/*

 * CDDL HEADER START

 *

 * The contents of this file are subject to the terms of the

 * Common Development and Distribution License (the "License").

 * You may not use this file except in compliance with the License.

 *

 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE

 * or http://www.opensolaris.org/os/licensing.

 * See the License for the specific language governing permissions

 * and limitations under the License.

 *

 * When distributing Covered Code, include this CDDL HEADER in each

 * file and include the License file at usr/src/OPENSOLARIS.LICENSE.

 * If applicable, add the following below this CDDL HEADER, with the

 * fields enclosed by brackets "[]" replaced with your own identifying

 * information: Portions Copyright [yyyy] [name of copyright owner]

 *

 * CDDL HEADER END

 */

/*

 * Copyright 2008 Sun Microsystems, Inc.  All rights reserved.

 * Use is subject to license terms.

 */

#pragma ident	"%Z%%M%	%I%	%E% SMI"

#include "lint.h"

#include <sys/isa_defs.h>

#include <floatingpoint.h>

#include <limits.h>

#include "libc.h"

/*

 * Ensure that this "portable" code is only used on big-endian ISAs

 */

#if !defined(_BIG_ENDIAN) || defined(_LITTLE_ENDIAN)

#error	"big-endian only!"

#endif

/*

 * Convert a double precision floating point number into a 64-bit int.

 */

long long

__dtoll(double dval)

{

	int i0, i1;		/* bitslam */

	int exp;		/* exponent */

	int m0;			/* most significant word of mantissa */

	unsigned int m1;	/* least sig. word of mantissa */

	unsigned int _fp_current_exceptions = 0;

	union {

		int i[2];

		double d;

	} u;

	/*

	 * Extract the exponent and check boundary conditions.

	 * Notice that the exponent is equal to the bit number where

	 * we want the most significant bit to live.

	 */

	u.d = dval;

	i0 = u.i[0];

	i1 = u.i[1];

	exp = ((i0 >> 20) & 0x7ff) - 0x3ff;

	if (exp < 0) {

		return ((long long)0); /* abs(x) < 1.0, so round to 0 */

	} else if (exp > 62) {

		/*

		 * fp_invalid NOT raised if <i0,i1> == LLONG_MIN

		 */

		if (i0 >= 0 || exp != 63 || (i0 & 0xfffff) != 0 || i1 != 0) {

			/*

			 * abs(x) > MAXLLONG; return {MIN,MAX}LLONG and as

			 * overflow, Inf, NaN set fp_invalid exception

			 */

			_fp_current_exceptions |= (1 << (int)fp_invalid);

			(void) _Q_set_exception(_fp_current_exceptions);

		}

		if (i0 < 0)

			return (LLONG_MIN);

		else

			return (LLONG_MAX); /* MAXLONG */

	}

	/* Extract the mantissa. */

	m0 = 0x40000000 | ((i0 << 10) & 0x3ffffc00) | ((i1 >> 22) & 0x3ff);

	m1 = i1 << 10;

	/*

	 * The most significant bit of the mantissa is now in bit 62 of m0:m1.

	 * Shift right by (62 - exp) bits.

	 */

	switch (exp) {

	case 62:

		break;

	case 30:

		m1 = m0;

		m0 = 0;

		break;

	default:

		if (exp > 30) {

			m1 = (m0 << (exp - 30)) |

			    (m1 >> (62 - exp)) & ~(-1 << (exp - 30));

			m0 >>= 62 - exp;

		} else {

			m1 = m0 >> (30 - exp);

			m0 = 0;

		}

		break;

	}

	if (i0 < 0) {

		m0 = ~m0;

		m1 = ~m1;

		if (++m1 == 0)

			m0++;

	}

	(void) _Q_set_exception(_fp_current_exceptions);

	return ((long long)(((unsigned long long)m0 << 32) | m1));

}

/*

 * Convert a floating point number into a 64-bit int.

 */

long long

__ftoll(float fval)

{

	int i0;

	int exp;		/* exponent */

	int m0;			/* most significant word of mantissa */

	unsigned int m1;	/* least sig. word of mantissa */

	unsigned int _fp_current_exceptions = 0;

	union {

		int i;

		float f;

	} u;

	/*

	 * Extract the exponent and check boundary conditions.

	 * Notice that the exponent is equal to the bit number where

	 * we want the most significant bit to live.

	 */

	u.f = fval;

	i0 = u.i;

	exp = ((i0 >> 23) & 0xff) - 0x7f;

	if (exp < 0) {

		return ((long long) 0); /* abs(x) < 1.0, so round to 0 */

	} else if (exp > 62)  {

		/*

		 * fp_invalid NOT raised if <i0> == LLONG_MIN

		 */

		if (i0 >= 0 || exp != 63 || (i0 & 0x7fffff) != 0) {

			/*

			 * abs(x) > MAXLLONG; return {MIN,MAX}LLONG and as

			 * overflow, Inf, NaN set fp_invalid exception

			 */

			_fp_current_exceptions |= (1 << (int)fp_invalid);

			(void) _Q_set_exception(_fp_current_exceptions);

		}

		if (i0 < 0)

			return (LLONG_MIN);

		else

			return (LLONG_MAX); /* MAXLONG */

	}

	/* Extract the mantissa. */

	m0 = 0x40000000 | (i0 << 7) & 0x3fffff80;

	m1 = 0;

	/*

	 * The most significant bit of the mantissa is now in bit 62 of m0:m1.

	 * Shift right by (62 - exp) bits.

	 */

	switch (exp) {

	case 62:

		break;

	case 30:

		m1 = m0;

		m0 = 0;

		break;

	default:

		if (exp > 30) {

			m1 = m0 << (exp - 30);

			m0 >>= 62 - exp;

		} else {

			m1 = m0 >> (30 - exp);

			m0 = 0;

		}

		break;

	}

	if (i0 < 0) {

		m0 = ~m0;

		m1 = ~m1;

		if (++m1 == 0)

			m0++;

	}

	(void) _Q_set_exception(_fp_current_exceptions);

	return ((long long)(((unsigned long long)m0 << 32) | m1));

}

/*

 * Convert an extended precision floating point number into a 64-bit int.

 */

long long

_Q_qtoll(long double longdbl)

{

	int i0;

	unsigned int i1, i2;	/* a long double is 128-bit in length */

	int *plngdbl = (int *)&longdbl;

	int exp;		/* exponent */

	int m0;			/* most significant word of mantissa */

	unsigned int m1;	/* least sig. word of mantissa */

	unsigned int _fp_current_exceptions = 0;

	/*

	 * Only 96-bits of precision used

	 */

	i0 = plngdbl[0];

	i1 = plngdbl[1];

	i2 = plngdbl[2];

	/*

	 * Extract the exponent and check boundary conditions.

	 * Notice that the exponent is equal to the bit number where

	 * we want the most significant bit to live.

	 */

	exp = ((i0 >> 16) & 0x7fff) - 0x3fff;

	if (exp < 0) {

		return ((long long)0); /* abs(x) < 1.0, so round to 0 */

	} else if (exp > 62)	{

		/*

		 * fp_invalid NOT raised if <i0,i1,i2,i3> when chopped to

		 * 64 bits == LLONG_MIN

		 */

		if (i0 >= 0 || exp != 63 || (i0 & 0xffff) != 0 || i1 != 0 ||

		    (i2 & 0xfffe0000) != 0) {

			/*

			 * abs(x) > MAXLLONG; return {MIN,MAX}LLONG and as

			 * overflow, Inf, NaN set fp_invalid exception

			 */

			_fp_current_exceptions |= (1 << (int)fp_invalid);

			(void) _Q_set_exception(_fp_current_exceptions);

		}

		if (i0 < 0)

			return (LLONG_MIN);

		else

			return (LLONG_MAX); /* MAXLONG */

	}

	/* Extract the mantissa. */

	m0 = 0x40000000 | ((i0 << 14) & 0x3fffc000) | ((i1 >> 18) & 0x3fff);

	m1 = (i1 << 14) | ((i2 >> 18) & 0x3fff);

	/*

	 * The most significant bit of the mantissa is now in bit 62 of m0:m1.

	 * Shift right by (62 - exp) bits.

	 */

	switch (exp) {

	case 62:

		break;

	case 30:

		m1 = m0;

		m0 = 0;

		break;

	default:

		if (exp > 30) {

			m1 = (m0 << (exp - 30)) |

			    (m1 >> (62 - exp)) & ~(-1 << (exp - 30));

			m0 >>= 62 - exp;

		} else {

			m1 = m0 >> (30 - exp);

			m0 = 0;

		}

		break;

	}

	if (i0 < 0) {

		m0 = ~m0;

		m1 = ~m1;

		if (++m1 == 0)

			m0++;

	}

	(void) _Q_set_exception(_fp_current_exceptions);

	return ((long long)(((unsigned long long)m0 << 32) | m1));

}