25 lines
582 B
C
25 lines
582 B
C
#include <fenv.h>
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#include <math.h>
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long long
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llround (double x) {
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long long retval;
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unsigned short saved_cw, _cw;
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__asm__ (
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"fnstcw %0;" : "=m" (saved_cw)
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); /* save control word */
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_cw = ~(FE_TONEAREST | FE_DOWNWARD | FE_UPWARD | FE_TOWARDZERO)
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| (x > 0.0 ? FE_UPWARD : FE_DOWNWARD); /* round away from zero */
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__asm__ (
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"fldcw %0;" : : "m" (_cw)
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); /* load the rounding control */
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__asm__ __volatile__ (
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"fistpll %0" : "=m" (retval) : "t" (x) : "st"
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);
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__asm__ (
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"fldcw %0;" : : "m" (saved_cw)
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); /* restore control word */
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return retval;
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}
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