SOL_PACKET                    = 0xfffd
	SOL_ROUTE                     = 0xfffe
	SOL_SOCKET                    = 0xffff
	SOMAXCONN                     = 0x80
	SO_ACCEPTCONN                 = 0x2
	SO_ALL                        = 0x3f
	SO_ALLZONES                   = 0x1014
	SO_ANON_MLP                   = 0x100a
	SO_ATTACH_FILTER              = 0x40000001
	SO_BAND                       = 0x4000

        entities.put("lArr", "\u21d0");
        entities.put("uArr", "\u21d1");
        entities.put("rArr", "\u21d2");
        entities.put("dArr", "\u21d3");
        entities.put("hArr", "\u21d4");
        entities.put("forall", "\u2200");
        entities.put("part", "\u2202");
        entities.put("exist", "\u2203");
        entities.put("empty", "\u2205");
        entities.put("nabla", "\u2207");
        entities.put("isin", "\u2208");

func endsInFallthrough(stmts []ir.Node) (bool, src.XPos) {
	if len(stmts) == 0 {
		return false, src.NoXPos
	}
	i := len(stmts) - 1
	return stmts[i].Op() == ir.OFALL, stmts[i].Pos()
}

// walkSwitchType generates an AST that implements sw, where sw is a
// type switch.
func walkSwitchType(sw *ir.SwitchStmt) {
	var s typeSwitch
	s.srcName = sw.Tag.(*ir.TypeSwitchGuard).X

		slice.Prealloc = n.Prealloc
		args = []ir.Node{buf, slice}
		slice.SetEsc(ir.EscNone)
	}

	cat := typecheck.LookupRuntime(fn)
	r := ir.NewCallExpr(base.Pos, ir.OCALL, cat, nil)
	r.Args = args
	r1 := typecheck.Expr(r)
	r1 = walkExpr(r1, init)
	r1.SetType(n.Type())

	return r1
}

type hookInfo struct {
	paramType   types.Kind
	argsNum     int

			default:
				on = typecheck.LookupRuntime("printstring")
			}
		default:
			badtype(ir.OPRINT, n.Type(), nil)
			continue
		}

		r := ir.NewCallExpr(base.Pos, ir.OCALL, on, nil)
		if params := on.Type().Params(); len(params) > 0 {
			t := params[0].Type
			n = typecheck.Conv(n, t)
			r.Args.Append(n)
		}
		calls = append(calls, r)
	}

	"darr":     "\u2193",
	"harr":     "\u2194",
	"crarr":    "\u21B5",
	"lArr":     "\u21D0",
	"uArr":     "\u21D1",
	"rArr":     "\u21D2",
	"dArr":     "\u21D3",
	"hArr":     "\u21D4",
	"forall":   "\u2200",
	"part":     "\u2202",
	"exist":    "\u2203",
	"empty":    "\u2205",
	"nabla":    "\u2207",
	"isin":     "\u2208",
	"notin":    "\u2209",
	"ni":       "\u220B",
	"prod":     "\u220F",

	case ir.OBLOCK:
		n := n.(*ir.BlockStmt)
		o.stmtList(n.List)

	// Special: n->left is not an expression; save as is.
	case ir.OBREAK,
		ir.OCONTINUE,
		ir.ODCL,
		ir.OFALL,
		ir.OGOTO,
		ir.OLABEL,
		ir.OTAILCALL:
		o.out = append(o.out, n)

	// Special: handle call arguments.
	case ir.OCALLFUNC, ir.OCALLINTER:
		n := n.(*ir.CallExpr)
		t := o.markTemp()
		o.call(n)

	if s.curBlock == nil && n.Op() != ir.OLABEL {
		return
	}

	s.stmtList(n.Init())
	switch n.Op() {

	case ir.OBLOCK:
		n := n.(*ir.BlockStmt)
		s.stmtList(n.List)

	case ir.OFALL: // no-op

	// Expression statements
	case ir.OCALLFUNC:
		n := n.(*ir.CallExpr)
		if ir.IsIntrinsicCall(n) {
			s.intrinsicCall(n)
			return
		}
		fallthrough