| /* Test of logb*() function family. |
| Copyright (C) 2012-2020 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 <https://www.gnu.org/licenses/>. */ |
| |
| static DOUBLE |
| my_ldexp (DOUBLE x, int d) |
| { |
| for (; d > 0; d--) |
| x *= L_(2.0); |
| for (; d < 0; d++) |
| x *= L_(0.5); |
| return x; |
| } |
| |
| static void |
| test_function (void) |
| { |
| int i; |
| VOLATILE DOUBLE x; |
| DOUBLE y; |
| |
| /* Some particular values. */ |
| x = L_(0.6); |
| y = LOGB (x); |
| ASSERT (y == - L_(1.0)); |
| |
| x = L_(1.2); |
| y = LOGB (x); |
| ASSERT (y == L_(0.0)); |
| |
| x = L_(2.1); |
| y = LOGB (x); |
| ASSERT (y == L_(1.0)); |
| |
| x = L_(3.9); |
| y = LOGB (x); |
| ASSERT (y == L_(1.0)); |
| |
| x = L_(4.0); |
| y = LOGB (x); |
| ASSERT (y == (FLT_RADIX == 2 ? L_(2.0) : L_(1.0))); |
| |
| x = L_(0.25); |
| y = LOGB (x); |
| ASSERT (y == (FLT_RADIX == 2 ? - L_(2.0) : - L_(1.0))); |
| |
| /* Zero. */ |
| ASSERT (LOGB (L_(0.0)) == - HUGEVAL); |
| ASSERT (LOGB (MINUS_ZERO) == - HUGEVAL); |
| |
| /* From here on, this test assumes FLT_RADIX == 2. */ |
| |
| for (i = 1, x = L_(1.0); i <= MAX_EXP; i++, x *= L_(2.0)) |
| { |
| y = LOGB (x); |
| ASSERT (y == (DOUBLE)(i - 1)); |
| } |
| for (i = 1, x = L_(1.0); i >= MIN_NORMAL_EXP; i--, x *= L_(0.5)) |
| { |
| y = LOGB (x); |
| ASSERT (y == (DOUBLE)(i - 1)); |
| } |
| for (; i >= MIN_EXP - 100 && x > L_(0.0); i--, x *= L_(0.5)) |
| { |
| y = LOGB (x); |
| ASSERT (y == (DOUBLE)(i - 1)); |
| } |
| |
| for (i = 1, x = - L_(1.0); i <= MAX_EXP; i++, x *= L_(2.0)) |
| { |
| y = LOGB (x); |
| ASSERT (y == (DOUBLE)(i - 1)); |
| } |
| for (i = 1, x = - L_(1.0); i >= MIN_NORMAL_EXP; i--, x *= L_(0.5)) |
| { |
| y = LOGB (x); |
| ASSERT (y == (DOUBLE)(i - 1)); |
| } |
| for (; i >= MIN_EXP - 100 && x < L_(0.0); i--, x *= L_(0.5)) |
| { |
| y = LOGB (x); |
| ASSERT (y == (DOUBLE)(i - 1)); |
| } |
| |
| for (i = 1, x = L_(1.01); i <= MAX_EXP; i++, x *= L_(2.0)) |
| { |
| y = LOGB (x); |
| ASSERT (y == (DOUBLE)(i - 1)); |
| } |
| for (i = 1, x = L_(1.01); i >= MIN_NORMAL_EXP; i--, x *= L_(0.5)) |
| { |
| y = LOGB (x); |
| ASSERT (y == (DOUBLE)(i - 1)); |
| } |
| for (; i >= MIN_EXP - 100 && x > L_(0.0); i--, x *= L_(0.5)) |
| { |
| y = LOGB (x); |
| ASSERT (y == (DOUBLE)(i - 1)); |
| } |
| |
| for (i = 1, x = L_(1.73205); i <= MAX_EXP; i++, x *= L_(2.0)) |
| { |
| y = LOGB (x); |
| ASSERT (y == (DOUBLE)(i - 1)); |
| } |
| for (i = 1, x = L_(1.73205); i >= MIN_NORMAL_EXP; i--, x *= L_(0.5)) |
| { |
| y = LOGB (x); |
| ASSERT (y == (DOUBLE)(i - 1)); |
| } |
| for (; i >= MIN_EXP - 100 && x > L_(0.0); i--, x *= L_(0.5)) |
| { |
| y = LOGB (x); |
| ASSERT (y == (DOUBLE)(i - 1) || y == (DOUBLE)i); |
| } |
| |
| /* Randomized tests. */ |
| for (i = 0; i < SIZEOF (RANDOM); i++) |
| { |
| x = L_(20.0) * RANDOM[i] - L_(10.0); /* -10.0 <= x <= 10.0 */ |
| if (x != L_(0.0)) |
| { |
| DOUBLE abs_x = (x < L_(0.0) ? - x : x); |
| y = LOGB (x); |
| ASSERT (y == (DOUBLE) (int) y); |
| ASSERT (abs_x >= my_ldexp (L_(1.0), (int) y)); |
| ASSERT (abs_x < my_ldexp (L_(1.0), (int) y + 1)); |
| } |
| } |
| } |
| |
| volatile DOUBLE x; |
| DOUBLE y; |