CDSPass.cpp

   1 //===-- CDSPass.cpp - xxx -------------------------------===//
   2 //
   3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
   4 // See https://llvm.org/LICENSE.txt for license information.
   5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
   6 // This file is distributed under the University of Illinois Open Source
   7 // License. See LICENSE.TXT for details.
   8 //
   9 //===----------------------------------------------------------------------===//
  10 //
  11 // This file is a modified version of ThreadSanitizer.cpp, a part of a race detector.
  12 //
  13 // The tool is under development, for the details about previous versions see
  14 // http://code.google.com/p/data-race-test
  15 //
  16 // The instrumentation phase is quite simple:
  17 //   - Insert calls to run-time library before every memory access.
  18 //      - Optimizations may apply to avoid instrumenting some of the accesses.
  19 //   - Insert calls at function entry/exit.
  20 // The rest is handled by the run-time library.
  21 //===----------------------------------------------------------------------===//
  22
  23 #include "llvm/ADT/Statistic.h"
  24 #include "llvm/ADT/StringExtras.h"
  25 #include "llvm/ADT/SmallString.h"
  26 #include "llvm/Analysis/ValueTracking.h"
  27 #include "llvm/Analysis/CaptureTracking.h"
  28 #include "llvm/IR/BasicBlock.h"
  29 #include "llvm/IR/Function.h"
  30 #include "llvm/IR/IRBuilder.h"
  31 #include "llvm/IR/Instructions.h"
  32 #include "llvm/IR/IntrinsicInst.h"
  33 #include "llvm/IR/LLVMContext.h"
  34 #include "llvm/IR/LegacyPassManager.h"
  35 #include "llvm/IR/Module.h"
  36 #include "llvm/IR/PassManager.h"
  37 #include "llvm/Pass.h"
  38 #include "llvm/ProfileData/InstrProf.h"
  39 #include "llvm/Support/raw_ostream.h"
  40 #include "llvm/Support/AtomicOrdering.h"
  41 #include "llvm/Support/Debug.h"
  42 #include "llvm/Transforms/Scalar.h"
  43 #include "llvm/Transforms/Utils/BasicBlockUtils.h"
  44 #include "llvm/Transforms/Utils/EscapeEnumerator.h"
  45 #include "llvm/Transforms/IPO/PassManagerBuilder.h"
  46 #include <vector>
  47
  48 using namespace llvm;
  49
  50 #define DEBUG_TYPE "CDS"
  51 #include <llvm/IR/DebugLoc.h>
  52
  53 Value *getPosition( Instruction * I, IRBuilder <> IRB, bool print = false)
  54 {
  55         const DebugLoc & debug_location = I->getDebugLoc ();
  56         std::string position_string;
  57         {
  58                 llvm::raw_string_ostream position_stream (position_string);
  59                 debug_location . print (position_stream);
  60         }
  61
  62         if (print) {
  63                 errs() << position_string << "\n";
  64         }
  65
  66         return IRB.CreateGlobalStringPtr (position_string);
  67 }
  68
  69 STATISTIC(NumInstrumentedReads, "Number of instrumented reads");
  70 STATISTIC(NumInstrumentedWrites, "Number of instrumented writes");
  71 STATISTIC(NumOmittedReadsBeforeWrite,
  72           "Number of reads ignored due to following writes");
  73 STATISTIC(NumAccessesWithBadSize, "Number of accesses with bad size");
  74 // STATISTIC(NumInstrumentedVtableWrites, "Number of vtable ptr writes");
  75 // STATISTIC(NumInstrumentedVtableReads, "Number of vtable ptr reads");
  76 STATISTIC(NumOmittedReadsFromConstantGlobals,
  77           "Number of reads from constant globals");
  78 STATISTIC(NumOmittedReadsFromVtable, "Number of vtable reads");
  79 STATISTIC(NumOmittedNonCaptured, "Number of accesses ignored due to capturing");
  80
  81 // static const char *const kCDSModuleCtorName = "cds.module_ctor";
  82 // static const char *const kCDSInitName = "cds_init";
  83
  84 Type * OrdTy;
  85 Type * IntPtrTy;
  86 Type * Int8PtrTy;
  87 Type * Int16PtrTy;
  88 Type * Int32PtrTy;
  89 Type * Int64PtrTy;
  90
  91 Type * VoidTy;
  92
  93 static const size_t kNumberOfAccessSizes = 4;
  94
  95 int getAtomicOrderIndex(AtomicOrdering order) {
  96         switch (order) {
  97                 case AtomicOrdering::Monotonic:
  98                         return (int)AtomicOrderingCABI::relaxed;
  99                 //  case AtomicOrdering::Consume:         // not specified yet
 100                 //    return AtomicOrderingCABI::consume;
 101                 case AtomicOrdering::Acquire:
 102                         return (int)AtomicOrderingCABI::acquire;
 103                 case AtomicOrdering::Release:
 104                         return (int)AtomicOrderingCABI::release;
 105                 case AtomicOrdering::AcquireRelease:
 106                         return (int)AtomicOrderingCABI::acq_rel;
 107                 case AtomicOrdering::SequentiallyConsistent:
 108                         return (int)AtomicOrderingCABI::seq_cst;
 109                 default:
 110                         // unordered or Not Atomic
 111                         return -1;
 112         }
 113 }
 114
 115 AtomicOrderingCABI indexToAtomicOrder(int index) {
 116         switch (index) {
 117                 case 0:
 118                         return AtomicOrderingCABI::relaxed;
 119                 case 1:
 120                         return AtomicOrderingCABI::consume;
 121                 case 2:
 122                         return AtomicOrderingCABI::acquire;
 123                 case 3:
 124                         return AtomicOrderingCABI::release;
 125                 case 4:
 126                         return AtomicOrderingCABI::acq_rel;
 127                 case 5:
 128                         return AtomicOrderingCABI::seq_cst;
 129                 default:
 130                         errs() << "Bad Atomic index\n";
 131                         return AtomicOrderingCABI::seq_cst;
 132         }
 133 }
 134
 135 /* According to atomic_base.h: __cmpexch_failure_order */
 136 int AtomicCasFailureOrderIndex(int index) {
 137         AtomicOrderingCABI succ_order = indexToAtomicOrder(index);
 138         AtomicOrderingCABI fail_order;
 139         if (succ_order == AtomicOrderingCABI::acq_rel)
 140                 fail_order = AtomicOrderingCABI::acquire;
 141         else if (succ_order == AtomicOrderingCABI::release)
 142                 fail_order = AtomicOrderingCABI::relaxed;
 143         else
 144                 fail_order = succ_order;
 145
 146         return (int) fail_order;
 147 }
 148
 149 /* The original function checkSanitizerInterfaceFunction was defined
 150  * in llvm/Transforms/Utils/ModuleUtils.h
 151  */
 152 static Function * checkCDSPassInterfaceFunction(Constant *FuncOrBitcast) {
 153         if (isa<Function>(FuncOrBitcast))
 154                 return cast<Function>(FuncOrBitcast);
 155         FuncOrBitcast->print(errs());
 156         errs() << '\n';
 157         std::string Err;
 158         raw_string_ostream Stream(Err);
 159         Stream << "CDSPass interface function redefined: " << *FuncOrBitcast;
 160         report_fatal_error(Err);
 161 }
 162
 163 namespace {
 164         struct CDSPass : public FunctionPass {
 165                 CDSPass() : FunctionPass(ID) {}
 166                 StringRef getPassName() const override;
 167                 bool runOnFunction(Function &F) override;
 168                 bool doInitialization(Module &M) override;
 169                 static char ID;
 170
 171         private:
 172                 void initializeCallbacks(Module &M);
 173                 bool instrumentLoadOrStore(Instruction *I, const DataLayout &DL);
 174                 bool instrumentVolatile(Instruction *I, const DataLayout &DL);
 175                 bool instrumentMemIntrinsic(Instruction *I);
 176                 bool isAtomicCall(Instruction *I);
 177                 bool instrumentAtomic(Instruction *I, const DataLayout &DL);
 178                 bool instrumentAtomicCall(CallInst *CI, const DataLayout &DL);
 179                 bool shouldInstrumentBeforeAtomics(Instruction *I);
 180                 void chooseInstructionsToInstrument(SmallVectorImpl<Instruction *> &Local,
 181                                                                                         SmallVectorImpl<Instruction *> &All,
 182                                                                                         const DataLayout &DL);
 183                 bool addrPointsToConstantData(Value *Addr);
 184                 int getMemoryAccessFuncIndex(Value *Addr, const DataLayout &DL);
 185
 186                 Function * CDSFuncEntry;
 187                 Function * CDSFuncExit;
 188
 189                 Function * CDSLoad[kNumberOfAccessSizes];
 190                 Function * CDSStore[kNumberOfAccessSizes];
 191                 Function * CDSVolatileLoad[kNumberOfAccessSizes];
 192                 Function * CDSVolatileStore[kNumberOfAccessSizes];
 193                 Function * CDSAtomicInit[kNumberOfAccessSizes];
 194                 Function * CDSAtomicLoad[kNumberOfAccessSizes];
 195                 Function * CDSAtomicStore[kNumberOfAccessSizes];
 196                 Function * CDSAtomicRMW[AtomicRMWInst::LAST_BINOP + 1][kNumberOfAccessSizes];
 197                 Function * CDSAtomicCAS_V1[kNumberOfAccessSizes];
 198                 Function * CDSAtomicCAS_V2[kNumberOfAccessSizes];
 199                 Function * CDSAtomicThreadFence;
 200                 Function * MemmoveFn, * MemcpyFn, * MemsetFn;
 201                 // Function * CDSCtorFunction;
 202
 203                 std::vector<StringRef> AtomicFuncNames;
 204                 std::vector<StringRef> PartialAtomicFuncNames;
 205         };
 206 }
 207
 208 StringRef CDSPass::getPassName() const {
 209         return "CDSPass";
 210 }
 211
 212 void CDSPass::initializeCallbacks(Module &M) {
 213         LLVMContext &Ctx = M.getContext();
 214         AttributeList Attr;
 215         Attr = Attr.addAttribute(Ctx, AttributeList::FunctionIndex,
 216                         Attribute::NoUnwind);
 217
 218         Type * Int1Ty = Type::getInt1Ty(Ctx);
 219         Type * Int32Ty = Type::getInt32Ty(Ctx);
 220         OrdTy = Type::getInt32Ty(Ctx);
 221
 222         Int8PtrTy  = Type::getInt8PtrTy(Ctx);
 223         Int16PtrTy = Type::getInt16PtrTy(Ctx);
 224         Int32PtrTy = Type::getInt32PtrTy(Ctx);
 225         Int64PtrTy = Type::getInt64PtrTy(Ctx);
 226
 227         VoidTy = Type::getVoidTy(Ctx);
 228
 229         CDSFuncEntry = checkCDSPassInterfaceFunction(
 230                                                 M.getOrInsertFunction("cds_func_entry",
 231                                                 Attr, VoidTy, Int8PtrTy));
 232         CDSFuncExit = checkCDSPassInterfaceFunction(
 233                                                 M.getOrInsertFunction("cds_func_exit",
 234                                                 Attr, VoidTy, Int8PtrTy));
 235
 236         // Get the function to call from our untime library.
 237         for (unsigned i = 0; i < kNumberOfAccessSizes; i++) {
 238                 const unsigned ByteSize = 1U << i;
 239                 const unsigned BitSize = ByteSize * 8;
 240
 241                 std::string ByteSizeStr = utostr(ByteSize);
 242                 std::string BitSizeStr = utostr(BitSize);
 243
 244                 Type *Ty = Type::getIntNTy(Ctx, BitSize);
 245                 Type *PtrTy = Ty->getPointerTo();
 246
 247                 // uint8_t cds_atomic_load8 (void * obj, int atomic_index)
 248                 // void cds_atomic_store8 (void * obj, int atomic_index, uint8_t val)
 249                 SmallString<32> LoadName("cds_load" + BitSizeStr);
 250                 SmallString<32> StoreName("cds_store" + BitSizeStr);
 251                 SmallString<32> VolatileLoadName("cds_volatile_load" + BitSizeStr);
 252                 SmallString<32> VolatileStoreName("cds_volatile_store" + BitSizeStr);
 253                 SmallString<32> AtomicInitName("cds_atomic_init" + BitSizeStr);
 254                 SmallString<32> AtomicLoadName("cds_atomic_load" + BitSizeStr);
 255                 SmallString<32> AtomicStoreName("cds_atomic_store" + BitSizeStr);
 256
 257                 CDSLoad[i]  = checkCDSPassInterfaceFunction(
 258                                                         M.getOrInsertFunction(LoadName, Attr, VoidTy, PtrTy));
 259                 CDSStore[i] = checkCDSPassInterfaceFunction(
 260                                                         M.getOrInsertFunction(StoreName, Attr, VoidTy, PtrTy));
 261                 CDSVolatileLoad[i]  = checkCDSPassInterfaceFunction(
 262                                                                 M.getOrInsertFunction(VolatileLoadName,
 263                                                                 Attr, Ty, PtrTy, Int8PtrTy));
 264                 CDSVolatileStore[i] = checkCDSPassInterfaceFunction(
 265                                                                 M.getOrInsertFunction(VolatileStoreName,
 266                                                                 Attr, VoidTy, PtrTy, Ty, Int8PtrTy));
 267                 CDSAtomicInit[i] = checkCDSPassInterfaceFunction(
 268                                                         M.getOrInsertFunction(AtomicInitName,
 269                                                         Attr, VoidTy, PtrTy, Ty, Int8PtrTy));
 270                 CDSAtomicLoad[i]  = checkCDSPassInterfaceFunction(
 271                                                                 M.getOrInsertFunction(AtomicLoadName,
 272                                                                 Attr, Ty, PtrTy, OrdTy, Int8PtrTy));
 273                 CDSAtomicStore[i] = checkCDSPassInterfaceFunction(
 274                                                                 M.getOrInsertFunction(AtomicStoreName,
 275                                                                 Attr, VoidTy, PtrTy, Ty, OrdTy, Int8PtrTy));
 276
 277                 for (int op = AtomicRMWInst::FIRST_BINOP;
 278                         op <= AtomicRMWInst::LAST_BINOP; ++op) {
 279                         CDSAtomicRMW[op][i] = nullptr;
 280                         std::string NamePart;
 281
 282                         if (op == AtomicRMWInst::Xchg)
 283                                 NamePart = "_exchange";
 284                         else if (op == AtomicRMWInst::Add)
 285                                 NamePart = "_fetch_add";
 286                         else if (op == AtomicRMWInst::Sub)
 287                                 NamePart = "_fetch_sub";
 288                         else if (op == AtomicRMWInst::And)
 289                                 NamePart = "_fetch_and";
 290                         else if (op == AtomicRMWInst::Or)
 291                                 NamePart = "_fetch_or";
 292                         else if (op == AtomicRMWInst::Xor)
 293                                 NamePart = "_fetch_xor";
 294                         else
 295                                 continue;
 296
 297                         SmallString<32> AtomicRMWName("cds_atomic" + NamePart + BitSizeStr);
 298                         CDSAtomicRMW[op][i] = checkCDSPassInterfaceFunction(
 299                                                                         M.getOrInsertFunction(AtomicRMWName,
 300                                                                         Attr, Ty, PtrTy, Ty, OrdTy, Int8PtrTy));
 301                 }
 302
 303                 // only supportes strong version
 304                 SmallString<32> AtomicCASName_V1("cds_atomic_compare_exchange" + BitSizeStr + "_v1");
 305                 SmallString<32> AtomicCASName_V2("cds_atomic_compare_exchange" + BitSizeStr + "_v2");
 306                 CDSAtomicCAS_V1[i] = checkCDSPassInterfaceFunction(
 307                                                                 M.getOrInsertFunction(AtomicCASName_V1,
 308                                                                 Attr, Ty, PtrTy, Ty, Ty, OrdTy, OrdTy, Int8PtrTy));
 309                 CDSAtomicCAS_V2[i] = checkCDSPassInterfaceFunction(
 310                                                                 M.getOrInsertFunction(AtomicCASName_V2,
 311                                                                 Attr, Int1Ty, PtrTy, PtrTy, Ty, OrdTy, OrdTy, Int8PtrTy));
 312         }
 313
 314         CDSAtomicThreadFence = checkCDSPassInterfaceFunction(
 315                         M.getOrInsertFunction("cds_atomic_thread_fence", Attr, VoidTy, OrdTy, Int8PtrTy));
 316
 317         MemmoveFn = checkCDSPassInterfaceFunction(
 318                                         M.getOrInsertFunction("memmove", Attr, Int8PtrTy, Int8PtrTy,
 319                                         Int8PtrTy, IntPtrTy));
 320         MemcpyFn = checkCDSPassInterfaceFunction(
 321                                         M.getOrInsertFunction("memcpy", Attr, Int8PtrTy, Int8PtrTy,
 322                                         Int8PtrTy, IntPtrTy));
 323         MemsetFn = checkCDSPassInterfaceFunction(
 324                                         M.getOrInsertFunction("memset", Attr, Int8PtrTy, Int8PtrTy,
 325                                         Int32Ty, IntPtrTy));
 326 }
 327
 328 bool CDSPass::doInitialization(Module &M) {
 329         const DataLayout &DL = M.getDataLayout();
 330         IntPtrTy = DL.getIntPtrType(M.getContext());
 331
 332         // createSanitizerCtorAndInitFunctions is defined in "llvm/Transforms/Utils/ModuleUtils.h"
 333         // We do not support it yet
 334         /*
 335         std::tie(CDSCtorFunction, std::ignore) = createSanitizerCtorAndInitFunctions(
 336                         M, kCDSModuleCtorName, kCDSInitName, {}, {});
 337
 338         appendToGlobalCtors(M, CDSCtorFunction, 0);
 339         */
 340
 341         AtomicFuncNames =
 342         {
 343                 "atomic_init", "atomic_load", "atomic_store",
 344                 "atomic_fetch_", "atomic_exchange", "atomic_compare_exchange_"
 345         };
 346
 347         PartialAtomicFuncNames =
 348         {
 349                 "load", "store", "fetch", "exchange", "compare_exchange_"
 350         };
 351
 352         return true;
 353 }
 354
 355 static bool isVtableAccess(Instruction *I) {
 356         if (MDNode *Tag = I->getMetadata(LLVMContext::MD_tbaa))
 357                 return Tag->isTBAAVtableAccess();
 358         return false;
 359 }
 360
 361 // Do not instrument known races/"benign races" that come from compiler
 362 // instrumentatin. The user has no way of suppressing them.
 363 static bool shouldInstrumentReadWriteFromAddress(const Module *M, Value *Addr) {
 364         // Peel off GEPs and BitCasts.
 365         Addr = Addr->stripInBoundsOffsets();
 366
 367         if (GlobalVariable *GV = dyn_cast<GlobalVariable>(Addr)) {
 368                 if (GV->hasSection()) {
 369                         StringRef SectionName = GV->getSection();
 370                         // Check if the global is in the PGO counters section.
 371                         auto OF = Triple(M->getTargetTriple()).getObjectFormat();
 372                         if (SectionName.endswith(
 373                               getInstrProfSectionName(IPSK_cnts, OF, /*AddSegmentInfo=*/false)))
 374                                 return false;
 375                 }
 376
 377                 // Check if the global is private gcov data.
 378                 if (GV->getName().startswith("__llvm_gcov") ||
 379                 GV->getName().startswith("__llvm_gcda"))
 380                 return false;
 381         }
 382
 383         // Do not instrument acesses from different address spaces; we cannot deal
 384         // with them.
 385         if (Addr) {
 386                 Type *PtrTy = cast<PointerType>(Addr->getType()->getScalarType());
 387                 if (PtrTy->getPointerAddressSpace() != 0)
 388                         return false;
 389         }
 390
 391         return true;
 392 }
 393
 394 bool CDSPass::addrPointsToConstantData(Value *Addr) {
 395         // If this is a GEP, just analyze its pointer operand.
 396         if (GetElementPtrInst *GEP = dyn_cast<GetElementPtrInst>(Addr))
 397                 Addr = GEP->getPointerOperand();
 398
 399         if (GlobalVariable *GV = dyn_cast<GlobalVariable>(Addr)) {
 400                 if (GV->isConstant()) {
 401                         // Reads from constant globals can not race with any writes.
 402                         NumOmittedReadsFromConstantGlobals++;
 403                         return true;
 404                 }
 405         } else if (LoadInst *L = dyn_cast<LoadInst>(Addr)) {
 406                 if (isVtableAccess(L)) {
 407                         // Reads from a vtable pointer can not race with any writes.
 408                         NumOmittedReadsFromVtable++;
 409                         return true;
 410                 }
 411         }
 412         return false;
 413 }
 414
 415 bool CDSPass::shouldInstrumentBeforeAtomics(Instruction * Inst) {
 416         if (LoadInst *LI = dyn_cast<LoadInst>(Inst)) {
 417                 AtomicOrdering ordering = LI->getOrdering();
 418                 if ( isAtLeastOrStrongerThan(ordering, AtomicOrdering::Acquire) )
 419                         return true;
 420         } else if (StoreInst *SI = dyn_cast<StoreInst>(Inst)) {
 421                 AtomicOrdering ordering = SI->getOrdering();
 422                 if ( isAtLeastOrStrongerThan(ordering, AtomicOrdering::Acquire) )
 423                         return true;
 424         } else if (AtomicRMWInst *RMWI = dyn_cast<AtomicRMWInst>(Inst)) {
 425                 AtomicOrdering ordering = RMWI->getOrdering();
 426                 if ( isAtLeastOrStrongerThan(ordering, AtomicOrdering::Acquire) )
 427                         return true;
 428         } else if (AtomicCmpXchgInst *CASI = dyn_cast<AtomicCmpXchgInst>(Inst)) {
 429                 AtomicOrdering ordering = CASI->getSuccessOrdering();
 430                 if ( isAtLeastOrStrongerThan(ordering, AtomicOrdering::Acquire) )
 431                         return true;
 432         } else if (FenceInst *FI = dyn_cast<FenceInst>(Inst)) {
 433                 AtomicOrdering ordering = FI->getOrdering();
 434                 if ( isAtLeastOrStrongerThan(ordering, AtomicOrdering::Acquire) )
 435                         return true;
 436         }
 437
 438         return false;
 439 }
 440
 441 void CDSPass::chooseInstructionsToInstrument(
 442         SmallVectorImpl<Instruction *> &Local, SmallVectorImpl<Instruction *> &All,
 443         const DataLayout &DL) {
 444         SmallPtrSet<Value*, 8> WriteTargets;
 445         // Iterate from the end.
 446         for (Instruction *I : reverse(Local)) {
 447                 if (StoreInst *Store = dyn_cast<StoreInst>(I)) {
 448                         Value *Addr = Store->getPointerOperand();
 449                         if (!shouldInstrumentReadWriteFromAddress(I->getModule(), Addr))
 450                                 continue;
 451                         WriteTargets.insert(Addr);
 452                 } else {
 453                         LoadInst *Load = cast<LoadInst>(I);
 454                         Value *Addr = Load->getPointerOperand();
 455                         if (!shouldInstrumentReadWriteFromAddress(I->getModule(), Addr))
 456                                 continue;
 457                         if (WriteTargets.count(Addr)) {
 458                                 // We will write to this temp, so no reason to analyze the read.
 459                                 NumOmittedReadsBeforeWrite++;
 460                                 continue;
 461                         }
 462                         if (addrPointsToConstantData(Addr)) {
 463                                 // Addr points to some constant data -- it can not race with any writes.
 464                                 continue;
 465                         }
 466                 }
 467                 Value *Addr = isa<StoreInst>(*I)
 468                         ? cast<StoreInst>(I)->getPointerOperand()
 469                         : cast<LoadInst>(I)->getPointerOperand();
 470                 if (isa<AllocaInst>(GetUnderlyingObject(Addr, DL)) &&
 471                                 !PointerMayBeCaptured(Addr, true, true)) {
 472                         // The variable is addressable but not captured, so it cannot be
 473                         // referenced from a different thread and participate in a data race
 474                         // (see llvm/Analysis/CaptureTracking.h for details).
 475                         NumOmittedNonCaptured++;
 476                         continue;
 477                 }
 478                 All.push_back(I);
 479         }
 480         Local.clear();
 481 }
 482
 483 /* Not implemented
 484 void CDSPass::InsertRuntimeIgnores(Function &F) {
 485         IRBuilder<> IRB(F.getEntryBlock().getFirstNonPHI());
 486         IRB.CreateCall(CDSIgnoreBegin);
 487         EscapeEnumerator EE(F, "cds_ignore_cleanup", ClHandleCxxExceptions);
 488         while (IRBuilder<> *AtExit = EE.Next()) {
 489                 AtExit->CreateCall(CDSIgnoreEnd);
 490         }
 491 }*/
 492
 493 bool CDSPass::runOnFunction(Function &F) {
 494         initializeCallbacks( *F.getParent() );
 495         SmallVector<Instruction*, 8> AllLoadsAndStores;
 496         SmallVector<Instruction*, 8> LocalLoadsAndStores;
 497         SmallVector<Instruction*, 8> VolatileLoadsAndStores;
 498         SmallVector<Instruction*, 8> AtomicAccesses;
 499         SmallVector<Instruction*, 8> MemIntrinCalls;
 500
 501         bool Res = false;
 502         bool HasAtomic = false;
 503         bool HasVolatile = false;
 504         const DataLayout &DL = F.getParent()->getDataLayout();
 505
 506         for (auto &BB : F) {
 507                 for (auto &Inst : BB) {
 508                         if ( (&Inst)->isAtomic() ) {
 509                                 AtomicAccesses.push_back(&Inst);
 510                                 HasAtomic = true;
 511
 512                                 if (shouldInstrumentBeforeAtomics(&Inst)) {
 513                                         chooseInstructionsToInstrument(LocalLoadsAndStores, AllLoadsAndStores,
 514                                                 DL);
 515                                 }
 516                         } else if (isAtomicCall(&Inst) ) {
 517                                 AtomicAccesses.push_back(&Inst);
 518                                 HasAtomic = true;
 519                                 chooseInstructionsToInstrument(LocalLoadsAndStores, AllLoadsAndStores,
 520                                         DL);
 521                         } else if (isa<LoadInst>(Inst) || isa<StoreInst>(Inst)) {
 522                                 LoadInst *LI = dyn_cast<LoadInst>(&Inst);
 523                                 StoreInst *SI = dyn_cast<StoreInst>(&Inst);
 524                                 bool isVolatile = ( LI ? LI->isVolatile() : SI->isVolatile() );
 525
 526                                 if (isVolatile) {
 527                                         VolatileLoadsAndStores.push_back(&Inst);
 528                                         HasVolatile = true;
 529                                 } else
 530                                         LocalLoadsAndStores.push_back(&Inst);
 531                         } else if (isa<CallInst>(Inst) || isa<InvokeInst>(Inst)) {
 532                                 if (isa<MemIntrinsic>(Inst))
 533                                         MemIntrinCalls.push_back(&Inst);
 534
 535                                 /*if (CallInst *CI = dyn_cast<CallInst>(&Inst))
 536                                         maybeMarkSanitizerLibraryCallNoBuiltin(CI, TLI);
 537                                 */
 538
 539                                 chooseInstructionsToInstrument(LocalLoadsAndStores, AllLoadsAndStores,
 540                                         DL);
 541                         }
 542                 }
 543
 544                 chooseInstructionsToInstrument(LocalLoadsAndStores, AllLoadsAndStores, DL);
 545         }
 546
 547         for (auto Inst : AllLoadsAndStores) {
 548                 Res |= instrumentLoadOrStore(Inst, DL);
 549         }
 550
 551         for (auto Inst : VolatileLoadsAndStores) {
 552                 Res |= instrumentVolatile(Inst, DL);
 553         }
 554
 555         for (auto Inst : AtomicAccesses) {
 556                 Res |= instrumentAtomic(Inst, DL);
 557         }
 558
 559         for (auto Inst : MemIntrinCalls) {
 560                 Res |= instrumentMemIntrinsic(Inst);
 561         }
 562
 563         // Only instrument functions that contain atomics or volatiles
 564         if (Res && ( HasAtomic || HasVolatile) ) {
 565                 IRBuilder<> IRB(F.getEntryBlock().getFirstNonPHI());
 566                 /* Unused for now
 567                 Value *ReturnAddress = IRB.CreateCall(
 568                         Intrinsic::getDeclaration(F.getParent(), Intrinsic::returnaddress),
 569                         IRB.getInt32(0));
 570                 */
 571
 572                 Value * FuncName = IRB.CreateGlobalStringPtr(F.getName());
 573                 IRB.CreateCall(CDSFuncEntry, FuncName);
 574
 575                 EscapeEnumerator EE(F, "cds_cleanup", true);
 576                 while (IRBuilder<> *AtExit = EE.Next()) {
 577                   AtExit->CreateCall(CDSFuncExit, FuncName);
 578                 }
 579
 580                 Res = true;
 581         }
 582
 583         return false;
 584 }
 585
 586 bool CDSPass::instrumentLoadOrStore(Instruction *I,
 587                                                                         const DataLayout &DL) {
 588         IRBuilder<> IRB(I);
 589         bool IsWrite = isa<StoreInst>(*I);
 590         Value *Addr = IsWrite
 591                 ? cast<StoreInst>(I)->getPointerOperand()
 592                 : cast<LoadInst>(I)->getPointerOperand();
 593
 594         // swifterror memory addresses are mem2reg promoted by instruction selection.
 595         // As such they cannot have regular uses like an instrumentation function and
 596         // it makes no sense to track them as memory.
 597         if (Addr->isSwiftError())
 598                 return false;
 599
 600         int Idx = getMemoryAccessFuncIndex(Addr, DL);
 601         if (Idx < 0)
 602                 return false;
 603
 604         if (IsWrite && isVtableAccess(I)) {
 605                 /* TODO
 606                 LLVM_DEBUG(dbgs() << "  VPTR : " << *I << "\n");
 607                 Value *StoredValue = cast<StoreInst>(I)->getValueOperand();
 608                 // StoredValue may be a vector type if we are storing several vptrs at once.
 609                 // In this case, just take the first element of the vector since this is
 610                 // enough to find vptr races.
 611                 if (isa<VectorType>(StoredValue->getType()))
 612                         StoredValue = IRB.CreateExtractElement(
 613                                         StoredValue, ConstantInt::get(IRB.getInt32Ty(), 0));
 614                 if (StoredValue->getType()->isIntegerTy())
 615                         StoredValue = IRB.CreateIntToPtr(StoredValue, IRB.getInt8PtrTy());
 616                 // Call TsanVptrUpdate.
 617                 IRB.CreateCall(TsanVptrUpdate,
 618                                                 {IRB.CreatePointerCast(Addr, IRB.getInt8PtrTy()),
 619                                                         IRB.CreatePointerCast(StoredValue, IRB.getInt8PtrTy())});
 620                 NumInstrumentedVtableWrites++;
 621                 */
 622                 return true;
 623         }
 624
 625         if (!IsWrite && isVtableAccess(I)) {
 626                 /* TODO
 627                 IRB.CreateCall(TsanVptrLoad,
 628                                                  IRB.CreatePointerCast(Addr, IRB.getInt8PtrTy()));
 629                 NumInstrumentedVtableReads++;
 630                 */
 631                 return true;
 632         }
 633
 634         // TODO: unaligned reads and writes
 635
 636         Value *OnAccessFunc = nullptr;
 637         OnAccessFunc = IsWrite ? CDSStore[Idx] : CDSLoad[Idx];
 638
 639         Type *ArgType = IRB.CreatePointerCast(Addr, Addr->getType())->getType();
 640
 641         if ( ArgType != Int8PtrTy && ArgType != Int16PtrTy &&
 642                         ArgType != Int32PtrTy && ArgType != Int64PtrTy ) {
 643                 // if other types of load or stores are passed in
 644                 return false;
 645         }
 646
 647         IRB.CreateCall(OnAccessFunc, IRB.CreatePointerCast(Addr, Addr->getType()));
 648         if (IsWrite) NumInstrumentedWrites++;
 649         else         NumInstrumentedReads++;
 650         return true;
 651 }
 652
 653 bool CDSPass::instrumentVolatile(Instruction * I, const DataLayout &DL) {
 654         IRBuilder<> IRB(I);
 655         Value *position = getPosition(I, IRB);
 656
 657         if (LoadInst *LI = dyn_cast<LoadInst>(I)) {
 658                 assert( LI->isVolatile() );
 659                 Value *Addr = LI->getPointerOperand();
 660                 int Idx=getMemoryAccessFuncIndex(Addr, DL);
 661                 if (Idx < 0)
 662                         return false;
 663
 664                 Value *args[] = {Addr, position};
 665                 Instruction* funcInst = CallInst::Create(CDSVolatileLoad[Idx], args);
 666                 ReplaceInstWithInst(LI, funcInst);
 667         } else if (StoreInst *SI = dyn_cast<StoreInst>(I)) {
 668                 assert( SI->isVolatile() );
 669                 Value *Addr = SI->getPointerOperand();
 670                 int Idx=getMemoryAccessFuncIndex(Addr, DL);
 671                 if (Idx < 0)
 672                         return false;
 673
 674                 Value *val = SI->getValueOperand();
 675                 Value *args[] = {Addr, val, position};
 676                 Instruction* funcInst = CallInst::Create(CDSVolatileStore[Idx], args);
 677                 ReplaceInstWithInst(SI, funcInst);
 678         } else {
 679                 return false;
 680         }
 681
 682         return true;
 683 }
 684
 685 bool CDSPass::instrumentMemIntrinsic(Instruction *I) {
 686         IRBuilder<> IRB(I);
 687         if (MemSetInst *M = dyn_cast<MemSetInst>(I)) {
 688                 IRB.CreateCall(
 689                         MemsetFn,
 690                         {IRB.CreatePointerCast(M->getArgOperand(0), IRB.getInt8PtrTy()),
 691                          IRB.CreateIntCast(M->getArgOperand(1), IRB.getInt32Ty(), false),
 692                          IRB.CreateIntCast(M->getArgOperand(2), IntPtrTy, false)});
 693                 I->eraseFromParent();
 694         } else if (MemTransferInst *M = dyn_cast<MemTransferInst>(I)) {
 695                 IRB.CreateCall(
 696                         isa<MemCpyInst>(M) ? MemcpyFn : MemmoveFn,
 697                         {IRB.CreatePointerCast(M->getArgOperand(0), IRB.getInt8PtrTy()),
 698                          IRB.CreatePointerCast(M->getArgOperand(1), IRB.getInt8PtrTy()),
 699                          IRB.CreateIntCast(M->getArgOperand(2), IntPtrTy, false)});
 700                 I->eraseFromParent();
 701         }
 702         return false;
 703 }
 704
 705 bool CDSPass::instrumentAtomic(Instruction * I, const DataLayout &DL) {
 706         IRBuilder<> IRB(I);
 707
 708         if (auto *CI = dyn_cast<CallInst>(I)) {
 709                 return instrumentAtomicCall(CI, DL);
 710         }
 711
 712         Value *position = getPosition(I, IRB);
 713
 714         if (LoadInst *LI = dyn_cast<LoadInst>(I)) {
 715                 Value *Addr = LI->getPointerOperand();
 716                 int Idx=getMemoryAccessFuncIndex(Addr, DL);
 717                 if (Idx < 0)
 718                         return false;
 719
 720                 int atomic_order_index = getAtomicOrderIndex(LI->getOrdering());
 721                 Value *order = ConstantInt::get(OrdTy, atomic_order_index);
 722                 Value *args[] = {Addr, order, position};
 723                 Instruction* funcInst = CallInst::Create(CDSAtomicLoad[Idx], args);
 724                 ReplaceInstWithInst(LI, funcInst);
 725         } else if (StoreInst *SI = dyn_cast<StoreInst>(I)) {
 726                 Value *Addr = SI->getPointerOperand();
 727                 int Idx=getMemoryAccessFuncIndex(Addr, DL);
 728                 if (Idx < 0)
 729                         return false;
 730
 731                 int atomic_order_index = getAtomicOrderIndex(SI->getOrdering());
 732                 Value *val = SI->getValueOperand();
 733                 Value *order = ConstantInt::get(OrdTy, atomic_order_index);
 734                 Value *args[] = {Addr, val, order, position};
 735                 Instruction* funcInst = CallInst::Create(CDSAtomicStore[Idx], args);
 736                 ReplaceInstWithInst(SI, funcInst);
 737         } else if (AtomicRMWInst *RMWI = dyn_cast<AtomicRMWInst>(I)) {
 738                 Value *Addr = RMWI->getPointerOperand();
 739                 int Idx=getMemoryAccessFuncIndex(Addr, DL);
 740                 if (Idx < 0)
 741                         return false;
 742
 743                 int atomic_order_index = getAtomicOrderIndex(RMWI->getOrdering());
 744                 Value *val = RMWI->getValOperand();
 745                 Value *order = ConstantInt::get(OrdTy, atomic_order_index);
 746                 Value *args[] = {Addr, val, order, position};
 747                 Instruction* funcInst = CallInst::Create(CDSAtomicRMW[RMWI->getOperation()][Idx], args);
 748                 ReplaceInstWithInst(RMWI, funcInst);
 749         } else if (AtomicCmpXchgInst *CASI = dyn_cast<AtomicCmpXchgInst>(I)) {
 750                 IRBuilder<> IRB(CASI);
 751
 752                 Value *Addr = CASI->getPointerOperand();
 753                 int Idx=getMemoryAccessFuncIndex(Addr, DL);
 754                 if (Idx < 0)
 755                         return false;
 756
 757                 const unsigned ByteSize = 1U << Idx;
 758                 const unsigned BitSize = ByteSize * 8;
 759                 Type *Ty = Type::getIntNTy(IRB.getContext(), BitSize);
 760                 Type *PtrTy = Ty->getPointerTo();
 761
 762                 Value *CmpOperand = IRB.CreateBitOrPointerCast(CASI->getCompareOperand(), Ty);
 763                 Value *NewOperand = IRB.CreateBitOrPointerCast(CASI->getNewValOperand(), Ty);
 764
 765                 int atomic_order_index_succ = getAtomicOrderIndex(CASI->getSuccessOrdering());
 766                 int atomic_order_index_fail = getAtomicOrderIndex(CASI->getFailureOrdering());
 767                 Value *order_succ = ConstantInt::get(OrdTy, atomic_order_index_succ);
 768                 Value *order_fail = ConstantInt::get(OrdTy, atomic_order_index_fail);
 769
 770                 Value *Args[] = {IRB.CreatePointerCast(Addr, PtrTy),
 771                                                  CmpOperand, NewOperand,
 772                                                  order_succ, order_fail, position};
 773
 774                 CallInst *funcInst = IRB.CreateCall(CDSAtomicCAS_V1[Idx], Args);
 775                 Value *Success = IRB.CreateICmpEQ(funcInst, CmpOperand);
 776
 777                 Value *OldVal = funcInst;
 778                 Type *OrigOldValTy = CASI->getNewValOperand()->getType();
 779                 if (Ty != OrigOldValTy) {
 780                         // The value is a pointer, so we need to cast the return value.
 781                         OldVal = IRB.CreateIntToPtr(funcInst, OrigOldValTy);
 782                 }
 783
 784                 Value *Res =
 785                   IRB.CreateInsertValue(UndefValue::get(CASI->getType()), OldVal, 0);
 786                 Res = IRB.CreateInsertValue(Res, Success, 1);
 787
 788                 I->replaceAllUsesWith(Res);
 789                 I->eraseFromParent();
 790         } else if (FenceInst *FI = dyn_cast<FenceInst>(I)) {
 791                 int atomic_order_index = getAtomicOrderIndex(FI->getOrdering());
 792                 Value *order = ConstantInt::get(OrdTy, atomic_order_index);
 793                 Value *Args[] = {order, position};
 794
 795                 CallInst *funcInst = CallInst::Create(CDSAtomicThreadFence, Args);
 796                 ReplaceInstWithInst(FI, funcInst);
 797                 // errs() << "Thread Fences replaced\n";
 798         }
 799         return true;
 800 }
 801
 802 bool CDSPass::isAtomicCall(Instruction *I) {
 803         if ( auto *CI = dyn_cast<CallInst>(I) ) {
 804                 Function *fun = CI->getCalledFunction();
 805                 if (fun == NULL)
 806                         return false;
 807
 808                 StringRef funName = fun->getName();
 809
 810                 // TODO: come up with better rules for function name checking
 811                 for (StringRef name : AtomicFuncNames) {
 812                         if ( funName.contains(name) )
 813                                 return true;
 814                 }
 815
 816                 for (StringRef PartialName : PartialAtomicFuncNames) {
 817                         if (funName.contains(PartialName) &&
 818                                         funName.contains("atomic") )
 819                                 return true;
 820                 }
 821         }
 822
 823         return false;
 824 }
 825
 826 bool CDSPass::instrumentAtomicCall(CallInst *CI, const DataLayout &DL) {
 827         IRBuilder<> IRB(CI);
 828         Function *fun = CI->getCalledFunction();
 829         StringRef funName = fun->getName();
 830         std::vector<Value *> parameters;
 831
 832         User::op_iterator begin = CI->arg_begin();
 833         User::op_iterator end = CI->arg_end();
 834         for (User::op_iterator it = begin; it != end; ++it) {
 835                 Value *param = *it;
 836                 parameters.push_back(param);
 837         }
 838
 839         // obtain source line number of the CallInst
 840         Value *position = getPosition(CI, IRB);
 841
 842         // the pointer to the address is always the first argument
 843         Value *OrigPtr = parameters[0];
 844
 845         int Idx = getMemoryAccessFuncIndex(OrigPtr, DL);
 846         if (Idx < 0)
 847                 return false;
 848
 849         const unsigned ByteSize = 1U << Idx;
 850         const unsigned BitSize = ByteSize * 8;
 851         Type *Ty = Type::getIntNTy(IRB.getContext(), BitSize);
 852         Type *PtrTy = Ty->getPointerTo();
 853
 854         // atomic_init; args = {obj, order}
 855         if (funName.contains("atomic_init")) {
 856                 Value *OrigVal = parameters[1];
 857
 858                 Value *ptr = IRB.CreatePointerCast(OrigPtr, PtrTy);
 859                 Value *val;
 860                 if (OrigVal->getType()->isPtrOrPtrVectorTy())
 861                         val = IRB.CreatePointerCast(OrigVal, Ty);
 862                 else
 863                         val = IRB.CreateIntCast(OrigVal, Ty, true);
 864
 865                 Value *args[] = {ptr, val, position};
 866
 867                 Instruction* funcInst = CallInst::Create(CDSAtomicInit[Idx], args);
 868                 ReplaceInstWithInst(CI, funcInst);
 869
 870                 return true;
 871         }
 872
 873         // atomic_load; args = {obj, order}
 874         if (funName.contains("atomic_load")) {
 875                 bool isExplicit = funName.contains("atomic_load_explicit");
 876
 877                 Value *ptr = IRB.CreatePointerCast(OrigPtr, PtrTy);
 878                 Value *order;
 879                 if (isExplicit)
 880                         order = IRB.CreateBitOrPointerCast(parameters[1], OrdTy);
 881                 else
 882                         order = ConstantInt::get(OrdTy,
 883                                                         (int) AtomicOrderingCABI::seq_cst);
 884                 Value *args[] = {ptr, order, position};
 885
 886                 Instruction* funcInst = CallInst::Create(CDSAtomicLoad[Idx], args);
 887                 ReplaceInstWithInst(CI, funcInst);
 888
 889                 return true;
 890         } else if (funName.contains("atomic") &&
 891                                         funName.contains("load") ) {
 892                 // does this version of call always have an atomic order as an argument?
 893                 Value *ptr = IRB.CreatePointerCast(OrigPtr, PtrTy);
 894                 Value *order = IRB.CreateBitOrPointerCast(parameters[1], OrdTy);
 895                 Value *args[] = {ptr, order, position};
 896
 897                 if (!CI->getType()->isPointerTy()) {
 898                         return false;
 899                 }
 900
 901                 CallInst *funcInst = IRB.CreateCall(CDSAtomicLoad[Idx], args);
 902                 Value *RetVal = IRB.CreateIntToPtr(funcInst, CI->getType());
 903
 904                 CI->replaceAllUsesWith(RetVal);
 905                 CI->eraseFromParent();
 906
 907                 return true;
 908         }
 909
 910         // atomic_store; args = {obj, val, order}
 911         if (funName.contains("atomic_store")) {
 912                 bool isExplicit = funName.contains("atomic_store_explicit");
 913                 Value *OrigVal = parameters[1];
 914
 915                 Value *ptr = IRB.CreatePointerCast(OrigPtr, PtrTy);
 916                 Value *val = IRB.CreatePointerCast(OrigVal, Ty);
 917                 Value *order;
 918                 if (isExplicit)
 919                         order = IRB.CreateBitOrPointerCast(parameters[2], OrdTy);
 920                 else
 921                         order = ConstantInt::get(OrdTy,
 922                                                         (int) AtomicOrderingCABI::seq_cst);
 923                 Value *args[] = {ptr, val, order, position};
 924
 925                 Instruction* funcInst = CallInst::Create(CDSAtomicStore[Idx], args);
 926                 ReplaceInstWithInst(CI, funcInst);
 927
 928                 return true;
 929         } else if (funName.contains("atomic") &&
 930                                         funName.contains("store") ) {
 931                 // Does this version of call always have an atomic order as an argument?
 932                 Value *OrigVal = parameters[1];
 933
 934                 Value *ptr = IRB.CreatePointerCast(OrigPtr, PtrTy);
 935                 Value *val;
 936                 if (OrigVal->getType()->isPtrOrPtrVectorTy())
 937                         val = IRB.CreatePointerCast(OrigVal, Ty);
 938                 else
 939                         val = IRB.CreateIntCast(OrigVal, Ty, true);
 940
 941                 Value *order = IRB.CreateBitOrPointerCast(parameters[2], OrdTy);
 942                 Value *args[] = {ptr, val, order, position};
 943
 944                 Instruction* funcInst = CallInst::Create(CDSAtomicStore[Idx], args);
 945                 ReplaceInstWithInst(CI, funcInst);
 946
 947                 return true;
 948         }
 949
 950         // atomic_fetch_*; args = {obj, val, order}
 951         if (funName.contains("atomic_fetch_") ||
 952                 funName.contains("atomic_exchange")) {
 953
 954                 /* TODO: implement stricter function name checking */
 955                 if (funName.contains("non"))
 956                         return false;
 957
 958                 bool isExplicit = funName.contains("_explicit");
 959                 Value *OrigVal = parameters[1];
 960
 961                 int op;
 962                 if ( funName.contains("_fetch_add") )
 963                         op = AtomicRMWInst::Add;
 964                 else if ( funName.contains("_fetch_sub") )
 965                         op = AtomicRMWInst::Sub;
 966                 else if ( funName.contains("_fetch_and") )
 967                         op = AtomicRMWInst::And;
 968                 else if ( funName.contains("_fetch_or") )
 969                         op = AtomicRMWInst::Or;
 970                 else if ( funName.contains("_fetch_xor") )
 971                         op = AtomicRMWInst::Xor;
 972                 else if ( funName.contains("atomic_exchange") )
 973                         op = AtomicRMWInst::Xchg;
 974                 else {
 975                         errs() << "Unknown atomic read-modify-write operation\n";
 976                         return false;
 977                 }
 978
 979                 Value *ptr = IRB.CreatePointerCast(OrigPtr, PtrTy);
 980                 Value *val;
 981                 if (OrigVal->getType()->isPtrOrPtrVectorTy())
 982                         val = IRB.CreatePointerCast(OrigVal, Ty);
 983                 else
 984                         val = IRB.CreateIntCast(OrigVal, Ty, true);
 985
 986                 Value *order;
 987                 if (isExplicit)
 988                         order = IRB.CreateBitOrPointerCast(parameters[2], OrdTy);
 989                 else
 990                         order = ConstantInt::get(OrdTy,
 991                                                         (int) AtomicOrderingCABI::seq_cst);
 992                 Value *args[] = {ptr, val, order, position};
 993
 994                 Instruction* funcInst = CallInst::Create(CDSAtomicRMW[op][Idx], args);
 995                 ReplaceInstWithInst(CI, funcInst);
 996
 997                 return true;
 998         } else if (funName.contains("fetch")) {
 999                 errs() << "atomic fetch captured. Not implemented yet. ";
1000                 errs() << "See source file :";
1001                 getPosition(CI, IRB, true);
1002                 return false;
1003         } else if (funName.contains("exchange") &&
1004                         !funName.contains("compare_exchange") ) {
1005                 if (CI->getType()->isPointerTy()) {
1006                         /**
1007                          * TODO: instrument the following case
1008                          * mcs-lock.h
1009                          * std::atomic<struct T *> m_tail;
1010                          * struct T * me;
1011                          * struct T * pred = m_tail.exchange(me, memory_order_*);
1012                          */
1013                         errs() << "atomic exchange captured. Not implemented yet. ";
1014                         errs() << "See source file :";
1015                         getPosition(CI, IRB, true);
1016
1017                         return false;
1018                 }
1019
1020                 Value *OrigVal = parameters[1];
1021
1022                 Value *ptr = IRB.CreatePointerCast(OrigPtr, PtrTy);
1023                 Value *val;
1024                 if (OrigVal->getType()->isPtrOrPtrVectorTy())
1025                         val = IRB.CreatePointerCast(OrigVal, Ty);
1026                 else
1027                         val = IRB.CreateIntCast(OrigVal, Ty, true);
1028
1029                 Value *order = IRB.CreateBitOrPointerCast(parameters[2], OrdTy);
1030                 Value *args[] = {ptr, val, order, position};
1031                 int op = AtomicRMWInst::Xchg;
1032
1033                 Instruction* funcInst = CallInst::Create(CDSAtomicRMW[op][Idx], args);
1034                 ReplaceInstWithInst(CI, funcInst);
1035
1036                 return true;
1037         }
1038
1039         /* atomic_compare_exchange_*;
1040            args = {obj, expected, new value, order1, order2}
1041         */
1042         if ( funName.contains("atomic_compare_exchange_") ) {
1043                 bool isExplicit = funName.contains("_explicit");
1044
1045                 Value *Addr = IRB.CreatePointerCast(OrigPtr, PtrTy);
1046                 Value *CmpOperand = IRB.CreatePointerCast(parameters[1], PtrTy);
1047                 Value *NewOperand = IRB.CreateBitOrPointerCast(parameters[2], Ty);
1048
1049                 Value *order_succ, *order_fail;
1050                 if (isExplicit) {
1051                         order_succ = IRB.CreateBitOrPointerCast(parameters[3], OrdTy);
1052
1053                         if (parameters.size() > 4) {
1054                                 order_fail = IRB.CreateBitOrPointerCast(parameters[4], OrdTy);
1055                         } else {
1056                                 /* The failure order is not provided */
1057                                 order_fail = order_succ;
1058                                 ConstantInt * order_succ_cast = dyn_cast<ConstantInt>(order_succ);
1059                                 int index = order_succ_cast->getSExtValue();
1060
1061                                 order_fail = ConstantInt::get(OrdTy,
1062                                                                 AtomicCasFailureOrderIndex(index));
1063                         }
1064                 } else  {
1065                         order_succ = ConstantInt::get(OrdTy,
1066                                                         (int) AtomicOrderingCABI::seq_cst);
1067                         order_fail = ConstantInt::get(OrdTy,
1068                                                         (int) AtomicOrderingCABI::seq_cst);
1069                 }
1070
1071                 Value *args[] = {Addr, CmpOperand, NewOperand,
1072                                                         order_succ, order_fail, position};
1073
1074                 Instruction* funcInst = CallInst::Create(CDSAtomicCAS_V2[Idx], args);
1075                 ReplaceInstWithInst(CI, funcInst);
1076
1077                 return true;
1078         } else if ( funName.contains("compare_exchange_strong") ||
1079                                 funName.contains("compare_exchange_weak") ) {
1080                 Value *Addr = IRB.CreatePointerCast(OrigPtr, PtrTy);
1081                 Value *CmpOperand = IRB.CreatePointerCast(parameters[1], PtrTy);
1082                 Value *NewOperand = IRB.CreateBitOrPointerCast(parameters[2], Ty);
1083
1084                 Value *order_succ, *order_fail;
1085                 order_succ = IRB.CreateBitOrPointerCast(parameters[3], OrdTy);
1086
1087                 if (parameters.size() > 4) {
1088                         order_fail = IRB.CreateBitOrPointerCast(parameters[4], OrdTy);
1089                 } else {
1090                         /* The failure order is not provided */
1091                         order_fail = order_succ;
1092                         ConstantInt * order_succ_cast = dyn_cast<ConstantInt>(order_succ);
1093                         int index = order_succ_cast->getSExtValue();
1094
1095                         order_fail = ConstantInt::get(OrdTy,
1096                                                         AtomicCasFailureOrderIndex(index));
1097                 }
1098
1099                 Value *args[] = {Addr, CmpOperand, NewOperand,
1100                                                         order_succ, order_fail, position};
1101                 Instruction* funcInst = CallInst::Create(CDSAtomicCAS_V2[Idx], args);
1102                 ReplaceInstWithInst(CI, funcInst);
1103
1104                 return true;
1105         }
1106
1107         return false;
1108 }
1109
1110 int CDSPass::getMemoryAccessFuncIndex(Value *Addr,
1111                                                                                 const DataLayout &DL) {
1112         Type *OrigPtrTy = Addr->getType();
1113         Type *OrigTy = cast<PointerType>(OrigPtrTy)->getElementType();
1114         assert(OrigTy->isSized());
1115         uint32_t TypeSize = DL.getTypeStoreSizeInBits(OrigTy);
1116         if (TypeSize != 8  && TypeSize != 16 &&
1117                 TypeSize != 32 && TypeSize != 64 && TypeSize != 128) {
1118                 NumAccessesWithBadSize++;
1119                 // Ignore all unusual sizes.
1120                 return -1;
1121         }
1122         size_t Idx = countTrailingZeros(TypeSize / 8);
1123         //assert(Idx < kNumberOfAccessSizes);
1124         if (Idx >= kNumberOfAccessSizes) {
1125                 return -1;
1126         }
1127         return Idx;
1128 }
1129
1130
1131 char CDSPass::ID = 0;
1132
1133 // Automatically enable the pass.
1134 static void registerCDSPass(const PassManagerBuilder &,
1135                                                         legacy::PassManagerBase &PM) {
1136         PM.add(new CDSPass());
1137 }
1138
1139 /* Enable the pass when opt level is greater than 0 */
1140 static RegisterStandardPasses
1141         RegisterMyPass1(PassManagerBuilder::EP_OptimizerLast,
1142 registerCDSPass);
1143
1144 /* Enable the pass when opt level is 0 */
1145 static RegisterStandardPasses
1146         RegisterMyPass2(PassManagerBuilder::EP_EnabledOnOptLevel0,
1147 registerCDSPass);