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 * $FreeBSD: src/tools/regression/lib/msun/test-exponential.c,v 1.4 2010/12/06 00:02:49 das Exp $
27 */
28
29 /*
30 * Tests for corner cases in exp*().
31 */
32
33 #include <assert.h>
34 #include <fenv.h>
35 #include <float.h>
36 #include <math.h>
37 #include <stdio.h>
38
39 #ifdef __i386__
40 #include <ieeefp.h>
41 #endif
42
43 #define ALL_STD_EXCEPT (FE_DIVBYZERO | FE_INEXACT | FE_INVALID | \
44 FE_OVERFLOW | FE_UNDERFLOW)
45
46 #pragma STDC FENV_ACCESS ON
47
48 /*
49 * Test that a function returns the correct value and sets the
50 * exception flags correctly. The exceptmask specifies which
51 * exceptions we should check. We need to be lenient for several
52 * reasoons, but mainly because on some architectures it's impossible
53 * to raise FE_OVERFLOW without raising FE_INEXACT.
54 *
55 * These are macros instead of functions so that assert provides more
56 * meaningful error messages.
57 *
58 * XXX The volatile here is to avoid gcc's bogus constant folding and work
59 * around the lack of support for the FENV_ACCESS pragma.
60 */
61 #define test(func, x, result, exceptmask, excepts) do { \
62 volatile long double _d = x; \
63 assert(feclearexcept(FE_ALL_EXCEPT) == 0); \
64 assert(fpequal((func)(_d), (result))); \
65 assert(((func), fetestexcept(exceptmask) == (excepts))); \
66 } while (0)
67
68 /* Test all the functions that compute b^x. */
69 #define testall0(x, result, exceptmask, excepts) do { \
70 test(exp, x, result, exceptmask, excepts); \
71 test(expf, x, result, exceptmask, excepts); \
72 test(exp2, x, result, exceptmask, excepts); \
73 test(exp2f, x, result, exceptmask, excepts); \
74 test(exp2l, x, result, exceptmask, excepts); \
75 } while (0)
76
77 /* Test all the functions that compute b^x - 1. */
78 #define testall1(x, result, exceptmask, excepts) do { \
79 test(expm1, x, result, exceptmask, excepts); \
80 test(expm1f, x, result, exceptmask, excepts); \
81 } while (0)
82
83 /*
84 * Determine whether x and y are equal, with two special rules:
85 * +0.0 != -0.0
86 * NaN == NaN
87 */
88 int
fpequal(long double x,long double y)89 fpequal(long double x, long double y)
90 {
91 return ((x == y && !signbit(x) == !signbit(y)) || isnan(x) && isnan(y));
92 }
93
94 void
run_generic_tests(void)95 run_generic_tests(void)
96 {
97
98 /* exp(0) == 1, no exceptions raised */
99 testall0(0.0, 1.0, ALL_STD_EXCEPT, 0);
100 testall1(0.0, 0.0, ALL_STD_EXCEPT, 0);
101 testall0(-0.0, 1.0, ALL_STD_EXCEPT, 0);
102 testall1(-0.0, -0.0, ALL_STD_EXCEPT, 0);
103
104 /* exp(NaN) == NaN, no exceptions raised */
105 testall0(NAN, NAN, ALL_STD_EXCEPT, 0);
106 testall1(NAN, NAN, ALL_STD_EXCEPT, 0);
107
108 /* exp(Inf) == Inf, no exceptions raised */
109 testall0(INFINITY, INFINITY, ALL_STD_EXCEPT, 0);
110 testall1(INFINITY, INFINITY, ALL_STD_EXCEPT, 0);
111
112 /* exp(-Inf) == 0, no exceptions raised */
113 testall0(-INFINITY, 0.0, ALL_STD_EXCEPT, 0);
114 testall1(-INFINITY, -1.0, ALL_STD_EXCEPT, 0);
115
116 /* exp(big) == Inf, overflow exception */
117 testall0(50000.0, INFINITY, ALL_STD_EXCEPT & ~FE_INEXACT, FE_OVERFLOW);
118 testall1(50000.0, INFINITY, ALL_STD_EXCEPT & ~FE_INEXACT, FE_OVERFLOW);
119
120 /* exp(small) == 0, underflow and inexact exceptions */
121 testall0(-50000.0, 0.0, ALL_STD_EXCEPT, FE_UNDERFLOW | FE_INEXACT);
122 testall1(-50000.0, -1.0, ALL_STD_EXCEPT, FE_INEXACT);
123 }
124
125 void
run_exp2_tests(void)126 run_exp2_tests(void)
127 {
128 int i;
129
130 /*
131 * We should insist that exp2() return exactly the correct
132 * result and not raise an inexact exception for integer
133 * arguments.
134 */
135 feclearexcept(FE_ALL_EXCEPT);
136 for (i = FLT_MIN_EXP - FLT_MANT_DIG; i < FLT_MAX_EXP; i++) {
137 assert(exp2f(i) == ldexpf(1.0, i));
138 assert(fetestexcept(ALL_STD_EXCEPT) == 0);
139 }
140 for (i = DBL_MIN_EXP - DBL_MANT_DIG; i < DBL_MAX_EXP; i++) {
141 assert(exp2(i) == ldexp(1.0, i));
142 assert(fetestexcept(ALL_STD_EXCEPT) == 0);
143 }
144 for (i = LDBL_MIN_EXP - LDBL_MANT_DIG; i < LDBL_MAX_EXP; i++) {
145 assert(exp2l(i) == ldexpl(1.0, i));
146 assert(fetestexcept(ALL_STD_EXCEPT) == 0);
147 }
148 }
149
150 int
main(int argc,char * argv[])151 main(int argc, char *argv[])
152 {
153
154 printf("1..3\n");
155
156 run_generic_tests();
157 printf("ok 1 - exponential\n");
158
159 #ifdef __i386__
160 fpsetprec(FP_PE);
161 run_generic_tests();
162 #endif
163 printf("ok 2 - exponential\n");
164
165 run_exp2_tests();
166 printf("ok 3 - exponential\n");
167
168 return (0);
169 }
170