[llvm-commits] [llvm] r73628 - /llvm/trunk/lib/VMCore/Constants.cpp

[Bill Wendling]

On Wed, Jun 17, 2009 at 1:10 PM, Owen Anderson<resistor at mac.com> wrote:

> --- llvm/trunk/lib/VMCore/Constants.cpp (original)
> +++ llvm/trunk/lib/VMCore/Constants.cpp Wed Jun 17 15:10:08 2009

> @@ -1225,37 +1229,85 @@
>     /// necessary.
>     ConstantClass *getOrCreate(const TypeClass *Ty, const ValType &V) {
>       MapKey Lookup(Ty, V);
> -      typename MapTy::iterator I = Map.find(Lookup);
> -      // Is it in the map?
> -      if (I != Map.end())
> -        return static_cast<ConstantClass *>(I->second);
> -
> -      // If no preexisting value, create one now...
> -      ConstantClass *Result =
> -        ConstantCreator<ConstantClass,TypeClass,ValType>::create(Ty, V);
> -
> -      assert(Result->getType() == Ty && "Type specified is not correct!");
> -      I = Map.insert(I, std::make_pair(MapKey(Ty, V), Result));
> -
> -      if (HasLargeKey)  // Remember the reverse mapping if needed.
> -        InverseMap.insert(std::make_pair(Result, I));
> -
> -      // If the type of the constant is abstract, make sure that an entry exists
> -      // for it in the AbstractTypeMap.
> -      if (Ty->isAbstract()) {
> -        typename AbstractTypeMapTy::iterator TI = AbstractTypeMap.find(Ty);
> -
> -        if (TI == AbstractTypeMap.end()) {
> -          // Add ourselves to the ATU list of the type.
> -          cast<DerivedType>(Ty)->addAbstractTypeUser(this);
> -
> -          AbstractTypeMap.insert(TI, std::make_pair(Ty, I));
> +      if (llvm_is_multithreaded()) {
> +        ConstantClass* Result = 0;
> +
> +        ConstantsLock->reader_acquire();
> +        typename MapTy::iterator I = Map.find(Lookup);
> +        // Is it in the map?
> +        if (I != Map.end())
> +          Result = static_cast<ConstantClass *>(I->second);
> +        ConstantsLock->reader_release();
> +
> +        if (!Result) {
> +          ConstantsLock->writer_acquire();
> +          I = Map.find(Lookup);
> +          // Is it in the map?
> +          if (I != Map.end())
> +            Result = static_cast<ConstantClass *>(I->second);
> +          if (!Result) {
> +            // If no preexisting value, create one now...
> +            Result =
> +              ConstantCreator<ConstantClass,TypeClass,ValType>::create(Ty, V);
> +
> +            assert(Result->getType() == Ty && "Type specified is not correct!");
> +            I = Map.insert(I, std::make_pair(MapKey(Ty, V), Result));
> +
> +            if (HasLargeKey)  // Remember the reverse mapping if needed.
> +              InverseMap.insert(std::make_pair(Result, I));
> +
> +            // If the type of the constant is abstract, make sure that an entry
> +            // exists for it in the AbstractTypeMap.
> +            if (Ty->isAbstract()) {
> +              typename AbstractTypeMapTy::iterator TI =
> +                                                       AbstractTypeMap.find(Ty);
> +
> +              if (TI == AbstractTypeMap.end()) {
> +                // Add ourselves to the ATU list of the type.
> +                cast<DerivedType>(Ty)->addAbstractTypeUser(this);
> +
> +                AbstractTypeMap.insert(TI, std::make_pair(Ty, I));
> +              }
> +            }
> +          }
> +          ConstantsLock->writer_release();
>         }

Owen,

Could you revisit and rework this so that so much code isn't copied in
the if-then-else statement?

-bw