[OpenMP][NFC] Eliminate sign comparison warning via explicit casts

[tianshilei1992]

openmp/libomptarget/plugins/cuda/src/rtl.cpp

232

I'd use C++ cast, aka static_cast<int>(...).

[jdoerfert]

cleanup

[tianshilei1992]

LG

openmp/libomptarget/plugins/cuda/src/rtl.cpp

public:
   // After assignment, the pool becomes the following and s is assigned.
   // xxxxxs+++++++++
   //       ^
   //       id
   CUstream getStream(const int DeviceId) {
     const std::lock_guard<std::mutex> Lock(*StreamMtx[DeviceId]);
     int &Id = NextStreamId[DeviceId];
     // No CUstream left in the pool, we need to request from CUDA RT
-    if (Id == StreamPool[DeviceId].size()) {
+    if (Id == static_cast<int>(StreamPool[DeviceId].size())) {
       // By default we double the stream pool every time
       resizeStreamPool(DeviceId, Id * 2);
     }
     return StreamPool[DeviceId][Id++];
   }
 
   // Return a CUstream back to pool. As mentioned above, per-device next
   // stream is always points to the next available CUstream, so when we return
public:
   }
 
   bool initializeDeviceStreamPool(const int DeviceId) {
     assert(StreamPool[DeviceId].empty() && "stream pool has been initialized");
 
     resizeStreamPool(DeviceId, EnvNumInitialStreams);
 
     // Check the size of stream pool
-    if (StreamPool[DeviceId].size() != EnvNumInitialStreams)
+    if (static_cast<int>(StreamPool[DeviceId].size()) != EnvNumInitialStreams)
       return false;
 
     // Check whether each stream is valid
     for (CUstream &S : StreamPool[DeviceId])
       if (!S)
         return false;
 
     return true;