mirror of
https://git.FreeBSD.org/src.git
synced 2024-12-24 11:29:10 +00:00
4417 lines
92 KiB
C
4417 lines
92 KiB
C
/* real.c - software floating point emulation.
|
||
Copyright (C) 1993, 1994, 1995, 1996, 1997, 1998,
|
||
1999, 2000, 2002, 2003 Free Software Foundation, Inc.
|
||
Contributed by Stephen L. Moshier (moshier@world.std.com).
|
||
Re-written by Richard Henderson <rth@redhat.com>
|
||
|
||
This file is part of GCC.
|
||
|
||
GCC 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.
|
||
|
||
GCC 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 GCC; see the file COPYING. If not, write to the Free
|
||
Software Foundation, 59 Temple Place - Suite 330, Boston, MA
|
||
02111-1307, USA. */
|
||
|
||
#include "config.h"
|
||
#include "system.h"
|
||
#include "tree.h"
|
||
#include "toplev.h"
|
||
#include "real.h"
|
||
#include "tm_p.h"
|
||
|
||
/* The floating point model used internally is not exactly IEEE 754
|
||
compliant, and close to the description in the ISO C standard,
|
||
section 5.2.4.2.2 Characteristics of floating types.
|
||
|
||
Specifically
|
||
|
||
x = s * b^e * \sum_{k=1}^p f_k * b^{-k}
|
||
|
||
where
|
||
s = sign (+- 1)
|
||
b = base or radix, here always 2
|
||
e = exponent
|
||
p = precision (the number of base-b digits in the significand)
|
||
f_k = the digits of the significand.
|
||
|
||
We differ from typical IEEE 754 encodings in that the entire
|
||
significand is fractional. Normalized significands are in the
|
||
range [0.5, 1.0).
|
||
|
||
A requirement of the model is that P be larger than than the
|
||
largest supported target floating-point type by at least 2 bits.
|
||
This gives us proper rounding when we truncate to the target type.
|
||
In addition, E must be large enough to hold the smallest supported
|
||
denormal number in a normalized form.
|
||
|
||
Both of these requirements are easily satisfied. The largest target
|
||
significand is 113 bits; we store at least 160. The smallest
|
||
denormal number fits in 17 exponent bits; we store 29.
|
||
|
||
Note that the decimal string conversion routines are sensitive to
|
||
rounding error. Since the raw arithmetic routines do not themselves
|
||
have guard digits or rounding, the computation of 10**exp can
|
||
accumulate more than a few digits of error. The previous incarnation
|
||
of real.c successfully used a 144 bit fraction; given the current
|
||
layout of REAL_VALUE_TYPE we're forced to expand to at least 160 bits.
|
||
|
||
Target floating point models that use base 16 instead of base 2
|
||
(i.e. IBM 370), are handled during round_for_format, in which we
|
||
canonicalize the exponent to be a multiple of 4 (log2(16)), and
|
||
adjust the significand to match. */
|
||
|
||
|
||
/* Used to classify two numbers simultaneously. */
|
||
#define CLASS2(A, B) ((A) << 2 | (B))
|
||
|
||
#if HOST_BITS_PER_LONG != 64 && HOST_BITS_PER_LONG != 32
|
||
#error "Some constant folding done by hand to avoid shift count warnings"
|
||
#endif
|
||
|
||
static void get_zero PARAMS ((REAL_VALUE_TYPE *, int));
|
||
static void get_canonical_qnan PARAMS ((REAL_VALUE_TYPE *, int));
|
||
static void get_canonical_snan PARAMS ((REAL_VALUE_TYPE *, int));
|
||
static void get_inf PARAMS ((REAL_VALUE_TYPE *, int));
|
||
static bool sticky_rshift_significand PARAMS ((REAL_VALUE_TYPE *,
|
||
const REAL_VALUE_TYPE *,
|
||
unsigned int));
|
||
static void rshift_significand PARAMS ((REAL_VALUE_TYPE *,
|
||
const REAL_VALUE_TYPE *,
|
||
unsigned int));
|
||
static void lshift_significand PARAMS ((REAL_VALUE_TYPE *,
|
||
const REAL_VALUE_TYPE *,
|
||
unsigned int));
|
||
static void lshift_significand_1 PARAMS ((REAL_VALUE_TYPE *,
|
||
const REAL_VALUE_TYPE *));
|
||
static bool add_significands PARAMS ((REAL_VALUE_TYPE *r,
|
||
const REAL_VALUE_TYPE *,
|
||
const REAL_VALUE_TYPE *));
|
||
static bool sub_significands PARAMS ((REAL_VALUE_TYPE *,
|
||
const REAL_VALUE_TYPE *,
|
||
const REAL_VALUE_TYPE *, int));
|
||
static void neg_significand PARAMS ((REAL_VALUE_TYPE *,
|
||
const REAL_VALUE_TYPE *));
|
||
static int cmp_significands PARAMS ((const REAL_VALUE_TYPE *,
|
||
const REAL_VALUE_TYPE *));
|
||
static int cmp_significand_0 PARAMS ((const REAL_VALUE_TYPE *));
|
||
static void set_significand_bit PARAMS ((REAL_VALUE_TYPE *, unsigned int));
|
||
static void clear_significand_bit PARAMS ((REAL_VALUE_TYPE *, unsigned int));
|
||
static bool test_significand_bit PARAMS ((REAL_VALUE_TYPE *, unsigned int));
|
||
static void clear_significand_below PARAMS ((REAL_VALUE_TYPE *,
|
||
unsigned int));
|
||
static bool div_significands PARAMS ((REAL_VALUE_TYPE *,
|
||
const REAL_VALUE_TYPE *,
|
||
const REAL_VALUE_TYPE *));
|
||
static void normalize PARAMS ((REAL_VALUE_TYPE *));
|
||
|
||
static void do_add PARAMS ((REAL_VALUE_TYPE *, const REAL_VALUE_TYPE *,
|
||
const REAL_VALUE_TYPE *, int));
|
||
static void do_multiply PARAMS ((REAL_VALUE_TYPE *,
|
||
const REAL_VALUE_TYPE *,
|
||
const REAL_VALUE_TYPE *));
|
||
static void do_divide PARAMS ((REAL_VALUE_TYPE *, const REAL_VALUE_TYPE *,
|
||
const REAL_VALUE_TYPE *));
|
||
static int do_compare PARAMS ((const REAL_VALUE_TYPE *,
|
||
const REAL_VALUE_TYPE *, int));
|
||
static void do_fix_trunc PARAMS ((REAL_VALUE_TYPE *, const REAL_VALUE_TYPE *));
|
||
|
||
static unsigned long rtd_divmod PARAMS ((REAL_VALUE_TYPE *,
|
||
REAL_VALUE_TYPE *));
|
||
|
||
static const REAL_VALUE_TYPE * ten_to_ptwo PARAMS ((int));
|
||
static const REAL_VALUE_TYPE * ten_to_mptwo PARAMS ((int));
|
||
static const REAL_VALUE_TYPE * real_digit PARAMS ((int));
|
||
static void times_pten PARAMS ((REAL_VALUE_TYPE *, int));
|
||
|
||
static void round_for_format PARAMS ((const struct real_format *,
|
||
REAL_VALUE_TYPE *));
|
||
|
||
/* Initialize R with a positive zero. */
|
||
|
||
static inline void
|
||
get_zero (r, sign)
|
||
REAL_VALUE_TYPE *r;
|
||
int sign;
|
||
{
|
||
memset (r, 0, sizeof (*r));
|
||
r->sign = sign;
|
||
}
|
||
|
||
/* Initialize R with the canonical quiet NaN. */
|
||
|
||
static inline void
|
||
get_canonical_qnan (r, sign)
|
||
REAL_VALUE_TYPE *r;
|
||
int sign;
|
||
{
|
||
memset (r, 0, sizeof (*r));
|
||
r->class = rvc_nan;
|
||
r->sign = sign;
|
||
r->sig[SIGSZ-1] = SIG_MSB >> 1;
|
||
}
|
||
|
||
static inline void
|
||
get_canonical_snan (r, sign)
|
||
REAL_VALUE_TYPE *r;
|
||
int sign;
|
||
{
|
||
memset (r, 0, sizeof (*r));
|
||
r->class = rvc_nan;
|
||
r->sign = sign;
|
||
r->sig[SIGSZ-1] = SIG_MSB >> 2;
|
||
}
|
||
|
||
static inline void
|
||
get_inf (r, sign)
|
||
REAL_VALUE_TYPE *r;
|
||
int sign;
|
||
{
|
||
memset (r, 0, sizeof (*r));
|
||
r->class = rvc_inf;
|
||
r->sign = sign;
|
||
}
|
||
|
||
|
||
/* Right-shift the significand of A by N bits; put the result in the
|
||
significand of R. If any one bits are shifted out, return true. */
|
||
|
||
static bool
|
||
sticky_rshift_significand (r, a, n)
|
||
REAL_VALUE_TYPE *r;
|
||
const REAL_VALUE_TYPE *a;
|
||
unsigned int n;
|
||
{
|
||
unsigned long sticky = 0;
|
||
unsigned int i, ofs = 0;
|
||
|
||
if (n >= HOST_BITS_PER_LONG)
|
||
{
|
||
for (i = 0, ofs = n / HOST_BITS_PER_LONG; i < ofs; ++i)
|
||
sticky |= a->sig[i];
|
||
n &= HOST_BITS_PER_LONG - 1;
|
||
}
|
||
|
||
if (n != 0)
|
||
{
|
||
sticky |= a->sig[ofs] & (((unsigned long)1 << n) - 1);
|
||
for (i = 0; i < SIGSZ; ++i)
|
||
{
|
||
r->sig[i]
|
||
= (((ofs + i >= SIGSZ ? 0 : a->sig[ofs + i]) >> n)
|
||
| ((ofs + i + 1 >= SIGSZ ? 0 : a->sig[ofs + i + 1])
|
||
<< (HOST_BITS_PER_LONG - n)));
|
||
}
|
||
}
|
||
else
|
||
{
|
||
for (i = 0; ofs + i < SIGSZ; ++i)
|
||
r->sig[i] = a->sig[ofs + i];
|
||
for (; i < SIGSZ; ++i)
|
||
r->sig[i] = 0;
|
||
}
|
||
|
||
return sticky != 0;
|
||
}
|
||
|
||
/* Right-shift the significand of A by N bits; put the result in the
|
||
significand of R. */
|
||
|
||
static void
|
||
rshift_significand (r, a, n)
|
||
REAL_VALUE_TYPE *r;
|
||
const REAL_VALUE_TYPE *a;
|
||
unsigned int n;
|
||
{
|
||
unsigned int i, ofs = n / HOST_BITS_PER_LONG;
|
||
|
||
n &= HOST_BITS_PER_LONG - 1;
|
||
if (n != 0)
|
||
{
|
||
for (i = 0; i < SIGSZ; ++i)
|
||
{
|
||
r->sig[i]
|
||
= (((ofs + i >= SIGSZ ? 0 : a->sig[ofs + i]) >> n)
|
||
| ((ofs + i + 1 >= SIGSZ ? 0 : a->sig[ofs + i + 1])
|
||
<< (HOST_BITS_PER_LONG - n)));
|
||
}
|
||
}
|
||
else
|
||
{
|
||
for (i = 0; ofs + i < SIGSZ; ++i)
|
||
r->sig[i] = a->sig[ofs + i];
|
||
for (; i < SIGSZ; ++i)
|
||
r->sig[i] = 0;
|
||
}
|
||
}
|
||
|
||
/* Left-shift the significand of A by N bits; put the result in the
|
||
significand of R. */
|
||
|
||
static void
|
||
lshift_significand (r, a, n)
|
||
REAL_VALUE_TYPE *r;
|
||
const REAL_VALUE_TYPE *a;
|
||
unsigned int n;
|
||
{
|
||
unsigned int i, ofs = n / HOST_BITS_PER_LONG;
|
||
|
||
n &= HOST_BITS_PER_LONG - 1;
|
||
if (n == 0)
|
||
{
|
||
for (i = 0; ofs + i < SIGSZ; ++i)
|
||
r->sig[SIGSZ-1-i] = a->sig[SIGSZ-1-i-ofs];
|
||
for (; i < SIGSZ; ++i)
|
||
r->sig[SIGSZ-1-i] = 0;
|
||
}
|
||
else
|
||
for (i = 0; i < SIGSZ; ++i)
|
||
{
|
||
r->sig[SIGSZ-1-i]
|
||
= (((ofs + i >= SIGSZ ? 0 : a->sig[SIGSZ-1-i-ofs]) << n)
|
||
| ((ofs + i + 1 >= SIGSZ ? 0 : a->sig[SIGSZ-1-i-ofs-1])
|
||
>> (HOST_BITS_PER_LONG - n)));
|
||
}
|
||
}
|
||
|
||
/* Likewise, but N is specialized to 1. */
|
||
|
||
static inline void
|
||
lshift_significand_1 (r, a)
|
||
REAL_VALUE_TYPE *r;
|
||
const REAL_VALUE_TYPE *a;
|
||
{
|
||
unsigned int i;
|
||
|
||
for (i = SIGSZ - 1; i > 0; --i)
|
||
r->sig[i] = (a->sig[i] << 1) | (a->sig[i-1] >> (HOST_BITS_PER_LONG - 1));
|
||
r->sig[0] = a->sig[0] << 1;
|
||
}
|
||
|
||
/* Add the significands of A and B, placing the result in R. Return
|
||
true if there was carry out of the most significant word. */
|
||
|
||
static inline bool
|
||
add_significands (r, a, b)
|
||
REAL_VALUE_TYPE *r;
|
||
const REAL_VALUE_TYPE *a, *b;
|
||
{
|
||
bool carry = false;
|
||
int i;
|
||
|
||
for (i = 0; i < SIGSZ; ++i)
|
||
{
|
||
unsigned long ai = a->sig[i];
|
||
unsigned long ri = ai + b->sig[i];
|
||
|
||
if (carry)
|
||
{
|
||
carry = ri < ai;
|
||
carry |= ++ri == 0;
|
||
}
|
||
else
|
||
carry = ri < ai;
|
||
|
||
r->sig[i] = ri;
|
||
}
|
||
|
||
return carry;
|
||
}
|
||
|
||
/* Subtract the significands of A and B, placing the result in R. CARRY is
|
||
true if there's a borrow incoming to the least significant word.
|
||
Return true if there was borrow out of the most significant word. */
|
||
|
||
static inline bool
|
||
sub_significands (r, a, b, carry)
|
||
REAL_VALUE_TYPE *r;
|
||
const REAL_VALUE_TYPE *a, *b;
|
||
int carry;
|
||
{
|
||
int i;
|
||
|
||
for (i = 0; i < SIGSZ; ++i)
|
||
{
|
||
unsigned long ai = a->sig[i];
|
||
unsigned long ri = ai - b->sig[i];
|
||
|
||
if (carry)
|
||
{
|
||
carry = ri > ai;
|
||
carry |= ~--ri == 0;
|
||
}
|
||
else
|
||
carry = ri > ai;
|
||
|
||
r->sig[i] = ri;
|
||
}
|
||
|
||
return carry;
|
||
}
|
||
|
||
/* Negate the significand A, placing the result in R. */
|
||
|
||
static inline void
|
||
neg_significand (r, a)
|
||
REAL_VALUE_TYPE *r;
|
||
const REAL_VALUE_TYPE *a;
|
||
{
|
||
bool carry = true;
|
||
int i;
|
||
|
||
for (i = 0; i < SIGSZ; ++i)
|
||
{
|
||
unsigned long ri, ai = a->sig[i];
|
||
|
||
if (carry)
|
||
{
|
||
if (ai)
|
||
{
|
||
ri = -ai;
|
||
carry = false;
|
||
}
|
||
else
|
||
ri = ai;
|
||
}
|
||
else
|
||
ri = ~ai;
|
||
|
||
r->sig[i] = ri;
|
||
}
|
||
}
|
||
|
||
/* Compare significands. Return tri-state vs zero. */
|
||
|
||
static inline int
|
||
cmp_significands (a, b)
|
||
const REAL_VALUE_TYPE *a, *b;
|
||
{
|
||
int i;
|
||
|
||
for (i = SIGSZ - 1; i >= 0; --i)
|
||
{
|
||
unsigned long ai = a->sig[i];
|
||
unsigned long bi = b->sig[i];
|
||
|
||
if (ai > bi)
|
||
return 1;
|
||
if (ai < bi)
|
||
return -1;
|
||
}
|
||
|
||
return 0;
|
||
}
|
||
|
||
/* Return true if A is nonzero. */
|
||
|
||
static inline int
|
||
cmp_significand_0 (a)
|
||
const REAL_VALUE_TYPE *a;
|
||
{
|
||
int i;
|
||
|
||
for (i = SIGSZ - 1; i >= 0; --i)
|
||
if (a->sig[i])
|
||
return 1;
|
||
|
||
return 0;
|
||
}
|
||
|
||
/* Set bit N of the significand of R. */
|
||
|
||
static inline void
|
||
set_significand_bit (r, n)
|
||
REAL_VALUE_TYPE *r;
|
||
unsigned int n;
|
||
{
|
||
r->sig[n / HOST_BITS_PER_LONG]
|
||
|= (unsigned long)1 << (n % HOST_BITS_PER_LONG);
|
||
}
|
||
|
||
/* Clear bit N of the significand of R. */
|
||
|
||
static inline void
|
||
clear_significand_bit (r, n)
|
||
REAL_VALUE_TYPE *r;
|
||
unsigned int n;
|
||
{
|
||
r->sig[n / HOST_BITS_PER_LONG]
|
||
&= ~((unsigned long)1 << (n % HOST_BITS_PER_LONG));
|
||
}
|
||
|
||
/* Test bit N of the significand of R. */
|
||
|
||
static inline bool
|
||
test_significand_bit (r, n)
|
||
REAL_VALUE_TYPE *r;
|
||
unsigned int n;
|
||
{
|
||
/* ??? Compiler bug here if we return this expression directly.
|
||
The conversion to bool strips the "&1" and we wind up testing
|
||
e.g. 2 != 0 -> true. Seen in gcc version 3.2 20020520. */
|
||
int t = (r->sig[n / HOST_BITS_PER_LONG] >> (n % HOST_BITS_PER_LONG)) & 1;
|
||
return t;
|
||
}
|
||
|
||
/* Clear bits 0..N-1 of the significand of R. */
|
||
|
||
static void
|
||
clear_significand_below (r, n)
|
||
REAL_VALUE_TYPE *r;
|
||
unsigned int n;
|
||
{
|
||
int i, w = n / HOST_BITS_PER_LONG;
|
||
|
||
for (i = 0; i < w; ++i)
|
||
r->sig[i] = 0;
|
||
|
||
r->sig[w] &= ~(((unsigned long)1 << (n % HOST_BITS_PER_LONG)) - 1);
|
||
}
|
||
|
||
/* Divide the significands of A and B, placing the result in R. Return
|
||
true if the division was inexact. */
|
||
|
||
static inline bool
|
||
div_significands (r, a, b)
|
||
REAL_VALUE_TYPE *r;
|
||
const REAL_VALUE_TYPE *a, *b;
|
||
{
|
||
REAL_VALUE_TYPE u;
|
||
int i, bit = SIGNIFICAND_BITS - 1;
|
||
unsigned long msb, inexact;
|
||
|
||
u = *a;
|
||
memset (r->sig, 0, sizeof (r->sig));
|
||
|
||
msb = 0;
|
||
goto start;
|
||
do
|
||
{
|
||
msb = u.sig[SIGSZ-1] & SIG_MSB;
|
||
lshift_significand_1 (&u, &u);
|
||
start:
|
||
if (msb || cmp_significands (&u, b) >= 0)
|
||
{
|
||
sub_significands (&u, &u, b, 0);
|
||
set_significand_bit (r, bit);
|
||
}
|
||
}
|
||
while (--bit >= 0);
|
||
|
||
for (i = 0, inexact = 0; i < SIGSZ; i++)
|
||
inexact |= u.sig[i];
|
||
|
||
return inexact != 0;
|
||
}
|
||
|
||
/* Adjust the exponent and significand of R such that the most
|
||
significant bit is set. We underflow to zero and overflow to
|
||
infinity here, without denormals. (The intermediate representation
|
||
exponent is large enough to handle target denormals normalized.) */
|
||
|
||
static void
|
||
normalize (r)
|
||
REAL_VALUE_TYPE *r;
|
||
{
|
||
int shift = 0, exp;
|
||
int i, j;
|
||
|
||
/* Find the first word that is nonzero. */
|
||
for (i = SIGSZ - 1; i >= 0; i--)
|
||
if (r->sig[i] == 0)
|
||
shift += HOST_BITS_PER_LONG;
|
||
else
|
||
break;
|
||
|
||
/* Zero significand flushes to zero. */
|
||
if (i < 0)
|
||
{
|
||
r->class = rvc_zero;
|
||
r->exp = 0;
|
||
return;
|
||
}
|
||
|
||
/* Find the first bit that is nonzero. */
|
||
for (j = 0; ; j++)
|
||
if (r->sig[i] & ((unsigned long)1 << (HOST_BITS_PER_LONG - 1 - j)))
|
||
break;
|
||
shift += j;
|
||
|
||
if (shift > 0)
|
||
{
|
||
exp = r->exp - shift;
|
||
if (exp > MAX_EXP)
|
||
get_inf (r, r->sign);
|
||
else if (exp < -MAX_EXP)
|
||
get_zero (r, r->sign);
|
||
else
|
||
{
|
||
r->exp = exp;
|
||
lshift_significand (r, r, shift);
|
||
}
|
||
}
|
||
}
|
||
|
||
/* Return R = A + (SUBTRACT_P ? -B : B). */
|
||
|
||
static void
|
||
do_add (r, a, b, subtract_p)
|
||
REAL_VALUE_TYPE *r;
|
||
const REAL_VALUE_TYPE *a, *b;
|
||
int subtract_p;
|
||
{
|
||
int dexp, sign, exp;
|
||
REAL_VALUE_TYPE t;
|
||
bool inexact = false;
|
||
|
||
/* Determine if we need to add or subtract. */
|
||
sign = a->sign;
|
||
subtract_p = (sign ^ b->sign) ^ subtract_p;
|
||
|
||
switch (CLASS2 (a->class, b->class))
|
||
{
|
||
case CLASS2 (rvc_zero, rvc_zero):
|
||
/* -0 + -0 = -0, -0 - +0 = -0; all other cases yield +0. */
|
||
get_zero (r, sign & !subtract_p);
|
||
return;
|
||
|
||
case CLASS2 (rvc_zero, rvc_normal):
|
||
case CLASS2 (rvc_zero, rvc_inf):
|
||
case CLASS2 (rvc_zero, rvc_nan):
|
||
/* 0 + ANY = ANY. */
|
||
case CLASS2 (rvc_normal, rvc_nan):
|
||
case CLASS2 (rvc_inf, rvc_nan):
|
||
case CLASS2 (rvc_nan, rvc_nan):
|
||
/* ANY + NaN = NaN. */
|
||
case CLASS2 (rvc_normal, rvc_inf):
|
||
/* R + Inf = Inf. */
|
||
*r = *b;
|
||
r->sign = sign ^ subtract_p;
|
||
return;
|
||
|
||
case CLASS2 (rvc_normal, rvc_zero):
|
||
case CLASS2 (rvc_inf, rvc_zero):
|
||
case CLASS2 (rvc_nan, rvc_zero):
|
||
/* ANY + 0 = ANY. */
|
||
case CLASS2 (rvc_nan, rvc_normal):
|
||
case CLASS2 (rvc_nan, rvc_inf):
|
||
/* NaN + ANY = NaN. */
|
||
case CLASS2 (rvc_inf, rvc_normal):
|
||
/* Inf + R = Inf. */
|
||
*r = *a;
|
||
return;
|
||
|
||
case CLASS2 (rvc_inf, rvc_inf):
|
||
if (subtract_p)
|
||
/* Inf - Inf = NaN. */
|
||
get_canonical_qnan (r, 0);
|
||
else
|
||
/* Inf + Inf = Inf. */
|
||
*r = *a;
|
||
return;
|
||
|
||
case CLASS2 (rvc_normal, rvc_normal):
|
||
break;
|
||
|
||
default:
|
||
abort ();
|
||
}
|
||
|
||
/* Swap the arguments such that A has the larger exponent. */
|
||
dexp = a->exp - b->exp;
|
||
if (dexp < 0)
|
||
{
|
||
const REAL_VALUE_TYPE *t;
|
||
t = a, a = b, b = t;
|
||
dexp = -dexp;
|
||
sign ^= subtract_p;
|
||
}
|
||
exp = a->exp;
|
||
|
||
/* If the exponents are not identical, we need to shift the
|
||
significand of B down. */
|
||
if (dexp > 0)
|
||
{
|
||
/* If the exponents are too far apart, the significands
|
||
do not overlap, which makes the subtraction a noop. */
|
||
if (dexp >= SIGNIFICAND_BITS)
|
||
{
|
||
*r = *a;
|
||
r->sign = sign;
|
||
return;
|
||
}
|
||
|
||
inexact |= sticky_rshift_significand (&t, b, dexp);
|
||
b = &t;
|
||
}
|
||
|
||
if (subtract_p)
|
||
{
|
||
if (sub_significands (r, a, b, inexact))
|
||
{
|
||
/* We got a borrow out of the subtraction. That means that
|
||
A and B had the same exponent, and B had the larger
|
||
significand. We need to swap the sign and negate the
|
||
significand. */
|
||
sign ^= 1;
|
||
neg_significand (r, r);
|
||
}
|
||
}
|
||
else
|
||
{
|
||
if (add_significands (r, a, b))
|
||
{
|
||
/* We got carry out of the addition. This means we need to
|
||
shift the significand back down one bit and increase the
|
||
exponent. */
|
||
inexact |= sticky_rshift_significand (r, r, 1);
|
||
r->sig[SIGSZ-1] |= SIG_MSB;
|
||
if (++exp > MAX_EXP)
|
||
{
|
||
get_inf (r, sign);
|
||
return;
|
||
}
|
||
}
|
||
}
|
||
|
||
r->class = rvc_normal;
|
||
r->sign = sign;
|
||
r->exp = exp;
|
||
|
||
/* Re-normalize the result. */
|
||
normalize (r);
|
||
|
||
/* Special case: if the subtraction results in zero, the result
|
||
is positive. */
|
||
if (r->class == rvc_zero)
|
||
r->sign = 0;
|
||
else
|
||
r->sig[0] |= inexact;
|
||
}
|
||
|
||
/* Return R = A * B. */
|
||
|
||
static void
|
||
do_multiply (r, a, b)
|
||
REAL_VALUE_TYPE *r;
|
||
const REAL_VALUE_TYPE *a, *b;
|
||
{
|
||
REAL_VALUE_TYPE u, t, *rr;
|
||
unsigned int i, j, k;
|
||
int sign = a->sign ^ b->sign;
|
||
|
||
switch (CLASS2 (a->class, b->class))
|
||
{
|
||
case CLASS2 (rvc_zero, rvc_zero):
|
||
case CLASS2 (rvc_zero, rvc_normal):
|
||
case CLASS2 (rvc_normal, rvc_zero):
|
||
/* +-0 * ANY = 0 with appropriate sign. */
|
||
get_zero (r, sign);
|
||
return;
|
||
|
||
case CLASS2 (rvc_zero, rvc_nan):
|
||
case CLASS2 (rvc_normal, rvc_nan):
|
||
case CLASS2 (rvc_inf, rvc_nan):
|
||
case CLASS2 (rvc_nan, rvc_nan):
|
||
/* ANY * NaN = NaN. */
|
||
*r = *b;
|
||
r->sign = sign;
|
||
return;
|
||
|
||
case CLASS2 (rvc_nan, rvc_zero):
|
||
case CLASS2 (rvc_nan, rvc_normal):
|
||
case CLASS2 (rvc_nan, rvc_inf):
|
||
/* NaN * ANY = NaN. */
|
||
*r = *a;
|
||
r->sign = sign;
|
||
return;
|
||
|
||
case CLASS2 (rvc_zero, rvc_inf):
|
||
case CLASS2 (rvc_inf, rvc_zero):
|
||
/* 0 * Inf = NaN */
|
||
get_canonical_qnan (r, sign);
|
||
return;
|
||
|
||
case CLASS2 (rvc_inf, rvc_inf):
|
||
case CLASS2 (rvc_normal, rvc_inf):
|
||
case CLASS2 (rvc_inf, rvc_normal):
|
||
/* Inf * Inf = Inf, R * Inf = Inf */
|
||
overflow:
|
||
get_inf (r, sign);
|
||
return;
|
||
|
||
case CLASS2 (rvc_normal, rvc_normal):
|
||
break;
|
||
|
||
default:
|
||
abort ();
|
||
}
|
||
|
||
if (r == a || r == b)
|
||
rr = &t;
|
||
else
|
||
rr = r;
|
||
get_zero (rr, 0);
|
||
|
||
/* Collect all the partial products. Since we don't have sure access
|
||
to a widening multiply, we split each long into two half-words.
|
||
|
||
Consider the long-hand form of a four half-word multiplication:
|
||
|
||
A B C D
|
||
* E F G H
|
||
--------------
|
||
DE DF DG DH
|
||
CE CF CG CH
|
||
BE BF BG BH
|
||
AE AF AG AH
|
||
|
||
We construct partial products of the widened half-word products
|
||
that are known to not overlap, e.g. DF+DH. Each such partial
|
||
product is given its proper exponent, which allows us to sum them
|
||
and obtain the finished product. */
|
||
|
||
for (i = 0; i < SIGSZ * 2; ++i)
|
||
{
|
||
unsigned long ai = a->sig[i / 2];
|
||
if (i & 1)
|
||
ai >>= HOST_BITS_PER_LONG / 2;
|
||
else
|
||
ai &= ((unsigned long)1 << (HOST_BITS_PER_LONG / 2)) - 1;
|
||
|
||
if (ai == 0)
|
||
continue;
|
||
|
||
for (j = 0; j < 2; ++j)
|
||
{
|
||
int exp = (a->exp - (2*SIGSZ-1-i)*(HOST_BITS_PER_LONG/2)
|
||
+ (b->exp - (1-j)*(HOST_BITS_PER_LONG/2)));
|
||
|
||
if (exp > MAX_EXP)
|
||
goto overflow;
|
||
if (exp < -MAX_EXP)
|
||
/* Would underflow to zero, which we shouldn't bother adding. */
|
||
continue;
|
||
|
||
u.class = rvc_normal;
|
||
u.sign = 0;
|
||
u.exp = exp;
|
||
|
||
for (k = j; k < SIGSZ * 2; k += 2)
|
||
{
|
||
unsigned long bi = b->sig[k / 2];
|
||
if (k & 1)
|
||
bi >>= HOST_BITS_PER_LONG / 2;
|
||
else
|
||
bi &= ((unsigned long)1 << (HOST_BITS_PER_LONG / 2)) - 1;
|
||
|
||
u.sig[k / 2] = ai * bi;
|
||
}
|
||
|
||
normalize (&u);
|
||
do_add (rr, rr, &u, 0);
|
||
}
|
||
}
|
||
|
||
rr->sign = sign;
|
||
if (rr != r)
|
||
*r = t;
|
||
}
|
||
|
||
/* Return R = A / B. */
|
||
|
||
static void
|
||
do_divide (r, a, b)
|
||
REAL_VALUE_TYPE *r;
|
||
const REAL_VALUE_TYPE *a, *b;
|
||
{
|
||
int exp, sign = a->sign ^ b->sign;
|
||
REAL_VALUE_TYPE t, *rr;
|
||
bool inexact;
|
||
|
||
switch (CLASS2 (a->class, b->class))
|
||
{
|
||
case CLASS2 (rvc_zero, rvc_zero):
|
||
/* 0 / 0 = NaN. */
|
||
case CLASS2 (rvc_inf, rvc_inf):
|
||
/* Inf / Inf = NaN. */
|
||
get_canonical_qnan (r, sign);
|
||
return;
|
||
|
||
case CLASS2 (rvc_zero, rvc_normal):
|
||
case CLASS2 (rvc_zero, rvc_inf):
|
||
/* 0 / ANY = 0. */
|
||
case CLASS2 (rvc_normal, rvc_inf):
|
||
/* R / Inf = 0. */
|
||
underflow:
|
||
get_zero (r, sign);
|
||
return;
|
||
|
||
case CLASS2 (rvc_normal, rvc_zero):
|
||
/* R / 0 = Inf. */
|
||
case CLASS2 (rvc_inf, rvc_zero):
|
||
/* Inf / 0 = Inf. */
|
||
get_inf (r, sign);
|
||
return;
|
||
|
||
case CLASS2 (rvc_zero, rvc_nan):
|
||
case CLASS2 (rvc_normal, rvc_nan):
|
||
case CLASS2 (rvc_inf, rvc_nan):
|
||
case CLASS2 (rvc_nan, rvc_nan):
|
||
/* ANY / NaN = NaN. */
|
||
*r = *b;
|
||
r->sign = sign;
|
||
return;
|
||
|
||
case CLASS2 (rvc_nan, rvc_zero):
|
||
case CLASS2 (rvc_nan, rvc_normal):
|
||
case CLASS2 (rvc_nan, rvc_inf):
|
||
/* NaN / ANY = NaN. */
|
||
*r = *a;
|
||
r->sign = sign;
|
||
return;
|
||
|
||
case CLASS2 (rvc_inf, rvc_normal):
|
||
/* Inf / R = Inf. */
|
||
overflow:
|
||
get_inf (r, sign);
|
||
return;
|
||
|
||
case CLASS2 (rvc_normal, rvc_normal):
|
||
break;
|
||
|
||
default:
|
||
abort ();
|
||
}
|
||
|
||
if (r == a || r == b)
|
||
rr = &t;
|
||
else
|
||
rr = r;
|
||
|
||
rr->class = rvc_normal;
|
||
rr->sign = sign;
|
||
|
||
exp = a->exp - b->exp + 1;
|
||
if (exp > MAX_EXP)
|
||
goto overflow;
|
||
if (exp < -MAX_EXP)
|
||
goto underflow;
|
||
rr->exp = exp;
|
||
|
||
inexact = div_significands (rr, a, b);
|
||
|
||
/* Re-normalize the result. */
|
||
normalize (rr);
|
||
rr->sig[0] |= inexact;
|
||
|
||
if (rr != r)
|
||
*r = t;
|
||
}
|
||
|
||
/* Return a tri-state comparison of A vs B. Return NAN_RESULT if
|
||
one of the two operands is a NaN. */
|
||
|
||
static int
|
||
do_compare (a, b, nan_result)
|
||
const REAL_VALUE_TYPE *a, *b;
|
||
int nan_result;
|
||
{
|
||
int ret;
|
||
|
||
switch (CLASS2 (a->class, b->class))
|
||
{
|
||
case CLASS2 (rvc_zero, rvc_zero):
|
||
/* Sign of zero doesn't matter for compares. */
|
||
return 0;
|
||
|
||
case CLASS2 (rvc_inf, rvc_zero):
|
||
case CLASS2 (rvc_inf, rvc_normal):
|
||
case CLASS2 (rvc_normal, rvc_zero):
|
||
return (a->sign ? -1 : 1);
|
||
|
||
case CLASS2 (rvc_inf, rvc_inf):
|
||
return -a->sign - -b->sign;
|
||
|
||
case CLASS2 (rvc_zero, rvc_normal):
|
||
case CLASS2 (rvc_zero, rvc_inf):
|
||
case CLASS2 (rvc_normal, rvc_inf):
|
||
return (b->sign ? 1 : -1);
|
||
|
||
case CLASS2 (rvc_zero, rvc_nan):
|
||
case CLASS2 (rvc_normal, rvc_nan):
|
||
case CLASS2 (rvc_inf, rvc_nan):
|
||
case CLASS2 (rvc_nan, rvc_nan):
|
||
case CLASS2 (rvc_nan, rvc_zero):
|
||
case CLASS2 (rvc_nan, rvc_normal):
|
||
case CLASS2 (rvc_nan, rvc_inf):
|
||
return nan_result;
|
||
|
||
case CLASS2 (rvc_normal, rvc_normal):
|
||
break;
|
||
|
||
default:
|
||
abort ();
|
||
}
|
||
|
||
if (a->sign != b->sign)
|
||
return -a->sign - -b->sign;
|
||
|
||
if (a->exp > b->exp)
|
||
ret = 1;
|
||
else if (a->exp < b->exp)
|
||
ret = -1;
|
||
else
|
||
ret = cmp_significands (a, b);
|
||
|
||
return (a->sign ? -ret : ret);
|
||
}
|
||
|
||
/* Return A truncated to an integral value toward zero. */
|
||
|
||
static void
|
||
do_fix_trunc (r, a)
|
||
REAL_VALUE_TYPE *r;
|
||
const REAL_VALUE_TYPE *a;
|
||
{
|
||
*r = *a;
|
||
|
||
switch (r->class)
|
||
{
|
||
case rvc_zero:
|
||
case rvc_inf:
|
||
case rvc_nan:
|
||
break;
|
||
|
||
case rvc_normal:
|
||
if (r->exp <= 0)
|
||
get_zero (r, r->sign);
|
||
else if (r->exp < SIGNIFICAND_BITS)
|
||
clear_significand_below (r, SIGNIFICAND_BITS - r->exp);
|
||
break;
|
||
|
||
default:
|
||
abort ();
|
||
}
|
||
}
|
||
|
||
/* Perform the binary or unary operation described by CODE.
|
||
For a unary operation, leave OP1 NULL. */
|
||
|
||
void
|
||
real_arithmetic (r, icode, op0, op1)
|
||
REAL_VALUE_TYPE *r;
|
||
int icode;
|
||
const REAL_VALUE_TYPE *op0, *op1;
|
||
{
|
||
enum tree_code code = icode;
|
||
|
||
switch (code)
|
||
{
|
||
case PLUS_EXPR:
|
||
do_add (r, op0, op1, 0);
|
||
break;
|
||
|
||
case MINUS_EXPR:
|
||
do_add (r, op0, op1, 1);
|
||
break;
|
||
|
||
case MULT_EXPR:
|
||
do_multiply (r, op0, op1);
|
||
break;
|
||
|
||
case RDIV_EXPR:
|
||
do_divide (r, op0, op1);
|
||
break;
|
||
|
||
case MIN_EXPR:
|
||
if (op1->class == rvc_nan)
|
||
*r = *op1;
|
||
else if (do_compare (op0, op1, -1) < 0)
|
||
*r = *op0;
|
||
else
|
||
*r = *op1;
|
||
break;
|
||
|
||
case MAX_EXPR:
|
||
if (op1->class == rvc_nan)
|
||
*r = *op1;
|
||
else if (do_compare (op0, op1, 1) < 0)
|
||
*r = *op1;
|
||
else
|
||
*r = *op0;
|
||
break;
|
||
|
||
case NEGATE_EXPR:
|
||
*r = *op0;
|
||
r->sign ^= 1;
|
||
break;
|
||
|
||
case ABS_EXPR:
|
||
*r = *op0;
|
||
r->sign = 0;
|
||
break;
|
||
|
||
case FIX_TRUNC_EXPR:
|
||
do_fix_trunc (r, op0);
|
||
break;
|
||
|
||
default:
|
||
abort ();
|
||
}
|
||
}
|
||
|
||
/* Legacy. Similar, but return the result directly. */
|
||
|
||
REAL_VALUE_TYPE
|
||
real_arithmetic2 (icode, op0, op1)
|
||
int icode;
|
||
const REAL_VALUE_TYPE *op0, *op1;
|
||
{
|
||
REAL_VALUE_TYPE r;
|
||
real_arithmetic (&r, icode, op0, op1);
|
||
return r;
|
||
}
|
||
|
||
bool
|
||
real_compare (icode, op0, op1)
|
||
int icode;
|
||
const REAL_VALUE_TYPE *op0, *op1;
|
||
{
|
||
enum tree_code code = icode;
|
||
|
||
switch (code)
|
||
{
|
||
case LT_EXPR:
|
||
return do_compare (op0, op1, 1) < 0;
|
||
case LE_EXPR:
|
||
return do_compare (op0, op1, 1) <= 0;
|
||
case GT_EXPR:
|
||
return do_compare (op0, op1, -1) > 0;
|
||
case GE_EXPR:
|
||
return do_compare (op0, op1, -1) >= 0;
|
||
case EQ_EXPR:
|
||
return do_compare (op0, op1, -1) == 0;
|
||
case NE_EXPR:
|
||
return do_compare (op0, op1, -1) != 0;
|
||
case UNORDERED_EXPR:
|
||
return op0->class == rvc_nan || op1->class == rvc_nan;
|
||
case ORDERED_EXPR:
|
||
return op0->class != rvc_nan && op1->class != rvc_nan;
|
||
case UNLT_EXPR:
|
||
return do_compare (op0, op1, -1) < 0;
|
||
case UNLE_EXPR:
|
||
return do_compare (op0, op1, -1) <= 0;
|
||
case UNGT_EXPR:
|
||
return do_compare (op0, op1, 1) > 0;
|
||
case UNGE_EXPR:
|
||
return do_compare (op0, op1, 1) >= 0;
|
||
case UNEQ_EXPR:
|
||
return do_compare (op0, op1, 0) == 0;
|
||
|
||
default:
|
||
abort ();
|
||
}
|
||
}
|
||
|
||
/* Return floor log2(R). */
|
||
|
||
int
|
||
real_exponent (r)
|
||
const REAL_VALUE_TYPE *r;
|
||
{
|
||
switch (r->class)
|
||
{
|
||
case rvc_zero:
|
||
return 0;
|
||
case rvc_inf:
|
||
case rvc_nan:
|
||
return (unsigned int)-1 >> 1;
|
||
case rvc_normal:
|
||
return r->exp;
|
||
default:
|
||
abort ();
|
||
}
|
||
}
|
||
|
||
/* R = OP0 * 2**EXP. */
|
||
|
||
void
|
||
real_ldexp (r, op0, exp)
|
||
REAL_VALUE_TYPE *r;
|
||
const REAL_VALUE_TYPE *op0;
|
||
int exp;
|
||
{
|
||
*r = *op0;
|
||
switch (r->class)
|
||
{
|
||
case rvc_zero:
|
||
case rvc_inf:
|
||
case rvc_nan:
|
||
break;
|
||
|
||
case rvc_normal:
|
||
exp += op0->exp;
|
||
if (exp > MAX_EXP)
|
||
get_inf (r, r->sign);
|
||
else if (exp < -MAX_EXP)
|
||
get_zero (r, r->sign);
|
||
else
|
||
r->exp = exp;
|
||
break;
|
||
|
||
default:
|
||
abort ();
|
||
}
|
||
}
|
||
|
||
/* Determine whether a floating-point value X is infinite. */
|
||
|
||
bool
|
||
real_isinf (r)
|
||
const REAL_VALUE_TYPE *r;
|
||
{
|
||
return (r->class == rvc_inf);
|
||
}
|
||
|
||
/* Determine whether a floating-point value X is a NaN. */
|
||
|
||
bool
|
||
real_isnan (r)
|
||
const REAL_VALUE_TYPE *r;
|
||
{
|
||
return (r->class == rvc_nan);
|
||
}
|
||
|
||
/* Determine whether a floating-point value X is negative. */
|
||
|
||
bool
|
||
real_isneg (r)
|
||
const REAL_VALUE_TYPE *r;
|
||
{
|
||
return r->sign;
|
||
}
|
||
|
||
/* Determine whether a floating-point value X is minus zero. */
|
||
|
||
bool
|
||
real_isnegzero (r)
|
||
const REAL_VALUE_TYPE *r;
|
||
{
|
||
return r->sign && r->class == rvc_zero;
|
||
}
|
||
|
||
/* Compare two floating-point objects for bitwise identity. */
|
||
|
||
extern bool
|
||
real_identical (a, b)
|
||
const REAL_VALUE_TYPE *a, *b;
|
||
{
|
||
int i;
|
||
|
||
if (a->class != b->class)
|
||
return false;
|
||
if (a->sign != b->sign)
|
||
return false;
|
||
|
||
switch (a->class)
|
||
{
|
||
case rvc_zero:
|
||
case rvc_inf:
|
||
break;
|
||
|
||
case rvc_normal:
|
||
if (a->exp != b->exp)
|
||
return false;
|
||
/* FALLTHRU */
|
||
case rvc_nan:
|
||
for (i = 0; i < SIGSZ; ++i)
|
||
if (a->sig[i] != b->sig[i])
|
||
return false;
|
||
break;
|
||
|
||
default:
|
||
abort ();
|
||
}
|
||
|
||
return true;
|
||
}
|
||
|
||
/* Try to change R into its exact multiplicative inverse in machine
|
||
mode MODE. Return true if successful. */
|
||
|
||
bool
|
||
exact_real_inverse (mode, r)
|
||
enum machine_mode mode;
|
||
REAL_VALUE_TYPE *r;
|
||
{
|
||
const REAL_VALUE_TYPE *one = real_digit (1);
|
||
REAL_VALUE_TYPE u;
|
||
int i;
|
||
|
||
if (r->class != rvc_normal)
|
||
return false;
|
||
|
||
/* Check for a power of two: all significand bits zero except the MSB. */
|
||
for (i = 0; i < SIGSZ-1; ++i)
|
||
if (r->sig[i] != 0)
|
||
return false;
|
||
if (r->sig[SIGSZ-1] != SIG_MSB)
|
||
return false;
|
||
|
||
/* Find the inverse and truncate to the required mode. */
|
||
do_divide (&u, one, r);
|
||
real_convert (&u, mode, &u);
|
||
|
||
/* The rounding may have overflowed. */
|
||
if (u.class != rvc_normal)
|
||
return false;
|
||
for (i = 0; i < SIGSZ-1; ++i)
|
||
if (u.sig[i] != 0)
|
||
return false;
|
||
if (u.sig[SIGSZ-1] != SIG_MSB)
|
||
return false;
|
||
|
||
*r = u;
|
||
return true;
|
||
}
|
||
|
||
/* Render R as an integer. */
|
||
|
||
HOST_WIDE_INT
|
||
real_to_integer (r)
|
||
const REAL_VALUE_TYPE *r;
|
||
{
|
||
unsigned HOST_WIDE_INT i;
|
||
|
||
switch (r->class)
|
||
{
|
||
case rvc_zero:
|
||
underflow:
|
||
return 0;
|
||
|
||
case rvc_inf:
|
||
case rvc_nan:
|
||
overflow:
|
||
i = (unsigned HOST_WIDE_INT) 1 << (HOST_BITS_PER_WIDE_INT - 1);
|
||
if (!r->sign)
|
||
i--;
|
||
return i;
|
||
|
||
case rvc_normal:
|
||
if (r->exp <= 0)
|
||
goto underflow;
|
||
if (r->exp > HOST_BITS_PER_WIDE_INT)
|
||
goto overflow;
|
||
|
||
if (HOST_BITS_PER_WIDE_INT == HOST_BITS_PER_LONG)
|
||
i = r->sig[SIGSZ-1];
|
||
else if (HOST_BITS_PER_WIDE_INT == 2*HOST_BITS_PER_LONG)
|
||
{
|
||
i = r->sig[SIGSZ-1];
|
||
i = i << (HOST_BITS_PER_LONG - 1) << 1;
|
||
i |= r->sig[SIGSZ-2];
|
||
}
|
||
else
|
||
abort ();
|
||
|
||
i >>= HOST_BITS_PER_WIDE_INT - r->exp;
|
||
|
||
if (r->sign)
|
||
i = -i;
|
||
return i;
|
||
|
||
default:
|
||
abort ();
|
||
}
|
||
}
|
||
|
||
/* Likewise, but to an integer pair, HI+LOW. */
|
||
|
||
void
|
||
real_to_integer2 (plow, phigh, r)
|
||
HOST_WIDE_INT *plow, *phigh;
|
||
const REAL_VALUE_TYPE *r;
|
||
{
|
||
REAL_VALUE_TYPE t;
|
||
HOST_WIDE_INT low, high;
|
||
int exp;
|
||
|
||
switch (r->class)
|
||
{
|
||
case rvc_zero:
|
||
underflow:
|
||
low = high = 0;
|
||
break;
|
||
|
||
case rvc_inf:
|
||
case rvc_nan:
|
||
overflow:
|
||
high = (unsigned HOST_WIDE_INT) 1 << (HOST_BITS_PER_WIDE_INT - 1);
|
||
if (r->sign)
|
||
low = 0;
|
||
else
|
||
{
|
||
high--;
|
||
low = -1;
|
||
}
|
||
break;
|
||
|
||
case rvc_normal:
|
||
exp = r->exp;
|
||
if (exp <= 0)
|
||
goto underflow;
|
||
if (exp > 2*HOST_BITS_PER_WIDE_INT)
|
||
goto overflow;
|
||
|
||
rshift_significand (&t, r, 2*HOST_BITS_PER_WIDE_INT - exp);
|
||
if (HOST_BITS_PER_WIDE_INT == HOST_BITS_PER_LONG)
|
||
{
|
||
high = t.sig[SIGSZ-1];
|
||
low = t.sig[SIGSZ-2];
|
||
}
|
||
else if (HOST_BITS_PER_WIDE_INT == 2*HOST_BITS_PER_LONG)
|
||
{
|
||
high = t.sig[SIGSZ-1];
|
||
high = high << (HOST_BITS_PER_LONG - 1) << 1;
|
||
high |= t.sig[SIGSZ-2];
|
||
|
||
low = t.sig[SIGSZ-3];
|
||
low = low << (HOST_BITS_PER_LONG - 1) << 1;
|
||
low |= t.sig[SIGSZ-4];
|
||
}
|
||
else
|
||
abort ();
|
||
|
||
if (r->sign)
|
||
{
|
||
if (low == 0)
|
||
high = -high;
|
||
else
|
||
low = -low, high = ~high;
|
||
}
|
||
break;
|
||
|
||
default:
|
||
abort ();
|
||
}
|
||
|
||
*plow = low;
|
||
*phigh = high;
|
||
}
|
||
|
||
/* A subroutine of real_to_decimal. Compute the quotient and remainder
|
||
of NUM / DEN. Return the quotient and place the remainder in NUM.
|
||
It is expected that NUM / DEN are close enough that the quotient is
|
||
small. */
|
||
|
||
static unsigned long
|
||
rtd_divmod (num, den)
|
||
REAL_VALUE_TYPE *num, *den;
|
||
{
|
||
unsigned long q, msb;
|
||
int expn = num->exp, expd = den->exp;
|
||
|
||
if (expn < expd)
|
||
return 0;
|
||
|
||
q = msb = 0;
|
||
goto start;
|
||
do
|
||
{
|
||
msb = num->sig[SIGSZ-1] & SIG_MSB;
|
||
q <<= 1;
|
||
lshift_significand_1 (num, num);
|
||
start:
|
||
if (msb || cmp_significands (num, den) >= 0)
|
||
{
|
||
sub_significands (num, num, den, 0);
|
||
q |= 1;
|
||
}
|
||
}
|
||
while (--expn >= expd);
|
||
|
||
num->exp = expd;
|
||
normalize (num);
|
||
|
||
return q;
|
||
}
|
||
|
||
/* Render R as a decimal floating point constant. Emit DIGITS significant
|
||
digits in the result, bounded by BUF_SIZE. If DIGITS is 0, choose the
|
||
maximum for the representation. If CROP_TRAILING_ZEROS, strip trailing
|
||
zeros. */
|
||
|
||
#define M_LOG10_2 0.30102999566398119521
|
||
|
||
void
|
||
real_to_decimal (str, r_orig, buf_size, digits, crop_trailing_zeros)
|
||
char *str;
|
||
const REAL_VALUE_TYPE *r_orig;
|
||
size_t buf_size, digits;
|
||
int crop_trailing_zeros;
|
||
{
|
||
const REAL_VALUE_TYPE *one, *ten;
|
||
REAL_VALUE_TYPE r, pten, u, v;
|
||
int dec_exp, cmp_one, digit;
|
||
size_t max_digits;
|
||
char *p, *first, *last;
|
||
bool sign;
|
||
|
||
r = *r_orig;
|
||
switch (r.class)
|
||
{
|
||
case rvc_zero:
|
||
strcpy (str, (r.sign ? "-0.0" : "0.0"));
|
||
return;
|
||
case rvc_normal:
|
||
break;
|
||
case rvc_inf:
|
||
strcpy (str, (r.sign ? "-Inf" : "+Inf"));
|
||
return;
|
||
case rvc_nan:
|
||
/* ??? Print the significand as well, if not canonical? */
|
||
strcpy (str, (r.sign ? "-NaN" : "+NaN"));
|
||
return;
|
||
default:
|
||
abort ();
|
||
}
|
||
|
||
/* Bound the number of digits printed by the size of the representation. */
|
||
max_digits = SIGNIFICAND_BITS * M_LOG10_2;
|
||
if (digits == 0 || digits > max_digits)
|
||
digits = max_digits;
|
||
|
||
/* Estimate the decimal exponent, and compute the length of the string it
|
||
will print as. Be conservative and add one to account for possible
|
||
overflow or rounding error. */
|
||
dec_exp = r.exp * M_LOG10_2;
|
||
for (max_digits = 1; dec_exp ; max_digits++)
|
||
dec_exp /= 10;
|
||
|
||
/* Bound the number of digits printed by the size of the output buffer. */
|
||
max_digits = buf_size - 1 - 1 - 2 - max_digits - 1;
|
||
if (max_digits > buf_size)
|
||
abort ();
|
||
if (digits > max_digits)
|
||
digits = max_digits;
|
||
|
||
one = real_digit (1);
|
||
ten = ten_to_ptwo (0);
|
||
|
||
sign = r.sign;
|
||
r.sign = 0;
|
||
|
||
dec_exp = 0;
|
||
pten = *one;
|
||
|
||
cmp_one = do_compare (&r, one, 0);
|
||
if (cmp_one > 0)
|
||
{
|
||
int m;
|
||
|
||
/* Number is greater than one. Convert significand to an integer
|
||
and strip trailing decimal zeros. */
|
||
|
||
u = r;
|
||
u.exp = SIGNIFICAND_BITS - 1;
|
||
|
||
/* Largest M, such that 10**2**M fits within SIGNIFICAND_BITS. */
|
||
m = floor_log2 (max_digits);
|
||
|
||
/* Iterate over the bits of the possible powers of 10 that might
|
||
be present in U and eliminate them. That is, if we find that
|
||
10**2**M divides U evenly, keep the division and increase
|
||
DEC_EXP by 2**M. */
|
||
do
|
||
{
|
||
REAL_VALUE_TYPE t;
|
||
|
||
do_divide (&t, &u, ten_to_ptwo (m));
|
||
do_fix_trunc (&v, &t);
|
||
if (cmp_significands (&v, &t) == 0)
|
||
{
|
||
u = t;
|
||
dec_exp += 1 << m;
|
||
}
|
||
}
|
||
while (--m >= 0);
|
||
|
||
/* Revert the scaling to integer that we performed earlier. */
|
||
u.exp += r.exp - (SIGNIFICAND_BITS - 1);
|
||
r = u;
|
||
|
||
/* Find power of 10. Do this by dividing out 10**2**M when
|
||
this is larger than the current remainder. Fill PTEN with
|
||
the power of 10 that we compute. */
|
||
if (r.exp > 0)
|
||
{
|
||
m = floor_log2 ((int)(r.exp * M_LOG10_2)) + 1;
|
||
do
|
||
{
|
||
const REAL_VALUE_TYPE *ptentwo = ten_to_ptwo (m);
|
||
if (do_compare (&u, ptentwo, 0) >= 0)
|
||
{
|
||
do_divide (&u, &u, ptentwo);
|
||
do_multiply (&pten, &pten, ptentwo);
|
||
dec_exp += 1 << m;
|
||
}
|
||
}
|
||
while (--m >= 0);
|
||
}
|
||
else
|
||
/* We managed to divide off enough tens in the above reduction
|
||
loop that we've now got a negative exponent. Fall into the
|
||
less-than-one code to compute the proper value for PTEN. */
|
||
cmp_one = -1;
|
||
}
|
||
if (cmp_one < 0)
|
||
{
|
||
int m;
|
||
|
||
/* Number is less than one. Pad significand with leading
|
||
decimal zeros. */
|
||
|
||
v = r;
|
||
while (1)
|
||
{
|
||
/* Stop if we'd shift bits off the bottom. */
|
||
if (v.sig[0] & 7)
|
||
break;
|
||
|
||
do_multiply (&u, &v, ten);
|
||
|
||
/* Stop if we're now >= 1. */
|
||
if (u.exp > 0)
|
||
break;
|
||
|
||
v = u;
|
||
dec_exp -= 1;
|
||
}
|
||
r = v;
|
||
|
||
/* Find power of 10. Do this by multiplying in P=10**2**M when
|
||
the current remainder is smaller than 1/P. Fill PTEN with the
|
||
power of 10 that we compute. */
|
||
m = floor_log2 ((int)(-r.exp * M_LOG10_2)) + 1;
|
||
do
|
||
{
|
||
const REAL_VALUE_TYPE *ptentwo = ten_to_ptwo (m);
|
||
const REAL_VALUE_TYPE *ptenmtwo = ten_to_mptwo (m);
|
||
|
||
if (do_compare (&v, ptenmtwo, 0) <= 0)
|
||
{
|
||
do_multiply (&v, &v, ptentwo);
|
||
do_multiply (&pten, &pten, ptentwo);
|
||
dec_exp -= 1 << m;
|
||
}
|
||
}
|
||
while (--m >= 0);
|
||
|
||
/* Invert the positive power of 10 that we've collected so far. */
|
||
do_divide (&pten, one, &pten);
|
||
}
|
||
|
||
p = str;
|
||
if (sign)
|
||
*p++ = '-';
|
||
first = p++;
|
||
|
||
/* At this point, PTEN should contain the nearest power of 10 smaller
|
||
than R, such that this division produces the first digit.
|
||
|
||
Using a divide-step primitive that returns the complete integral
|
||
remainder avoids the rounding error that would be produced if
|
||
we were to use do_divide here and then simply multiply by 10 for
|
||
each subsequent digit. */
|
||
|
||
digit = rtd_divmod (&r, &pten);
|
||
|
||
/* Be prepared for error in that division via underflow ... */
|
||
if (digit == 0 && cmp_significand_0 (&r))
|
||
{
|
||
/* Multiply by 10 and try again. */
|
||
do_multiply (&r, &r, ten);
|
||
digit = rtd_divmod (&r, &pten);
|
||
dec_exp -= 1;
|
||
if (digit == 0)
|
||
abort ();
|
||
}
|
||
|
||
/* ... or overflow. */
|
||
if (digit == 10)
|
||
{
|
||
*p++ = '1';
|
||
if (--digits > 0)
|
||
*p++ = '0';
|
||
dec_exp += 1;
|
||
}
|
||
else if (digit > 10)
|
||
abort ();
|
||
else
|
||
*p++ = digit + '0';
|
||
|
||
/* Generate subsequent digits. */
|
||
while (--digits > 0)
|
||
{
|
||
do_multiply (&r, &r, ten);
|
||
digit = rtd_divmod (&r, &pten);
|
||
*p++ = digit + '0';
|
||
}
|
||
last = p;
|
||
|
||
/* Generate one more digit with which to do rounding. */
|
||
do_multiply (&r, &r, ten);
|
||
digit = rtd_divmod (&r, &pten);
|
||
|
||
/* Round the result. */
|
||
if (digit == 5)
|
||
{
|
||
/* Round to nearest. If R is nonzero there are additional
|
||
nonzero digits to be extracted. */
|
||
if (cmp_significand_0 (&r))
|
||
digit++;
|
||
/* Round to even. */
|
||
else if ((p[-1] - '0') & 1)
|
||
digit++;
|
||
}
|
||
if (digit > 5)
|
||
{
|
||
while (p > first)
|
||
{
|
||
digit = *--p;
|
||
if (digit == '9')
|
||
*p = '0';
|
||
else
|
||
{
|
||
*p = digit + 1;
|
||
break;
|
||
}
|
||
}
|
||
|
||
/* Carry out of the first digit. This means we had all 9's and
|
||
now have all 0's. "Prepend" a 1 by overwriting the first 0. */
|
||
if (p == first)
|
||
{
|
||
first[1] = '1';
|
||
dec_exp++;
|
||
}
|
||
}
|
||
|
||
/* Insert the decimal point. */
|
||
first[0] = first[1];
|
||
first[1] = '.';
|
||
|
||
/* If requested, drop trailing zeros. Never crop past "1.0". */
|
||
if (crop_trailing_zeros)
|
||
while (last > first + 3 && last[-1] == '0')
|
||
last--;
|
||
|
||
/* Append the exponent. */
|
||
sprintf (last, "e%+d", dec_exp);
|
||
}
|
||
|
||
/* Render R as a hexadecimal floating point constant. Emit DIGITS
|
||
significant digits in the result, bounded by BUF_SIZE. If DIGITS is 0,
|
||
choose the maximum for the representation. If CROP_TRAILING_ZEROS,
|
||
strip trailing zeros. */
|
||
|
||
void
|
||
real_to_hexadecimal (str, r, buf_size, digits, crop_trailing_zeros)
|
||
char *str;
|
||
const REAL_VALUE_TYPE *r;
|
||
size_t buf_size, digits;
|
||
int crop_trailing_zeros;
|
||
{
|
||
int i, j, exp = r->exp;
|
||
char *p, *first;
|
||
char exp_buf[16];
|
||
size_t max_digits;
|
||
|
||
switch (r->class)
|
||
{
|
||
case rvc_zero:
|
||
exp = 0;
|
||
break;
|
||
case rvc_normal:
|
||
break;
|
||
case rvc_inf:
|
||
strcpy (str, (r->sign ? "-Inf" : "+Inf"));
|
||
return;
|
||
case rvc_nan:
|
||
/* ??? Print the significand as well, if not canonical? */
|
||
strcpy (str, (r->sign ? "-NaN" : "+NaN"));
|
||
return;
|
||
default:
|
||
abort ();
|
||
}
|
||
|
||
if (digits == 0)
|
||
digits = SIGNIFICAND_BITS / 4;
|
||
|
||
/* Bound the number of digits printed by the size of the output buffer. */
|
||
|
||
sprintf (exp_buf, "p%+d", exp);
|
||
max_digits = buf_size - strlen (exp_buf) - r->sign - 4 - 1;
|
||
if (max_digits > buf_size)
|
||
abort ();
|
||
if (digits > max_digits)
|
||
digits = max_digits;
|
||
|
||
p = str;
|
||
if (r->sign)
|
||
*p++ = '-';
|
||
*p++ = '0';
|
||
*p++ = 'x';
|
||
*p++ = '0';
|
||
*p++ = '.';
|
||
first = p;
|
||
|
||
for (i = SIGSZ - 1; i >= 0; --i)
|
||
for (j = HOST_BITS_PER_LONG - 4; j >= 0; j -= 4)
|
||
{
|
||
*p++ = "0123456789abcdef"[(r->sig[i] >> j) & 15];
|
||
if (--digits == 0)
|
||
goto out;
|
||
}
|
||
|
||
out:
|
||
if (crop_trailing_zeros)
|
||
while (p > first + 1 && p[-1] == '0')
|
||
p--;
|
||
|
||
sprintf (p, "p%+d", exp);
|
||
}
|
||
|
||
/* Initialize R from a decimal or hexadecimal string. The string is
|
||
assumed to have been syntax checked already. */
|
||
|
||
void
|
||
real_from_string (r, str)
|
||
REAL_VALUE_TYPE *r;
|
||
const char *str;
|
||
{
|
||
int exp = 0;
|
||
bool sign = false;
|
||
|
||
get_zero (r, 0);
|
||
|
||
if (*str == '-')
|
||
{
|
||
sign = true;
|
||
str++;
|
||
}
|
||
else if (*str == '+')
|
||
str++;
|
||
|
||
if (str[0] == '0' && str[1] == 'x')
|
||
{
|
||
/* Hexadecimal floating point. */
|
||
int pos = SIGNIFICAND_BITS - 4, d;
|
||
|
||
str += 2;
|
||
|
||
while (*str == '0')
|
||
str++;
|
||
while (1)
|
||
{
|
||
d = hex_value (*str);
|
||
if (d == _hex_bad)
|
||
break;
|
||
if (pos >= 0)
|
||
{
|
||
r->sig[pos / HOST_BITS_PER_LONG]
|
||
|= (unsigned long) d << (pos % HOST_BITS_PER_LONG);
|
||
pos -= 4;
|
||
}
|
||
exp += 4;
|
||
str++;
|
||
}
|
||
if (*str == '.')
|
||
{
|
||
str++;
|
||
if (pos == SIGNIFICAND_BITS - 4)
|
||
{
|
||
while (*str == '0')
|
||
str++, exp -= 4;
|
||
}
|
||
while (1)
|
||
{
|
||
d = hex_value (*str);
|
||
if (d == _hex_bad)
|
||
break;
|
||
if (pos >= 0)
|
||
{
|
||
r->sig[pos / HOST_BITS_PER_LONG]
|
||
|= (unsigned long) d << (pos % HOST_BITS_PER_LONG);
|
||
pos -= 4;
|
||
}
|
||
str++;
|
||
}
|
||
}
|
||
if (*str == 'p' || *str == 'P')
|
||
{
|
||
bool exp_neg = false;
|
||
|
||
str++;
|
||
if (*str == '-')
|
||
{
|
||
exp_neg = true;
|
||
str++;
|
||
}
|
||
else if (*str == '+')
|
||
str++;
|
||
|
||
d = 0;
|
||
while (ISDIGIT (*str))
|
||
{
|
||
d *= 10;
|
||
d += *str - '0';
|
||
if (d > MAX_EXP)
|
||
{
|
||
/* Overflowed the exponent. */
|
||
if (exp_neg)
|
||
goto underflow;
|
||
else
|
||
goto overflow;
|
||
}
|
||
str++;
|
||
}
|
||
if (exp_neg)
|
||
d = -d;
|
||
|
||
exp += d;
|
||
}
|
||
|
||
r->class = rvc_normal;
|
||
r->exp = exp;
|
||
|
||
normalize (r);
|
||
}
|
||
else
|
||
{
|
||
/* Decimal floating point. */
|
||
const REAL_VALUE_TYPE *ten = ten_to_ptwo (0);
|
||
int d;
|
||
|
||
while (*str == '0')
|
||
str++;
|
||
while (ISDIGIT (*str))
|
||
{
|
||
d = *str++ - '0';
|
||
do_multiply (r, r, ten);
|
||
if (d)
|
||
do_add (r, r, real_digit (d), 0);
|
||
}
|
||
if (*str == '.')
|
||
{
|
||
str++;
|
||
if (r->class == rvc_zero)
|
||
{
|
||
while (*str == '0')
|
||
str++, exp--;
|
||
}
|
||
while (ISDIGIT (*str))
|
||
{
|
||
d = *str++ - '0';
|
||
do_multiply (r, r, ten);
|
||
if (d)
|
||
do_add (r, r, real_digit (d), 0);
|
||
exp--;
|
||
}
|
||
}
|
||
|
||
if (*str == 'e' || *str == 'E')
|
||
{
|
||
bool exp_neg = false;
|
||
|
||
str++;
|
||
if (*str == '-')
|
||
{
|
||
exp_neg = true;
|
||
str++;
|
||
}
|
||
else if (*str == '+')
|
||
str++;
|
||
|
||
d = 0;
|
||
while (ISDIGIT (*str))
|
||
{
|
||
d *= 10;
|
||
d += *str - '0';
|
||
if (d > MAX_EXP)
|
||
{
|
||
/* Overflowed the exponent. */
|
||
if (exp_neg)
|
||
goto underflow;
|
||
else
|
||
goto overflow;
|
||
}
|
||
str++;
|
||
}
|
||
if (exp_neg)
|
||
d = -d;
|
||
exp += d;
|
||
}
|
||
|
||
if (exp)
|
||
times_pten (r, exp);
|
||
}
|
||
|
||
r->sign = sign;
|
||
return;
|
||
|
||
underflow:
|
||
get_zero (r, sign);
|
||
return;
|
||
|
||
overflow:
|
||
get_inf (r, sign);
|
||
return;
|
||
}
|
||
|
||
/* Legacy. Similar, but return the result directly. */
|
||
|
||
REAL_VALUE_TYPE
|
||
real_from_string2 (s, mode)
|
||
const char *s;
|
||
enum machine_mode mode;
|
||
{
|
||
REAL_VALUE_TYPE r;
|
||
|
||
real_from_string (&r, s);
|
||
if (mode != VOIDmode)
|
||
real_convert (&r, mode, &r);
|
||
|
||
return r;
|
||
}
|
||
|
||
/* Initialize R from the integer pair HIGH+LOW. */
|
||
|
||
void
|
||
real_from_integer (r, mode, low, high, unsigned_p)
|
||
REAL_VALUE_TYPE *r;
|
||
enum machine_mode mode;
|
||
unsigned HOST_WIDE_INT low;
|
||
HOST_WIDE_INT high;
|
||
int unsigned_p;
|
||
{
|
||
if (low == 0 && high == 0)
|
||
get_zero (r, 0);
|
||
else
|
||
{
|
||
r->class = rvc_normal;
|
||
r->sign = high < 0 && !unsigned_p;
|
||
r->exp = 2 * HOST_BITS_PER_WIDE_INT;
|
||
|
||
if (r->sign)
|
||
{
|
||
high = ~high;
|
||
if (low == 0)
|
||
high += 1;
|
||
else
|
||
low = -low;
|
||
}
|
||
|
||
if (HOST_BITS_PER_LONG == HOST_BITS_PER_WIDE_INT)
|
||
{
|
||
r->sig[SIGSZ-1] = high;
|
||
r->sig[SIGSZ-2] = low;
|
||
memset (r->sig, 0, sizeof(long)*(SIGSZ-2));
|
||
}
|
||
else if (HOST_BITS_PER_LONG*2 == HOST_BITS_PER_WIDE_INT)
|
||
{
|
||
r->sig[SIGSZ-1] = high >> (HOST_BITS_PER_LONG - 1) >> 1;
|
||
r->sig[SIGSZ-2] = high;
|
||
r->sig[SIGSZ-3] = low >> (HOST_BITS_PER_LONG - 1) >> 1;
|
||
r->sig[SIGSZ-4] = low;
|
||
if (SIGSZ > 4)
|
||
memset (r->sig, 0, sizeof(long)*(SIGSZ-4));
|
||
}
|
||
else
|
||
abort ();
|
||
|
||
normalize (r);
|
||
}
|
||
|
||
if (mode != VOIDmode)
|
||
real_convert (r, mode, r);
|
||
}
|
||
|
||
/* Returns 10**2**N. */
|
||
|
||
static const REAL_VALUE_TYPE *
|
||
ten_to_ptwo (n)
|
||
int n;
|
||
{
|
||
static REAL_VALUE_TYPE tens[EXP_BITS];
|
||
|
||
if (n < 0 || n >= EXP_BITS)
|
||
abort ();
|
||
|
||
if (tens[n].class == rvc_zero)
|
||
{
|
||
if (n < (HOST_BITS_PER_WIDE_INT == 64 ? 5 : 4))
|
||
{
|
||
HOST_WIDE_INT t = 10;
|
||
int i;
|
||
|
||
for (i = 0; i < n; ++i)
|
||
t *= t;
|
||
|
||
real_from_integer (&tens[n], VOIDmode, t, 0, 1);
|
||
}
|
||
else
|
||
{
|
||
const REAL_VALUE_TYPE *t = ten_to_ptwo (n - 1);
|
||
do_multiply (&tens[n], t, t);
|
||
}
|
||
}
|
||
|
||
return &tens[n];
|
||
}
|
||
|
||
/* Returns 10**(-2**N). */
|
||
|
||
static const REAL_VALUE_TYPE *
|
||
ten_to_mptwo (n)
|
||
int n;
|
||
{
|
||
static REAL_VALUE_TYPE tens[EXP_BITS];
|
||
|
||
if (n < 0 || n >= EXP_BITS)
|
||
abort ();
|
||
|
||
if (tens[n].class == rvc_zero)
|
||
do_divide (&tens[n], real_digit (1), ten_to_ptwo (n));
|
||
|
||
return &tens[n];
|
||
}
|
||
|
||
/* Returns N. */
|
||
|
||
static const REAL_VALUE_TYPE *
|
||
real_digit (n)
|
||
int n;
|
||
{
|
||
static REAL_VALUE_TYPE num[10];
|
||
|
||
if (n < 0 || n > 9)
|
||
abort ();
|
||
|
||
if (n > 0 && num[n].class == rvc_zero)
|
||
real_from_integer (&num[n], VOIDmode, n, 0, 1);
|
||
|
||
return &num[n];
|
||
}
|
||
|
||
/* Multiply R by 10**EXP. */
|
||
|
||
static void
|
||
times_pten (r, exp)
|
||
REAL_VALUE_TYPE *r;
|
||
int exp;
|
||
{
|
||
REAL_VALUE_TYPE pten, *rr;
|
||
bool negative = (exp < 0);
|
||
int i;
|
||
|
||
if (negative)
|
||
{
|
||
exp = -exp;
|
||
pten = *real_digit (1);
|
||
rr = &pten;
|
||
}
|
||
else
|
||
rr = r;
|
||
|
||
for (i = 0; exp > 0; ++i, exp >>= 1)
|
||
if (exp & 1)
|
||
do_multiply (rr, rr, ten_to_ptwo (i));
|
||
|
||
if (negative)
|
||
do_divide (r, r, &pten);
|
||
}
|
||
|
||
/* Fills R with +Inf. */
|
||
|
||
void
|
||
real_inf (r)
|
||
REAL_VALUE_TYPE *r;
|
||
{
|
||
get_inf (r, 0);
|
||
}
|
||
|
||
/* Fills R with a NaN whose significand is described by STR. If QUIET,
|
||
we force a QNaN, else we force an SNaN. The string, if not empty,
|
||
is parsed as a number and placed in the significand. Return true
|
||
if the string was successfully parsed. */
|
||
|
||
bool
|
||
real_nan (r, str, quiet, mode)
|
||
REAL_VALUE_TYPE *r;
|
||
const char *str;
|
||
int quiet;
|
||
enum machine_mode mode;
|
||
{
|
||
const struct real_format *fmt;
|
||
|
||
fmt = real_format_for_mode[mode - QFmode];
|
||
if (fmt == NULL)
|
||
abort ();
|
||
|
||
if (*str == 0)
|
||
{
|
||
if (quiet)
|
||
get_canonical_qnan (r, 0);
|
||
else
|
||
get_canonical_snan (r, 0);
|
||
}
|
||
else
|
||
{
|
||
int base = 10, d;
|
||
bool neg = false;
|
||
|
||
memset (r, 0, sizeof (*r));
|
||
r->class = rvc_nan;
|
||
|
||
/* Parse akin to strtol into the significand of R. */
|
||
|
||
while (ISSPACE (*str))
|
||
str++;
|
||
if (*str == '-')
|
||
str++, neg = true;
|
||
else if (*str == '+')
|
||
str++;
|
||
if (*str == '0')
|
||
{
|
||
if (*++str == 'x')
|
||
str++, base = 16;
|
||
else
|
||
base = 8;
|
||
}
|
||
|
||
while ((d = hex_value (*str)) < base)
|
||
{
|
||
REAL_VALUE_TYPE u;
|
||
|
||
switch (base)
|
||
{
|
||
case 8:
|
||
lshift_significand (r, r, 3);
|
||
break;
|
||
case 16:
|
||
lshift_significand (r, r, 4);
|
||
break;
|
||
case 10:
|
||
lshift_significand_1 (&u, r);
|
||
lshift_significand (r, r, 3);
|
||
add_significands (r, r, &u);
|
||
break;
|
||
default:
|
||
abort ();
|
||
}
|
||
|
||
get_zero (&u, 0);
|
||
u.sig[0] = d;
|
||
add_significands (r, r, &u);
|
||
|
||
str++;
|
||
}
|
||
|
||
/* Must have consumed the entire string for success. */
|
||
if (*str != 0)
|
||
return false;
|
||
|
||
/* Shift the significand into place such that the bits
|
||
are in the most significant bits for the format. */
|
||
lshift_significand (r, r, SIGNIFICAND_BITS - fmt->p);
|
||
|
||
/* Our MSB is always unset for NaNs. */
|
||
r->sig[SIGSZ-1] &= ~SIG_MSB;
|
||
|
||
/* Force quiet or signalling NaN. */
|
||
if (quiet)
|
||
r->sig[SIGSZ-1] |= SIG_MSB >> 1;
|
||
else
|
||
r->sig[SIGSZ-1] &= ~(SIG_MSB >> 1);
|
||
|
||
/* Force at least one bit of the significand set. */
|
||
for (d = 0; d < SIGSZ; ++d)
|
||
if (r->sig[d])
|
||
break;
|
||
if (d == SIGSZ)
|
||
r->sig[SIGSZ-1] |= SIG_MSB >> 2;
|
||
|
||
/* Our intermediate format forces QNaNs to have MSB-1 set.
|
||
If the target format has QNaNs with the top bit unset,
|
||
mirror the output routines and invert the top two bits. */
|
||
if (!fmt->qnan_msb_set)
|
||
r->sig[SIGSZ-1] ^= (SIG_MSB >> 1) | (SIG_MSB >> 2);
|
||
}
|
||
|
||
return true;
|
||
}
|
||
|
||
/* Fills R with 2**N. */
|
||
|
||
void
|
||
real_2expN (r, n)
|
||
REAL_VALUE_TYPE *r;
|
||
int n;
|
||
{
|
||
memset (r, 0, sizeof (*r));
|
||
|
||
n++;
|
||
if (n > MAX_EXP)
|
||
r->class = rvc_inf;
|
||
else if (n < -MAX_EXP)
|
||
;
|
||
else
|
||
{
|
||
r->class = rvc_normal;
|
||
r->exp = n;
|
||
r->sig[SIGSZ-1] = SIG_MSB;
|
||
}
|
||
}
|
||
|
||
|
||
static void
|
||
round_for_format (fmt, r)
|
||
const struct real_format *fmt;
|
||
REAL_VALUE_TYPE *r;
|
||
{
|
||
int p2, np2, i, w;
|
||
unsigned long sticky;
|
||
bool guard, lsb;
|
||
int emin2m1, emax2;
|
||
|
||
p2 = fmt->p * fmt->log2_b;
|
||
emin2m1 = (fmt->emin - 1) * fmt->log2_b;
|
||
emax2 = fmt->emax * fmt->log2_b;
|
||
|
||
np2 = SIGNIFICAND_BITS - p2;
|
||
switch (r->class)
|
||
{
|
||
underflow:
|
||
get_zero (r, r->sign);
|
||
case rvc_zero:
|
||
if (!fmt->has_signed_zero)
|
||
r->sign = 0;
|
||
return;
|
||
|
||
overflow:
|
||
get_inf (r, r->sign);
|
||
case rvc_inf:
|
||
return;
|
||
|
||
case rvc_nan:
|
||
clear_significand_below (r, np2);
|
||
|
||
/* If we've cleared the entire significand, we need one bit
|
||
set for this to continue to be a NaN. */
|
||
for (i = 0; i < SIGSZ; ++i)
|
||
if (r->sig[i])
|
||
break;
|
||
if (i == SIGSZ)
|
||
r->sig[SIGSZ-1] = SIG_MSB >> 2;
|
||
return;
|
||
|
||
case rvc_normal:
|
||
break;
|
||
|
||
default:
|
||
abort ();
|
||
}
|
||
|
||
/* If we're not base2, normalize the exponent to a multiple of
|
||
the true base. */
|
||
if (fmt->log2_b != 1)
|
||
{
|
||
int shift = r->exp & (fmt->log2_b - 1);
|
||
if (shift)
|
||
{
|
||
shift = fmt->log2_b - shift;
|
||
r->sig[0] |= sticky_rshift_significand (r, r, shift);
|
||
r->exp += shift;
|
||
}
|
||
}
|
||
|
||
/* Check the range of the exponent. If we're out of range,
|
||
either underflow or overflow. */
|
||
if (r->exp > emax2)
|
||
goto overflow;
|
||
else if (r->exp <= emin2m1)
|
||
{
|
||
int diff;
|
||
|
||
if (!fmt->has_denorm)
|
||
{
|
||
/* Don't underflow completely until we've had a chance to round. */
|
||
if (r->exp < emin2m1)
|
||
goto underflow;
|
||
}
|
||
else
|
||
{
|
||
diff = emin2m1 - r->exp + 1;
|
||
if (diff > p2)
|
||
goto underflow;
|
||
|
||
/* De-normalize the significand. */
|
||
r->sig[0] |= sticky_rshift_significand (r, r, diff);
|
||
r->exp += diff;
|
||
}
|
||
}
|
||
|
||
/* There are P2 true significand bits, followed by one guard bit,
|
||
followed by one sticky bit, followed by stuff. Fold nonzero
|
||
stuff into the sticky bit. */
|
||
|
||
sticky = 0;
|
||
for (i = 0, w = (np2 - 1) / HOST_BITS_PER_LONG; i < w; ++i)
|
||
sticky |= r->sig[i];
|
||
sticky |=
|
||
r->sig[w] & (((unsigned long)1 << ((np2 - 1) % HOST_BITS_PER_LONG)) - 1);
|
||
|
||
guard = test_significand_bit (r, np2 - 1);
|
||
lsb = test_significand_bit (r, np2);
|
||
|
||
/* Round to even. */
|
||
if (guard && (sticky || lsb))
|
||
{
|
||
REAL_VALUE_TYPE u;
|
||
get_zero (&u, 0);
|
||
set_significand_bit (&u, np2);
|
||
|
||
if (add_significands (r, r, &u))
|
||
{
|
||
/* Overflow. Means the significand had been all ones, and
|
||
is now all zeros. Need to increase the exponent, and
|
||
possibly re-normalize it. */
|
||
if (++r->exp > emax2)
|
||
goto overflow;
|
||
r->sig[SIGSZ-1] = SIG_MSB;
|
||
|
||
if (fmt->log2_b != 1)
|
||
{
|
||
int shift = r->exp & (fmt->log2_b - 1);
|
||
if (shift)
|
||
{
|
||
shift = fmt->log2_b - shift;
|
||
rshift_significand (r, r, shift);
|
||
r->exp += shift;
|
||
if (r->exp > emax2)
|
||
goto overflow;
|
||
}
|
||
}
|
||
}
|
||
}
|
||
|
||
/* Catch underflow that we deferred until after rounding. */
|
||
if (r->exp <= emin2m1)
|
||
goto underflow;
|
||
|
||
/* Clear out trailing garbage. */
|
||
clear_significand_below (r, np2);
|
||
}
|
||
|
||
/* Extend or truncate to a new mode. */
|
||
|
||
void
|
||
real_convert (r, mode, a)
|
||
REAL_VALUE_TYPE *r;
|
||
enum machine_mode mode;
|
||
const REAL_VALUE_TYPE *a;
|
||
{
|
||
const struct real_format *fmt;
|
||
|
||
fmt = real_format_for_mode[mode - QFmode];
|
||
if (fmt == NULL)
|
||
abort ();
|
||
|
||
*r = *a;
|
||
round_for_format (fmt, r);
|
||
|
||
/* round_for_format de-normalizes denormals. Undo just that part. */
|
||
if (r->class == rvc_normal)
|
||
normalize (r);
|
||
}
|
||
|
||
/* Legacy. Likewise, except return the struct directly. */
|
||
|
||
REAL_VALUE_TYPE
|
||
real_value_truncate (mode, a)
|
||
enum machine_mode mode;
|
||
REAL_VALUE_TYPE a;
|
||
{
|
||
REAL_VALUE_TYPE r;
|
||
real_convert (&r, mode, &a);
|
||
return r;
|
||
}
|
||
|
||
/* Return true if truncating to MODE is exact. */
|
||
|
||
bool
|
||
exact_real_truncate (mode, a)
|
||
enum machine_mode mode;
|
||
const REAL_VALUE_TYPE *a;
|
||
{
|
||
REAL_VALUE_TYPE t;
|
||
real_convert (&t, mode, a);
|
||
return real_identical (&t, a);
|
||
}
|
||
|
||
/* Write R to the given target format. Place the words of the result
|
||
in target word order in BUF. There are always 32 bits in each
|
||
long, no matter the size of the host long.
|
||
|
||
Legacy: return word 0 for implementing REAL_VALUE_TO_TARGET_SINGLE. */
|
||
|
||
long
|
||
real_to_target_fmt (buf, r_orig, fmt)
|
||
long *buf;
|
||
const REAL_VALUE_TYPE *r_orig;
|
||
const struct real_format *fmt;
|
||
{
|
||
REAL_VALUE_TYPE r;
|
||
long buf1;
|
||
|
||
r = *r_orig;
|
||
round_for_format (fmt, &r);
|
||
|
||
if (!buf)
|
||
buf = &buf1;
|
||
(*fmt->encode) (fmt, buf, &r);
|
||
|
||
return *buf;
|
||
}
|
||
|
||
/* Similar, but look up the format from MODE. */
|
||
|
||
long
|
||
real_to_target (buf, r, mode)
|
||
long *buf;
|
||
const REAL_VALUE_TYPE *r;
|
||
enum machine_mode mode;
|
||
{
|
||
const struct real_format *fmt;
|
||
|
||
fmt = real_format_for_mode[mode - QFmode];
|
||
if (fmt == NULL)
|
||
abort ();
|
||
|
||
return real_to_target_fmt (buf, r, fmt);
|
||
}
|
||
|
||
/* Read R from the given target format. Read the words of the result
|
||
in target word order in BUF. There are always 32 bits in each
|
||
long, no matter the size of the host long. */
|
||
|
||
void
|
||
real_from_target_fmt (r, buf, fmt)
|
||
REAL_VALUE_TYPE *r;
|
||
const long *buf;
|
||
const struct real_format *fmt;
|
||
{
|
||
(*fmt->decode) (fmt, r, buf);
|
||
}
|
||
|
||
/* Similar, but look up the format from MODE. */
|
||
|
||
void
|
||
real_from_target (r, buf, mode)
|
||
REAL_VALUE_TYPE *r;
|
||
const long *buf;
|
||
enum machine_mode mode;
|
||
{
|
||
const struct real_format *fmt;
|
||
|
||
fmt = real_format_for_mode[mode - QFmode];
|
||
if (fmt == NULL)
|
||
abort ();
|
||
|
||
(*fmt->decode) (fmt, r, buf);
|
||
}
|
||
|
||
/* Return the number of bits in the significand for MODE. */
|
||
/* ??? Legacy. Should get access to real_format directly. */
|
||
|
||
int
|
||
significand_size (mode)
|
||
enum machine_mode mode;
|
||
{
|
||
const struct real_format *fmt;
|
||
|
||
fmt = real_format_for_mode[mode - QFmode];
|
||
if (fmt == NULL)
|
||
return 0;
|
||
|
||
return fmt->p * fmt->log2_b;
|
||
}
|
||
|
||
/* Return a hash value for the given real value. */
|
||
/* ??? The "unsigned int" return value is intended to be hashval_t,
|
||
but I didn't want to pull hashtab.h into real.h. */
|
||
|
||
unsigned int
|
||
real_hash (r)
|
||
const REAL_VALUE_TYPE *r;
|
||
{
|
||
unsigned int h;
|
||
size_t i;
|
||
|
||
h = r->class | (r->sign << 2);
|
||
switch (r->class)
|
||
{
|
||
case rvc_zero:
|
||
case rvc_inf:
|
||
break;
|
||
|
||
case rvc_normal:
|
||
h |= r->exp << 3;
|
||
/* FALLTHRU */
|
||
|
||
case rvc_nan:
|
||
if (sizeof(unsigned long) > sizeof(unsigned int))
|
||
for (i = 0; i < SIGSZ; ++i)
|
||
{
|
||
unsigned long s = r->sig[i];
|
||
h ^= s ^ (s >> (HOST_BITS_PER_LONG / 2));
|
||
}
|
||
else
|
||
for (i = 0; i < SIGSZ; ++i)
|
||
h ^= r->sig[i];
|
||
break;
|
||
|
||
default:
|
||
abort ();
|
||
}
|
||
|
||
return h;
|
||
}
|
||
|
||
/* IEEE single-precision format. */
|
||
|
||
static void encode_ieee_single PARAMS ((const struct real_format *fmt,
|
||
long *, const REAL_VALUE_TYPE *));
|
||
static void decode_ieee_single PARAMS ((const struct real_format *,
|
||
REAL_VALUE_TYPE *, const long *));
|
||
|
||
static void
|
||
encode_ieee_single (fmt, buf, r)
|
||
const struct real_format *fmt;
|
||
long *buf;
|
||
const REAL_VALUE_TYPE *r;
|
||
{
|
||
unsigned long image, sig, exp;
|
||
unsigned long sign = r->sign;
|
||
bool denormal = (r->sig[SIGSZ-1] & SIG_MSB) == 0;
|
||
|
||
image = sign << 31;
|
||
sig = (r->sig[SIGSZ-1] >> (HOST_BITS_PER_LONG - 24)) & 0x7fffff;
|
||
|
||
switch (r->class)
|
||
{
|
||
case rvc_zero:
|
||
break;
|
||
|
||
case rvc_inf:
|
||
if (fmt->has_inf)
|
||
image |= 255 << 23;
|
||
else
|
||
image |= 0x7fffffff;
|
||
break;
|
||
|
||
case rvc_nan:
|
||
if (fmt->has_nans)
|
||
{
|
||
image |= 255 << 23;
|
||
image |= sig;
|
||
if (!fmt->qnan_msb_set)
|
||
image ^= 1 << 23 | 1 << 22;
|
||
}
|
||
else
|
||
image |= 0x7fffffff;
|
||
break;
|
||
|
||
case rvc_normal:
|
||
/* Recall that IEEE numbers are interpreted as 1.F x 2**exp,
|
||
whereas the intermediate representation is 0.F x 2**exp.
|
||
Which means we're off by one. */
|
||
if (denormal)
|
||
exp = 0;
|
||
else
|
||
exp = r->exp + 127 - 1;
|
||
image |= exp << 23;
|
||
image |= sig;
|
||
break;
|
||
|
||
default:
|
||
abort ();
|
||
}
|
||
|
||
buf[0] = image;
|
||
}
|
||
|
||
static void
|
||
decode_ieee_single (fmt, r, buf)
|
||
const struct real_format *fmt;
|
||
REAL_VALUE_TYPE *r;
|
||
const long *buf;
|
||
{
|
||
unsigned long image = buf[0] & 0xffffffff;
|
||
bool sign = (image >> 31) & 1;
|
||
int exp = (image >> 23) & 0xff;
|
||
|
||
memset (r, 0, sizeof (*r));
|
||
image <<= HOST_BITS_PER_LONG - 24;
|
||
image &= ~SIG_MSB;
|
||
|
||
if (exp == 0)
|
||
{
|
||
if (image && fmt->has_denorm)
|
||
{
|
||
r->class = rvc_normal;
|
||
r->sign = sign;
|
||
r->exp = -126;
|
||
r->sig[SIGSZ-1] = image << 1;
|
||
normalize (r);
|
||
}
|
||
else if (fmt->has_signed_zero)
|
||
r->sign = sign;
|
||
}
|
||
else if (exp == 255 && (fmt->has_nans || fmt->has_inf))
|
||
{
|
||
if (image)
|
||
{
|
||
r->class = rvc_nan;
|
||
r->sign = sign;
|
||
if (!fmt->qnan_msb_set)
|
||
image ^= (SIG_MSB >> 1 | SIG_MSB >> 2);
|
||
r->sig[SIGSZ-1] = image;
|
||
}
|
||
else
|
||
{
|
||
r->class = rvc_inf;
|
||
r->sign = sign;
|
||
}
|
||
}
|
||
else
|
||
{
|
||
r->class = rvc_normal;
|
||
r->sign = sign;
|
||
r->exp = exp - 127 + 1;
|
||
r->sig[SIGSZ-1] = image | SIG_MSB;
|
||
}
|
||
}
|
||
|
||
const struct real_format ieee_single_format =
|
||
{
|
||
encode_ieee_single,
|
||
decode_ieee_single,
|
||
2,
|
||
1,
|
||
24,
|
||
-125,
|
||
128,
|
||
true,
|
||
true,
|
||
true,
|
||
true,
|
||
true
|
||
};
|
||
|
||
|
||
/* IEEE double-precision format. */
|
||
|
||
static void encode_ieee_double PARAMS ((const struct real_format *fmt,
|
||
long *, const REAL_VALUE_TYPE *));
|
||
static void decode_ieee_double PARAMS ((const struct real_format *,
|
||
REAL_VALUE_TYPE *, const long *));
|
||
|
||
static void
|
||
encode_ieee_double (fmt, buf, r)
|
||
const struct real_format *fmt;
|
||
long *buf;
|
||
const REAL_VALUE_TYPE *r;
|
||
{
|
||
unsigned long image_lo, image_hi, sig_lo, sig_hi, exp;
|
||
bool denormal = (r->sig[SIGSZ-1] & SIG_MSB) == 0;
|
||
|
||
image_hi = r->sign << 31;
|
||
image_lo = 0;
|
||
|
||
if (HOST_BITS_PER_LONG == 64)
|
||
{
|
||
sig_hi = r->sig[SIGSZ-1];
|
||
sig_lo = (sig_hi >> (64 - 53)) & 0xffffffff;
|
||
sig_hi = (sig_hi >> (64 - 53 + 1) >> 31) & 0xfffff;
|
||
}
|
||
else
|
||
{
|
||
sig_hi = r->sig[SIGSZ-1];
|
||
sig_lo = r->sig[SIGSZ-2];
|
||
sig_lo = (sig_hi << 21) | (sig_lo >> 11);
|
||
sig_hi = (sig_hi >> 11) & 0xfffff;
|
||
}
|
||
|
||
switch (r->class)
|
||
{
|
||
case rvc_zero:
|
||
break;
|
||
|
||
case rvc_inf:
|
||
if (fmt->has_inf)
|
||
image_hi |= 2047 << 20;
|
||
else
|
||
{
|
||
image_hi |= 0x7fffffff;
|
||
image_lo = 0xffffffff;
|
||
}
|
||
break;
|
||
|
||
case rvc_nan:
|
||
if (fmt->has_nans)
|
||
{
|
||
image_hi |= 2047 << 20;
|
||
image_hi |= sig_hi;
|
||
if (!fmt->qnan_msb_set)
|
||
image_hi ^= 1 << 19 | 1 << 18;
|
||
image_lo = sig_lo;
|
||
}
|
||
else
|
||
{
|
||
image_hi |= 0x7fffffff;
|
||
image_lo = 0xffffffff;
|
||
}
|
||
break;
|
||
|
||
case rvc_normal:
|
||
/* Recall that IEEE numbers are interpreted as 1.F x 2**exp,
|
||
whereas the intermediate representation is 0.F x 2**exp.
|
||
Which means we're off by one. */
|
||
if (denormal)
|
||
exp = 0;
|
||
else
|
||
exp = r->exp + 1023 - 1;
|
||
image_hi |= exp << 20;
|
||
image_hi |= sig_hi;
|
||
image_lo = sig_lo;
|
||
break;
|
||
|
||
default:
|
||
abort ();
|
||
}
|
||
|
||
if (FLOAT_WORDS_BIG_ENDIAN)
|
||
buf[0] = image_hi, buf[1] = image_lo;
|
||
else
|
||
buf[0] = image_lo, buf[1] = image_hi;
|
||
}
|
||
|
||
static void
|
||
decode_ieee_double (fmt, r, buf)
|
||
const struct real_format *fmt;
|
||
REAL_VALUE_TYPE *r;
|
||
const long *buf;
|
||
{
|
||
unsigned long image_hi, image_lo;
|
||
bool sign;
|
||
int exp;
|
||
|
||
if (FLOAT_WORDS_BIG_ENDIAN)
|
||
image_hi = buf[0], image_lo = buf[1];
|
||
else
|
||
image_lo = buf[0], image_hi = buf[1];
|
||
image_lo &= 0xffffffff;
|
||
image_hi &= 0xffffffff;
|
||
|
||
sign = (image_hi >> 31) & 1;
|
||
exp = (image_hi >> 20) & 0x7ff;
|
||
|
||
memset (r, 0, sizeof (*r));
|
||
|
||
image_hi <<= 32 - 21;
|
||
image_hi |= image_lo >> 21;
|
||
image_hi &= 0x7fffffff;
|
||
image_lo <<= 32 - 21;
|
||
|
||
if (exp == 0)
|
||
{
|
||
if ((image_hi || image_lo) && fmt->has_denorm)
|
||
{
|
||
r->class = rvc_normal;
|
||
r->sign = sign;
|
||
r->exp = -1022;
|
||
if (HOST_BITS_PER_LONG == 32)
|
||
{
|
||
image_hi = (image_hi << 1) | (image_lo >> 31);
|
||
image_lo <<= 1;
|
||
r->sig[SIGSZ-1] = image_hi;
|
||
r->sig[SIGSZ-2] = image_lo;
|
||
}
|
||
else
|
||
{
|
||
image_hi = (image_hi << 31 << 2) | (image_lo << 1);
|
||
r->sig[SIGSZ-1] = image_hi;
|
||
}
|
||
normalize (r);
|
||
}
|
||
else if (fmt->has_signed_zero)
|
||
r->sign = sign;
|
||
}
|
||
else if (exp == 2047 && (fmt->has_nans || fmt->has_inf))
|
||
{
|
||
if (image_hi || image_lo)
|
||
{
|
||
r->class = rvc_nan;
|
||
r->sign = sign;
|
||
if (HOST_BITS_PER_LONG == 32)
|
||
{
|
||
r->sig[SIGSZ-1] = image_hi;
|
||
r->sig[SIGSZ-2] = image_lo;
|
||
}
|
||
else
|
||
r->sig[SIGSZ-1] = (image_hi << 31 << 1) | image_lo;
|
||
|
||
if (!fmt->qnan_msb_set)
|
||
r->sig[SIGSZ-1] ^= (SIG_MSB >> 1 | SIG_MSB >> 2);
|
||
}
|
||
else
|
||
{
|
||
r->class = rvc_inf;
|
||
r->sign = sign;
|
||
}
|
||
}
|
||
else
|
||
{
|
||
r->class = rvc_normal;
|
||
r->sign = sign;
|
||
r->exp = exp - 1023 + 1;
|
||
if (HOST_BITS_PER_LONG == 32)
|
||
{
|
||
r->sig[SIGSZ-1] = image_hi | SIG_MSB;
|
||
r->sig[SIGSZ-2] = image_lo;
|
||
}
|
||
else
|
||
r->sig[SIGSZ-1] = (image_hi << 31 << 1) | image_lo | SIG_MSB;
|
||
}
|
||
}
|
||
|
||
const struct real_format ieee_double_format =
|
||
{
|
||
encode_ieee_double,
|
||
decode_ieee_double,
|
||
2,
|
||
1,
|
||
53,
|
||
-1021,
|
||
1024,
|
||
true,
|
||
true,
|
||
true,
|
||
true,
|
||
true
|
||
};
|
||
|
||
|
||
/* IEEE extended double precision format. This comes in three
|
||
flavours: Intel's as a 12 byte image, Intel's as a 16 byte image,
|
||
and Motorola's. */
|
||
|
||
static void encode_ieee_extended PARAMS ((const struct real_format *fmt,
|
||
long *, const REAL_VALUE_TYPE *));
|
||
static void decode_ieee_extended PARAMS ((const struct real_format *,
|
||
REAL_VALUE_TYPE *, const long *));
|
||
|
||
static void encode_ieee_extended_128 PARAMS ((const struct real_format *fmt,
|
||
long *,
|
||
const REAL_VALUE_TYPE *));
|
||
static void decode_ieee_extended_128 PARAMS ((const struct real_format *,
|
||
REAL_VALUE_TYPE *,
|
||
const long *));
|
||
|
||
static void
|
||
encode_ieee_extended (fmt, buf, r)
|
||
const struct real_format *fmt;
|
||
long *buf;
|
||
const REAL_VALUE_TYPE *r;
|
||
{
|
||
unsigned long image_hi, sig_hi, sig_lo;
|
||
bool denormal = (r->sig[SIGSZ-1] & SIG_MSB) == 0;
|
||
|
||
image_hi = r->sign << 15;
|
||
sig_hi = sig_lo = 0;
|
||
|
||
switch (r->class)
|
||
{
|
||
case rvc_zero:
|
||
break;
|
||
|
||
case rvc_inf:
|
||
if (fmt->has_inf)
|
||
{
|
||
image_hi |= 32767;
|
||
|
||
/* Intel requires the explicit integer bit to be set, otherwise
|
||
it considers the value a "pseudo-infinity". Motorola docs
|
||
say it doesn't care. */
|
||
sig_hi = 0x80000000;
|
||
}
|
||
else
|
||
{
|
||
image_hi |= 32767;
|
||
sig_lo = sig_hi = 0xffffffff;
|
||
}
|
||
break;
|
||
|
||
case rvc_nan:
|
||
if (fmt->has_nans)
|
||
{
|
||
image_hi |= 32767;
|
||
if (HOST_BITS_PER_LONG == 32)
|
||
{
|
||
sig_hi = r->sig[SIGSZ-1];
|
||
sig_lo = r->sig[SIGSZ-2];
|
||
}
|
||
else
|
||
{
|
||
sig_lo = r->sig[SIGSZ-1];
|
||
sig_hi = sig_lo >> 31 >> 1;
|
||
sig_lo &= 0xffffffff;
|
||
}
|
||
if (!fmt->qnan_msb_set)
|
||
sig_hi ^= 1 << 30 | 1 << 29;
|
||
|
||
/* Intel requires the explicit integer bit to be set, otherwise
|
||
it considers the value a "pseudo-nan". Motorola docs say it
|
||
doesn't care. */
|
||
sig_hi |= 0x80000000;
|
||
}
|
||
else
|
||
{
|
||
image_hi |= 32767;
|
||
sig_lo = sig_hi = 0xffffffff;
|
||
}
|
||
break;
|
||
|
||
case rvc_normal:
|
||
{
|
||
int exp = r->exp;
|
||
|
||
/* Recall that IEEE numbers are interpreted as 1.F x 2**exp,
|
||
whereas the intermediate representation is 0.F x 2**exp.
|
||
Which means we're off by one.
|
||
|
||
Except for Motorola, which consider exp=0 and explicit
|
||
integer bit set to continue to be normalized. In theory
|
||
this descrepency has been taken care of by the difference
|
||
in fmt->emin in round_for_format. */
|
||
|
||
if (denormal)
|
||
exp = 0;
|
||
else
|
||
{
|
||
exp += 16383 - 1;
|
||
if (exp < 0)
|
||
abort ();
|
||
}
|
||
image_hi |= exp;
|
||
|
||
if (HOST_BITS_PER_LONG == 32)
|
||
{
|
||
sig_hi = r->sig[SIGSZ-1];
|
||
sig_lo = r->sig[SIGSZ-2];
|
||
}
|
||
else
|
||
{
|
||
sig_lo = r->sig[SIGSZ-1];
|
||
sig_hi = sig_lo >> 31 >> 1;
|
||
sig_lo &= 0xffffffff;
|
||
}
|
||
}
|
||
break;
|
||
|
||
default:
|
||
abort ();
|
||
}
|
||
|
||
if (FLOAT_WORDS_BIG_ENDIAN)
|
||
buf[0] = image_hi << 16, buf[1] = sig_hi, buf[2] = sig_lo;
|
||
else
|
||
buf[0] = sig_lo, buf[1] = sig_hi, buf[2] = image_hi;
|
||
}
|
||
|
||
static void
|
||
encode_ieee_extended_128 (fmt, buf, r)
|
||
const struct real_format *fmt;
|
||
long *buf;
|
||
const REAL_VALUE_TYPE *r;
|
||
{
|
||
buf[3 * !FLOAT_WORDS_BIG_ENDIAN] = 0;
|
||
encode_ieee_extended (fmt, buf+!!FLOAT_WORDS_BIG_ENDIAN, r);
|
||
}
|
||
|
||
static void
|
||
decode_ieee_extended (fmt, r, buf)
|
||
const struct real_format *fmt;
|
||
REAL_VALUE_TYPE *r;
|
||
const long *buf;
|
||
{
|
||
unsigned long image_hi, sig_hi, sig_lo;
|
||
bool sign;
|
||
int exp;
|
||
|
||
if (FLOAT_WORDS_BIG_ENDIAN)
|
||
image_hi = buf[0] >> 16, sig_hi = buf[1], sig_lo = buf[2];
|
||
else
|
||
sig_lo = buf[0], sig_hi = buf[1], image_hi = buf[2];
|
||
sig_lo &= 0xffffffff;
|
||
sig_hi &= 0xffffffff;
|
||
image_hi &= 0xffffffff;
|
||
|
||
sign = (image_hi >> 15) & 1;
|
||
exp = image_hi & 0x7fff;
|
||
|
||
memset (r, 0, sizeof (*r));
|
||
|
||
if (exp == 0)
|
||
{
|
||
if ((sig_hi || sig_lo) && fmt->has_denorm)
|
||
{
|
||
r->class = rvc_normal;
|
||
r->sign = sign;
|
||
|
||
/* When the IEEE format contains a hidden bit, we know that
|
||
it's zero at this point, and so shift up the significand
|
||
and decrease the exponent to match. In this case, Motorola
|
||
defines the explicit integer bit to be valid, so we don't
|
||
know whether the msb is set or not. */
|
||
r->exp = fmt->emin;
|
||
if (HOST_BITS_PER_LONG == 32)
|
||
{
|
||
r->sig[SIGSZ-1] = sig_hi;
|
||
r->sig[SIGSZ-2] = sig_lo;
|
||
}
|
||
else
|
||
r->sig[SIGSZ-1] = (sig_hi << 31 << 1) | sig_lo;
|
||
|
||
normalize (r);
|
||
}
|
||
else if (fmt->has_signed_zero)
|
||
r->sign = sign;
|
||
}
|
||
else if (exp == 32767 && (fmt->has_nans || fmt->has_inf))
|
||
{
|
||
/* See above re "pseudo-infinities" and "pseudo-nans".
|
||
Short summary is that the MSB will likely always be
|
||
set, and that we don't care about it. */
|
||
sig_hi &= 0x7fffffff;
|
||
|
||
if (sig_hi || sig_lo)
|
||
{
|
||
r->class = rvc_nan;
|
||
r->sign = sign;
|
||
if (HOST_BITS_PER_LONG == 32)
|
||
{
|
||
r->sig[SIGSZ-1] = sig_hi;
|
||
r->sig[SIGSZ-2] = sig_lo;
|
||
}
|
||
else
|
||
r->sig[SIGSZ-1] = (sig_hi << 31 << 1) | sig_lo;
|
||
|
||
if (!fmt->qnan_msb_set)
|
||
r->sig[SIGSZ-1] ^= (SIG_MSB >> 1 | SIG_MSB >> 2);
|
||
}
|
||
else
|
||
{
|
||
r->class = rvc_inf;
|
||
r->sign = sign;
|
||
}
|
||
}
|
||
else
|
||
{
|
||
r->class = rvc_normal;
|
||
r->sign = sign;
|
||
r->exp = exp - 16383 + 1;
|
||
if (HOST_BITS_PER_LONG == 32)
|
||
{
|
||
r->sig[SIGSZ-1] = sig_hi;
|
||
r->sig[SIGSZ-2] = sig_lo;
|
||
}
|
||
else
|
||
r->sig[SIGSZ-1] = (sig_hi << 31 << 1) | sig_lo;
|
||
}
|
||
}
|
||
|
||
static void
|
||
decode_ieee_extended_128 (fmt, r, buf)
|
||
const struct real_format *fmt;
|
||
REAL_VALUE_TYPE *r;
|
||
const long *buf;
|
||
{
|
||
decode_ieee_extended (fmt, r, buf+!!FLOAT_WORDS_BIG_ENDIAN);
|
||
}
|
||
|
||
const struct real_format ieee_extended_motorola_format =
|
||
{
|
||
encode_ieee_extended,
|
||
decode_ieee_extended,
|
||
2,
|
||
1,
|
||
64,
|
||
-16382,
|
||
16384,
|
||
true,
|
||
true,
|
||
true,
|
||
true,
|
||
true
|
||
};
|
||
|
||
const struct real_format ieee_extended_intel_96_format =
|
||
{
|
||
encode_ieee_extended,
|
||
decode_ieee_extended,
|
||
2,
|
||
1,
|
||
64,
|
||
-16381,
|
||
16384,
|
||
true,
|
||
true,
|
||
true,
|
||
true,
|
||
true
|
||
};
|
||
|
||
const struct real_format ieee_extended_intel_128_format =
|
||
{
|
||
encode_ieee_extended_128,
|
||
decode_ieee_extended_128,
|
||
2,
|
||
1,
|
||
64,
|
||
-16381,
|
||
16384,
|
||
true,
|
||
true,
|
||
true,
|
||
true,
|
||
true
|
||
};
|
||
|
||
/* The following caters to i386 systems that set the rounding precision
|
||
to 53 bits instead of 64, e.g. FreeBSD. */
|
||
const struct real_format ieee_extended_intel_96_round_53_format =
|
||
{
|
||
encode_ieee_extended,
|
||
decode_ieee_extended,
|
||
2,
|
||
1,
|
||
53,
|
||
-16381,
|
||
16384,
|
||
true,
|
||
true,
|
||
true,
|
||
true,
|
||
true
|
||
};
|
||
|
||
/* IBM 128-bit extended precision format: a pair of IEEE double precision
|
||
numbers whose sum is equal to the extended precision value. The number
|
||
with greater magnitude is first. This format has the same magnitude
|
||
range as an IEEE double precision value, but effectively 106 bits of
|
||
significand precision. Infinity and NaN are represented by their IEEE
|
||
double precision value stored in the first number, the second number is
|
||
ignored. Zeroes, Infinities, and NaNs are set in both doubles
|
||
due to precedent. */
|
||
|
||
static void encode_ibm_extended PARAMS ((const struct real_format *fmt,
|
||
long *, const REAL_VALUE_TYPE *));
|
||
static void decode_ibm_extended PARAMS ((const struct real_format *,
|
||
REAL_VALUE_TYPE *, const long *));
|
||
|
||
static void
|
||
encode_ibm_extended (fmt, buf, r)
|
||
const struct real_format *fmt ATTRIBUTE_UNUSED;
|
||
long *buf;
|
||
const REAL_VALUE_TYPE *r;
|
||
{
|
||
REAL_VALUE_TYPE u, v;
|
||
|
||
switch (r->class)
|
||
{
|
||
case rvc_zero:
|
||
/* Both doubles have sign bit set. */
|
||
buf[0] = FLOAT_WORDS_BIG_ENDIAN ? r->sign << 31 : 0;
|
||
buf[1] = FLOAT_WORDS_BIG_ENDIAN ? 0 : r->sign << 31;
|
||
buf[2] = buf[0];
|
||
buf[3] = buf[1];
|
||
break;
|
||
|
||
case rvc_inf:
|
||
case rvc_nan:
|
||
/* Both doubles set to Inf / NaN. */
|
||
encode_ieee_double (&ieee_double_format, &buf[0], r);
|
||
buf[2] = buf[0];
|
||
buf[3] = buf[1];
|
||
return;
|
||
|
||
case rvc_normal:
|
||
/* u = IEEE double precision portion of significand. */
|
||
u = *r;
|
||
clear_significand_below (&u, SIGNIFICAND_BITS - 53);
|
||
|
||
normalize (&u);
|
||
/* If the upper double is zero, we have a denormal double, so
|
||
move it to the first double and leave the second as zero. */
|
||
if (u.class == rvc_zero)
|
||
{
|
||
v = u;
|
||
u = *r;
|
||
normalize (&u);
|
||
}
|
||
else
|
||
{
|
||
/* v = remainder containing additional 53 bits of significand. */
|
||
do_add (&v, r, &u, 1);
|
||
round_for_format (&ieee_double_format, &v);
|
||
}
|
||
|
||
round_for_format (&ieee_double_format, &u);
|
||
|
||
encode_ieee_double (&ieee_double_format, &buf[0], &u);
|
||
encode_ieee_double (&ieee_double_format, &buf[2], &v);
|
||
break;
|
||
|
||
default:
|
||
abort ();
|
||
}
|
||
}
|
||
|
||
static void
|
||
decode_ibm_extended (fmt, r, buf)
|
||
const struct real_format *fmt ATTRIBUTE_UNUSED;
|
||
REAL_VALUE_TYPE *r;
|
||
const long *buf;
|
||
{
|
||
REAL_VALUE_TYPE u, v;
|
||
|
||
decode_ieee_double (&ieee_double_format, &u, &buf[0]);
|
||
|
||
if (u.class != rvc_zero && u.class != rvc_inf && u.class != rvc_nan)
|
||
{
|
||
decode_ieee_double (&ieee_double_format, &v, &buf[2]);
|
||
do_add (r, &u, &v, 0);
|
||
}
|
||
else
|
||
*r = u;
|
||
}
|
||
|
||
const struct real_format ibm_extended_format =
|
||
{
|
||
encode_ibm_extended,
|
||
decode_ibm_extended,
|
||
2,
|
||
1,
|
||
53 + 53,
|
||
-1021 + 53,
|
||
1024,
|
||
true,
|
||
true,
|
||
true,
|
||
true,
|
||
true
|
||
};
|
||
|
||
|
||
/* IEEE quad precision format. */
|
||
|
||
static void encode_ieee_quad PARAMS ((const struct real_format *fmt,
|
||
long *, const REAL_VALUE_TYPE *));
|
||
static void decode_ieee_quad PARAMS ((const struct real_format *,
|
||
REAL_VALUE_TYPE *, const long *));
|
||
|
||
static void
|
||
encode_ieee_quad (fmt, buf, r)
|
||
const struct real_format *fmt;
|
||
long *buf;
|
||
const REAL_VALUE_TYPE *r;
|
||
{
|
||
unsigned long image3, image2, image1, image0, exp;
|
||
bool denormal = (r->sig[SIGSZ-1] & SIG_MSB) == 0;
|
||
REAL_VALUE_TYPE u;
|
||
|
||
image3 = r->sign << 31;
|
||
image2 = 0;
|
||
image1 = 0;
|
||
image0 = 0;
|
||
|
||
rshift_significand (&u, r, SIGNIFICAND_BITS - 113);
|
||
|
||
switch (r->class)
|
||
{
|
||
case rvc_zero:
|
||
break;
|
||
|
||
case rvc_inf:
|
||
if (fmt->has_inf)
|
||
image3 |= 32767 << 16;
|
||
else
|
||
{
|
||
image3 |= 0x7fffffff;
|
||
image2 = 0xffffffff;
|
||
image1 = 0xffffffff;
|
||
image0 = 0xffffffff;
|
||
}
|
||
break;
|
||
|
||
case rvc_nan:
|
||
if (fmt->has_nans)
|
||
{
|
||
image3 |= 32767 << 16;
|
||
|
||
if (HOST_BITS_PER_LONG == 32)
|
||
{
|
||
image0 = u.sig[0];
|
||
image1 = u.sig[1];
|
||
image2 = u.sig[2];
|
||
image3 |= u.sig[3] & 0xffff;
|
||
}
|
||
else
|
||
{
|
||
image0 = u.sig[0];
|
||
image1 = image0 >> 31 >> 1;
|
||
image2 = u.sig[1];
|
||
image3 |= (image2 >> 31 >> 1) & 0xffff;
|
||
image0 &= 0xffffffff;
|
||
image2 &= 0xffffffff;
|
||
}
|
||
|
||
if (!fmt->qnan_msb_set)
|
||
image3 ^= 1 << 15 | 1 << 14;
|
||
}
|
||
else
|
||
{
|
||
image3 |= 0x7fffffff;
|
||
image2 = 0xffffffff;
|
||
image1 = 0xffffffff;
|
||
image0 = 0xffffffff;
|
||
}
|
||
break;
|
||
|
||
case rvc_normal:
|
||
/* Recall that IEEE numbers are interpreted as 1.F x 2**exp,
|
||
whereas the intermediate representation is 0.F x 2**exp.
|
||
Which means we're off by one. */
|
||
if (denormal)
|
||
exp = 0;
|
||
else
|
||
exp = r->exp + 16383 - 1;
|
||
image3 |= exp << 16;
|
||
|
||
if (HOST_BITS_PER_LONG == 32)
|
||
{
|
||
image0 = u.sig[0];
|
||
image1 = u.sig[1];
|
||
image2 = u.sig[2];
|
||
image3 |= u.sig[3] & 0xffff;
|
||
}
|
||
else
|
||
{
|
||
image0 = u.sig[0];
|
||
image1 = image0 >> 31 >> 1;
|
||
image2 = u.sig[1];
|
||
image3 |= (image2 >> 31 >> 1) & 0xffff;
|
||
image0 &= 0xffffffff;
|
||
image2 &= 0xffffffff;
|
||
}
|
||
break;
|
||
|
||
default:
|
||
abort ();
|
||
}
|
||
|
||
if (FLOAT_WORDS_BIG_ENDIAN)
|
||
{
|
||
buf[0] = image3;
|
||
buf[1] = image2;
|
||
buf[2] = image1;
|
||
buf[3] = image0;
|
||
}
|
||
else
|
||
{
|
||
buf[0] = image0;
|
||
buf[1] = image1;
|
||
buf[2] = image2;
|
||
buf[3] = image3;
|
||
}
|
||
}
|
||
|
||
static void
|
||
decode_ieee_quad (fmt, r, buf)
|
||
const struct real_format *fmt;
|
||
REAL_VALUE_TYPE *r;
|
||
const long *buf;
|
||
{
|
||
unsigned long image3, image2, image1, image0;
|
||
bool sign;
|
||
int exp;
|
||
|
||
if (FLOAT_WORDS_BIG_ENDIAN)
|
||
{
|
||
image3 = buf[0];
|
||
image2 = buf[1];
|
||
image1 = buf[2];
|
||
image0 = buf[3];
|
||
}
|
||
else
|
||
{
|
||
image0 = buf[0];
|
||
image1 = buf[1];
|
||
image2 = buf[2];
|
||
image3 = buf[3];
|
||
}
|
||
image0 &= 0xffffffff;
|
||
image1 &= 0xffffffff;
|
||
image2 &= 0xffffffff;
|
||
|
||
sign = (image3 >> 31) & 1;
|
||
exp = (image3 >> 16) & 0x7fff;
|
||
image3 &= 0xffff;
|
||
|
||
memset (r, 0, sizeof (*r));
|
||
|
||
if (exp == 0)
|
||
{
|
||
if ((image3 | image2 | image1 | image0) && fmt->has_denorm)
|
||
{
|
||
r->class = rvc_normal;
|
||
r->sign = sign;
|
||
|
||
r->exp = -16382 + (SIGNIFICAND_BITS - 112);
|
||
if (HOST_BITS_PER_LONG == 32)
|
||
{
|
||
r->sig[0] = image0;
|
||
r->sig[1] = image1;
|
||
r->sig[2] = image2;
|
||
r->sig[3] = image3;
|
||
}
|
||
else
|
||
{
|
||
r->sig[0] = (image1 << 31 << 1) | image0;
|
||
r->sig[1] = (image3 << 31 << 1) | image2;
|
||
}
|
||
|
||
normalize (r);
|
||
}
|
||
else if (fmt->has_signed_zero)
|
||
r->sign = sign;
|
||
}
|
||
else if (exp == 32767 && (fmt->has_nans || fmt->has_inf))
|
||
{
|
||
if (image3 | image2 | image1 | image0)
|
||
{
|
||
r->class = rvc_nan;
|
||
r->sign = sign;
|
||
|
||
if (HOST_BITS_PER_LONG == 32)
|
||
{
|
||
r->sig[0] = image0;
|
||
r->sig[1] = image1;
|
||
r->sig[2] = image2;
|
||
r->sig[3] = image3;
|
||
}
|
||
else
|
||
{
|
||
r->sig[0] = (image1 << 31 << 1) | image0;
|
||
r->sig[1] = (image3 << 31 << 1) | image2;
|
||
}
|
||
lshift_significand (r, r, SIGNIFICAND_BITS - 113);
|
||
|
||
if (!fmt->qnan_msb_set)
|
||
r->sig[SIGSZ-1] ^= (SIG_MSB >> 1 | SIG_MSB >> 2);
|
||
}
|
||
else
|
||
{
|
||
r->class = rvc_inf;
|
||
r->sign = sign;
|
||
}
|
||
}
|
||
else
|
||
{
|
||
r->class = rvc_normal;
|
||
r->sign = sign;
|
||
r->exp = exp - 16383 + 1;
|
||
|
||
if (HOST_BITS_PER_LONG == 32)
|
||
{
|
||
r->sig[0] = image0;
|
||
r->sig[1] = image1;
|
||
r->sig[2] = image2;
|
||
r->sig[3] = image3;
|
||
}
|
||
else
|
||
{
|
||
r->sig[0] = (image1 << 31 << 1) | image0;
|
||
r->sig[1] = (image3 << 31 << 1) | image2;
|
||
}
|
||
lshift_significand (r, r, SIGNIFICAND_BITS - 113);
|
||
r->sig[SIGSZ-1] |= SIG_MSB;
|
||
}
|
||
}
|
||
|
||
const struct real_format ieee_quad_format =
|
||
{
|
||
encode_ieee_quad,
|
||
decode_ieee_quad,
|
||
2,
|
||
1,
|
||
113,
|
||
-16381,
|
||
16384,
|
||
true,
|
||
true,
|
||
true,
|
||
true,
|
||
true
|
||
};
|
||
|
||
/* Descriptions of VAX floating point formats can be found beginning at
|
||
|
||
http://www.openvms.compaq.com:8000/73final/4515/4515pro_013.html#f_floating_point_format
|
||
|
||
The thing to remember is that they're almost IEEE, except for word
|
||
order, exponent bias, and the lack of infinities, nans, and denormals.
|
||
|
||
We don't implement the H_floating format here, simply because neither
|
||
the VAX or Alpha ports use it. */
|
||
|
||
static void encode_vax_f PARAMS ((const struct real_format *fmt,
|
||
long *, const REAL_VALUE_TYPE *));
|
||
static void decode_vax_f PARAMS ((const struct real_format *,
|
||
REAL_VALUE_TYPE *, const long *));
|
||
static void encode_vax_d PARAMS ((const struct real_format *fmt,
|
||
long *, const REAL_VALUE_TYPE *));
|
||
static void decode_vax_d PARAMS ((const struct real_format *,
|
||
REAL_VALUE_TYPE *, const long *));
|
||
static void encode_vax_g PARAMS ((const struct real_format *fmt,
|
||
long *, const REAL_VALUE_TYPE *));
|
||
static void decode_vax_g PARAMS ((const struct real_format *,
|
||
REAL_VALUE_TYPE *, const long *));
|
||
|
||
static void
|
||
encode_vax_f (fmt, buf, r)
|
||
const struct real_format *fmt ATTRIBUTE_UNUSED;
|
||
long *buf;
|
||
const REAL_VALUE_TYPE *r;
|
||
{
|
||
unsigned long sign, exp, sig, image;
|
||
|
||
sign = r->sign << 15;
|
||
|
||
switch (r->class)
|
||
{
|
||
case rvc_zero:
|
||
image = 0;
|
||
break;
|
||
|
||
case rvc_inf:
|
||
case rvc_nan:
|
||
image = 0xffff7fff | sign;
|
||
break;
|
||
|
||
case rvc_normal:
|
||
sig = (r->sig[SIGSZ-1] >> (HOST_BITS_PER_LONG - 24)) & 0x7fffff;
|
||
exp = r->exp + 128;
|
||
|
||
image = (sig << 16) & 0xffff0000;
|
||
image |= sign;
|
||
image |= exp << 7;
|
||
image |= sig >> 16;
|
||
break;
|
||
|
||
default:
|
||
abort ();
|
||
}
|
||
|
||
buf[0] = image;
|
||
}
|
||
|
||
static void
|
||
decode_vax_f (fmt, r, buf)
|
||
const struct real_format *fmt ATTRIBUTE_UNUSED;
|
||
REAL_VALUE_TYPE *r;
|
||
const long *buf;
|
||
{
|
||
unsigned long image = buf[0] & 0xffffffff;
|
||
int exp = (image >> 7) & 0xff;
|
||
|
||
memset (r, 0, sizeof (*r));
|
||
|
||
if (exp != 0)
|
||
{
|
||
r->class = rvc_normal;
|
||
r->sign = (image >> 15) & 1;
|
||
r->exp = exp - 128;
|
||
|
||
image = ((image & 0x7f) << 16) | ((image >> 16) & 0xffff);
|
||
r->sig[SIGSZ-1] = (image << (HOST_BITS_PER_LONG - 24)) | SIG_MSB;
|
||
}
|
||
}
|
||
|
||
static void
|
||
encode_vax_d (fmt, buf, r)
|
||
const struct real_format *fmt ATTRIBUTE_UNUSED;
|
||
long *buf;
|
||
const REAL_VALUE_TYPE *r;
|
||
{
|
||
unsigned long image0, image1, sign = r->sign << 15;
|
||
|
||
switch (r->class)
|
||
{
|
||
case rvc_zero:
|
||
image0 = image1 = 0;
|
||
break;
|
||
|
||
case rvc_inf:
|
||
case rvc_nan:
|
||
image0 = 0xffff7fff | sign;
|
||
image1 = 0xffffffff;
|
||
break;
|
||
|
||
case rvc_normal:
|
||
/* Extract the significand into straight hi:lo. */
|
||
if (HOST_BITS_PER_LONG == 64)
|
||
{
|
||
image0 = r->sig[SIGSZ-1];
|
||
image1 = (image0 >> (64 - 56)) & 0xffffffff;
|
||
image0 = (image0 >> (64 - 56 + 1) >> 31) & 0x7fffff;
|
||
}
|
||
else
|
||
{
|
||
image0 = r->sig[SIGSZ-1];
|
||
image1 = r->sig[SIGSZ-2];
|
||
image1 = (image0 << 24) | (image1 >> 8);
|
||
image0 = (image0 >> 8) & 0xffffff;
|
||
}
|
||
|
||
/* Rearrange the half-words of the significand to match the
|
||
external format. */
|
||
image0 = ((image0 << 16) | (image0 >> 16)) & 0xffff007f;
|
||
image1 = ((image1 << 16) | (image1 >> 16)) & 0xffffffff;
|
||
|
||
/* Add the sign and exponent. */
|
||
image0 |= sign;
|
||
image0 |= (r->exp + 128) << 7;
|
||
break;
|
||
|
||
default:
|
||
abort ();
|
||
}
|
||
|
||
if (FLOAT_WORDS_BIG_ENDIAN)
|
||
buf[0] = image1, buf[1] = image0;
|
||
else
|
||
buf[0] = image0, buf[1] = image1;
|
||
}
|
||
|
||
static void
|
||
decode_vax_d (fmt, r, buf)
|
||
const struct real_format *fmt ATTRIBUTE_UNUSED;
|
||
REAL_VALUE_TYPE *r;
|
||
const long *buf;
|
||
{
|
||
unsigned long image0, image1;
|
||
int exp;
|
||
|
||
if (FLOAT_WORDS_BIG_ENDIAN)
|
||
image1 = buf[0], image0 = buf[1];
|
||
else
|
||
image0 = buf[0], image1 = buf[1];
|
||
image0 &= 0xffffffff;
|
||
image1 &= 0xffffffff;
|
||
|
||
exp = (image0 >> 7) & 0x7f;
|
||
|
||
memset (r, 0, sizeof (*r));
|
||
|
||
if (exp != 0)
|
||
{
|
||
r->class = rvc_normal;
|
||
r->sign = (image0 >> 15) & 1;
|
||
r->exp = exp - 128;
|
||
|
||
/* Rearrange the half-words of the external format into
|
||
proper ascending order. */
|
||
image0 = ((image0 & 0x7f) << 16) | ((image0 >> 16) & 0xffff);
|
||
image1 = ((image1 & 0xffff) << 16) | ((image1 >> 16) & 0xffff);
|
||
|
||
if (HOST_BITS_PER_LONG == 64)
|
||
{
|
||
image0 = (image0 << 31 << 1) | image1;
|
||
image0 <<= 64 - 56;
|
||
image0 |= SIG_MSB;
|
||
r->sig[SIGSZ-1] = image0;
|
||
}
|
||
else
|
||
{
|
||
r->sig[SIGSZ-1] = image0;
|
||
r->sig[SIGSZ-2] = image1;
|
||
lshift_significand (r, r, 2*HOST_BITS_PER_LONG - 56);
|
||
r->sig[SIGSZ-1] |= SIG_MSB;
|
||
}
|
||
}
|
||
}
|
||
|
||
static void
|
||
encode_vax_g (fmt, buf, r)
|
||
const struct real_format *fmt ATTRIBUTE_UNUSED;
|
||
long *buf;
|
||
const REAL_VALUE_TYPE *r;
|
||
{
|
||
unsigned long image0, image1, sign = r->sign << 15;
|
||
|
||
switch (r->class)
|
||
{
|
||
case rvc_zero:
|
||
image0 = image1 = 0;
|
||
break;
|
||
|
||
case rvc_inf:
|
||
case rvc_nan:
|
||
image0 = 0xffff7fff | sign;
|
||
image1 = 0xffffffff;
|
||
break;
|
||
|
||
case rvc_normal:
|
||
/* Extract the significand into straight hi:lo. */
|
||
if (HOST_BITS_PER_LONG == 64)
|
||
{
|
||
image0 = r->sig[SIGSZ-1];
|
||
image1 = (image0 >> (64 - 53)) & 0xffffffff;
|
||
image0 = (image0 >> (64 - 53 + 1) >> 31) & 0xfffff;
|
||
}
|
||
else
|
||
{
|
||
image0 = r->sig[SIGSZ-1];
|
||
image1 = r->sig[SIGSZ-2];
|
||
image1 = (image0 << 21) | (image1 >> 11);
|
||
image0 = (image0 >> 11) & 0xfffff;
|
||
}
|
||
|
||
/* Rearrange the half-words of the significand to match the
|
||
external format. */
|
||
image0 = ((image0 << 16) | (image0 >> 16)) & 0xffff000f;
|
||
image1 = ((image1 << 16) | (image1 >> 16)) & 0xffffffff;
|
||
|
||
/* Add the sign and exponent. */
|
||
image0 |= sign;
|
||
image0 |= (r->exp + 1024) << 4;
|
||
break;
|
||
|
||
default:
|
||
abort ();
|
||
}
|
||
|
||
if (FLOAT_WORDS_BIG_ENDIAN)
|
||
buf[0] = image1, buf[1] = image0;
|
||
else
|
||
buf[0] = image0, buf[1] = image1;
|
||
}
|
||
|
||
static void
|
||
decode_vax_g (fmt, r, buf)
|
||
const struct real_format *fmt ATTRIBUTE_UNUSED;
|
||
REAL_VALUE_TYPE *r;
|
||
const long *buf;
|
||
{
|
||
unsigned long image0, image1;
|
||
int exp;
|
||
|
||
if (FLOAT_WORDS_BIG_ENDIAN)
|
||
image1 = buf[0], image0 = buf[1];
|
||
else
|
||
image0 = buf[0], image1 = buf[1];
|
||
image0 &= 0xffffffff;
|
||
image1 &= 0xffffffff;
|
||
|
||
exp = (image0 >> 4) & 0x7ff;
|
||
|
||
memset (r, 0, sizeof (*r));
|
||
|
||
if (exp != 0)
|
||
{
|
||
r->class = rvc_normal;
|
||
r->sign = (image0 >> 15) & 1;
|
||
r->exp = exp - 1024;
|
||
|
||
/* Rearrange the half-words of the external format into
|
||
proper ascending order. */
|
||
image0 = ((image0 & 0xf) << 16) | ((image0 >> 16) & 0xffff);
|
||
image1 = ((image1 & 0xffff) << 16) | ((image1 >> 16) & 0xffff);
|
||
|
||
if (HOST_BITS_PER_LONG == 64)
|
||
{
|
||
image0 = (image0 << 31 << 1) | image1;
|
||
image0 <<= 64 - 53;
|
||
image0 |= SIG_MSB;
|
||
r->sig[SIGSZ-1] = image0;
|
||
}
|
||
else
|
||
{
|
||
r->sig[SIGSZ-1] = image0;
|
||
r->sig[SIGSZ-2] = image1;
|
||
lshift_significand (r, r, 64 - 53);
|
||
r->sig[SIGSZ-1] |= SIG_MSB;
|
||
}
|
||
}
|
||
}
|
||
|
||
const struct real_format vax_f_format =
|
||
{
|
||
encode_vax_f,
|
||
decode_vax_f,
|
||
2,
|
||
1,
|
||
24,
|
||
-127,
|
||
127,
|
||
false,
|
||
false,
|
||
false,
|
||
false,
|
||
false
|
||
};
|
||
|
||
const struct real_format vax_d_format =
|
||
{
|
||
encode_vax_d,
|
||
decode_vax_d,
|
||
2,
|
||
1,
|
||
56,
|
||
-127,
|
||
127,
|
||
false,
|
||
false,
|
||
false,
|
||
false,
|
||
false
|
||
};
|
||
|
||
const struct real_format vax_g_format =
|
||
{
|
||
encode_vax_g,
|
||
decode_vax_g,
|
||
2,
|
||
1,
|
||
53,
|
||
-1023,
|
||
1023,
|
||
false,
|
||
false,
|
||
false,
|
||
false,
|
||
false
|
||
};
|
||
|
||
/* A good reference for these can be found in chapter 9 of
|
||
"ESA/390 Principles of Operation", IBM document number SA22-7201-01.
|
||
An on-line version can be found here:
|
||
|
||
http://publibz.boulder.ibm.com/cgi-bin/bookmgr_OS390/BOOKS/DZ9AR001/9.1?DT=19930923083613
|
||
*/
|
||
|
||
static void encode_i370_single PARAMS ((const struct real_format *fmt,
|
||
long *, const REAL_VALUE_TYPE *));
|
||
static void decode_i370_single PARAMS ((const struct real_format *,
|
||
REAL_VALUE_TYPE *, const long *));
|
||
static void encode_i370_double PARAMS ((const struct real_format *fmt,
|
||
long *, const REAL_VALUE_TYPE *));
|
||
static void decode_i370_double PARAMS ((const struct real_format *,
|
||
REAL_VALUE_TYPE *, const long *));
|
||
|
||
static void
|
||
encode_i370_single (fmt, buf, r)
|
||
const struct real_format *fmt ATTRIBUTE_UNUSED;
|
||
long *buf;
|
||
const REAL_VALUE_TYPE *r;
|
||
{
|
||
unsigned long sign, exp, sig, image;
|
||
|
||
sign = r->sign << 31;
|
||
|
||
switch (r->class)
|
||
{
|
||
case rvc_zero:
|
||
image = 0;
|
||
break;
|
||
|
||
case rvc_inf:
|
||
case rvc_nan:
|
||
image = 0x7fffffff | sign;
|
||
break;
|
||
|
||
case rvc_normal:
|
||
sig = (r->sig[SIGSZ-1] >> (HOST_BITS_PER_LONG - 24)) & 0xffffff;
|
||
exp = ((r->exp / 4) + 64) << 24;
|
||
image = sign | exp | sig;
|
||
break;
|
||
|
||
default:
|
||
abort ();
|
||
}
|
||
|
||
buf[0] = image;
|
||
}
|
||
|
||
static void
|
||
decode_i370_single (fmt, r, buf)
|
||
const struct real_format *fmt ATTRIBUTE_UNUSED;
|
||
REAL_VALUE_TYPE *r;
|
||
const long *buf;
|
||
{
|
||
unsigned long sign, sig, image = buf[0];
|
||
int exp;
|
||
|
||
sign = (image >> 31) & 1;
|
||
exp = (image >> 24) & 0x7f;
|
||
sig = image & 0xffffff;
|
||
|
||
memset (r, 0, sizeof (*r));
|
||
|
||
if (exp || sig)
|
||
{
|
||
r->class = rvc_normal;
|
||
r->sign = sign;
|
||
r->exp = (exp - 64) * 4;
|
||
r->sig[SIGSZ-1] = sig << (HOST_BITS_PER_LONG - 24);
|
||
normalize (r);
|
||
}
|
||
}
|
||
|
||
static void
|
||
encode_i370_double (fmt, buf, r)
|
||
const struct real_format *fmt ATTRIBUTE_UNUSED;
|
||
long *buf;
|
||
const REAL_VALUE_TYPE *r;
|
||
{
|
||
unsigned long sign, exp, image_hi, image_lo;
|
||
|
||
sign = r->sign << 31;
|
||
|
||
switch (r->class)
|
||
{
|
||
case rvc_zero:
|
||
image_hi = image_lo = 0;
|
||
break;
|
||
|
||
case rvc_inf:
|
||
case rvc_nan:
|
||
image_hi = 0x7fffffff | sign;
|
||
image_lo = 0xffffffff;
|
||
break;
|
||
|
||
case rvc_normal:
|
||
if (HOST_BITS_PER_LONG == 64)
|
||
{
|
||
image_hi = r->sig[SIGSZ-1];
|
||
image_lo = (image_hi >> (64 - 56)) & 0xffffffff;
|
||
image_hi = (image_hi >> (64 - 56 + 1) >> 31) & 0xffffff;
|
||
}
|
||
else
|
||
{
|
||
image_hi = r->sig[SIGSZ-1];
|
||
image_lo = r->sig[SIGSZ-2];
|
||
image_lo = (image_lo >> 8) | (image_hi << 24);
|
||
image_hi >>= 8;
|
||
}
|
||
|
||
exp = ((r->exp / 4) + 64) << 24;
|
||
image_hi |= sign | exp;
|
||
break;
|
||
|
||
default:
|
||
abort ();
|
||
}
|
||
|
||
if (FLOAT_WORDS_BIG_ENDIAN)
|
||
buf[0] = image_hi, buf[1] = image_lo;
|
||
else
|
||
buf[0] = image_lo, buf[1] = image_hi;
|
||
}
|
||
|
||
static void
|
||
decode_i370_double (fmt, r, buf)
|
||
const struct real_format *fmt ATTRIBUTE_UNUSED;
|
||
REAL_VALUE_TYPE *r;
|
||
const long *buf;
|
||
{
|
||
unsigned long sign, image_hi, image_lo;
|
||
int exp;
|
||
|
||
if (FLOAT_WORDS_BIG_ENDIAN)
|
||
image_hi = buf[0], image_lo = buf[1];
|
||
else
|
||
image_lo = buf[0], image_hi = buf[1];
|
||
|
||
sign = (image_hi >> 31) & 1;
|
||
exp = (image_hi >> 24) & 0x7f;
|
||
image_hi &= 0xffffff;
|
||
image_lo &= 0xffffffff;
|
||
|
||
memset (r, 0, sizeof (*r));
|
||
|
||
if (exp || image_hi || image_lo)
|
||
{
|
||
r->class = rvc_normal;
|
||
r->sign = sign;
|
||
r->exp = (exp - 64) * 4 + (SIGNIFICAND_BITS - 56);
|
||
|
||
if (HOST_BITS_PER_LONG == 32)
|
||
{
|
||
r->sig[0] = image_lo;
|
||
r->sig[1] = image_hi;
|
||
}
|
||
else
|
||
r->sig[0] = image_lo | (image_hi << 31 << 1);
|
||
|
||
normalize (r);
|
||
}
|
||
}
|
||
|
||
const struct real_format i370_single_format =
|
||
{
|
||
encode_i370_single,
|
||
decode_i370_single,
|
||
16,
|
||
4,
|
||
6,
|
||
-64,
|
||
63,
|
||
false,
|
||
false,
|
||
false, /* ??? The encoding does allow for "unnormals". */
|
||
false, /* ??? The encoding does allow for "unnormals". */
|
||
false
|
||
};
|
||
|
||
const struct real_format i370_double_format =
|
||
{
|
||
encode_i370_double,
|
||
decode_i370_double,
|
||
16,
|
||
4,
|
||
14,
|
||
-64,
|
||
63,
|
||
false,
|
||
false,
|
||
false, /* ??? The encoding does allow for "unnormals". */
|
||
false, /* ??? The encoding does allow for "unnormals". */
|
||
false
|
||
};
|
||
|
||
/* The "twos-complement" c4x format is officially defined as
|
||
|
||
x = s(~s).f * 2**e
|
||
|
||
This is rather misleading. One must remember that F is signed.
|
||
A better description would be
|
||
|
||
x = -1**s * ((s + 1 + .f) * 2**e
|
||
|
||
So if we have a (4 bit) fraction of .1000 with a sign bit of 1,
|
||
that's -1 * (1+1+(-.5)) == -1.5. I think.
|
||
|
||
The constructions here are taken from Tables 5-1 and 5-2 of the
|
||
TMS320C4x User's Guide wherein step-by-step instructions for
|
||
conversion from IEEE are presented. That's close enough to our
|
||
internal representation so as to make things easy.
|
||
|
||
See http://www-s.ti.com/sc/psheets/spru063c/spru063c.pdf */
|
||
|
||
static void encode_c4x_single PARAMS ((const struct real_format *fmt,
|
||
long *, const REAL_VALUE_TYPE *));
|
||
static void decode_c4x_single PARAMS ((const struct real_format *,
|
||
REAL_VALUE_TYPE *, const long *));
|
||
static void encode_c4x_extended PARAMS ((const struct real_format *fmt,
|
||
long *, const REAL_VALUE_TYPE *));
|
||
static void decode_c4x_extended PARAMS ((const struct real_format *,
|
||
REAL_VALUE_TYPE *, const long *));
|
||
|
||
static void
|
||
encode_c4x_single (fmt, buf, r)
|
||
const struct real_format *fmt ATTRIBUTE_UNUSED;
|
||
long *buf;
|
||
const REAL_VALUE_TYPE *r;
|
||
{
|
||
unsigned long image, exp, sig;
|
||
|
||
switch (r->class)
|
||
{
|
||
case rvc_zero:
|
||
exp = -128;
|
||
sig = 0;
|
||
break;
|
||
|
||
case rvc_inf:
|
||
case rvc_nan:
|
||
exp = 127;
|
||
sig = 0x800000 - r->sign;
|
||
break;
|
||
|
||
case rvc_normal:
|
||
exp = r->exp - 1;
|
||
sig = (r->sig[SIGSZ-1] >> (HOST_BITS_PER_LONG - 24)) & 0x7fffff;
|
||
if (r->sign)
|
||
{
|
||
if (sig)
|
||
sig = -sig;
|
||
else
|
||
exp--;
|
||
sig |= 0x800000;
|
||
}
|
||
break;
|
||
|
||
default:
|
||
abort ();
|
||
}
|
||
|
||
image = ((exp & 0xff) << 24) | (sig & 0xffffff);
|
||
buf[0] = image;
|
||
}
|
||
|
||
static void
|
||
decode_c4x_single (fmt, r, buf)
|
||
const struct real_format *fmt ATTRIBUTE_UNUSED;
|
||
REAL_VALUE_TYPE *r;
|
||
const long *buf;
|
||
{
|
||
unsigned long image = buf[0];
|
||
unsigned long sig;
|
||
int exp, sf;
|
||
|
||
exp = (((image >> 24) & 0xff) ^ 0x80) - 0x80;
|
||
sf = ((image & 0xffffff) ^ 0x800000) - 0x800000;
|
||
|
||
memset (r, 0, sizeof (*r));
|
||
|
||
if (exp != -128)
|
||
{
|
||
r->class = rvc_normal;
|
||
|
||
sig = sf & 0x7fffff;
|
||
if (sf < 0)
|
||
{
|
||
r->sign = 1;
|
||
if (sig)
|
||
sig = -sig;
|
||
else
|
||
exp++;
|
||
}
|
||
sig = (sig << (HOST_BITS_PER_LONG - 24)) | SIG_MSB;
|
||
|
||
r->exp = exp + 1;
|
||
r->sig[SIGSZ-1] = sig;
|
||
}
|
||
}
|
||
|
||
static void
|
||
encode_c4x_extended (fmt, buf, r)
|
||
const struct real_format *fmt ATTRIBUTE_UNUSED;
|
||
long *buf;
|
||
const REAL_VALUE_TYPE *r;
|
||
{
|
||
unsigned long exp, sig;
|
||
|
||
switch (r->class)
|
||
{
|
||
case rvc_zero:
|
||
exp = -128;
|
||
sig = 0;
|
||
break;
|
||
|
||
case rvc_inf:
|
||
case rvc_nan:
|
||
exp = 127;
|
||
sig = 0x80000000 - r->sign;
|
||
break;
|
||
|
||
case rvc_normal:
|
||
exp = r->exp - 1;
|
||
|
||
sig = r->sig[SIGSZ-1];
|
||
if (HOST_BITS_PER_LONG == 64)
|
||
sig = sig >> 1 >> 31;
|
||
sig &= 0x7fffffff;
|
||
|
||
if (r->sign)
|
||
{
|
||
if (sig)
|
||
sig = -sig;
|
||
else
|
||
exp--;
|
||
sig |= 0x80000000;
|
||
}
|
||
break;
|
||
|
||
default:
|
||
abort ();
|
||
}
|
||
|
||
exp = (exp & 0xff) << 24;
|
||
sig &= 0xffffffff;
|
||
|
||
if (FLOAT_WORDS_BIG_ENDIAN)
|
||
buf[0] = exp, buf[1] = sig;
|
||
else
|
||
buf[0] = sig, buf[0] = exp;
|
||
}
|
||
|
||
static void
|
||
decode_c4x_extended (fmt, r, buf)
|
||
const struct real_format *fmt ATTRIBUTE_UNUSED;
|
||
REAL_VALUE_TYPE *r;
|
||
const long *buf;
|
||
{
|
||
unsigned long sig;
|
||
int exp, sf;
|
||
|
||
if (FLOAT_WORDS_BIG_ENDIAN)
|
||
exp = buf[0], sf = buf[1];
|
||
else
|
||
sf = buf[0], exp = buf[1];
|
||
|
||
exp = (((exp >> 24) & 0xff) & 0x80) - 0x80;
|
||
sf = ((sf & 0xffffffff) ^ 0x80000000) - 0x80000000;
|
||
|
||
memset (r, 0, sizeof (*r));
|
||
|
||
if (exp != -128)
|
||
{
|
||
r->class = rvc_normal;
|
||
|
||
sig = sf & 0x7fffffff;
|
||
if (sf < 0)
|
||
{
|
||
r->sign = 1;
|
||
if (sig)
|
||
sig = -sig;
|
||
else
|
||
exp++;
|
||
}
|
||
if (HOST_BITS_PER_LONG == 64)
|
||
sig = sig << 1 << 31;
|
||
sig |= SIG_MSB;
|
||
|
||
r->exp = exp + 1;
|
||
r->sig[SIGSZ-1] = sig;
|
||
}
|
||
}
|
||
|
||
const struct real_format c4x_single_format =
|
||
{
|
||
encode_c4x_single,
|
||
decode_c4x_single,
|
||
2,
|
||
1,
|
||
24,
|
||
-126,
|
||
128,
|
||
false,
|
||
false,
|
||
false,
|
||
false,
|
||
false
|
||
};
|
||
|
||
const struct real_format c4x_extended_format =
|
||
{
|
||
encode_c4x_extended,
|
||
decode_c4x_extended,
|
||
2,
|
||
1,
|
||
32,
|
||
-126,
|
||
128,
|
||
false,
|
||
false,
|
||
false,
|
||
false,
|
||
false
|
||
};
|
||
|
||
|
||
/* A synthetic "format" for internal arithmetic. It's the size of the
|
||
internal significand minus the two bits needed for proper rounding.
|
||
The encode and decode routines exist only to satisfy our paranoia
|
||
harness. */
|
||
|
||
static void encode_internal PARAMS ((const struct real_format *fmt,
|
||
long *, const REAL_VALUE_TYPE *));
|
||
static void decode_internal PARAMS ((const struct real_format *,
|
||
REAL_VALUE_TYPE *, const long *));
|
||
|
||
static void
|
||
encode_internal (fmt, buf, r)
|
||
const struct real_format *fmt ATTRIBUTE_UNUSED;
|
||
long *buf;
|
||
const REAL_VALUE_TYPE *r;
|
||
{
|
||
memcpy (buf, r, sizeof (*r));
|
||
}
|
||
|
||
static void
|
||
decode_internal (fmt, r, buf)
|
||
const struct real_format *fmt ATTRIBUTE_UNUSED;
|
||
REAL_VALUE_TYPE *r;
|
||
const long *buf;
|
||
{
|
||
memcpy (r, buf, sizeof (*r));
|
||
}
|
||
|
||
const struct real_format real_internal_format =
|
||
{
|
||
encode_internal,
|
||
decode_internal,
|
||
2,
|
||
1,
|
||
SIGNIFICAND_BITS - 2,
|
||
-MAX_EXP,
|
||
MAX_EXP,
|
||
true,
|
||
true,
|
||
false,
|
||
true,
|
||
true
|
||
};
|
||
|
||
/* Set up default mode to format mapping for IEEE. Everyone else has
|
||
to set these values in OVERRIDE_OPTIONS. */
|
||
|
||
const struct real_format *real_format_for_mode[TFmode - QFmode + 1] =
|
||
{
|
||
NULL, /* QFmode */
|
||
NULL, /* HFmode */
|
||
NULL, /* TQFmode */
|
||
&ieee_single_format, /* SFmode */
|
||
&ieee_double_format, /* DFmode */
|
||
|
||
/* We explicitly don't handle XFmode. There are two formats,
|
||
pretty much equally common. Choose one in OVERRIDE_OPTIONS. */
|
||
NULL, /* XFmode */
|
||
&ieee_quad_format /* TFmode */
|
||
};
|