src/math/llrintl.c

   1 #include <limits.h>
   2 #include <fenv.h>
   3 #include "libm.h"
   4
   5
   6 #if LDBL_MANT_DIG == 53 && LDBL_MAX_EXP == 1024
   7 long long llrintl(long double x)
   8 {
   9         return llrint(x);
  10 }
  11 #elif defined(FE_INEXACT)
  12 /*
  13 see comments in lrint.c
  14
  15 Note that if LLONG_MAX == 0x7fffffffffffffff && LDBL_MANT_DIG == 64
  16 then x == 2**63 - 0.5 is the only input that overflows and
  17 raises inexact (with tonearest or upward rounding mode)
  18 */
  19 long long llrintl(long double x)
  20 {
  21         #pragma STDC FENV_ACCESS ON
  22         int e;
  23
  24         e = fetestexcept(FE_INEXACT);
  25         x = rintl(x);
  26         if (!e && (x > LLONG_MAX || x < LLONG_MIN))
  27                 feclearexcept(FE_INEXACT);
  28         /* conversion */
  29         return x;
  30 }
  31 #else
  32 long long llrintl(long double x)
  33 {
  34         return rintl(x);
  35 }
  36 #endif