| /* @(#)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> | |
| #include <math.h> | |
| /* | |
| * 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 "../bsd_private_base.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; | |
| } |