var numbers = []int64{
		1, 0, -1,
		2, -2,
		1<<63 - 1, -1 << 63,
	}
	coverage := map[flagConstant]bool{}
	for _, x := range numbers {
		for _, y := range numbers {
			a := logicFlags64(x & y)
			b := flagRegister2flagConstant(asmAndFlags(x, y), false)
			if a != b {
				t.Errorf("asmAnd diff: x=%x y=%x got=%s want=%s\n", x, y, a, b)
			}
			coverage[a] = true
		}
	}
	if len(coverage) != 3 {

	fcb.V = x >= 0 && y < 0 && x-y < 0 || x < 0 && y >= 0 && x-y >= 0
	return fcb.encode()
}

// logicFlags64 returns flags set to the sign/zeroness of x.
// C and V are set to false.
func logicFlags64(x int64) flagConstant {
	var fcb flagConstantBuilder
	fcb.Z = x == 0
	fcb.N = x < 0
	return fcb.encode()
}

// constant comparisons
(CMPconst  (MOVDconst [x]) [y]) => (FlagConstant [subFlags64(x,y)])
(CMPWconst (MOVDconst [x]) [y]) => (FlagConstant [subFlags32(int32(x),y)])
(TSTconst  (MOVDconst [x]) [y]) => (FlagConstant [logicFlags64(x&y)])
(TSTWconst (MOVDconst [x]) [y]) => (FlagConstant [logicFlags32(int32(x)&y)])
(CMNconst  (MOVDconst [x]) [y]) => (FlagConstant [addFlags64(x,y)])

	v_0 := v.Args[0]
	// match: (TSTconst (MOVDconst [x]) [y])
	// result: (FlagConstant [logicFlags64(x&y)])
	for {
		y := auxIntToInt64(v.AuxInt)
		if v_0.Op != OpARM64MOVDconst {
			break
		}
		x := auxIntToInt64(v_0.AuxInt)
		v.reset(OpARM64FlagConstant)
		v.AuxInt = flagConstantToAuxInt(logicFlags64(x & y))
		return true
	}
	return false
}