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Diffstat (limited to 'stdio-common/tst-printf-round.c')
| -rw-r--r-- | stdio-common/tst-printf-round.c | 110 |
1 files changed, 110 insertions, 0 deletions
diff --git a/stdio-common/tst-printf-round.c b/stdio-common/tst-printf-round.c new file mode 100644 index 0000000000..2bd46079ac --- /dev/null +++ b/stdio-common/tst-printf-round.c @@ -0,0 +1,110 @@ +/* Test for correct rounding of printf floating-point output. + Copyright (C) 2012 Free Software Foundation, Inc. + This file is part of the GNU C Library. + + The GNU C Library is free software; you can redistribute it and/or + modify it under the terms of the GNU Lesser General Public + License as published by the Free Software Foundation; either + version 2.1 of the License, or (at your option) any later version. + + The GNU C Library 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 + Lesser General Public License for more details. + + You should have received a copy of the GNU Lesser General Public + License along with the GNU C Library; if not, see + <http://www.gnu.org/licenses/>. */ + +#include <fenv.h> +#include <stdio.h> +#include <string.h> + +struct dec_test { + double d; + const char *fmt; + const char *rd, *rn, *rz, *ru; +}; + +static const struct dec_test dec_tests[] = { + { 1.5, "%.0f", "1", "2", "1", "2" }, + { -1.5, "%.0f", "-2", "-2", "-1", "-1" }, + { 2.5, "%.0f", "2", "2", "2", "3" }, + { -2.5, "%.0f", "-3", "-2", "-2", "-2" }, + { 1.4999, "%.0f", "1", "1", "1", "2" }, + { -1.4999, "%.0f", "-2", "-1", "-1", "-1" }, + { 1.5001, "%.0f", "1", "2", "1", "2" }, + { -1.5001, "%.0f", "-2", "-2", "-1", "-1" }, + { 2.4999, "%.0f", "2", "2", "2", "3" }, + { -2.4999, "%.0f", "-3", "-2", "-2", "-2" }, + { 2.5001, "%.0f", "2", "3", "2", "3" }, + { -2.5001, "%.0f", "-3", "-3", "-2", "-2" }, + { 1.0 / 3.0, "%f", "0.333333", "0.333333", "0.333333", "0.333334" }, + { -1.0 / 3.0, "%f", "-0.333334", "-0.333333", "-0.333333", "-0.333333" }, + { 0.2500001, "%.2e", "2.50e-01", "2.50e-01", "2.50e-01", "2.51e-01" }, + { -0.2500001, "%.2e", "-2.51e-01", "-2.50e-01", "-2.50e-01", "-2.50e-01" }, + { 1000001.0, "%.1e", "1.0e+06", "1.0e+06", "1.0e+06", "1.1e+06" }, + { -1000001.0, "%.1e", "-1.1e+06", "-1.0e+06", "-1.0e+06", "-1.0e+06" }, +}; + +static int +test_dec_in_one_mode (double d, const char *fmt, const char *expected, + const char *mode_name) +{ + char buf[100]; + int ret = snprintf (buf, sizeof buf, fmt, d); + if (ret <= 0 || ret >= (int) sizeof buf) + { + printf ("snprintf for %a returned %d\n", d, ret); + return 1; + } + if (strcmp (buf, expected) == 0) + return 0; + else + { + printf ("snprintf (\"%s\", %a) returned \"%s\" not \"%s\" (%s)\n", + fmt, d, buf, expected, mode_name); + return 1; + } +} + +static int +do_test (void) +{ + int save_round_mode = fegetround (); + int result = 0; + + for (size_t i = 0; i < sizeof (dec_tests) / sizeof (dec_tests[0]); i++) + { + result |= test_dec_in_one_mode (dec_tests[i].d, dec_tests[i].fmt, + dec_tests[i].rn, "default rounding mode"); +#ifdef FE_DOWNWARD + if (!fesetround (FE_DOWNWARD)) + { + result |= test_dec_in_one_mode (dec_tests[i].d, dec_tests[i].fmt, + dec_tests[i].rd, "FE_DOWNWARD"); + fesetround (save_round_mode); + } +#endif +#ifdef FE_TOWARDZERO + if (!fesetround (FE_TOWARDZERO)) + { + result |= test_dec_in_one_mode (dec_tests[i].d, dec_tests[i].fmt, + dec_tests[i].rz, "FE_TOWARDZERO"); + fesetround (save_round_mode); + } +#endif +#ifdef FE_UPWARD + if (!fesetround (FE_UPWARD)) + { + result |= test_dec_in_one_mode (dec_tests[i].d, dec_tests[i].fmt, + dec_tests[i].ru, "FE_UPWARD"); + fesetround (save_round_mode); + } +#endif + } + return result; +} + +#define TEST_FUNCTION do_test () +#include "../test-skeleton.c" |