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Red Bear OS is a full fork. All sources must be available from git clone with zero network access. Removed gitignore rules that excluded fetched source trees under recipes/*/source/, local/recipes/kde/*/source/, local/recipes/qt/*/source/, and vendor source trees. Build artifacts (target/, build/, source.tar, *.o, *.so) remain excluded. 127291 files added — kernel, relibc, base, bootloader, pkgar, all KDE/Qt frameworks, mesa, wayland, DRM drivers, and every other recipe source.
147 lines
3.9 KiB
C
147 lines
3.9 KiB
C
/* mpfr_set_float128 -- convert a binary128 (a.k.a. float128) number to
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a multiple precision floating-point number
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Copyright 2012-2025 Free Software Foundation, Inc.
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Contributed by the Pascaline and Caramba projects, INRIA.
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This file is part of the GNU MPFR Library.
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The GNU MPFR Library is free software; you can redistribute it and/or modify
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it under the terms of the GNU Lesser General Public License as published by
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the Free Software Foundation; either version 3 of the License, or (at your
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option) any later version.
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The GNU MPFR Library is distributed in the hope that it will be useful, but
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WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
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or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public
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License for more details.
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You should have received a copy of the GNU Lesser General Public License
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along with the GNU MPFR Library; see the file COPYING.LESSER.
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If not, see <https://www.gnu.org/licenses/>. */
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#define MPFR_NEED_LONGLONG_H
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#include "mpfr-impl.h"
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#ifdef MPFR_WANT_FLOAT128
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/* Note: mpfr_get_float128 is a macro defined as the actual binary128 type:
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either _Float128 or __float128. */
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#if MPFR_WANT_FLOAT128 == 1
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/* _Float128 type from ISO C23 */
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# define MPFR_FLOAT128_MAX 0x1.ffffffffffffffffffffffffffffp+16383f128
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#elif MPFR_WANT_FLOAT128 == 2
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/* __float128 type (GNU C extension) */
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# define MPFR_FLOAT128_MAX 0x1.ffffffffffffffffffffffffffffp+16383q
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#else
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# error "Unsupported value for MPFR_WANT_FLOAT128"
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#endif
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int
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mpfr_set_float128 (mpfr_ptr r, mpfr_float128 d, mpfr_rnd_t rnd_mode)
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{
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mpfr_t t;
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mp_limb_t *tp;
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int inexact, shift_exp, neg, e, i;
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mpfr_float128 p[14], q[14];
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MPFR_SAVE_EXPO_DECL (expo);
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/* Check for NaN */
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if (MPFR_UNLIKELY (DOUBLE_ISNAN (d)))
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{
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MPFR_SET_NAN(r);
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MPFR_RET_NAN;
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}
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/* Check for INF */
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if (MPFR_UNLIKELY (d > MPFR_FLOAT128_MAX))
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{
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MPFR_SET_INF (r);
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MPFR_SET_POS (r);
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return 0;
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}
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else if (MPFR_UNLIKELY (d < -MPFR_FLOAT128_MAX))
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{
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MPFR_SET_INF (r);
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MPFR_SET_NEG (r);
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return 0;
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}
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/* Check for ZERO */
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else if (MPFR_UNLIKELY (d == (mpfr_float128) 0.0))
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return mpfr_set_d (r, (double) d, rnd_mode);
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shift_exp = 0; /* invariant: remainder to deal with is d*2^shift_exp */
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neg = d < 0;
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if (d < 0)
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d = -d;
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/* Scaling, avoiding (slow) divisions. Should the tables be cached? */
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if (d >= 1.0)
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{
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p[0] = 2.0;
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q[0] = 0.5;
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e = 1;
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/* p[i] = 2^(2^i), q[i] = 1/p[i] */
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for (i = 0; i < 13 && d >= p[i]; i++)
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{
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p[i+1] = p[i] * p[i];
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q[i+1] = q[i] * q[i];
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e <<= 1;
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}
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for (; i >= 0; e >>= 1, i--)
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if (d >= p[i])
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{
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d *= q[i];
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shift_exp += e;
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}
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d *= 0.5;
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shift_exp++;
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}
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else if (d < 0.5)
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{
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p[0] = 2.0;
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q[0] = 0.5;
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e = 1;
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/* p[i] = 2^(2^i), q[i] = 1/p[i] */
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for (i = 0; i < 13 && d < q[i]; i++)
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{
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p[i+1] = p[i] * p[i];
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q[i+1] = q[i] * q[i];
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e <<= 1;
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}
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/* The while() may be needed for i = 13 due to subnormals.
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This can probably be improved without yielding an underflow. */
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for (; i >= 0; e >>= 1, i--)
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while (d < q[i])
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{
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d *= p[i];
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shift_exp -= e;
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}
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}
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MPFR_ASSERTD (d >= 0.5 && d < 1.0);
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mpfr_init2 (t, IEEE_FLOAT128_MANT_DIG);
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tp = MPFR_MANT (t);
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MPFR_SAVE_EXPO_MARK (expo);
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MPFR_SET_EXP (t, shift_exp);
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MPFR_SET_SIGN (t, neg ? MPFR_SIGN_NEG : MPFR_SIGN_POS);
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for (i = MPFR_LAST_LIMB (t); i >= 0; i--)
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{
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d *= 2 * (mpfr_float128) MPFR_LIMB_HIGHBIT;
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tp[i] = (mp_limb_t) d;
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d -= tp[i];
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}
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inexact = mpfr_set (r, t, rnd_mode);
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mpfr_clear (t);
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MPFR_SAVE_EXPO_FREE (expo);
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return mpfr_check_range (r, inexact, rnd_mode);
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}
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#endif /* MPFR_WANT_FLOAT128 */
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