An Instruction Set Architecture for Lattice Surgery Computers

We describe an open source instruction set architecture (ISA) of a quantum computer that uses lattice surgery for executing quantum error-corrected computations. Our ISA is built on top of the typical operations supported by QLDPC codes, and is shifting the focus from quantum gates and multibody measurements to instructions. A well designed ISA is very useful for writing more efficient compilers for optimized and functionally correct computations. Our ISA is a small, optimized set of instructions for performing I/O, memory, distillation, measurement, reversible logic and feed forward. We illustrate the functionality of the ISA on the example of different designs of processing units, and we automatically compile quantum computations to this ISA to showcase its optimization capabilities.