diff options
Diffstat (limited to 'sysdeps/ieee754/dbl-64/slowpow.c')
| -rw-r--r-- | sysdeps/ieee754/dbl-64/slowpow.c | 125 |
1 files changed, 0 insertions, 125 deletions
diff --git a/sysdeps/ieee754/dbl-64/slowpow.c b/sysdeps/ieee754/dbl-64/slowpow.c deleted file mode 100644 index d7c7fb3eb8..0000000000 --- a/sysdeps/ieee754/dbl-64/slowpow.c +++ /dev/null @@ -1,125 +0,0 @@ -/* - * IBM Accurate Mathematical Library - * written by International Business Machines Corp. - * Copyright (C) 2001-2018 Free Software Foundation, Inc. - * - * This program is free software; you can redistribute it and/or modify - * it under the terms of the GNU Lesser General Public License as published by - * the Free Software Foundation; either version 2.1 of the License, or - * (at your option) any later version. - * - * This program is distributed in the hope that it will be useful, - * but WITHOUT ANY WARRANTY; without even the implied warranty of - * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the - * GNU Lesser General Public License for more details. - * - * You should have received a copy of the GNU Lesser General Public License - * along with this program; if not, see <http://www.gnu.org/licenses/>. - */ -/*************************************************************************/ -/* MODULE_NAME:slowpow.c */ -/* */ -/* FUNCTION:slowpow */ -/* */ -/*FILES NEEDED:mpa.h */ -/* mpa.c mpexp.c mplog.c halfulp.c */ -/* */ -/* Given two IEEE double machine numbers y,x , routine computes the */ -/* correctly rounded (to nearest) value of x^y. Result calculated by */ -/* multiplication (in halfulp.c) or if result isn't accurate enough */ -/* then routine converts x and y into multi-precision doubles and */ -/* calls to mpexp routine */ -/*************************************************************************/ - -#include "mpa.h" -#include <math_private.h> - -#include <stap-probe.h> - -#ifndef SECTION -# define SECTION -#endif - -void __mpexp (mp_no *x, mp_no *y, int p); -void __mplog (mp_no *x, mp_no *y, int p); -double ulog (double); -double __halfulp (double x, double y); - -double -SECTION -__slowpow (double x, double y, double z) -{ - double res, res1; - mp_no mpx, mpy, mpz, mpw, mpp, mpr, mpr1; - static const mp_no eps = {-3, {1.0, 4.0}}; - int p; - - /* __HALFULP returns -10 or X^Y. */ - res = __halfulp (x, y); - - /* Return if the result was computed by __HALFULP. */ - if (res >= 0) - return res; - - /* Compute pow as long double. This is currently only used by powerpc, where - one may get 106 bits of accuracy. */ -#ifdef USE_LONG_DOUBLE_FOR_MP - long double ldw, ldz, ldpp; - static const long double ldeps = 0x4.0p-96; - - ldz = __ieee754_logl ((long double) x); - ldw = (long double) y *ldz; - ldpp = __ieee754_expl (ldw); - res = (double) (ldpp + ldeps); - res1 = (double) (ldpp - ldeps); - - /* Return the result if it is accurate enough. */ - if (res == res1) - return res; -#endif - - /* Or else, calculate using multiple precision. P = 10 implies accuracy of - 240 bits accuracy, since MP_NO has a radix of 2^24. */ - p = 10; - __dbl_mp (x, &mpx, p); - __dbl_mp (y, &mpy, p); - __dbl_mp (z, &mpz, p); - - /* z = x ^ y - log (z) = y * log (x) - z = exp (y * log (x)) */ - __mplog (&mpx, &mpz, p); - __mul (&mpy, &mpz, &mpw, p); - __mpexp (&mpw, &mpp, p); - - /* Add and subtract EPS to ensure that the result remains unchanged, i.e. we - have last bit accuracy. */ - __add (&mpp, &eps, &mpr, p); - __mp_dbl (&mpr, &res, p); - __sub (&mpp, &eps, &mpr1, p); - __mp_dbl (&mpr1, &res1, p); - if (res == res1) - { - /* Track how often we get to the slow pow code plus - its input/output values. */ - LIBC_PROBE (slowpow_p10, 4, &x, &y, &z, &res); - return res; - } - - /* If we don't, then we repeat using a higher precision. 768 bits of - precision ought to be enough for anybody. */ - p = 32; - __dbl_mp (x, &mpx, p); - __dbl_mp (y, &mpy, p); - __dbl_mp (z, &mpz, p); - __mplog (&mpx, &mpz, p); - __mul (&mpy, &mpz, &mpw, p); - __mpexp (&mpw, &mpp, p); - __mp_dbl (&mpp, &res, p); - - /* Track how often we get to the uber-slow pow code plus - its input/output values. */ - LIBC_PROBE (slowpow_p32, 4, &x, &y, &z, &res); - - return res; -} |