/* Test of exp*() function family. Copyright (C) 2012-2023 Free Software Foundation, Inc. This program is free software: you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation, either version 3 of the License, or (at your option) any later version. This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details. You should have received a copy of the GNU General Public License along with this program. If not, see . */ static void test_function (void) { int i; int j; const DOUBLE TWO_MANT_DIG = /* Assume MANT_DIG <= 5 * 31. Use the identity n = floor(n/5) + floor((n+1)/5) + ... + floor((n+4)/5). */ (DOUBLE) (1U << ((MANT_DIG - 1) / 5)) * (DOUBLE) (1U << ((MANT_DIG - 1 + 1) / 5)) * (DOUBLE) (1U << ((MANT_DIG - 1 + 2) / 5)) * (DOUBLE) (1U << ((MANT_DIG - 1 + 3) / 5)) * (DOUBLE) (1U << ((MANT_DIG - 1 + 4) / 5)); /* Randomized tests. */ { /* Error bound, in ulps. */ const DOUBLE err_bound = (sizeof (DOUBLE) > sizeof (double) ? #if defined __i386__ && defined __FreeBSD__ /* On FreeBSD/x86 6.4, the 'long double' type really has only 53 bits of precision in the compiler but 64 bits of precision at runtime. See . The compiler has truncated all 'long double' literals in expl.c to 53 bits of precision. */ L_(1350.0) #else L_(4.0) #endif : L_(2.0)); for (i = 0; i < SIZEOF (RANDOM); i++) { DOUBLE x = L_(16.0) * RANDOM[i]; /* 0.0 <= x <= 16.0 */ DOUBLE y = EXP (x); DOUBLE z = EXP (- x); DOUBLE err = y * z - L_(1.0); ASSERT (y > L_(0.0)); ASSERT (z > L_(0.0)); ASSERT (err > - err_bound / TWO_MANT_DIG && err < err_bound / TWO_MANT_DIG); } } { /* Error bound, in ulps. */ const DOUBLE err_bound = (sizeof (DOUBLE) > sizeof (double) ? #if defined __i386__ && defined __FreeBSD__ L_(2400.0) #else L_(24.0) #endif : L_(24.0)); for (i = 0; i < SIZEOF (RANDOM) / 5; i++) for (j = 0; j < SIZEOF (RANDOM) / 5; j++) { DOUBLE x = L_(32.0) * RANDOM[i] - L_(16.0); /* -16.0 <= x <= 16.0 */ DOUBLE y = L_(32.0) * RANDOM[j] - L_(16.0); /* -16.0 <= y <= 16.0 */ DOUBLE z = - x - y; /* Approximately x + y + z = 0. */ DOUBLE err = EXP (x) * EXP (y) * EXP (z) - L_(1.0); ASSERT (err > - err_bound / TWO_MANT_DIG && err < err_bound / TWO_MANT_DIG); } } } volatile DOUBLE x; DOUBLE y;