Yihong Zhang (张轶泓)

PhD student at Paul G. Allen School of Computer Science & Engineering
yz489 at cs.washington.edu

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About me

I am a fifth-year PhD student studying Computer Science at UW Seattle, co-advised by Zachary Tatlock and Dan Suciu. I am broadly interested in the theories and applications of programming languages and data management.

Currently, I am working on a program optimization technique called Equality Saturation (EqSat):

• Theory: I try to answer questions like "when does EqSat terminate?".
• System: I am working on a new system called egglog that unifies Datalog and EqSat.
• Technique: I am interested in techniques that make EqSat better. In our POPL 2022 paper we made pattern matching in EqSat asymptotically faster.
• Application: I am always looking to apply EqSat to emerging domains, such as computational fabrication. I am maintaining a list of projects that use equality saturation.

I previously interned at Microsoft Gray Systems Lab under Hangdong Zhao, at Adobe Research under Maaz Ahmad and Andrew Adams, at RelationalAI under Martin Bravenboer, and at HKUST under Lionel Parreaux.

Blog  |  Curriculum Vitae  |  Coursework  |  GitHub

Conferences and Workshops

• Vectorizing Recurrences over Semirings Conference
  Yihong Zhang, Bala Vinaithirthan, Karima Ma, Zachary Tatlock, Maaz Ahmad, Andrew Adams
  POPL 2027
  
• Efficient Extraction for Effectful E-Graphs Conference
  Oliver Flatt, Anjali Pal, Yihong Zhang, Ryan Tjoa, Kirsten Graham , Alex Fischman, Chandrakana Nandi, Eli Rosenthal, Zachary Tatlock, Haobin Ni
  OOPSLA 2026
  [arXiv] [acm]
• Rewrite System Showdown: Stochastic Search vs. EqSat
  Qiantan Hong*, Rupanshu Soi*, Yihong Zhang*, Alex Aiken
  EGRAPHS 2026
  [paper]
• Pushing Tensor Accelerators beyond MatMul in a User-Schedulable Language Conference
  Yihong Zhang, Derek Gerstmann, Andrew Adams, Maaz Ahmad
  CGO 2026
  [arXiv] [ieee] [paper] [slides]
• E-Graphs as Circuits, and Optimal Extraction via Treewidth
  Glenn Sun, Yihong Zhang, Haobin Ni 2025
  [arXiv]
• Semantic Foundations of Equality Saturation Conference
  Dan Suciu, Yisu Remy Wang, Yihong Zhang
  ICDT 2025
  [arXiv] [paper] [slides]
• Database Theory in Action: Search-based Program Optimization
  Yihong Zhang, Dan Suciu, Yisu Remy Wang, Max Willsey
  ICDT 2025 Database Theory in Action track
  [paper] [slides]
• Efficient Bottom-Up Synthesis for Programs with Local Variables Conference
  Xiang Li^*, Xiangyu Zhou^*, Rui Dong, Yihong Zhang, Xinyu Wang
  POPL 2024
  Selected for MIT PL Review 2024
  [arXiv]
• Ensuring the Termination of EqSat for Terminating Term Rewriting Systems
  Yihong Zhang, Oliver Flatt
  EGRAPHS@PLDI 2023
  [paper] [slides]
• egglog In Practice: Automatically Improving Floating-point Error
  Oliver Flatt, Yihong Zhang
  EGRAPHS@PLDI 2023
  [paper] [talk]
• Better Together: Unifying Datalog and Equality Saturation Conference
  Yihong Zhang, Yisu Remy Wang, Oliver Flatt, David Cao, Philip Zucker, Eli Rosenthal, Zachary Tatlock, Max Willsey
  PLDI 2023
  Selected for MIT PL Review 2024
  [paper] [slides]
• Chasing an Egg (Contributed Talk)
  Yihong Zhang
  EGRAPHS@PLDI 2022
  [abstract] [slides]
• Relational E-Matching Conference
  Yihong Zhang, Yisu Remy Wang, Max Willsey, Zachary Tatlock
  POPL 2022
  [paper] [talk]
• Faster and Worst-Case Optimal E-Matching via Reduction to Conjunctive Queries
  Yihong Zhang
  PLDI 2021 Student Research Competition (Undergraduate division)
  Won first place at PLDI SRC and second place in the SRC Grand Finals
  [abstract] [poster] [slides] [grand-finals]
• GeCo: Quality Counterfactual Explanations in Real Time Conference
  Maximilian Schleich, Zixuan Geng, Yihong Zhang, Dan Suciu
  VLDB 2021
  [paper] [src] [talk]

Theses

• Towards a Relational E-graph
  Master's Thesis
  Yihong Zhang
  [thesis]

• Faster and Worst-Case Optimal E-Matching
  Undergraduate Honor Thesis
  Yihong Zhang
  [thesis] [slides]