[SYCL][HIP] Use valid cast for CUdeviceptr in HIP PI (#6207)

Replace invalid reinterpret_cast with static_cast
for CUdeviceptr in hip_piextMemGetNativeHandle
when building HIP PI on CUDA machine;

Signed-off-by: Lukas Sommer <[email protected]>

Author: sommerlukas

sycl/plugins/hip/pi_hip.cpp

@@ -2132,8 +2132,27 @@ pi_result hip_piMemGetInfo(pi_mem memObj, pi_mem_info queriedInfo,
 /// \return PI_SUCCESS
 pi_result hip_piextMemGetNativeHandle(pi_mem mem,
                                       pi_native_handle *nativeHandle) {
+#if defined(__HIP_PLATFORM_NVIDIA__)
+  if (sizeof(_pi_mem::mem_::buffer_mem_::native_type) >
+      sizeof(pi_native_handle)) {
+    // Check that all the upper bits that cannot be represented by
+    // pi_native_handle are empty.
+    // NOTE: The following shift might trigger a warning, but the check in the
+    // if above makes sure that this does not underflow.
+    _pi_mem::mem_::buffer_mem_::native_type upperBits =
+        mem->mem_.buffer_mem_.get() >> (sizeof(pi_native_handle) * CHAR_BIT);
+    if (upperBits) {
+      // Return an error if any of the remaining bits is non-zero.
+      return PI_INVALID_MEM_OBJECT;
+    }
+  }
+  *nativeHandle = static_cast<pi_native_handle>(mem->mem_.buffer_mem_.get());
+#elif defined(__HIP_PLATFORM_AMD__)
   *nativeHandle =
       reinterpret_cast<pi_native_handle>(mem->mem_.buffer_mem_.get());
+#else
+#error("Must define exactly one of __HIP_PLATFORM_AMD__ or __HIP_PLATFORM_NVIDIA__");
+#endif
   return PI_SUCCESS;
 }