Mercurial > gnulib
view tests/test-frexp.h @ 40212:8da9577294da
unistr/*, uniconv/*: Fix undefined behaviour.
Reported by Jeffrey Walton <noloader@gmail.com>.
* lib/unistr/u-cpy.h (FUNC): Don't invoke memcpy with a zero size.
* lib/unistr/u-cpy-alloc.h (FUNC): Likewise.
* lib/uniconv/u8-conv-from-enc.c (u8_conv_from_encoding): Likewise.
* lib/uniconv/u8-conv-to-enc.c (u8_conv_to_encoding): Likewise.
author | Bruno Haible <bruno@clisp.org> |
---|---|
date | Sat, 09 Mar 2019 00:01:47 +0100 |
parents | b06060465f09 |
children |
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/* Test of splitting a double into fraction and mantissa. Copyright (C) 2012-2019 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; { /* NaN. */ int exp = -9999; DOUBLE mantissa; x = NAN; mantissa = FREXP (x, &exp); ASSERT (ISNAN (mantissa)); } { /* Positive infinity. */ int exp = -9999; DOUBLE mantissa; x = INFINITY; mantissa = FREXP (x, &exp); ASSERT (mantissa == x); } { /* Negative infinity. */ int exp = -9999; DOUBLE mantissa; x = - INFINITY; mantissa = FREXP (x, &exp); ASSERT (mantissa == x); } { /* Positive zero. */ int exp = -9999; DOUBLE mantissa; x = L_(0.0); mantissa = FREXP (x, &exp); ASSERT (exp == 0); ASSERT (mantissa == x); ASSERT (!signbit (mantissa)); } { /* Negative zero. */ int exp = -9999; DOUBLE mantissa; x = MINUS_ZERO; mantissa = FREXP (x, &exp); ASSERT (exp == 0); ASSERT (mantissa == x); ASSERT (signbit (mantissa)); } for (i = 1, x = L_(1.0); i <= MAX_EXP; i++, x *= L_(2.0)) { int exp = -9999; DOUBLE mantissa = FREXP (x, &exp); ASSERT (exp == i); ASSERT (mantissa == L_(0.5)); } for (i = 1, x = L_(1.0); i >= MIN_NORMAL_EXP; i--, x *= L_(0.5)) { int exp = -9999; DOUBLE mantissa = FREXP (x, &exp); ASSERT (exp == i); ASSERT (mantissa == L_(0.5)); } for (; i >= MIN_EXP - 100 && x > L_(0.0); i--, x *= L_(0.5)) { int exp = -9999; DOUBLE mantissa = FREXP (x, &exp); ASSERT (exp == i); ASSERT (mantissa == L_(0.5)); } for (i = 1, x = - L_(1.0); i <= MAX_EXP; i++, x *= L_(2.0)) { int exp = -9999; DOUBLE mantissa = FREXP (x, &exp); ASSERT (exp == i); ASSERT (mantissa == - L_(0.5)); } for (i = 1, x = - L_(1.0); i >= MIN_NORMAL_EXP; i--, x *= L_(0.5)) { int exp = -9999; DOUBLE mantissa = FREXP (x, &exp); ASSERT (exp == i); ASSERT (mantissa == - L_(0.5)); } for (; i >= MIN_EXP - 100 && x < L_(0.0); i--, x *= L_(0.5)) { int exp = -9999; DOUBLE mantissa = FREXP (x, &exp); ASSERT (exp == i); ASSERT (mantissa == - L_(0.5)); } for (i = 1, x = L_(1.01); i <= MAX_EXP; i++, x *= L_(2.0)) { int exp = -9999; DOUBLE mantissa = FREXP (x, &exp); ASSERT (exp == i); ASSERT (mantissa == L_(0.505)); } for (i = 1, x = L_(1.01); i >= MIN_NORMAL_EXP; i--, x *= L_(0.5)) { int exp = -9999; DOUBLE mantissa = FREXP (x, &exp); ASSERT (exp == i); ASSERT (mantissa == L_(0.505)); } for (; i >= MIN_EXP - 100 && x > L_(0.0); i--, x *= L_(0.5)) { int exp = -9999; DOUBLE mantissa = FREXP (x, &exp); ASSERT (exp == i); ASSERT (mantissa >= L_(0.5)); ASSERT (mantissa < L_(1.0)); ASSERT (mantissa == my_ldexp (x, - exp)); } for (i = 1, x = L_(1.73205); i <= MAX_EXP; i++, x *= L_(2.0)) { int exp = -9999; DOUBLE mantissa = FREXP (x, &exp); ASSERT (exp == i); ASSERT (mantissa == L_(0.866025)); } for (i = 1, x = L_(1.73205); i >= MIN_NORMAL_EXP; i--, x *= L_(0.5)) { int exp = -9999; DOUBLE mantissa = FREXP (x, &exp); ASSERT (exp == i); ASSERT (mantissa == L_(0.866025)); } for (; i >= MIN_EXP - 100 && x > L_(0.0); i--, x *= L_(0.5)) { int exp = -9999; DOUBLE mantissa = FREXP (x, &exp); ASSERT (exp == i || exp == i + 1); ASSERT (mantissa >= L_(0.5)); ASSERT (mantissa < L_(1.0)); ASSERT (mantissa == my_ldexp (x, - exp)); } /* Randomized tests. */ for (i = 0; i < SIZEOF (RANDOM); i++) { x = L_(20.0) * RANDOM[i] - L_(10.0); /* -10.0 <= x <= 10.0 */ { int exp = -9999; DOUBLE mantissa = FREXP (x, &exp); ASSERT (x == my_ldexp (mantissa, exp)); } } }