/*	$OpenBSD: frnd.c,v 1.9 2023/03/08 04:43:07 guenther Exp $	*/
/*
  (c) Copyright 1986 HEWLETT-PACKARD COMPANY
  To anyone who acknowledges that this file is provided "AS IS"
  without any express or implied warranty:
      permission to use, copy, modify, and distribute this file
  for any purpose is hereby granted without fee, provided that
  the above copyright notice and this notice appears in all
  copies, and that the name of Hewlett-Packard Company not be
  used in advertising or publicity pertaining to distribution
  of the software without specific, written prior permission.
  Hewlett-Packard Company makes no representations about the
  suitability of this software for any purpose.
*/
/* @(#)frnd.c: Revision: 2.7.88.1 Date: 93/12/07 15:06:24 */

#include "float.h"
#include "sgl_float.h"
#include "dbl_float.h"
#include "quad_float.h"
#include "cnv_float.h"

/*
 *  Single Floating-point Round to Integer
 */

int
sgl_frnd(srcptr, null, dstptr, status)
	sgl_floating_point *srcptr, *null, *dstptr;
	unsigned int *status;
{
	register unsigned int src, result;
	register int src_exponent;
	register int inexact = FALSE;

	src = *srcptr;
	/*
	 * check source operand for NaN or infinity
	 */
	if ((src_exponent = Sgl_exponent(src)) == SGL_INFINITY_EXPONENT) {
		/*
		 * is signaling NaN?
		 */
		if (Sgl_isone_signaling(src)) {
			/* trap if INVALIDTRAP enabled */
			if (Is_invalidtrap_enabled()) return(INVALIDEXCEPTION);
			/* make NaN quiet */
			Set_invalidflag();
			Sgl_set_quiet(src);
		}
		/*
		 * return quiet NaN or infinity
		 */
		*dstptr = src;
		return(NOEXCEPTION);
	}
	/*
	 * Need to round?
	 */
	if ((src_exponent -= SGL_BIAS) >= SGL_P - 1) {
		*dstptr = src;
		return(NOEXCEPTION);
	}
	/*
	 * Generate result
	 */
	if (src_exponent >= 0) {
		Sgl_clear_exponent_set_hidden(src);
		result = src;
		Sgl_rightshift(result,(SGL_P-1) - (src_exponent));
		/* check for inexact */
		if (Sgl_isinexact_to_fix(src,src_exponent)) {
			inexact = TRUE;
			/*  round result  */
			switch (Rounding_mode()) {
			case ROUNDPLUS:
			     if (Sgl_iszero_sign(src)) Sgl_increment(result);
			     break;
			case ROUNDMINUS:
			     if (Sgl_isone_sign(src)) Sgl_increment(result);
			     break;
			case ROUNDNEAREST:
			     if (Sgl_isone_roundbit(src,src_exponent))
				if (Sgl_isone_stickybit(src,src_exponent)
				|| (Sgl_isone_lowmantissa(result)))
					Sgl_increment(result);
			}
		}
		Sgl_leftshift(result,(SGL_P-1) - (src_exponent));
		if (Sgl_isone_hiddenoverflow(result))
			Sgl_set_exponent(result,src_exponent + (SGL_BIAS+1));
		else Sgl_set_exponent(result,src_exponent + SGL_BIAS);
	}
	else {
		result = src;		/* set sign */
		Sgl_setzero_exponentmantissa(result);
		/* check for inexact */
		if (Sgl_isnotzero_exponentmantissa(src)) {
			inexact = TRUE;
			/*  round result  */
			switch (Rounding_mode()) {
			case ROUNDPLUS:
			     if (Sgl_iszero_sign(src))
				Sgl_set_exponent(result,SGL_BIAS);
			     break;
			case ROUNDMINUS:
			     if (Sgl_isone_sign(src))
				Sgl_set_exponent(result,SGL_BIAS);
			     break;
			case ROUNDNEAREST:
			     if (src_exponent == -1)
				if (Sgl_isnotzero_mantissa(src))
				   Sgl_set_exponent(result,SGL_BIAS);
			}
		}
	}
	*dstptr = result;
	if (inexact) {
		if (Is_inexacttrap_enabled()) return(INEXACTEXCEPTION);
		else Set_inexactflag();
	}
	return(NOEXCEPTION);
}

/*
 *  Double Floating-point Round to Integer
 */

int
dbl_frnd(srcptr, null, dstptr, status)
	dbl_floating_point *srcptr, *null, *dstptr;
	unsigned int *status;
{
	register unsigned int srcp1, srcp2, resultp1, resultp2;
	register int src_exponent;
	register int inexact = FALSE;

	Dbl_copyfromptr(srcptr,srcp1,srcp2);
	/*
	 * check source operand for NaN or infinity
	 */
	if ((src_exponent = Dbl_exponent(srcp1)) == DBL_INFINITY_EXPONENT) {
		/*
		 * is signaling NaN?
		 */
		if (Dbl_isone_signaling(srcp1)) {
			/* trap if INVALIDTRAP enabled */
			if (Is_invalidtrap_enabled()) return(INVALIDEXCEPTION);
			/* make NaN quiet */
			Set_invalidflag();
			Dbl_set_quiet(srcp1);
		}
		/*
		 * return quiet NaN or infinity
		 */
		Dbl_copytoptr(srcp1,srcp2,dstptr);
		return(NOEXCEPTION);
	}
	/*
	 * Need to round?
	 */
	if ((src_exponent -= DBL_BIAS) >= DBL_P - 1) {
		Dbl_copytoptr(srcp1,srcp2,dstptr);
		return(NOEXCEPTION);
	}
	/*
	 * Generate result
	 */
	if (src_exponent >= 0) {
		Dbl_clear_exponent_set_hidden(srcp1);
		resultp1 = srcp1;
		resultp2 = srcp2;
		Dbl_rightshift(resultp1,resultp2,(DBL_P-1) - (src_exponent));
		/* check for inexact */
		if (Dbl_isinexact_to_fix(srcp1,srcp2,src_exponent)) {
			inexact = TRUE;
			/*  round result  */
			switch (Rounding_mode()) {
			case ROUNDPLUS:
			     if (Dbl_iszero_sign(srcp1))
				Dbl_increment(resultp1,resultp2);
			     break;
			case ROUNDMINUS:
			     if (Dbl_isone_sign(srcp1))
				Dbl_increment(resultp1,resultp2);
			     break;
			case ROUNDNEAREST:
			     if (Dbl_isone_roundbit(srcp1,srcp2,src_exponent))
			      if (Dbl_isone_stickybit(srcp1,srcp2,src_exponent)
				  || (Dbl_isone_lowmantissap2(resultp2)))
					Dbl_increment(resultp1,resultp2);
			}
		}
		Dbl_leftshift(resultp1,resultp2,(DBL_P-1) - (src_exponent));
		if (Dbl_isone_hiddenoverflow(resultp1))
			Dbl_set_exponent(resultp1,src_exponent + (DBL_BIAS+1));
		else Dbl_set_exponent(resultp1,src_exponent + DBL_BIAS);
	}
	else {
		resultp1 = srcp1;  /* set sign */
		Dbl_setzero_exponentmantissa(resultp1,resultp2);
		/* check for inexact */
		if (Dbl_isnotzero_exponentmantissa(srcp1,srcp2)) {
			inexact = TRUE;
			/*  round result  */
			switch (Rounding_mode()) {
			case ROUNDPLUS:
			     if (Dbl_iszero_sign(srcp1))
				Dbl_set_exponent(resultp1,DBL_BIAS);
			     break;
			case ROUNDMINUS:
			     if (Dbl_isone_sign(srcp1))
				Dbl_set_exponent(resultp1,DBL_BIAS);
			     break;
			case ROUNDNEAREST:
			     if (src_exponent == -1)
				if (Dbl_isnotzero_mantissa(srcp1,srcp2))
				   Dbl_set_exponent(resultp1,DBL_BIAS);
			}
		}
	}
	Dbl_copytoptr(resultp1,resultp2,dstptr);
	if (inexact) {
		if (Is_inexacttrap_enabled()) return(INEXACTEXCEPTION);
		else Set_inexactflag();
	}
	return(NOEXCEPTION);
}

int
quad_frnd(srcptr, null, dstptr, status)
	quad_floating_point *srcptr, *null, *dstptr;
	unsigned int *status;
{
	return(UNIMPLEMENTEDEXCEPTION);
}