pub const OBJECTIVE_WIRE: &str = "__objective";Expand description
The phase-kernel wire an inline objective expression is lowered to
(SRD-86). optimize.objective is either a bare wire reference (read
directly off the phase kernel) or an inline expression;
synthesize_phase_scope_bindings lowers the latter to
volatile __objective := <expr> so the optimizer reads exactly one wire
regardless of which form the author wrote. The __ prefix keeps it from
colliding with author-declared outputs (same convention as
synthesize_metric_binding_name).