Prakash Murali will present his General Exam "Full-Stack, Real-System Quantum Computer Studies: Noise-Adaptive Compilation, Technology Comparisons and Architectural Insights" on Tuesday, May 21, 2019 at 9am in CS 401. The members of his committee are as follows: Margaret Martonosi (adviser), Kyle Jamieson, and Frederic T. Chong (University of Chicago) Everyone is invited to attend his talk, and those faculty wishing to remain for the oral exam following are welcome to do so. His abstract and reading list follow below. Abstract: In recent years, Quantum Computing (QC) has progressed to the point where small working prototypes are available for use. Termed Noisy Intermediate-Scale Quantum (NISQ) computers, these prototypes are too small for large benchmarks or even for Quantum Error Correction (QEC), but they do have sufficient resources to run small benchmarks, particularly if compiled with optimizations to make use of scarce qubits and limited operation counts and coherence times. First, we observe that current QC prototypes have large spatial and temporal fluctuations in qubit noise and operation error rates. Leveraging this observation, we propose and evaluate noise-adaptive backend compiler approaches to map and optimize high-level QC programs to execute with high reliability on NISQ systems. Using real-system measurements, we show that fine-grained spatial and temporal variations of hardware noise parameters can be exploited to obtain an average 2.9x (and up to 18x) improvement in program success rate over the IBM Qiskit compiler, which is the default compiler on IBM’s quantum systems. Second, we perform a full-stack, benchmark-driven hardware-software analysis of QC systems. We evaluate QC hardware possibilities (qubit types, connectivity, noise), software-visible gates (ISA), and software optimizations to tackle fundamental design choices for the execution stack. To enable our study, we built TriQ, the first top-to-bottom toolflow to target different qubit device technologies, including superconducting and trapped ion qubits which are the current QC front-runners. We use TriQ to conduct real-system measurements on 6 QC systems from three different groups, IBM, Rigetti, and University of Maryland. We draw conclusions about gate set design, factors affecting program performance and compiler optimizations to mitigate hardware limitations. We demonstrate that leveraging microarchitecture details in the compiler improves program success rate up to 28x on IBM (geomean 3x), 2.3x on Rigetti (geomean 1.4x), and 1.47x on UMD (geomean 1.17x), compared to respective vendor toolflows. Reading List Muhamamd Ahsan, Byung-Soo Choi, Jungsang Kim. Performance simulator based on hardware resources constraints for ion trap quantum computer. IEEE International Conference on Computer Design (ICCD) 2013 David P. DiVincenzo. The Physical Implementation of Quantum Computation. Fortschritte der Physik 48, p. 771 (2000) arXiv:quant-ph/0002077 Richard Feynman. Simulating physics with computers. International Journal of Theoretical Physics, Vol 21, Nos. 6/7, 1982. X. Fu, M. A. Rol, C. C. Bultink, J. van Someren, N. Khammassi, I. Ashraf, R. F. L. Vermeulen, J. C. de Sterke, W. J. Vlothuizen, R. N. Schouten, C. G. Almudever, L. DiCarlo, K. Bertels. An Experimental Microarchitecture for a Superconducting Quantum Processor. MICRO-50 (2017) Lov Grover. A fast quantum mechanical algorithm for database search. ACM Symposium on the Theory of Computing (STOC) 1996. Ali Javadi-Abhari, Pranav Gokhale, Adam Holmes, Diana Franklin, Ken Brown, Margaret Martonosi, and Frederic T. Chong. Optimized Surface Code Communication in Superconducting Quantum Computers, International Symposium on Microarchitecture, 2017 Ali Javadi-Abhari, Shruti Patil, Daniel Kudrow, Jeff Heckey, Alexey Lvov, Frederic T. Chong, Margaret Martonosi. ScaffCC: A Framework for Compilation and Analysis of Quantum Computing Programs. ACM International Conference on Computing Frontiers, May 2014. Jeff Heckey, Shruti Patil, Ali Javadi-Abhari, Adam Holmes, Daniel Kudrow, Ken Brown, Diana Franklin, Margaret Martonosi, Frederic T. Chong. Compiler Management of Communication and Parallelism for Quantum Computation. Architectural Support for Programming Languages and Operating Systems (ASPLOS), 2015. Norbert M. Linke, Dmitri Maslov, Martin Roetteler, Shantanu Debnath, Caroline Figgatt, Kevin A. Landsman, Kenneth Wright, and Christopher Monroe. Experimental comparison of two quantum computing architectures. PNAS 114, 3305-3310 (2017) Tony Nowatzki, Michael Sartin-Tarm, Lorenzo De Carli, Karthikeyan Sankaralingam, Cristian Estan, Behnam Robatmili.. A general constraint-centric scheduling framework for spatial architectures. PLDI 2013: 495-506 Marcos Yukio Siraichi, Vinícius Fernandes dos Santos, Sylvain Collange, Fernando Magno Quintao Pereira. Qubit allocation. International Symposium on Code Generation and Optimization (CGO) 2018 Krysta M. Svore, Igor L. Markov, Isaac Chuang, Andrew W. Cross, Alfred V. Aho. A Layered Software Architecture for Quantum Computing Design Tools. IEEE Computer (Volume: 39, Issue: 1, Jan. 2006) Textbook: John L. Hennessy and David A. Patterson. Computer Architecture: A Quantitative Approach. Morgan Kaufmann 5th edition (2011).