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diff --git a/sysdeps/ieee754/dbl-64/slowpow.c b/sysdeps/ieee754/dbl-64/slowpow.c
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-/*
- * IBM Accurate Mathematical Library
- * written by International Business Machines Corp.
- * Copyright (C) 2001-2016 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;
-}