slang_backend.cpp revision 41ebf534161bb67f6207a070c1f6a895dc853408
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/TargetData.h" 24#include "llvm/Target/TargetMachine.h" 25#include "llvm/Target/TargetOptions.h" 26#include "llvm/Target/TargetRegistry.h" 27#include "llvm/Target/SubtargetFeature.h" 28 29#include "llvm/CodeGen/RegAllocRegistry.h" 30#include "llvm/CodeGen/SchedulerRegistry.h" 31 32#include "llvm/Assembly/PrintModulePass.h" 33#include "llvm/Bitcode/ReaderWriter.h" 34 35#include "clang/AST/Decl.h" 36#include "clang/AST/DeclGroup.h" 37#include "clang/AST/ASTContext.h" 38 39#include "clang/Basic/TargetInfo.h" 40#include "clang/Basic/Diagnostic.h" 41#include "clang/Basic/TargetOptions.h" 42 43#include "clang/Frontend/CodeGenOptions.h" 44#include "clang/Frontend/FrontendDiagnostic.h" 45 46#include "clang/CodeGen/ModuleBuilder.h" 47 48#include "slang.h" 49 50using namespace slang; 51 52void Backend::CreateFunctionPasses() { 53 if (!mPerFunctionPasses) { 54 mPerFunctionPasses = new llvm::FunctionPassManager(mpModule); 55 mPerFunctionPasses->add(new llvm::TargetData(mpModule)); 56 57 llvm::createStandardFunctionPasses(mPerFunctionPasses, 58 mCodeGenOpts.OptimizationLevel); 59 } 60 return; 61} 62 63void Backend::CreateModulePasses() { 64 if (!mPerModulePasses) { 65 mPerModulePasses = new llvm::PassManager(); 66 mPerModulePasses->add(new llvm::TargetData(mpModule)); 67 68 llvm::createStandardModulePasses(mPerModulePasses, 69 mCodeGenOpts.OptimizationLevel, 70 mCodeGenOpts.OptimizeSize, 71 mCodeGenOpts.UnitAtATime, 72 mCodeGenOpts.UnrollLoops, 73 /* SimplifyLibCalls = */true, 74 /* HaveExceptions = */false, 75 /* InliningPass = */NULL); 76 } 77 return; 78} 79 80bool Backend::CreateCodeGenPasses() { 81 if ((mOT != Slang::OT_Assembly) && (mOT != Slang::OT_Object)) 82 return true; 83 84 // Now we add passes for code emitting 85 if (mCodeGenPasses) { 86 return true; 87 } else { 88 mCodeGenPasses = new llvm::FunctionPassManager(mpModule); 89 mCodeGenPasses->add(new llvm::TargetData(mpModule)); 90 } 91 92 // Create the TargetMachine for generating code. 93 std::string Triple = mpModule->getTargetTriple(); 94 95 std::string Error; 96 const llvm::Target* TargetInfo = 97 llvm::TargetRegistry::lookupTarget(Triple, Error); 98 if (TargetInfo == NULL) { 99 mDiags.Report(clang::diag::err_fe_unable_to_create_target) << Error; 100 return false; 101 } 102 103 llvm::NoFramePointerElim = mCodeGenOpts.DisableFPElim; 104 105 // Use hardware FPU. 106 // 107 // FIXME: Need to detect the CPU capability and decide whether to use softfp. 108 // To use softfp, change following 2 lines to 109 // 110 // llvm::FloatABIType = llvm::FloatABI::Soft; 111 // llvm::UseSoftFloat = true; 112 llvm::FloatABIType = llvm::FloatABI::Hard; 113 llvm::UseSoftFloat = false; 114 115 // BCC needs all unknown symbols resolved at compilation time. So we don't 116 // need any relocation model. 117 llvm::TargetMachine::setRelocationModel(llvm::Reloc::Static); 118 119 120 // This is set for the linker (specify how large of the virtual addresses we 121 // can access for all unknown symbols.) 122 if (mpModule->getPointerSize() == llvm::Module::Pointer32) 123 llvm::TargetMachine::setCodeModel(llvm::CodeModel::Small); 124 else 125 // The target may have pointer size greater than 32 (e.g. x86_64 126 // architecture) may need large data address model 127 llvm::TargetMachine::setCodeModel(llvm::CodeModel::Medium); 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 mGen(NULL), 188 mPerFunctionPasses(NULL), 189 mPerModulePasses(NULL), 190 mCodeGenPasses(NULL), 191 mLLVMContext(llvm::getGlobalContext()), 192 mDiags(Diags), 193 mpModule(NULL), 194 mPragmas(Pragmas) { 195 FormattedOutStream.setStream(*mpOS, 196 llvm::formatted_raw_ostream::PRESERVE_STREAM); 197 mGen = CreateLLVMCodeGen(mDiags, "", mCodeGenOpts, mLLVMContext); 198 return; 199} 200 201void Backend::Initialize(clang::ASTContext &Ctx) { 202 mGen->Initialize(Ctx); 203 204 mpModule = mGen->GetModule(); 205 206 return; 207} 208 209void Backend::HandleTopLevelDecl(clang::DeclGroupRef D) { 210 mGen->HandleTopLevelDecl(D); 211 return; 212} 213 214void Backend::HandleTranslationUnit(clang::ASTContext &Ctx) { 215 mGen->HandleTranslationUnit(Ctx); 216 217 // Here, we complete a translation unit (whole translation unit is now in LLVM 218 // IR). Now, interact with LLVM backend to generate actual machine code (asm 219 // or machine code, whatever.) 220 221 // Silently ignore if we weren't initialized for some reason. 222 if (!mpModule) 223 return; 224 225 llvm::Module *M = mGen->ReleaseModule(); 226 if (!M) { 227 // The module has been released by IR gen on failures, do not double free. 228 mpModule = NULL; 229 return; 230 } 231 232 assert(mpModule == M && "Unexpected module change during LLVM IR generation"); 233 234 // Insert #pragma information into metadata section of module 235 if (!mPragmas.empty()) { 236 llvm::NamedMDNode *PragmaMetadata = 237 mpModule->getOrInsertNamedMetadata(Slang::PragmaMetadataName); 238 for (PragmaList::const_iterator I = mPragmas.begin(), E = mPragmas.end(); 239 I != E; 240 I++) { 241 llvm::SmallVector<llvm::Value*, 2> Pragma; 242 // Name goes first 243 Pragma.push_back(llvm::MDString::get(mLLVMContext, I->first)); 244 // And then value 245 Pragma.push_back(llvm::MDString::get(mLLVMContext, I->second)); 246 // Create MDNode and insert into PragmaMetadata 247 PragmaMetadata->addOperand( 248 llvm::MDNode::get(mLLVMContext, Pragma.data(), Pragma.size())); 249 } 250 } 251 252 HandleTranslationUnitEx(Ctx); 253 254 // Create passes for optimization and code emission 255 256 // Create and run per-function passes 257 CreateFunctionPasses(); 258 if (mPerFunctionPasses) { 259 mPerFunctionPasses->doInitialization(); 260 261 for (llvm::Module::iterator I = mpModule->begin(), E = mpModule->end(); 262 I != E; 263 I++) 264 if (!I->isDeclaration()) 265 mPerFunctionPasses->run(*I); 266 267 mPerFunctionPasses->doFinalization(); 268 } 269 270 // Create and run module passes 271 CreateModulePasses(); 272 if (mPerModulePasses) 273 mPerModulePasses->run(*mpModule); 274 275 switch (mOT) { 276 case Slang::OT_Assembly: 277 case Slang::OT_Object: { 278 if (!CreateCodeGenPasses()) 279 return; 280 281 mCodeGenPasses->doInitialization(); 282 283 for (llvm::Module::iterator I = mpModule->begin(), E = mpModule->end(); 284 I != E; 285 I++) 286 if (!I->isDeclaration()) 287 mCodeGenPasses->run(*I); 288 289 mCodeGenPasses->doFinalization(); 290 break; 291 } 292 case Slang::OT_LLVMAssembly: { 293 llvm::PassManager *LLEmitPM = new llvm::PassManager(); 294 LLEmitPM->add(llvm::createPrintModulePass(&FormattedOutStream)); 295 LLEmitPM->run(*mpModule); 296 break; 297 } 298 case Slang::OT_Bitcode: { 299 llvm::PassManager *BCEmitPM = new llvm::PassManager(); 300 BCEmitPM->add(llvm::createBitcodeWriterPass(FormattedOutStream)); 301 BCEmitPM->run(*mpModule); 302 break; 303 } 304 case Slang::OT_Nothing: { 305 return; 306 } 307 default: { 308 assert(false && "Unknown output type"); 309 } 310 } 311 312 FormattedOutStream.flush(); 313 314 return; 315} 316 317void Backend::HandleTagDeclDefinition(clang::TagDecl *D) { 318 mGen->HandleTagDeclDefinition(D); 319 return; 320} 321 322void Backend::CompleteTentativeDefinition(clang::VarDecl *D) { 323 mGen->CompleteTentativeDefinition(D); 324 return; 325} 326 327Backend::~Backend() { 328 delete mpModule; 329 delete mGen; 330 delete mPerFunctionPasses; 331 delete mPerModulePasses; 332 delete mCodeGenPasses; 333 return; 334} 335