Method compileAtomicCompareExchange

lib/llvm/compiler.cpp:4134–4165

    }
  }
  void compileAtomicCompareExchange(unsigned MemoryIndex, uint64_t MemoryOffset,
                                    [[maybe_unused]] unsigned Alignment,
                                    LLVM::Type IntType, LLVM::Type TargetType,
                                    bool Signed = false) noexcept {

    auto Replacement = Builder.createSExtOrTrunc(stackPop(), TargetType);
    auto Expected = Builder.createSExtOrTrunc(stackPop(), TargetType);
    auto Offset = Builder.createZExt(Stack.back(), Context.Int64Ty);
    if (MemoryOffset != 0) {
      Offset = Builder.createAdd(Offset, LLContext.getInt64(MemoryOffset));
    }
    compileAtomicCheckOffsetAlignment(Offset, TargetType);
    auto VPtr = Builder.createInBoundsGEP1(
        Context.Int8Ty, Context.getMemory(Builder, ExecCtx, MemoryIndex),
        Offset);
    auto Ptr = Builder.createBitCast(VPtr, TargetType.getPointerTo());

    auto Ret = Builder.createAtomicCmpXchg(
        Ptr, switchEndian(Expected), switchEndian(Replacement),
        LLVMAtomicOrderingSequentiallyConsistent,
        LLVMAtomicOrderingSequentiallyConsistent);
#if LLVM_VERSION_MAJOR >= 13
    Ret.setAlignment(1 << Alignment);
#endif
    auto OldVal = Builder.createExtractValue(Ret, 0);
    OldVal = switchEndian(OldVal);
    if (Signed) {
      Stack.back() = Builder.createSExt(OldVal, IntType);
    } else {
      Stack.back() = Builder.createZExt(OldVal, IntType);
    }
  }

  void compileReturn() noexcept {
    updateInstrCount();