case scanner.Ident:
			// Is it a macro name?
			name := in.Stack.Text()
			macro := in.macros[name]
			if macro != nil {
				nesting++
				in.invokeMacro(macro)
				continue
			}
			fallthrough
		default:
			if tok == scanner.EOF && len(in.ifdefStack) > 0 {
				// We're skipping text but have run out of input with no #endif.
				in.Error("unclosed #ifdef or #ifndef")
			}

				p.errorf("invalid vtype: %v", err)
			}
			prog.AddRestSourceArgs([]obj.Addr{a[1], a[2], a[3], a[4]})
			prog.To = a[5]
			break
		}
		fallthrough
	default:
		p.errorf("can't handle %s instruction with %d operands", op, len(a))
		return
	}

	p.append(prog, cond, true)
}

</p>

<h3 id="Fallthrough_statements">Fallthrough statements</h3>

<p>
A "fallthrough" statement transfers control to the first statement of the
next case clause in an <a href="#Expression_switches">expression "switch" statement</a>.
It may be used only as the final non-empty statement in such a clause.
</p>

<pre class="ebnf">
FallthroughStmt = "fallthrough" .
</pre>

	r := rand.New(rand.NewSource(99))
	for i := range x {
		switch r.Intn(10) {
		case 0:
			x[i] = ' '
		case 1:
			if i > 0 && x[i-1] == 'x' {
				copy(x[i-1:], "χ")
				break
			}
			fallthrough
		default:
			x[i] = 'x'
		}
	}
	return x
}

var makeFieldsInputASCII = func() []byte {
	x := make([]byte, 1<<20)
	// Input is ~10% space, rest ASCII non-space.

xk[44:51] and cipher LXVD2X (R9+R5), V1 LXVD2X (R10+R5), V2 BEQ CR2, Ldec_tail // Key size 12? VCIPHER V0, V1, V0 VCIPHER V0, V2, V0 // Load xk[52:59] and cipher LXVD2X (R11+R5), V1 LXVD2X (R12+R5), V2 BNE CR3, Linvalid_key_len // Not key size 14? // Fallthrough to final cipher Ldec_tail: // Cipher last two keys such that key information is // cleared from V1 and V2. VCIPHER V0, V1, V1 VCIPHERLAST V1, V2, V2 // Store the result in BE order. P8_STXVB16X(V2, R3, R0) RET Linvalid_key_len: // Segfault, this...