1/* mpfr_fmma, mpfr_fmms -- Compute a*b +/- c*d 2 3Copyright 2014-2023 Free Software Foundation, Inc. 4Contributed by the AriC and Caramba projects, INRIA. 5 6This file is part of the GNU MPFR Library. 7 8The GNU MPFR Library is free software; you can redistribute it and/or modify 9it under the terms of the GNU Lesser General Public License as published by 10the Free Software Foundation; either version 3 of the License, or (at your 11option) any later version. 12 13The GNU MPFR Library is distributed in the hope that it will be useful, but 14WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY 15or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public 16License for more details. 17 18You should have received a copy of the GNU Lesser General Public License 19along with the GNU MPFR Library; see the file COPYING.LESSER. If not, see 20https://www.gnu.org/licenses/ or write to the Free Software Foundation, Inc., 2151 Franklin St, Fifth Floor, Boston, MA 02110-1301, USA. */ 22 23#include "mpfr-impl.h" 24 25/* compute a*b+c*d if neg=0 (fmma), a*b-c*d otherwise (fmms) */ 26static int 27mpfr_fmma_aux (mpfr_ptr z, mpfr_srcptr a, mpfr_srcptr b, mpfr_srcptr c, 28 mpfr_srcptr d, mpfr_rnd_t rnd, int neg) 29{ 30 mpfr_ubf_t u, v; 31 mpfr_t zz; 32 mpfr_prec_t prec_z = MPFR_PREC(z); 33 mp_size_t un, vn; 34 mpfr_limb_ptr up, vp, zp; 35 int inex; 36 MPFR_TMP_DECL(marker); 37 38 MPFR_LOG_FUNC 39 (("a[%Pu]=%.*Rg b[%Pu]=%.*Rg c[%Pu]=%.*Rg d[%Pu]=%.*Rg rnd=%d neg=%d", 40 mpfr_get_prec (a), mpfr_log_prec, a, 41 mpfr_get_prec (b), mpfr_log_prec, b, 42 mpfr_get_prec (c), mpfr_log_prec, c, 43 mpfr_get_prec (d), mpfr_log_prec, d, rnd, neg), 44 ("z[%Pu]=%.*Rg inex=%d", 45 mpfr_get_prec (z), mpfr_log_prec, z, inex)); 46 47 MPFR_TMP_MARK (marker); 48 49 un = MPFR_LIMB_SIZE (a) + MPFR_LIMB_SIZE (b); 50 vn = MPFR_LIMB_SIZE (c) + MPFR_LIMB_SIZE (d); 51 MPFR_TMP_INIT (up, u, (mpfr_prec_t) un * GMP_NUMB_BITS, un); 52 MPFR_TMP_INIT (vp, v, (mpfr_prec_t) vn * GMP_NUMB_BITS, vn); 53 54 mpfr_ubf_mul_exact (u, a, b); 55 mpfr_ubf_mul_exact (v, c, d); 56 if (prec_z == MPFR_PREC(a) && prec_z == MPFR_PREC(b) && 57 prec_z == MPFR_PREC(c) && prec_z == MPFR_PREC(d) && 58 un == MPFR_PREC2LIMBS(2 * prec_z)) 59 { 60 MPFR_TMP_INIT (zp, zz, 2 * prec_z, un); 61 MPFR_PREC(u) = MPFR_PREC(v) = 2 * prec_z; 62 inex = (neg == 0) ? mpfr_add (zz, (mpfr_srcptr) u, (mpfr_srcptr) v, rnd) 63 : mpfr_sub (zz, (mpfr_srcptr) u, (mpfr_srcptr) v, rnd); 64 inex = mpfr_set_1_2 (z, zz, rnd, inex); 65 } 66 else 67 inex = (neg == 0) ? mpfr_add (z, (mpfr_srcptr) u, (mpfr_srcptr) v, rnd) 68 : mpfr_sub (z, (mpfr_srcptr) u, (mpfr_srcptr) v, rnd); 69 70 MPFR_UBF_CLEAR_EXP (u); 71 MPFR_UBF_CLEAR_EXP (v); 72 73 MPFR_TMP_FREE (marker); 74 75 return inex; 76} 77 78/* z <- a*b + c*d */ 79int 80mpfr_fmma (mpfr_ptr z, mpfr_srcptr a, mpfr_srcptr b, mpfr_srcptr c, 81 mpfr_srcptr d, mpfr_rnd_t rnd) 82{ 83 return mpfr_fmma_aux (z, a, b, c, d, rnd, 0); 84} 85 86/* z <- a*b - c*d */ 87int 88mpfr_fmms (mpfr_ptr z, mpfr_srcptr a, mpfr_srcptr b, mpfr_srcptr c, 89 mpfr_srcptr d, mpfr_rnd_t rnd) 90{ 91 return mpfr_fmma_aux (z, a, b, c, d, rnd, 1); 92} 93