diff options
Diffstat (limited to 'llvm/lib/Bitcode/Reader/BitcodeReader.cpp')
| -rw-r--r-- | llvm/lib/Bitcode/Reader/BitcodeReader.cpp | 15 |
1 files changed, 13 insertions, 2 deletions
diff --git a/llvm/lib/Bitcode/Reader/BitcodeReader.cpp b/llvm/lib/Bitcode/Reader/BitcodeReader.cpp index cd40857..c13eba7 100644 --- a/llvm/lib/Bitcode/Reader/BitcodeReader.cpp +++ b/llvm/lib/Bitcode/Reader/BitcodeReader.cpp @@ -2923,7 +2923,7 @@ std::error_code BitcodeReader::ParseFunctionBody(Function *F) { } case bitc::FUNC_CODE_INST_CMPXCHG: { // CMPXCHG:[ptrty, ptr, cmp, new, vol, successordering, synchscope, - // failureordering] + // failureordering?, isweak?] unsigned OpNum = 0; Value *Ptr, *Cmp, *New; if (getValueTypePair(Record, OpNum, NextValueNo, Ptr) || @@ -2931,7 +2931,7 @@ std::error_code BitcodeReader::ParseFunctionBody(Function *F) { cast<PointerType>(Ptr->getType())->getElementType(), Cmp) || popValue(Record, OpNum, NextValueNo, cast<PointerType>(Ptr->getType())->getElementType(), New) || - (OpNum + 3 != Record.size() && OpNum + 4 != Record.size())) + (Record.size() < OpNum + 3 || Record.size() > OpNum + 5)) return Error(InvalidRecord); AtomicOrdering SuccessOrdering = GetDecodedOrdering(Record[OpNum+1]); if (SuccessOrdering == NotAtomic || SuccessOrdering == Unordered) @@ -2948,6 +2948,17 @@ std::error_code BitcodeReader::ParseFunctionBody(Function *F) { I = new AtomicCmpXchgInst(Ptr, Cmp, New, SuccessOrdering, FailureOrdering, SynchScope); cast<AtomicCmpXchgInst>(I)->setVolatile(Record[OpNum]); + + if (Record.size() < 8) { + // Before weak cmpxchgs existed, the instruction simply returned the + // value loaded from memory, so bitcode files from that era will be + // expecting the first component of a modern cmpxchg. + CurBB->getInstList().push_back(I); + I = ExtractValueInst::Create(I, 0); + } else { + cast<AtomicCmpXchgInst>(I)->setWeak(Record[OpNum+4]); + } + InstructionList.push_back(I); break; } |