Efficiently computing static single assignment form and the control dependence graph
ACM Transactions on Programming Languages and Systems (TOPLAS)
PACT '95 Proceedings of the IFIP WG10.3 working conference on Parallel architectures and compilation techniques
A comparison of full and partial predicated execution support for ILP processors
ISCA '95 Proceedings of the 22nd annual international symposium on Computer architecture
Assigning confidence to conditional branch predictions
Proceedings of the 29th annual ACM/IEEE international symposium on Microarchitecture
A framework for balancing control flow and predication
MICRO 30 Proceedings of the 30th annual ACM/IEEE international symposium on Microarchitecture
Conversion of control dependence to data dependence
POPL '83 Proceedings of the 10th ACM SIGACT-SIGPLAN symposium on Principles of programming languages
Microarchitectural exploration with Liberty
Proceedings of the 35th annual ACM/IEEE international symposium on Microarchitecture
Predicate prediction for efficient out-of-order execution
ICS '03 Proceedings of the 17th annual international conference on Supercomputing
Register Renaming and Scheduling for Dynamic Execution of Predicated Code
HPCA '01 Proceedings of the 7th International Symposium on High-Performance Computer Architecture
Pinpointing Representative Portions of Large Intel® Itanium® Programs with Dynamic Instrumentation
Proceedings of the 37th annual IEEE/ACM International Symposium on Microarchitecture
Wish Branches: Combining Conditional Branching and Predication for Adaptive Predicated Execution
Proceedings of the 38th annual IEEE/ACM International Symposium on Microarchitecture
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If-conversion transforms control dependencies to data dependencies by using a predication mechanism. It is useful to eliminate hard-to-predict branches and to reduce the severe performance impact of branch mispredictions. However, the use of predicated execution in out-of-order processors has to deal with two problems: there can be multiple definitions for a single destination register at rename time, and instructions with a false predicated consume unnecessary resources. Predicting predicates is an effective approach to address both problems. However, predicting predicates that come from hard-to-predict branches is not beneficial in general, because this approach reverses the if-conversion transformation, loosing its potential benefits. In this paper we propose a new scheme that dynamically selects which predicates are worthy to be predicted, and which one are more effective in its if-converted form. We show that our approach significantly outperforms previous proposed schemes. Moreover it performs within 5% of an ideal scheme with perfect predicate prediction.