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https://github.com/RetroPortingToolKit/psxrecomp
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Matthew Stanley
94a1966444
The complete §25 fix: make BOTH recompiler emitters emit guest calls as TAIL-TRANSFERS driven by the unified flat trampoline + the guest's own $ra/$sp, instead of nesting one host C frame per guest call. The host stack can no longer mirror unbounded guest re-entrancy — the architectural root of the ~14-min idle freeze. Gated gen-time by PSX_CPS; legacy codegen byte-identical when unset. VALIDATED (user): full-CPS Tomba boots BIOS -> FMV -> New Game -> village idle and plays; ce_profile cur_max_kb FLAT at 5 KB from frame ~9.9k through 56,890 (turbo soak) — blew past the ~50k-frame freeze threshold with the host stack bounded (legacy climbed +1.17 KB/frame -> 48 MB -> freeze). KEY CORRECTION to the prior session's §25.1: there are TWO emitters. The BIOS (full_function_emitter.cpp) was done last session but the §8 leaking chain (func_8001A954 ...) is GAME code, emitted by code_generator.cpp (via main_psx.cpp) — never converted. Also, §25.1's "continuations not in the dispatch table" hypothesis was wrong (they were always added); the real boot regressions were found by dumping the always-on fntrace ring on the abnormal psx_dispatch return. Emitter changes (gated PSX_CPS): - full_function_emitter.cpp (BIOS): BIOS A0/B0/C0 vector runtime-fallback tail-transfers instead of nested psx_dispatch_call (was the frame-0 exit). - code_generator.cpp/.h (game): jal/jalr/jr-$ra/jr-table/branch-split/j-split -> tail-transfer (jalr captures rs before the link, alias-safe); each call's return point registered as a dispatchable continuation; entry-switch (keyed on cpu->pc) at the top of every function AND every overlapping-alias body. 0 psx_call_contract / call_by_address emitted under CPS. - main_psx.cpp: psx_dispatch_game_compiled gains continuation cases (case cont: cpu->pc=cont; func_owner(cpu)); entries clear cpu->pc. - strict_translator.cpp: syscall emits `if (psx_syscall(...)) return;` so a void syscall falls through to the inline post-syscall jr $ra (real-HW EPC+4). Runtime changes (the legacy "return via nested dispatch / cpu->pc=0" idioms that exit the flat CPS trampoline): - traps.c: psx_syscall returns int (0=void/fall-through, 1=transfer); Enter/ExitCriticalSection return 0; case-3 ChangeThread-success returns 0 — the fiber scheduler leaves cpu->pc=0 on resume, which was the frame-712 exit. - cpu_state.h / overlay_api.h: psx_syscall signature void->int; overlay callback ABI bumped 4->5 (stale overlay caches rejected). - dirty_ram_interp.c: gate interp_enter_compiled behind PSX_HAS_GAME_DISPATCH (un-breaks the BIOS-only build). - main.cpp: dump the always-on fntrace ring tail + stack to psx_cps_exit_trace.json on an abnormal psx_dispatch return (diagnostic; CLAUDE.md ring-buffer model). Docs: RECURSION_BUG.md §25.2-§25.4. Remaining: dwarf->overworld playtest; Stage 3 (sljit/overlay CPS parity); then consider making CPS default. Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>