The llvm.nvvm.sust.b.2d.v2i64.zero intrinsic; known as __nvvm_sust_b_2d_v2i64_zero in GCC.
See Implementation
The llvm.nvvm.sust.b.2d.v2i64.zero intrinsic; known as __nvvm_sust_b_2d_v2i64_zero in GCC.