text: /*
   * Linux/PA-RISC Project (http://www.parisc-linux.org/)
   *
   * Floating-point emulation code
   *  Copyright (C) 2001 Hewlett-Packard (Paul Bame) <bame@debian.org>
   *
   *    This program is free software; you can redistribute it and/or modify
   *    it under the terms of the GNU General Public License as published by
   *    the Free Software Foundation; either version 2, or (at your option)
   *    any later version.
   *
   *    This program is distributed in the hope that it will be useful,
   *    but WITHOUT ANY WARRANTY; without even the implied warranty of
   *    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
   *    GNU General Public License for more details.
   *
   *    You should have received a copy of the GNU General Public License
   *    along with this program; if not, write to the Free Software
   *    Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
   */
  /*
   * BEGIN_DESC
   *
   *  File:
   *	@(#)	pa/spmath/fcnvff.c		$Revision: 1.1 $
   *
   *  Purpose:
   *	Single Floating-point to Double Floating-point
   *	Double Floating-point to Single Floating-point
   *
   *  External Interfaces:
   *	dbl_to_sgl_fcnvff(srcptr,nullptr,dstptr,status)
   *	sgl_to_dbl_fcnvff(srcptr,nullptr,dstptr,status)
   *
   *  Internal Interfaces:
   *
   *  Theory:
   *	<<please update with a overview of the operation of this file>>
   *
   * END_DESC
  */
  
  
  #include "float.h"
  #include "sgl_float.h"
  #include "dbl_float.h"
  #include "cnv_float.h"
  
  /*
   *  Single Floating-point to Double Floating-point 
   */
  /*ARGSUSED*/
  int
  sgl_to_dbl_fcnvff(
  	    sgl_floating_point *srcptr,
  	    unsigned int *nullptr,
  	    dbl_floating_point *dstptr,
  	    unsigned int *status)
  {
  	register unsigned int src, resultp1, resultp2;
  	register int src_exponent;
  
  	src = *srcptr;
  	src_exponent = Sgl_exponent(src);
  	Dbl_allp1(resultp1) = Sgl_all(src);  /* set sign of result */
  	/* 
   	 * Test for NaN or infinity
   	 */
  	if (src_exponent == SGL_INFINITY_EXPONENT) {
  		/*
  		 * determine if NaN or infinity
  		 */
  		if (Sgl_iszero_mantissa(src)) {
  			/*
  			 * is infinity; want to return double infinity
  			 */
  			Dbl_setinfinity_exponentmantissa(resultp1,resultp2);
  			Dbl_copytoptr(resultp1,resultp2,dstptr);
  			return(NOEXCEPTION);
  		}
  		else {
  			/* 
  			 * is NaN; signaling or quiet?
  			 */
  			if (Sgl_isone_signaling(src)) {
  				/* trap if INVALIDTRAP enabled */
  				if (Is_invalidtrap_enabled())
  					return(INVALIDEXCEPTION);
  				/* make NaN quiet */
  				else {
  					Set_invalidflag();
  					Sgl_set_quiet(src);
  				}
  			}
  			/* 
  			 * NaN is quiet, return as double NaN 
  			 */
  			Dbl_setinfinity_exponent(resultp1);
  			Sgl_to_dbl_mantissa(src,resultp1,resultp2);
  			Dbl_copytoptr(resultp1,resultp2,dstptr);
  			return(NOEXCEPTION);
  		}
  	}
  	/* 
   	 * Test for zero or denormalized
   	 */
  	if (src_exponent == 0) {
  		/*
  		 * determine if zero or denormalized
  		 */
  		if (Sgl_isnotzero_mantissa(src)) {
  			/*
  			 * is denormalized; want to normalize
  			 */
  			Sgl_clear_signexponent(src);
  			Sgl_leftshiftby1(src);
  			Sgl_normalize(src,src_exponent);
  			Sgl_to_dbl_exponent(src_exponent,resultp1);
  			Sgl_to_dbl_mantissa(src,resultp1,resultp2);
  		}
  		else {
  			Dbl_setzero_exponentmantissa(resultp1,resultp2);
  		}
  		Dbl_copytoptr(resultp1,resultp2,dstptr);
  		return(NOEXCEPTION);
  	}
  	/*
  	 * No special cases, just complete the conversion
  	 */
  	Sgl_to_dbl_exponent(src_exponent, resultp1);
  	Sgl_to_dbl_mantissa(Sgl_mantissa(src), resultp1,resultp2);
  	Dbl_copytoptr(resultp1,resultp2,dstptr);
  	return(NOEXCEPTION);
  }
  
  /*
   *  Double Floating-point to Single Floating-point 
   */
  /*ARGSUSED*/
  int
  dbl_to_sgl_fcnvff(
  		    dbl_floating_point *srcptr,
  		    unsigned int *nullptr,
  		    sgl_floating_point *dstptr,
  		    unsigned int *status)
  {
          register unsigned int srcp1, srcp2, result;
          register int src_exponent, dest_exponent, dest_mantissa;
          register boolean inexact = FALSE, guardbit = FALSE, stickybit = FALSE;
  	register boolean lsb_odd = FALSE;
  	boolean is_tiny;
  
  	Dbl_copyfromptr(srcptr,srcp1,srcp2);
          src_exponent = Dbl_exponent(srcp1);
  	Sgl_all(result) = Dbl_allp1(srcp1);  /* set sign of result */
          /* 
           * Test for NaN or infinity
           */
          if (src_exponent == DBL_INFINITY_EXPONENT) {
                  /*
                   * determine if NaN or infinity
                   */
                  if (Dbl_iszero_mantissa(srcp1,srcp2)) {
                          /*
                           * is infinity; want to return single infinity
                           */
                          Sgl_setinfinity_exponentmantissa(result);
                          *dstptr = result;
                          return(NOEXCEPTION);
                  }
                  /* 
                   * is NaN; signaling or quiet?
                   */
                  if (Dbl_isone_signaling(srcp1)) {
                          /* trap if INVALIDTRAP enabled */
                          if (Is_invalidtrap_enabled()) return(INVALIDEXCEPTION);
                          else {
  				Set_invalidflag();
                          	/* make NaN quiet */
                          	Dbl_set_quiet(srcp1);
  			}
                  }
                  /* 
                   * NaN is quiet, return as single NaN 
                   */
                  Sgl_setinfinity_exponent(result);
  		Sgl_set_mantissa(result,Dallp1(srcp1)<<3 | Dallp2(srcp2)>>29);
  		if (Sgl_iszero_mantissa(result)) Sgl_set_quiet(result);
                  *dstptr = result;
                  return(NOEXCEPTION);
          }
          /*
           * Generate result
           */
          Dbl_to_sgl_exponent(src_exponent,dest_exponent);
  	if (dest_exponent > 0) {
          	Dbl_to_sgl_mantissa(srcp1,srcp2,dest_mantissa,inexact,guardbit, 
  		stickybit,lsb_odd);
  	}
  	else {
  		if (Dbl_iszero_exponentmantissa(srcp1,srcp2)){
  			Sgl_setzero_exponentmantissa(result);
  			*dstptr = result;
  			return(NOEXCEPTION);
  		}
                  if (Is_underflowtrap_enabled()) {
  			Dbl_to_sgl_mantissa(srcp1,srcp2,dest_mantissa,inexact,
  			guardbit,stickybit,lsb_odd);
                  }
  		else {
  			/* compute result, determine inexact info,
  			 * and set Underflowflag if appropriate
  			 */
  			Dbl_to_sgl_denormalized(srcp1,srcp2,dest_exponent,
  			dest_mantissa,inexact,guardbit,stickybit,lsb_odd,
  			is_tiny);
  		}
  	}
          /* 
           * Now round result if not exact
           */
          if (inexact) {
                  switch (Rounding_mode()) {
                          case ROUNDPLUS: 
                                  if (Sgl_iszero_sign(result)) dest_mantissa++;
                                  break;
                          case ROUNDMINUS: 
                                  if (Sgl_isone_sign(result)) dest_mantissa++;
                                  break;
                          case ROUNDNEAREST:
                                  if (guardbit) {
                                     if (stickybit || lsb_odd) dest_mantissa++;
                                     }
                  }
          }
          Sgl_set_exponentmantissa(result,dest_mantissa);
  
          /*
           * check for mantissa overflow after rounding
           */
          if ((dest_exponent>0 || Is_underflowtrap_enabled()) && 
  	    Sgl_isone_hidden(result)) dest_exponent++;
  
          /* 
           * Test for overflow
           */
          if (dest_exponent >= SGL_INFINITY_EXPONENT) {
                  /* trap if OVERFLOWTRAP enabled */
                  if (Is_overflowtrap_enabled()) {
                          /* 
                           * Check for gross overflow
                           */
                          if (dest_exponent >= SGL_INFINITY_EXPONENT+SGL_WRAP) 
                          	return(UNIMPLEMENTEDEXCEPTION);
                          
                          /*
                           * Adjust bias of result
                           */
  			Sgl_setwrapped_exponent(result,dest_exponent,ovfl);
  			*dstptr = result;
  			if (inexact) 
  			    if (Is_inexacttrap_enabled())
  				return(OVERFLOWEXCEPTION|INEXACTEXCEPTION);
  			    else Set_inexactflag();
                          return(OVERFLOWEXCEPTION);
                  }
                  Set_overflowflag();
  		inexact = TRUE;
  		/* set result to infinity or largest number */
  		Sgl_setoverflow(result);
          }
          /* 
           * Test for underflow
           */
          else if (dest_exponent <= 0) {
                  /* trap if UNDERFLOWTRAP enabled */
                  if (Is_underflowtrap_enabled()) {
                          /* 
                           * Check for gross underflow
                           */
                          if (dest_exponent <= -(SGL_WRAP))
                          	return(UNIMPLEMENTEDEXCEPTION);
                          /*
                           * Adjust bias of result
                           */
  			Sgl_setwrapped_exponent(result,dest_exponent,unfl);
  			*dstptr = result;
  			if (inexact) 
  			    if (Is_inexacttrap_enabled())
  				return(UNDERFLOWEXCEPTION|INEXACTEXCEPTION);
  			    else Set_inexactflag();
                          return(UNDERFLOWEXCEPTION);
                  }
                   /* 
                    * result is denormalized or signed zero
                    */
                 if (inexact && is_tiny) Set_underflowflag();
  
          }
  	else Sgl_set_exponent(result,dest_exponent);
  	*dstptr = result;
          /* 
           * Trap if inexact trap is enabled
           */
          if (inexact)
          	if (Is_inexacttrap_enabled()) return(INEXACTEXCEPTION);
          	else Set_inexactflag();
          return(NOEXCEPTION);
  }
  