Dynamic local and remote order #2461
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Something is broken with scala.collection.mutable.HashMap. Insertions get slower and slower as the map gets more full. groupBy is more idiomatic anyway.
No longer exponential time!
The perfect implementation of this algorithm would be to perform a full circuit minimization, ala Quine–McCluskey. However, that would require expanding out to every addres, very exponential time! The previous heuristic algorithm was O(n^2) for n AddressSet terms. However, it did not always merge sets by the same bit in order. This led to poor outcomes on common inputs. The new heuristic merges by lowest bits first. This is O(n * bits), which has better worst-case performance. On contiguous ranges it also finds better results.
The remote/local routing decision is too granular to leave to a static FIFOFixer. If you have 1MiB of local memory in a 256MiB region, you had to describe 256 different FIFO regions, one for each potential offset of the local memory. There are actually only two options: local or remote. Use the dynamic routing information of the AddressAdjuster.
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hcook
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May 13, 2020
hcook
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May 13, 2020
hcook
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May 13, 2020
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Type of change: bug report
Impact: no functional change
Development Phase: implementation
Release Notes
Improved QoR in designs with large physical address maps.