[thirdparty/gcc.git] / libquadmath / math / ilogbq.c

/* s_ilogbl.c -- long double version of s_ilogb.c.
 * Conversion to IEEE quad long double by Jakub Jelinek, jj@ultra.linux.cz.
 */

/*
 * ====================================================
 * 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.
 * ====================================================
 */

#if defined(LIBM_SCCS) && !defined(lint)
static char rcsid[] = "$NetBSD: $";
#endif

/* ilogbl(long double x)
 * return the binary exponent of non-zero x
 * ilogbl(0) = FP_ILOGB0
 * ilogbl(NaN) = FP_ILOGBNAN (no signal is raised)
 * ilogbl(+-Inf) = INT_MAX (no signal is raised)
 */

#include <math.h>
#include "quadmath-imp.h"
#ifndef FP_ILOGB0
# define FP_ILOGB0 INT_MIN
#endif
#ifndef FP_ILOGBNAN
# define FP_ILOGBNAN INT_MAX
#endif

int ilogbq (__float128 x)
{
	int64_t hx,lx;
	int ix;

	GET_FLT128_WORDS64(hx,lx,x);
	hx &= 0x7fffffffffffffffLL;
	if(hx <= 0x0001000000000000LL) {
	    if((hx|lx)==0)
		{ errno = EDOM; feraiseexcept (FE_INVALID); return FP_ILOGB0; }	/* ilogbl(0) = FP_ILOGB0 */
	    else			/* subnormal x */
		if(hx==0) {
		    for (ix = -16431; lx>0; lx<<=1) ix -=1;
		} else {
		    for (ix = -16382, hx<<=15; hx>0; hx<<=1) ix -=1;
		}
	    return ix;
	}
	else if (hx<0x7fff000000000000LL) return (hx>>48)-0x3fff;
	else if (FP_ILOGBNAN != INT_MAX) {
	    /* ISO C99 requires ilogbl(+-Inf) == INT_MAX.  */
	    if (((hx^0x7fff000000000000LL)|lx) == 0)
		{ errno = EDOM; feraiseexcept (FE_INVALID); return INT_MAX; }
	}
	{ errno = EDOM; feraiseexcept (FE_INVALID); return FP_ILOGBNAN; }
}
Commit	Line	Data
e409716d	1	/* s_ilogbl.c -- long double version of s_ilogb.c.
e7b8ec29	2	* Conversion to IEEE quad long double by Jakub Jelinek, jj@ultra.linux.cz.
	3	*/
	4
	5	/*
	6	* ====================================================
	7	* Copyright (C) 1993 by Sun Microsystems, Inc. All rights reserved.
	8	*
	9	* Developed at SunPro, a Sun Microsystems, Inc. business.
	10	* Permission to use, copy, modify, and distribute this
	11	* software is freely granted, provided that this notice
	12	* is preserved.
	13	* ====================================================
	14	*/
	15
	16	#if defined(LIBM_SCCS) && !defined(lint)
	17	static char rcsid[] = "$NetBSD: $";
	18	#endif
	19
e409716d	20	/* ilogbl(long double x)
e7b8ec29	21	* return the binary exponent of non-zero x
	22	* ilogbl(0) = FP_ILOGB0
	23	* ilogbl(NaN) = FP_ILOGBNAN (no signal is raised)
	24	* ilogbl(+-Inf) = INT_MAX (no signal is raised)
	25	*/
	26
e7b8ec29	27	#include <math.h>
e7b8ec29	28	#include "quadmath-imp.h"
e7b8ec29	29	#ifndef FP_ILOGB0
	30	# define FP_ILOGB0 INT_MIN
	31	#endif
	32	#ifndef FP_ILOGBNAN
	33	# define FP_ILOGBNAN INT_MAX
	34	#endif
	35
e409716d	36	int ilogbq (__float128 x)
e7b8ec29	37	{
	38	int64_t hx,lx;
	39	int ix;
	40
	41	GET_FLT128_WORDS64(hx,lx,x);
	42	hx &= 0x7fffffffffffffffLL;
	43	if(hx <= 0x0001000000000000LL) {
	44	if((hx\|lx)==0)
e409716d	45	{ errno = EDOM; feraiseexcept (FE_INVALID); return FP_ILOGB0; } /* ilogbl(0) = FP_ILOGB0 */
e7b8ec29	46	else /* subnormal x */
	47	if(hx==0) {
	48	for (ix = -16431; lx>0; lx<<=1) ix -=1;
	49	} else {
	50	for (ix = -16382, hx<<=15; hx>0; hx<<=1) ix -=1;
	51	}
	52	return ix;
	53	}
	54	else if (hx<0x7fff000000000000LL) return (hx>>48)-0x3fff;
	55	else if (FP_ILOGBNAN != INT_MAX) {
	56	/* ISO C99 requires ilogbl(+-Inf) == INT_MAX. */
	57	if (((hx^0x7fff000000000000LL)\|lx) == 0)
e409716d	58	{ errno = EDOM; feraiseexcept (FE_INVALID); return INT_MAX; }
e7b8ec29	59	}
e409716d	60	{ errno = EDOM; feraiseexcept (FE_INVALID); return FP_ILOGBNAN; }
e7b8ec29	61	}