does not exist, <code>delete</code> is a no-op.
</p>


<h3 id="Complex_numbers">Manipulating complex numbers</h3>

<p>
Three functions assemble and disassemble complex numbers.
The built-in function <code>complex</code> constructs a complex
value from a floating-point real and imaginary part, while
<code>real</code> and <code>imag</code>

// different sets of packages. If a package matches patterns given in
// multiple flags, the latest match on the command line wins.
// For example, 'go build -gcflags=-S fmt' prints the disassembly
// only for package fmt, while 'go build -gcflags=all=-S fmt'
// prints the disassembly for fmt and all its dependencies.
//
// For more about specifying packages, see 'go help packages'.
// For more about where packages and binaries are installed,

		return strings.HasPrefix(s.Name, "libc_")
	}
	return ctxt.Arch.Family == sys.I386 && !ctxt.Flag_shared
}

// single-instruction no-ops of various lengths.
// constructed by hand and disassembled with gdb to verify.
// see http://www.agner.org/optimize/optimizing_assembly.pdf for discussion.
var nop = [][16]uint8{
	{0x90},
	{0x66, 0x90},
	{0x0F, 0x1F, 0x00},
	{0x0F, 0x1F, 0x40, 0x00},

	case 45: /* sxt/uxt[bhw] R,R; movT R,R -> sxtT R,R */
		as := p.As
		rt, rf := p.To.Reg, p.From.Reg
		if rf == REGZERO {
			as = AMOVWU /* clearer in disassembly */
		}
		switch as {
		case AMOVB, ASXTB:
			o1 = c.opbfm(p, ASBFM, 0, 7, rf, rt)

		case AMOVH, ASXTH:
			o1 = c.opbfm(p, ASBFM, 0, 15, rf, rt)

		case AMOVW, ASXTW: