| // |
| // Accelerated CRC-T10DIF using arm64 NEON and Crypto Extensions instructions |
| // |
| // Copyright (C) 2016 Linaro Ltd <ard.biesheuvel@linaro.org> |
| // Copyright (C) 2019 Google LLC <ebiggers@google.com> |
| // |
| // This program is free software; you can redistribute it and/or modify |
| // it under the terms of the GNU General Public License version 2 as |
| // published by the Free Software Foundation. |
| // |
| |
| // Derived from the x86 version: |
| // |
| // 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. |
| // |
| // 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> |
| #include <asm/assembler.h> |
| |
| .text |
| .cpu generic+crypto |
| |
| init_crc .req w19 |
| buf .req x20 |
| len .req x21 |
| fold_consts_ptr .req x22 |
| |
| fold_consts .req v10 |
| |
| ad .req v14 |
| |
| k00_16 .req v15 |
| k32_48 .req v16 |
| |
| t3 .req v17 |
| t4 .req v18 |
| t5 .req v19 |
| t6 .req v20 |
| t7 .req v21 |
| t8 .req v22 |
| t9 .req v23 |
| |
| perm1 .req v24 |
| perm2 .req v25 |
| perm3 .req v26 |
| perm4 .req v27 |
| |
| bd1 .req v28 |
| bd2 .req v29 |
| bd3 .req v30 |
| bd4 .req v31 |
| |
| .macro __pmull_init_p64 |
| .endm |
| |
| .macro __pmull_pre_p64, bd |
| .endm |
| |
| .macro __pmull_init_p8 |
| // k00_16 := 0x0000000000000000_000000000000ffff |
| // k32_48 := 0x00000000ffffffff_0000ffffffffffff |
| movi k32_48.2d, #0xffffffff |
| mov k32_48.h[2], k32_48.h[0] |
| ushr k00_16.2d, k32_48.2d, #32 |
| |
| // prepare the permutation vectors |
| mov_q x5, 0x080f0e0d0c0b0a09 |
| movi perm4.8b, #8 |
| dup perm1.2d, x5 |
| eor perm1.16b, perm1.16b, perm4.16b |
| ushr perm2.2d, perm1.2d, #8 |
| ushr perm3.2d, perm1.2d, #16 |
| ushr perm4.2d, perm1.2d, #24 |
| sli perm2.2d, perm1.2d, #56 |
| sli perm3.2d, perm1.2d, #48 |
| sli perm4.2d, perm1.2d, #40 |
| .endm |
| |
| .macro __pmull_pre_p8, bd |
| tbl bd1.16b, {\bd\().16b}, perm1.16b |
| tbl bd2.16b, {\bd\().16b}, perm2.16b |
| tbl bd3.16b, {\bd\().16b}, perm3.16b |
| tbl bd4.16b, {\bd\().16b}, perm4.16b |
| .endm |
| |
| __pmull_p8_core: |
| .L__pmull_p8_core: |
| ext t4.8b, ad.8b, ad.8b, #1 // A1 |
| ext t5.8b, ad.8b, ad.8b, #2 // A2 |
| ext t6.8b, ad.8b, ad.8b, #3 // A3 |
| |
| pmull t4.8h, t4.8b, fold_consts.8b // F = A1*B |
| pmull t8.8h, ad.8b, bd1.8b // E = A*B1 |
| pmull t5.8h, t5.8b, fold_consts.8b // H = A2*B |
| pmull t7.8h, ad.8b, bd2.8b // G = A*B2 |
| pmull t6.8h, t6.8b, fold_consts.8b // J = A3*B |
| pmull t9.8h, ad.8b, bd3.8b // I = A*B3 |
| pmull t3.8h, ad.8b, bd4.8b // K = A*B4 |
| b 0f |
| |
| .L__pmull_p8_core2: |
| tbl t4.16b, {ad.16b}, perm1.16b // A1 |
| tbl t5.16b, {ad.16b}, perm2.16b // A2 |
| tbl t6.16b, {ad.16b}, perm3.16b // A3 |
| |
| pmull2 t4.8h, t4.16b, fold_consts.16b // F = A1*B |
| pmull2 t8.8h, ad.16b, bd1.16b // E = A*B1 |
| pmull2 t5.8h, t5.16b, fold_consts.16b // H = A2*B |
| pmull2 t7.8h, ad.16b, bd2.16b // G = A*B2 |
| pmull2 t6.8h, t6.16b, fold_consts.16b // J = A3*B |
| pmull2 t9.8h, ad.16b, bd3.16b // I = A*B3 |
| pmull2 t3.8h, ad.16b, bd4.16b // K = A*B4 |
| |
| 0: eor t4.16b, t4.16b, t8.16b // L = E + F |
| eor t5.16b, t5.16b, t7.16b // M = G + H |
| eor t6.16b, t6.16b, t9.16b // N = I + J |
| |
| uzp1 t8.2d, t4.2d, t5.2d |
| uzp2 t4.2d, t4.2d, t5.2d |
| uzp1 t7.2d, t6.2d, t3.2d |
| uzp2 t6.2d, t6.2d, t3.2d |
| |
| // t4 = (L) (P0 + P1) << 8 |
| // t5 = (M) (P2 + P3) << 16 |
| eor t8.16b, t8.16b, t4.16b |
| and t4.16b, t4.16b, k32_48.16b |
| |
| // t6 = (N) (P4 + P5) << 24 |
| // t7 = (K) (P6 + P7) << 32 |
| eor t7.16b, t7.16b, t6.16b |
| and t6.16b, t6.16b, k00_16.16b |
| |
| eor t8.16b, t8.16b, t4.16b |
| eor t7.16b, t7.16b, t6.16b |
| |
| zip2 t5.2d, t8.2d, t4.2d |
| zip1 t4.2d, t8.2d, t4.2d |
| zip2 t3.2d, t7.2d, t6.2d |
| zip1 t6.2d, t7.2d, t6.2d |
| |
| ext t4.16b, t4.16b, t4.16b, #15 |
| ext t5.16b, t5.16b, t5.16b, #14 |
| ext t6.16b, t6.16b, t6.16b, #13 |
| ext t3.16b, t3.16b, t3.16b, #12 |
| |
| eor t4.16b, t4.16b, t5.16b |
| eor t6.16b, t6.16b, t3.16b |
| ret |
| ENDPROC(__pmull_p8_core) |
| |
| .macro __pmull_p8, rq, ad, bd, i |
| .ifnc \bd, fold_consts |
| .err |
| .endif |
| mov ad.16b, \ad\().16b |
| .ifb \i |
| pmull \rq\().8h, \ad\().8b, \bd\().8b // D = A*B |
| .else |
| pmull2 \rq\().8h, \ad\().16b, \bd\().16b // D = A*B |
| .endif |
| |
| bl .L__pmull_p8_core\i |
| |
| eor \rq\().16b, \rq\().16b, t4.16b |
| eor \rq\().16b, \rq\().16b, t6.16b |
| .endm |
| |
| // Fold reg1, reg2 into the next 32 data bytes, storing the result back |
| // into reg1, reg2. |
| .macro fold_32_bytes, p, reg1, reg2 |
| ldp q11, q12, [buf], #0x20 |
| |
| __pmull_\p v8, \reg1, fold_consts, 2 |
| __pmull_\p \reg1, \reg1, fold_consts |
| |
| CPU_LE( rev64 v11.16b, v11.16b ) |
| CPU_LE( rev64 v12.16b, v12.16b ) |
| |
| __pmull_\p v9, \reg2, fold_consts, 2 |
| __pmull_\p \reg2, \reg2, fold_consts |
| |
| CPU_LE( ext v11.16b, v11.16b, v11.16b, #8 ) |
| CPU_LE( ext v12.16b, v12.16b, v12.16b, #8 ) |
| |
| eor \reg1\().16b, \reg1\().16b, v8.16b |
| eor \reg2\().16b, \reg2\().16b, v9.16b |
| eor \reg1\().16b, \reg1\().16b, v11.16b |
| eor \reg2\().16b, \reg2\().16b, v12.16b |
| .endm |
| |
| // Fold src_reg into dst_reg, optionally loading the next fold constants |
| .macro fold_16_bytes, p, src_reg, dst_reg, load_next_consts |
| __pmull_\p v8, \src_reg, fold_consts |
| __pmull_\p \src_reg, \src_reg, fold_consts, 2 |
| .ifnb \load_next_consts |
| ld1 {fold_consts.2d}, [fold_consts_ptr], #16 |
| __pmull_pre_\p fold_consts |
| .endif |
| eor \dst_reg\().16b, \dst_reg\().16b, v8.16b |
| eor \dst_reg\().16b, \dst_reg\().16b, \src_reg\().16b |
| .endm |
| |
| .macro __pmull_p64, rd, rn, rm, n |
| .ifb \n |
| pmull \rd\().1q, \rn\().1d, \rm\().1d |
| .else |
| pmull2 \rd\().1q, \rn\().2d, \rm\().2d |
| .endif |
| .endm |
| |
| .macro crc_t10dif_pmull, p |
| frame_push 4, 128 |
| |
| mov init_crc, w0 |
| mov buf, x1 |
| mov len, x2 |
| |
| __pmull_init_\p |
| |
| // For sizes less than 256 bytes, we can't fold 128 bytes at a time. |
| cmp len, #256 |
| b.lt .Lless_than_256_bytes_\@ |
| |
| adr_l fold_consts_ptr, .Lfold_across_128_bytes_consts |
| |
| // Load the first 128 data bytes. Byte swapping is necessary to make |
| // the bit order match the polynomial coefficient order. |
| ldp q0, q1, [buf] |
| ldp q2, q3, [buf, #0x20] |
| ldp q4, q5, [buf, #0x40] |
| ldp q6, q7, [buf, #0x60] |
| add buf, buf, #0x80 |
| CPU_LE( rev64 v0.16b, v0.16b ) |
| CPU_LE( rev64 v1.16b, v1.16b ) |
| CPU_LE( rev64 v2.16b, v2.16b ) |
| CPU_LE( rev64 v3.16b, v3.16b ) |
| CPU_LE( rev64 v4.16b, v4.16b ) |
| CPU_LE( rev64 v5.16b, v5.16b ) |
| CPU_LE( rev64 v6.16b, v6.16b ) |
| CPU_LE( rev64 v7.16b, v7.16b ) |
| CPU_LE( ext v0.16b, v0.16b, v0.16b, #8 ) |
| CPU_LE( ext v1.16b, v1.16b, v1.16b, #8 ) |
| CPU_LE( ext v2.16b, v2.16b, v2.16b, #8 ) |
| CPU_LE( ext v3.16b, v3.16b, v3.16b, #8 ) |
| CPU_LE( ext v4.16b, v4.16b, v4.16b, #8 ) |
| CPU_LE( ext v5.16b, v5.16b, v5.16b, #8 ) |
| CPU_LE( ext v6.16b, v6.16b, v6.16b, #8 ) |
| CPU_LE( ext v7.16b, v7.16b, v7.16b, #8 ) |
| |
| // XOR the first 16 data *bits* with the initial CRC value. |
| movi v8.16b, #0 |
| mov v8.h[7], init_crc |
| eor v0.16b, v0.16b, v8.16b |
| |
| // Load the constants for folding across 128 bytes. |
| ld1 {fold_consts.2d}, [fold_consts_ptr] |
| __pmull_pre_\p fold_consts |
| |
| // Subtract 128 for the 128 data bytes just consumed. Subtract another |
| // 128 to simplify the termination condition of the following loop. |
| sub len, len, #256 |
| |
| // While >= 128 data bytes remain (not counting v0-v7), fold the 128 |
| // bytes v0-v7 into them, storing the result back into v0-v7. |
| .Lfold_128_bytes_loop_\@: |
| fold_32_bytes \p, v0, v1 |
| fold_32_bytes \p, v2, v3 |
| fold_32_bytes \p, v4, v5 |
| fold_32_bytes \p, v6, v7 |
| |
| subs len, len, #128 |
| b.lt .Lfold_128_bytes_loop_done_\@ |
| |
| if_will_cond_yield_neon |
| stp q0, q1, [sp, #.Lframe_local_offset] |
| stp q2, q3, [sp, #.Lframe_local_offset + 32] |
| stp q4, q5, [sp, #.Lframe_local_offset + 64] |
| stp q6, q7, [sp, #.Lframe_local_offset + 96] |
| do_cond_yield_neon |
| ldp q0, q1, [sp, #.Lframe_local_offset] |
| ldp q2, q3, [sp, #.Lframe_local_offset + 32] |
| ldp q4, q5, [sp, #.Lframe_local_offset + 64] |
| ldp q6, q7, [sp, #.Lframe_local_offset + 96] |
| ld1 {fold_consts.2d}, [fold_consts_ptr] |
| __pmull_init_\p |
| __pmull_pre_\p fold_consts |
| endif_yield_neon |
| |
| b .Lfold_128_bytes_loop_\@ |
| |
| .Lfold_128_bytes_loop_done_\@: |
| |
| // Now fold the 112 bytes in v0-v6 into the 16 bytes in v7. |
| |
| // Fold across 64 bytes. |
| add fold_consts_ptr, fold_consts_ptr, #16 |
| ld1 {fold_consts.2d}, [fold_consts_ptr], #16 |
| __pmull_pre_\p fold_consts |
| fold_16_bytes \p, v0, v4 |
| fold_16_bytes \p, v1, v5 |
| fold_16_bytes \p, v2, v6 |
| fold_16_bytes \p, v3, v7, 1 |
| // Fold across 32 bytes. |
| fold_16_bytes \p, v4, v6 |
| fold_16_bytes \p, v5, v7, 1 |
| // Fold across 16 bytes. |
| fold_16_bytes \p, v6, v7 |
| |
| // Add 128 to get the correct number of data bytes remaining in 0...127 |
| // (not counting v7), following the previous extra subtraction by 128. |
| // Then subtract 16 to simplify the termination condition of the |
| // following loop. |
| adds len, len, #(128-16) |
| |
| // While >= 16 data bytes remain (not counting v7), fold the 16 bytes v7 |
| // into them, storing the result back into v7. |
| b.lt .Lfold_16_bytes_loop_done_\@ |
| .Lfold_16_bytes_loop_\@: |
| __pmull_\p v8, v7, fold_consts |
| __pmull_\p v7, v7, fold_consts, 2 |
| eor v7.16b, v7.16b, v8.16b |
| ldr q0, [buf], #16 |
| CPU_LE( rev64 v0.16b, v0.16b ) |
| CPU_LE( ext v0.16b, v0.16b, v0.16b, #8 ) |
| eor v7.16b, v7.16b, v0.16b |
| subs len, len, #16 |
| b.ge .Lfold_16_bytes_loop_\@ |
| |
| .Lfold_16_bytes_loop_done_\@: |
| // Add 16 to get the correct number of data bytes remaining in 0...15 |
| // (not counting v7), following the previous extra subtraction by 16. |
| adds len, len, #16 |
| b.eq .Lreduce_final_16_bytes_\@ |
| |
| .Lhandle_partial_segment_\@: |
| // Reduce the last '16 + len' bytes where 1 <= len <= 15 and the first |
| // 16 bytes are in v7 and the rest are the remaining data in 'buf'. To |
| // do this without needing a fold constant for each possible 'len', |
| // redivide the bytes into a first chunk of 'len' bytes and a second |
| // chunk of 16 bytes, then fold the first chunk into the second. |
| |
| // v0 = last 16 original data bytes |
| add buf, buf, len |
| ldr q0, [buf, #-16] |
| CPU_LE( rev64 v0.16b, v0.16b ) |
| CPU_LE( ext v0.16b, v0.16b, v0.16b, #8 ) |
| |
| // v1 = high order part of second chunk: v7 left-shifted by 'len' bytes. |
| adr_l x4, .Lbyteshift_table + 16 |
| sub x4, x4, len |
| ld1 {v2.16b}, [x4] |
| tbl v1.16b, {v7.16b}, v2.16b |
| |
| // v3 = first chunk: v7 right-shifted by '16-len' bytes. |
| movi v3.16b, #0x80 |
| eor v2.16b, v2.16b, v3.16b |
| tbl v3.16b, {v7.16b}, v2.16b |
| |
| // Convert to 8-bit masks: 'len' 0x00 bytes, then '16-len' 0xff bytes. |
| sshr v2.16b, v2.16b, #7 |
| |
| // v2 = second chunk: 'len' bytes from v0 (low-order bytes), |
| // then '16-len' bytes from v1 (high-order bytes). |
| bsl v2.16b, v1.16b, v0.16b |
| |
| // Fold the first chunk into the second chunk, storing the result in v7. |
| __pmull_\p v0, v3, fold_consts |
| __pmull_\p v7, v3, fold_consts, 2 |
| eor v7.16b, v7.16b, v0.16b |
| eor v7.16b, v7.16b, v2.16b |
| |
| .Lreduce_final_16_bytes_\@: |
| // Reduce the 128-bit value M(x), stored in v7, to the final 16-bit CRC. |
| |
| movi v2.16b, #0 // init zero register |
| |
| // Load 'x^48 * (x^48 mod G(x))' and 'x^48 * (x^80 mod G(x))'. |
| ld1 {fold_consts.2d}, [fold_consts_ptr], #16 |
| __pmull_pre_\p fold_consts |
| |
| // Fold the high 64 bits into the low 64 bits, while also multiplying by |
| // x^64. This produces a 128-bit value congruent to x^64 * M(x) and |
| // whose low 48 bits are 0. |
| ext v0.16b, v2.16b, v7.16b, #8 |
| __pmull_\p v7, v7, fold_consts, 2 // high bits * x^48 * (x^80 mod G(x)) |
| eor v0.16b, v0.16b, v7.16b // + low bits * x^64 |
| |
| // Fold the high 32 bits into the low 96 bits. This produces a 96-bit |
| // value congruent to x^64 * M(x) and whose low 48 bits are 0. |
| ext v1.16b, v0.16b, v2.16b, #12 // extract high 32 bits |
| mov v0.s[3], v2.s[0] // zero high 32 bits |
| __pmull_\p v1, v1, fold_consts // high 32 bits * x^48 * (x^48 mod G(x)) |
| eor v0.16b, v0.16b, v1.16b // + low bits |
| |
| // Load G(x) and floor(x^48 / G(x)). |
| ld1 {fold_consts.2d}, [fold_consts_ptr] |
| __pmull_pre_\p fold_consts |
| |
| // Use Barrett reduction to compute the final CRC value. |
| __pmull_\p v1, v0, fold_consts, 2 // high 32 bits * floor(x^48 / G(x)) |
| ushr v1.2d, v1.2d, #32 // /= x^32 |
| __pmull_\p v1, v1, fold_consts // *= G(x) |
| ushr v0.2d, v0.2d, #48 |
| eor v0.16b, v0.16b, v1.16b // + low 16 nonzero bits |
| // Final CRC value (x^16 * M(x)) mod G(x) is in low 16 bits of v0. |
| |
| umov w0, v0.h[0] |
| frame_pop |
| ret |
| |
| .Lless_than_256_bytes_\@: |
| // Checksumming a buffer of length 16...255 bytes |
| |
| adr_l fold_consts_ptr, .Lfold_across_16_bytes_consts |
| |
| // Load the first 16 data bytes. |
| ldr q7, [buf], #0x10 |
| CPU_LE( rev64 v7.16b, v7.16b ) |
| CPU_LE( ext v7.16b, v7.16b, v7.16b, #8 ) |
| |
| // XOR the first 16 data *bits* with the initial CRC value. |
| movi v0.16b, #0 |
| mov v0.h[7], init_crc |
| eor v7.16b, v7.16b, v0.16b |
| |
| // Load the fold-across-16-bytes constants. |
| ld1 {fold_consts.2d}, [fold_consts_ptr], #16 |
| __pmull_pre_\p fold_consts |
| |
| cmp len, #16 |
| b.eq .Lreduce_final_16_bytes_\@ // len == 16 |
| subs len, len, #32 |
| b.ge .Lfold_16_bytes_loop_\@ // 32 <= len <= 255 |
| add len, len, #16 |
| b .Lhandle_partial_segment_\@ // 17 <= len <= 31 |
| .endm |
| |
| // |
| // u16 crc_t10dif_pmull_p8(u16 init_crc, const u8 *buf, size_t len); |
| // |
| // Assumes len >= 16. |
| // |
| ENTRY(crc_t10dif_pmull_p8) |
| crc_t10dif_pmull p8 |
| ENDPROC(crc_t10dif_pmull_p8) |
| |
| .align 5 |
| // |
| // u16 crc_t10dif_pmull_p64(u16 init_crc, const u8 *buf, size_t len); |
| // |
| // Assumes len >= 16. |
| // |
| ENTRY(crc_t10dif_pmull_p64) |
| crc_t10dif_pmull p64 |
| ENDPROC(crc_t10dif_pmull_p64) |
| |
| .section ".rodata", "a" |
| .align 4 |
| |
| // Fold constants precomputed from the polynomial 0x18bb7 |
| // G(x) = x^16 + x^15 + x^11 + x^9 + x^8 + x^7 + x^5 + x^4 + x^2 + x^1 + x^0 |
| .Lfold_across_128_bytes_consts: |
| .quad 0x0000000000006123 // x^(8*128) mod G(x) |
| .quad 0x0000000000002295 // x^(8*128+64) mod G(x) |
| // .Lfold_across_64_bytes_consts: |
| .quad 0x0000000000001069 // x^(4*128) mod G(x) |
| .quad 0x000000000000dd31 // x^(4*128+64) mod G(x) |
| // .Lfold_across_32_bytes_consts: |
| .quad 0x000000000000857d // x^(2*128) mod G(x) |
| .quad 0x0000000000007acc // x^(2*128+64) mod G(x) |
| .Lfold_across_16_bytes_consts: |
| .quad 0x000000000000a010 // x^(1*128) mod G(x) |
| .quad 0x0000000000001faa // x^(1*128+64) mod G(x) |
| // .Lfinal_fold_consts: |
| .quad 0x1368000000000000 // x^48 * (x^48 mod G(x)) |
| .quad 0x2d56000000000000 // x^48 * (x^80 mod G(x)) |
| // .Lbarrett_reduction_consts: |
| .quad 0x0000000000018bb7 // G(x) |
| .quad 0x00000001f65a57f8 // floor(x^48 / G(x)) |
| |
| // For 1 <= len <= 15, the 16-byte vector beginning at &byteshift_table[16 - |
| // len] is the index vector to shift left by 'len' bytes, and is also {0x80, |
| // ..., 0x80} XOR the index vector to shift right by '16 - len' bytes. |
| .Lbyteshift_table: |
| .byte 0x0, 0x81, 0x82, 0x83, 0x84, 0x85, 0x86, 0x87 |
| .byte 0x88, 0x89, 0x8a, 0x8b, 0x8c, 0x8d, 0x8e, 0x8f |
| .byte 0x0, 0x1, 0x2, 0x3, 0x4, 0x5, 0x6, 0x7 |
| .byte 0x8, 0x9, 0xa, 0xb, 0xc, 0xd, 0xe , 0x0 |