slang_backend.cpp revision 3a9ca1f0d6bd8f12c2bb2adea51f95c255996180
1#include "slang_backend.h" 2 3#include "llvm/Module.h" 4#include "llvm/Metadata.h" 5#include "llvm/LLVMContext.h" 6 7#include "llvm/Target/TargetMachine.h" 8#include "llvm/Target/TargetOptions.h" 9#include "llvm/Target/TargetRegistry.h" 10#include "llvm/Target/SubtargetFeature.h" 11 12#include "llvm/CodeGen/RegAllocRegistry.h" 13#include "llvm/CodeGen/SchedulerRegistry.h" 14 15#include "llvm/Assembly/PrintModulePass.h" 16#include "llvm/Bitcode/ReaderWriter.h" 17 18#include "clang/AST/Decl.h" 19#include "clang/AST/DeclGroup.h" 20#include "clang/AST/ASTContext.h" 21 22#include "clang/Basic/TargetInfo.h" 23#include "clang/Basic/Diagnostic.h" 24#include "clang/Basic/TargetOptions.h" 25 26#include "clang/Frontend/CodeGenOptions.h" 27#include "clang/Frontend/FrontendDiagnostic.h" 28 29#include "clang/CodeGen/ModuleBuilder.h" 30 31#include "slang.h" 32 33using namespace slang; 34 35void Backend::CreateFunctionPasses() { 36 if (!mPerFunctionPasses) { 37 mPerFunctionPasses = new llvm::FunctionPassManager(mpModule); 38 mPerFunctionPasses->add(new llvm::TargetData(*mpTargetData)); 39 40 llvm::createStandardFunctionPasses(mPerFunctionPasses, 41 mCodeGenOpts.OptimizationLevel); 42 } 43 return; 44} 45 46void Backend::CreateModulePasses() { 47 if (!mPerModulePasses) { 48 mPerModulePasses = new llvm::PassManager(); 49 mPerModulePasses->add(new llvm::TargetData(*mpTargetData)); 50 51 llvm::createStandardModulePasses(mPerModulePasses, 52 mCodeGenOpts.OptimizationLevel, 53 mCodeGenOpts.OptimizeSize, 54 mCodeGenOpts.UnitAtATime, 55 mCodeGenOpts.UnrollLoops, 56 /* SimplifyLibCalls = */true, 57 /* HaveExceptions = */false, 58 /* InliningPass = */NULL); 59 } 60 return; 61} 62 63bool Backend::CreateCodeGenPasses() { 64 if ((mOT != Slang::OT_Assembly) && (mOT != Slang::OT_Object)) 65 return true; 66 67 // Now we add passes for code emitting 68 if (mCodeGenPasses) { 69 return true; 70 } else { 71 mCodeGenPasses = new llvm::FunctionPassManager(mpModule); 72 mCodeGenPasses->add(new llvm::TargetData(*mpTargetData)); 73 } 74 75 // Create the TargetMachine for generating code. 76 std::string Triple = mpModule->getTargetTriple(); 77 78 std::string Error; 79 const llvm::Target* TargetInfo = 80 llvm::TargetRegistry::lookupTarget(Triple, Error); 81 if (TargetInfo == NULL) { 82 mDiags.Report(clang::diag::err_fe_unable_to_create_target) << Error; 83 return false; 84 } 85 86 llvm::NoFramePointerElim = mCodeGenOpts.DisableFPElim; 87 88 // Use hardware FPU. 89 // 90 // FIXME: Need to detect the CPU capability and decide whether to use softfp. 91 // To use softfp, change following 2 lines to 92 // 93 // llvm::FloatABIType = llvm::FloatABI::Soft; 94 // llvm::UseSoftFloat = true; 95 llvm::FloatABIType = llvm::FloatABI::Hard; 96 llvm::UseSoftFloat = false; 97 98 // BCC needs all unknown symbols resolved at compilation time. So we don't 99 // need any relocation model. 100 llvm::TargetMachine::setRelocationModel(llvm::Reloc::Static); 101 102 103 // The target with pointer size greater than 32 (e.g. x86_64 architecture) may 104 // need large data address model 105 if (mpTargetData->getPointerSizeInBits() > 32) 106 llvm::TargetMachine::setCodeModel(llvm::CodeModel::Medium); 107 else 108 // This is set for the linker (specify how large of the virtual addresses we 109 // can access for all unknown symbols.) 110 111 llvm::TargetMachine::setCodeModel(llvm::CodeModel::Small); 112 113 // Setup feature string 114 std::string FeaturesStr; 115 if (mTargetOpts.CPU.size() || mTargetOpts.Features.size()) { 116 llvm::SubtargetFeatures Features; 117 118 Features.setCPU(mTargetOpts.CPU); 119 120 for (std::vector<std::string>::const_iterator 121 I = mTargetOpts.Features.begin(), E = mTargetOpts.Features.end(); 122 I != E; 123 I++) 124 Features.AddFeature(*I); 125 126 FeaturesStr = Features.getString(); 127 } 128 llvm::TargetMachine *TM = 129 TargetInfo->createTargetMachine(Triple, FeaturesStr); 130 131 // Register scheduler 132 llvm::RegisterScheduler::setDefault(llvm::createDefaultScheduler); 133 134 // Register allocation policy: 135 // createFastRegisterAllocator: fast but bad quality 136 // createLinearScanRegisterAllocator: not so fast but good quality 137 llvm::RegisterRegAlloc::setDefault((mCodeGenOpts.OptimizationLevel == 0) ? 138 llvm::createFastRegisterAllocator : 139 llvm::createLinearScanRegisterAllocator); 140 141 llvm::CodeGenOpt::Level OptLevel = llvm::CodeGenOpt::Default; 142 if (mCodeGenOpts.OptimizationLevel == 0) 143 OptLevel = llvm::CodeGenOpt::None; 144 else if (mCodeGenOpts.OptimizationLevel == 3) 145 OptLevel = llvm::CodeGenOpt::Aggressive; 146 147 llvm::TargetMachine::CodeGenFileType CGFT = 148 llvm::TargetMachine::CGFT_AssemblyFile; 149 if (mOT == Slang::OT_Object) 150 CGFT = llvm::TargetMachine::CGFT_ObjectFile; 151 if (TM->addPassesToEmitFile(*mCodeGenPasses, FormattedOutStream, 152 CGFT, OptLevel)) { 153 mDiags.Report(clang::diag::err_fe_unable_to_interface_with_target); 154 return false; 155 } 156 157 return true; 158} 159 160Backend::Backend(clang::Diagnostic &Diags, 161 const clang::CodeGenOptions &CodeGenOpts, 162 const clang::TargetOptions &TargetOpts, 163 const PragmaList &Pragmas, 164 llvm::raw_ostream *OS, 165 Slang::OutputType OT) 166 : ASTConsumer(), 167 mCodeGenOpts(CodeGenOpts), 168 mTargetOpts(TargetOpts), 169 mpOS(OS), 170 mOT(OT), 171 mpTargetData(NULL), 172 mGen(NULL), 173 mPerFunctionPasses(NULL), 174 mPerModulePasses(NULL), 175 mCodeGenPasses(NULL), 176 mLLVMContext(llvm::getGlobalContext()), 177 mDiags(Diags), 178 mpModule(NULL), 179 mPragmas(Pragmas) { 180 FormattedOutStream.setStream(*mpOS, 181 llvm::formatted_raw_ostream::PRESERVE_STREAM); 182 mGen = CreateLLVMCodeGen(mDiags, "", mCodeGenOpts, mLLVMContext); 183 return; 184} 185 186void Backend::Initialize(clang::ASTContext &Ctx) { 187 mGen->Initialize(Ctx); 188 189 mpModule = mGen->GetModule(); 190 mpTargetData = new llvm::TargetData(Slang::TargetDescription); 191 192 return; 193} 194 195void Backend::HandleTopLevelDecl(clang::DeclGroupRef D) { 196 mGen->HandleTopLevelDecl(D); 197 return; 198} 199 200void Backend::HandleTranslationUnit(clang::ASTContext &Ctx) { 201 mGen->HandleTranslationUnit(Ctx); 202 203 // Here, we complete a translation unit (whole translation unit is now in LLVM 204 // IR). Now, interact with LLVM backend to generate actual machine code (asm 205 // or machine code, whatever.) 206 207 // Silently ignore if we weren't initialized for some reason. 208 if (!mpModule || !mpTargetData) 209 return; 210 211 llvm::Module *M = mGen->ReleaseModule(); 212 if (!M) { 213 // The module has been released by IR gen on failures, do not double free. 214 mpModule = NULL; 215 return; 216 } 217 218 assert(mpModule == M && "Unexpected module change during LLVM IR generation"); 219 220 // Insert #pragma information into metadata section of module 221 if (!mPragmas.empty()) { 222 llvm::NamedMDNode *PragmaMetadata = 223 mpModule->getOrInsertNamedMetadata(Slang::PragmaMetadataName); 224 for (PragmaList::const_iterator I = mPragmas.begin(), E = mPragmas.end(); 225 I != E; 226 I++) { 227 llvm::SmallVector<llvm::Value*, 2> Pragma; 228 // Name goes first 229 Pragma.push_back(llvm::MDString::get(mLLVMContext, I->first)); 230 // And then value 231 Pragma.push_back(llvm::MDString::get(mLLVMContext, I->second)); 232 // Create MDNode and insert into PragmaMetadata 233 PragmaMetadata->addOperand( 234 llvm::MDNode::get(mLLVMContext, Pragma.data(), Pragma.size())); 235 } 236 } 237 238 HandleTranslationUnitEx(Ctx); 239 240 // Create passes for optimization and code emission 241 242 // Create and run per-function passes 243 CreateFunctionPasses(); 244 if (mPerFunctionPasses) { 245 mPerFunctionPasses->doInitialization(); 246 247 for (llvm::Module::iterator I = mpModule->begin(), E = mpModule->end(); 248 I != E; 249 I++) 250 if (!I->isDeclaration()) 251 mPerFunctionPasses->run(*I); 252 253 mPerFunctionPasses->doFinalization(); 254 } 255 256 // Create and run module passes 257 CreateModulePasses(); 258 if (mPerModulePasses) 259 mPerModulePasses->run(*mpModule); 260 261 switch (mOT) { 262 case Slang::OT_Assembly: 263 case Slang::OT_Object: { 264 if (!CreateCodeGenPasses()) 265 return; 266 267 mCodeGenPasses->doInitialization(); 268 269 for (llvm::Module::iterator I = mpModule->begin(), E = mpModule->end(); 270 I != E; 271 I++) 272 if (!I->isDeclaration()) 273 mCodeGenPasses->run(*I); 274 275 mCodeGenPasses->doFinalization(); 276 break; 277 } 278 case Slang::OT_LLVMAssembly: { 279 llvm::PassManager *LLEmitPM = new llvm::PassManager(); 280 LLEmitPM->add(llvm::createPrintModulePass(&FormattedOutStream)); 281 LLEmitPM->run(*mpModule); 282 break; 283 } 284 case Slang::OT_Bitcode: { 285 llvm::PassManager *BCEmitPM = new llvm::PassManager(); 286 BCEmitPM->add(llvm::createBitcodeWriterPass(FormattedOutStream)); 287 BCEmitPM->run(*mpModule); 288 break; 289 } 290 case Slang::OT_Nothing: { 291 return; 292 } 293 default: { 294 assert(false && "Unknown output type"); 295 } 296 } 297 298 FormattedOutStream.flush(); 299 300 return; 301} 302 303void Backend::HandleTagDeclDefinition(clang::TagDecl *D) { 304 mGen->HandleTagDeclDefinition(D); 305 return; 306} 307 308void Backend::CompleteTentativeDefinition(clang::VarDecl *D) { 309 mGen->CompleteTentativeDefinition(D); 310 return; 311} 312 313Backend::~Backend() { 314 delete mpModule; 315 delete mpTargetData; 316 delete mGen; 317 delete mPerFunctionPasses; 318 delete mPerModulePasses; 319 delete mCodeGenPasses; 320 return; 321} 322