crct10dif-pcl-asm_64.S 15.6 KB
Newer Older
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 328 329 330 331 332 333 334 335 336 337 338 339 340 341 342 343 344 345 346 347 348 349 350 351 352 353 354 355 356 357 358 359 360 361 362 363 364 365 366 367 368 369 370 371 372 373 374 375 376 377 378 379 380 381 382 383 384 385 386 387 388 389 390 391 392 393 394 395 396 397 398 399 400 401 402 403 404 405 406 407 408 409 410 411 412 413 414 415 416 417 418 419 420 421 422 423 424 425 426 427 428 429 430 431 432 433 434 435 436 437 438 439 440 441 442 443 444 445 446 447 448 449 450 451 452 453 454 455 456 457 458 459 460 461 462 463 464 465 466 467 468 469 470 471 472 473 474 475 476 477 478 479 480 481 482 483 484 485 486 487 488 489 490 491 492 493 494 495 496 497 498 499 500 501 502 503 504 505 506 507 508 509 510 511 512 513 514 515 516 517 518 519 520 521 522 523 524 525 526 527 528 529 530 531 532 533 534 535 536 537 538 539 540 541 542 543 544 545 546 547 548 549 550 551 552 553 554 555 556 557 558 559 560 561 562 563 564 565 566 567 568 569 570 571 572 573 574 575 576 577 578 579 580 581 582 583 584 585 586 587 588 589 590 591 592 593 594 595 596 597 598 599 600 601 602 603 604 605 606 607 608 609 610 611 612 613 614 615 616 617 618 619 620 621 622 623 624 625 626 627 628 629 630 631 632 633 634 635 636 637 638 639 640 641 642 643
########################################################################
# Implement fast CRC-T10DIF computation with SSE and PCLMULQDQ instructions
#
# Copyright (c) 2013, Intel Corporation
#
# Authors:
#     Erdinc Ozturk <erdinc.ozturk@intel.com>
#     Vinodh Gopal <vinodh.gopal@intel.com>
#     James Guilford <james.guilford@intel.com>
#     Tim Chen <tim.c.chen@linux.intel.com>
#
# This software is available to you under a choice of one of two
# licenses.  You may choose to be licensed under the terms of the GNU
# General Public License (GPL) Version 2, available from the file
# COPYING in the main directory of this source tree, or the
# OpenIB.org BSD license below:
#
# Redistribution and use in source and binary forms, with or without
# modification, are permitted provided that the following conditions are
# met:
#
# * Redistributions of source code must retain the above copyright
#   notice, this list of conditions and the following disclaimer.
#
# * Redistributions in binary form must reproduce the above copyright
#   notice, this list of conditions and the following disclaimer in the
#   documentation and/or other materials provided with the
#   distribution.
#
# * Neither the name of the Intel Corporation nor the names of its
#   contributors may be used to endorse or promote products derived from
#   this software without specific prior written permission.
#
#
# THIS SOFTWARE IS PROVIDED BY INTEL CORPORATION ""AS IS"" AND ANY
# EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
# IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
# PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL INTEL CORPORATION OR
# CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
# EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
# PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
# PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
# LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
# NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
# SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
########################################################################
#       Function API:
#       UINT16 crc_t10dif_pcl(
#               UINT16 init_crc, //initial CRC value, 16 bits
#               const unsigned char *buf, //buffer pointer to calculate CRC on
#               UINT64 len //buffer length in bytes (64-bit data)
#       );
#
#       Reference paper titled "Fast CRC Computation for Generic
#	Polynomials Using PCLMULQDQ Instruction"
#       URL: http://www.intel.com/content/dam/www/public/us/en/documents
#  /white-papers/fast-crc-computation-generic-polynomials-pclmulqdq-paper.pdf
#
#

#include <linux/linkage.h>

.text

#define        arg1 %rdi
#define        arg2 %rsi
#define        arg3 %rdx

#define        arg1_low32 %edi

ENTRY(crc_t10dif_pcl)
.align 16

	# adjust the 16-bit initial_crc value, scale it to 32 bits
	shl	$16, arg1_low32

	# Allocate Stack Space
	mov     %rsp, %rcx
	sub	$16*2, %rsp
	# align stack to 16 byte boundary
	and     $~(0x10 - 1), %rsp

	# check if smaller than 256
	cmp	$256, arg3

	# for sizes less than 128, we can't fold 64B at a time...
	jl	_less_than_128


	# load the initial crc value
	movd	arg1_low32, %xmm10	# initial crc

	# crc value does not need to be byte-reflected, but it needs
	# to be moved to the high part of the register.
	# because data will be byte-reflected and will align with
	# initial crc at correct place.
	pslldq	$12, %xmm10

	movdqa  SHUF_MASK(%rip), %xmm11
	# receive the initial 64B data, xor the initial crc value
	movdqu	16*0(arg2), %xmm0
	movdqu	16*1(arg2), %xmm1
	movdqu	16*2(arg2), %xmm2
	movdqu	16*3(arg2), %xmm3
	movdqu	16*4(arg2), %xmm4
	movdqu	16*5(arg2), %xmm5
	movdqu	16*6(arg2), %xmm6
	movdqu	16*7(arg2), %xmm7

	pshufb	%xmm11, %xmm0
	# XOR the initial_crc value
	pxor	%xmm10, %xmm0
	pshufb	%xmm11, %xmm1
	pshufb	%xmm11, %xmm2
	pshufb	%xmm11, %xmm3
	pshufb	%xmm11, %xmm4
	pshufb	%xmm11, %xmm5
	pshufb	%xmm11, %xmm6
	pshufb	%xmm11, %xmm7

	movdqa	rk3(%rip), %xmm10	#xmm10 has rk3 and rk4
					#imm value of pclmulqdq instruction
					#will determine which constant to use

	#################################################################
	# we subtract 256 instead of 128 to save one instruction from the loop
	sub	$256, arg3

	# at this section of the code, there is 64*x+y (0<=y<64) bytes of
	# buffer. The _fold_64_B_loop will fold 64B at a time
	# until we have 64+y Bytes of buffer


	# fold 64B at a time. This section of the code folds 4 xmm
	# registers in parallel
_fold_64_B_loop:

	# update the buffer pointer
	add	$128, arg2		#    buf += 64#

	movdqu	16*0(arg2), %xmm9
	movdqu	16*1(arg2), %xmm12
	pshufb	%xmm11, %xmm9
	pshufb	%xmm11, %xmm12
	movdqa	%xmm0, %xmm8
	movdqa	%xmm1, %xmm13
	pclmulqdq	$0x0 , %xmm10, %xmm0
	pclmulqdq	$0x11, %xmm10, %xmm8
	pclmulqdq	$0x0 , %xmm10, %xmm1
	pclmulqdq	$0x11, %xmm10, %xmm13
	pxor	%xmm9 , %xmm0
	xorps	%xmm8 , %xmm0
	pxor	%xmm12, %xmm1
	xorps	%xmm13, %xmm1

	movdqu	16*2(arg2), %xmm9
	movdqu	16*3(arg2), %xmm12
	pshufb	%xmm11, %xmm9
	pshufb	%xmm11, %xmm12
	movdqa	%xmm2, %xmm8
	movdqa	%xmm3, %xmm13
	pclmulqdq	$0x0, %xmm10, %xmm2
	pclmulqdq	$0x11, %xmm10, %xmm8
	pclmulqdq	$0x0, %xmm10, %xmm3
	pclmulqdq	$0x11, %xmm10, %xmm13
	pxor	%xmm9 , %xmm2
	xorps	%xmm8 , %xmm2
	pxor	%xmm12, %xmm3
	xorps	%xmm13, %xmm3

	movdqu	16*4(arg2), %xmm9
	movdqu	16*5(arg2), %xmm12
	pshufb	%xmm11, %xmm9
	pshufb	%xmm11, %xmm12
	movdqa	%xmm4, %xmm8
	movdqa	%xmm5, %xmm13
	pclmulqdq	$0x0,  %xmm10, %xmm4
	pclmulqdq	$0x11, %xmm10, %xmm8
	pclmulqdq	$0x0,  %xmm10, %xmm5
	pclmulqdq	$0x11, %xmm10, %xmm13
	pxor	%xmm9 ,  %xmm4
	xorps	%xmm8 ,  %xmm4
	pxor	%xmm12,  %xmm5
	xorps	%xmm13,  %xmm5

	movdqu	16*6(arg2), %xmm9
	movdqu	16*7(arg2), %xmm12
	pshufb	%xmm11, %xmm9
	pshufb	%xmm11, %xmm12
	movdqa	%xmm6 , %xmm8
	movdqa	%xmm7 , %xmm13
	pclmulqdq	$0x0 , %xmm10, %xmm6
	pclmulqdq	$0x11, %xmm10, %xmm8
	pclmulqdq	$0x0 , %xmm10, %xmm7
	pclmulqdq	$0x11, %xmm10, %xmm13
	pxor	%xmm9 , %xmm6
	xorps	%xmm8 , %xmm6
	pxor	%xmm12, %xmm7
	xorps	%xmm13, %xmm7

	sub	$128, arg3

	# check if there is another 64B in the buffer to be able to fold
	jge	_fold_64_B_loop
	##################################################################


	add	$128, arg2
	# at this point, the buffer pointer is pointing at the last y Bytes
	# of the buffer the 64B of folded data is in 4 of the xmm
	# registers: xmm0, xmm1, xmm2, xmm3


	# fold the 8 xmm registers to 1 xmm register with different constants

	movdqa	rk9(%rip), %xmm10
	movdqa	%xmm0, %xmm8
	pclmulqdq	$0x11, %xmm10, %xmm0
	pclmulqdq	$0x0 , %xmm10, %xmm8
	pxor	%xmm8, %xmm7
	xorps	%xmm0, %xmm7

	movdqa	rk11(%rip), %xmm10
	movdqa	%xmm1, %xmm8
	pclmulqdq	 $0x11, %xmm10, %xmm1
	pclmulqdq	 $0x0 , %xmm10, %xmm8
	pxor	%xmm8, %xmm7
	xorps	%xmm1, %xmm7

	movdqa	rk13(%rip), %xmm10
	movdqa	%xmm2, %xmm8
	pclmulqdq	 $0x11, %xmm10, %xmm2
	pclmulqdq	 $0x0 , %xmm10, %xmm8
	pxor	%xmm8, %xmm7
	pxor	%xmm2, %xmm7

	movdqa	rk15(%rip), %xmm10
	movdqa	%xmm3, %xmm8
	pclmulqdq	$0x11, %xmm10, %xmm3
	pclmulqdq	$0x0 , %xmm10, %xmm8
	pxor	%xmm8, %xmm7
	xorps	%xmm3, %xmm7

	movdqa	rk17(%rip), %xmm10
	movdqa	%xmm4, %xmm8
	pclmulqdq	$0x11, %xmm10, %xmm4
	pclmulqdq	$0x0 , %xmm10, %xmm8
	pxor	%xmm8, %xmm7
	pxor	%xmm4, %xmm7

	movdqa	rk19(%rip), %xmm10
	movdqa	%xmm5, %xmm8
	pclmulqdq	$0x11, %xmm10, %xmm5
	pclmulqdq	$0x0 , %xmm10, %xmm8
	pxor	%xmm8, %xmm7
	xorps	%xmm5, %xmm7

	movdqa	rk1(%rip), %xmm10	#xmm10 has rk1 and rk2
					#imm value of pclmulqdq instruction
					#will determine which constant to use
	movdqa	%xmm6, %xmm8
	pclmulqdq	$0x11, %xmm10, %xmm6
	pclmulqdq	$0x0 , %xmm10, %xmm8
	pxor	%xmm8, %xmm7
	pxor	%xmm6, %xmm7


	# instead of 64, we add 48 to the loop counter to save 1 instruction
	# from the loop instead of a cmp instruction, we use the negative
	# flag with the jl instruction
	add	$128-16, arg3
	jl	_final_reduction_for_128

	# now we have 16+y bytes left to reduce. 16 Bytes is in register xmm7
	# and the rest is in memory. We can fold 16 bytes at a time if y>=16
	# continue folding 16B at a time

_16B_reduction_loop:
	movdqa	%xmm7, %xmm8
	pclmulqdq	$0x11, %xmm10, %xmm7
	pclmulqdq	$0x0 , %xmm10, %xmm8
	pxor	%xmm8, %xmm7
	movdqu	(arg2), %xmm0
	pshufb	%xmm11, %xmm0
	pxor	%xmm0 , %xmm7
	add	$16, arg2
	sub	$16, arg3
	# instead of a cmp instruction, we utilize the flags with the
	# jge instruction equivalent of: cmp arg3, 16-16
	# check if there is any more 16B in the buffer to be able to fold
	jge	_16B_reduction_loop

	#now we have 16+z bytes left to reduce, where 0<= z < 16.
	#first, we reduce the data in the xmm7 register


_final_reduction_for_128:
	# check if any more data to fold. If not, compute the CRC of
	# the final 128 bits
	add	$16, arg3
	je	_128_done

	# here we are getting data that is less than 16 bytes.
	# since we know that there was data before the pointer, we can
	# offset the input pointer before the actual point, to receive
	# exactly 16 bytes. after that the registers need to be adjusted.
_get_last_two_xmms:
	movdqa	%xmm7, %xmm2

	movdqu	-16(arg2, arg3), %xmm1
	pshufb	%xmm11, %xmm1

	# get rid of the extra data that was loaded before
	# load the shift constant
	lea	pshufb_shf_table+16(%rip), %rax
	sub	arg3, %rax
	movdqu	(%rax), %xmm0

	# shift xmm2 to the left by arg3 bytes
	pshufb	%xmm0, %xmm2

	# shift xmm7 to the right by 16-arg3 bytes
	pxor	mask1(%rip), %xmm0
	pshufb	%xmm0, %xmm7
	pblendvb	%xmm2, %xmm1	#xmm0 is implicit

	# fold 16 Bytes
	movdqa	%xmm1, %xmm2
	movdqa	%xmm7, %xmm8
	pclmulqdq	$0x11, %xmm10, %xmm7
	pclmulqdq	$0x0 , %xmm10, %xmm8
	pxor	%xmm8, %xmm7
	pxor	%xmm2, %xmm7

_128_done:
	# compute crc of a 128-bit value
	movdqa	rk5(%rip), %xmm10	# rk5 and rk6 in xmm10
	movdqa	%xmm7, %xmm0

	#64b fold
	pclmulqdq	$0x1, %xmm10, %xmm7
	pslldq	$8   ,  %xmm0
	pxor	%xmm0,  %xmm7

	#32b fold
	movdqa	%xmm7, %xmm0

	pand	mask2(%rip), %xmm0

	psrldq	$12, %xmm7
	pclmulqdq	$0x10, %xmm10, %xmm7
	pxor	%xmm0, %xmm7

	#barrett reduction
_barrett:
	movdqa	rk7(%rip), %xmm10	# rk7 and rk8 in xmm10
	movdqa	%xmm7, %xmm0
	pclmulqdq	$0x01, %xmm10, %xmm7
	pslldq	$4, %xmm7
	pclmulqdq	$0x11, %xmm10, %xmm7

	pslldq	$4, %xmm7
	pxor	%xmm0, %xmm7
	pextrd	$1, %xmm7, %eax

_cleanup:
	# scale the result back to 16 bits
	shr	$16, %eax
	mov     %rcx, %rsp
	ret

########################################################################

.align 16
_less_than_128:

	# check if there is enough buffer to be able to fold 16B at a time
	cmp	$32, arg3
	jl	_less_than_32
	movdqa  SHUF_MASK(%rip), %xmm11

	# now if there is, load the constants
	movdqa	rk1(%rip), %xmm10	# rk1 and rk2 in xmm10

	movd	arg1_low32, %xmm0	# get the initial crc value
	pslldq	$12, %xmm0	# align it to its correct place
	movdqu	(arg2), %xmm7	# load the plaintext
	pshufb	%xmm11, %xmm7	# byte-reflect the plaintext
	pxor	%xmm0, %xmm7


	# update the buffer pointer
	add	$16, arg2

	# update the counter. subtract 32 instead of 16 to save one
	# instruction from the loop
	sub	$32, arg3

	jmp	_16B_reduction_loop


.align 16
_less_than_32:
	# mov initial crc to the return value. this is necessary for
	# zero-length buffers.
	mov	arg1_low32, %eax
	test	arg3, arg3
	je	_cleanup

	movdqa  SHUF_MASK(%rip), %xmm11

	movd	arg1_low32, %xmm0	# get the initial crc value
	pslldq	$12, %xmm0	# align it to its correct place

	cmp	$16, arg3
	je	_exact_16_left
	jl	_less_than_16_left

	movdqu	(arg2), %xmm7	# load the plaintext
	pshufb	%xmm11, %xmm7	# byte-reflect the plaintext
	pxor	%xmm0 , %xmm7	# xor the initial crc value
	add	$16, arg2
	sub	$16, arg3
	movdqa	rk1(%rip), %xmm10	# rk1 and rk2 in xmm10
	jmp	_get_last_two_xmms


.align 16
_less_than_16_left:
	# use stack space to load data less than 16 bytes, zero-out
	# the 16B in memory first.

	pxor	%xmm1, %xmm1
	mov	%rsp, %r11
	movdqa	%xmm1, (%r11)

	cmp	$4, arg3
	jl	_only_less_than_4

	# backup the counter value
	mov	arg3, %r9
	cmp	$8, arg3
	jl	_less_than_8_left

	# load 8 Bytes
	mov	(arg2), %rax
	mov	%rax, (%r11)
	add	$8, %r11
	sub	$8, arg3
	add	$8, arg2
_less_than_8_left:

	cmp	$4, arg3
	jl	_less_than_4_left

	# load 4 Bytes
	mov	(arg2), %eax
	mov	%eax, (%r11)
	add	$4, %r11
	sub	$4, arg3
	add	$4, arg2
_less_than_4_left:

	cmp	$2, arg3
	jl	_less_than_2_left

	# load 2 Bytes
	mov	(arg2), %ax
	mov	%ax, (%r11)
	add	$2, %r11
	sub	$2, arg3
	add	$2, arg2
_less_than_2_left:
	cmp     $1, arg3
        jl      _zero_left

	# load 1 Byte
	mov	(arg2), %al
	mov	%al, (%r11)
_zero_left:
	movdqa	(%rsp), %xmm7
	pshufb	%xmm11, %xmm7
	pxor	%xmm0 , %xmm7	# xor the initial crc value

	# shl r9, 4
	lea	pshufb_shf_table+16(%rip), %rax
	sub	%r9, %rax
	movdqu	(%rax), %xmm0
	pxor	mask1(%rip), %xmm0

	pshufb	%xmm0, %xmm7
	jmp	_128_done

.align 16
_exact_16_left:
	movdqu	(arg2), %xmm7
	pshufb	%xmm11, %xmm7
	pxor	%xmm0 , %xmm7   # xor the initial crc value

	jmp	_128_done

_only_less_than_4:
	cmp	$3, arg3
	jl	_only_less_than_3

	# load 3 Bytes
	mov	(arg2), %al
	mov	%al, (%r11)

	mov	1(arg2), %al
	mov	%al, 1(%r11)

	mov	2(arg2), %al
	mov	%al, 2(%r11)

	movdqa	 (%rsp), %xmm7
	pshufb	 %xmm11, %xmm7
	pxor	 %xmm0 , %xmm7  # xor the initial crc value

	psrldq	$5, %xmm7

	jmp	_barrett
_only_less_than_3:
	cmp	$2, arg3
	jl	_only_less_than_2

	# load 2 Bytes
	mov	(arg2), %al
	mov	%al, (%r11)

	mov	1(arg2), %al
	mov	%al, 1(%r11)

	movdqa	(%rsp), %xmm7
	pshufb	%xmm11, %xmm7
	pxor	%xmm0 , %xmm7   # xor the initial crc value

	psrldq	$6, %xmm7

	jmp	_barrett
_only_less_than_2:

	# load 1 Byte
	mov	(arg2), %al
	mov	%al, (%r11)

	movdqa	(%rsp), %xmm7
	pshufb	%xmm11, %xmm7
	pxor	%xmm0 , %xmm7   # xor the initial crc value

	psrldq	$7, %xmm7

	jmp	_barrett

ENDPROC(crc_t10dif_pcl)

.data

# precomputed constants
# these constants are precomputed from the poly:
# 0x8bb70000 (0x8bb7 scaled to 32 bits)
.align 16
# Q = 0x18BB70000
# rk1 = 2^(32*3) mod Q << 32
# rk2 = 2^(32*5) mod Q << 32
# rk3 = 2^(32*15) mod Q << 32
# rk4 = 2^(32*17) mod Q << 32
# rk5 = 2^(32*3) mod Q << 32
# rk6 = 2^(32*2) mod Q << 32
# rk7 = floor(2^64/Q)
# rk8 = Q
rk1:
.quad 0x2d56000000000000
rk2:
.quad 0x06df000000000000
rk3:
.quad 0x9d9d000000000000
rk4:
.quad 0x7cf5000000000000
rk5:
.quad 0x2d56000000000000
rk6:
.quad 0x1368000000000000
rk7:
.quad 0x00000001f65a57f8
rk8:
.quad 0x000000018bb70000

rk9:
.quad 0xceae000000000000
rk10:
.quad 0xbfd6000000000000
rk11:
.quad 0x1e16000000000000
rk12:
.quad 0x713c000000000000
rk13:
.quad 0xf7f9000000000000
rk14:
.quad 0x80a6000000000000
rk15:
.quad 0x044c000000000000
rk16:
.quad 0xe658000000000000
rk17:
.quad 0xad18000000000000
rk18:
.quad 0xa497000000000000
rk19:
.quad 0x6ee3000000000000
rk20:
.quad 0xe7b5000000000000



mask1:
.octa 0x80808080808080808080808080808080
mask2:
.octa 0x00000000FFFFFFFFFFFFFFFFFFFFFFFF

SHUF_MASK:
.octa 0x000102030405060708090A0B0C0D0E0F

pshufb_shf_table:
# use these values for shift constants for the pshufb instruction
# different alignments result in values as shown:
#	DDQ 0x008f8e8d8c8b8a898887868584838281 # shl 15 (16-1) / shr1
#	DDQ 0x01008f8e8d8c8b8a8988878685848382 # shl 14 (16-3) / shr2
#	DDQ 0x0201008f8e8d8c8b8a89888786858483 # shl 13 (16-4) / shr3
#	DDQ 0x030201008f8e8d8c8b8a898887868584 # shl 12 (16-4) / shr4
#	DDQ 0x04030201008f8e8d8c8b8a8988878685 # shl 11 (16-5) / shr5
#	DDQ 0x0504030201008f8e8d8c8b8a89888786 # shl 10 (16-6) / shr6
#	DDQ 0x060504030201008f8e8d8c8b8a898887 # shl 9  (16-7) / shr7
#	DDQ 0x07060504030201008f8e8d8c8b8a8988 # shl 8  (16-8) / shr8
#	DDQ 0x0807060504030201008f8e8d8c8b8a89 # shl 7  (16-9) / shr9
#	DDQ 0x090807060504030201008f8e8d8c8b8a # shl 6  (16-10) / shr10
#	DDQ 0x0a090807060504030201008f8e8d8c8b # shl 5  (16-11) / shr11
#	DDQ 0x0b0a090807060504030201008f8e8d8c # shl 4  (16-12) / shr12
#	DDQ 0x0c0b0a090807060504030201008f8e8d # shl 3  (16-13) / shr13
#	DDQ 0x0d0c0b0a090807060504030201008f8e # shl 2  (16-14) / shr14
#	DDQ 0x0e0d0c0b0a090807060504030201008f # shl 1  (16-15) / shr15
.octa 0x8f8e8d8c8b8a89888786858483828100
.octa 0x000e0d0c0b0a09080706050403020100