cosmopolitan/libc/x/utf8to32.c
Jōshin e16a7d8f3b
flip et / noet in modelines
`et` means `expandtab`.

```sh
rg 'vi: .* :vi' -l -0 | \
  xargs -0 sed -i '' 's/vi: \(.*\) et\(.*\)  :vi/vi: \1 xoet\2:vi/'
rg 'vi: .*  :vi' -l -0 | \
  xargs -0 sed -i '' 's/vi: \(.*\)noet\(.*\):vi/vi: \1et\2  :vi/'
rg 'vi: .*  :vi' -l -0 | \
  xargs -0 sed -i '' 's/vi: \(.*\)xoet\(.*\):vi/vi: \1noet\2:vi/'
```
2023-12-07 22:17:11 -05:00

94 lines
3.9 KiB
C

/*-*- mode:c;indent-tabs-mode:nil;c-basic-offset:2;tab-width:8;coding:utf-8 -*-│
│ vi: set et 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/intrin/likely.h"
#include "libc/intrin/pcmpgtb.h"
#include "libc/intrin/pmovmskb.h"
#include "libc/intrin/punpckhbw.h"
#include "libc/intrin/punpckhwd.h"
#include "libc/intrin/punpcklbw.h"
#include "libc/intrin/punpcklwd.h"
#include "libc/mem/mem.h"
#include "libc/str/str.h"
#include "libc/str/thompike.h"
#include "libc/str/utf16.h"
#include "libc/x/x.h"
/**
* Transcodes UTF-8 to UTF-32.
*
* @param p is input value
* @param n if -1 implies strlen
* @param z if non-NULL receives output length
*/
wchar_t *utf8to32(const char *p, size_t n, size_t *z) {
size_t i;
unsigned m, j;
wint_t x, a, b;
wchar_t *r, *q;
uint8_t v1[16], v2[16], v3[16], v4[16], vz[16];
if (z) *z = 0;
if (n == -1) n = p ? strlen(p) : 0;
if ((q = r = malloc(n * sizeof(wchar_t) + sizeof(wchar_t)))) {
for (i = 0; i < n;) {
if (!((uintptr_t)(p + i) & 15) && i + 16 < n) {
/* 10x speedup for ascii */
bzero(vz, 16);
do {
memcpy(v1, p + i, 16);
pcmpgtb((int8_t *)v2, (int8_t *)v1, (int8_t *)vz);
if (pmovmskb(v2) != 0xFFFF) break;
punpcklbw(v3, v1, vz);
punpckhbw(v1, v1, vz);
punpcklwd((void *)v4, (void *)v3, (void *)vz);
punpckhwd((void *)v3, (void *)v3, (void *)vz);
punpcklwd((void *)v2, (void *)v1, (void *)vz);
punpckhwd((void *)v1, (void *)v1, (void *)vz);
memcpy(q + 0, v4, 16);
memcpy(q + 4, v3, 16);
memcpy(q + 8, v2, 16);
memcpy(q + 12, v1, 16);
i += 16;
q += 16;
} while (i + 16 < n);
}
x = p[i++] & 0xff;
if (x >= 0300) {
a = ThomPikeByte(x);
m = ThomPikeLen(x) - 1;
if (i + m <= n) {
for (j = 0;;) {
b = p[i + j] & 0xff;
if (!ThomPikeCont(b)) break;
a = ThomPikeMerge(a, b);
if (++j == m) {
x = a;
i += j;
break;
}
}
}
}
*q++ = x;
}
if (z) *z = q - r;
*q++ = '\0';
if ((q = realloc(r, (q - r) * sizeof(wchar_t)))) r = q;
}
return r;
}