- 根目录:
- arch
- parisc
- math-emu
- frnd.c
/*
* 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., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*/
/*
* BEGIN_DESC
*
* Purpose:
* Single Floating-point Round to Integer
* Double Floating-point Round to Integer
* Quad Floating-point Round to Integer (returns unimplemented)
*
* External Interfaces:
* dbl_frnd(srcptr,nullptr,dstptr,status)
* sgl_frnd(srcptr,nullptr,dstptr,status)
*
* END_DESC
*/
#include "float.h"
#include "sgl_float.h"
#include "dbl_float.h"
#include "cnv_float.h"
/*
* Single Floating-point Round to Integer
*/
/*ARGSUSED*/
int
sgl_frnd(sgl_floating_point *srcptr,
unsigned int *nullptr,
sgl_floating_point *dstptr,
unsigned int *status)
{
register unsigned int src, result;
register int src_exponent;
register boolean 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
*/
/*ARGSUSED*/
int
dbl_frnd(
dbl_floating_point *srcptr,
unsigned int *nullptr,
dbl_floating_point *dstptr,
unsigned int *status)
{
register unsigned int srcp1, srcp2, resultp1, resultp2;
register int src_exponent;
register boolean 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);
}