/arch/parisc/math-emu/fcnvfu.c
https://bitbucket.org/evzijst/gittest · C · 536 lines · 393 code · 25 blank · 118 comment · 102 complexity · 9e7bfb0ce27c0927010528242e001086 MD5 · raw file
- /*
- * 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
- *
- * File:
- * @(#) pa/spmath/fcnvfu.c $Revision: 1.1 $
- *
- * Purpose:
- * Floating-point to Unsigned Fixed-point Converts
- *
- * External Interfaces:
- * dbl_to_dbl_fcnvfu(srcptr,nullptr,dstptr,status)
- * dbl_to_sgl_fcnvfu(srcptr,nullptr,dstptr,status)
- * sgl_to_dbl_fcnvfu(srcptr,nullptr,dstptr,status)
- * sgl_to_sgl_fcnvfu(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"
- /************************************************************************
- * Floating-point to Unsigned Fixed-point Converts *
- ************************************************************************/
- /*
- * Single Floating-point to Single Unsigned Fixed
- */
- /*ARGSUSED*/
- int
- sgl_to_sgl_fcnvfu(
- sgl_floating_point *srcptr,
- unsigned int *nullptr,
- unsigned int *dstptr,
- unsigned int *status)
- {
- register unsigned int src, result;
- register int src_exponent;
- register boolean inexact = FALSE;
- src = *srcptr;
- src_exponent = Sgl_exponent(src) - SGL_BIAS;
- /*
- * Test for overflow
- */
- if (src_exponent > SGL_FX_MAX_EXP + 1) {
- if (Sgl_isone_sign(src)) {
- result = 0;
- } else {
- result = 0xffffffff;
- }
- if (Is_invalidtrap_enabled()) {
- return(INVALIDEXCEPTION);
- }
- Set_invalidflag();
- *dstptr = result;
- return(NOEXCEPTION);
- }
- /*
- * Generate result
- */
- if (src_exponent >= 0) {
- /*
- * Check sign.
- * If negative, trap unimplemented.
- */
- if (Sgl_isone_sign(src)) {
- result = 0;
- if (Is_invalidtrap_enabled()) {
- return(INVALIDEXCEPTION);
- }
- Set_invalidflag();
- *dstptr = result;
- return(NOEXCEPTION);
- }
- Sgl_clear_signexponent_set_hidden(src);
- Suint_from_sgl_mantissa(src,src_exponent,result);
- /* check for inexact */
- if (Sgl_isinexact_to_unsigned(src,src_exponent)) {
- inexact = TRUE;
- /* round result */
- switch (Rounding_mode()) {
- case ROUNDPLUS:
- result++;
- break;
- case ROUNDMINUS: /* never negative */
- break;
- case ROUNDNEAREST:
- if (Sgl_isone_roundbit(src,src_exponent) &&
- (Sgl_isone_stickybit(src,src_exponent) ||
- (result & 1))) {
- result++;
- }
- break;
- }
- }
- } 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 = 0;
- if (Is_invalidtrap_enabled()) {
- return(INVALIDEXCEPTION);
- }
- Set_invalidflag();
- inexact = FALSE;
- }
- break;
- case ROUNDNEAREST:
- if (src_exponent == -1 &&
- Sgl_isnotzero_mantissa(src)) {
- if (Sgl_isone_sign(src)) {
- result = 0;
- if (Is_invalidtrap_enabled()) {
- return(INVALIDEXCEPTION);
- }
- Set_invalidflag();
- inexact = FALSE;
- }
- else result++;
- }
- break;
- }
- }
- }
- *dstptr = result;
- if (inexact) {
- if (Is_inexacttrap_enabled()) return(INEXACTEXCEPTION);
- else Set_inexactflag();
- }
- return(NOEXCEPTION);
- }
- /*
- * Single Floating-point to Double Unsigned Fixed
- */
- /*ARGSUSED*/
- int
- sgl_to_dbl_fcnvfu(
- sgl_floating_point *srcptr,
- unsigned int *nullptr,
- dbl_unsigned *dstptr,
- unsigned int *status)
- {
- register int src_exponent;
- register unsigned int src, resultp1, resultp2;
- register boolean inexact = FALSE;
- src = *srcptr;
- src_exponent = Sgl_exponent(src) - SGL_BIAS;
- /*
- * Test for overflow
- */
- if (src_exponent > DBL_FX_MAX_EXP + 1) {
- if (Sgl_isone_sign(src)) {
- resultp1 = resultp2 = 0;
- } else {
- resultp1 = resultp2 = 0xffffffff;
- }
- if (Is_invalidtrap_enabled()) {
- return(INVALIDEXCEPTION);
- }
- Set_invalidflag();
- Duint_copytoptr(resultp1,resultp2,dstptr);
- return(NOEXCEPTION);
- }
- /*
- * Generate result
- */
- if (src_exponent >= 0) {
- /*
- * Check sign.
- * If negative, trap unimplemented.
- */
- if (Sgl_isone_sign(src)) {
- resultp1 = resultp2 = 0;
- if (Is_invalidtrap_enabled()) {
- return(INVALIDEXCEPTION);
- }
- Set_invalidflag();
- Duint_copytoptr(resultp1,resultp2,dstptr);
- return(NOEXCEPTION);
- }
- Sgl_clear_signexponent_set_hidden(src);
- Duint_from_sgl_mantissa(src,src_exponent,resultp1,resultp2);
- /* check for inexact */
- if (Sgl_isinexact_to_unsigned(src,src_exponent)) {
- inexact = TRUE;
- /* round result */
- switch (Rounding_mode()) {
- case ROUNDPLUS:
- Duint_increment(resultp1,resultp2);
- break;
- case ROUNDMINUS: /* never negative */
- break;
- case ROUNDNEAREST:
- if (Sgl_isone_roundbit(src,src_exponent) &&
- (Sgl_isone_stickybit(src,src_exponent) ||
- Duint_isone_lowp2(resultp2))) {
- Duint_increment(resultp1,resultp2);
- }
- break;
- }
- }
- } else {
- Duint_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)) {
- Duint_increment(resultp1,resultp2);
- }
- break;
- case ROUNDMINUS:
- if (Sgl_isone_sign(src)) {
- resultp1 = resultp2 = 0;
- if (Is_invalidtrap_enabled()) {
- return(INVALIDEXCEPTION);
- }
- Set_invalidflag();
- inexact = FALSE;
- }
- break;
- case ROUNDNEAREST:
- if (src_exponent == -1 &&
- Sgl_isnotzero_mantissa(src)) {
- if (Sgl_isone_sign(src)) {
- resultp1 = 0;
- resultp2 = 0;
- if (Is_invalidtrap_enabled()) {
- return(INVALIDEXCEPTION);
- }
- Set_invalidflag();
- inexact = FALSE;
- }
- else Duint_increment(resultp1,resultp2);
- }
- }
- }
- }
- Duint_copytoptr(resultp1,resultp2,dstptr);
- if (inexact) {
- if (Is_inexacttrap_enabled()) return(INEXACTEXCEPTION);
- else Set_inexactflag();
- }
- return(NOEXCEPTION);
- }
- /*
- * Double Floating-point to Single Unsigned Fixed
- */
- /*ARGSUSED*/
- int
- dbl_to_sgl_fcnvfu (dbl_floating_point * srcptr, unsigned int *nullptr,
- unsigned int *dstptr, unsigned int *status)
- {
- register unsigned int srcp1, srcp2, result;
- register int src_exponent;
- 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 + 1) {
- if (Dbl_isone_sign(srcp1)) {
- result = 0;
- } else {
- result = 0xffffffff;
- }
- if (Is_invalidtrap_enabled()) {
- return(INVALIDEXCEPTION);
- }
- Set_invalidflag();
- *dstptr = result;
- return(NOEXCEPTION);
- }
- /*
- * Generate result
- */
- if (src_exponent >= 0) {
- /*
- * Check sign.
- * If negative, trap unimplemented.
- */
- if (Dbl_isone_sign(srcp1)) {
- result = 0;
- if (Is_invalidtrap_enabled()) {
- return(INVALIDEXCEPTION);
- }
- Set_invalidflag();
- *dstptr = result;
- return(NOEXCEPTION);
- }
- Dbl_clear_signexponent_set_hidden(srcp1);
- Suint_from_dbl_mantissa(srcp1,srcp2,src_exponent,result);
- /* check for inexact */
- if (Dbl_isinexact_to_unsigned(srcp1,srcp2,src_exponent)) {
- inexact = TRUE;
- /* round result */
- switch (Rounding_mode()) {
- case ROUNDPLUS:
- result++;
- break;
- case ROUNDMINUS: /* never negative */
- break;
- case ROUNDNEAREST:
- if(Dbl_isone_roundbit(srcp1,srcp2,src_exponent) &&
- (Dbl_isone_stickybit(srcp1,srcp2,src_exponent)||
- result&1))
- result++;
- break;
- }
- /* check for overflow */
- if (result == 0) {
- result = 0xffffffff;
- 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 = 0;
- if (Is_invalidtrap_enabled()) {
- return(INVALIDEXCEPTION);
- }
- Set_invalidflag();
- inexact = FALSE;
- }
- break;
- case ROUNDNEAREST:
- if (src_exponent == -1 &&
- Dbl_isnotzero_mantissa(srcp1,srcp2))
- if (Dbl_isone_sign(srcp1)) {
- result = 0;
- if (Is_invalidtrap_enabled()) {
- return(INVALIDEXCEPTION);
- }
- Set_invalidflag();
- inexact = FALSE;
- }
- else result++;
- }
- }
- }
- *dstptr = result;
- if (inexact) {
- if (Is_inexacttrap_enabled()) return(INEXACTEXCEPTION);
- else Set_inexactflag();
- }
- return(NOEXCEPTION);
- }
- /*
- * Double Floating-point to Double Unsigned Fixed
- */
- /*ARGSUSED*/
- int
- dbl_to_dbl_fcnvfu (dbl_floating_point * srcptr, unsigned int *nullptr,
- dbl_unsigned * dstptr, unsigned int *status)
- {
- register int src_exponent;
- register unsigned int srcp1, srcp2, resultp1, 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 + 1) {
- if (Dbl_isone_sign(srcp1)) {
- resultp1 = resultp2 = 0;
- } else {
- resultp1 = resultp2 = 0xffffffff;
- }
- if (Is_invalidtrap_enabled()) {
- return(INVALIDEXCEPTION);
- }
- Set_invalidflag();
- Duint_copytoptr(resultp1,resultp2,dstptr);
- return(NOEXCEPTION);
- }
-
- /*
- * Generate result
- */
- if (src_exponent >= 0) {
- /*
- * Check sign.
- * If negative, trap unimplemented.
- */
- if (Dbl_isone_sign(srcp1)) {
- resultp1 = resultp2 = 0;
- if (Is_invalidtrap_enabled()) {
- return(INVALIDEXCEPTION);
- }
- Set_invalidflag();
- Duint_copytoptr(resultp1,resultp2,dstptr);
- return(NOEXCEPTION);
- }
- Dbl_clear_signexponent_set_hidden(srcp1);
- Duint_from_dbl_mantissa(srcp1,srcp2,src_exponent,resultp1,
- resultp2);
- /* check for inexact */
- if (Dbl_isinexact_to_unsigned(srcp1,srcp2,src_exponent)) {
- inexact = TRUE;
- /* round result */
- switch (Rounding_mode()) {
- case ROUNDPLUS:
- Duint_increment(resultp1,resultp2);
- break;
- case ROUNDMINUS: /* never negative */
- break;
- case ROUNDNEAREST:
- if(Dbl_isone_roundbit(srcp1,srcp2,src_exponent))
- if(Dbl_isone_stickybit(srcp1,srcp2,src_exponent) ||
- Duint_isone_lowp2(resultp2))
- Duint_increment(resultp1,resultp2);
- }
- }
- } else {
- Duint_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)) {
- Duint_increment(resultp1,resultp2);
- }
- break;
- case ROUNDMINUS:
- if (Dbl_isone_sign(srcp1)) {
- resultp1 = resultp2 = 0;
- if (Is_invalidtrap_enabled()) {
- return(INVALIDEXCEPTION);
- }
- Set_invalidflag();
- inexact = FALSE;
- }
- break;
- case ROUNDNEAREST:
- if (src_exponent == -1 &&
- Dbl_isnotzero_mantissa(srcp1,srcp2))
- if (Dbl_iszero_sign(srcp1)) {
- Duint_increment(resultp1,resultp2);
- } else {
- resultp1 = 0;
- resultp2 = 0;
- if (Is_invalidtrap_enabled()) {
- return(INVALIDEXCEPTION);
- }
- Set_invalidflag();
- inexact = FALSE;
- }
- }
- }
- }
- Duint_copytoptr(resultp1,resultp2,dstptr);
- if (inexact) {
- if (Is_inexacttrap_enabled()) return(INEXACTEXCEPTION);
- else Set_inexactflag();
- }
- return(NOEXCEPTION);
- }