/*-*- 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                              │
│                                                                              │
│ This program is free software; you can redistribute it and/or modify         │
│ it under the terms of the GNU General Public License as published by         │
│ the Free Software Foundation; version 2 of the License.                      │
│                                                                              │
│ This program 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             │
│ General Public License for more details.                                     │
│                                                                              │
│ You should have received a copy of the GNU General Public License            │
│ along with this program; if not, write to the Free Software                  │
│ Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA                │
│ 02110-1301 USA                                                               │
╚─────────────────────────────────────────────────────────────────────────────*/
#include "libc/intrin/psignd.h"
#include "libc/str/str.h"

/**
 * Conditionally negates or zeroes ints.
 * @note goes fast w/ ssse3 (intel c. 2004, amd c. 2011)
 */
void(psignd)(int32_t a[4], const int32_t b[4], const int32_t c[4]) {
  unsigned i;
  for (i = 0; i < 4; ++i) {
    if (!c[i]) {
      a[i] = 0;
    } else if (c[i] < 0) {
      a[i] = -b[i];
    } else {
      a[i] = b[i];
    }
  }
}