MachineModuleInfo.cpp revision 4e0d6a7d48464188a1a25b544a6355326d3fd3bf
1//===-- llvm/CodeGen/MachineModuleInfo.cpp ----------------------*- C++ -*-===// 2// 3// The LLVM Compiler Infrastructure 4// 5// This file is distributed under the University of Illinois Open Source 6// License. See LICENSE.TXT for details. 7// 8//===----------------------------------------------------------------------===// 9 10#include "llvm/CodeGen/MachineModuleInfo.h" 11 12#include "llvm/Constants.h" 13#include "llvm/Analysis/ValueTracking.h" 14#include "llvm/CodeGen/MachineFunctionPass.h" 15#include "llvm/CodeGen/MachineFunction.h" 16#include "llvm/CodeGen/Passes.h" 17#include "llvm/Target/TargetInstrInfo.h" 18#include "llvm/Target/TargetMachine.h" 19#include "llvm/Target/TargetOptions.h" 20#include "llvm/DerivedTypes.h" 21#include "llvm/GlobalVariable.h" 22#include "llvm/Intrinsics.h" 23#include "llvm/Instructions.h" 24#include "llvm/Module.h" 25#include "llvm/Support/Dwarf.h" 26#include "llvm/Support/Streams.h" 27using namespace llvm; 28using namespace llvm::dwarf; 29 30// Handle the Pass registration stuff necessary to use TargetData's. 31static RegisterPass<MachineModuleInfo> 32X("machinemoduleinfo", "Module Information"); 33char MachineModuleInfo::ID = 0; 34 35//===----------------------------------------------------------------------===// 36 37MachineModuleInfo::MachineModuleInfo() 38: ImmutablePass(&ID) 39, Lines() 40, LabelIDList() 41, FrameMoves() 42, LandingPads() 43, Personalities() 44, CallsEHReturn(0) 45, CallsUnwindInit(0) 46, DbgInfoAvailable(false) 47{ 48 // Always emit "no personality" info 49 Personalities.push_back(NULL); 50} 51MachineModuleInfo::~MachineModuleInfo() { 52 53} 54 55/// doInitialization - Initialize the state for a new module. 56/// 57bool MachineModuleInfo::doInitialization() { 58 return false; 59} 60 61/// doFinalization - Tear down the state after completion of a module. 62/// 63bool MachineModuleInfo::doFinalization() { 64 return false; 65} 66 67/// BeginFunction - Begin gathering function meta information. 68/// 69void MachineModuleInfo::BeginFunction(MachineFunction *MF) { 70 // Coming soon. 71} 72 73/// EndFunction - Discard function meta information. 74/// 75void MachineModuleInfo::EndFunction() { 76 // Clean up frame info. 77 FrameMoves.clear(); 78 79 // Clean up exception info. 80 LandingPads.clear(); 81 TypeInfos.clear(); 82 FilterIds.clear(); 83 FilterEnds.clear(); 84 CallsEHReturn = 0; 85 CallsUnwindInit = 0; 86} 87 88/// AnalyzeModule - Scan the module for global debug information. 89/// 90void MachineModuleInfo::AnalyzeModule(Module &M) { 91 // Insert functions in the llvm.used array into UsedFunctions. 92 GlobalVariable *GV = M.getGlobalVariable("llvm.used"); 93 if (!GV || !GV->hasInitializer()) return; 94 95 // Should be an array of 'i8*'. 96 ConstantArray *InitList = dyn_cast<ConstantArray>(GV->getInitializer()); 97 if (InitList == 0) return; 98 99 for (unsigned i = 0, e = InitList->getNumOperands(); i != e; ++i) { 100 if (ConstantExpr *CE = dyn_cast<ConstantExpr>(InitList->getOperand(i))) 101 if (CE->getOpcode() == Instruction::BitCast) 102 if (Function *F = dyn_cast<Function>(CE->getOperand(0))) 103 UsedFunctions.insert(F); 104 } 105} 106 107//===-EH-------------------------------------------------------------------===// 108 109/// getOrCreateLandingPadInfo - Find or create an LandingPadInfo for the 110/// specified MachineBasicBlock. 111LandingPadInfo &MachineModuleInfo::getOrCreateLandingPadInfo 112 (MachineBasicBlock *LandingPad) { 113 unsigned N = LandingPads.size(); 114 for (unsigned i = 0; i < N; ++i) { 115 LandingPadInfo &LP = LandingPads[i]; 116 if (LP.LandingPadBlock == LandingPad) 117 return LP; 118 } 119 120 LandingPads.push_back(LandingPadInfo(LandingPad)); 121 return LandingPads[N]; 122} 123 124/// addInvoke - Provide the begin and end labels of an invoke style call and 125/// associate it with a try landing pad block. 126void MachineModuleInfo::addInvoke(MachineBasicBlock *LandingPad, 127 unsigned BeginLabel, unsigned EndLabel) { 128 LandingPadInfo &LP = getOrCreateLandingPadInfo(LandingPad); 129 LP.BeginLabels.push_back(BeginLabel); 130 LP.EndLabels.push_back(EndLabel); 131} 132 133/// addLandingPad - Provide the label of a try LandingPad block. 134/// 135unsigned MachineModuleInfo::addLandingPad(MachineBasicBlock *LandingPad) { 136 unsigned LandingPadLabel = NextLabelID(); 137 LandingPadInfo &LP = getOrCreateLandingPadInfo(LandingPad); 138 LP.LandingPadLabel = LandingPadLabel; 139 return LandingPadLabel; 140} 141 142/// addPersonality - Provide the personality function for the exception 143/// information. 144void MachineModuleInfo::addPersonality(MachineBasicBlock *LandingPad, 145 Function *Personality) { 146 LandingPadInfo &LP = getOrCreateLandingPadInfo(LandingPad); 147 LP.Personality = Personality; 148 149 for (unsigned i = 0; i < Personalities.size(); ++i) 150 if (Personalities[i] == Personality) 151 return; 152 153 Personalities.push_back(Personality); 154} 155 156/// addCatchTypeInfo - Provide the catch typeinfo for a landing pad. 157/// 158void MachineModuleInfo::addCatchTypeInfo(MachineBasicBlock *LandingPad, 159 std::vector<GlobalVariable *> &TyInfo) { 160 LandingPadInfo &LP = getOrCreateLandingPadInfo(LandingPad); 161 for (unsigned N = TyInfo.size(); N; --N) 162 LP.TypeIds.push_back(getTypeIDFor(TyInfo[N - 1])); 163} 164 165/// addFilterTypeInfo - Provide the filter typeinfo for a landing pad. 166/// 167void MachineModuleInfo::addFilterTypeInfo(MachineBasicBlock *LandingPad, 168 std::vector<GlobalVariable *> &TyInfo) { 169 LandingPadInfo &LP = getOrCreateLandingPadInfo(LandingPad); 170 std::vector<unsigned> IdsInFilter(TyInfo.size()); 171 for (unsigned I = 0, E = TyInfo.size(); I != E; ++I) 172 IdsInFilter[I] = getTypeIDFor(TyInfo[I]); 173 LP.TypeIds.push_back(getFilterIDFor(IdsInFilter)); 174} 175 176/// addCleanup - Add a cleanup action for a landing pad. 177/// 178void MachineModuleInfo::addCleanup(MachineBasicBlock *LandingPad) { 179 LandingPadInfo &LP = getOrCreateLandingPadInfo(LandingPad); 180 LP.TypeIds.push_back(0); 181} 182 183/// TidyLandingPads - Remap landing pad labels and remove any deleted landing 184/// pads. 185void MachineModuleInfo::TidyLandingPads() { 186 for (unsigned i = 0; i != LandingPads.size(); ) { 187 LandingPadInfo &LandingPad = LandingPads[i]; 188 LandingPad.LandingPadLabel = MappedLabel(LandingPad.LandingPadLabel); 189 190 // Special case: we *should* emit LPs with null LP MBB. This indicates 191 // "nounwind" case. 192 if (!LandingPad.LandingPadLabel && LandingPad.LandingPadBlock) { 193 LandingPads.erase(LandingPads.begin() + i); 194 continue; 195 } 196 197 for (unsigned j=0; j != LandingPads[i].BeginLabels.size(); ) { 198 unsigned BeginLabel = MappedLabel(LandingPad.BeginLabels[j]); 199 unsigned EndLabel = MappedLabel(LandingPad.EndLabels[j]); 200 201 if (!BeginLabel || !EndLabel) { 202 LandingPad.BeginLabels.erase(LandingPad.BeginLabels.begin() + j); 203 LandingPad.EndLabels.erase(LandingPad.EndLabels.begin() + j); 204 continue; 205 } 206 207 LandingPad.BeginLabels[j] = BeginLabel; 208 LandingPad.EndLabels[j] = EndLabel; 209 ++j; 210 } 211 212 // Remove landing pads with no try-ranges. 213 if (LandingPads[i].BeginLabels.empty()) { 214 LandingPads.erase(LandingPads.begin() + i); 215 continue; 216 } 217 218 // If there is no landing pad, ensure that the list of typeids is empty. 219 // If the only typeid is a cleanup, this is the same as having no typeids. 220 if (!LandingPad.LandingPadBlock || 221 (LandingPad.TypeIds.size() == 1 && !LandingPad.TypeIds[0])) 222 LandingPad.TypeIds.clear(); 223 224 ++i; 225 } 226} 227 228/// getTypeIDFor - Return the type id for the specified typeinfo. This is 229/// function wide. 230unsigned MachineModuleInfo::getTypeIDFor(GlobalVariable *TI) { 231 for (unsigned i = 0, N = TypeInfos.size(); i != N; ++i) 232 if (TypeInfos[i] == TI) return i + 1; 233 234 TypeInfos.push_back(TI); 235 return TypeInfos.size(); 236} 237 238/// getFilterIDFor - Return the filter id for the specified typeinfos. This is 239/// function wide. 240int MachineModuleInfo::getFilterIDFor(std::vector<unsigned> &TyIds) { 241 // If the new filter coincides with the tail of an existing filter, then 242 // re-use the existing filter. Folding filters more than this requires 243 // re-ordering filters and/or their elements - probably not worth it. 244 for (std::vector<unsigned>::iterator I = FilterEnds.begin(), 245 E = FilterEnds.end(); I != E; ++I) { 246 unsigned i = *I, j = TyIds.size(); 247 248 while (i && j) 249 if (FilterIds[--i] != TyIds[--j]) 250 goto try_next; 251 252 if (!j) 253 // The new filter coincides with range [i, end) of the existing filter. 254 return -(1 + i); 255 256try_next:; 257 } 258 259 // Add the new filter. 260 int FilterID = -(1 + FilterIds.size()); 261 FilterIds.reserve(FilterIds.size() + TyIds.size() + 1); 262 for (unsigned I = 0, N = TyIds.size(); I != N; ++I) 263 FilterIds.push_back(TyIds[I]); 264 FilterEnds.push_back(FilterIds.size()); 265 FilterIds.push_back(0); // terminator 266 return FilterID; 267} 268 269/// getPersonality - Return the personality function for the current function. 270Function *MachineModuleInfo::getPersonality() const { 271 // FIXME: Until PR1414 will be fixed, we're using 1 personality function per 272 // function 273 return !LandingPads.empty() ? LandingPads[0].Personality : NULL; 274} 275 276/// getPersonalityIndex - Return unique index for current personality 277/// function. NULL personality function should always get zero index. 278unsigned MachineModuleInfo::getPersonalityIndex() const { 279 const Function* Personality = NULL; 280 281 // Scan landing pads. If there is at least one non-NULL personality - use it. 282 for (unsigned i = 0; i != LandingPads.size(); ++i) 283 if (LandingPads[i].Personality) { 284 Personality = LandingPads[i].Personality; 285 break; 286 } 287 288 for (unsigned i = 0; i < Personalities.size(); ++i) { 289 if (Personalities[i] == Personality) 290 return i; 291 } 292 293 // This should never happen 294 assert(0 && "Personality function should be set!"); 295 return 0; 296} 297 298//===----------------------------------------------------------------------===// 299/// DebugLabelFolding pass - This pass prunes out redundant labels. This allows 300/// a info consumer to determine if the range of two labels is empty, by seeing 301/// if the labels map to the same reduced label. 302 303namespace llvm { 304 305struct DebugLabelFolder : public MachineFunctionPass { 306 static char ID; 307 DebugLabelFolder() : MachineFunctionPass(&ID) {} 308 309 virtual void getAnalysisUsage(AnalysisUsage &AU) const { 310 AU.addPreservedID(MachineLoopInfoID); 311 AU.addPreservedID(MachineDominatorsID); 312 MachineFunctionPass::getAnalysisUsage(AU); 313 } 314 315 virtual bool runOnMachineFunction(MachineFunction &MF); 316 virtual const char *getPassName() const { return "Label Folder"; } 317}; 318 319char DebugLabelFolder::ID = 0; 320 321bool DebugLabelFolder::runOnMachineFunction(MachineFunction &MF) { 322 // Get machine module info. 323 MachineModuleInfo *MMI = getAnalysisIfAvailable<MachineModuleInfo>(); 324 if (!MMI) return false; 325 326 // Track if change is made. 327 bool MadeChange = false; 328 // No prior label to begin. 329 unsigned PriorLabel = 0; 330 331 // Iterate through basic blocks. 332 for (MachineFunction::iterator BB = MF.begin(), E = MF.end(); 333 BB != E; ++BB) { 334 // Iterate through instructions. 335 for (MachineBasicBlock::iterator I = BB->begin(), E = BB->end(); I != E; ) { 336 // Is it a label. 337 if (I->isDebugLabel()) { 338 // The label ID # is always operand #0, an immediate. 339 unsigned NextLabel = I->getOperand(0).getImm(); 340 341 // If there was an immediate prior label. 342 if (PriorLabel) { 343 // Remap the current label to prior label. 344 MMI->RemapLabel(NextLabel, PriorLabel); 345 // Delete the current label. 346 I = BB->erase(I); 347 // Indicate a change has been made. 348 MadeChange = true; 349 continue; 350 } else { 351 // Start a new round. 352 PriorLabel = NextLabel; 353 } 354 } else { 355 // No consecutive labels. 356 PriorLabel = 0; 357 } 358 359 ++I; 360 } 361 } 362 363 return MadeChange; 364} 365 366FunctionPass *createDebugLabelFoldingPass() { return new DebugLabelFolder(); } 367 368} 369 370