mirror of https://github.com/flysand7/ciabatta.git
48 lines
1.3 KiB
C
48 lines
1.3 KiB
C
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#include <stdio.h>
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#include <math.h>
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#include <fenv.h>
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#include <emmintrin.h>
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#pragma STDC FENV_ACCESS ON
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static inline double rint (double const x) {
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return (double)_mm_cvtsd_si32(_mm_load_sd(&x));
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}
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void show_fe_current_rounding_direction(void)
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{
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printf("current rounding direction: ");
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switch (fegetround()) {
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case FE_TONEAREST: printf ("FE_TONEAREST"); break;
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case FE_DOWNWARD: printf ("FE_DOWNWARD"); break;
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case FE_UPWARD: printf ("FE_UPWARD"); break;
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case FE_TOWARDZERO: printf ("FE_TOWARDZERO"); break;
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default: printf ("unknown");
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};
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printf("\n");
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}
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int main(void)
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{
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/* Default rounding direction */
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show_fe_current_rounding_direction();
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printf("+11.5 -> %f\n", rint(+11.5)); /* midway between two integers */
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printf("+12.5 -> %f\n", rint(+12.5)); /* midway between two integers */
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/* Save current rounding direction. */
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int curr_direction = fegetround();
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/* Temporarily change current rounding direction. */
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fesetround(FE_DOWNWARD);
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show_fe_current_rounding_direction();
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printf("+11.5 -> %f\n", rint(+11.5));
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printf("+12.5 -> %f\n", rint(+12.5));
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/* Restore default rounding direction. */
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fesetround(curr_direction);
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show_fe_current_rounding_direction();
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return 0;
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}
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