//go:noescape
func chacha20Poly1305Seal(dst []byte, key []uint32, src, ad []byte)

var (
	useAVX2 = cpu.X86.HasAVX2 && cpu.X86.HasBMI2
)

// setupState writes a ChaCha20 input matrix to state. See
// https://tools.ietf.org/html/rfc7539#section-2.3.
func setupState(state *[16]uint32, key *[32]byte, nonce []byte) {
	state[0] = 0x61707865
	state[1] = 0x3320646e
	state[2] = 0x79622d32
	state[3] = 0x6b206574

	}

	return s
}

// setUpdate is provided by package runtime.
// It calls update(def, env), where def is the default GODEBUG setting
// and env is the current value of the $GODEBUG environment variable.
// After that first call, the runtime calls update(def, env)
// again each time the environment variable changes
// (due to use of os.Setenv, for example).
//
//go:linkname setUpdate
func setUpdate(update func(string, string))

var godebugEnv atomic.Pointer[string] // set by parsedebugvars
var godebugNewIncNonDefault atomic.Pointer[func(string) func()]

//go:linkname godebug_setUpdate internal/godebug.setUpdate
func godebug_setUpdate(update func(string, string)) {
	p := new(func(string, string))
	*p = update
	godebugUpdate.Store(p)
	godebugNotify(false)
}