58 lines
3.0 KiB
C
58 lines
3.0 KiB
C
/*-*- 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/alg/alg.h"
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#include "libc/dce.h"
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#include "libc/nexgen32e/x86feature.h"
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#include "libc/str/internal.h"
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#include "libc/str/str.h"
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/**
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* Searches for substring.
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*
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* @param haystack is the search area, as a NUL-terminated string
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* @param needle is the desired substring, also NUL-terminated
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* @return pointer to first substring within haystack, or NULL
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* @asyncsignalsafe
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* @see memmem()
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*/
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char *(strstr)(const char *haystack, const char *needle) {
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if (needle[0]) {
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if (needle[1]) {
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if (!((intptr_t)needle & 0xf) && X86_HAVE(SSE4_2) && !IsTiny()) {
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return strstr$sse42(haystack, needle);
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} else {
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size_t needlelen;
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alignas(16) char needle2[64];
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needlelen = strlen(needle);
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if (needlelen < 64 && X86_HAVE(SSE4_2) && !IsTiny()) {
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memcpy(needle2, needle, (needlelen + 1) * sizeof(char));
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return strstr$sse42(haystack, needle2);
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} else {
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return tinystrstr(haystack, needle);
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}
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}
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} else {
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return strchr(haystack, needle[0]);
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}
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} else {
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return haystack;
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}
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}
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