llvm/libclc/generic/include/clc/explicit_fence/explicit_memory_fence.h

_CLC_DECL _CLC_OVERLOAD void mem_fence(cl_mem_fence_flags flags);
_CLC_DECL _CLC_OVERLOAD void read_mem_fence(cl_mem_fence_flags flags);
_CLC_DECL _CLC_OVERLOAD void write_mem_fence(cl_mem_fence_flags flags);