Constant LOGOS_MEMMEM_DEOPT 

pub const LOGOS_MEMMEM_DEOPT: i64 = i64::MIN; // -9_223_372_036_854_775_808i64

The deopt sentinel logos_rt_memmem returns when the recognized search nest would, on bytecode, take an access the helper cannot reproduce in-bounds — a checked needle index past the needle buffer (needleLen > len(needle)). The caller’s stencil routes this to a side exit so the VM replays from the region head on bytecode and raises the EXACT same error at the EXACT same point. i64::MIN is never a legitimate count (a count is in [0, haystack_len]).