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Diffstat (limited to 'ports/sysdeps/aarch64/memset.S')
| -rw-r--r-- | ports/sysdeps/aarch64/memset.S | 229 |
1 files changed, 0 insertions, 229 deletions
diff --git a/ports/sysdeps/aarch64/memset.S b/ports/sysdeps/aarch64/memset.S deleted file mode 100644 index 06f04be044..0000000000 --- a/ports/sysdeps/aarch64/memset.S +++ /dev/null @@ -1,229 +0,0 @@ -/* Copyright (C) 2012-2014 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/>. */ - -/* Assumptions: - * - * ARMv8-a, AArch64 - * Unaligned accesses - * - */ - -#include <sysdep.h> - -/* By default we assume that the DC instruction can be used to zero - data blocks more efficiently. In some circumstances this might be - unsafe, for example in an asymmetric multiprocessor environment with - different DC clear lengths (neither the upper nor lower lengths are - safe to use). The feature can be disabled by defining DONT_USE_DC. - - If code may be run in a virtualized environment, then define - MAYBE_VIRT. This will cause the code to cache the system register - values rather than re-reading them each call. */ - -#define dstin x0 -#define val w1 -#define count x2 -#define tmp1 x3 -#define tmp1w w3 -#define tmp2 x4 -#define tmp2w w4 -#define zva_len_x x5 -#define zva_len w5 -#define zva_bits_x x6 - -#define A_l x7 -#define A_lw w7 -#define dst x8 -#define tmp3w w9 - -ENTRY_ALIGN (__memset, 6) - - mov dst, dstin /* Preserve return value. */ - ands A_lw, val, #255 -#ifndef DONT_USE_DC - b.eq L(zero_mem) -#endif - orr A_lw, A_lw, A_lw, lsl #8 - orr A_lw, A_lw, A_lw, lsl #16 - orr A_l, A_l, A_l, lsl #32 -L(tail_maybe_long): - cmp count, #64 - b.ge L(not_short) -L(tail_maybe_tiny): - cmp count, #15 - b.le L(tail15tiny) -L(tail63): - ands tmp1, count, #0x30 - b.eq L(tail15) - add dst, dst, tmp1 - cmp tmp1w, #0x20 - b.eq 1f - b.lt 2f - stp A_l, A_l, [dst, #-48] -1: - stp A_l, A_l, [dst, #-32] -2: - stp A_l, A_l, [dst, #-16] - -L(tail15): - and count, count, #15 - add dst, dst, count - stp A_l, A_l, [dst, #-16] /* Repeat some/all of last store. */ - RET - -L(tail15tiny): - /* Set up to 15 bytes. Does not assume earlier memory - being set. */ - tbz count, #3, 1f - str A_l, [dst], #8 -1: - tbz count, #2, 1f - str A_lw, [dst], #4 -1: - tbz count, #1, 1f - strh A_lw, [dst], #2 -1: - tbz count, #0, 1f - strb A_lw, [dst] -1: - RET - - /* Critical loop. Start at a new cache line boundary. Assuming - * 64 bytes per line, this ensures the entire loop is in one line. */ - .p2align 6 -L(not_short): - neg tmp2, dst - ands tmp2, tmp2, #15 - b.eq 2f - /* Bring DST to 128-bit (16-byte) alignment. We know that there's - * more than that to set, so we simply store 16 bytes and advance by - * the amount required to reach alignment. */ - sub count, count, tmp2 - stp A_l, A_l, [dst] - add dst, dst, tmp2 - /* There may be less than 63 bytes to go now. */ - cmp count, #63 - b.le L(tail63) -2: - sub dst, dst, #16 /* Pre-bias. */ - sub count, count, #64 -1: - stp A_l, A_l, [dst, #16] - stp A_l, A_l, [dst, #32] - stp A_l, A_l, [dst, #48] - stp A_l, A_l, [dst, #64]! - subs count, count, #64 - b.ge 1b - tst count, #0x3f - add dst, dst, #16 - b.ne L(tail63) - RET - -#ifndef DONT_USE_DC - /* For zeroing memory, check to see if we can use the ZVA feature to - * zero entire 'cache' lines. */ -L(zero_mem): - mov A_l, #0 - cmp count, #63 - b.le L(tail_maybe_tiny) - neg tmp2, dst - ands tmp2, tmp2, #15 - b.eq 1f - sub count, count, tmp2 - stp A_l, A_l, [dst] - add dst, dst, tmp2 - cmp count, #63 - b.le L(tail63) -1: - /* For zeroing small amounts of memory, it's not worth setting up - * the line-clear code. */ - cmp count, #128 - b.lt L(not_short) -#ifdef MAYBE_VIRT - /* For efficiency when virtualized, we cache the ZVA capability. */ - adrp tmp2, L(cache_clear) - ldr zva_len, [tmp2, #:lo12:L(cache_clear)] - tbnz zva_len, #31, L(not_short) - cbnz zva_len, L(zero_by_line) - mrs tmp1, dczid_el0 - tbz tmp1, #4, 1f - /* ZVA not available. Remember this for next time. */ - mov zva_len, #~0 - str zva_len, [tmp2, #:lo12:L(cache_clear)] - b L(not_short) -1: - mov tmp3w, #4 - and zva_len, tmp1w, #15 /* Safety: other bits reserved. */ - lsl zva_len, tmp3w, zva_len - str zva_len, [tmp2, #:lo12:L(cache_clear)] -#else - mrs tmp1, dczid_el0 - tbnz tmp1, #4, L(not_short) - mov tmp3w, #4 - and zva_len, tmp1w, #15 /* Safety: other bits reserved. */ - lsl zva_len, tmp3w, zva_len -#endif - -L(zero_by_line): - /* Compute how far we need to go to become suitably aligned. We're - * already at quad-word alignment. */ - cmp count, zva_len_x - b.lt L(not_short) /* Not enough to reach alignment. */ - sub zva_bits_x, zva_len_x, #1 - neg tmp2, dst - ands tmp2, tmp2, zva_bits_x - b.eq 1f /* Already aligned. */ - /* Not aligned, check that there's enough to copy after alignment. */ - sub tmp1, count, tmp2 - cmp tmp1, #64 - ccmp tmp1, zva_len_x, #8, ge /* NZCV=0b1000 */ - b.lt L(not_short) - /* We know that there's at least 64 bytes to zero and that it's safe - * to overrun by 64 bytes. */ - mov count, tmp1 -2: - stp A_l, A_l, [dst] - stp A_l, A_l, [dst, #16] - stp A_l, A_l, [dst, #32] - subs tmp2, tmp2, #64 - stp A_l, A_l, [dst, #48] - add dst, dst, #64 - b.ge 2b - /* We've overrun a bit, so adjust dst downwards. */ - add dst, dst, tmp2 -1: - sub count, count, zva_len_x -3: - dc zva, dst - add dst, dst, zva_len_x - subs count, count, zva_len_x - b.ge 3b - ands count, count, zva_bits_x - b.ne L(tail_maybe_long) - RET -#ifdef MAYBE_VIRT - .bss - .p2align 2 -L(cache_clear): - .space 4 -#endif -#endif /* DONT_USE_DC */ - -END (__memset) -weak_alias (__memset, memset) -libc_hidden_builtin_def (memset) |