mirror of
https://github.com/jart/cosmopolitan.git
synced 2025-01-31 11:37:35 +00:00
d7733579d3
The amalgamated release is now confirmed to be working with Clang, including its integrated assembler. Fixes #41
100 lines
3.6 KiB
C
100 lines
3.6 KiB
C
/*-*- mode:c;indent-tabs-mode:nil;c-basic-offset:2;tab-width:8;coding:utf-8 -*-│
|
|
│vi: set net ft=c ts=2 sts=2 sw=2 fenc=utf-8 :vi│
|
|
╞══════════════════════════════════════════════════════════════════════════════╡
|
|
│ Copyright 2021 Justine Alexandra Roberts Tunney │
|
|
│ │
|
|
│ Permission to use, copy, modify, and/or distribute this software for │
|
|
│ any purpose with or without fee is hereby granted, provided that the │
|
|
│ above copyright notice and this permission notice appear in all copies. │
|
|
│ │
|
|
│ THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL │
|
|
│ WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED │
|
|
│ WARRANTIES OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE │
|
|
│ AUTHOR BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL │
|
|
│ DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR │
|
|
│ PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER │
|
|
│ TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR │
|
|
│ PERFORMANCE OF THIS SOFTWARE. │
|
|
╚─────────────────────────────────────────────────────────────────────────────*/
|
|
#include "libc/str/str.h"
|
|
|
|
/**
|
|
* Sets memory.
|
|
*
|
|
* @param p is memory address
|
|
* @param c is masked with 255 and used as repeated byte
|
|
* @param n is byte length
|
|
* @return p
|
|
* @asyncsignalsafe
|
|
*/
|
|
void *memset_pure(void *p, int c, size_t n) {
|
|
char *b;
|
|
uint64_t x;
|
|
b = p;
|
|
x = 0x0101010101010101 * (c & 0xff);
|
|
switch (n) {
|
|
case 0:
|
|
return p;
|
|
case 1:
|
|
__builtin_memcpy(b, &x, 1);
|
|
return p;
|
|
case 2:
|
|
__builtin_memcpy(b, &x, 2);
|
|
return p;
|
|
case 3:
|
|
__builtin_memcpy(b, &x, 2);
|
|
__builtin_memcpy(b + 1, &x, 2);
|
|
return p;
|
|
case 4:
|
|
__builtin_memcpy(b, &x, 4);
|
|
return p;
|
|
case 5 ... 7:
|
|
__builtin_memcpy(b, &x, 4);
|
|
__builtin_memcpy(b + n - 4, &x, 4);
|
|
return p;
|
|
case 8:
|
|
__builtin_memcpy(b, &x, 8);
|
|
return p;
|
|
case 9 ... 16:
|
|
__builtin_memcpy(b, &x, 8);
|
|
__builtin_memcpy(b + n - 8, &x, 8);
|
|
return p;
|
|
default:
|
|
do {
|
|
n -= 16;
|
|
__builtin_memcpy(b + n, &x, 8);
|
|
asm volatile("" ::: "memory");
|
|
__builtin_memcpy(b + n + 8, &x, 8);
|
|
} while (n >= 16);
|
|
switch (n) {
|
|
case 0:
|
|
return p;
|
|
case 1:
|
|
__builtin_memcpy(b, &x, 1);
|
|
return p;
|
|
case 2:
|
|
__builtin_memcpy(b, &x, 2);
|
|
return p;
|
|
case 3:
|
|
__builtin_memcpy(b, &x, 2);
|
|
__builtin_memcpy(b + 1, &x, 2);
|
|
return p;
|
|
case 4:
|
|
__builtin_memcpy(b, &x, 4);
|
|
return p;
|
|
case 5 ... 7:
|
|
__builtin_memcpy(b, &x, 4);
|
|
__builtin_memcpy(b + n - 4, &x, 4);
|
|
return p;
|
|
case 8:
|
|
__builtin_memcpy(b, &x, 8);
|
|
return p;
|
|
case 9 ... 15:
|
|
__builtin_memcpy(b, &x, 8);
|
|
__builtin_memcpy(b + n - 8, &x, 8);
|
|
return p;
|
|
default:
|
|
unreachable;
|
|
}
|
|
}
|
|
}
|