a, b = b, a
	}
	fmt.Println(a) // 100-digit Fibonacci number

	// Test a for primality.
	// (ProbablyPrimes' argument sets the number of Miller-Rabin
	// rounds to be performed. 20 is a good value.)
	fmt.Println(a.ProbablyPrime(20))

	// Output:
	// 1344719667586153181419716641724567886890850696275767987106294472017884974410332069524504824747437757
	// false
}

	// leaves enough wiggle room to include n lg n time
	// (it actually tests for O(n^log_2(3)).
	// To prevent false positives, average away variation
	// by doing multiple rounds within a single run.
	checkLinear("iterdelete", 2500, func(n int) {
		for round := 0; round < 4; round++ {
			m := map[int]int{}
			for i := 0; i < n; i++ {
				m[i] = i
			}
			for i := 0; i < n; i++ {
				for k := range m {
					delete(m, k)

				// Row is determined by the 1st and 6th bit.
				// Column is the middle four bits.
				row := uint8(((i & 2) << 4) | i&1)
				col := uint8(j << 1)
				t := row | col

				// The rotation was performed in the feistel rounds, being factored out and now mixed into the feistelBox.
				f = (f << 1) | (f >> 31)

				feistelBox[s][t] = uint32(f)
			}
		}
	}
}

// permuteInitialBlock is equivalent to the permutation defined

	// fixed buffer length to optimize. The longer the length, the faster; but
	// only buffers longer than this length will use the optimization. We choose
	// two cutoffs and compute tables for both:
	//  - one around 512: 168*3=504
	//  - one around 4KB: 1344*3=4032
	//
	// -- The nitty gritty --
	//
	// Let CRC(I, X) be the non-inverted CRC32-C of the sequence X (with
	// initial non-inverted CRC I). This function has the following properties:

  int pw;  // Padding on "width" dimension (both sides).

  int sh;  // Stride on "height" dimension.
  int sw;  // Stride on "width" dimension.

  bool ceil_mode;  // Rounding strategy (ceil or floor).
};

// Rounds the dimension based on the ceil mode.
int RoundDim(float dim, bool ceil_mode) {
  if (ceil_mode) {
    return std::ceil(dim);
  }
  return std::floor(dim);
}

// the value of [x0, x1, x2] is x[0] + x[1] * 2⁶⁴ + x[2] * 2¹²⁸.
type macState struct {
	// h is the main accumulator. It is to be interpreted modulo 2¹³⁰ - 5, but
	// can grow larger during and after rounds. It must, however, remain below
	// 2 * (2¹³⁰ - 5).
	h [3]uint64
	// r and s are the private key components.
	r [2]uint64
	s [2]uint64
}

type macGeneric struct {
	macState

	buffer [TagSize]byte

	ROUND1(Rb, Rc, Rd, Ra,  3, 22, Rc3)

	MOVM.IA.W (Rtable), [Rc0,Rc1,Rc2,Rc3]
	ROUND1(Ra, Rb, Rc, Rd,  4,	7, Rc0)
	ROUND1(Rd, Ra, Rb, Rc,  5, 12, Rc1)
	ROUND1(Rc, Rd, Ra, Rb,  6, 17, Rc2)
	ROUND1(Rb, Rc, Rd, Ra,  7, 22, Rc3)

	MOVM.IA.W (Rtable), [Rc0,Rc1,Rc2,Rc3]
	ROUND1(Ra, Rb, Rc, Rd,  8,	7, Rc0)
	ROUND1(Rd, Ra, Rb, Rc,  9, 12, Rc1)
	ROUND1(Rc, Rd, Ra, Rb, 10, 17, Rc2)
	ROUND1(Rb, Rc, Rd, Ra, 11, 22, Rc3)

	ROUND2(R4,R5,R6,R7,10,0xd62f105d, 5);
	ROUND2(R7,R4,R5,R6,15, 0x2441453, 9);
	ROUND2(R6,R7,R4,R5, 4,0xd8a1e681,14);
	ROUND2(R5,R6,R7,R4, 9,0xe7d3fbc8,20);
	ROUND2(R4,R5,R6,R7,14,0x21e1cde6, 5);
	ROUND2(R7,R4,R5,R6, 3,0xc33707d6, 9);
	ROUND2(R6,R7,R4,R5, 8,0xf4d50d87,14);
	ROUND2(R5,R6,R7,R4,13,0x455a14ed,20);
	ROUND2(R4,R5,R6,R7, 2,0xa9e3e905, 5);
	ROUND2(R7,R4,R5,R6, 7,0xfcefa3f8, 9);
	ROUND2(R6,R7,R4,R5,12,0x676f02d9,14);

	ROUND2(R4,R5,R22,R3,M15,0xd8a1e681,14);
	ROUND2(R3,R4,R5,R22,M04,0xe7d3fbc8,20);
	ROUND2(R22,R3,R4,R5,M09,0x21e1cde6, 5);
	ROUND2(R5,R22,R3,R4,M14,0xc33707d6, 9);
	ROUND2(R4,R5,R22,R3,M03,0xf4d50d87,14);
	ROUND2(R3,R4,R5,R22,M08,0x455a14ed,20);
	ROUND2(R22,R3,R4,R5,M13,0xa9e3e905, 5);
	ROUND2(R5,R22,R3,R4,M02,0xfcefa3f8, 9);
	ROUND2(R4,R5,R22,R3,M07,0x676f02d9,14);
	ROUND2(R3,R4,R5,R22,M12,0x8d2a4c8a,20);

	ROUND4(R4,R5,R2,R3, 5,0xab9423a7,15);
	ROUND4(R3,R4,R5,R2,12,0xfc93a039,21);
	ROUND4(R2,R3,R4,R5, 3,0x655b59c3, 6);
	ROUND4(R5,R2,R3,R4,10,0x8f0ccc92,10);
	ROUND4(R4,R5,R2,R3, 1,0xffeff47d,15);
	ROUND4(R3,R4,R5,R2, 8,0x85845dd1,21);
	ROUND4(R2,R3,R4,R5,15,0x6fa87e4f, 6);
	ROUND4(R5,R2,R3,R4, 6,0xfe2ce6e0,10);
	ROUND4(R4,R5,R2,R3,13,0xa3014314,15);
	ROUND4(R3,R4,R5,R2, 4,0x4e0811a1,21);
	ROUND4(R2,R3,R4,R5,11,0xf7537e82, 6);