Fix csr cycle unasync #630
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Max042004
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Benchmarks
| Benchmark suite | Current: f69568a | Previous: 1e5e3f8 | Ratio |
|---|---|---|---|
Dhrystone |
1318 Average DMIPS over 10 runs |
1303 Average DMIPS over 10 runs |
0.99 |
Coremark |
914.12 Average iterations/sec over 10 runs |
916.441 Average iterations/sec over 10 runs |
1.00 |
This comment was automatically generated by workflow using github-action-benchmark.
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Enforce the rules specified in https://cbea.ms/git-commit/ carefully.
Previous commit 78836cf prevents frequently update of rv->csr_cycle by manipulate it with register. However, currently rv->csr_cycle only update after a block end or JIT clearing block map. This results csr cycle instructions cannot fetch up-to-date cycle. If started cycle and ended cycle are located in a same block, it cause the cycle count becomes zero. This commit updates rv->csr_cycle before csr cycle instruction is executed.
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Previous commit 78836cf prevents frequently update of rv->csr_cycle by manipulate it with register. However, currently rv->csr_cycle only update after a block end or JIT clearing block map. This results csr cycle instructions cannot fetch up-to-date cycle. If csr cycle instructions are located in a same block, leading to the result cycle count becomes zero.
This commit updates rv->csr_cycle everytime before csr instruction is executed.
Summary by cubic
Synchronizes cycle and instret CSR reads by updating rv->csr_cycle right before those CSRs execute, so they return the current value even within the same block. Fixes cases where these CSRs could read zero or stale counts until block end.
Written for commit f69568a. Summary will update automatically on new commits.