diff options
Diffstat (limited to 'arch/x86/crypto/sha-mb')
| -rw-r--r-- | arch/x86/crypto/sha-mb/sha1_mb_mgr_flush_avx2.S | 327 | ||||
| -rw-r--r-- | arch/x86/crypto/sha-mb/sha1_mb_mgr_init_avx2.c | 64 | ||||
| -rw-r--r-- | arch/x86/crypto/sha-mb/sha1_mb_mgr_submit_avx2.S | 228 |
3 files changed, 619 insertions, 0 deletions
diff --git a/arch/x86/crypto/sha-mb/sha1_mb_mgr_flush_avx2.S b/arch/x86/crypto/sha-mb/sha1_mb_mgr_flush_avx2.S new file mode 100644 index 0000000..85c4e1c --- /dev/null +++ b/arch/x86/crypto/sha-mb/sha1_mb_mgr_flush_avx2.S @@ -0,0 +1,327 @@ +/* + * Flush routine for SHA1 multibuffer + * + * This file is provided under a dual BSD/GPLv2 license. When using or + * redistributing this file, you may do so under either license. + * + * GPL LICENSE SUMMARY + * + * Copyright(c) 2014 Intel Corporation. + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of version 2 of the GNU General Public License as + * published by the Free Software Foundation. + * + * This program is distributed in the hope that it will be useful, but + * WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + * General Public License for more details. + * + * Contact Information: + * James Guilford <james.guilford@intel.com> + * Tim Chen <tim.c.chen@linux.intel.com> + * + * BSD LICENSE + * + * Copyright(c) 2014 Intel Corporation. + * + * 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 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 THE COPYRIGHT HOLDERS AND CONTRIBUTORS + * "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 THE COPYRIGHT + * OWNER 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. + */ +#include <linux/linkage.h> +#include "sha1_mb_mgr_datastruct.S" + + +.extern sha1_x8_avx2 + +# LINUX register definitions +#define arg1 %rdi +#define arg2 %rsi + +# Common definitions +#define state arg1 +#define job arg2 +#define len2 arg2 + +# idx must be a register not clobbered by sha1_x8_avx2 +#define idx %r8 +#define DWORD_idx %r8d + +#define unused_lanes %rbx +#define lane_data %rbx +#define tmp2 %rbx +#define tmp2_w %ebx + +#define job_rax %rax +#define tmp1 %rax +#define size_offset %rax +#define tmp %rax +#define start_offset %rax + +#define tmp3 %arg1 + +#define extra_blocks %arg2 +#define p %arg2 + + +# STACK_SPACE needs to be an odd multiple of 8 +_XMM_SAVE_SIZE = 10*16 +_GPR_SAVE_SIZE = 8*8 +_ALIGN_SIZE = 8 + +_XMM_SAVE = 0 +_GPR_SAVE = _XMM_SAVE + _XMM_SAVE_SIZE +STACK_SPACE = _GPR_SAVE + _GPR_SAVE_SIZE + _ALIGN_SIZE + +.macro LABEL prefix n +\prefix\n\(): +.endm + +.macro JNE_SKIP i +jne skip_\i +.endm + +.altmacro +.macro SET_OFFSET _offset +offset = \_offset +.endm +.noaltmacro + +# JOB* sha1_mb_mgr_flush_avx2(MB_MGR *state) +# arg 1 : rcx : state +ENTRY(sha1_mb_mgr_flush_avx2) + mov %rsp, %r10 + sub $STACK_SPACE, %rsp + and $~31, %rsp + mov %rbx, _GPR_SAVE(%rsp) + mov %r10, _GPR_SAVE+8*1(%rsp) #save rsp + mov %rbp, _GPR_SAVE+8*3(%rsp) + mov %r12, _GPR_SAVE+8*4(%rsp) + mov %r13, _GPR_SAVE+8*5(%rsp) + mov %r14, _GPR_SAVE+8*6(%rsp) + mov %r15, _GPR_SAVE+8*7(%rsp) + + # If bit (32+3) is set, then all lanes are empty + mov _unused_lanes(state), unused_lanes + bt $32+3, unused_lanes + jc return_null + + # find a lane with a non-null job + xor idx, idx + offset = (_ldata + 1 * _LANE_DATA_size + _job_in_lane) + cmpq $0, offset(state) + cmovne one(%rip), idx + offset = (_ldata + 2 * _LANE_DATA_size + _job_in_lane) + cmpq $0, offset(state) + cmovne two(%rip), idx + offset = (_ldata + 3 * _LANE_DATA_size + _job_in_lane) + cmpq $0, offset(state) + cmovne three(%rip), idx + offset = (_ldata + 4 * _LANE_DATA_size + _job_in_lane) + cmpq $0, offset(state) + cmovne four(%rip), idx + offset = (_ldata + 5 * _LANE_DATA_size + _job_in_lane) + cmpq $0, offset(state) + cmovne five(%rip), idx + offset = (_ldata + 6 * _LANE_DATA_size + _job_in_lane) + cmpq $0, offset(state) + cmovne six(%rip), idx + offset = (_ldata + 7 * _LANE_DATA_size + _job_in_lane) + cmpq $0, offset(state) + cmovne seven(%rip), idx + + # copy idx to empty lanes +copy_lane_data: + offset = (_args + _data_ptr) + mov offset(state,idx,8), tmp + + I = 0 +.rep 8 + offset = (_ldata + I * _LANE_DATA_size + _job_in_lane) + cmpq $0, offset(state) +.altmacro + JNE_SKIP %I + offset = (_args + _data_ptr + 8*I) + mov tmp, offset(state) + offset = (_lens + 4*I) + movl $0xFFFFFFFF, offset(state) +LABEL skip_ %I + I = (I+1) +.noaltmacro +.endr + + # Find min length + vmovdqa _lens+0*16(state), %xmm0 + vmovdqa _lens+1*16(state), %xmm1 + + vpminud %xmm1, %xmm0, %xmm2 # xmm2 has {D,C,B,A} + vpalignr $8, %xmm2, %xmm3, %xmm3 # xmm3 has {x,x,D,C} + vpminud %xmm3, %xmm2, %xmm2 # xmm2 has {x,x,E,F} + vpalignr $4, %xmm2, %xmm3, %xmm3 # xmm3 has {x,x,x,E} + vpminud %xmm3, %xmm2, %xmm2 # xmm2 has min value in low dword + + vmovd %xmm2, DWORD_idx + mov idx, len2 + and $0xF, idx + shr $4, len2 + jz len_is_0 + + vpand clear_low_nibble(%rip), %xmm2, %xmm2 + vpshufd $0, %xmm2, %xmm2 + + vpsubd %xmm2, %xmm0, %xmm0 + vpsubd %xmm2, %xmm1, %xmm1 + + vmovdqa %xmm0, _lens+0*16(state) + vmovdqa %xmm1, _lens+1*16(state) + + # "state" and "args" are the same address, arg1 + # len is arg2 + call sha1_x8_avx2 + # state and idx are intact + + +len_is_0: + # process completed job "idx" + imul $_LANE_DATA_size, idx, lane_data + lea _ldata(state, lane_data), lane_data + + mov _job_in_lane(lane_data), job_rax + movq $0, _job_in_lane(lane_data) + movl $STS_COMPLETED, _status(job_rax) + mov _unused_lanes(state), unused_lanes + shl $4, unused_lanes + or idx, unused_lanes + mov unused_lanes, _unused_lanes(state) + + movl $0xFFFFFFFF, _lens(state, idx, 4) + + vmovd _args_digest(state , idx, 4) , %xmm0 + vpinsrd $1, _args_digest+1*32(state, idx, 4), %xmm0, %xmm0 + vpinsrd $2, _args_digest+2*32(state, idx, 4), %xmm0, %xmm0 + vpinsrd $3, _args_digest+3*32(state, idx, 4), %xmm0, %xmm0 + movl _args_digest+4*32(state, idx, 4), tmp2_w + + vmovdqu %xmm0, _result_digest(job_rax) + offset = (_result_digest + 1*16) + mov tmp2_w, offset(job_rax) + +return: + + mov _GPR_SAVE(%rsp), %rbx + mov _GPR_SAVE+8*1(%rsp), %r10 #saved rsp + mov _GPR_SAVE+8*3(%rsp), %rbp + mov _GPR_SAVE+8*4(%rsp), %r12 + mov _GPR_SAVE+8*5(%rsp), %r13 + mov _GPR_SAVE+8*6(%rsp), %r14 + mov _GPR_SAVE+8*7(%rsp), %r15 + mov %r10, %rsp + + ret + +return_null: + xor job_rax, job_rax + jmp return +ENDPROC(sha1_mb_mgr_flush_avx2) + + +################################################################# + +.align 16 +ENTRY(sha1_mb_mgr_get_comp_job_avx2) + push %rbx + + ## if bit 32+3 is set, then all lanes are empty + mov _unused_lanes(state), unused_lanes + bt $(32+3), unused_lanes + jc .return_null + + # Find min length + vmovdqa _lens(state), %xmm0 + vmovdqa _lens+1*16(state), %xmm1 + + vpminud %xmm1, %xmm0, %xmm2 # xmm2 has {D,C,B,A} + vpalignr $8, %xmm2, %xmm3, %xmm3 # xmm3 has {x,x,D,C} + vpminud %xmm3, %xmm2, %xmm2 # xmm2 has {x,x,E,F} + vpalignr $4, %xmm2, %xmm3, %xmm3 # xmm3 has {x,x,x,E} + vpminud %xmm3, %xmm2, %xmm2 # xmm2 has min value in low dword + + vmovd %xmm2, DWORD_idx + test $~0xF, idx + jnz .return_null + + # process completed job "idx" + imul $_LANE_DATA_size, idx, lane_data + lea _ldata(state, lane_data), lane_data + + mov _job_in_lane(lane_data), job_rax + movq $0, _job_in_lane(lane_data) + movl $STS_COMPLETED, _status(job_rax) + mov _unused_lanes(state), unused_lanes + shl $4, unused_lanes + or idx, unused_lanes + mov unused_lanes, _unused_lanes(state) + + movl $0xFFFFFFFF, _lens(state, idx, 4) + + vmovd _args_digest(state, idx, 4), %xmm0 + vpinsrd $1, _args_digest+1*32(state, idx, 4), %xmm0, %xmm0 + vpinsrd $2, _args_digest+2*32(state, idx, 4), %xmm0, %xmm0 + vpinsrd $3, _args_digest+3*32(state, idx, 4), %xmm0, %xmm0 + movl _args_digest+4*32(state, idx, 4), tmp2_w + + vmovdqu %xmm0, _result_digest(job_rax) + movl tmp2_w, _result_digest+1*16(job_rax) + + pop %rbx + + ret + +.return_null: + xor job_rax, job_rax + pop %rbx + ret +ENDPROC(sha1_mb_mgr_get_comp_job_avx2) + +.data + +.align 16 +clear_low_nibble: +.octa 0x000000000000000000000000FFFFFFF0 +one: +.quad 1 +two: +.quad 2 +three: +.quad 3 +four: +.quad 4 +five: +.quad 5 +six: +.quad 6 +seven: +.quad 7 diff --git a/arch/x86/crypto/sha-mb/sha1_mb_mgr_init_avx2.c b/arch/x86/crypto/sha-mb/sha1_mb_mgr_init_avx2.c new file mode 100644 index 0000000..4ca7e16 --- /dev/null +++ b/arch/x86/crypto/sha-mb/sha1_mb_mgr_init_avx2.c @@ -0,0 +1,64 @@ +/* + * Initialization code for multi buffer SHA1 algorithm for AVX2 + * + * This file is provided under a dual BSD/GPLv2 license. When using or + * redistributing this file, you may do so under either license. + * + * GPL LICENSE SUMMARY + * + * Copyright(c) 2014 Intel Corporation. + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of version 2 of the GNU General Public License as + * published by the Free Software Foundation. + * + * This program is distributed in the hope that it will be useful, but + * WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + * General Public License for more details. + * + * Contact Information: + * Tim Chen <tim.c.chen@linux.intel.com> + * + * BSD LICENSE + * + * Copyright(c) 2014 Intel Corporation. + * + * 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 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 THE COPYRIGHT HOLDERS AND CONTRIBUTORS + * "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 THE COPYRIGHT + * OWNER 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. + */ + +#include "sha_mb_mgr.h" + +void sha1_mb_mgr_init_avx2(struct sha1_mb_mgr *state) +{ + unsigned int j; + state->unused_lanes = 0xF76543210; + for (j = 0; j < 8; j++) { + state->lens[j] = 0xFFFFFFFF; + state->ldata[j].job_in_lane = NULL; + } +} diff --git a/arch/x86/crypto/sha-mb/sha1_mb_mgr_submit_avx2.S b/arch/x86/crypto/sha-mb/sha1_mb_mgr_submit_avx2.S new file mode 100644 index 0000000..2ab9560 --- /dev/null +++ b/arch/x86/crypto/sha-mb/sha1_mb_mgr_submit_avx2.S @@ -0,0 +1,228 @@ +/* + * Buffer submit code for multi buffer SHA1 algorithm + * + * This file is provided under a dual BSD/GPLv2 license. When using or + * redistributing this file, you may do so under either license. + * + * GPL LICENSE SUMMARY + * + * Copyright(c) 2014 Intel Corporation. + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of version 2 of the GNU General Public License as + * published by the Free Software Foundation. + * + * This program is distributed in the hope that it will be useful, but + * WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + * General Public License for more details. + * + * Contact Information: + * James Guilford <james.guilford@intel.com> + * Tim Chen <tim.c.chen@linux.intel.com> + * + * BSD LICENSE + * + * Copyright(c) 2014 Intel Corporation. + * + * 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 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 THE COPYRIGHT HOLDERS AND CONTRIBUTORS + * "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 THE COPYRIGHT + * OWNER 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. + */ + +#include <linux/linkage.h> +#include "sha1_mb_mgr_datastruct.S" + + +.extern sha1_x8_avx + +# LINUX register definitions +arg1 = %rdi +arg2 = %rsi +size_offset = %rcx +tmp2 = %rcx +extra_blocks = %rdx + +# Common definitions +#define state arg1 +#define job %rsi +#define len2 arg2 +#define p2 arg2 + +# idx must be a register not clobberred by sha1_x8_avx2 +idx = %r8 +DWORD_idx = %r8d +last_len = %r8 + +p = %r11 +start_offset = %r11 + +unused_lanes = %rbx +BYTE_unused_lanes = %bl + +job_rax = %rax +len = %rax +DWORD_len = %eax + +lane = %rbp +tmp3 = %rbp + +tmp = %r9 +DWORD_tmp = %r9d + +lane_data = %r10 + +# STACK_SPACE needs to be an odd multiple of 8 +STACK_SPACE = 8*8 + 16*10 + 8 + +# JOB* submit_mb_mgr_submit_avx2(MB_MGR *state, job_sha1 *job) +# arg 1 : rcx : state +# arg 2 : rdx : job +ENTRY(sha1_mb_mgr_submit_avx2) + + mov %rsp, %r10 + sub $STACK_SPACE, %rsp + and $~31, %rsp + + mov %rbx, (%rsp) + mov %r10, 8*2(%rsp) #save old rsp + mov %rbp, 8*3(%rsp) + mov %r12, 8*4(%rsp) + mov %r13, 8*5(%rsp) + mov %r14, 8*6(%rsp) + mov %r15, 8*7(%rsp) + + mov _unused_lanes(state), unused_lanes + mov unused_lanes, lane + and $0xF, lane + shr $4, unused_lanes + imul $_LANE_DATA_size, lane, lane_data + movl $STS_BEING_PROCESSED, _status(job) + lea _ldata(state, lane_data), lane_data + mov unused_lanes, _unused_lanes(state) + movl _len(job), DWORD_len + + mov job, _job_in_lane(lane_data) + shl $4, len + or lane, len + + movl DWORD_len, _lens(state , lane, 4) + + # Load digest words from result_digest + vmovdqu _result_digest(job), %xmm0 + mov _result_digest+1*16(job), DWORD_tmp + vmovd %xmm0, _args_digest(state, lane, 4) + vpextrd $1, %xmm0, _args_digest+1*32(state , lane, 4) + vpextrd $2, %xmm0, _args_digest+2*32(state , lane, 4) + vpextrd $3, %xmm0, _args_digest+3*32(state , lane, 4) + movl DWORD_tmp, _args_digest+4*32(state , lane, 4) + + mov _buffer(job), p + mov p, _args_data_ptr(state, lane, 8) + + cmp $0xF, unused_lanes + jne return_null + +start_loop: + # Find min length + vmovdqa _lens(state), %xmm0 + vmovdqa _lens+1*16(state), %xmm1 + + vpminud %xmm1, %xmm0, %xmm2 # xmm2 has {D,C,B,A} + vpalignr $8, %xmm2, %xmm3, %xmm3 # xmm3 has {x,x,D,C} + vpminud %xmm3, %xmm2, %xmm2 # xmm2 has {x,x,E,F} + vpalignr $4, %xmm2, %xmm3, %xmm3 # xmm3 has {x,x,x,E} + vpminud %xmm3, %xmm2, %xmm2 # xmm2 has min value in low dword + + vmovd %xmm2, DWORD_idx + mov idx, len2 + and $0xF, idx + shr $4, len2 + jz len_is_0 + + vpand clear_low_nibble(%rip), %xmm2, %xmm2 + vpshufd $0, %xmm2, %xmm2 + + vpsubd %xmm2, %xmm0, %xmm0 + vpsubd %xmm2, %xmm1, %xmm1 + + vmovdqa %xmm0, _lens + 0*16(state) + vmovdqa %xmm1, _lens + 1*16(state) + + + # "state" and "args" are the same address, arg1 + # len is arg2 + call sha1_x8_avx2 + + # state and idx are intact + +len_is_0: + # process completed job "idx" + imul $_LANE_DATA_size, idx, lane_data + lea _ldata(state, lane_data), lane_data + + mov _job_in_lane(lane_data), job_rax + mov _unused_lanes(state), unused_lanes + movq $0, _job_in_lane(lane_data) + movl $STS_COMPLETED, _status(job_rax) + shl $4, unused_lanes + or idx, unused_lanes + mov unused_lanes, _unused_lanes(state) + + movl $0xFFFFFFFF, _lens(state, idx, 4) + + vmovd _args_digest(state, idx, 4), %xmm0 + vpinsrd $1, _args_digest+1*32(state , idx, 4), %xmm0, %xmm0 + vpinsrd $2, _args_digest+2*32(state , idx, 4), %xmm0, %xmm0 + vpinsrd $3, _args_digest+3*32(state , idx, 4), %xmm0, %xmm0 + movl 4*32(state, idx, 4), DWORD_tmp + + vmovdqu %xmm0, _result_digest(job_rax) + movl DWORD_tmp, _result_digest+1*16(job_rax) + +return: + + mov (%rsp), %rbx + mov 8*2(%rsp), %r10 #save old rsp + mov 8*3(%rsp), %rbp + mov 8*4(%rsp), %r12 + mov 8*5(%rsp), %r13 + mov 8*6(%rsp), %r14 + mov 8*7(%rsp), %r15 + mov %r10, %rsp + + ret + +return_null: + xor job_rax, job_rax + jmp return + +ENDPROC(sha1_mb_mgr_submit_avx2) + +.data + +.align 16 +clear_low_nibble: + .octa 0x000000000000000000000000FFFFFFF0 |