The bytecode compiler emitted OP_CALL_PRIM (52) for every primitive call, even
for arithmetic and comparison hot-paths. The VM had specialized opcodes
(OP_ADD, OP_SUB, OP_EQ, etc.) defined but unused.
- lib/compiler.sx (compile-call): emit specialized 1-byte opcode when the
primitive name + arity matches one of {+, -, *, /, =, <, >, cons, not, len,
first, rest}. Falls back to CALL_PRIM otherwise. fib bytecode: 50 → 38 bytes.
- hosts/ocaml/lib/sx_compiler.ml: mirror change in the auto-generated OCaml
compiler so SXBC export from mcp_tree uses the same emission.
- hosts/ocaml/lib/sx_vm.ml: extend OP_ADD/SUB/MUL/DIV to handle Integer+Integer
(not just Number+Number). Inline OP_EQ via Sx_runtime._fast_eq. Inline
OP_LT/GT mixed-numeric comparisons. Avoids Hashtbl lookup on the fallback
path for the common integer cases that dominate tight loops.
- hosts/ocaml/bin/bench_vm.ml: VM-only benchmark — loads compiler.sx via CEK,
JIT-compiles each fn, measures Sx_vm.call_closure throughput.
Median improvements (best of 3 runs of 9-min, bench_vm.exe):
fib(22) 107.87ms → 33.13ms -69%
loop(200000) 429.64ms → 161.16ms -62%
sum-to(50000) 72.85ms → 36.74ms -50%
count-lt(20000) 28.44ms → 17.58ms -38%
count-eq(20000) 37.23ms → 15.46ms -58%
Tests: 4550/4550 OCaml passing (unchanged). Zero regressions.
Last step in the sx-improvements roadmap — all 14 steps complete.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
Compiler (lib/compiler.sx):
- Fix emit-op return type: 8 definition form cases (defstyle,
defhandler, defpage, etc.) and the perform case now return nil
explicitly via (do (emit-op em N) nil) instead of bare emit-op
which transpiled to unit-returning OCaml.
- compile_match PREAMBLE: return Nil instead of unit (was ignore).
- Added init wrapper to PREAMBLE (needed by compile-module).
- All 41 compiler functions re-transpiled cleanly.
Render (bootstrap_render.py): re-transpiled, no changes.
Runtime: restored keyword_p predicate (needed by defio-parse-kwargs!
in the transpiled evaluator).
2608/2608 tests passing.
Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
Sx_compiler.compile/compile_module now emit arity (local slot count) in
the bytecode dict. MCP sx_build_bytecode serializes arity into .sxbc.json.
sx-platform.js passes arity through to K.loadModule(). Without this, the
VM allocated only 16 local slots per module frame.
Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
