mTargetOpts.Features.size()) { 132 llvm::SubtargetFeatures Features; 133 134 Features.setCPU(mTargetOpts.CPU); 135 136 for (std::vector<std::string>::const_iterator 137 I = mTargetOpts.Features.begin(), E = mTargetOpts.Features.end(); 138 I != E; 139 I++) 140 Features.AddFeature(*I); 141 142 FeaturesStr = Features.getString(); 143 } 144 llvm::TargetMachine *TM = 145 TargetInfo->createTargetMachine(Triple, FeaturesStr); 146 147 // Register scheduler 148 llvm::RegisterScheduler::setDefault(llvm::createDefaultScheduler); 149 150 // Register allocation policy: 151 // createFastRegisterAllocator: fast but bad quality 152 // createLinearScanRegisterAllocator: not so fast but good quality 153 llvm::RegisterRegAlloc::setDefault((mCodeGenOpts.OptimizationLevel == 0) ? 154 llvm::createFastRegisterAllocator : 155 llvm::createLinearScanRegisterAllocator); 156 157 llvm::CodeGenOpt::Level OptLevel = llvm::CodeGenOpt::Default; 158 if (mCodeGenOpts.OptimizationLevel == 0) 159 OptLevel = llvm::CodeGenOpt::None; 160 else if (mCodeGenOpts.OptimizationLevel == 3) 161 OptLevel = llvm::CodeGenOpt::Aggressive; 162 163 llvm::TargetMachine::CodeGenFileType CGFT = 164 llvm::TargetMachine::CGFT_AssemblyFile; 165 if (mOT == Slang::OT_Object) 166 CGFT = llvm::TargetMachine::CGFT_ObjectFile; 167 if (TM->addPassesToEmitFile(*mCodeGenPasses, FormattedOutStream, 168 CGFT, OptLevel)) { 169 mDiags.Report(clang::diag::err_fe_unable_to_interface_with_target); 170 return false; 171 } 172 173 return true; 174} 175 176Backend::Backend(clang::Diagnostic &Diags, 177 const clang::CodeGenOptions &CodeGenOpts, 178 const clang::TargetOptions &TargetOpts, 179 const PragmaList &Pragmas, 180 llvm::raw_ostream *OS, 181 Slang::OutputType OT) 182 : ASTConsumer(), 183 mCodeGenOpts(CodeGenOpts), 184 mTargetOpts(TargetOpts), 185 mpOS(OS), 186 mOT(OT), 187 mpTargetData(NULL), 188 mGen(NULL), 189 mPerFunctionPasses(NULL), 190 mPerModulePasses(NULL), 191 mCodeGenPasses(NULL), 192 mLLVMContext(llvm::getGlobalContext()), 193 mDiags(Diags), 194 mpModule(NULL), 195 mPragmas(Pragmas) { 196 FormattedOutStream.setStream(*mpOS, 197 llvm::formatted_raw_ostream::PRESERVE_STREAM); 198 mGen = CreateLLVMCodeGen(mDiags, "", mCodeGenOpts, mLLVMContext); 199 return; 200} 201 202void Backend::Initialize(clang::ASTContext &Ctx) { 203 mGen->Initialize(Ctx); 204 205 mpModule = mGen->GetModule(); 206 mpTargetData = new llvm::TargetData(Slang::TargetDescription); 207 208 return; 209} 210 211void Backend::HandleTopLevelDecl(clang::DeclGroupRef D) { 212 mGen->HandleTopLevelDecl(D); 213 return; 214} 215 216void Backend::HandleTranslationUnit(clang::ASTContext &Ctx) { 217 mGen->HandleTranslationUnit(Ctx); 218 219 // Here, we complete a translation unit (whole translation unit is now in LLVM 220 // IR). Now, interact with LLVM backend to generate actual machine code (asm 221 // or machine code, whatever.) 222 223 // Silently ignore if we weren't initialized for some reason. 224 if (!mpModule || !mpTargetData) 225 return; 226 227 llvm::Module *M = mGen->ReleaseModule(); 228 if (!M) { 229 // The module has been released by IR gen on failures, do not double free. 230 mpModule = NULL; 231 return; 232 } 233 234 assert(mpModule == M && "Unexpected module change during LLVM IR generation"); 235 236 // Insert #pragma information into metadata section of module 237 if (!mPragmas.empty()) { 238 llvm::NamedMDNode *PragmaMetadata = 239 mpModule->getOrInsertNamedMetadata(Slang::PragmaMetadataName); 240 for (PragmaList::const_iterator I = mPragmas.begin(), E = mPragmas.end(); 241 I != E; 242 I++) { 243 llvm::SmallVector<llvm::Value*, 2> Pragma; 244 // Name goes first 245 Pragma.push_back(llvm::MDString::get(mLLVMContext, I->first)); 246 // And then value 247 Pragma.push_back(llvm::MDString::get(mLLVMContext, I->second)); 248 // Create MDNode and insert into PragmaMetadata 249 PragmaMetadata->addOperand( 250 llvm::MDNode::get(mLLVMContext, Pragma.data(), Pragma.size())); 251 } 252 } 253 254 HandleTranslationUnitEx(Ctx); 255 256 // Create passes for optimization and code emission 257 258 // Create and run per-function passes 259 CreateFunctionPasses(); 260 if (mPerFunctionPasses) { 261 mPerFunctionPasses->doInitialization(); 262 263 for (llvm::Module::iterator I = mpModule->begin(), E = mpModule->end(); 264 I != E; 265 I++) 266 if (!I->isDeclaration()) 267 mPerFunctionPasses->run(*I); 268 269 mPerFunctionPasses->doFinalization(); 270 } 271 272 // Create and run module passes 273 CreateModulePasses(); 274 if (mPerModulePasses) 275 mPerModulePasses->run(*mpModule); 276 277 switch (mOT) { 278 case Slang::OT_Assembly: 279 case Slang::OT_Object: { 280 if (!CreateCodeGenPasses()) 281 return; 282 283 mCodeGenPasses->doInitialization(); 284 285 for (llvm::Module::iterator I = mpModule->begin(), E = mpModule->end(); 286 I != E; 287 I++) 288 if (!I->isDeclaration()) 289 mCodeGenPasses->run(*I); 290 291 mCodeGenPasses->doFinalization(); 292 break; 293 } 294 case Slang::OT_LLVMAssembly: { 295 llvm::PassManager *LLEmitPM = new llvm::PassManager(); 296 LLEmitPM->add(llvm::createPrintModulePass(&FormattedOutStream)); 297 LLEmitPM->run(*mpModule); 298 break; 299 } 300 case Slang::OT_Bitcode: { 301 llvm::PassManager *BCEmitPM = new llvm::PassManager(); 302 BCEmitPM->add(llvm::createBitcodeWriterPass(FormattedOutStream)); 303 BCEmitPM->run(*mpModule); 304 break; 305 } 306 case Slang::OT_Nothing: { 307 return; 308 } 309 default: { 310 assert(false && "Unknown output type"); 311 } 312 } 313 314 FormattedOutStream.flush(); 315 316 return; 317} 318 319void Backend::HandleTagDeclDefinition(clang::TagDecl *D) { 320 mGen->HandleTagDeclDefinition(D); 321 return; 322} 323 324void Backend::CompleteTentativeDefinition(clang::VarDecl *D) { 325 mGen->CompleteTentativeDefinition(D); 326 return; 327} 328 329Backend::~Backend() { 330 delete mpModule; 331 delete mpTargetData; 332 delete mGen; 333 delete mPerFunctionPasses; 334 delete mPerModulePasses; 335 delete mCodeGenPasses; 336 return; 337} 338