1 /* Test of nextafter() function. 2 Copyright (C) 2010-2021 Free Software Foundation, Inc. 3 4 This program is free software: you can redistribute it and/or modify 5 it under the terms of the GNU General Public License as published by 6 the Free Software Foundation; either version 3 of the License, or 7 (at your option) any later version. 8 9 This program 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 12 GNU General Public License for more details. 13 14 You should have received a copy of the GNU General Public License 15 along with this program. If not, see <https://www.gnu.org/licenses/>. */ 16 17 /* Written by Bruno Haible <bruno@clisp.org>, 2010. */ 18 19 #include <config.h> 20 21 #include <math.h> 22 23 #include "signature.h" 24 SIGNATURE_CHECK (nextafter, double, (double, double)); 25 26 #include "macros.h" 27 28 volatile double x; 29 double y; 30 31 int 32 main () /* */ 33 { 34 /* A particular value. */ 35 x = 1.628947572; 36 /* Towards 0. */ 37 y = nextafter (x, 0); 38 ASSERT (y < x); 39 ASSERT (y > 1.628947571); 40 y = nextafter (y, x + x); 41 ASSERT (y == x); 42 /* Towards infinity. */ 43 y = nextafter (x, x + x); 44 ASSERT (y > x); 45 ASSERT (y < 1.628947573); 46 y = nextafter (y, 0); 47 ASSERT (y == x); 48 /* Towards itself. */ 49 y = nextafter (x, x); 50 ASSERT (y == x); 51 52 return 0; 53 }