20 lines
475 B
C
20 lines
475 B
C
#include <math.h>
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#include <limits.h>
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#include <errno.h>
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long long
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llround (double x)
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{
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/* Add +/- 0.5, then round towards zero. */
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double tmp = trunc (x + (x >= 0.0 ? 0.5 : -0.5));
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if (!isfinite (tmp)
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|| tmp > (double)LONG_LONG_MAX
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|| tmp < (double)LONG_LONG_MIN)
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{
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errno = ERANGE;
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/* Undefined behaviour, so we could return anything. */
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/* return tmp > 0.0 ? LONG_LONG_MAX : LONG_LONG_MIN; */
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}
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return (long long)tmp;
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}
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