From 102b0d2daa97dae68d3eed54d8fe37a9cc38a892 Mon Sep 17 00:00:00 2001 From: Daniel Baumann Date: Sun, 28 Apr 2024 11:13:47 +0200 Subject: Adding upstream version 2.8.0+dfsg. Signed-off-by: Daniel Baumann --- lib/libc/aarch64/memset.S | 64 +++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 64 insertions(+) create mode 100644 lib/libc/aarch64/memset.S (limited to 'lib/libc/aarch64/memset.S') diff --git a/lib/libc/aarch64/memset.S b/lib/libc/aarch64/memset.S new file mode 100644 index 0000000..0543704 --- /dev/null +++ b/lib/libc/aarch64/memset.S @@ -0,0 +1,64 @@ +/* + * Copyright (c) 2020, Arm Limited. All rights reserved. + * + * SPDX-License-Identifier: BSD-3-Clause + */ + +#include + + .global memset + +/* ----------------------------------------------------------------------- + * void *memset(void *dst, int val, size_t count) + * + * Copy the value of 'val' (converted to an unsigned char) into + * each of the first 'count' characters of the object pointed to by 'dst'. + * + * Returns the value of 'dst'. + * ----------------------------------------------------------------------- + */ +func memset + cbz x2, exit /* exit if 'count' = 0 */ + mov x3, x0 /* keep x0 */ + tst x0, #7 + b.eq aligned /* 8-bytes aligned */ + + /* Unaligned 'dst' */ +unaligned: + strb w1, [x3], #1 + subs x2, x2, #1 + b.eq exit /* exit if 0 */ + tst x3, #7 + b.ne unaligned /* continue while unaligned */ + + /* 8-bytes aligned */ +aligned:cbz x1, x1_zero + bfi w1, w1, #8, #8 /* propagate 'val' */ + bfi w1, w1, #16, #16 + bfi x1, x1, #32, #32 + +x1_zero:ands x4, x2, #~0x3f + b.eq less_64 + +write_64: + .rept 4 + stp x1, x1, [x3], #16 /* write 64 bytes in a loop */ + .endr + subs x4, x4, #64 + b.ne write_64 +less_64:tbz w2, #5, less_32 /* < 32 bytes */ + stp x1, x1, [x3], #16 /* write 32 bytes */ + stp x1, x1, [x3], #16 +less_32:tbz w2, #4, less_16 /* < 16 bytes */ + stp x1, x1, [x3], #16 /* write 16 bytes */ +less_16:tbz w2, #3, less_8 /* < 8 bytes */ + str x1, [x3], #8 /* write 8 bytes */ +less_8: tbz w2, #2, less_4 /* < 4 bytes */ + str w1, [x3], #4 /* write 4 bytes */ +less_4: tbz w2, #1, less_2 /* < 2 bytes */ + strh w1, [x3], #2 /* write 2 bytes */ +less_2: tbz w2, #0, exit + strb w1, [x3] /* write 1 byte */ +exit: ret + +endfunc memset -- cgit v1.2.3