MachineModuleInfo.cpp revision 845012e6d31799c7fbd1193fa1af8ee2d12e9231
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/ErrorHandling.h" 27#include "llvm/Support/Streams.h" 28using namespace llvm; 29using namespace llvm::dwarf; 30 31// Handle the Pass registration stuff necessary to use TargetData's. 32static RegisterPass<MachineModuleInfo> 33X("machinemoduleinfo", "Module Information"); 34char MachineModuleInfo::ID = 0; 35 36//===----------------------------------------------------------------------===// 37 38MachineModuleInfo::MachineModuleInfo() 39: ImmutablePass(&ID) 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 (but not llvm.compiler.used) into 92 // UsedFunctions. 93 GlobalVariable *GV = M.getGlobalVariable("llvm.used"); 94 if (!GV || !GV->hasInitializer()) return; 95 96 // Should be an array of 'i8*'. 97 ConstantArray *InitList = dyn_cast<ConstantArray>(GV->getInitializer()); 98 if (InitList == 0) return; 99 100 for (unsigned i = 0, e = InitList->getNumOperands(); i != e; ++i) 101 if (Function *F = 102 dyn_cast<Function>(InitList->getOperand(i)->stripPointerCasts())) 103 UsedFunctions.insert(F); 104} 105 106//===-EH-------------------------------------------------------------------===// 107 108/// getOrCreateLandingPadInfo - Find or create an LandingPadInfo for the 109/// specified MachineBasicBlock. 110LandingPadInfo &MachineModuleInfo::getOrCreateLandingPadInfo 111 (MachineBasicBlock *LandingPad) { 112 unsigned N = LandingPads.size(); 113 for (unsigned i = 0; i < N; ++i) { 114 LandingPadInfo &LP = LandingPads[i]; 115 if (LP.LandingPadBlock == LandingPad) 116 return LP; 117 } 118 119 LandingPads.push_back(LandingPadInfo(LandingPad)); 120 return LandingPads[N]; 121} 122 123/// addInvoke - Provide the begin and end labels of an invoke style call and 124/// associate it with a try landing pad block. 125void MachineModuleInfo::addInvoke(MachineBasicBlock *LandingPad, 126 unsigned BeginLabel, unsigned EndLabel) { 127 LandingPadInfo &LP = getOrCreateLandingPadInfo(LandingPad); 128 LP.BeginLabels.push_back(BeginLabel); 129 LP.EndLabels.push_back(EndLabel); 130} 131 132/// addLandingPad - Provide the label of a try LandingPad block. 133/// 134unsigned MachineModuleInfo::addLandingPad(MachineBasicBlock *LandingPad) { 135 unsigned LandingPadLabel = NextLabelID(); 136 LandingPadInfo &LP = getOrCreateLandingPadInfo(LandingPad); 137 LP.LandingPadLabel = LandingPadLabel; 138 return LandingPadLabel; 139} 140 141/// addPersonality - Provide the personality function for the exception 142/// information. 143void MachineModuleInfo::addPersonality(MachineBasicBlock *LandingPad, 144 Function *Personality) { 145 LandingPadInfo &LP = getOrCreateLandingPadInfo(LandingPad); 146 LP.Personality = Personality; 147 148 for (unsigned i = 0; i < Personalities.size(); ++i) 149 if (Personalities[i] == Personality) 150 return; 151 152 Personalities.push_back(Personality); 153} 154 155/// addCatchTypeInfo - Provide the catch typeinfo for a landing pad. 156/// 157void MachineModuleInfo::addCatchTypeInfo(MachineBasicBlock *LandingPad, 158 std::vector<GlobalVariable *> &TyInfo) { 159 LandingPadInfo &LP = getOrCreateLandingPadInfo(LandingPad); 160 for (unsigned N = TyInfo.size(); N; --N) 161 LP.TypeIds.push_back(getTypeIDFor(TyInfo[N - 1])); 162} 163 164/// addFilterTypeInfo - Provide the filter typeinfo for a landing pad. 165/// 166void MachineModuleInfo::addFilterTypeInfo(MachineBasicBlock *LandingPad, 167 std::vector<GlobalVariable *> &TyInfo) { 168 LandingPadInfo &LP = getOrCreateLandingPadInfo(LandingPad); 169 std::vector<unsigned> IdsInFilter(TyInfo.size()); 170 for (unsigned I = 0, E = TyInfo.size(); I != E; ++I) 171 IdsInFilter[I] = getTypeIDFor(TyInfo[I]); 172 LP.TypeIds.push_back(getFilterIDFor(IdsInFilter)); 173} 174 175/// addCleanup - Add a cleanup action for a landing pad. 176/// 177void MachineModuleInfo::addCleanup(MachineBasicBlock *LandingPad) { 178 LandingPadInfo &LP = getOrCreateLandingPadInfo(LandingPad); 179 LP.TypeIds.push_back(0); 180} 181 182/// TidyLandingPads - Remap landing pad labels and remove any deleted landing 183/// pads. 184void MachineModuleInfo::TidyLandingPads() { 185 for (unsigned i = 0; i != LandingPads.size(); ) { 186 LandingPadInfo &LandingPad = LandingPads[i]; 187 LandingPad.LandingPadLabel = MappedLabel(LandingPad.LandingPadLabel); 188 189 // Special case: we *should* emit LPs with null LP MBB. This indicates 190 // "nounwind" case. 191 if (!LandingPad.LandingPadLabel && LandingPad.LandingPadBlock) { 192 LandingPads.erase(LandingPads.begin() + i); 193 continue; 194 } 195 196 for (unsigned j=0; j != LandingPads[i].BeginLabels.size(); ) { 197 unsigned BeginLabel = MappedLabel(LandingPad.BeginLabels[j]); 198 unsigned EndLabel = MappedLabel(LandingPad.EndLabels[j]); 199 200 if (!BeginLabel || !EndLabel) { 201 LandingPad.BeginLabels.erase(LandingPad.BeginLabels.begin() + j); 202 LandingPad.EndLabels.erase(LandingPad.EndLabels.begin() + j); 203 continue; 204 } 205 206 LandingPad.BeginLabels[j] = BeginLabel; 207 LandingPad.EndLabels[j] = EndLabel; 208 ++j; 209 } 210 211 // Remove landing pads with no try-ranges. 212 if (LandingPads[i].BeginLabels.empty()) { 213 LandingPads.erase(LandingPads.begin() + i); 214 continue; 215 } 216 217 // If there is no landing pad, ensure that the list of typeids is empty. 218 // If the only typeid is a cleanup, this is the same as having no typeids. 219 if (!LandingPad.LandingPadBlock || 220 (LandingPad.TypeIds.size() == 1 && !LandingPad.TypeIds[0])) 221 LandingPad.TypeIds.clear(); 222 223 ++i; 224 } 225} 226 227/// getTypeIDFor - Return the type id for the specified typeinfo. This is 228/// function wide. 229unsigned MachineModuleInfo::getTypeIDFor(GlobalVariable *TI) { 230 for (unsigned i = 0, N = TypeInfos.size(); i != N; ++i) 231 if (TypeInfos[i] == TI) return i + 1; 232 233 TypeInfos.push_back(TI); 234 return TypeInfos.size(); 235} 236 237/// getFilterIDFor - Return the filter id for the specified typeinfos. This is 238/// function wide. 239int MachineModuleInfo::getFilterIDFor(std::vector<unsigned> &TyIds) { 240 // If the new filter coincides with the tail of an existing filter, then 241 // re-use the existing filter. Folding filters more than this requires 242 // re-ordering filters and/or their elements - probably not worth it. 243 for (std::vector<unsigned>::iterator I = FilterEnds.begin(), 244 E = FilterEnds.end(); I != E; ++I) { 245 unsigned i = *I, j = TyIds.size(); 246 247 while (i && j) 248 if (FilterIds[--i] != TyIds[--j]) 249 goto try_next; 250 251 if (!j) 252 // The new filter coincides with range [i, end) of the existing filter. 253 return -(1 + i); 254 255try_next:; 256 } 257 258 // Add the new filter. 259 int FilterID = -(1 + FilterIds.size()); 260 FilterIds.reserve(FilterIds.size() + TyIds.size() + 1); 261 for (unsigned I = 0, N = TyIds.size(); I != N; ++I) 262 FilterIds.push_back(TyIds[I]); 263 FilterEnds.push_back(FilterIds.size()); 264 FilterIds.push_back(0); // terminator 265 return FilterID; 266} 267 268/// getPersonality - Return the personality function for the current function. 269Function *MachineModuleInfo::getPersonality() const { 270 // FIXME: Until PR1414 will be fixed, we're using 1 personality function per 271 // function 272 return !LandingPads.empty() ? LandingPads[0].Personality : NULL; 273} 274 275/// getPersonalityIndex - Return unique index for current personality 276/// function. NULL personality function should always get zero index. 277unsigned MachineModuleInfo::getPersonalityIndex() const { 278 const Function* Personality = NULL; 279 280 // Scan landing pads. If there is at least one non-NULL personality - use it. 281 for (unsigned i = 0; i != LandingPads.size(); ++i) 282 if (LandingPads[i].Personality) { 283 Personality = LandingPads[i].Personality; 284 break; 285 } 286 287 for (unsigned i = 0; i < Personalities.size(); ++i) { 288 if (Personalities[i] == Personality) 289 return i; 290 } 291 292 // This should never happen 293 llvm_unreachable("Personality function should be set!"); 294 return 0; 295} 296 297//===----------------------------------------------------------------------===// 298/// DebugLabelFolding pass - This pass prunes out redundant labels. This allows 299/// a info consumer to determine if the range of two labels is empty, by seeing 300/// if the labels map to the same reduced label. 301 302namespace llvm { 303 304struct DebugLabelFolder : public MachineFunctionPass { 305 static char ID; 306 DebugLabelFolder() : MachineFunctionPass(&ID) {} 307 308 virtual void getAnalysisUsage(AnalysisUsage &AU) const { 309 AU.setPreservesCFG(); 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() && !MMI->isDbgLabelUsed(I->getOperand(0).getImm())){ 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