if p.Kind != BlockIf {
					continue
				}
				if p.Controls[0] != a {
					continue
				}
				if e.i == 0 {
					if ct == nil {
						ct = f.ConstBool(f.Config.Types.Bool, true)
					}
					v.SetArg(i, ct)
				} else {
					if cf == nil {
						cf = f.ConstBool(f.Config.Types.Bool, false)
					}
					v.SetArg(i, cf)
				}
			}
		}
	}

	// Step 2: Redirect control flow around known branches.
	// p:

	f := c.Fun("entry",
		Bloc("entry",
			Valu("mem", OpInitMem, types.TypeMem, 0, nil),
			Exit("mem")))
	v1 := f.f.ConstBool(c.config.Types.Bool, false)
	v2 := f.f.ConstBool(c.config.Types.Bool, true)
	f.f.freeValue(v1)
	f.f.freeValue(v2)
	v3 := f.f.ConstBool(c.config.Types.Bool, false)
	v4 := f.f.ConstBool(c.config.Types.Bool, true)
	if v3.AuxInt != 0 {
		t.Errorf("expected %s to have auxint of 0\n", v3.LongString())
	}

const (
	constSliceMagic       = 1122334455
	constInterfaceMagic   = 2233445566
	constNilMagic         = 3344556677
	constEmptyStringMagic = 4455667788
)

// ConstBool returns an int constant representing its argument.
func (f *Func) ConstBool(t *types.Type, c bool) *Value {
	i := int64(0)
	if c {
		i = 1
	}
	return f.constVal(OpConstBool, t, i, true)
}
func (f *Func) ConstInt8(t *types.Type, c int8) *Value {

	(LoweredZero [s] destptr mem)

// Lowering constants
(Const64 ...) => (I64Const ...)
(Const(32|16|8) [c]) => (I64Const [int64(c)])
(Const(64|32)F ...) => (F(64|32)Const ...)
(ConstNil) => (I64Const [0])
(ConstBool [c]) => (I64Const [b2i(c)])

// Lowering calls
(StaticCall ...) => (LoweredStaticCall ...)
(ClosureCall ...) => (LoweredClosureCall ...)
(InterCall ...) => (LoweredInterCall ...)

(NeqB ...) => (XOR ...)
(Not x) => (XORconst [1] x)

// constants
(Const(64|32|16|8) [val]) => (MOVVconst [int64(val)])
(Const(32|64)F [val]) => (MOV(F|D)const [float64(val)])
(ConstNil) => (MOVVconst [0])
(ConstBool [t]) => (MOVVconst [int64(b2i(t))])

(Slicemask <t> x) => (SRAVconst (NEGV <t> x) [63])

// truncations
// Because we ignore high parts of registers, truncates are just copies.
(Trunc16to8 ...) => (Copy ...)

(Const(64|32|16|8) [val]) => (MOVDconst [int64(val)])
(Const32F [val]) => (FMVSX (MOVDconst [int64(math.Float32bits(val))]))
(Const64F [val]) => (FMVDX (MOVDconst [int64(math.Float64bits(val))]))
(ConstNil) => (MOVDconst [0])
(ConstBool [val]) => (MOVDconst [int64(b2i(val))])

(Addr {sym} base) => (MOVaddr {sym} [0] base)
(LocalAddr <t> {sym} base mem) && t.Elem().HasPointers() => (MOVaddr {sym} (SPanchored base mem))

(NeqB ...) => (XOR ...)
(Not x) => (XORconst [1] x)

// constants
(Const(32|16|8) [val]) => (MOVWconst [int32(val)])
(Const(32|64)F ...) => (MOV(F|D)const ...)
(ConstNil) => (MOVWconst [0])
(ConstBool [t]) => (MOVWconst [b2i32(t)])

// truncations
// Because we ignore high parts of registers, truncates are just copies.
(Trunc16to8 ...)  => (Copy ...)
(Trunc32to8 ...)  => (Copy ...)

(NeqB ...) => (XOR ...)
(Not x) => (XORconst [1] x)

// constants
(Const(64|32|16|8) [val]) => (MOVVconst [int64(val)])
(Const(32|64)F [val]) => (MOV(F|D)const [float64(val)])
(ConstNil) => (MOVVconst [0])
(ConstBool [t]) => (MOVVconst [int64(b2i(t))])

(Slicemask <t> x) => (SRAVconst (NEGV <t> x) [63])

// truncations
// Because we ignore high parts of registers, truncates are just copies.
(Trunc16to8 ...) => (Copy ...)

	// arg0=ptr/int arg1=mem, output=int/ptr
	{name: "Convert", argLength: 2, zeroWidth: true, resultInArg0: true},

	// constants. Constant values are stored in the aux or
	// auxint fields.
	{name: "ConstBool", aux: "Bool"},     // auxint is 0 for false and 1 for true
	{name: "ConstString", aux: "String"}, // value is aux.(string)
	{name: "ConstNil", typ: "BytePtr"},   // nil pointer