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394d998315
At least in neovim, `│vi:` is not recognized as a modeline because it has no preceding whitespace. After fixing this, opening a file yields an error because `net` is not an option. (`noet`, however, is.)
143 lines
4.8 KiB
C
143 lines
4.8 KiB
C
/*-*- mode:c;indent-tabs-mode:t;c-basic-offset:8;tab-width:8;coding:utf-8 -*-│
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│ vi: set et ft=c ts=8 tw=8 fenc=utf-8 :vi │
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╚──────────────────────────────────────────────────────────────────────────────╝
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│ │
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│ Musl Libc │
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│ Copyright © 2005-2014 Rich Felker, et al. │
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│ │
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│ Permission is hereby granted, free of charge, to any person obtaining │
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│ a copy of this software and associated documentation files (the │
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│ "Software"), to deal in the Software without restriction, including │
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│ without limitation the rights to use, copy, modify, merge, publish, │
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│ distribute, sublicense, and/or sell copies of the Software, and to │
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│ permit persons to whom the Software is furnished to do so, subject to │
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│ the following conditions: │
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│ │
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│ The above copyright notice and this permission notice shall be │
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│ included in all copies or substantial portions of the Software. │
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│ │
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│ THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, │
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│ EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF │
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│ MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. │
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│ IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY │
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│ CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, │
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│ TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE │
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│ SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE. │
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│ │
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╚─────────────────────────────────────────────────────────────────────────────*/
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#include "libc/math.h"
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#include "libc/tinymath/ldshape.internal.h"
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#if !(LDBL_MANT_DIG == 53 && LDBL_MAX_EXP == 1024)
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asm(".ident\t\"\\n\\n\
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Musl libc (MIT License)\\n\
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Copyright 2005-2014 Rich Felker, et. al.\"");
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asm(".include \"libc/disclaimer.inc\"");
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// clang-format off
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/**
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* Does (𝑥 rem 𝑦) w/ round()-style rounding.
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* @return remainder ∈ (-|𝑦|,|𝑦|) in %xmm0
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* @define 𝑥-trunc(𝑥/𝑦)*𝑦
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*/
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long double fmodl(long double x, long double y) {
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#if (LDBL_MANT_DIG == 64 || LDBL_MANT_DIG == 113) && LDBL_MAX_EXP == 16384
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union ldshape ux = {x}, uy = {y};
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int ex = ux.i.se & 0x7fff;
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int ey = uy.i.se & 0x7fff;
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int sx = ux.i.se & 0x8000;
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if (y == 0 || isnan(y) || ex == 0x7fff)
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return (x*y)/(x*y);
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ux.i.se = ex;
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uy.i.se = ey;
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if (ux.f <= uy.f) {
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if (ux.f == uy.f)
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return 0*x;
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return x;
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}
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/* normalize x and y */
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if (!ex) {
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ux.f *= 0x1p120f;
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ex = ux.i.se - 120;
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}
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if (!ey) {
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uy.f *= 0x1p120f;
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ey = uy.i.se - 120;
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}
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/* x mod y */
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#if LDBL_MANT_DIG == 64
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uint64_t i, mx, my;
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mx = ux.i.m;
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my = uy.i.m;
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for (; ex > ey; ex--) {
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i = mx - my;
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if (mx >= my) {
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if (i == 0)
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return 0*x;
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mx = 2*i;
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} else if (2*mx < mx) {
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mx = 2*mx - my;
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} else {
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mx = 2*mx;
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}
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}
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i = mx - my;
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if (mx >= my) {
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if (i == 0)
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return 0*x;
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mx = i;
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}
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for (; mx >> 63 == 0; mx *= 2, ex--);
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ux.i.m = mx;
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#elif LDBL_MANT_DIG == 113
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uint64_t hi, lo, xhi, xlo, yhi, ylo;
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xhi = (ux.i2.hi & -1ULL>>16) | 1ULL<<48;
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yhi = (uy.i2.hi & -1ULL>>16) | 1ULL<<48;
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xlo = ux.i2.lo;
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ylo = uy.i2.lo;
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for (; ex > ey; ex--) {
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hi = xhi - yhi;
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lo = xlo - ylo;
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if (xlo < ylo)
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hi -= 1;
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if (hi >> 63 == 0) {
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if ((hi|lo) == 0)
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return 0*x;
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xhi = 2*hi + (lo>>63);
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xlo = 2*lo;
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} else {
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xhi = 2*xhi + (xlo>>63);
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xlo = 2*xlo;
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}
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}
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hi = xhi - yhi;
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lo = xlo - ylo;
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if (xlo < ylo)
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hi -= 1;
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if (hi >> 63 == 0) {
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if ((hi|lo) == 0)
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return 0*x;
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xhi = hi;
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xlo = lo;
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}
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for (; xhi >> 48 == 0; xhi = 2*xhi + (xlo>>63), xlo = 2*xlo, ex--);
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ux.i2.hi = xhi;
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ux.i2.lo = xlo;
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#endif
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/* scale result */
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if (ex <= 0) {
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ux.i.se = (ex+120)|sx;
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ux.f *= 0x1p-120f;
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} else
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ux.i.se = ex|sx;
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return ux.f;
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#else
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#error "architecture unsupported"
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#endif
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}
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#endif /* long double is long */
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