sysdeps/i386/fpu/s_isinfl.c

   1 /*
   2  * Intel i387 specific version.
   3  * Public domain.
   4  */
   5
   6 #if defined(LIBM_SCCS) && !defined(lint)
   7 static char rcsid[] = "$NetBSD: $";
   8 #endif
   9
  10 /*
  11  * isinfl(x) returns 1 if x is inf, -1 if x is -inf, else 0;
  12  * no branching!
  13  */
  14
  15 #include <math.h>
  16 #include <math_private.h>
  17
  18 int __isinfl(long double x)
  19 {
  20         int32_t se,hx,lx;
  21         GET_LDOUBLE_WORDS(se,hx,lx,x);
  22         /* This additional ^ 0x80000000 is necessary because in Intel's
  23            internal representation of the implicit one is explicit.  */
  24         lx |= (hx ^ 0x80000000) | ((se & 0x7fff) ^ 0x7fff);
  25         lx |= -lx;
  26         se &= 0x8000;
  27         return ~(lx >> 31) & (1 - (se >> 14));
  28 }
  29 hidden_def (__isinfl)
  30 weak_alias (__isinfl, isinfl)