12116Sjkh/* s_floorf.c -- float version of s_floor.c.
22116Sjkh * Conversion to float by Ian Lance Taylor, Cygnus Support, ian@cygnus.com.
32116Sjkh */
42116Sjkh
52116Sjkh/*
62116Sjkh * ====================================================
72116Sjkh * Copyright (C) 1993 by Sun Microsystems, Inc. All rights reserved.
82116Sjkh *
92116Sjkh * Developed at SunPro, a Sun Microsystems, Inc. business.
102116Sjkh * Permission to use, copy, modify, and distribute this
118870Srgrimes * software is freely granted, provided that this notice
122116Sjkh * is preserved.
132116Sjkh * ====================================================
142116Sjkh */
152116Sjkh
16176451Sdas#include <sys/cdefs.h>
17176451Sdas__FBSDID("$FreeBSD$");
182116Sjkh
192116Sjkh/*
202116Sjkh * floorf(x)
212116Sjkh * Return x rounded toward -inf to integral value
222116Sjkh * Method:
232116Sjkh *	Bit twiddling.
242116Sjkh * Exception:
252116Sjkh *	Inexact flag raised if x not equal to floorf(x).
262116Sjkh */
272116Sjkh
282116Sjkh#include "math.h"
292116Sjkh#include "math_private.h"
302116Sjkh
312116Sjkhstatic const float huge = 1.0e30;
322116Sjkh
3397413Salfredfloat
3497413Salfredfloorf(float x)
352116Sjkh{
362116Sjkh	int32_t i0,j0;
372116Sjkh	u_int32_t i;
382116Sjkh	GET_FLOAT_WORD(i0,x);
392116Sjkh	j0 = ((i0>>23)&0xff)-0x7f;
402116Sjkh	if(j0<23) {
412116Sjkh	    if(j0<0) { 	/* raise inexact if x != 0 */
422116Sjkh		if(huge+x>(float)0.0) {/* return 0*sign(x) if |x|<1 */
438870Srgrimes		    if(i0>=0) {i0=0;}
442116Sjkh		    else if((i0&0x7fffffff)!=0)
452116Sjkh			{ i0=0xbf800000;}
462116Sjkh		}
472116Sjkh	    } else {
482116Sjkh		i = (0x007fffff)>>j0;
492116Sjkh		if((i0&i)==0) return x; /* x is integral */
502116Sjkh		if(huge+x>(float)0.0) {	/* raise inexact flag */
512116Sjkh		    if(i0<0) i0 += (0x00800000)>>j0;
522116Sjkh		    i0 &= (~i);
532116Sjkh		}
542116Sjkh	    }
552116Sjkh	} else {
562116Sjkh	    if(j0==0x80) return x+x;	/* inf or NaN */
572116Sjkh	    else return x;		/* x is integral */
582116Sjkh	}
592116Sjkh	SET_FLOAT_WORD(x,i0);
602116Sjkh	return x;
612116Sjkh}
62