Matthew Stanley fade5603fb ruler#2: add give-back probes (load_use, gte_read_use, ld_div) + Δ-gates ...

Adds three cycle-isolation loops that exercise the load-delay give-back
TERMINATION and the two not-yet-modeled give-back interactions, each
measured against the Beetle oracle AT STEADY STATE (Beetle's warm-up
window reports the no-give-back value — the source of the handoff's
mis-recorded "gte_rtps +15 EXACT"; true steady Beetle = +11):

- load_use (lw; addu deps the loaded reg): native +5 == Beetle +5 —
  Δ-validates the GPR_DEP give-back termination shipped in the prior
  commit (load/load2 load into dead regs and never exercise it).
- gte_read_use / gte_rtps / gte_nclip: native OVER-counts by 4-5 — the
  MFC2/CFC2 LDAbsorb give-back (gte_ts_done-now) is unmodeled.
- ld_div (lw; divu; mflo): native UNDER-counts by 4 — the muldiv stall
  must CONSUME the pending lw give-back (Beetle decrements ReadAbsorb
  while stalling MFLO to muldiv_ts_done).

The 8 CPU-load/alu/div/mult components all MATCH at steady state, so the
prior load-interlock commit is solid. The 4 confirmed divergences are
the Δ-gates for the GTE-read/MFC0/muldiv give-back follow-up; spec +
targets in accuracy/load_readfudge_ldabsorb.md.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

2026-06-27 14:29:31 -07:00

..

axis4_memory_mmio.md

docs(accuracy): consolidate 5-axis research findings into burndown

2026-06-26 20:01:59 -07:00

axis5_gpu.md

docs(accuracy): consolidate 5-axis research findings into burndown

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axis5_mdec.md

feat(timing): route BIOS emitter through single-source psx_instr_base_cycles

2026-06-26 19:56:20 -07:00

axis5_sio_controller.md

feat(timing): route BIOS emitter through single-source psx_instr_base_cycles

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axis5_spu.md

feat(timing): route BIOS emitter through single-source psx_instr_base_cycles

2026-06-26 19:56:20 -07:00

load_readfudge_ldabsorb.md

ruler#2: add give-back probes (load_use, gte_read_use, ld_div) + Δ-gates

2026-06-27 14:29:31 -07:00