mirror of
https://github.com/jart/cosmopolitan.git
synced 2025-01-31 11:37:35 +00:00
43 lines
2.4 KiB
C
43 lines
2.4 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 2020 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/intrin/palignr.h"
|
||
#include "libc/assert.h"
|
||
#include "libc/macros.internal.h"
|
||
|
||
/**
|
||
* Overlaps vectors.
|
||
*
|
||
* 𝑖= 0 means 𝑐←𝑎
|
||
* 0<𝑖<16 means 𝑐←𝑎║𝑏
|
||
* 𝑖=16 means 𝑐←𝑏
|
||
* 16<𝑖<32 means 𝑐←𝑏║0
|
||
* 𝑖≥32 means 𝑐←0
|
||
*
|
||
* @param 𝑖 goes faster as constexpr
|
||
* @note not compatible with mmx
|
||
* @see pvalignr()
|
||
* @mayalias
|
||
*/
|
||
void(palignr)(void *c, const void *b, const void *a, unsigned long i) {
|
||
char t[48];
|
||
__builtin_memcpy(t, a, 16);
|
||
__builtin_memcpy(t + 16, b, 16);
|
||
__builtin_memset(t + 32, 0, 16);
|
||
__builtin_memcpy(c, t + MIN(i, 32), 16);
|
||
}
|