43 lines
2.5 KiB
C
43 lines
2.5 KiB
C
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/*-*- mode:c;indent-tabs-mode:nil;c-basic-offset:2;tab-width:8;coding:utf-8 -*-│
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│vi: set net ft=c ts=2 sts=2 sw=2 fenc=utf-8 :vi│
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╞══════════════════════════════════════════════════════════════════════════════╡
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│ Copyright 2020 Justine Alexandra Roberts Tunney │
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│ │
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│ This program is free software; you can redistribute it and/or modify │
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│ it under the terms of the GNU General Public License as published by │
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│ the Free Software Foundation; version 2 of the License. │
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│ │
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│ This program is distributed in the hope that it will be useful, but │
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│ WITHOUT ANY WARRANTY; without even the implied warranty of │
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│ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU │
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│ General Public License for more details. │
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│ │
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│ You should have received a copy of the GNU General Public License │
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│ along with this program; if not, write to the Free Software │
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│ Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA │
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│ 02110-1301 USA │
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╚─────────────────────────────────────────────────────────────────────────────*/
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#include "libc/intrin/phaddw.h"
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/**
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* Adds adjacent signed 16-bit integers.
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*
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* @param 𝑎 [w/o] receives reduced 𝑏 and 𝑐 concatenated
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* @param 𝑏 [r/o] supplies four pairs of shorts
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* @param 𝑐 [r/o] supplies four pairs of shorts
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* @note goes fast w/ ssse3 (intel c. 2004, amd c. 2011)
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* @mayalias
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*/
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void(phaddw)(short a[8], const short b[8], const short c[8]) {
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short t[8];
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t[0] = b[0] + b[1];
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t[1] = b[2] + b[3];
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t[2] = b[4] + b[5];
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t[3] = b[6] + b[7];
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t[4] = c[0] + c[1];
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t[5] = c[2] + c[3];
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t[6] = c[4] + c[5];
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t[7] = c[6] + c[7];
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memcpy(a, t, sizeof(t));
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}
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