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/*
* CDDL HEADER START
*
* The contents of this file are subject to the terms of the
* Common Development and Distribution License (the "License").
* You may not use this file except in compliance with the License.
*
* You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
* or http://www.opensolaris.org/os/licensing.
* See the License for the specific language governing permissions
* and limitations under the License.
*
* When distributing Covered Code, include this CDDL HEADER in each
* file and include the License file at usr/src/OPENSOLARIS.LICENSE.
* If applicable, add the following below this CDDL HEADER, with the
* fields enclosed by brackets "[]" replaced with your own identifying
* information: Portions Copyright [yyyy] [name of copyright owner]
*
* CDDL HEADER END
*/
/*
* Copyright 2008 Sun Microsystems, Inc. All rights reserved.
* Use is subject to license terms.
*/
#pragma ident "%Z%%M% %I% %E% SMI"
#include "lint.h"
#include "base_conversion.h"
/* conversion from hex chars to hex values */
#define HEXVAL(c) (('0' <= c && c <= '9')? c - '0' : \
10 + (('a' <= c && c <= 'f')? c - 'a' : c - 'A'))
/*
* Convert a hexadecimal record in *pd to unpacked form in *pu.
*
* Up to 30 hexadecimal digits from pd->ds are converted to a binary
* value in px->significand, which is then normalized so that the most
* significant bit is 1. If there are additional, unused digits in
* pd->ds, the least significant bit of px->significand will be set.
*/
static void
__hex_to_unpacked(decimal_record *pd, unpacked *pu)
{
int i, n;
pu->sign = pd->sign;
pu->fpclass = pd->fpclass;
/*
* Adjust the (base two) exponent to reflect the fact that the
* radix point in *pd lies to the right of the last (base sixteen)
* digit while the radix point in *pu lies to the right of the
* most significant bit.
*/
pu->exponent = pd->exponent + (pd->ndigits << 2) - 1;
/* fill in the significand */
for (i = 0; i < 5; i++)
pu->significand[i] = 0;
n = pd->ndigits;
if (n > 30)
n = 30;
for (i = 0; i < n; i++) {
pu->significand[i >> 3] |= HEXVAL(pd->ds[i]) <<
((7 - (i & 7)) << 2);
}
/* sanity check */
if (pu->significand[0] == 0) {
pu->fpclass = fp_zero;
return;
}
/* normalize so the most significant bit is set */
while (pu->significand[0] < 0x80000000u) {
pu->significand[0] = (pu->significand[0] << 1) |
(pu->significand[1] >> 31);
pu->significand[1] = (pu->significand[1] << 1) |
(pu->significand[2] >> 31);
pu->significand[2] = (pu->significand[2] << 1) |
(pu->significand[3] >> 31);
pu->significand[3] <<= 1;
pu->exponent--;
}
/* if there are any unused digits, set a sticky bit */
if (pd->ndigits > 30 || pd->more)
pu->significand[4] = 1;
}
/*
* The following routines convert the hexadecimal value encoded in the
* decimal record *pd to a floating point value *px observing the round-
* ing mode specified in rd and passing back any exceptions raised via
* *ps.
*
* These routines assume pd->fpclass is either fp_zero or fp_normal.
* If pd->fpclass is fp_zero, *px is set to zero with the sign indicated
* by pd->sign and no exceptions are raised. Otherwise, pd->ds must
* contain a string of hexadecimal digits of length pd->ndigits > 0, and
* the first digit must be nonzero. Let m be the integer represented by
* this string. Then *px is set to a correctly rounded approximation to
*
* (-1)^(pd->sign) * m * 2^(pd->exponent)
*
* with inexact, underflow, and/or overflow raised as appropriate.
*/
void
__hex_to_single(decimal_record *pd, enum fp_direction_type rd, single *px,
fp_exception_field_type *ps)
{
single_equivalence kluge;
unpacked u;
*ps = 0;
if (pd->fpclass == fp_zero) {
kluge.f.msw.sign = pd->sign? 1 : 0;
kluge.f.msw.exponent = 0;
kluge.f.msw.significand = 0;
*px = kluge.x;
} else {
__hex_to_unpacked(pd, &u);
__pack_single(&u, px, rd, ps);
if (*ps != 0)
__base_conversion_set_exception(*ps);
}
}
void
__hex_to_double(decimal_record *pd, enum fp_direction_type rd, double *px,
fp_exception_field_type *ps)
{
double_equivalence kluge;
unpacked u;
*ps = 0;
if (pd->fpclass == fp_zero) {
kluge.f.msw.sign = pd->sign? 1 : 0;
kluge.f.msw.exponent = 0;
kluge.f.msw.significand = 0;
kluge.f.significand2 = 0;
*px = kluge.x;
} else {
__hex_to_unpacked(pd, &u);
__pack_double(&u, px, rd, ps);
if (*ps != 0)
__base_conversion_set_exception(*ps);
}
}
#if defined(__sparc)
void
__hex_to_quadruple(decimal_record *pd, enum fp_direction_type rd, quadruple *px,
fp_exception_field_type *ps)
{
quadruple_equivalence kluge;
unpacked u;
*ps = 0;
if (pd->fpclass == fp_zero) {
kluge.f.msw.sign = pd->sign? 1 : 0;
kluge.f.msw.exponent = 0;
kluge.f.msw.significand = 0;
kluge.f.significand2 = 0;
kluge.f.significand3 = 0;
kluge.f.significand4 = 0;
*px = kluge.x;
} else {
__hex_to_unpacked(pd, &u);
__pack_quadruple(&u, px, rd, ps);
if (*ps != 0)
__base_conversion_set_exception(*ps);
}
}
#elif defined(__i386) || defined(__amd64)
void
__hex_to_extended(decimal_record *pd, enum fp_direction_type rd, extended *px,
fp_exception_field_type *ps)
{
extended_equivalence kluge;
unpacked u;
*ps = 0;
if (pd->fpclass == fp_zero) {
kluge.f.msw.sign = pd->sign? 1 : 0;
kluge.f.msw.exponent = 0;
kluge.f.significand = 0;
kluge.f.significand2 = 0;
(*px)[0] = kluge.x[0];
(*px)[1] = kluge.x[1];
(*px)[2] = kluge.x[2];
} else {
__hex_to_unpacked(pd, &u);
__pack_extended(&u, px, rd, ps);
if (*ps != 0)
__base_conversion_set_exception(*ps);
}
}
#else
#error Unknown architecture
#endif
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