Segment-aware code, rollout PR B (docs/SEGMENT_AWARE_CODE.md §5.2).
Game/overlay emitter: CodeGenerator gains a code segment and
runtime_pc(addr) = code_seg | phys. Links (including a jalr in a branch
delay slot), fetch tags and the uncached-fetch test in emit_pre_icache,
interrupt resume PCs, CPS exit PCs and continuation keys, store-PC
stamps, the reserved-instruction EPC, the slice resume PC,
call_by_address and stale-guard targets, the call contract's return PC,
cosim PCs, the VSync-query hook's base PC, the data stubs'
unknown-dispatch PC and the dispatch rows' addr/resume_pc all go through
it. func_/block_ names, .ranges and entry-hook ids keep the compile
address. The VSync-query hook is not emitted for an uncached code
segment: its hand-timed body charges cached fetches only. The segment
defaults to the image's own, so runtime_pc(addr) == addr for every
existing input and KSEG0 titles regenerate byte for byte.
BIOS emitter: StrictTranslator::translate(d, runtime_pc) stamps stores,
the syscall EPC and the break and unaligned-access PCs with the PC the
code runs at; the psx_ldd_ temporaries keep the ROM address. The
full-function emitter passes relocate_ra() to every translate() call and
publishes the runtime PC on a fallthrough. Relocated kernel and shell
code therefore stamps its RAM address, as the interpreter does.
memory.c re-keys, in the same change, the seven SCPH-1001 store-PC keys
that named ROM addresses of relocated code: RAM-0 filters 0x00000F00
(ROM 0xBFC10A00), 0x80056EB4, 0x800585E4, 0x80058788, 0x80059C50 (ROM
0xBFC3EEB4/405E4/40788/41C50), the opt-in Tomba EvCB key 0x00001CE4 (ROM
0xBFC117E4) and the GP0 source key 0x80050B1C (ROM 0xBFC38B1C). Without
the re-key the new stamps would silently disable all seven. A RAM PC is
ambiguous where the ROM key was not, so each key goes through
scph1001_relocated_store(pc, rom): it matches only while the active
image is SCPH-1001 and the word at pc is still the ROM word copied
there. Other BIOSes and game code at those addresses never match, as
before.
Tests: emitter_runtime_pc_test (new, CTest, run with PSX_CPS unset and
set to 0) compiles a small program through generate_all_functions with
the code segment left default, KSEG0, KUSEG and KSEG1, in CPS,
CPS-overlay and legacy mode. It requires every emission path to be
reached and checks every guest-visible PC class, the identity keys,
physical-only differences and KSEG1 per-instruction fetch charging, and
the translator's runtime PCs in every PC-bearing form. The ledger gains
two regression guards: bios-runtime-pc (OpenBIOS output, plus every
translate() call site) and store-pc-keys-runtime (memory.c keys against
SCPH1001.toml's windows). KNOWN_GAPS is unchanged: B closes no ledger id
on its own (§5.2).
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
The owner settled §10's four questions on 2026-09-29, all as recommended:
- I-cache tags follow Beetle; the hardware bit-31 difference is recorded
in ACCURACY_BURNDOWN axis 4.
- Segment misses in static game code interpret loudly until the title is
regenerated.
- Extra segments are requested through segment-qualified seeds.
- The overlay cache uses per-segment subdirectories.
The doc called g_debug_last_store_pc a debug/identity hook. It is not:
memory.c's RAM 0x0-0xF store filters compare it with exact PCs in every
build, the interpreter stamps the full PC, and #420 (ABI v24) forwards
overlay stamps to the host. §3.1 now lists it as a baked PC, and §5.2
routes it through runtime_pc(). Consequences:
- Option A, re-measured with the 1,261 store-PC stamps in the three R4
shards: +3.8 % / +27.6 % __TEXT (was +3.2 % / +27.2 %).
- New ledger id store-pc-segment (10 KSEG0 stamps in the synthetic EXE's
home bodies), closed by §5.3. The ledger now has 10 known gaps.
- §9: several filter keys are ROM addresses of BIOS code that runs
relocated in SCPH1001. The BIOS emitter stamps ROM addresses and the
interpreter stamps runtime PCs, so the keys must be re-keyed when the
BIOS stamp moves to runtime_pc().
§8 notes that rollout PR A (fix/uncached-fetch-per-insn, based on master)
is being prepared. A has since landed as #429, so the ledger does not
list bios-kseg1-fetch-charge.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Compiled code bakes KSEG0 into link values, CPS/IRQ resume PCs and I-cache
tags. KUSEG-linked EXEs run KUSEG PCs through those bodies (and their KUSEG
seeds are dropped), and overlay code executed at KUSEG/KSEG1 stays
interpreted after #417. Until #429, both emitters also charged the uncached
KSEG1 fetch only at cache-line leaders, so compiled BIOS ROM code was 4
cycles short on 5,477 of OpenBIOS's 9,592 KSEG1 instruction sites (Beetle
and the interp charge every fetch).
docs/SEGMENT_AWARE_CODE.md recommends per-segment compiled variants (code
identity = full VA, emitter segment as a per-compile constant, exact-segment
dispatch, per-instruction fetch in uncached bodies, segment-aware capture
and cache keys) over segment-relative emission, which measures +3.2 % /
+27.2 % __TEXT on R4 shards.
tools/segment_testrom/gen_segment_exe.py emits a synthetic KUSEG-linked
PS-X EXE that also works as an oracle probe. The new ctest
segment_aware_codegen runs the real recompilers on it and on OpenBIOS and
checks emitted PCs, the emitted dispatch lookup and fetch cycles (through
runtime/src/psx_icache.c) against a Beetle ReadInstruction transcription.
It passes only while the observed gaps equal its ledger (9 today).
#429 (rollout A) fixed the BIOS undercharge on master before this landed,
so KNOWN_GAPS does not list bios-kseg1-fetch-charge: the OpenBIOS check
finds no uncharged KSEG1 site and stays as a regression guard that reports
the id as a new gap. The last commit of this series brings the doc up to
date with #429.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Shokunin