The IMPACT Research Group
University of Illinois at Urbana-Champaign


The objective of IMPACT (Illinois Microarchitecture Project utilizing Advanced Compiler Technology) is to provide critical research, architecture expertise, and compiler prototypes for the microprocessor industry. This objective is accomplished by analyzing and demonstrating the level of hardware and compiler support required by architectural enhancements in order to understand the cost and effectiveness of these enhancements. IMPACT's primary focus is on exposing, enhancing, and exploiting instruction-level parallelism (ILP).

The IMPACT compiler framework was created by the IMPACT research group under the direction of Professor Wen-mei W. Hwu. The IMPACT research group is affiliated with the Center for Reliable and High-Performance Computing which is part of the Coordinated Science Laboratory, an interdisciplinary research organization at the University of Illinois at Urbana-Champaign. Wen-mei Hwu is a Professor at the Department of Electrical and Computer Engineering. Graduate students from the IMPACT research group are from either the Department of Electrical and Computer Engineering or the Department of Computer Science. Details about IMPACT team members, past and present, who developed this framework can be found at the IMPACT web page,


The IMPACT public and Trimaran release effort (versions 1.00-2.33) was lead by Professor John Gyllenhaal. He would like to thank Professor Wen-mei W. Hwu for encouraging and supporting this release effort; Brian Deitrich and Daniel Lavery for leading and coordinating the IMPACT beta releases prior to May 1997; John Sias, Ben-Chung Cheng, Dan Connors, Scott Mahlke, David August, Liesl Little, Matthew Merten, Andy Trick, Patrick Eaton, Rick Hank, Le-Chun Wu, Qudus Olaniran, Sabrina Hwu, and Jason Fritts for their extensive help in making these releases stable and for graciously acting as sounding boards even when they were extremely busy with their own research; and the IMPACT compiler team in general for all of their contributions, help, and support. He would also like to thank all the Trimaran council members, especially Vinod Kathail, Ralph Hyver, Tom Christian and Han-Soo Kim, and the entire Trimaran team, especially Rodric Rabbah, for their efforts to make the Trimaran release a success.

Brian Deitrich, Daniel Lavery, and John Gyllenhaal would also like to thank the IMPACT public release beta testers for all their feedback.

The IMPACT research group thanks the National Science Foundation (NSF) for supporting a significant portion of this release effort under grant CCR-9809404.

The IMPACT compiler framework is the result of numerous research efforts by 45+ graduate students over the last ten years. These research efforts were supported by the National Science Foundation (NSF) under grants CCR-9809478, CCR-9629948, MIP-930813, and MIP-8809478, Hewlett-Packard, Intel Corporation, Advanced Micro Devices, Microsoft, SUN Microsystems, NCR, Mazda Motor Corporation, Matsushita Electric Industrial Corporation, Joint Services Engineering Programs (JSEP) under contract N00014-90-J-1270, and the National Aeronautics and Space Administration (NASA) under Contract NASA NAG 1-613 in cooperation with the Illinois Computer Laboratory for Aerospace Systems and Software (ICLASS).

The IMPACT compiler's C front end is built upon the Edison Design Group's C/C++ front end (see EDG_CTOP_LICENSE).

IMPACT's predicate analysis makes extensive use of the CUDD-2.2.0 package developed at the University of Colorado at Boulder by Fabio Somenzi.

The IMPACT compiler framework relies on the portable Lcode (IMPACT's IR) emulator, platform info framework, and the portability enhancements developed by IMPACT Technologies, Inc. (see ITI_LICENSE) to allow IMPACT's and Trimaran's IR to be emulated on a wide variety of platforms.