| /* Copyright (C) 2012-2018 Free Software Foundation, Inc. |
| |
| This file is part of the GNU C Library. |
| |
| The GNU C Library is free software; you can redistribute it and/or |
| modify it under the terms of the GNU Lesser General Public |
| License as published by the Free Software Foundation; either |
| version 2.1 of the License, or (at your option) any later version. |
| |
| The GNU C Library 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 |
| Lesser General Public License for more details. |
| |
| You should have received a copy of the GNU Lesser General Public |
| License along with the GNU C Library. If not, see |
| <http://www.gnu.org/licenses/>. */ |
| |
| #include <sysdep.h> |
| #include "memset-reg.h" |
| |
| #ifndef MEMSET |
| # define MEMSET memset |
| #endif |
| |
| /* Assumptions: |
| * |
| * ARMv8-a, AArch64, unaligned accesses |
| * |
| */ |
| |
| ENTRY_ALIGN (MEMSET, 6) |
| |
| DELOUSE (0) |
| DELOUSE (2) |
| |
| dup v0.16B, valw |
| add dstend, dstin, count |
| |
| cmp count, 96 |
| b.hi L(set_long) |
| cmp count, 16 |
| b.hs L(set_medium) |
| mov val, v0.D[0] |
| |
| /* Set 0..15 bytes. */ |
| tbz count, 3, 1f |
| str val, [dstin] |
| str val, [dstend, -8] |
| ret |
| nop |
| 1: tbz count, 2, 2f |
| str valw, [dstin] |
| str valw, [dstend, -4] |
| ret |
| 2: cbz count, 3f |
| strb valw, [dstin] |
| tbz count, 1, 3f |
| strh valw, [dstend, -2] |
| 3: ret |
| |
| /* Set 17..96 bytes. */ |
| L(set_medium): |
| str q0, [dstin] |
| tbnz count, 6, L(set96) |
| str q0, [dstend, -16] |
| tbz count, 5, 1f |
| str q0, [dstin, 16] |
| str q0, [dstend, -32] |
| 1: ret |
| |
| .p2align 4 |
| /* Set 64..96 bytes. Write 64 bytes from the start and |
| 32 bytes from the end. */ |
| L(set96): |
| str q0, [dstin, 16] |
| stp q0, q0, [dstin, 32] |
| stp q0, q0, [dstend, -32] |
| ret |
| |
| .p2align 3 |
| nop |
| L(set_long): |
| and valw, valw, 255 |
| bic dst, dstin, 15 |
| str q0, [dstin] |
| cmp count, 256 |
| ccmp valw, 0, 0, cs |
| b.eq L(try_zva) |
| L(no_zva): |
| sub count, dstend, dst /* Count is 16 too large. */ |
| add dst, dst, 16 |
| sub count, count, 64 + 16 /* Adjust count and bias for loop. */ |
| 1: stp q0, q0, [dst], 64 |
| stp q0, q0, [dst, -32] |
| L(tail64): |
| subs count, count, 64 |
| b.hi 1b |
| 2: stp q0, q0, [dstend, -64] |
| stp q0, q0, [dstend, -32] |
| ret |
| |
| L(try_zva): |
| #ifdef ZVA_MACRO |
| zva_macro |
| #else |
| .p2align 3 |
| mrs tmp1, dczid_el0 |
| tbnz tmp1w, 4, L(no_zva) |
| and tmp1w, tmp1w, 15 |
| cmp tmp1w, 4 /* ZVA size is 64 bytes. */ |
| b.ne L(zva_128) |
| |
| /* Write the first and last 64 byte aligned block using stp rather |
| than using DC ZVA. This is faster on some cores. |
| */ |
| L(zva_64): |
| str q0, [dst, 16] |
| stp q0, q0, [dst, 32] |
| bic dst, dst, 63 |
| stp q0, q0, [dst, 64] |
| stp q0, q0, [dst, 96] |
| sub count, dstend, dst /* Count is now 128 too large. */ |
| sub count, count, 128+64+64 /* Adjust count and bias for loop. */ |
| add dst, dst, 128 |
| nop |
| 1: dc zva, dst |
| add dst, dst, 64 |
| subs count, count, 64 |
| b.hi 1b |
| stp q0, q0, [dst, 0] |
| stp q0, q0, [dst, 32] |
| stp q0, q0, [dstend, -64] |
| stp q0, q0, [dstend, -32] |
| ret |
| |
| .p2align 3 |
| L(zva_128): |
| cmp tmp1w, 5 /* ZVA size is 128 bytes. */ |
| b.ne L(zva_other) |
| |
| str q0, [dst, 16] |
| stp q0, q0, [dst, 32] |
| stp q0, q0, [dst, 64] |
| stp q0, q0, [dst, 96] |
| bic dst, dst, 127 |
| sub count, dstend, dst /* Count is now 128 too large. */ |
| sub count, count, 128+128 /* Adjust count and bias for loop. */ |
| add dst, dst, 128 |
| 1: dc zva, dst |
| add dst, dst, 128 |
| subs count, count, 128 |
| b.hi 1b |
| stp q0, q0, [dstend, -128] |
| stp q0, q0, [dstend, -96] |
| stp q0, q0, [dstend, -64] |
| stp q0, q0, [dstend, -32] |
| ret |
| |
| L(zva_other): |
| mov tmp2w, 4 |
| lsl zva_lenw, tmp2w, tmp1w |
| add tmp1, zva_len, 64 /* Max alignment bytes written. */ |
| cmp count, tmp1 |
| blo L(no_zva) |
| |
| sub tmp2, zva_len, 1 |
| add tmp1, dst, zva_len |
| add dst, dst, 16 |
| subs count, tmp1, dst /* Actual alignment bytes to write. */ |
| bic tmp1, tmp1, tmp2 /* Aligned dc zva start address. */ |
| beq 2f |
| 1: stp q0, q0, [dst], 64 |
| stp q0, q0, [dst, -32] |
| subs count, count, 64 |
| b.hi 1b |
| 2: mov dst, tmp1 |
| sub count, dstend, tmp1 /* Remaining bytes to write. */ |
| subs count, count, zva_len |
| b.lo 4f |
| 3: dc zva, dst |
| add dst, dst, zva_len |
| subs count, count, zva_len |
| b.hs 3b |
| 4: add count, count, zva_len |
| b L(tail64) |
| #endif |
| |
| END (MEMSET) |
| libc_hidden_builtin_def (MEMSET) |