TY - GEN
T1 - Y-branches
T2 - 12th International Conference on Parallel Architectures and Compilation Techniques, PACT 2003
AU - Wang, N.
AU - Fertig, M.
AU - Patel, Sanjay
N1 - Funding Information:
We thank the other members of the Advanced Computing Systems group as well as Steve Lumetta, Scott Mahlke, and the anonymous referees for providing feedback during various stages of this work. This material is based upon work supported by the National Science Foundation under Grant No. 00092740 and the C2S2 Marco Center, with support from AMD, Intel, and Sun Microsystems.
Publisher Copyright:
© 2003 IEEE.
PY - 2003
Y1 - 2003
N2 - We study the effects of manipulating the architected direction of conditional branches. Through the use of statistical sampling, we find that about 40% of all dynamic branches and about 50% of mispredicted branches do not affect correct program behavior when forced down the incorrect path. We call such branches Y-branches. To further examine this unexpected phenomenon, we provide a characterization of the coding constructs that give rise to such branches. Examples of such coding constructs include short-circuits and ineffectual loop iterations. We provide a statistical breakdown of the frequency of these branches and their constructs. Finally, we suggest some techniques for exploiting this behavior, particularly when it results from short-circuit constructs.
AB - We study the effects of manipulating the architected direction of conditional branches. Through the use of statistical sampling, we find that about 40% of all dynamic branches and about 50% of mispredicted branches do not affect correct program behavior when forced down the incorrect path. We call such branches Y-branches. To further examine this unexpected phenomenon, we provide a characterization of the coding constructs that give rise to such branches. Examples of such coding constructs include short-circuits and ineffectual loop iterations. We provide a statistical breakdown of the frequency of these branches and their constructs. Finally, we suggest some techniques for exploiting this behavior, particularly when it results from short-circuit constructs.
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U2 - 10.1109/PACT.2003.1238002
DO - 10.1109/PACT.2003.1238002
M3 - Conference contribution
AN - SCOPUS:84968854658
T3 - Parallel Architectures and Compilation Techniques - Conference Proceedings, PACT
SP - 56
EP - 66
BT - Proceedings - 12th International Conference on Parallel Architectures and Compilation Techniques, PACT 2003
PB - Institute of Electrical and Electronics Engineers Inc.
Y2 - 27 September 2003 through 1 October 2003
ER -