| /* @(#)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; |
| } |
