1 /* Copyright (C) 1996-2021 Free Software Foundation, Inc. 2 This file is part of the GNU C Library. 3 4 The GNU C Library is free software; you can redistribute it and/or 5 modify it under the terms of the GNU Lesser General Public 6 License as published by the Free Software Foundation; either 7 version 2.1 of the License, or (at your option) any later version. 8 9 The GNU C Library is distributed in the hope that it will be useful, 10 but WITHOUT ANY WARRANTY; without even the implied warranty of 11 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU 12 Lesser General Public License for more details. 13 14 You should have received a copy of the GNU Lesser General Public 15 License along with the GNU C Library. If not, see 16 <https://www.gnu.org/licenses/>. */ 17 18 #include <math.h> 19 #include "mathimpl.h" 20 21 #ifndef SUFF 22 #define SUFF 23 #endif 24 #ifndef float_type 25 #define float_type double 26 #endif 27 28 #define CONCATX(a,b) __CONCAT(a,b) 29 #define s(name) CONCATX(name,SUFF) 30 #define m81(func) __m81_u(s(func)) 31 32 int s(__ieee754_ilogb)33s(__ieee754_ilogb) (float_type x) 34 { 35 float_type result; 36 unsigned long x_cond; 37 38 x_cond = __m81_test (x); 39 /* We must return consistent values for zero and NaN. */ 40 if (x_cond & __M81_COND_ZERO) 41 return FP_ILOGB0; 42 if (x_cond & (__M81_COND_NAN | __M81_COND_INF)) 43 return FP_ILOGBNAN; 44 45 __asm ("fgetexp%.x %1, %0" : "=f" (result) : "f" (x)); 46 return (int) result; 47 } 48