Documentation only. Prior sessions kept re-deriving state from breadcrumbs that
were no longer true:
- overlay_sljit.c / code_provider.{h,c}: corrected "declines every fragment" and
"compile_fragment not yet called from dispatch" — the MIPS->sljit emitter is
fully implemented and wired (then validated via the same-state diff).
- ISSUES.md: add Issue #7 (sljit live execution was unvalidated; the pure-live
save-load wedge), root cause and fix recorded.
(SLJIT.md — the §11 forward plan and architecture clarification — lives at the
workspace root F:/Projects/psxrecomp/SLJIT.md, outside this repo, updated
separately.)
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
The MIPS->sljit emitter, paralleling dirty_ram_interp.c's exec_one but
emitting host code. First slice = single-block LEAF functions ending in
`jr $ra`; everything else aborts the whole fragment to the interpreter
(precision over recall).
- overlay_sljit.c: memory-backed GPRs, 32-bit ops (R3000A wraparound),
loads/stores via icall through the cpu read/write callbacks (same
MMIO/page-watch/dirty-tracking path as the interpreter). Opcodes:
SLL/SRL/SRA/SLLV/SRLV/SRAV, ADD(U)/SUB(U), AND/OR/XOR/NOR, SLT(U),
ADDI(U)/SLTI(U)/ANDI/ORI/XORI/LUI, LB/LH/LW/LBU/LHU/SB/SH/SW, SYNC.
- compile_fragment now returns CompiledFragment{fn,code_lo,code_len};
overlay_loader registers an sljit candidate (crc hashed from the live
bytes it JIT'd from, same live-byte validation as gcc candidates).
- Step 5 wiring is VALIDATION-GATED: JIT-on-miss fires only when
backend==sljit AND the same-state differential is armed (never in a
shadow run). Normal play stays byte-identical; live sljit execution
stays off until the differential gate passes.
- Debug: sljit_try <addr> probe; sljit_status reports shards_registered.
Verified: runtime/tests/sljit_emit_test.c (links overlay_sljit.c +
sljitLir.c only) JITs hand-built leaf functions and checks output —
26/26 pass incl. gpr0 invariant, sign/zero-ext, signed/unsigned compare,
and the decline cases. Full psx-runtime build clean.
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
Introduce one backend-agnostic code-production seam the overlay
capture/dispatch spine talks to, and make the validated gcc spawn->DLL
path its first implementation. Pure refactor; gcc stays the default and
its behavior is byte-identical.
- New code_provider.h/.c: a CodeProvider struct exposing BOTH production
lifecycles so the interface isn't gcc-shaped -- batch/async
(request/busy/poll_main, the gcc model) and sync-on-miss
(compile_fragment, the sljit model). compile_fragment is defined and
implemented per-provider but not yet called from dispatch (step 5).
gcc provider = direct pass-throughs to autocompile_* (compile_fragment
NULL: a compiler spawn is too slow for the dispatch path); sljit
provider wraps overlay_sljit_* (still declines every fragment).
- Wire up overlay_backend_resolve, which was previously dead code:
code_provider_init() resolves the backend at overlay-cache init and
caches the active provider; code_provider_active() is the accessor.
- Add [runtime] overlay_backend config (auto|gcc|sljit; empty=auto) so
resolution has a config source alongside PSX_OVERLAY_BACKEND.
- Route the 3 direct autocompile_* call sites through the active
provider: overlay_capture.c autocapture tick, main.cpp per-frame poll
+ the init call, debug_server.c autocompile_run (now reports backend).
- runtime.cmake += code_provider.c.
Builds + links clean (TombaRecomp/build-dev, MinGW gcc 15.2).
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
Matthew Stanley