sysdeps/ieee754/flt-32/s_isinff.c

   1 /*
   2  * Public domain.
   3  */
   4
   5 #if defined(LIBM_SCCS) && !defined(lint)
   6 static char rcsid[] = "$NetBSD: s_isinff.c,v 1.3 1995/05/11 23:20:21 jtc Exp $";
   7 #endif
   8
   9 /*
  10  * isinff(x) returns 1 if x is inf, -1 if x is -inf, else 0;
  11  * no branching!
  12  */
  13
  14 #include <math.h>
  15 #include <math_private.h>
  16
  17 int
  18 __isinff (float x)
  19 {
  20         int32_t ix,t;
  21         GET_FLOAT_WORD(ix,x);
  22         t = ix & 0x7fffffff;
  23         t ^= 0x7f800000;
  24         t |= -t;
  25         return ~(t >> 31) & (ix >> 30);
  26 }
  27 hidden_def (__isinff)
  28 weak_alias (__isinff, isinff)