v0.AddArg(x)
		v.AddArg2(v0, x)
		return true
	}
}
func rewriteValuedec64_OpSignExt8to64(v *Value) bool {
	v_0 := v.Args[0]
	b := v.Block
	typ := &b.Func.Config.Types
	// match: (SignExt8to64 x)
	// result: (SignExt32to64 (SignExt8to32 x))
	for {
		x := v_0
		v.reset(OpSignExt32to64)
		v0 := b.NewValue0(v.Pos, OpSignExt8to32, typ.Int32)
		v0.AddArg(x)
		v.AddArg(v0)
		return true

// Lowering extension
// Note: we always extend to 64 bits even though some ops don't need that many result bits.
(SignExt8to16  ...) => (MOVBQSX ...)
(SignExt8to32  ...) => (MOVBQSX ...)
(SignExt8to64  ...) => (MOVBQSX ...)
(SignExt16to32 ...) => (MOVWQSX ...)
(SignExt16to64 ...) => (MOVWQSX ...)
(SignExt32to64 ...) => (MOVLQSX ...)

(ZeroExt8to16  ...) => (MOVBQZX ...)
(ZeroExt8to32  ...) => (MOVBQZX ...)