/* @(#)s_floor.c 5.1 93/09/24 */ /* * ==================================================== * Copyright (C) 1993 by Sun Microsystems, Inc. All rights reserved. * * Developed at SunPro, a Sun Microsystems, Inc. business. * Permission to use, copy, modify, and distribute this * software is freely granted, provided that this notice * is preserved. * ==================================================== */ #include <sys/cdefs.h> __FBSDID("$FreeBSD$"); /* * truncf(x) * Return x rounded toward 0 to integral value * Method: * Bit twiddling. * Exception: * Inexact flag raised if x not equal to truncf(x). */ #include "math.h" #include "math_private.h" static const float huge = 1.0e30F; float truncf(float x) { int32_t i0,j0; u_int32_t i; GET_FLOAT_WORD(i0,x); j0 = ((i0>>23)&0xff)-0x7f; if(j0<23) { if(j0<0) { /* raise inexact if x != 0 */ if(huge+x>0.0F) /* |x|<1, so return 0*sign(x) */ i0 &= 0x80000000; } else { i = (0x007fffff)>>j0; if((i0&i)==0) return x; /* x is integral */ if(huge+x>0.0F) /* raise inexact flag */ i0 &= (~i); } } else { if(j0==0x80) return x+x; /* inf or NaN */ else return x; /* x is integral */ } SET_FLOAT_WORD(x,i0); return x; }