Closed numeric scalar self-call frames

Date: 2026-07-21 Area: bytecode runtime

GocciaScript specializes direct self-calls only when the existing closed-world numeric proof accepts the entire local arrow function and every external call. For proven functions with one to three parameters, non-tail recursive call sites emit OP_CALL_SELF_NUM. The instruction enters the same function template with a compact scalar frame and a new register window while sharing the generic entry frame's closure, lexical environment, local-cell and argument windows, realm, new.target, and execution context. It still accounts for the ordinary stack limit, deferred error-stack frames, function profiling, coverage, instruction limits, timeouts, and GC-visible live registers. Tail calls continue through the generic proper-tail-call path.

This is a proof-backed ABI, not speculative specialization. There is no guard or deoptimization path: escapes, mixed or wrong-arity calls, optional/spread calls, defaults, rest/destructuring, unsupported expression forms, and functions with more than three parameters retain OP_CALL. Generic function entry is unchanged. The compiler-only proof name is not serialized; the opcode is, so the bytecode format advances from version 74 to 75.

On the retained untyped Fibonacci probe (25 inner iterations, nine interleaved production samples), the scalar-frame build reduced median wall time from 241,359 us on origin/main to 72,211 us (70.1%), and from 228,870 us on the numeric-superinstruction predecessor to 72,722 us (68.2%). Deterministic one-iteration dispatch fell from 262,915 opcodes on origin/main to 164,408; generic OP_CALL plus self OP_GET_UPVALUE dispatches fell from 43,785 to five ordinary outer calls. The pinned AWFY Sieve guard remained within matched noise: 95,453 us versus 95,032 us on the predecessor (0.44% slower), and 95,254 us versus 97,003 us on origin/main (1.8% faster). This narrowly satisfies the end-to-end evidence requirement behind ADR 0089 without introducing a general fixed-arity calling convention.