/* s_floorf.c -- float version of s_floor.c. * Conversion to float by Ian Lance Taylor, Cygnus Support, ian@cygnus.com. */ /* * ==================================================== * 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("$FreeBSD$"); /* * floorf(x) * Return x rounded toward -inf to integral value * Method: * Bit twiddling. * Exception: * Inexact flag raised if x not equal to floorf(x). */ #include "math.h" #include "math_private.h" static const float huge = 1.0e30; float floorf(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>(float)0.0) {/* return 0*sign(x) if |x|<1 */ if(i0>=0) {i0=0;} else if((i0&0x7fffffff)!=0) { i0=0xbf800000;} } } else { i = (0x007fffff)>>j0; if((i0&i)==0) return x; /* x is integral */ if(huge+x>(float)0.0) { /* raise inexact flag */ if(i0<0) i0 += (0x00800000)>>j0; 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; } |