tools/regression/lib/msun/test-exponential.c

   1 /*-
   2  * Copyright (c) 2008 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 corner cases in exp*().
  29  */
  30
  31 #include <sys/cdefs.h>
  32 __FBSDID("$FreeBSD$");
  33
  34 #include <assert.h>
  35 #include <fenv.h>
  36 #include <float.h>
  37 #include <math.h>
  38 #include <stdio.h>
  39
  40 #ifdef __i386__
  41 #include <ieeefp.h>
  42 #endif
  43
  44 #define ALL_STD_EXCEPT  (FE_DIVBYZERO | FE_INEXACT | FE_INVALID | \
  45                          FE_OVERFLOW | FE_UNDERFLOW)
  46
  47 #pragma STDC FENV_ACCESS ON
  48
  49 /*
  50  * Test that a function returns the correct value and sets the
  51  * exception flags correctly. The exceptmask specifies which
  52  * exceptions we should check. We need to be lenient for several
  53  * reasoons, but mainly because on some architectures it's impossible
  54  * to raise FE_OVERFLOW without raising FE_INEXACT.
  55  *
  56  * These are macros instead of functions so that assert provides more
  57  * meaningful error messages.
  58  *
  59  * XXX The volatile here is to avoid gcc's bogus constant folding and work
  60  *     around the lack of support for the FENV_ACCESS pragma.
  61  */
  62 #define test(func, x, result, exceptmask, excepts)      do {            \
  63         volatile long double _d = x;                                    \
  64         assert(feclearexcept(FE_ALL_EXCEPT) == 0);                      \
  65         assert(fpequal((func)(_d), (result)));                           \
  66         assert(((func), fetestexcept(exceptmask) == (excepts)));        \
  67 } while (0)
  68
  69 /* Test all the functions that compute b^x. */
  70 #define testall0(x, result, exceptmask, excepts)        do {            \
  71         test(exp, x, result, exceptmask, excepts);                      \
  72         test(expf, x, result, exceptmask, excepts);                     \
  73         test(exp2, x, result, exceptmask, excepts);                     \
  74         test(exp2f, x, result, exceptmask, excepts);                    \
  75         test(exp2l, x, result, exceptmask, excepts);                    \
  76 } while (0)
  77
  78 /* Test all the functions that compute b^x - 1. */
  79 #define testall1(x, result, exceptmask, excepts)        do {            \
  80         test(expm1, x, result, exceptmask, excepts);                    \
  81         test(expm1f, x, result, exceptmask, excepts);                   \
  82 } while (0)
  83
  84 /*
  85  * Determine whether x and y are equal, with two special rules:
  86  *      +0.0 != -0.0
  87  *       NaN == NaN
  88  */
  89 int
  90 fpequal(long double x, long double y)
  91 {
  92         return ((x == y && signbit(x) == signbit(y)) || isnan(x) && isnan(y));
  93 }
  94
  95 void
  96 run_generic_tests(void)
  97 {
  98
  99         /* exp(0) == 1, no exceptions raised */
 100         testall0(0.0, 1.0, ALL_STD_EXCEPT, 0);
 101         testall1(0.0, 0.0, ALL_STD_EXCEPT, 0);
 102         testall0(-0.0, 1.0, ALL_STD_EXCEPT, 0);
 103         testall1(-0.0, -0.0, ALL_STD_EXCEPT, 0);
 104
 105         /* exp(NaN) == NaN, no exceptions raised */
 106         testall0(NAN, NAN, ALL_STD_EXCEPT, 0);
 107         testall1(NAN, NAN, ALL_STD_EXCEPT, 0);
 108
 109         /* exp(Inf) == Inf, no exceptions raised */
 110         testall0(INFINITY, INFINITY, ALL_STD_EXCEPT, 0);
 111         testall1(INFINITY, INFINITY, ALL_STD_EXCEPT, 0);
 112
 113         /* exp(-Inf) == 0, no exceptions raised */
 114         testall0(-INFINITY, 0.0, ALL_STD_EXCEPT, 0);
 115         testall1(-INFINITY, -1.0, ALL_STD_EXCEPT, 0);
 116
 117         /* exp(big) == Inf, overflow exception */
 118         testall0(50000.0, INFINITY, ALL_STD_EXCEPT & ~FE_INEXACT, FE_OVERFLOW);
 119         testall1(50000.0, INFINITY, ALL_STD_EXCEPT & ~FE_INEXACT, FE_OVERFLOW);
 120
 121         /* exp(small) == 0, underflow and inexact exceptions */
 122         testall0(-50000.0, 0.0, ALL_STD_EXCEPT, FE_UNDERFLOW | FE_INEXACT);
 123         testall1(-50000.0, -1.0, ALL_STD_EXCEPT, FE_INEXACT);
 124 }
 125
 126 void
 127 run_exp2_tests(void)
 128 {
 129         int i;
 130
 131         /*
 132          * We should insist that exp2() return exactly the correct
 133          * result and not raise an inexact exception for integer
 134          * arguments.
 135          */
 136         feclearexcept(FE_ALL_EXCEPT);
 137         for (i = FLT_MIN_EXP - FLT_MANT_DIG; i < FLT_MAX_EXP; i++) {
 138                 assert(exp2f(i) == ldexpf(1.0, i));
 139                 assert(fetestexcept(ALL_STD_EXCEPT) == 0);
 140         }
 141         for (i = DBL_MIN_EXP - DBL_MANT_DIG; i < DBL_MAX_EXP; i++) {
 142                 assert(exp2(i) == ldexp(1.0, i));
 143                 assert(fetestexcept(ALL_STD_EXCEPT) == 0);
 144         }
 145         for (i = LDBL_MIN_EXP - LDBL_MANT_DIG; i < LDBL_MAX_EXP; i++) {
 146                 assert(exp2l(i) == ldexpl(1.0, i));
 147                 assert(fetestexcept(ALL_STD_EXCEPT) == 0);
 148         }
 149 }
 150
 151 int
 152 main(int argc, char *argv[])
 153 {
 154
 155         printf("1..3\n");
 156
 157         run_generic_tests();
 158         printf("ok 1 - exponential\n");
 159
 160 #ifdef __i386__
 161         fpsetprec(FP_PE);
 162         run_generic_tests();
 163 #endif
 164         printf("ok 2 - exponential\n");
 165
 166         run_exp2_tests();
 167         printf("ok 3 - exponential\n");
 168
 169         return (0);
 170 }