sysdeps/libm-ieee754/s_isinff.c

   1 /*
   2  * Written by J.T. Conklin <jtc@netbsd.org>.
   3  * Public domain.
   4  */
   5
   6 #if defined(LIBM_SCCS) && !defined(lint)
   7 static char rcsid[] = "$NetBSD: s_isinff.c,v 1.3 1995/05/11 23:20:21 jtc Exp $";
   8 #endif
   9
  10 /*
  11  * isinff(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
  19 __isinff (float x)
  20 {
  21         int32_t ix,t;
  22         GET_FLOAT_WORD(ix,x);
  23         t = ix & 0x7fffffff;
  24         t ^= 0x7f800000;
  25         t |= -t;
  26         return ~(t >> 31) & (ix >> 30);
  27 }
  28 weak_alias (__isinff, isinff)