Just some random thoughts:
I just tried to build PyTorch on the recently released CUDA 9.2, and had some weird compiler error, such as:
/usr/local/cuda-9.2/include/cuda_fp16.hpp(299): error: no operator "&&" matches these operands
            operand types are: __half && __half
                                                                                                                       
/usr/local/cuda-9.2/include/cuda_fp16.hpp(300): error: no operator "&&" matches these operands
            operand types are: __half && __half
                                                                                                                       
/usr/local/cuda-9.2/include/cuda_fp16.hpp(301): error: no operator "&&" matches these operands
            operand types are: __half && __half
                                                                                                                       
/usr/local/cuda-9.2/include/cuda_fp16.hpp(302): error: no operator "&&" matches these operands
            operand types are: __half && __half
                                                                                                                       
/usr/local/cuda-9.2/include/cuda_fp16.hpp(303): error: no operator "&&" matches these operands
            operand types are: __half && __half
                                                                                                                       
/usr/local/cuda-9.2/include/cuda_fp16.hpp(304): error: no operator "&&" matches these operands
            operand types are: __half && __half
                                                                                                                       
6 errors detected in the compilation of "/tmp/tmpxft_000040bf_00000000-6_THCReduceApplyUtils.cpp1.ii".
CMake Error at ATen_cuda_generated_THCReduceApplyUtils.cu.o.Release.cmake:279 (message):
  Error generating file
  /.../aten/build/src/ATen/CMakeFiles/ATen_cuda.dir/__/THC/./ATen_cuda_generated_THCReduceApplyUtils.cu.o

After some tinkering, I found that the build succeeds if I add __CUDA_NO_HALF2_OPERATORS__:
diff --git a/aten/CMakeLists.txt b/aten/CMakeLists.txt
index bdf3145..7620d23 100644
--- a/aten/CMakeLists.txt
+++ b/aten/CMakeLists.txt
@@ -165,7 +165,7 @@ ENDIF()
 
 IF(CUDA_HAS_FP16 OR NOT ${CUDA_VERSION} LESS 7.5)
   MESSAGE(STATUS "Found CUDA with FP16 support, compiling with torch.CudaHalfTensor")
-  LIST(APPEND CUDA_NVCC_FLAGS "-DCUDA_HAS_FP16=1 -D__CUDA_NO_HALF_OPERATORS__ -D__CUDA_NO_HALF_CONVERSIONS__")
+  LIST(APPEND CUDA_NVCC_FLAGS "-DCUDA_HAS_FP16=1 -D__CUDA_NO_HALF_OPERATORS__ -D__CUDA_NO_HALF_CONVERSIONS__ -D__CUDA_NO_HALF2_OPERATORS__")
   add_compile_options(-DCUDA_HAS_FP16=1)
 ELSE(CUDA_HAS_FP16 OR NOT ${CUDA_VERSION} LESS 7.5)
   MESSAGE(STATUS "Could not find CUDA with FP16 support, compiling without torch.CudaHalfTensor")

I don’t know if it applies to others, but if anybody’s trying to build with CUDA 9.2 and having problems, this might help.

BTW, I didn’t know 9.2 was released three days ago! No wonder I had a problem with the build…