RISC-V Design · All levels

Vector Lanes and Chaining: Reports and Metrics

Reports and Metrics for Vector Lanes and Chaining.

Reports and metrics

Reports and Metrics for Vector Lanes and Chaining is anchored on Cycles-per-element for dependent vector pipelines under lane-count, memory-bandwidth, and chaining-depth constraints.. Convert observations into mechanism-backed decisions with explicit ownership.

Before/after trend

diagram

BEFORE / AFTER TREND - Vector Lanes and Chaining

Cycles-per-element for dependent vector pipelines under lane-count, memory-bandwidth, and chaining-depth constraints.
  ^
  |                           o target band
  |                    o after fix + reruns
  |             o
  |      o baseline (failing)
  +--------------------------------------------------> iteration
       capture issue      isolate mechanism      close + monitor

Use this view to confirm the gain is causal and stable across seeds.

Root-cause tree

diagram

ROOT CAUSE TREE - Vector Lanes and Chaining

Cycles-per-element for dependent vector pipelines under lane-count, memory-bandwidth, and chaining-depth constraints. regressed
          |
   reproducible on fixed seed?
      /                 \
    no                   yes
    |                     |
env/tool drift       first failing domain?
                     /        |         \
                  decode    execute    memory/MMU
                    |         |            |
               control map  bypass/FU   TLB/walk/perm
                    |
         privilege/CSR side effects checked?

Stop at first confirmed mechanism, then assign explicit owner + fix proof.

Track Cycles-per-element for dependent vector pipelines under lane-count, memory-bandwidth, and chaining-depth constraints. on representative workloads, not just microbenchmarks.
Include build/runtime/privilege metadata in report headers.
Pair performance movement with correctness and reliability checks.
Report tail stability, not only mean uplift.

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