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with this work for additional information regarding copyright ownership.
Accellera licenses this file to you under the Apache License, Version 2.0
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/*****************************************************************************
scfx_rep.cpp -
Original Author: Robert Graulich, Synopsys, Inc.
Martin Janssen, Synopsys, Inc.
*****************************************************************************/
/*****************************************************************************
MODIFICATION LOG - modifiers, enter your name, affiliation, date and
changes you are making here.
Name, Affiliation, Date:
Description of Modification:
*****************************************************************************/
// $Log: scfx_rep.cpp,v $
// Revision 1.4 2011/08/24 22:05:43 acg
// Torsten Maehne: initialization changes to remove warnings.
//
// Revision 1.3 2011/08/15 16:43:24 acg
// Torsten Maehne: changes to remove unused argument warnings.
//
// Revision 1.2 2009/02/28 00:26:20 acg
// Andy Goodrich: bug fixes.
//
// Revision 1.2 2008/11/06 17:22:47 acg
// Andy Goodrich: bug fixes for 2.2.1.
//
// Revision 1.1.1.1 2006/12/15 20:31:36 acg
// SystemC 2.2
//
// Revision 1.3 2006/01/13 18:53:58 acg
// Andy Goodrich: added $Log command so that CVS comments are reproduced in
// the source.
//
#include <cctype>
#include <cmath>
#include <cstdio>
#include <cstdlib>
#include "base/compiler.hh"
#include "systemc/ext/dt/bit/sc_bv_base.hh"
#include "systemc/ext/dt/bit/sc_lv_base.hh"
#include "systemc/ext/dt/fx/scfx_ieee.hh"
#include "systemc/ext/dt/fx/scfx_pow10.hh"
#include "systemc/ext/dt/fx/scfx_rep.hh"
#include "systemc/ext/dt/fx/scfx_utils.hh"
#include "systemc/ext/utils/endian.hh"
namespace sc_dt
{
// ----------------------------------------------------------------------------
// some utilities
// ----------------------------------------------------------------------------
static scfx_pow10 pow10_fx;
static const int mantissa0_size = SCFX_IEEE_DOUBLE_M_SIZE - bits_in_int;
static inline int
n_word(int x)
{
return (x + bits_in_word - 1) / bits_in_word;
}
// ----------------------------------------------------------------------------
// CONSTRUCTORS
// ----------------------------------------------------------------------------
scfx_rep::scfx_rep() :
m_mant(min_mant), m_wp(), m_sign(), m_state(), m_msw(), m_lsw(),
m_r_flag(false)
{
set_zero();
}
scfx_rep::scfx_rep(int a) : m_mant(min_mant), m_wp(), m_sign(), m_state(),
m_msw(), m_lsw(), m_r_flag(false)
{
if (a != 0) {
m_mant.clear();
m_wp = m_msw = m_lsw = 2;
m_state = normal;
if (a > 0) {
m_mant[2] = a;
m_sign = 1;
} else {
m_mant[2] = -a;
m_sign = -1;
}
} else {
set_zero();
}
}
scfx_rep::scfx_rep(unsigned int a) : m_mant(min_mant), m_wp(), m_sign(),
m_state(), m_msw(), m_lsw(), m_r_flag(false)
{
if (a != 0) {
m_mant.clear();
m_wp = m_msw = m_lsw = 2;
m_state = normal;
m_mant[2] = a;
m_sign = 1;
} else {
set_zero();
}
}
scfx_rep::scfx_rep(long a) :
m_mant(min_mant), m_wp(), m_sign(), m_state(), m_msw(), m_lsw(),
m_r_flag(false)
{
if (a != 0) {
m_mant.clear();
m_state = normal;
if (a > 0) {
m_sign = 1;
} else {
a = -a;
m_sign = -1;
}
# if defined(SC_LONG_64)
m_wp = 1;
m_mant[1] = static_cast<word>(a);
m_mant[2] = static_cast<word>(a >> bits_in_word);
find_sw();
# else
m_wp = 2;
m_msw = 2;
m_lsw = 2;
m_mant[2] = a;
# endif
} else {
set_zero();
}
}
scfx_rep::scfx_rep(unsigned long a) :
m_mant(min_mant), m_wp(), m_sign(), m_state(), m_msw(), m_lsw(),
m_r_flag(false)
{
if (a != 0) {
m_mant.clear();
m_wp = m_msw = m_lsw = 2;
m_state = normal;
# if defined(SC_LONG_64)
m_wp = 1;
m_mant[1] = static_cast<word>(a);
m_mant[2] = static_cast<word>(a >> bits_in_word);
find_sw();
# else
m_wp = 2;
m_msw = 2;
m_lsw = 2;
m_mant[2] = a;
# endif
m_sign = 1;
}
else
set_zero();
}
scfx_rep::scfx_rep(double a) :
m_mant(min_mant), m_wp(0), m_sign(), m_state(normal), m_msw(0),
m_lsw(0), m_r_flag(false)
{
m_mant.clear();
scfx_ieee_double id(a);
m_sign = id.negative() ? -1 : 1;
if (id.is_nan()) {
m_state = not_a_number;
} else if (id.is_inf()) {
m_state = infinity;
} else if (id.is_subnormal()) {
m_mant[0] = id.mantissa1();
m_mant[1] = id.mantissa0();
normalize(id.exponent() + 1 - SCFX_IEEE_DOUBLE_M_SIZE);
} else if (id.is_normal()) {
m_mant[0] = id.mantissa1();
m_mant[1] = id.mantissa0() | (1 << mantissa0_size);
normalize(id.exponent() - SCFX_IEEE_DOUBLE_M_SIZE);
}
}
scfx_rep::scfx_rep(int64 a) :
m_mant(min_mant), m_wp(), m_sign(), m_state(), m_msw(), m_lsw(),
m_r_flag(false)
{
if (a != 0) {
m_mant.clear();
m_wp = 1;
m_state = normal;
if (a > 0) {
m_mant[1] = static_cast<word>(a);
m_mant[2] = static_cast<word>(a >> bits_in_word);
m_sign = 1;
} else {
m_mant[1] = static_cast<word>(-a);
m_mant[2] = static_cast<word>((-a) >> bits_in_word);
m_sign = -1;
}
find_sw();
} else {
set_zero();
}
}
scfx_rep::scfx_rep(uint64 a) :
m_mant(min_mant), m_wp(), m_sign(), m_state(), m_msw(), m_lsw(),
m_r_flag(false)
{
if (a != 0) {
m_mant.clear();
m_wp = 1;
m_state = normal;
m_mant[1] = static_cast<word>(a);
m_mant[2] = static_cast<word>(a >> bits_in_word);
m_sign = 1;
find_sw();
} else {
set_zero();
}
}
scfx_rep::scfx_rep(const sc_signed &a) :
m_mant(min_mant), m_wp(), m_sign(), m_state(), m_msw(), m_lsw(),
m_r_flag(false)
{
if (a.iszero()) {
set_zero();
} else {
int words = n_word(a.length());
if (words > size())
resize_to(words);
m_mant.clear();
m_wp = 0;
m_state = normal;
if (a.sign()) {
sc_signed a2 = -a;
for (int i = 0; i < a2.length(); ++i) {
if (a2[i]) {
scfx_index x = calc_indices(i);
m_mant[x.wi()] |= 1 << x.bi();
}
}
m_sign = -1;
} else {
for (int i = 0; i < a.length(); ++i) {
if (a[i]) {
scfx_index x = calc_indices(i);
m_mant[x.wi()] |= 1 << x.bi();
}
}
m_sign = 1;
}
find_sw();
}
}
scfx_rep::scfx_rep(const sc_unsigned &a) :
m_mant(min_mant), m_wp(), m_sign(), m_state(), m_msw(), m_lsw(),
m_r_flag(false)
{
if (a.iszero()) {
set_zero();
} else {
int words = n_word(a.length());
if (words > size())
resize_to(words);
m_mant.clear();
m_wp = 0;
m_state = normal;
for (int i = 0; i < a.length(); ++i) {
if (a[i]) {
scfx_index x = calc_indices(i);
m_mant[x.wi()] |= 1 << x.bi();
}
}
m_sign = 1;
find_sw();
}
}
// copy constructor
scfx_rep::scfx_rep(const scfx_rep &a) :
m_mant(a.m_mant), m_wp(a.m_wp), m_sign(a.m_sign), m_state(a.m_state),
m_msw(a.m_msw), m_lsw(a.m_lsw), m_r_flag(false)
{}
// ----------------------------------------------------------------------------
// OPERATORS : new, delete
//
// Memory management for class scfx_rep.
// ----------------------------------------------------------------------------
union scfx_rep_node
{
char data[sizeof(scfx_rep)];
scfx_rep_node *next;
};
static scfx_rep_node *list = 0;
void *
scfx_rep::operator new(std::size_t size)
{
const int ALLOC_SIZE = 1024;
if (size != sizeof(scfx_rep))
return ::operator new(size);
if (!list) {
list = new scfx_rep_node[ALLOC_SIZE];
for (int i = 0; i < ALLOC_SIZE - 1; i++)
list[i].next = list + i + 1;
list[ALLOC_SIZE - 1].next = 0;
}
scfx_rep *ptr = reinterpret_cast<scfx_rep *>(list->data);
list = list->next;
return ptr;
}
void
scfx_rep::operator delete(void *ptr, std::size_t size)
{
if (size != sizeof(scfx_rep)) {
::operator delete(ptr);
return;
}
scfx_rep_node *node = static_cast<scfx_rep_node *>(ptr);
node->next = list;
list = node;
}
// ----------------------------------------------------------------------------
// METHOD : from_string
//
// Convert from character string to sc_fxrep.
// ----------------------------------------------------------------------------
#define SCFX_FAIL_IF_(cnd) \
{ \
if ((cnd)) { \
m_state = not_a_number; \
m_mant.clear(); /* to avoid Purify UMRs during assignment */ \
return; \
} \
}
void
scfx_rep::from_string(const char *s, int cte_wl)
{
SCFX_FAIL_IF_(s == 0 || *s == 0);
scfx_string s2;
s2 += s;
s2 += '\0';
bool sign_char;
m_sign = scfx_parse_sign(s, sign_char);
sc_numrep numrep = scfx_parse_prefix(s);
int base = 0;
switch (numrep) {
case SC_DEC:
{
base = 10;
if (scfx_is_nan(s)) { // special case: NaN
m_state = not_a_number;
m_mant.clear(); /* to avoid Purify UMRs during assignment */
return;
}
if (scfx_is_inf(s)) { // special case: Infinity
m_state = infinity;
m_mant.clear(); /* to avoid Purify UMRs during assignment */
return;
}
break;
}
case SC_BIN:
case SC_BIN_US:
{
SCFX_FAIL_IF_(sign_char);
base = 2;
break;
}
case SC_BIN_SM:
{
base = 2;
break;
}
case SC_OCT:
case SC_OCT_US:
{
SCFX_FAIL_IF_(sign_char);
base = 8;
break;
}
case SC_OCT_SM:
{
base = 8;
break;
}
case SC_HEX:
case SC_HEX_US:
{
SCFX_FAIL_IF_(sign_char);
base = 16;
break;
}
case SC_HEX_SM:
{
base = 16;
break;
}
case SC_CSD:
{
SCFX_FAIL_IF_(sign_char);
base = 2;
scfx_csd2tc(s2);
s = (const char *)s2 + 4;
numrep = SC_BIN;
break;
}
default:
;
}
//
// find end of mantissa and count the digits and points
//
const char *end = s;
bool based_point = false;
int int_digits = 0;
int frac_digits = 0;
while (*end) {
if (scfx_exp_start(end))
break;
if (*end == '.') {
SCFX_FAIL_IF_(based_point);
based_point = true;
} else {
SCFX_FAIL_IF_(!scfx_is_digit(*end, numrep));
if (based_point)
frac_digits++;
else
int_digits++;
}
++end;
}
SCFX_FAIL_IF_(int_digits == 0 && frac_digits == 0);
// [ exponent ]
int exponent = 0;
if (*end) {
for (const char *e = end + 2; *e; ++e)
SCFX_FAIL_IF_(!scfx_is_digit(*e, SC_DEC));
exponent = std::atoi(end + 1);
}
//
// check if the mantissa is negative
//
bool mant_is_neg = false;
switch (numrep) {
case SC_BIN:
case SC_OCT:
case SC_HEX:
{
const char *p = s;
if (*p == '.')
++p;
mant_is_neg = (scfx_to_digit(* p, numrep) >= (base >> 1));
break;
}
default:
;
}
//
// convert the mantissa
//
switch (base) {
case 2:
{
int bit_offset = exponent % bits_in_word;
int word_offset = exponent / bits_in_word;
int_digits += bit_offset;
frac_digits -= bit_offset;
int words = n_word(int_digits) + n_word(frac_digits);
if (words > size())
resize_to(words);
m_mant.clear();
int j = n_word(frac_digits) * bits_in_word + int_digits - 1;
for (; s < end; s++) {
switch (*s) {
case '1':
set_bin(j);
M5_FALLTHROUGH;
case '0':
j--;
M5_FALLTHROUGH;
case '.':
break;
default:
SCFX_FAIL_IF_(true); // should not happen
}
}
m_wp = n_word(frac_digits) - word_offset;
break;
}
case 8:
{
exponent *= 3;
int_digits *= 3;
frac_digits *= 3;
int bit_offset = exponent % bits_in_word;
int word_offset = exponent / bits_in_word;
int_digits += bit_offset;
frac_digits -= bit_offset;
int words = n_word(int_digits) + n_word(frac_digits);
if (words > size())
resize_to(words);
m_mant.clear();
int j = n_word(frac_digits) * bits_in_word + int_digits - 3;
for (; s < end; s++) {
switch (*s) {
case '7': case '6': case '5': case '4':
case '3': case '2': case '1':
set_oct(j, *s - '0');
M5_FALLTHROUGH;
case '0':
j -= 3;
M5_FALLTHROUGH;
case '.':
break;
default:
SCFX_FAIL_IF_(true); // should not happen
}
}
m_wp = n_word(frac_digits) - word_offset;
break;
}
case 10:
{
word carry, temp;
int length = int_digits + frac_digits;
resize_to(sc_max(min_mant, n_word(4 * length)));
m_mant.clear();
m_msw = m_lsw = 0;
for (; s < end; s++) {
switch (*s) {
case '9': case '8': case '7': case '6': case '5':
case '4': case '3': case '2': case '1': case '0':
multiply_by_ten();
carry = *s - '0';
for (int i = 0; carry && i < m_mant.size(); i++) {
temp = m_mant[i];
temp += carry;
carry = temp < m_mant[i];
m_mant[i] = temp;
}
case '.':
break;
default:
SCFX_FAIL_IF_(true); // should not happen
}
}
m_wp = 0;
find_sw();
int denominator = frac_digits - exponent;
if (denominator) {
scfx_rep frac_num = pow10_fx(denominator);
scfx_rep *temp_num =
div_scfx_rep(const_cast<const scfx_rep &>(*this),
frac_num, cte_wl);
*this = *temp_num;
delete temp_num;
}
break;
}
case 16:
{
exponent *= 4;
int_digits *= 4;
frac_digits *= 4;
int bit_offset = exponent % bits_in_word;
int word_offset = exponent / bits_in_word;
int_digits += bit_offset;
frac_digits -= bit_offset;
int words = n_word(int_digits) + n_word(frac_digits);
if (words > size())
resize_to(words);
m_mant.clear();
int j = n_word(frac_digits) * bits_in_word + int_digits - 4;
for (; s < end; s ++) {
switch (*s) {
case 'f': case 'e': case 'd': case 'c': case 'b': case 'a':
set_hex(j, *s - 'a' + 10);
j -= 4;
break;
case 'F': case 'E': case 'D': case 'C': case 'B': case 'A':
set_hex(j, *s - 'A' + 10);
j -= 4;
break;
case '9': case '8': case '7': case '6': case '5':
case '4': case '3': case '2': case '1':
set_hex(j, *s - '0');
M5_FALLTHROUGH;
case '0':
j -= 4;
M5_FALLTHROUGH;
case '.':
break;
default:
SCFX_FAIL_IF_(true); // should not happen
}
}
m_wp = n_word(frac_digits) - word_offset;
break;
}
}
m_state = normal;
find_sw();
//
// two's complement of mantissa if it is negative
//
if (mant_is_neg) {
m_mant[m_msw] |= ~0U << scfx_find_msb(m_mant[m_msw]);
for (int i = m_msw + 1; i < m_mant.size(); ++i)
m_mant[i] = static_cast<word>(-1);
complement(m_mant, m_mant, m_mant.size());
inc(m_mant);
m_sign *= -1;
find_sw();
}
}
#undef SCFX_FAIL_IF_
// ----------------------------------------------------------------------------
// METHOD : to_double
//
// Convert from scfx_rep to double.
// ----------------------------------------------------------------------------
double
scfx_rep::to_double() const
{
scfx_ieee_double id;
// handle special cases
if (is_nan()) {
id.set_nan();
return id;
}
if (is_inf()) {
id.set_inf();
id.negative(m_sign < 0);
return id;
}
if (is_zero()) {
id = 0.;
id.negative(m_sign < 0);
return id;
}
int msb = scfx_find_msb(m_mant[m_msw]);
int exp = (m_msw - m_wp) * bits_in_word + msb;
if (exp > SCFX_IEEE_DOUBLE_E_MAX) {
id.set_inf();
id.negative(m_sign < 0);
return id;
}
if (exp < SCFX_IEEE_DOUBLE_E_MIN -
static_cast<int>(SCFX_IEEE_DOUBLE_M_SIZE))
{
id = 0.;
return id;
}
int shift = mantissa0_size - msb;
unsigned int m0;
unsigned int m1 = 0;
unsigned int guard = 0;
if (shift == 0) {
m0 = m_mant[m_msw] & ~(1 << mantissa0_size);
if (m_msw > m_lsw) {
m1 = m_mant[m_msw - 1];
if (m_msw - 1 > m_lsw)
guard = m_mant[m_msw - 2] >> (bits_in_word - 1);
}
} else if (shift < 0) {
m0 = (m_mant[m_msw] >> -shift) & ~(1 << mantissa0_size);
m1 = m_mant[m_msw] << (bits_in_word + shift);
if (m_msw > m_lsw) {
m1 |= m_mant[m_msw - 1] >> -shift;
guard = (m_mant[m_msw - 1] >> (-shift - 1)) & 1;
}
} else {
m0 = (m_mant[m_msw] << shift) & ~(1 << mantissa0_size);
if (m_msw > m_lsw) {
m0 |= m_mant[m_msw - 1] >> (bits_in_word - shift);
m1 = m_mant[m_msw - 1] << shift;
if (m_msw - 1 > m_lsw) {
m1 |= m_mant[m_msw - 2] >> (bits_in_word - shift);
guard = (m_mant[m_msw - 2] >> (bits_in_word - shift - 1)) & 1;
}
}
}
if (exp < SCFX_IEEE_DOUBLE_E_MIN) {
m0 |= (1 << mantissa0_size);
int subnormal_shift = SCFX_IEEE_DOUBLE_E_MIN - exp;
if (subnormal_shift < bits_in_word) {
m1 = m1 >> subnormal_shift |
m0 << (bits_in_word - subnormal_shift);
m0 = m0 >> subnormal_shift;
} else {
m1 = m0 >> (subnormal_shift - bits_in_word);
m0 = 0;
}
guard = 0;
exp = SCFX_IEEE_DOUBLE_E_MIN - 1;
}
id.mantissa0(m0);
id.mantissa1(m1);
id.exponent(exp);
id.negative(m_sign < 0);
double result = id;
if (guard != 0)
result += m_sign * scfx_pow2(exp - SCFX_IEEE_DOUBLE_M_SIZE);
return result;
}
// ----------------------------------------------------------------------------
// METHOD : to_uint64
//
// Convert from scfx_rep to uint64.
// Truncates towards 0 _then_ wraps; infinities and NaN go to zero.
// ----------------------------------------------------------------------------
uint64
scfx_rep::to_uint64() const
{
if (!is_normal() || is_zero()) {
return 0;
}
uint64 result = 0;
int shift = 0;
int idx = m_wp;
// Ignore bits off the top; they modulo out.
// Ignore bits off the bottom; we're truncating.
while (shift < 64 && m_msw >= idx && idx >= m_lsw) {
result += static_cast<uint64>(m_mant[idx]) << shift;
shift += bits_in_word;
idx += 1;
}
return m_sign > 0 ? result : -result;
}
// ----------------------------------------------------------------------------
// METHOD : to_string
//
// Convert from scfx_rep to character string.
// ----------------------------------------------------------------------------
void
print_dec(scfx_string &s, const scfx_rep &num, int w_prefix, sc_fmt fmt)
{
if (num.is_neg())
s += '-';
if (w_prefix == 1) {
scfx_print_prefix(s, SC_DEC);
}
if (num.is_zero()) {
s += '0';
return;
}
// split 'num' into its integer and fractional part
scfx_rep int_part = num;
scfx_rep frac_part = num;
int i;
for (i = int_part.m_lsw; i <= int_part.m_msw && i < int_part.m_wp; i++)
int_part.m_mant[i] = 0;
int_part.find_sw();
if (int_part.m_wp < int_part.m_lsw)
int_part.resize_to(int_part.size() - int_part.m_wp, -1);
for (i = frac_part.m_msw;
i >= frac_part.m_lsw && i >= frac_part.m_wp; i--)
frac_part.m_mant[i] = 0;
frac_part.find_sw();
if (frac_part.m_msw == frac_part.size() - 1)
frac_part.resize_to(frac_part.size() + 1, 1);
// print integer part
int int_digits = 0;
int int_zeros = 0;
if (!int_part.is_zero()) {
double int_wl = (int_part.m_msw - int_part.m_wp) * bits_in_word +
scfx_find_msb(int_part.m_mant[int_part.m_msw]) + 1;
int_digits = (int)std::ceil(int_wl * std::log10(2.));
int len = s.length();
s.append(int_digits);
bool zero_digits = (frac_part.is_zero() && fmt != SC_F);
for (i = int_digits + len - 1; i >= len; i--) {
unsigned int remainder = int_part.divide_by_ten();
s[i] = static_cast<char>('0' + remainder);
if (zero_digits) {
if (remainder == 0)
int_zeros++;
else
zero_digits = false;
}
}
// discard trailing zeros from int_part
s.discard(int_zeros);
if (s[len] == '0') {
// int_digits was overestimated by one
s.remove(len);
--int_digits;
}
}
// print fractional part
int frac_digits = 0;
int frac_zeros = 0;
if (!frac_part.is_zero()) {
s += '.';
bool zero_digits = (int_digits == 0 && fmt != SC_F);
double frac_wl = (frac_part.m_wp - frac_part.m_msw) * bits_in_word -
scfx_find_msb(frac_part.m_mant[frac_part.m_msw]) - 1;
frac_zeros = (int)std::floor(frac_wl * std::log10(2.));
scfx_rep temp;
sc_dt::multiply(temp, frac_part, pow10_fx(frac_zeros));
frac_part = temp;
if (frac_part.m_msw == frac_part.size() - 1)
frac_part.resize_to(frac_part.size() + 1, 1);
frac_digits = frac_zeros;
if (!zero_digits) {
for (i = 0; i < frac_zeros; i++)
s += '0';
frac_zeros = 0;
}
while (!frac_part.is_zero()) {
frac_part.multiply_by_ten();
int n = frac_part.m_mant[frac_part.m_msw + 1];
if (zero_digits) {
if (n == 0)
frac_zeros++;
else
zero_digits = false;
}
if (! zero_digits)
s += static_cast<char>('0' + n);
frac_part.m_mant[frac_part.m_msw + 1] = 0;
frac_digits++;
}
}
// print exponent
if (fmt != SC_F) {
if (frac_digits == 0)
scfx_print_exp(s, int_zeros);
else if (int_digits == 0)
scfx_print_exp(s, -frac_zeros);
}
}
void
print_other(scfx_string &s, const scfx_rep &a, sc_numrep numrep, int w_prefix,
sc_fmt fmt, const scfx_params *params)
{
scfx_rep b = a;
sc_numrep numrep2 = numrep;
bool numrep_is_sm = (numrep == SC_BIN_SM ||
numrep == SC_OCT_SM ||
numrep == SC_HEX_SM);
if (numrep_is_sm) {
if (b.is_neg()) {
s += '-';
b = *neg_scfx_rep(a);
}
switch (numrep) {
case SC_BIN_SM:
numrep2 = SC_BIN_US;
break;
case SC_OCT_SM:
numrep2 = SC_OCT_US;
break;
case SC_HEX_SM:
numrep2 = SC_HEX_US;
break;
default:
;
}
}
if (w_prefix != 0) {
scfx_print_prefix(s, numrep);
}
numrep = numrep2;
int msb, lsb;
if (params != 0) {
msb = params->iwl() - 1;
lsb = params->iwl() - params->wl();
if (params->enc() == SC_TC_ &&
(numrep == SC_BIN_US ||
numrep == SC_OCT_US ||
numrep == SC_HEX_US) &&
!numrep_is_sm &&
params->wl() > 1) {
--msb;
} else if (params->enc() == SC_US_ &&
(numrep == SC_BIN ||
numrep == SC_OCT ||
numrep == SC_HEX ||
numrep == SC_CSD)) {
++msb;
}
} else {
if (b.is_zero()) {
msb = 0;
lsb = 0;
} else {
msb = (b.m_msw - b.m_wp) * bits_in_word
+ scfx_find_msb(b.m_mant[ b.m_msw ]) + 1;
while (b.get_bit(msb) == b.get_bit(msb - 1))
--msb;
if (numrep == SC_BIN_US ||
numrep == SC_OCT_US ||
numrep == SC_HEX_US) {
--msb;
}
lsb = (b.m_lsw - b.m_wp) * bits_in_word +
scfx_find_lsb(b.m_mant[b.m_lsw]);
}
}
int step;
switch (numrep) {
case SC_BIN:
case SC_BIN_US:
case SC_CSD:
step = 1;
break;
case SC_OCT:
case SC_OCT_US:
step = 3;
break;
case SC_HEX:
case SC_HEX_US:
step = 4;
break;
default:
SC_REPORT_FATAL("assertion failed", "unexpected sc_numrep");
sc_core::sc_abort();
}
msb = (int)std::ceil(double(msb + 1) / step) * step - 1;
lsb = (int)std::floor(double(lsb) / step) * step;
if (msb < 0) {
s += '.';
if (fmt == SC_F) {
int sign = (b.is_neg()) ? (1 << step) - 1 : 0;
for (int i = (msb + 1) / step; i < 0; i++) {
if (sign < 10)
s += static_cast<char>(sign + '0');
else
s += static_cast<char>(sign + 'a' - 10);
}
}
}
int i = msb;
while (i >= lsb) {
int value = 0;
for (int j = step - 1; j >= 0; --j) {
value += static_cast<int>(b.get_bit(i)) << j;
--i;
}
if (value < 10)
s += static_cast<char>(value + '0');
else
s += static_cast<char>(value + 'a' - 10);
if (i == -1)
s += '.';
}
if (lsb > 0 && fmt == SC_F) {
for (int i = lsb / step; i > 0; i--)
s += '0';
}
if (s[s.length() - 1] == '.')
s.discard(1);
if (fmt != SC_F) {
if (msb < 0)
scfx_print_exp(s, (msb + 1) / step);
else if (lsb > 0)
scfx_print_exp(s, lsb / step);
}
if (numrep == SC_CSD)
scfx_tc2csd(s, w_prefix);
}
const char *
scfx_rep::to_string(sc_numrep numrep, int w_prefix,
sc_fmt fmt, const scfx_params *params) const
{
static scfx_string s;
s.clear();
if (is_nan()) {
scfx_print_nan(s);
} else if (is_inf()) {
scfx_print_inf(s, is_neg());
} else if (is_neg() && !is_zero() &&
(numrep == SC_BIN_US ||
numrep == SC_OCT_US ||
numrep == SC_HEX_US)) {
s += "negative";
} else if (numrep == SC_DEC || numrep == SC_NOBASE) {
sc_dt::print_dec(s, *this, w_prefix, fmt);
} else {
sc_dt::print_other(s, *this, numrep, w_prefix, fmt, params);
}
return s;
}
// ----------------------------------------------------------------------------
// ADD
//
// add two mantissas of the same size
// result has the same size
// returns carry of operation
// ----------------------------------------------------------------------------
static inline int
add_mants(int size, scfx_mant &result, const scfx_mant &a, const scfx_mant &b)
{
unsigned int carry = 0;
int index = 0;
do {
word x = a[index];
word y = b[index];
y += carry;
carry = y < carry;
y += x;
carry += y < x;
result[index] = y;
} while (++index < size);
return (carry ? 1 : 0);
}
static inline int
sub_mants(int size, scfx_mant &result, const scfx_mant &a, const scfx_mant &b)
{
unsigned carry = 0;
int index = 0;
do {
word x = a[index];
word y = b[index];
y += carry;
carry = y < carry;
y = x - y;
carry += y > x;
result[index] = y;
} while (++index < size);
return (carry ? 1 : 0);
}
scfx_rep *
add_scfx_rep(const scfx_rep &lhs, const scfx_rep &rhs, int max_wl)
{
scfx_rep &result = *new scfx_rep;
//
// check for special cases
//
if (lhs.is_nan() || rhs.is_nan() ||
(lhs.is_inf() && rhs.is_inf() && lhs.m_sign != rhs.m_sign)) {
result.set_nan();
return &result;
}
if (lhs.is_inf()) {
result.set_inf(lhs.m_sign);
return &result;
}
if (rhs.is_inf()) {
result.set_inf(rhs.m_sign);
return &result;
}
//
// align operands if needed
//
scfx_mant_ref lhs_mant;
scfx_mant_ref rhs_mant;
int len_mant = lhs.size();
int new_wp = lhs.m_wp;
align(lhs, rhs, new_wp, len_mant, lhs_mant, rhs_mant);
//
// size the result mantissa
//
result.resize_to(len_mant);
result.m_wp = new_wp;
//
// do it
//
if (lhs.m_sign == rhs.m_sign) {
add_mants(len_mant, result.m_mant, lhs_mant, rhs_mant);
result.m_sign = lhs.m_sign;
} else {
int cmp = compare_abs(lhs, rhs);
if (cmp == 1) {
sub_mants(len_mant, result.m_mant, lhs_mant, rhs_mant);
result.m_sign = lhs.m_sign;
} else if (cmp == -1) {
sub_mants(len_mant, result.m_mant, rhs_mant, lhs_mant);
result.m_sign = rhs.m_sign;
} else {
result.m_mant.clear();
result.m_sign = 1;
}
}
result.find_sw();
result.round(max_wl);
return &result;
}
// ----------------------------------------------------------------------------
// SUB
//
// sub two word's of the same size
// result has the same size
// returns carry of operation
// ----------------------------------------------------------------------------
static inline int
sub_with_index(scfx_mant &a, int a_msw, int /*a_lsw*/,
const scfx_mant &b, int b_msw, int b_lsw)
{
unsigned carry = 0;
int size = b_msw - b_lsw;
int a_index = a_msw - size;
int b_index = b_msw - size;
do {
word x = a[a_index];
word y = b[b_index];
y += carry;
carry = y < carry;
y = x - y;
carry += y > x;
a[a_index] = y;
a_index++;
b_index++;
} while (size--);
if (carry) {
// special case: a[a_msw + 1] == 1
a[a_msw + 1] = 0;
}
return (carry ? 1 : 0);
}
scfx_rep *
sub_scfx_rep(const scfx_rep &lhs, const scfx_rep &rhs, int max_wl)
{
scfx_rep &result = *new scfx_rep;
//
// check for special cases
//
if (lhs.is_nan() || rhs.is_nan() ||
(lhs.is_inf() && rhs.is_inf() && lhs.m_sign == rhs.m_sign)) {
result.set_nan();
return &result;
}
if (lhs.is_inf()) {
result.set_inf(lhs.m_sign);
return &result;
}
if (rhs.is_inf()) {
result.set_inf(-1 * rhs.m_sign);
return &result;
}
//
// align operands if needed
//
scfx_mant_ref lhs_mant;
scfx_mant_ref rhs_mant;
int len_mant = lhs.size();
int new_wp = lhs.m_wp;
align(lhs, rhs, new_wp, len_mant, lhs_mant, rhs_mant);
//
// size the result mantissa
//
result.resize_to(len_mant);
result.m_wp = new_wp;
//
// do it
//
if (lhs.m_sign != rhs.m_sign) {
add_mants(len_mant, result.m_mant, lhs_mant, rhs_mant);
result.m_sign = lhs.m_sign;
} else {
int cmp = compare_abs(lhs, rhs);
if (cmp == 1) {
sub_mants(len_mant, result.m_mant, lhs_mant, rhs_mant);
result.m_sign = lhs.m_sign;
} else if (cmp == -1) {
sub_mants(len_mant, result.m_mant, rhs_mant, lhs_mant);
result.m_sign = -rhs.m_sign;
} else {
result.m_mant.clear();
result.m_sign = 1;
}
}
result.find_sw();
result.round(max_wl);
return &result;
}
// ----------------------------------------------------------------------------
// MUL
// ----------------------------------------------------------------------------
union word_short
{
word l;
struct
{
#if defined(SC_BOOST_BIG_ENDIAN)
half_word u;
half_word l;
#elif defined(SC_BOOST_LITTLE_ENDIAN)
half_word l;
half_word u;
#endif
} s;
};
#if defined(SC_BOOST_BIG_ENDIAN)
static const int half_word_incr = -1;
#elif defined(SC_BOOST_LITTLE_ENDIAN)
static const int half_word_incr = 1;
#endif
void
multiply(scfx_rep &result, const scfx_rep &lhs, const scfx_rep &rhs,
int max_wl)
{
//
// check for special cases
//
if (lhs.is_nan() || rhs.is_nan() ||
(lhs.is_inf() && rhs.is_zero()) ||
(lhs.is_zero() && rhs.is_inf())) {
result.set_nan();
return;
}
if (lhs.is_inf() || rhs.is_inf()) {
result.set_inf(lhs.m_sign * rhs.m_sign);
return;
}
if (lhs.is_zero() || rhs.is_zero()) {
result.set_zero(lhs.m_sign * rhs.m_sign);
return;
}
//
// do it
//
int len_lhs = lhs.m_msw - lhs.m_lsw + 1;
int len_rhs = rhs.m_msw - rhs.m_lsw + 1;
int new_size = sc_max(min_mant, len_lhs + len_rhs);
int new_wp = (lhs.m_wp - lhs.m_lsw) + (rhs.m_wp - rhs.m_lsw);
int new_sign = lhs.m_sign * rhs.m_sign;
result.resize_to(new_size);
result.m_mant.clear();
result.m_wp = new_wp;
result.m_sign = new_sign;
result.m_state = scfx_rep::normal;
half_word *s1 = lhs.m_mant.half_addr(lhs.m_lsw);
half_word *s2 = rhs.m_mant.half_addr(rhs.m_lsw);
half_word *t = result.m_mant.half_addr();
len_lhs <<= 1;
len_rhs <<= 1;
int i1, i2;
for (i1 = 0; i1 * half_word_incr < len_lhs; i1 += half_word_incr) {
word_short ls;
ls.l = 0;
half_word v1 = s1[i1];
for (i2 = 0; i2 * half_word_incr < len_rhs; i2 += half_word_incr) {
ls.l += v1 * s2[i2];
ls.s.l = ls.s.u + ((t[i2] += ls.s.l) < ls.s.l);
ls.s.u = 0;
}
t[i2] = ls.s.l;
t += half_word_incr;
}
result.find_sw();
result.round(max_wl);
}
// ----------------------------------------------------------------------------
// DIV
// ----------------------------------------------------------------------------
scfx_rep *
div_scfx_rep(const scfx_rep &lhs, const scfx_rep &rhs, int div_wl)
{
scfx_rep &result = *new scfx_rep;
//
// check for special cases
//
if (lhs.is_nan() || rhs.is_nan() || (lhs.is_inf() && rhs.is_inf()) ||
(lhs.is_zero() && rhs.is_zero())) {
result.set_nan();
return &result;
}
if (lhs.is_inf() || rhs.is_zero()) {
result.set_inf(lhs.m_sign * rhs.m_sign);
return &result;
}
if (lhs.is_zero() || rhs.is_inf()) {
result.set_zero(lhs.m_sign * rhs.m_sign);
return &result;
}
//
// do it
//
// compute one bit more for rounding
div_wl++;
result.resize_to(sc_max(n_word(div_wl) + 1, min_mant));
result.m_mant.clear();
result.m_sign = lhs.m_sign * rhs.m_sign;
int msb_lhs = scfx_find_msb(lhs.m_mant[lhs.m_msw]) +
(lhs.m_msw - lhs.m_wp) * bits_in_word;
int msb_rhs = scfx_find_msb(rhs.m_mant[rhs.m_msw]) +
(rhs.m_msw - rhs.m_wp) * bits_in_word;
int msb_res = msb_lhs - msb_rhs;
int to_shift = -msb_res % bits_in_word;
int result_index;
int c = (msb_res % bits_in_word >= 0) ? 1 : 0;
result_index = (result.size() - c) * bits_in_word + msb_res % bits_in_word;
result.m_wp = (result.size() - c) - msb_res / bits_in_word;
scfx_rep remainder = lhs;
// align msb from remainder to msb from rhs
remainder.lshift(to_shift);
// make sure msw(remainder) < size - 1
if (remainder.m_msw == remainder.size() - 1)
remainder.resize_to(remainder.size() + 1, 1);
// make sure msw(remainder) >= msw(rhs)!
int msw_diff = rhs.m_msw - remainder.m_msw;
if (msw_diff > 0)
remainder.resize_to(remainder.size() + msw_diff, -1);
int counter;
for (counter = div_wl; counter && !remainder.is_zero(); counter--) {
if (compare_msw_ff(rhs, remainder) <= 0) {
result.set_bin(result_index);
sub_with_index(remainder.m_mant, remainder.m_msw, remainder.m_lsw,
rhs.m_mant, rhs.m_msw, rhs.m_lsw);
}
result_index--;
remainder.shift_left(1);
remainder.m_lsw = remainder.find_lsw();
}
// perform convergent rounding, if needed
if (counter == 0) {
int index = result_index + 1 - result.m_wp * bits_in_word;
scfx_index x = result.calc_indices(index);
scfx_index x1 = result.calc_indices(index + 1);
if (result.o_bit_at(x) && result.o_bit_at(x1))
result.q_incr(x);
result.m_r_flag = true;
}
result.find_sw();
return &result;
}
// ----------------------------------------------------------------------------
// destructive shift mantissa to the left
// ----------------------------------------------------------------------------
void
scfx_rep::lshift(int n)
{
if (n == 0)
return;
if (n < 0) {
rshift(-n);
return;
}
if (is_normal()) {
int shift_bits = n % bits_in_word;
int shift_words = n / bits_in_word;
// resize if needed
if (m_msw == size() - 1 &&
scfx_find_msb(m_mant[m_msw]) >= bits_in_word - shift_bits)
resize_to(size() + 1, 1);
// do it
m_wp -= shift_words;
shift_left(shift_bits);
find_sw();
}
}
// ----------------------------------------------------------------------------
// destructive shift mantissa to the right
// ----------------------------------------------------------------------------
void
scfx_rep::rshift(int n)
{
if (n == 0)
return;
if (n < 0) {
lshift(-n);
return;
}
if (is_normal()) {
int shift_bits = n % bits_in_word;
int shift_words = n / bits_in_word;
// resize if needed
if (m_lsw == 0 && scfx_find_lsb(m_mant[m_lsw]) < shift_bits)
resize_to(size() + 1, -1);
// do it
m_wp += shift_words;
shift_right(shift_bits);
find_sw();
}
}
// ----------------------------------------------------------------------------
// FRIEND FUNCTION : compare_abs
//
// Compares the absolute values of two scfx_reps, excluding the special cases.
// ----------------------------------------------------------------------------
int
compare_abs(const scfx_rep &a, const scfx_rep &b)
{
// check for zero
word a_word = a.m_mant[a.m_msw];
word b_word = b.m_mant[b.m_msw];
if (a_word == 0 || b_word == 0) {
if (a_word != 0)
return 1;
if (b_word != 0)
return -1;
return 0;
}
// compare msw index
int a_msw = a.m_msw - a.m_wp;
int b_msw = b.m_msw - b.m_wp;
if (a_msw > b_msw)
return 1;
if (a_msw < b_msw)
return -1;
// compare content
int a_i = a.m_msw;
int b_i = b.m_msw;
while (a_i >= a.m_lsw && b_i >= b.m_lsw) {
a_word = a.m_mant[a_i];
b_word = b.m_mant[b_i];
if (a_word > b_word)
return 1;
if (a_word < b_word)
return -1;
--a_i;
--b_i;
}
bool a_zero = true;
while (a_i >= a.m_lsw) {
a_zero = a_zero && (a.m_mant[a_i] == 0);
--a_i;
}
bool b_zero = true;
while (b_i >= b.m_lsw) {
b_zero = b_zero && (b.m_mant[b_i] == 0);
--b_i;
}
// assertion: a_zero || b_zero
if (!a_zero && b_zero)
return 1;
if (a_zero && !b_zero)
return -1;
return 0;
}
// ----------------------------------------------------------------------------
// FRIEND FUNCTION : cmp_scfx_rep
//
// Compares the values of two scfx_reps, including the special cases.
// ----------------------------------------------------------------------------
int
cmp_scfx_rep(const scfx_rep &a, const scfx_rep &b)
{
// handle special cases
if (a.is_nan() || b.is_nan()) {
return 2;
}
if (a.is_inf() || b.is_inf()) {
if (a.is_inf()) {
if (!a.is_neg()) {
if (b.is_inf() && !b.is_neg()) {
return 0;
} else {
return 1;
}
} else {
if (b.is_inf() && b.is_neg()) {
return 0;
} else {
return -1;
}
}
}
if (b.is_inf()) {
if (!b.is_neg()) {
return -1;
} else {
return 1;
}
}
}
if (a.is_zero() && b.is_zero()) {
return 0;
}
// compare sign
if (a.m_sign != b.m_sign) {
return a.m_sign;
}
return (a.m_sign * compare_abs(a, b));
}
// ----------------------------------------------------------------------------
// PRIVATE METHOD : quantization
//
// Performs destructive quantization.
// ----------------------------------------------------------------------------
void
scfx_rep::quantization(const scfx_params &params, bool &q_flag)
{
scfx_index x = calc_indices(params.iwl() - params.wl());
if (x.wi() < 0)
return;
if (x.wi() >= size())
resize_to(x.wi() + 1, 1);
bool qb = q_bit(x);
bool qz = q_zero(x);
q_flag = (qb || ! qz);
if (q_flag) {
switch (params.q_mode()) {
case SC_TRN: // truncation
{
if (is_neg())
q_incr(x);
break;
}
case SC_RND: // rounding to plus infinity
{
if (!is_neg()) {
if (qb)
q_incr(x);
} else {
if (qb && !qz)
q_incr(x);
}
break;
}
case SC_TRN_ZERO: // truncation to zero
{
break;
}
case SC_RND_INF: // rounding to infinity
{
if (qb)
q_incr(x);
break;
}
case SC_RND_CONV: // convergent rounding
{
if ((qb && !qz) || (qb && qz && q_odd(x)))
q_incr(x);
break;
}
case SC_RND_ZERO: // rounding to zero
{
if (qb && !qz)
q_incr(x);
break;
}
case SC_RND_MIN_INF: // rounding to minus infinity
{
if (!is_neg()) {
if (qb && !qz)
q_incr(x);
} else {
if (qb)
q_incr(x);
}
break;
}
default:
;
}
q_clear(x);
find_sw();
}
}
// ----------------------------------------------------------------------------
// PRIVATE METHOD : overflow
//
// Performs destructive overflow handling.
// ----------------------------------------------------------------------------
void
scfx_rep::overflow(const scfx_params &params, bool &o_flag)
{
scfx_index x = calc_indices(params.iwl() - 1);
if (x.wi() >= size())
resize_to(x.wi() + 1, 1);
if (x.wi() < 0) {
resize_to(size() - x.wi(), -1);
x.wi(0);
}
bool zero_left = o_zero_left(x);
bool bit_at = o_bit_at(x);
bool zero_right = o_zero_right(x);
bool under = false;
bool over = false;
sc_enc enc = params.enc();
if (enc == SC_TC_) {
if (is_neg()) {
if (params.o_mode() == SC_SAT_SYM)
under = (!zero_left || bit_at);
else
under = (!zero_left || (zero_left && bit_at && ! zero_right));
} else {
over = (! zero_left || bit_at);
}
} else {
if (is_neg())
under = (!is_zero());
else
over = (!zero_left);
}
o_flag = (under || over);
if (o_flag) {
scfx_index x2 = calc_indices(params.iwl() - params.wl());
if (x2.wi() < 0) {
resize_to(size() - x2.wi(), -1);
x.wi(x.wi() - x2.wi());
x2.wi(0);
}
switch (params.o_mode()) {
case SC_WRAP: // wrap-around
{
int n_bits = params.n_bits();
if (n_bits == 0) {
// wrap-around all 'wl' bits
toggle_tc();
o_extend(x, enc);
toggle_tc();
} else if (n_bits < params.wl()) {
scfx_index x3 = calc_indices(params.iwl() - 1 - n_bits);
// wrap-around least significant 'wl - n_bits' bits;
// saturate most significant 'n_bits' bits
toggle_tc();
o_set(x, x3, enc, under);
o_extend(x, enc);
toggle_tc();
} else {
// saturate all 'wl' bits
if (under)
o_set_low(x, enc);
else
o_set_high(x, x2, enc);
}
break;
}
case SC_SAT: // saturation
{
if (under)
o_set_low(x, enc);
else
o_set_high(x, x2, enc);
break;
}
case SC_SAT_SYM: // symmetrical saturation
{
if (under) {
if (enc == SC_TC_)
o_set_high(x, x2, SC_TC_, -1);
else
o_set_low(x, SC_US_);
} else {
o_set_high(x, x2, enc);
}
break;
}
case SC_SAT_ZERO: // saturation to zero
{
set_zero();
break;
}
case SC_WRAP_SM: // sign magnitude wrap-around
{
SC_ERROR_IF_(enc == SC_US_,
"SC_WRAP_SM not defined for unsigned numbers");
int n_bits = params.n_bits();
if (n_bits == 0) {
scfx_index x4 = calc_indices(params.iwl());
if (x4.wi() >= size())
resize_to(x4.wi() + 1, 1);
toggle_tc();
if (o_bit_at(x4) != o_bit_at(x))
o_invert(x2);
o_extend(x, SC_TC_);
toggle_tc();
} else if (n_bits == 1) {
toggle_tc();
if (is_neg() != o_bit_at(x))
o_invert(x2);
o_extend(x, SC_TC_);
toggle_tc();
} else if (n_bits < params.wl()) {
scfx_index x3 = calc_indices(params.iwl() - 1 - n_bits);
scfx_index x4 = calc_indices(params.iwl() - n_bits);
// wrap-around least significant 'wl - n_bits' bits;
// saturate most significant 'n_bits' bits
toggle_tc();
if (is_neg() == o_bit_at(x4))
o_invert(x2);
o_set(x, x3, SC_TC_, under);
o_extend(x, SC_TC_);
toggle_tc();
} else {
if (under)
o_set_low(x, SC_TC_);
else
o_set_high(x, x2, SC_TC_);
}
break;
}
default:
;
}
find_sw();
}
}
// ----------------------------------------------------------------------------
// PUBLIC METHOD : cast
//
// Performs a destructive cast operation on a scfx_rep.
// ----------------------------------------------------------------------------
void
scfx_rep::cast(const scfx_params &params, bool &q_flag, bool &o_flag)
{
q_flag = false;
o_flag = false;
// check for special cases
if (is_zero()) {
if (is_neg())
m_sign = 1;
return;
}
// perform casting
quantization(params, q_flag);
overflow(params, o_flag);
// check for special case: -0
if (is_zero() && is_neg())
m_sign = 1;
}
// ----------------------------------------------------------------------------
// make sure, the two mantissas are aligned
// ----------------------------------------------------------------------------
void
align(const scfx_rep &lhs, const scfx_rep &rhs, int &new_wp,
int &len_mant, scfx_mant_ref &lhs_mant, scfx_mant_ref &rhs_mant)
{
bool need_lhs = true;
bool need_rhs = true;
if (lhs.m_wp != rhs.m_wp || lhs.size() != rhs.size()) {
int lower_bound_lhs = lhs.m_lsw - lhs.m_wp;
int upper_bound_lhs = lhs.m_msw - lhs.m_wp;
int lower_bound_rhs = rhs.m_lsw - rhs.m_wp;
int upper_bound_rhs = rhs.m_msw - rhs.m_wp;
int lower_bound = sc_min(lower_bound_lhs, lower_bound_rhs);
int upper_bound = sc_max(upper_bound_lhs, upper_bound_rhs);
new_wp = -lower_bound;
len_mant = sc_max(min_mant, upper_bound - lower_bound + 1);
if (new_wp != lhs.m_wp || len_mant != lhs.size()) {
lhs_mant = lhs.resize(len_mant, new_wp);
need_lhs = false;
}
if (new_wp != rhs.m_wp || len_mant != rhs.size()) {
rhs_mant = rhs.resize(len_mant, new_wp);
need_rhs = false;
}
}
if (need_lhs) {
lhs_mant = lhs.m_mant;
}
if (need_rhs) {
rhs_mant = rhs.m_mant;
}
}
// ----------------------------------------------------------------------------
// compare two mantissas
// ----------------------------------------------------------------------------
int
compare_msw_ff(const scfx_rep &lhs, const scfx_rep &rhs)
{
// special case: rhs.m_mant[rhs.m_msw + 1] == 1
if (rhs.m_msw < rhs.size() - 1 && rhs.m_mant[rhs.m_msw + 1 ] != 0) {
return -1;
}
int lhs_size = lhs.m_msw - lhs.m_lsw + 1;
int rhs_size = rhs.m_msw - rhs.m_lsw + 1;
int size = sc_min(lhs_size, rhs_size);
int lhs_index = lhs.m_msw;
int rhs_index = rhs.m_msw;
int i;
for (i = 0;
i < size && lhs.m_mant[lhs_index] == rhs.m_mant[rhs_index];
i++) {
lhs_index--;
rhs_index--;
}
if (i == size) {
if (lhs_size == rhs_size) {
return 0;
}
if (lhs_size < rhs_size) {
return -1;
} else {
return 1;
}
}
if (lhs.m_mant[lhs_index] < rhs.m_mant[rhs_index]) {
return -1;
} else {
return 1;
}
}
// ----------------------------------------------------------------------------
// divide the mantissa by ten
// ----------------------------------------------------------------------------
unsigned int
scfx_rep::divide_by_ten()
{
#if defined(SC_BOOST_BIG_ENDIAN)
half_word *hw = (half_word *)&m_mant[m_msw];
#elif defined(SC_BOOST_LITTLE_ENDIAN)
half_word *hw = ((half_word *)&m_mant[m_msw]) + 1;
#endif
unsigned int remainder = 0;
word_short ls;
ls.l = 0;
#if defined(SC_BOOST_BIG_ENDIAN)
for (int i = 0, end = (m_msw - m_wp + 1) * 2; i < end; i++) {
#elif defined(SC_BOOST_LITTLE_ENDIAN)
for (int i = 0, end = -(m_msw - m_wp + 1) * 2; i > end; i--) {
#endif
ls.s.u = static_cast<half_word>(remainder);
ls.s.l = hw[i];
remainder = ls.l % 10;
ls.l /= 10;
hw[i] = ls.s.l;
}
return remainder;
}
// ----------------------------------------------------------------------------
// multiply the mantissa by ten
// ----------------------------------------------------------------------------
void
scfx_rep::multiply_by_ten()
{
int size = m_mant.size() + 1;
scfx_mant mant8(size);
scfx_mant mant2(size);
size--;
mant8[size] = (m_mant[size - 1] >> (bits_in_word - 3));
mant2[size] = (m_mant[size - 1] >> (bits_in_word - 1));
while (--size) {
mant8[size] = (m_mant[size] << 3) |
(m_mant[size - 1] >> (bits_in_word - 3));
mant2[size] = (m_mant[size] << 1) |
(m_mant[size - 1] >> (bits_in_word - 1));
}
mant8[0] = (m_mant[0] << 3);
mant2[0] = (m_mant[0] << 1);
add_mants(m_mant.size(), m_mant, mant8, mant2);
}
// ----------------------------------------------------------------------------
// normalize
// ----------------------------------------------------------------------------
void
scfx_rep::normalize(int exponent)
{
int shift = exponent % bits_in_word;
if (shift < 0) {
shift += bits_in_word;
}
if (shift) {
shift_left(shift);
}
find_sw();
m_wp = (shift - exponent) / bits_in_word;
}
// ----------------------------------------------------------------------------
// return a new mantissa that is aligned and resized
// ----------------------------------------------------------------------------
scfx_mant *
scfx_rep::resize(int new_size, int new_wp) const
{
scfx_mant *result = new scfx_mant(new_size);
result->clear();
int shift = new_wp - m_wp;
for (int j = m_lsw; j <= m_msw; j++) {
(*result)[j + shift] = m_mant[j];
}
return result;
}
// ----------------------------------------------------------------------------
// set a single bit
// ----------------------------------------------------------------------------
void
scfx_rep::set_bin(int i)
{
m_mant[i >> 5] |= 1 << (i & 31);
}
// ----------------------------------------------------------------------------
// set three bits
// ----------------------------------------------------------------------------
void
scfx_rep::set_oct(int i, int n)
{
if (n & 1) {
m_mant[i >> 5] |= 1 << (i & 31);
}
i++;
if (n & 2) {
m_mant[i >> 5] |= 1 << (i & 31);
}
i++;
if (n & 4) {
m_mant[i >> 5] |= 1 << (i & 31);
}
}
// ----------------------------------------------------------------------------
// set four bits
// ----------------------------------------------------------------------------
void
scfx_rep::set_hex(int i, int n)
{
if (n & 1) {
m_mant[i >> 5] |= 1 << (i & 31);
}
i++;
if (n & 2) {
m_mant[i >> 5] |= 1 << (i & 31);
}
i++;
if (n & 4) {
m_mant[i >> 5] |= 1 << (i & 31);
}
i++;
if (n & 8) {
m_mant[i >> 5] |= 1 << (i & 31);
}
}
// ----------------------------------------------------------------------------
// PRIVATE METHOD : shift_left
//
// Shifts a scfx_rep to the left by a MAXIMUM of bits_in_word - 1 bits.
// ----------------------------------------------------------------------------
void
scfx_rep::shift_left(int n)
{
if (n != 0) {
int shift_left = n;
int shift_right = bits_in_word - n;
SC_ASSERT_(!(m_mant[size() - 1] >> shift_right),
"shift_left overflow");
for (int i = size() - 1; i > 0; i--) {
m_mant[i] = (m_mant[i] << shift_left) |
(m_mant[i - 1] >> shift_right);
}
m_mant[0] <<= shift_left;
}
}
// ----------------------------------------------------------------------------
// PRIVATE METHOD : shift_right
//
// Shifts a scfx_rep to the right by a MAXIMUM of bits_in_word - 1 bits.
// ----------------------------------------------------------------------------
void
scfx_rep::shift_right(int n)
{
if (n != 0) {
int shift_left = bits_in_word - n;
int shift_right = n;
SC_ASSERT_(!(m_mant[0] << shift_left), "shift_right overflow");
for (int i = 0; i < size() - 1; i++) {
m_mant[i] = (m_mant[i] >> shift_right) |
(m_mant[i + 1] << shift_left);
}
m_mant[size() - 1] >>= shift_right;
}
}
// ----------------------------------------------------------------------------
// METHOD : get_bit
//
// Tests a bit, in two's complement.
// ----------------------------------------------------------------------------
bool
scfx_rep::get_bit(int i) const
{
if (!is_normal())
return false;
scfx_index x = calc_indices(i);
if (x.wi() >= size())
return is_neg();
if (x.wi() < 0)
return false;
const_cast<scfx_rep*>(this)->toggle_tc();
bool result = (m_mant[x.wi()] & (1 << x.bi())) != 0;
const_cast<scfx_rep *>(this)->toggle_tc();
return result;
}
// ----------------------------------------------------------------------------
// METHOD : set
//
// Sets a bit, in two's complement, between iwl-1 and -fwl.
// ----------------------------------------------------------------------------
bool
scfx_rep::set(int i, const scfx_params &params)
{
if (!is_normal())
return false;
scfx_index x = calc_indices(i);
if (x.wi() >= size()) {
if (is_neg())
return true;
else
resize_to(x.wi() + 1, 1);
} else if (x.wi() < 0) {
resize_to(size() - x.wi(), -1);
x.wi(0);
}
toggle_tc();
m_mant[x.wi()] |= 1 << x.bi();
if (i == params.iwl() - 1)
o_extend(x, params.enc()); // sign extension
toggle_tc();
find_sw();
return true;
}
// ----------------------------------------------------------------------------
// METHOD : clear
//
// Clears a bit, in two's complement, between iwl-1 and -fwl.
// ----------------------------------------------------------------------------
bool
scfx_rep::clear(int i, const scfx_params &params)
{
if (!is_normal())
return false;
scfx_index x = calc_indices(i);
if (x.wi() >= size()) {
if (!is_neg())
return true;
else
resize_to(x.wi() + 1, 1);
} else if (x.wi() < 0) {
return true;
}
toggle_tc();
m_mant[x.wi()] &= ~(1 << x.bi());
if (i == params.iwl() - 1)
o_extend(x, params.enc()); // sign extension
toggle_tc();
find_sw();
return true;
}
// ----------------------------------------------------------------------------
// METHOD : get_slice
// ----------------------------------------------------------------------------
bool
scfx_rep::get_slice(int i, int j, const scfx_params &, sc_bv_base &bv) const
{
if (is_nan() || is_inf())
return false;
// get the bits
int l = j;
for (int k = 0; k < bv.length(); ++k) {
bv[k] = get_bit(l);
if (i >= j)
++l;
else
--l;
}
return true;
}
bool
scfx_rep::set_slice(int i, int j, const scfx_params &params,
const sc_bv_base &bv)
{
if (is_nan() || is_inf())
return false;
// set the bits
int l = j;
for (int k = 0; k < bv.length(); ++k) {
if (bv[k].to_bool())
set(l, params);
else
clear(l, params);
if (i >= j)
++l;
else
--l;
}
return true;
}
// ----------------------------------------------------------------------------
// METHOD : print
// ----------------------------------------------------------------------------
void
scfx_rep::print(::std::ostream &os) const
{
os << to_string(SC_DEC, -1, SC_E);
}
// ----------------------------------------------------------------------------
// METHOD : dump
// ----------------------------------------------------------------------------
void
scfx_rep::dump(::std::ostream &os) const
{
os << "scfx_rep" << ::std::endl;
os << "(" << ::std::endl;
os << "mant =" << ::std::endl;
for (int i = size() - 1; i >= 0; i--) {
char buf[BUFSIZ];
std::sprintf(buf, " %d: %10u (%8x)", i,
(int)m_mant[i], (int)m_mant[i]);
os << buf << ::std::endl;
}
os << "wp = " << m_wp << ::std::endl;
os << "sign = " << m_sign << ::std::endl;
os << "state = ";
switch (m_state) {
case normal:
os << "normal";
break;
case infinity:
os << "infinity";
break;
case not_a_number:
os << "not_a_number";
break;
default:
os << "unknown";
}
os << ::std::endl;
os << "msw = " << m_msw << ::std::endl;
os << "lsw = " << m_lsw << ::std::endl;
os << ")" << ::std::endl;
}
// ----------------------------------------------------------------------------
// METHOD : get_type
// ----------------------------------------------------------------------------
void
scfx_rep::get_type(int &wl, int &iwl, sc_enc &enc) const
{
if (is_nan() || is_inf()) {
wl = 0;
iwl = 0;
enc = SC_TC_;
return;
}
if (is_zero()) {
wl = 1;
iwl = 1;
enc = SC_US_;
return;
}
int msb = (m_msw - m_wp) * bits_in_word +
scfx_find_msb(m_mant[ m_msw ]) + 1;
while (get_bit(msb) == get_bit(msb - 1)) {
--msb;
}
int lsb = (m_lsw - m_wp) * bits_in_word +
scfx_find_lsb(m_mant[m_lsw]);
if (is_neg()) {
wl = msb - lsb + 1;
iwl = msb + 1;
enc = SC_TC_;
} else {
wl = msb - lsb;
iwl = msb;
enc = SC_US_;
}
}
// ----------------------------------------------------------------------------
// PRIVATE METHOD : round
//
// Performs convergent rounding (rounding to even) as in floating-point.
// ----------------------------------------------------------------------------
void
scfx_rep::round(int wl)
{
// check for special cases
if (is_nan() || is_inf() || is_zero())
return;
// estimate effective wordlength and compare
int wl_effective;
wl_effective = (m_msw - m_lsw + 1) * bits_in_word;
if (wl_effective <= wl)
return;
// calculate effective wordlength and compare
int msb = scfx_find_msb(m_mant[m_msw]);
int lsb = scfx_find_lsb(m_mant[m_lsw]);
wl_effective = (m_msw * bits_in_word + msb) -
(m_lsw * bits_in_word + lsb) + 1;
if (wl_effective <= wl)
return;
// perform rounding
int wi = m_msw - (wl - 1) / bits_in_word;
int bi = msb - (wl - 1) % bits_in_word;
if (bi < 0) {
--wi;
bi += bits_in_word;
}
scfx_index x(wi, bi);
if ((q_bit(x) && ! q_zero(x)) || (q_bit(x) && q_zero(x) && q_odd(x))) {
q_incr(x);
}
q_clear(x);
find_sw();
m_r_flag = true;
}
} // namespace sc_dt