vasilito
ff4ff35918
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.
134 lines
4.3 KiB
C
134 lines
4.3 KiB
C
/* mpfr_sub -- subtract two floating-point numbers
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Copyright 2001-2004, 2006-2025 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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#include "mpfr-impl.h"
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MPFR_HOT_FUNCTION_ATTR int
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mpfr_sub (mpfr_ptr a, mpfr_srcptr b, mpfr_srcptr c, mpfr_rnd_t rnd_mode)
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{
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MPFR_LOG_FUNC
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(("b[%Pd]=%.*Rg c[%Pd]=%.*Rg rnd=%d",
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mpfr_get_prec (b), mpfr_log_prec, b,
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mpfr_get_prec (c), mpfr_log_prec, c, rnd_mode),
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("a[%Pd]=%.*Rg", mpfr_get_prec (a), mpfr_log_prec, a));
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if (MPFR_ARE_SINGULAR_OR_UBF (b,c))
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{
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if (MPFR_IS_NAN (b) || MPFR_IS_NAN (c))
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{
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MPFR_SET_NAN (a);
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MPFR_RET_NAN;
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}
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else if (MPFR_IS_INF (b))
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{
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if (!MPFR_IS_INF (c) || MPFR_SIGN (b) != MPFR_SIGN(c))
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{
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MPFR_SET_INF (a);
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MPFR_SET_SAME_SIGN (a, b);
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MPFR_RET (0); /* exact */
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}
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else
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{
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MPFR_SET_NAN (a); /* Inf - Inf */
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MPFR_RET_NAN;
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}
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}
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else if (MPFR_IS_INF (c))
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{
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MPFR_SET_INF (a);
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MPFR_SET_OPPOSITE_SIGN (a, c);
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MPFR_RET (0); /* exact */
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}
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else if (MPFR_IS_ZERO (b))
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{
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if (MPFR_IS_ZERO (c))
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{
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int sign = rnd_mode != MPFR_RNDD
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? ((MPFR_IS_NEG(b) && MPFR_IS_POS(c)) ? -1 : 1)
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: ((MPFR_IS_POS(b) && MPFR_IS_NEG(c)) ? 1 : -1);
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MPFR_SET_SIGN (a, sign);
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MPFR_SET_ZERO (a);
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MPFR_RET(0); /* 0 - 0 is exact */
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}
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else
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return mpfr_neg (a, c, rnd_mode);
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}
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else if (MPFR_IS_ZERO (c))
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{
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return mpfr_set (a, b, rnd_mode);
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}
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else
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{
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MPFR_ASSERTD (MPFR_IS_PURE_UBF (b));
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MPFR_ASSERTD (MPFR_IS_PURE_UBF (c));
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/* mpfr_sub1sp and mpfr_add1sp are not intended to support UBF,
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for which optimization is less important. */
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if (MPFR_SIGN(b) == MPFR_SIGN(c))
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return mpfr_sub1 (a, b, c, rnd_mode);
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else if (MPFR_UBF_EXP_LESS_P (b, c))
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{
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int inexact;
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rnd_mode = MPFR_INVERT_RND (rnd_mode);
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inexact = mpfr_add1 (a, c, b, rnd_mode);
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MPFR_CHANGE_SIGN (a);
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return -inexact;
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}
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else
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return mpfr_add1 (a, b, c, rnd_mode);
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}
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}
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MPFR_ASSERTD (MPFR_IS_PURE_FP (b));
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MPFR_ASSERTD (MPFR_IS_PURE_FP (c));
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if (MPFR_LIKELY (MPFR_SIGN (b) == MPFR_SIGN (c)))
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{ /* signs are equal, it's a real subtraction */
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if (MPFR_LIKELY (MPFR_PREC (a) == MPFR_PREC (b)
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&& MPFR_PREC (b) == MPFR_PREC (c)))
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return mpfr_sub1sp (a, b, c, rnd_mode);
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else
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return mpfr_sub1 (a, b, c, rnd_mode);
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}
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else
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{ /* signs differ, it's an addition */
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if (MPFR_GET_EXP (b) < MPFR_GET_EXP (c))
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{ /* exchange rounding modes toward +/- infinity */
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int inexact;
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rnd_mode = MPFR_INVERT_RND (rnd_mode);
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if (MPFR_LIKELY (MPFR_PREC (a) == MPFR_PREC (b)
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&& MPFR_PREC (b) == MPFR_PREC (c)))
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inexact = mpfr_add1sp (a, c, b, rnd_mode);
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else
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inexact = mpfr_add1 (a, c, b, rnd_mode);
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MPFR_CHANGE_SIGN (a);
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return -inexact;
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}
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else
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{
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if (MPFR_LIKELY (MPFR_PREC (a) == MPFR_PREC (b)
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&& MPFR_PREC (b) == MPFR_PREC (c)))
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return mpfr_add1sp (a, b, c, rnd_mode);
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else
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return mpfr_add1 (a, b, c, rnd_mode);
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}
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}
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}
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