Developer decision (2026-09-24), extending Phase 8's coprocessor/kernel allowance.
Trigger conditions recorded: plain C attempted and mechanism identified; the
inexpressibility is structural rather than a scheduling/allocation tie-break;
integer logic stays in C and scheduling still comes from cc1/maspsx; per-file
header documents the sequence, the reason and the limit.
First accepted instance: the PSX scratchpad stack switch (lui at,0x1f80 /
sw sp,1020(at) / lui sp,0x1f80 / ori sp,sp,0x3dc ... / lw sp,1020(sp)), found
independently by workers A (0x800BC658) and B (0x800BC6EC). A stack-pointer READ
was already covered by the register-name binding and needs no exemption; only the
switch does.
Explicitly does NOT reopen trapping-arithmetic, rare-epilogue or primitive-init.
Christopher Williams
b131dc2c7f