Complexity-effective superscalar processors
Proceedings of the 24th annual international symposium on Computer architecture
Proceedings of the 14th international conference on Supercomputing
On pipelining dynamic instruction scheduling logic
Proceedings of the 33rd annual ACM/IEEE international symposium on Microarchitecture
A circuit level implementation of an adaptive issue queue for power-aware microprocessors
GLSVLSI '01 Proceedings of the 11th Great Lakes symposium on VLSI
Reducing the complexity of the issue logic
ICS '01 Proceedings of the 15th international conference on Supercomputing
ISCA '01 Proceedings of the 28th annual international symposium on Computer architecture
Efficient dynamic scheduling through tag elimination
ISCA '02 Proceedings of the 29th annual international symposium on Computer architecture
A large, fast instruction window for tolerating cache misses
ISCA '02 Proceedings of the 29th annual international symposium on Computer architecture
A scalable instruction queue design using dependence chains
ISCA '02 Proceedings of the 29th annual international symposium on Computer architecture
Proceedings of the 34th annual ACM/IEEE international symposium on Microarchitecture
Select-free instruction scheduling logic
Proceedings of the 34th annual ACM/IEEE international symposium on Microarchitecture
Energy-efficient hybrid wakeup logic
Proceedings of the 2002 international symposium on Low power electronics and design
Hierarchical Scheduling Windows
Proceedings of the 35th annual ACM/IEEE international symposium on Microarchitecture
Proceedings of the 30th annual international symposium on Computer architecture
Energy efficient co-adaptive instruction fetch and issue
Proceedings of the 30th annual international symposium on Computer architecture
Cyclone: a broadcast-free dynamic instruction scheduler with selective replay
Proceedings of the 30th annual international symposium on Computer architecture
Data-Flow Prescheduling for Large Instruction Windows in Out-of-Order Processors
HPCA '01 Proceedings of the 7th International Symposium on High-Performance Computer Architecture
Macro-op Scheduling: Relaxing Scheduling Loop Constraints
Proceedings of the 36th annual IEEE/ACM International Symposium on Microarchitecture
Energy-efficient issue queue design
IEEE Transactions on Very Large Scale Integration (VLSI) Systems - Special section on low power
Energy Efficient Comparators for Superscalar Datapaths
IEEE Transactions on Computers
Scaling the issue window with look-ahead latency prediction
Proceedings of the 18th annual international conference on Supercomputing
Wire Delay is Not a Problem for SMT (In the Near Future)
Proceedings of the 31st annual international symposium on Computer architecture
ASPLOS XI Proceedings of the 11th international conference on Architectural support for programming languages and operating systems
Dataflow Mini-Graphs: Amplifying Superscalar Capacity and Bandwidth
Proceedings of the 37th annual IEEE/ACM International Symposium on Microarchitecture
Out-of-Order Commit Processors
HPCA '04 Proceedings of the 10th International Symposium on High Performance Computer Architecture
Low-Complexity Distributed Issue Queue
HPCA '04 Proceedings of the 10th International Symposium on High Performance Computer Architecture
Reducing the Scheduling Critical Cycle Using Wakeup Prediction
HPCA '04 Proceedings of the 10th International Symposium on High Performance Computer Architecture
Exploring Wakeup-Free Instruction Scheduling
HPCA '04 Proceedings of the 10th International Symposium on High Performance Computer Architecture
Exploiting Operand Availability for Efficient Simultaneous Multithreading
IEEE Transactions on Computers
Process variation aware issue queue design
Proceedings of the conference on Design, automation and test in Europe
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Dynamic instruction scheduling logic is one of the most critical components of modern superscalar microprocessors, both from the delay and power dissipation standpoints. The delay and energy requirement of driving the result tags across the associatively-addressed issue queue accounts for a significant percentage of the scheduler's overhead and also limits the design scalability. We propose two schemes to reduce the power consumption and the delays of the wakeup logic. Our first scheme – instruction packing – shares the associative part of an issue queue entry between two instructions, each with at most one non-ready source. As a result, the number of entries in the issue queue (and, hence, the length of the tag buses) can be reduced by a factor of two with almost no impact on the IPCs, because most instructions either enter the pipeline with at least one of their source operands ready, or do not make use of two source registers to begin with. Our second scheme – tag memoization – avoids driving the upper portion of the tags, if those bits did not change their values from what was driven on the same tag bus during the most recent broadcast. While instruction packing results in the reduced length of the tag buses, tag memoization reduced the number of tag lines that need to be driven. We evaluate our designs using detailed microarchitectural simulations of the SPEC 2000 benchmarks and the SPICE simulations of the issue queue layouts.