lib/msun/tests/nearbyint_test.c

   1 /*-
   2  * Copyright (c) 2010 David Schultz <das@FreeBSD.org>
   3  * All rights reserved.
   4  *
   5  * Redistribution and use in source and binary forms, with or without
   6  * modification, are permitted provided that the following conditions
   7  * are met:
   8  * 1. Redistributions of source code must retain the above copyright
   9  *    notice, this list of conditions and the following disclaimer.
  10  * 2. Redistributions in binary form must reproduce the above copyright
  11  *    notice, this list of conditions and the following disclaimer in the
  12  *    documentation and/or other materials provided with the distribution.
  13  *
  14  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
  15  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  16  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  17  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
  18  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  19  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  20  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  21  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  22  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  23  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  24  * SUCH DAMAGE.
  25  */
  26
  27 /*
  28  * Tests for nearbyint{,f,l}()
  29  *
  30  * TODO:
  31  * - adapt tests for rint(3)
  32  * - tests for harder values (more mantissa bits than float)
  33  */
  34
  35 #include <sys/cdefs.h>
  36 __FBSDID("$FreeBSD$");
  37
  38 #include <sys/param.h>
  39 #include <fenv.h>
  40 #include <math.h>
  41 #include <stdio.h>
  42
  43 #include "test-utils.h"
  44
  45 static const int rmodes[] = {
  46         FE_TONEAREST, FE_DOWNWARD, FE_UPWARD, FE_TOWARDZERO,
  47 };
  48
  49 /* Make sure we're testing the library, not some broken compiler built-ins. */
  50 static double (*libnearbyint)(double) = nearbyint;
  51 static float (*libnearbyintf)(float) = nearbyintf;
  52 static long double (*libnearbyintl)(long double) = nearbyintl;
  53 #define nearbyintf libnearbyintf
  54 #define nearbyint libnearbyint
  55 #define nearbyintl libnearbyintl
  56
  57 static const struct {
  58         float in;
  59         float out[3];   /* one answer per rounding mode except towardzero */
  60 } tests[] = {
  61 /* input        output (expected) */
  62     { 0.0,      { 0.0, 0.0, 0.0 }},
  63     { 0.5,      { 0.0, 0.0, 1.0 }},
  64     { M_PI,     { 3.0, 3.0, 4.0 }},
  65     { 65536.5,  { 65536, 65536, 65537 }},
  66     { INFINITY, { INFINITY, INFINITY, INFINITY }},
  67     { NAN,      { NAN, NAN, NAN }},
  68 };
  69
  70 /* Get the appropriate result for the current rounding mode. */
  71 static float
  72 get_output(int testindex, int rmodeindex, int negative)
  73 {
  74         double out;
  75
  76         if (negative) { /* swap downwards and upwards if input is negative */
  77                 if (rmodeindex == 1)
  78                         rmodeindex = 2;
  79                 else if (rmodeindex == 2)
  80                         rmodeindex = 1;
  81         }
  82         if (rmodeindex == 3) /* FE_TOWARDZERO uses the value for downwards */
  83                 rmodeindex = 1;
  84         out = tests[testindex].out[rmodeindex];
  85         return (negative ? -out : out);
  86 }
  87
  88 static void
  89 test_nearby(int testindex)
  90 {
  91         float in, out;
  92         unsigned i;
  93
  94         for (i = 0; i < sizeof(rmodes) / sizeof(rmodes[0]); i++) {
  95                 ATF_REQUIRE_EQ(0, fesetround(rmodes[i]));
  96                 ATF_REQUIRE_EQ(0, feclearexcept(ALL_STD_EXCEPT));
  97
  98                 in = tests[testindex].in;
  99                 out = get_output(testindex, i, 0);
 100                 CHECK_FPEQUAL(out, libnearbyintf(in));
 101                 CHECK_FPEQUAL(out, nearbyint(in));
 102                 CHECK_FPEQUAL(out, nearbyintl(in));
 103                 CHECK_FP_EXCEPTIONS(0, ALL_STD_EXCEPT);
 104
 105                 in = -tests[testindex].in;
 106                 out = get_output(testindex, i, 1);
 107                 CHECK_FPEQUAL(out, nearbyintf(in));
 108                 CHECK_FPEQUAL(out, nearbyint(in));
 109                 CHECK_FPEQUAL(out, nearbyintl(in));
 110                 CHECK_FP_EXCEPTIONS(0, ALL_STD_EXCEPT);
 111         }
 112 }
 113
 114 static void
 115 test_modf(int testindex)
 116 {
 117         float in, out;
 118         float ipartf, ipart_expected;
 119         double ipart;
 120         long double ipartl;
 121         unsigned i;
 122
 123         for (i = 0; i < sizeof(rmodes) / sizeof(rmodes[0]); i++) {
 124                 ATF_REQUIRE_EQ(0, fesetround(rmodes[i]));
 125                 ATF_REQUIRE_EQ(0, feclearexcept(ALL_STD_EXCEPT));
 126
 127                 in = tests[testindex].in;
 128                 ipart_expected = tests[testindex].out[1];
 129                 out = copysignf(
 130                     isinf(ipart_expected) ? 0.0 : in - ipart_expected, in);
 131                 ipartl = ipart = ipartf = 42.0;
 132
 133                 CHECK_FPEQUAL(out, modff(in, &ipartf));
 134                 CHECK_FPEQUAL(ipart_expected, ipartf);
 135                 CHECK_FPEQUAL(out, modf(in, &ipart));
 136                 CHECK_FPEQUAL(ipart_expected, ipart);
 137                 CHECK_FPEQUAL(out, modfl(in, &ipartl));
 138                 CHECK_FPEQUAL(ipart_expected, ipartl);
 139                 CHECK_FP_EXCEPTIONS(0, ALL_STD_EXCEPT);
 140
 141                 in = -in;
 142                 ipart_expected = -ipart_expected;
 143                 out = -out;
 144                 ipartl = ipart = ipartf = 42.0;
 145                 CHECK_FPEQUAL(out, modff(in, &ipartf));
 146                 CHECK_FPEQUAL(ipart_expected, ipartf);
 147                 CHECK_FPEQUAL(out, modf(in, &ipart));
 148                 CHECK_FPEQUAL(ipart_expected, ipart);
 149                 CHECK_FPEQUAL(out, modfl(in, &ipartl));
 150                 CHECK_FPEQUAL(ipart_expected, ipartl);
 151                 CHECK_FP_EXCEPTIONS(0, ALL_STD_EXCEPT);
 152         }
 153 }
 154
 155 ATF_TC_WITHOUT_HEAD(nearbyint);
 156 ATF_TC_BODY(nearbyint, tc)
 157 {
 158         unsigned i;
 159
 160         for (i = 0; i < nitems(tests); i++) {
 161                 test_nearby(i);
 162                 test_modf(i);
 163         }
 164 }
 165
 166 ATF_TP_ADD_TCS(tp)
 167 {
 168         ATF_TP_ADD_TC(tp, nearbyint);
 169
 170         return (atf_no_error());
 171 }