// SPDX-License-Identifier: GPL-2.0-or-later
/*
 * Linux/PA-RISC Project (http://www.parisc-linux.org/)
 *
 * Floating-point emulation code
 *  Copyright (C) 2001 Hewlett-Packard (Paul Bame) <bame@debian.org>
 */
/*
 * BEGIN_DESC
 *
 *  File:
 *      @(#)    pa/spmath/fcnvfx.c              $Revision: 1.1 $
 *
 *  Purpose:
 *      Single Floating-point to Single Fixed-point
 *      Single Floating-point to Double Fixed-point 
 *      Double Floating-point to Single Fixed-point 
 *      Double Floating-point to Double Fixed-point 
 *
 *  External Interfaces:
 *      dbl_to_dbl_fcnvfx(srcptr,_nullptr,dstptr,status)
 *      dbl_to_sgl_fcnvfx(srcptr,_nullptr,dstptr,status)
 *      sgl_to_dbl_fcnvfx(srcptr,_nullptr,dstptr,status)
 *      sgl_to_sgl_fcnvfx(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 Single Fixed-point 
 */
/*ARGSUSED*/
int
sgl_to_sgl_fcnvfx(
                    sgl_floating_point *srcptr,
                    sgl_floating_point *_nullptr,
                    int *dstptr,
                    sgl_floating_point *status)
{
        register unsigned int src, temp;
        register int src_exponent, result;
        register boolean inexact = FALSE;

        src = *srcptr;
        src_exponent = Sgl_exponent(src) - SGL_BIAS;

        /* 
         * Test for overflow
         */
        if (src_exponent > SGL_FX_MAX_EXP) {
                /* check for MININT */
                if ((src_exponent > SGL_FX_MAX_EXP + 1) || 
                Sgl_isnotzero_mantissa(src) || Sgl_iszero_sign(src)) {
                        if (Sgl_iszero_sign(src)) result = 0x7fffffff;
                        else result = 0x80000000; 

                        if (Is_invalidtrap_enabled()) {
                            return(INVALIDEXCEPTION);
                        }
                        Set_invalidflag();
                        *dstptr = result;
                        return(NOEXCEPTION);
                }
        }
        /*
         * Generate result
         */
        if (src_exponent >= 0) {
                temp = src;
                Sgl_clear_signexponent_set_hidden(temp);
                Int_from_sgl_mantissa(temp,src_exponent);
                if (Sgl_isone_sign(src))  result = -Sgl_all(temp);
                else result = Sgl_all(temp);

                /* 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)) result++;
                             break;
                        case ROUNDMINUS:
                             if (Sgl_isone_sign(src)) result--;
                             break;
                        case ROUNDNEAREST:
                             if (Sgl_isone_roundbit(src,src_exponent)) {
                                if (Sgl_isone_stickybit(src,src_exponent) 
                                || (Sgl_isone_lowmantissa(temp)))
                                   if (Sgl_iszero_sign(src)) result++;
                                   else result--;
                             }
                        } 
                }
        }
        else {
                result = 0;

                /* check for inexact */
                if (Sgl_isnotzero_exponentmantissa(src)) {
                        inexact = TRUE;
                        /*  round result  */
                        switch (Rounding_mode()) {
                        case ROUNDPLUS:
                             if (Sgl_iszero_sign(src)) result++;
                             break;
                        case ROUNDMINUS:
                             if (Sgl_isone_sign(src)) result--;
                             break;
                        case ROUNDNEAREST:
                             if (src_exponent == -1)
                                if (Sgl_isnotzero_mantissa(src))
                                   if (Sgl_iszero_sign(src)) result++;
                                   else result--;
                        } 
                }
        }
        *dstptr = result;
        if (inexact) {
                if (Is_inexacttrap_enabled()) return(INEXACTEXCEPTION);
                else Set_inexactflag();
        }
        return(NOEXCEPTION);
}

/*
 *  Single Floating-point to Double Fixed-point 
 */
/*ARGSUSED*/
int
sgl_to_dbl_fcnvfx(
                sgl_floating_point *srcptr,
                unsigned int *_nullptr,
                dbl_integer *dstptr,
                unsigned int *status)
{
        register int src_exponent, resultp1;
        register unsigned int src, temp, resultp2;
        register boolean inexact = FALSE;

        src = *srcptr;
        src_exponent = Sgl_exponent(src) - SGL_BIAS;

        /* 
         * Test for overflow
         */
        if (src_exponent > DBL_FX_MAX_EXP) {
                /* check for MININT */
                if ((src_exponent > DBL_FX_MAX_EXP + 1) || 
                Sgl_isnotzero_mantissa(src) || Sgl_iszero_sign(src)) {
                        if (Sgl_iszero_sign(src)) {
                              resultp1 = 0x7fffffff;
                              resultp2 = 0xffffffff;
                        }
                        else {
                            resultp1 = 0x80000000; 
                            resultp2 = 0;
                        }
                        if (Is_invalidtrap_enabled()) {
                            return(INVALIDEXCEPTION);
                        }
                        Set_invalidflag();
                        Dint_copytoptr(resultp1,resultp2,dstptr);
                        return(NOEXCEPTION);
                }
                Dint_set_minint(resultp1,resultp2);
                Dint_copytoptr(resultp1,resultp2,dstptr);
                return(NOEXCEPTION);
        }
        /*
         * Generate result
         */
        if (src_exponent >= 0) {
                temp = src;
                Sgl_clear_signexponent_set_hidden(temp);
                Dint_from_sgl_mantissa(temp,src_exponent,resultp1,resultp2);
                if (Sgl_isone_sign(src)) {
                        Dint_setone_sign(resultp1,resultp2);
                }

                /* 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)) {
                                Dint_increment(resultp1,resultp2);
                             }
                             break;
                        case ROUNDMINUS:
                             if (Sgl_isone_sign(src)) {
                                Dint_decrement(resultp1,resultp2);
                             }
                             break;
                        case ROUNDNEAREST:
                             if (Sgl_isone_roundbit(src,src_exponent))
                                if (Sgl_isone_stickybit(src,src_exponent) || 
                                (Dint_isone_lowp2(resultp2)))
                                   if (Sgl_iszero_sign(src)) {
                                      Dint_increment(resultp1,resultp2);
                                   }
                                   else {
                                      Dint_decrement(resultp1,resultp2);
                                   }
                        }
                }
        }
        else {
                Dint_setzero(resultp1,resultp2);

                /* check for inexact */
                if (Sgl_isnotzero_exponentmantissa(src)) {
                        inexact = TRUE;
                        /*  round result  */
                        switch (Rounding_mode()) {
                        case ROUNDPLUS:
                             if (Sgl_iszero_sign(src)) {
                                Dint_increment(resultp1,resultp2);
                             }
                             break;
                        case ROUNDMINUS:
                             if (Sgl_isone_sign(src)) {
                                Dint_decrement(resultp1,resultp2);
                             }
                             break;
                        case ROUNDNEAREST:
                             if (src_exponent == -1)
                                if (Sgl_isnotzero_mantissa(src))
                                   if (Sgl_iszero_sign(src)) {
                                      Dint_increment(resultp1,resultp2);
                                   }
                                   else {
                                      Dint_decrement(resultp1,resultp2);
                                   }
                        }
                }
        }
        Dint_copytoptr(resultp1,resultp2,dstptr);
        if (inexact) {
                if (Is_inexacttrap_enabled()) return(INEXACTEXCEPTION);
                else Set_inexactflag();
        }
        return(NOEXCEPTION);
}

/*
 *  Double Floating-point to Single Fixed-point 
 */
/*ARGSUSED*/
int
dbl_to_sgl_fcnvfx(
                    dbl_floating_point *srcptr,
                    unsigned int *_nullptr,
                    int *dstptr,
                    unsigned int *status)
{
        register unsigned int srcp1,srcp2, tempp1,tempp2;
        register int src_exponent, result;
        register boolean inexact = FALSE;

        Dbl_copyfromptr(srcptr,srcp1,srcp2);
        src_exponent = Dbl_exponent(srcp1) - DBL_BIAS;

        /* 
         * Test for overflow
         */
        if (src_exponent > SGL_FX_MAX_EXP) {
                /* check for MININT */
                if (Dbl_isoverflow_to_int(src_exponent,srcp1,srcp2)) {
                        if (Dbl_iszero_sign(srcp1)) result = 0x7fffffff;
                        else result = 0x80000000; 

                        if (Is_invalidtrap_enabled()) {
                            return(INVALIDEXCEPTION);
                        }
                        Set_invalidflag();
                        *dstptr = result;
                        return(NOEXCEPTION);
                }
        }
        /*
         * Generate result
         */
        if (src_exponent >= 0) {
                tempp1 = srcp1;
                tempp2 = srcp2;
                Dbl_clear_signexponent_set_hidden(tempp1);
                Int_from_dbl_mantissa(tempp1,tempp2,src_exponent);
                if (Dbl_isone_sign(srcp1) && (src_exponent <= SGL_FX_MAX_EXP))
                        result = -Dbl_allp1(tempp1);
                else result = Dbl_allp1(tempp1);

                /* 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)) result++;
                             break;
                        case ROUNDMINUS:
                             if (Dbl_isone_sign(srcp1)) result--;
                             break;
                        case ROUNDNEAREST:
                             if (Dbl_isone_roundbit(srcp1,srcp2,src_exponent))
                                if (Dbl_isone_stickybit(srcp1,srcp2,src_exponent) || 
                                (Dbl_isone_lowmantissap1(tempp1)))
                                   if (Dbl_iszero_sign(srcp1)) result++;
                                   else result--;
                        } 
                        /* check for overflow */
                        if ((Dbl_iszero_sign(srcp1) && result < 0) ||
                            (Dbl_isone_sign(srcp1) && result > 0)) {
                                
                          if (Dbl_iszero_sign(srcp1)) result = 0x7fffffff;
                          else result = 0x80000000; 

                          if (Is_invalidtrap_enabled()) {
                            return(INVALIDEXCEPTION);
                          }
                          Set_invalidflag();
                          *dstptr = result;
                          return(NOEXCEPTION);
                        }
                }
        }
        else {
                result = 0;

                /* check for inexact */
                if (Dbl_isnotzero_exponentmantissa(srcp1,srcp2)) {
                        inexact = TRUE;
                        /*  round result  */
                        switch (Rounding_mode()) {
                        case ROUNDPLUS:
                             if (Dbl_iszero_sign(srcp1)) result++;
                             break;
                        case ROUNDMINUS:
                             if (Dbl_isone_sign(srcp1)) result--;
                             break;
                        case ROUNDNEAREST:
                             if (src_exponent == -1)
                                if (Dbl_isnotzero_mantissa(srcp1,srcp2))
                                   if (Dbl_iszero_sign(srcp1)) result++;
                                   else result--;
                        }
                }
        }
        *dstptr = result;
        if (inexact) {
                if (Is_inexacttrap_enabled()) return(INEXACTEXCEPTION);
                else Set_inexactflag();
        }
        return(NOEXCEPTION);
}

/*
 *  Double Floating-point to Double Fixed-point 
 */
/*ARGSUSED*/
int
dbl_to_dbl_fcnvfx(
                    dbl_floating_point *srcptr,
                    unsigned int *_nullptr,
                    dbl_integer *dstptr,
                    unsigned int *status)
{
        register int src_exponent, resultp1;
        register unsigned int srcp1, srcp2, tempp1, tempp2, resultp2;
        register boolean inexact = FALSE;

        Dbl_copyfromptr(srcptr,srcp1,srcp2);
        src_exponent = Dbl_exponent(srcp1) - DBL_BIAS;

        /* 
         * Test for overflow
         */
        if (src_exponent > DBL_FX_MAX_EXP) {
                /* check for MININT */
                if ((src_exponent > DBL_FX_MAX_EXP + 1) || 
                Dbl_isnotzero_mantissa(srcp1,srcp2) || Dbl_iszero_sign(srcp1)) {
                        if (Dbl_iszero_sign(srcp1)) {
                              resultp1 = 0x7fffffff;
                              resultp2 = 0xffffffff;
                        }
                        else {
                            resultp1 = 0x80000000; 
                            resultp2 = 0;
                        }
                        if (Is_invalidtrap_enabled()) {
                            return(INVALIDEXCEPTION);
                        }
                        Set_invalidflag();
                        Dint_copytoptr(resultp1,resultp2,dstptr);
                        return(NOEXCEPTION);
                }
        }
 
        /*
         * Generate result
         */
        if (src_exponent >= 0) {
                tempp1 = srcp1;
                tempp2 = srcp2;
                Dbl_clear_signexponent_set_hidden(tempp1);
                Dint_from_dbl_mantissa(tempp1,tempp2,src_exponent,resultp1,
                resultp2);
                if (Dbl_isone_sign(srcp1)) {
                        Dint_setone_sign(resultp1,resultp2);
                }

                /* 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)) {
                                Dint_increment(resultp1,resultp2);
                             }
                             break;
                        case ROUNDMINUS:
                             if (Dbl_isone_sign(srcp1)) {
                                Dint_decrement(resultp1,resultp2);
                             }
                             break;
                        case ROUNDNEAREST:
                             if (Dbl_isone_roundbit(srcp1,srcp2,src_exponent))
                                if (Dbl_isone_stickybit(srcp1,srcp2,src_exponent) || 
                                (Dint_isone_lowp2(resultp2)))
                                   if (Dbl_iszero_sign(srcp1)) {
                                      Dint_increment(resultp1,resultp2);
                                   }
                                   else {
                                      Dint_decrement(resultp1,resultp2);
                                   }
                        } 
                }
        }
        else {
                Dint_setzero(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)) {
                                Dint_increment(resultp1,resultp2);
                             }
                             break;
                        case ROUNDMINUS:
                             if (Dbl_isone_sign(srcp1)) {
                                Dint_decrement(resultp1,resultp2);
                             }
                             break;
                        case ROUNDNEAREST:
                             if (src_exponent == -1)
                                if (Dbl_isnotzero_mantissa(srcp1,srcp2))
                                   if (Dbl_iszero_sign(srcp1)) {
                                      Dint_increment(resultp1,resultp2);
                                   }
                                   else {
                                      Dint_decrement(resultp1,resultp2);
                                   }
                        }
                }
        }
        Dint_copytoptr(resultp1,resultp2,dstptr);
        if (inexact) {
                if (Is_inexacttrap_enabled()) return(INEXACTEXCEPTION);
                else Set_inexactflag();
        }
        return(NOEXCEPTION);
}