RISC-V Design · All levels

Branch Handling, Pipeline Flush, and Redirect Timing: Reports and Metrics

Reports and Metrics for Branch Handling, Pipeline Flush, and Redirect Timing.

Reports and metrics

Reports and Metrics for Branch Handling, Pipeline Flush, and Redirect Timing is anchored on Branch mispredict penalty in cycles, wrong-path retire count (target zero), and redirect latency from resolve to fetch restart.. Convert observations into mechanism-backed decisions with explicit ownership.

Before/after trend

diagram

BEFORE / AFTER TREND - Branch Handling, Pipeline Flush, and Redirect Timing

Branch mispredict penalty in cycles, wrong-path retire count (target zero), and redirect latency from resolve to fetch restart.
  ^
  |                           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 - Branch Handling, Pipeline Flush, and Redirect Timing

Branch mispredict penalty in cycles, wrong-path retire count (target zero), and redirect latency from resolve to fetch restart. 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 Branch mispredict penalty in cycles, wrong-path retire count (target zero), and redirect latency from resolve to fetch restart. 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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