mirror of
https://github.com/RetroPortingToolKit/psxrecomp
synced 2026-10-26 02:11:36 -04:00
Shokunin
7342e6bcd1
Beetle's ReadInstruction never fills an I-cache line for a fetch at 0xA0000000 or above: every such fetch costs +4 and clears the pending load give-back. The dirty-RAM interpreter charges that by fetching at every PC. Both static emitters emitted psx_icache_fetch only at cache-line leaders, which is exact for cached code only. In OpenBIOS, 5,477 of the 9,592 in-place ROM (KSEG1) instruction sites were uncharged: 21,908 cycles short per pass through that code, each also missing its give-back clear. Both emitters now charge a fetch before every instruction whose runtime PC is uncached. The predicate is psx_fetch_uncached in psx_instr_cost.h, which psx_icache.c now uses too. The A0/B0/C0 call-vector native stubs charge one fetch per executed word, so a KSEG1 call pays like the interpreter. Cached code keeps the leader rule. R4's regenerated game C is byte-identical, and the OpenBIOS diff is insertions only. psx_instr_cost.h joins the codegen hash list, since the emitters fold it into emitted code. Tests: - ctest uncached_fetch_charge runs psxrecomp-bios on OpenBIOS and compares per-instruction fetch charges three ways: the compiled fetches, the interpreter's fetch path (psx_icache_fetch_interp) at every PC, and a Beetle transcription. - uncached_fetch_codegen_test checks the game emitter at KSEG1 and KSEG0. Both tests fail on master. This closes bios-kseg1-fetch-charge in the segment_aware_codegen ledger (#419). Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Internal dev-logs & design notes
These are the working design documents and burn-down logs the project was built from. They are historical/working notes, not contributor onboarding docs — they capture decisions, phased plans, and deep subsystem investigations in the order they happened, and some sections are superseded by later ones.
If you're new here, start with the top-level README.md,
then docs/ARCHITECTURE.md,
docs/EXECUTION_MODEL.md,
docs/BUILDING.md, and
CONTRIBUTING.md. Come here when you need the why
behind a specific subsystem.
Plans & roadmap
PLAN.md— the original phased build plan (P1–P6).FAITHFUL_TIMING_PLAN.md— the authoritative cycle-accuracy north-star plan and status log.FIRST_MILESTONE.md— the first-boot milestone gate.STUBS_TO_FIX.md— hardware-stub burn-down (pre-game gate).
Cycle accuracy & timing
PRECISE_IRQ_SLICE.md— exact-instruction IRQ delivery.CYCLE_MODEL_BEETLE.md— the Beetle-derived cycle model.ACCURACY_BURNDOWN.md— full accuracy burn-down across all axes (semantics, cycle, IRQ, MMIO, peripherals, determinism).COSIM_ORACLE.md— the first-divergence co-sim oracle.
BIOS / scheduler
HLE_SCHEDULER_CARVEOUT_PLAN.md— the cooperative-thread scheduler HLE carve-out.WEDGE_load4_shell_rootcause.md— a specific boot-shell wedge root-cause writeup.
Renderer / widescreen
GL_RENDERER_HANDOFF.md— OpenGL renderer design.NATIVE_WIDE_PLAN.md— native-wide 16:9 (GTE FOV) plan.BACKDROP_PRELOAD.md— widescreen backdrop preload.
Project conventions & tracking
PRINCIPLES.md— this repo's debugging and enhancement principles (first-divergence, verified-enhancement HLE). Source comments cite it asdocs/internal/PRINCIPLES.md; a "recomp-template PRINCIPLES.md" citation means a different repo's file.ISSUES.md— the historical framework issue log. Live framework work is tracked in Beads (epicbeads-eio.3), not here.DEBUG.md— the debugging playbook behind the TCP debug server; the command reference itself is../TCP_COMMANDS.md.audit_inventory.md— what the codegen/GTE audit pipeline covers and why.
Overlay design & discovery
overlay-recompilation-design.md— the design and rationale for overlay recompilation.overlay-plan.md— the phased overlay implementation plan.overlay-discovery.md— how overlays are discovered on disc and at runtime.overlay-status.md— living what-works / what's-broken status for the overlay capture/compile/cache path.CASE_A_AOT_GAP.md— the Case-A AOT dispatch-miss gap; cited by therationalefields inrecompiler/seeds/*.json.
BIOS / boot hardening
bios-hardening.md— BIOS boot hardening notes.
GTE / CPU investigations
GTE_LM_FIX.md— the GTElmsaturation-flag fix writeup.TOMBA2_EXC_CONSULT_RESPONSE.md— exception -path consultation response for the Tomba 2 bring-up.
Upstream contributor reviews
upstream/ holds per-PR review notes for community contributions, one file per
change, named <contributor>-<pr>-<topic>.md.
upstream/UPSTREAM_2026-08-20.md— the 2026-08-20 upstreaming sweep: which contributed changes are framework-general and which are title configuration.
Overlay cache internals
SLJIT_PERSIST_CACHE.md— removed. It described the persisted shard cache of the sljit Tier-2 backend, which was deleted in5b7e69b4(2026-07-15). For the current model seeruntime/src/overlay_loader.c(per-entry candidate validity),tools/compile_overlays.py(shard formation and the.rangesmanifest), and../COMPILING_OVERLAYS.md.
Removed
CYCLE_TIMING_ARCH.md— removed. Its cycle-timing architecture sketch was superseded and nothing linked to it. For the current model seeFAITHFUL_TIMING_PLAN.md(the authoritative plan),CYCLE_MODEL_BEETLE.md(the Beetle-derived cycle model), andPRECISE_IRQ_SLICE.md(exact-instruction IRQ delivery).