Runtime Dispatch

A Device is the host CPU, from CPU(), or a GPU by its runtime’s own ordinal, from NewDevice(DeviceCUDA, 0) and its DeviceROCm and DeviceMetal twins, counted by CountDevices. Device.ConfigureThread pins the current goroutine to an OS thread via runtime.LockOSThread, enables the CPU-specific state the given capabilities need, such as Intel AMX tiles, then returns an unlock function. Goroutines can migrate between OS threads, so thread-local state (AMX tiles) would be lost without pinning.

cpu := nk.CPU()
enabled, _ := cpu.CapabilitiesEnabled() // what dispatch runs within: detected on this CPU and compiled in
unlock, _ := cpu.ConfigureThread(enabled) // lock thread, configure what dispatch uses
defer unlock()                            // release the OS thread on return

fmt.Println(enabled)                 // like "serial,neon,neonhalf,neonfhm,neonsdot"
fmt.Println(enabled.Has(nk.CapNEON)) // test one capability

if gpu, err := nk.NewDevice(nk.DeviceMetal, 0); err == nil {
	fmt.Println(gpu.CapabilitiesEnabled()) // like "metal,apple9"
}

CapabilitiesDetected and CapabilitiesCompiled report the two raw axes, what the device executes and what this binary contains for its kind. Every kernel call passes CapCPUs, which the library clamps to the CPU’s CapabilitiesEnabled, settled as it loads, so the package keeps no mask of its own. Every capability is a typed Capability constant, like CapSerial, CapNEON, CapHaswell, CapSapphireAMX, CapSME, CapAmpere, and CapApple9, and CapCPUs, CapGPUs, and CapAny group them. These are useful for logging the active platform or gating optional benchmark paths.