Module hint 

Branch-prediction hints for hot handlers.

Both functions are identity over bool on every supported target. The call site cost is zero: the compiler inlines them into the containing branch with no runtime effect. What they communicate is intent. A handler that expects the fast path to win 99% of the time writes

if hopper::utils::hint::likely(is_cached) {
    return fast_path(ctx);
}
slow_path(ctx)

and the compiler keeps the fast path straight-line, pushing the spill into the cold branch. The unlikely helper expresses the inverse opposite direction.

On host targets (tests, off-chain tooling) future versions may route through core::intrinsics::likely when that intrinsic is stabilized; the API shape stays identical so user code never needs to change. On SBF the Solana runtime does not expose a branch-weight hint today, so the hint compiles out entirely. Leaving the calls in the code path is safe and free.

Functions

cold_path

Marks the path that calls it as rarely taken. Empty, so it costs no instruction; the optimizer lays the other path out as the fall-through.

likely

Hint the branch condition is probably true. Zero runtime cost on SBF; on host targets it maps to LLVM’s llvm.expect.i1 via core::hint::likely when available, and to an identity otherwise.

unlikely

Hint the branch condition is probably false. Mirror of likely.