nx_js_floatfuse_probe.nx

nx_js_floatfuse_probe.nx -- SELF-ASSERTING perf-regression GATE for the const-fusion float fallback. `s=s+1` with `s` a FLOAT is the `float +/- int-literal` pattern: it fuses (PUSH 1 is an int const) but the LHS is float at runtime -> the fast path misses -> fallback. The fallback MUST use jit_binop's inline SSE (addsd), NOT the ~10x-slower jit_slow_binop sovereign slow-helper call. This gate catches that regression AUTOMATICALLY (the correctness suite can't -- it's bit-exact, not timed): the SSE fallback puts the FLOAT loop within ~1.2x of the pure-INT control (both are ~1 mem-round-trip/iter); the broken sovereign-slow-helper made it ~10x. Assert float < 4x int (clean separation, robust to the machine's +-25% load noise). This is the gate that would have caught the 2026-07-14 10x regression. expect_exit: 0 license_tier: ORIGINAL