374 lines
9.0 KiB
C
374 lines
9.0 KiB
C
|
// 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/fcnvxf.c $Revision: 1.1 $
|
||
|
|
*
|
||
|
|
* Purpose:
|
||
|
|
* Single Fixed-point to Single Floating-point
|
||
|
|
* Single Fixed-point to Double Floating-point
|
||
|
|
* Double Fixed-point to Single Floating-point
|
||
|
|
* Double Fixed-point to Double Floating-point
|
||
|
|
*
|
||
|
|
* External Interfaces:
|
||
|
|
* dbl_to_dbl_fcnvxf(srcptr,nullptr,dstptr,status)
|
||
|
|
* dbl_to_sgl_fcnvxf(srcptr,nullptr,dstptr,status)
|
||
|
|
* sgl_to_dbl_fcnvxf(srcptr,nullptr,dstptr,status)
|
||
|
|
* sgl_to_sgl_fcnvxf(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"
|
||
|
|
|
||
|
|
/*
|
||
|
|
* Convert single fixed-point to single floating-point format
|
||
|
|
*/
|
||
|
|
|
||
|
|
int
|
||
|
|
sgl_to_sgl_fcnvxf(
|
||
|
|
int *srcptr,
|
||
|
|
unsigned int *nullptr,
|
||
|
|
sgl_floating_point *dstptr,
|
||
|
|
unsigned int *status)
|
||
|
|
{
|
||
|
|
register int src, dst_exponent;
|
||
|
|
register unsigned int result = 0;
|
||
|
|
|
||
|
|
src = *srcptr;
|
||
|
|
/*
|
||
|
|
* set sign bit of result and get magnitude of source
|
||
|
|
*/
|
||
|
|
if (src < 0) {
|
||
|
|
Sgl_setone_sign(result);
|
||
|
|
Int_negate(src);
|
||
|
|
}
|
||
|
|
else {
|
||
|
|
Sgl_setzero_sign(result);
|
||
|
|
/* Check for zero */
|
||
|
|
if (src == 0) {
|
||
|
|
Sgl_setzero(result);
|
||
|
|
*dstptr = result;
|
||
|
|
return(NOEXCEPTION);
|
||
|
|
}
|
||
|
|
}
|
||
|
|
/*
|
||
|
|
* Generate exponent and normalized mantissa
|
||
|
|
*/
|
||
|
|
dst_exponent = 16; /* initialize for normalization */
|
||
|
|
/*
|
||
|
|
* Check word for most significant bit set. Returns
|
||
|
|
* a value in dst_exponent indicating the bit position,
|
||
|
|
* between -1 and 30.
|
||
|
|
*/
|
||
|
|
Find_ms_one_bit(src,dst_exponent);
|
||
|
|
/* left justify source, with msb at bit position 1 */
|
||
|
|
if (dst_exponent >= 0) src <<= dst_exponent;
|
||
|
|
else src = 1 << 30;
|
||
|
|
Sgl_set_mantissa(result, src >> (SGL_EXP_LENGTH-1));
|
||
|
|
Sgl_set_exponent(result, 30+SGL_BIAS - dst_exponent);
|
||
|
|
|
||
|
|
/* check for inexact */
|
||
|
|
if (Int_isinexact_to_sgl(src)) {
|
||
|
|
switch (Rounding_mode()) {
|
||
|
|
case ROUNDPLUS:
|
||
|
|
if (Sgl_iszero_sign(result))
|
||
|
|
Sgl_increment(result);
|
||
|
|
break;
|
||
|
|
case ROUNDMINUS:
|
||
|
|
if (Sgl_isone_sign(result))
|
||
|
|
Sgl_increment(result);
|
||
|
|
break;
|
||
|
|
case ROUNDNEAREST:
|
||
|
|
Sgl_roundnearest_from_int(src,result);
|
||
|
|
}
|
||
|
|
if (Is_inexacttrap_enabled()) {
|
||
|
|
*dstptr = result;
|
||
|
|
return(INEXACTEXCEPTION);
|
||
|
|
}
|
||
|
|
else Set_inexactflag();
|
||
|
|
}
|
||
|
|
*dstptr = result;
|
||
|
|
return(NOEXCEPTION);
|
||
|
|
}
|
||
|
|
|
||
|
|
/*
|
||
|
|
* Single Fixed-point to Double Floating-point
|
||
|
|
*/
|
||
|
|
|
||
|
|
int
|
||
|
|
sgl_to_dbl_fcnvxf(
|
||
|
|
int *srcptr,
|
||
|
|
unsigned int *nullptr,
|
||
|
|
dbl_floating_point *dstptr,
|
||
|
|
unsigned int *status)
|
||
|
|
{
|
||
|
|
register int src, dst_exponent;
|
||
|
|
register unsigned int resultp1 = 0, resultp2 = 0;
|
||
|
|
|
||
|
|
src = *srcptr;
|
||
|
|
/*
|
||
|
|
* set sign bit of result and get magnitude of source
|
||
|
|
*/
|
||
|
|
if (src < 0) {
|
||
|
|
Dbl_setone_sign(resultp1);
|
||
|
|
Int_negate(src);
|
||
|
|
}
|
||
|
|
else {
|
||
|
|
Dbl_setzero_sign(resultp1);
|
||
|
|
/* Check for zero */
|
||
|
|
if (src == 0) {
|
||
|
|
Dbl_setzero(resultp1,resultp2);
|
||
|
|
Dbl_copytoptr(resultp1,resultp2,dstptr);
|
||
|
|
return(NOEXCEPTION);
|
||
|
|
}
|
||
|
|
}
|
||
|
|
/*
|
||
|
|
* Generate exponent and normalized mantissa
|
||
|
|
*/
|
||
|
|
dst_exponent = 16; /* initialize for normalization */
|
||
|
|
/*
|
||
|
|
* Check word for most significant bit set. Returns
|
||
|
|
* a value in dst_exponent indicating the bit position,
|
||
|
|
* between -1 and 30.
|
||
|
|
*/
|
||
|
|
Find_ms_one_bit(src,dst_exponent);
|
||
|
|
/* left justify source, with msb at bit position 1 */
|
||
|
|
if (dst_exponent >= 0) src <<= dst_exponent;
|
||
|
|
else src = 1 << 30;
|
||
|
|
Dbl_set_mantissap1(resultp1, src >> DBL_EXP_LENGTH - 1);
|
||
|
|
Dbl_set_mantissap2(resultp2, src << (33-DBL_EXP_LENGTH));
|
||
|
|
Dbl_set_exponent(resultp1, (30+DBL_BIAS) - dst_exponent);
|
||
|
|
Dbl_copytoptr(resultp1,resultp2,dstptr);
|
||
|
|
return(NOEXCEPTION);
|
||
|
|
}
|
||
|
|
|
||
|
|
/*
|
||
|
|
* Double Fixed-point to Single Floating-point
|
||
|
|
*/
|
||
|
|
|
||
|
|
int
|
||
|
|
dbl_to_sgl_fcnvxf(
|
||
|
|
dbl_integer *srcptr,
|
||
|
|
unsigned int *nullptr,
|
||
|
|
sgl_floating_point *dstptr,
|
||
|
|
unsigned int *status)
|
||
|
|
{
|
||
|
|
int dst_exponent, srcp1;
|
||
|
|
unsigned int result = 0, srcp2;
|
||
|
|
|
||
|
|
Dint_copyfromptr(srcptr,srcp1,srcp2);
|
||
|
|
/*
|
||
|
|
* set sign bit of result and get magnitude of source
|
||
|
|
*/
|
||
|
|
if (srcp1 < 0) {
|
||
|
|
Sgl_setone_sign(result);
|
||
|
|
Dint_negate(srcp1,srcp2);
|
||
|
|
}
|
||
|
|
else {
|
||
|
|
Sgl_setzero_sign(result);
|
||
|
|
/* Check for zero */
|
||
|
|
if (srcp1 == 0 && srcp2 == 0) {
|
||
|
|
Sgl_setzero(result);
|
||
|
|
*dstptr = result;
|
||
|
|
return(NOEXCEPTION);
|
||
|
|
}
|
||
|
|
}
|
||
|
|
/*
|
||
|
|
* Generate exponent and normalized mantissa
|
||
|
|
*/
|
||
|
|
dst_exponent = 16; /* initialize for normalization */
|
||
|
|
if (srcp1 == 0) {
|
||
|
|
/*
|
||
|
|
* Check word for most significant bit set. Returns
|
||
|
|
* a value in dst_exponent indicating the bit position,
|
||
|
|
* between -1 and 30.
|
||
|
|
*/
|
||
|
|
Find_ms_one_bit(srcp2,dst_exponent);
|
||
|
|
/* left justify source, with msb at bit position 1 */
|
||
|
|
if (dst_exponent >= 0) {
|
||
|
|
srcp1 = srcp2 << dst_exponent;
|
||
|
|
srcp2 = 0;
|
||
|
|
}
|
||
|
|
else {
|
||
|
|
srcp1 = srcp2 >> 1;
|
||
|
|
srcp2 <<= 31;
|
||
|
|
}
|
||
|
|
/*
|
||
|
|
* since msb set is in second word, need to
|
||
|
|
* adjust bit position count
|
||
|
|
*/
|
||
|
|
dst_exponent += 32;
|
||
|
|
}
|
||
|
|
else {
|
||
|
|
/*
|
||
|
|
* Check word for most significant bit set. Returns
|
||
|
|
* a value in dst_exponent indicating the bit position,
|
||
|
|
* between -1 and 30.
|
||
|
|
*
|
||
|
|
*/
|
||
|
|
Find_ms_one_bit(srcp1,dst_exponent);
|
||
|
|
/* left justify source, with msb at bit position 1 */
|
||
|
|
if (dst_exponent > 0) {
|
||
|
|
Variable_shift_double(srcp1,srcp2,(32-dst_exponent),
|
||
|
|
srcp1);
|
||
|
|
srcp2 <<= dst_exponent;
|
||
|
|
}
|
||
|
|
/*
|
||
|
|
* If dst_exponent = 0, we don't need to shift anything.
|
||
|
|
* If dst_exponent = -1, src = - 2**63 so we won't need to
|
||
|
|
* shift srcp2.
|
||
|
|
*/
|
||
|
|
else srcp1 >>= -(dst_exponent);
|
||
|
|
}
|
||
|
|
Sgl_set_mantissa(result, srcp1 >> SGL_EXP_LENGTH - 1);
|
||
|
|
Sgl_set_exponent(result, (62+SGL_BIAS) - dst_exponent);
|
||
|
|
|
||
|
|
/* check for inexact */
|
||
|
|
if (Dint_isinexact_to_sgl(srcp1,srcp2)) {
|
||
|
|
switch (Rounding_mode()) {
|
||
|
|
case ROUNDPLUS:
|
||
|
|
if (Sgl_iszero_sign(result))
|
||
|
|
Sgl_increment(result);
|
||
|
|
break;
|
||
|
|
case ROUNDMINUS:
|
||
|
|
if (Sgl_isone_sign(result))
|
||
|
|
Sgl_increment(result);
|
||
|
|
break;
|
||
|
|
case ROUNDNEAREST:
|
||
|
|
Sgl_roundnearest_from_dint(srcp1,srcp2,result);
|
||
|
|
}
|
||
|
|
if (Is_inexacttrap_enabled()) {
|
||
|
|
*dstptr = result;
|
||
|
|
return(INEXACTEXCEPTION);
|
||
|
|
}
|
||
|
|
else Set_inexactflag();
|
||
|
|
}
|
||
|
|
*dstptr = result;
|
||
|
|
return(NOEXCEPTION);
|
||
|
|
}
|
||
|
|
|
||
|
|
/*
|
||
|
|
* Double Fixed-point to Double Floating-point
|
||
|
|
*/
|
||
|
|
|
||
|
|
int
|
||
|
|
dbl_to_dbl_fcnvxf(
|
||
|
|
dbl_integer *srcptr,
|
||
|
|
unsigned int *nullptr,
|
||
|
|
dbl_floating_point *dstptr,
|
||
|
|
unsigned int *status)
|
||
|
|
{
|
||
|
|
register int srcp1, dst_exponent;
|
||
|
|
register unsigned int srcp2, resultp1 = 0, resultp2 = 0;
|
||
|
|
|
||
|
|
Dint_copyfromptr(srcptr,srcp1,srcp2);
|
||
|
|
/*
|
||
|
|
* set sign bit of result and get magnitude of source
|
||
|
|
*/
|
||
|
|
if (srcp1 < 0) {
|
||
|
|
Dbl_setone_sign(resultp1);
|
||
|
|
Dint_negate(srcp1,srcp2);
|
||
|
|
}
|
||
|
|
else {
|
||
|
|
Dbl_setzero_sign(resultp1);
|
||
|
|
/* Check for zero */
|
||
|
|
if (srcp1 == 0 && srcp2 ==0) {
|
||
|
|
Dbl_setzero(resultp1,resultp2);
|
||
|
|
Dbl_copytoptr(resultp1,resultp2,dstptr);
|
||
|
|
return(NOEXCEPTION);
|
||
|
|
}
|
||
|
|
}
|
||
|
|
/*
|
||
|
|
* Generate exponent and normalized mantissa
|
||
|
|
*/
|
||
|
|
dst_exponent = 16; /* initialize for normalization */
|
||
|
|
if (srcp1 == 0) {
|
||
|
|
/*
|
||
|
|
* Check word for most significant bit set. Returns
|
||
|
|
* a value in dst_exponent indicating the bit position,
|
||
|
|
* between -1 and 30.
|
||
|
|
*/
|
||
|
|
Find_ms_one_bit(srcp2,dst_exponent);
|
||
|
|
/* left justify source, with msb at bit position 1 */
|
||
|
|
if (dst_exponent >= 0) {
|
||
|
|
srcp1 = srcp2 << dst_exponent;
|
||
|
|
srcp2 = 0;
|
||
|
|
}
|
||
|
|
else {
|
||
|
|
srcp1 = srcp2 >> 1;
|
||
|
|
srcp2 <<= 31;
|
||
|
|
}
|
||
|
|
/*
|
||
|
|
* since msb set is in second word, need to
|
||
|
|
* adjust bit position count
|
||
|
|
*/
|
||
|
|
dst_exponent += 32;
|
||
|
|
}
|
||
|
|
else {
|
||
|
|
/*
|
||
|
|
* Check word for most significant bit set. Returns
|
||
|
|
* a value in dst_exponent indicating the bit position,
|
||
|
|
* between -1 and 30.
|
||
|
|
*/
|
||
|
|
Find_ms_one_bit(srcp1,dst_exponent);
|
||
|
|
/* left justify source, with msb at bit position 1 */
|
||
|
|
if (dst_exponent > 0) {
|
||
|
|
Variable_shift_double(srcp1,srcp2,(32-dst_exponent),
|
||
|
|
srcp1);
|
||
|
|
srcp2 <<= dst_exponent;
|
||
|
|
}
|
||
|
|
/*
|
||
|
|
* If dst_exponent = 0, we don't need to shift anything.
|
||
|
|
* If dst_exponent = -1, src = - 2**63 so we won't need to
|
||
|
|
* shift srcp2.
|
||
|
|
*/
|
||
|
|
else srcp1 >>= -(dst_exponent);
|
||
|
|
}
|
||
|
|
Dbl_set_mantissap1(resultp1, srcp1 >> (DBL_EXP_LENGTH-1));
|
||
|
|
Shiftdouble(srcp1,srcp2,DBL_EXP_LENGTH-1,resultp2);
|
||
|
|
Dbl_set_exponent(resultp1, (62+DBL_BIAS) - dst_exponent);
|
||
|
|
|
||
|
|
/* check for inexact */
|
||
|
|
if (Dint_isinexact_to_dbl(srcp2)) {
|
||
|
|
switch (Rounding_mode()) {
|
||
|
|
case ROUNDPLUS:
|
||
|
|
if (Dbl_iszero_sign(resultp1)) {
|
||
|
|
Dbl_increment(resultp1,resultp2);
|
||
|
|
}
|
||
|
|
break;
|
||
|
|
case ROUNDMINUS:
|
||
|
|
if (Dbl_isone_sign(resultp1)) {
|
||
|
|
Dbl_increment(resultp1,resultp2);
|
||
|
|
}
|
||
|
|
break;
|
||
|
|
case ROUNDNEAREST:
|
||
|
|
Dbl_roundnearest_from_dint(srcp2,resultp1,
|
||
|
|
resultp2);
|
||
|
|
}
|
||
|
|
if (Is_inexacttrap_enabled()) {
|
||
|
|
Dbl_copytoptr(resultp1,resultp2,dstptr);
|
||
|
|
return(INEXACTEXCEPTION);
|
||
|
|
}
|
||
|
|
else Set_inexactflag();
|
||
|
|
}
|
||
|
|
Dbl_copytoptr(resultp1,resultp2,dstptr);
|
||
|
|
return(NOEXCEPTION);
|
||
|
|
}
|