Fixed error when using Nvidia GPU on Apple's OpenCL

platforms/opencl/src/OpenCLContext.cpp

@@ -98,7 +98,7 @@ OpenCLContext::OpenCLContext(int numParticles, int deviceIndex, OpenCLPlatform::
         if (vendor.size() >= 6 && vendor.substr(0, 6) == "NVIDIA") {
             compilationOptions += " -DWARPS_ARE_ATOMIC";
             simdWidth = 32;
-
+            if (device.getInfo<CL_DEVICE_EXTENSIONS>().find("cl_nv_device_attribute_query") != string::npos) {
                 // Compute level 1.2 and later Nvidia GPUs support 64 bit atomics, even though they don't list the
                 // proper extension as supported.
 
@@ -108,6 +108,7 @@ OpenCLContext::OpenCLContext(int numParticles, int deviceIndex, OpenCLPlatform::
                 if (computeCapabilityMajor > 1 || computeCapabilityMinor > 1)
                     supports64BitGlobalAtomics = true;
             }
+        }
         else if (vendor.size() >= 28 && vendor.substr(0, 28) == "Advanced Micro Devices, Inc.") {
             // AMD APP SDK 2.4 has a performance problem with atomics. Enable the work around.
             compilationOptions += " -DAMD_ATOMIC_WORK_AROUND";