Root cause investigation of WASM kernel timeout for tests 200, 207, 211:
verified the kernel's __hs_deadline check IS firing correctly with the
JS-side _testDeadline value. The tests were genuinely taking 60s+ because
the (raise msg) inside hs-null-error! propagated up through the JIT
continuation chain and triggered the slow host_error path (~34s per
comment in the test runner override).
The companion helpers hs-null-raise! and hs-empty-raise! already wrap
their raise in (guard (_e (true nil)) (raise msg)) so the exception
is swallowed before escaping. hs-null-error! was missing this guard —
it just did (raise (str ...)).
Fix: hs-null-error! now sets window._hs_null_error and uses the same
self-contained guard pattern. The error message is still recoverable
through the side channel, matching how the eval-hs-error override in
the test harness expects to find it.
Bumped hypertrace deadlines 8s→30s (modules-loaded JIT state has grown
since the original 8s budget was set).
Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
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>
Added short aliases make-buffer / buffer? / buffer-append! / buffer->string /
buffer-length on both OCaml and JS hosts, sharing the existing StringBuffer
value type. buffer-append! auto-coerces non-strings via inspect.
Rewrote the OCaml host inspect function to walk a single shared Buffer.t
instead of allocating O(n) intermediate strings via String.concat at every
recursion level. inspect underlies sx-serialize and error-path formatting,
so this benefits the tightest serialization paths.
Median improvements (bin/bench_inspect.exe, best-of-3 of 9-run min):
tree-d8 (75KB): 5.31ms -> 1.30ms (-76%)
tree-d10 (679KB): 81.89ms -> 16.02ms (-80%)
dict-1000: 0.80ms -> 0.31ms (-61%)
list-2000: 0.74ms -> 0.33ms (-55%)
Tests: OCaml 4545 -> 4550. JS 2591 -> 2596. Zero regressions.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
CEK frames were already records (cek_frame in sx_types.ml), so the actual
hot-path bottleneck was prim_call "=" [...] in step_continue/step_eval
dispatch: each step did a Hashtbl lookup + 2x list cons + pattern match
just to compare frame-type strings.
Added a short-circuit fast path in prim_call (sx_runtime.ml) for the
hot operators: =, <, >, <=, >=, empty?, first, rest, len. These bypass
the primitives Hashtbl entirely and dispatch directly on value shape.
Inlined _fast_eq for scalar/string equality, which dominates frame-type
dispatch comparisons.
Added bin/bench_cek.exe with five tight-loop benchmarks (fib, loop,
map, reduce, let-heavy). Median of 7 runs:
fib(18) 2789ms -> 941ms (-66%)
loop(5000) 2018ms -> 620ms (-69%)
map sq xs(1000) 108ms -> 48ms (-56%)
reduce + ys(2000) 72ms -> 10ms (-86%)
let-heavy(2000) 491ms -> 271ms (-45%)
Tests: 4545/4545 passing baseline preserved (1339 pre-existing failures
unchanged).
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
