VPGATHERDQ X2, 664(X2*8), X7    // ERROR "mask, index, and destination registers should be distinct"
	VPGATHERDQ X2, 664(X7*8), X2    // ERROR "mask, index, and destination registers should be distinct"
	VPGATHERDQ X7, 664(X2*8), X2    // ERROR "mask, index, and destination registers should be distinct"
	// Non-X0 for Yxr0 should produce an error

		// Test AVX512 suffixes.
		{"VADDPD.A X0, X1, X2", `unknown suffix "A"`},
		{"VADDPD.A.A X0, X1, X2", `unknown suffix "A"; duplicate suffix "A"`},
		{"VADDPD.A.A.A X0, X1, X2", `unknown suffix "A"; duplicate suffix "A"`},
		{"VADDPD.A.B X0, X1, X2", `unknown suffix "A"; unknown suffix "B"`},
		{"VADDPD.Z.A X0, X1, X2", `Z suffix should be the last; unknown suffix "A"`},
		{"VADDPD.Z.Z X0, X1, X2", `Z suffix should be the last; duplicate suffix "Z"`},

      int result = BigIntegerMath.log2(x, HALF_UP);
      BigInteger x2 = x.pow(2);
      // x^2 < 2^(2 * result + 1), or else we would have rounded up
      assertTrue(ZERO.setBit(2 * result + 1).compareTo(x2) > 0);
      // x^2 >= 2^(2 * result - 1), or else we would have rounded down
      assertTrue(result == 0 || ZERO.setBit(2 * result - 1).compareTo(x2) <= 0);
    }
  }

  public void testLog2HalfDown() {

	ADDSD (R11), X2                         // f2410f5813
	ADDSD X2, X2                            // f20f58d2
	ADDSD X11, X2                           // f2410f58d3
	ADDSD (BX), X11                         // f2440f581b
	ADDSD (R11), X11                        // f2450f581b
	ADDSD X2, X11                           // f2440f58da
	ADDSD X11, X11                          // f2450f58db

     * must not both be identical to the values given in the first mapping. If only the {@code x}
     * values are identical, the transformation is vertical. If only the {@code y} values are
     * identical, the transformation is horizontal (i.e. the slope is zero).
     */
    public LinearTransformation and(double x2, double y2) {

	XVSRLB		$7, X2, X1	// 413c3077
	XVSRLB		$5, X2		// 42343077
	XVSRLH		$0, X2, X1	// 41403077
	XVSRLH		$15, X2, X1	// 417c3077
	XVSRLH		$9, X2		// 42643077
	XVSRLW		$0, X2, X1	// 41803077
	XVSRLW		$31, X2, X1	// 41fc3077
	XVSRLW		$14, X2		// 42b83077
	XVSRLV		$0, X2, X1	// 41003177
	XVSRLV		$63, X2, X1	// 41fc3177
	XVSRLV		$45, X2		// 42b43177
	XVSRAB		$0, X2, X1	// 41203477
	XVSRAB		$7, X2, X1	// 413c3477

	SHA256MSG1 X2, X2        // 0f38ccd2
	SHA256MSG1 X11, X2       // 410f38ccd3
	SHA256MSG1 (BX), X11     // 440f38cc1b
	SHA256MSG1 (R11), X11    // 450f38cc1b
	SHA256MSG1 X2, X11       // 440f38ccda
	SHA256MSG1 X11, X11      // 450f38ccdb
	SHA256MSG2 (BX), X2      // 0f38cd13
	SHA256MSG2 (R11), X2     // 410f38cd13
	SHA256MSG2 X2, X2        // 0f38cdd2
	SHA256MSG2 X11, X2       // 410f38cdd3

	VRCP28SD X25, X14, K4, X2                          // 62928d0ccbd1
	VRCP28SD X11, X14, K4, X2                          // 62d28d0ccbd3
	VRCP28SD X17, X14, K4, X2                          // 62b28d0ccbd1
	VRCP28SD X25, X0, K4, X2                           // 6292fd0ccbd1
	VRCP28SD X11, X0, K4, X2                           // 62d2fd0ccbd3
	VRCP28SD X17, X0, K4, X2                           // 62b2fd0ccbd1

	VPDPWSSD X2, X2, K3, X18                           // 62e26d0b52d2
	VPDPWSSD X27, X2, K3, X18                          // 62826d0b52d3
	VPDPWSSD X26, X2, K3, X18                          // 62826d0b52d2
	VPDPWSSD (SI), X2, K3, X18                         // 62e26d0b5216
	VPDPWSSD 7(SI)(DI*2), X2, K3, X18                  // 62e26d0b52947e07000000
	VPDPWSSD X2, X24, K3, X18                          // 62e23d0352d2

	VPOPCNTW 99(R15), K3, X23                          // 62c2fd0b54bf63000000
	VPOPCNTW X20, K3, X2                               // 62b2fd0b54d4
	VPOPCNTW X5, K3, X2                                // 62f2fd0b54d5
	VPOPCNTW X25, K3, X2                               // 6292fd0b54d1
	VPOPCNTW (CX), K3, X2                              // 62f2fd0b5411
	VPOPCNTW 99(R15), K3, X2                           // 62d2fd0b549763000000