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https://github.com/vale981/arb
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0244fe0e46
When rounding up, the error bound sometimes came out as 1/2 ulp instead of 1 ulp due to the mantissa rounding up to the next power of two, without a corresponding exponent correction. Fortunately, this should not affect ball arithmetic (which always rounds down).
81 lines
2.3 KiB
C
81 lines
2.3 KiB
C
/*=============================================================================
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This file is part of ARB.
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ARB is free software; you can redistribute it and/or modify
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it under the terms of the GNU General Public License as published by
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the Free Software Foundation; either version 2 of the License, or
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(at your option) any later version.
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ARB is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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GNU General Public License for more details.
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You should have received a copy of the GNU General Public License
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along with ARB; if not, write to the Free Software
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Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
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=============================================================================*/
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/******************************************************************************
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Copyright (C) 2014 Fredrik Johansson
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******************************************************************************/
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#include "fmpr.h"
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int main()
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{
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long iter;
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flint_rand_t state;
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printf("ulp....");
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fflush(stdout);
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flint_randinit(state);
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for (iter = 0; iter < 100000; iter++)
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{
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fmpr_t x, ulp, a, b;
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long prec;
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fmpr_init(x);
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fmpr_init(ulp);
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fmpr_init(a);
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fmpr_init(b);
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prec = 2 + n_randint(state, 1000);
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fmpr_randtest_not_zero(x, state, 1 + n_randint(state, 1000),
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1 + n_randint(state, 100));
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fmpr_ulp(ulp, x, prec);
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fmpr_abs(a, x);
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fmpr_mul_2exp_si(a, a, -prec);
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fmpr_abs(b, x);
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fmpr_mul_2exp_si(b, b, -prec+1);
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if (!((fmpr_cmp(a, ulp) < 0) && (fmpr_cmp(ulp, b) <= 0)))
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{
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printf("FAIL!\n");
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printf("prec = %ld\n", prec);
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printf("x = "); fmpr_print(x); printf("\n");
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printf("ulp = "); fmpr_print(ulp); printf("\n");
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printf("a = "); fmpr_print(a); printf("\n");
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printf("b = "); fmpr_print(b); printf("\n");
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abort();
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}
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fmpr_clear(x);
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fmpr_clear(ulp);
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fmpr_clear(a);
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fmpr_clear(b);
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}
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flint_randclear(state);
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flint_cleanup();
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printf("PASS\n");
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return EXIT_SUCCESS;
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}
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