tests/lib/libm/t_round.c

   1 /* $NetBSD: t_round.c,v 1.4 2013/11/11 23:57:34 joerg Exp $ */
   2
   3 /*-
   4  * Copyright (c) 2011 The NetBSD Foundation, Inc.
   5  * All rights reserved.
   6  *
   7  * Redistribution and use in source and binary forms, with or without
   8  * modification, are permitted provided that the following conditions
   9  * are met:
  10  * 1. Redistributions of source code must retain the above copyright
  11  *    notice, this list of conditions and the following disclaimer.
  12  * 2. Redistributions in binary form must reproduce the above copyright
  13  *    notice, this list of conditions and the following disclaimer in the
  14  *    documentation and/or other materials provided with the distribution.
  15  *
  16  * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
  17  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
  18  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
  19  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
  20  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
  21  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
  22  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
  23  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
  24  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
  25  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
  26  * POSSIBILITY OF SUCH DAMAGE.
  27  */
  28
  29 #include <atf-c.h>
  30 #include <float.h>
  31 #include <math.h>
  32
  33 /*
  34  * This tests for a bug in the initial implementation where
  35  * precision was lost in an internal substraction, leading to
  36  * rounding into the wrong direction.
  37  */
  38
  39 /* 0.5 - EPSILON */
  40 #define VAL     0x0.7ffffffffffffcp0
  41 #define VALF    0x0.7fffff8p0
  42 #define VALL    (0.5 - LDBL_EPSILON)
  43
  44 #ifdef __vax__
  45 #define SMALL_NUM       1.0e-38
  46 #else
  47 #define SMALL_NUM       1.0e-40
  48 #endif
  49
  50 ATF_TC(round_dir);
  51 ATF_TC_HEAD(round_dir, tc)
  52 {
  53         atf_tc_set_md_var(tc, "descr","Check for rounding in wrong direction");
  54 }
  55
  56 ATF_TC_BODY(round_dir, tc)
  57 {
  58         double a = VAL, b, c;
  59         float af = VALF, bf, cf;
  60         long double al = VALL, bl, cl;
  61
  62         b = round(a);
  63         bf = roundf(af);
  64         bl = roundl(al);
  65
  66         ATF_CHECK(fabs(b) < SMALL_NUM);
  67         ATF_CHECK(fabsf(bf) < SMALL_NUM);
  68         ATF_CHECK(fabsl(bl) < SMALL_NUM);
  69
  70         c = round(-a);
  71         cf = roundf(-af);
  72         cl = roundl(-al);
  73
  74         ATF_CHECK(fabs(c) < SMALL_NUM);
  75         ATF_CHECK(fabsf(cf) < SMALL_NUM);
  76         ATF_CHECK(fabsl(cl) < SMALL_NUM);
  77 }
  78
  79 ATF_TP_ADD_TCS(tp)
  80 {
  81
  82         ATF_TP_ADD_TC(tp, round_dir);
  83
  84         return atf_no_error();
  85 }