/* real.c - software floating point emulation.
Copyright (C) 1993, 1994, 1995, 1996, 1997, 1998, 1999,
- 2000, 2002, 2003, 2004, 2005 Free Software Foundation, Inc.
+ 2000, 2002, 2003, 2004, 2005, 2007, 2008 Free Software Foundation, Inc.
Contributed by Stephen L. Moshier (moshier@world.std.com).
Re-written by Richard Henderson <rth@redhat.com>
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
+ Software Foundation; either version 3, or (at your option) any later
version.
GCC is distributed in the hope that it will be useful, but WITHOUT ANY
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, 51 Franklin Street, Fifth Floor, Boston, MA
- 02110-1301, USA. */
+ along with GCC; see the file COPYING3. If not see
+ <http://www.gnu.org/licenses/>. */
#include "config.h"
#include "system.h"
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. */
+ layout of REAL_VALUE_TYPE we're forced to expand to at least 160 bits. */
/* Used to classify two numbers simultaneously. */
return (r->cl == rvc_nan);
}
+/* Determine whether a floating-point value X is finite. */
+
+bool
+real_isfinite (const REAL_VALUE_TYPE *r)
+{
+ return (r->cl != rvc_nan) && (r->cl != rvc_inf);
+}
+
/* Determine whether a floating-point value X is negative. */
bool
}
/* Initialize R from a decimal or hexadecimal string. The string is
- assumed to have been syntax checked already. */
+ assumed to have been syntax checked already. Return -1 if the
+ value underflows, +1 if overflows, and 0 otherwise. */
-void
+int
real_from_string (REAL_VALUE_TYPE *r, const char *str)
{
int exp = 0;
str++;
}
}
+
+ /* If the mantissa is zero, ignore the exponent. */
+ if (!cmp_significand_0 (r))
+ goto is_a_zero;
+
if (*str == 'p' || *str == 'P')
{
bool exp_neg = false;
}
}
+ /* If the mantissa is zero, ignore the exponent. */
+ if (r->cl == rvc_zero)
+ goto is_a_zero;
+
if (*str == 'e' || *str == 'E')
{
bool exp_neg = false;
}
r->sign = sign;
- return;
+ return 0;
+
+ is_a_zero:
+ get_zero (r, sign);
+ return 0;
underflow:
get_zero (r, sign);
- return;
+ return -1;
overflow:
get_inf (r, sign);
- return;
+ return 1;
}
/* Legacy. Similar, but return the result directly. */
str++;
if (*str == '0')
{
- if (*++str == 'x')
- str++, base = 16;
+ str++;
+ if (*str == 'x' || *str == 'X')
+ {
+ base = 16;
+ str++;
+ }
else
base = 8;
}
{
r->cl = rvc_normal;
r->sign = sign;
- SET_REAL_EXP (r, fmt->emax * fmt->log2_b);
+ SET_REAL_EXP (r, fmt->emax);
- np2 = SIGNIFICAND_BITS - fmt->p * fmt->log2_b;
+ np2 = SIGNIFICAND_BITS - fmt->p;
memset (r->sig, -1, SIGSZ * sizeof (unsigned long));
clear_significand_below (r, np2);
+
+ if (fmt->pnan < fmt->p)
+ /* This is an IBM extended double format made up of two IEEE
+ doubles. The value of the long double is the sum of the
+ values of the two parts. The most significant part is
+ required to be the value of the long double rounded to the
+ nearest double. Rounding means we need a slightly smaller
+ value for LDBL_MAX. */
+ clear_significand_bit (r, SIGNIFICAND_BITS - fmt->pnan);
}
}
/* Fills R with 2**N. */
void
-real_2expN (REAL_VALUE_TYPE *r, int n)
+real_2expN (REAL_VALUE_TYPE *r, int n, enum machine_mode fmode)
{
memset (r, 0, sizeof (*r));
SET_REAL_EXP (r, n);
r->sig[SIGSZ-1] = SIG_MSB;
}
+ if (DECIMAL_FLOAT_MODE_P (fmode))
+ decimal_real_convert (r, fmode, r);
}
\f
decimal_real_convert (r, DFmode, r);
}
- p2 = fmt->p * fmt->log2_b;
- emin2m1 = (fmt->emin - 1) * fmt->log2_b;
- emax2 = fmt->emax * fmt->log2_b;
+ p2 = fmt->p;
+ emin2m1 = fmt->emin - 1;
+ emax2 = fmt->emax;
np2 = SIGNIFICAND_BITS - p2;
switch (r->cl)
gcc_unreachable ();
}
- /* If we're not base2, normalize the exponent to a multiple of
- the true base. */
- if (fmt->log2_b != 1)
- {
- int shift;
-
- gcc_assert (fmt->b != 10);
- shift = REAL_EXP (r) & (fmt->log2_b - 1);
- if (shift)
- {
- shift = fmt->log2_b - shift;
- r->sig[0] |= sticky_rshift_significand (r, r, shift);
- SET_REAL_EXP (r, REAL_EXP (r) + shift);
- }
- }
-
/* Check the range of the exponent. If we're out of range,
either underflow or overflow. */
if (REAL_EXP (r) > emax2)
if (REAL_EXP (r) > emax2)
goto overflow;
r->sig[SIGSZ-1] = SIG_MSB;
-
- if (fmt->log2_b != 1)
- {
- int shift = REAL_EXP (r) & (fmt->log2_b - 1);
- if (shift)
- {
- shift = fmt->log2_b - shift;
- rshift_significand (r, r, shift);
- SET_REAL_EXP (r, REAL_EXP (r) + shift);
- if (REAL_EXP (r) > emax2)
- goto overflow;
- }
- }
}
}
gcc_assert (fmt);
/* Don't allow conversion to denormals. */
- emin2m1 = (fmt->emin - 1) * fmt->log2_b;
+ emin2m1 = fmt->emin - 1;
if (REAL_EXP (a) <= emin2m1)
return false;
double log2_10 = 3.3219281;
return fmt->p * log2_10;
}
- return fmt->p * fmt->log2_b;
+ return fmt->p;
}
/* Return a hash value for the given real value. */
if (fmt->has_nans)
{
if (r->canonical)
- sig = 0;
+ sig = (fmt->canonical_nan_lsbs_set ? (1 << 22) - 1 : 0);
if (r->signalling == fmt->qnan_msb_set)
sig &= ~(1 << 22);
else
sig |= 1 << 22;
- /* We overload qnan_msb_set here: it's only clear for
- mips_ieee_single, which wants all mantissa bits but the
- quiet/signalling one set in canonical NaNs (at least
- Quiet ones). */
- if (r->canonical && !fmt->qnan_msb_set)
- sig |= (1 << 22) - 1;
- else if (sig == 0)
+ if (sig == 0)
sig = 1 << 21;
image |= 255 << 23;
encode_ieee_single,
decode_ieee_single,
2,
- 1,
24,
24,
-125,
true,
true,
true,
- true
+ true,
+ false
};
const struct real_format mips_single_format =
encode_ieee_single,
decode_ieee_single,
2,
- 1,
24,
24,
-125,
true,
true,
true,
- false
+ false,
+ true
};
+const struct real_format motorola_single_format =
+ {
+ encode_ieee_single,
+ decode_ieee_single,
+ 2,
+ 24,
+ 24,
+ -125,
+ 128,
+ 31,
+ 31,
+ true,
+ true,
+ true,
+ true,
+ true,
+ true
+ };
\f
/* IEEE double-precision format. */
if (fmt->has_nans)
{
if (r->canonical)
- sig_hi = sig_lo = 0;
+ {
+ if (fmt->canonical_nan_lsbs_set)
+ {
+ sig_hi = (1 << 19) - 1;
+ sig_lo = 0xffffffff;
+ }
+ else
+ {
+ sig_hi = 0;
+ sig_lo = 0;
+ }
+ }
if (r->signalling == fmt->qnan_msb_set)
sig_hi &= ~(1 << 19);
else
sig_hi |= 1 << 19;
- /* We overload qnan_msb_set here: it's only clear for
- mips_ieee_single, which wants all mantissa bits but the
- quiet/signalling one set in canonical NaNs (at least
- Quiet ones). */
- if (r->canonical && !fmt->qnan_msb_set)
- {
- sig_hi |= (1 << 19) - 1;
- sig_lo = 0xffffffff;
- }
- else if (sig_hi == 0 && sig_lo == 0)
+ if (sig_hi == 0 && sig_lo == 0)
sig_hi = 1 << 18;
image_hi |= 2047 << 20;
encode_ieee_double,
decode_ieee_double,
2,
- 1,
53,
53,
-1021,
true,
true,
true,
- true
+ true,
+ false
};
const struct real_format mips_double_format =
encode_ieee_double,
decode_ieee_double,
2,
- 1,
53,
53,
-1021,
true,
true,
true,
- false
+ false,
+ true
};
+const struct real_format motorola_double_format =
+ {
+ encode_ieee_double,
+ decode_ieee_double,
+ 2,
+ 53,
+ 53,
+ -1021,
+ 1024,
+ 63,
+ 63,
+ true,
+ true,
+ true,
+ true,
+ true,
+ true
+ };
\f
/* IEEE extended real format. This comes in three flavors: Intel's as
a 12 byte image, Intel's as a 16 byte image, and Motorola's. Intel
if (fmt->has_nans)
{
image_hi |= 32767;
- if (HOST_BITS_PER_LONG == 32)
+ if (r->canonical)
+ {
+ if (fmt->canonical_nan_lsbs_set)
+ {
+ sig_hi = (1 << 30) - 1;
+ sig_lo = 0xffffffff;
+ }
+ }
+ else if (HOST_BITS_PER_LONG == 32)
{
sig_hi = r->sig[SIGSZ-1];
sig_lo = r->sig[SIGSZ-2];
encode_ieee_extended_motorola,
decode_ieee_extended_motorola,
2,
- 1,
64,
64,
-16382,
true,
true,
true,
+ true,
true
};
encode_ieee_extended_intel_96,
decode_ieee_extended_intel_96,
2,
- 1,
64,
64,
-16381,
true,
true,
true,
- true
+ true,
+ false
};
const struct real_format ieee_extended_intel_128_format =
encode_ieee_extended_intel_128,
decode_ieee_extended_intel_128,
2,
- 1,
64,
64,
-16381,
true,
true,
true,
- true
+ true,
+ false
};
/* The following caters to i386 systems that set the rounding precision
encode_ieee_extended_intel_96,
decode_ieee_extended_intel_96,
2,
- 1,
53,
53,
-16381,
true,
true,
true,
- true
+ true,
+ false
};
\f
/* IBM 128-bit extended precision format: a pair of IEEE double precision
encode_ibm_extended,
decode_ibm_extended,
2,
- 1,
53 + 53,
53,
-1021 + 53,
true,
true,
true,
- true
+ true,
+ false
};
const struct real_format mips_extended_format =
encode_ibm_extended,
decode_ibm_extended,
2,
- 1,
53 + 53,
53,
-1021 + 53,
true,
true,
true,
- false
+ false,
+ true
};
\f
if (r->canonical)
{
- /* Don't use bits from the significand. The
- initialization above is right. */
+ if (fmt->canonical_nan_lsbs_set)
+ {
+ image3 |= 0x7fff;
+ image2 = image1 = image0 = 0xffffffff;
+ }
}
else if (HOST_BITS_PER_LONG == 32)
{
image3 &= ~0x8000;
else
image3 |= 0x8000;
- /* We overload qnan_msb_set here: it's only clear for
- mips_ieee_single, which wants all mantissa bits but the
- quiet/signalling one set in canonical NaNs (at least
- Quiet ones). */
- if (r->canonical && !fmt->qnan_msb_set)
- {
- image3 |= 0x7fff;
- image2 = image1 = image0 = 0xffffffff;
- }
- else if (((image3 & 0xffff) | image2 | image1 | image0) == 0)
+ if (((image3 & 0xffff) | image2 | image1 | image0) == 0)
image3 |= 0x4000;
}
else
encode_ieee_quad,
decode_ieee_quad,
2,
- 1,
113,
113,
-16381,
true,
true,
true,
- true
+ true,
+ false
};
const struct real_format mips_quad_format =
encode_ieee_quad,
decode_ieee_quad,
2,
- 1,
113,
113,
-16381,
true,
true,
true,
- false
+ false,
+ true
};
\f
/* Descriptions of VAX floating point formats can be found beginning at
encode_vax_f,
decode_vax_f,
2,
- 1,
24,
24,
-127,
false,
false,
false,
+ false,
false
};
encode_vax_d,
decode_vax_d,
2,
- 1,
56,
56,
-127,
false,
false,
false,
+ false,
false
};
encode_vax_g,
decode_vax_g,
2,
- 1,
53,
53,
-1023,
false,
false,
false,
- false
- };
-\f
-/* 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 (const struct real_format *fmt,
- long *, const REAL_VALUE_TYPE *);
-static void decode_i370_single (const struct real_format *,
- REAL_VALUE_TYPE *, const long *);
-static void encode_i370_double (const struct real_format *fmt,
- long *, const REAL_VALUE_TYPE *);
-static void decode_i370_double (const struct real_format *,
- REAL_VALUE_TYPE *, const long *);
-
-static void
-encode_i370_single (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->cl)
- {
- 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 = ((REAL_EXP (r) / 4) + 64) << 24;
- image = sign | exp | sig;
- break;
-
- default:
- gcc_unreachable ();
- }
-
- buf[0] = image;
-}
-
-static void
-decode_i370_single (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->cl = rvc_normal;
- r->sign = sign;
- SET_REAL_EXP (r, (exp - 64) * 4);
- r->sig[SIGSZ-1] = sig << (HOST_BITS_PER_LONG - 24);
- normalize (r);
- }
-}
-
-static void
-encode_i370_double (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->cl)
- {
- 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 = ((REAL_EXP (r) / 4) + 64) << 24;
- image_hi |= sign | exp;
- break;
-
- default:
- gcc_unreachable ();
- }
-
- 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 (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->cl = rvc_normal;
- r->sign = sign;
- SET_REAL_EXP (r, (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,
- 6,
- -64,
- 63,
- 31,
- 31,
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,
- 14,
- -64,
- 63,
- 63,
- 63,
- false,
- false,
- false, /* ??? The encoding does allow for "unnormals". */
- false, /* ??? The encoding does allow for "unnormals". */
false
};
\f
encode_decimal_single,
decode_decimal_single,
10,
- 1, /* log10 */
7,
7,
-95,
true,
true,
true,
- true
+ true,
+ false
};
/* Double precision decimal floating point (IEEE 754R). */
encode_decimal_double,
decode_decimal_double,
10,
- 1, /* log10 */
16,
16,
-383,
true,
true,
true,
- true
+ true,
+ false
};
/* Quad precision decimal floating point (IEEE 754R). */
encode_decimal_quad,
decode_decimal_quad,
10,
- 1, /* log10 */
34,
34,
-6143,
true,
true,
true,
- true
- };
-\f
-/* 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 (const struct real_format *fmt,
- long *, const REAL_VALUE_TYPE *);
-static void decode_c4x_single (const struct real_format *,
- REAL_VALUE_TYPE *, const long *);
-static void encode_c4x_extended (const struct real_format *fmt,
- long *, const REAL_VALUE_TYPE *);
-static void decode_c4x_extended (const struct real_format *,
- REAL_VALUE_TYPE *, const long *);
-
-static void
-encode_c4x_single (const struct real_format *fmt ATTRIBUTE_UNUSED,
- long *buf, const REAL_VALUE_TYPE *r)
-{
- unsigned long image, exp, sig;
-
- switch (r->cl)
- {
- 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 = REAL_EXP (r) - 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:
- gcc_unreachable ();
- }
-
- image = ((exp & 0xff) << 24) | (sig & 0xffffff);
- buf[0] = image;
-}
-
-static void
-decode_c4x_single (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->cl = 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;
-
- SET_REAL_EXP (r, exp + 1);
- r->sig[SIGSZ-1] = sig;
- }
-}
-
-static void
-encode_c4x_extended (const struct real_format *fmt ATTRIBUTE_UNUSED,
- long *buf, const REAL_VALUE_TYPE *r)
-{
- unsigned long exp, sig;
-
- switch (r->cl)
- {
- 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 = REAL_EXP (r) - 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:
- gcc_unreachable ();
- }
-
- 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 (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->cl = 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;
-
- SET_REAL_EXP (r, exp + 1);
- r->sig[SIGSZ-1] = sig;
- }
-}
-
-const struct real_format c4x_single_format =
- {
- encode_c4x_single,
- decode_c4x_single,
- 2,
- 1,
- 24,
- 24,
- -126,
- 128,
- 23,
- -1,
- false,
- false,
- false,
- false,
- false
- };
-
-const struct real_format c4x_extended_format =
- {
- encode_c4x_extended,
- decode_c4x_extended,
- 2,
- 1,
- 32,
- 32,
- -126,
- 128,
- 31,
- -1,
- false,
- false,
- false,
- false,
+ true,
false
};
-
\f
/* A synthetic "format" for internal arithmetic. It's the size of the
internal significand minus the two bits needed for proper rounding.
encode_internal,
decode_internal,
2,
- 1,
SIGNIFICAND_BITS - 2,
SIGNIFICAND_BITS - 2,
-MAX_EXP,
true,
false,
true,
- true
+ true,
+ false
};
\f
/* Calculate the square root of X in mode MODE, and store the result
}
/* Infinity and NaN return themselves. */
- if (real_isinf (x) || real_isnan (x))
+ if (!real_isfinite (x))
{
*r = *x;
return false;
r->sign = x->sign;
}
+/* Convert from REAL_VALUE_TYPE to MPFR. The caller is responsible
+ for initializing and clearing the MPFR parameter. */
+
+void
+mpfr_from_real (mpfr_ptr m, const REAL_VALUE_TYPE *r, mp_rnd_t rndmode)
+{
+ /* We use a string as an intermediate type. */
+ char buf[128];
+ int ret;
+
+ /* Take care of Infinity and NaN. */
+ if (r->cl == rvc_inf)
+ {
+ mpfr_set_inf (m, r->sign == 1 ? -1 : 1);
+ return;
+ }
+
+ if (r->cl == rvc_nan)
+ {
+ mpfr_set_nan (m);
+ return;
+ }
+
+ real_to_hexadecimal (buf, r, sizeof (buf), 0, 1);
+ /* mpfr_set_str() parses hexadecimal floats from strings in the same
+ format that GCC will output them. Nothing extra is needed. */
+ ret = mpfr_set_str (m, buf, 16, rndmode);
+ gcc_assert (ret == 0);
+}
+
+/* Convert from MPFR to REAL_VALUE_TYPE, for a given type TYPE and rounding
+ mode RNDMODE. TYPE is only relevant if M is a NaN. */
+
+void
+real_from_mpfr (REAL_VALUE_TYPE *r, mpfr_srcptr m, tree type, mp_rnd_t rndmode)
+{
+ /* We use a string as an intermediate type. */
+ char buf[128], *rstr;
+ mp_exp_t exp;
+
+ /* Take care of Infinity and NaN. */
+ if (mpfr_inf_p (m))
+ {
+ real_inf (r);
+ if (mpfr_sgn (m) < 0)
+ *r = REAL_VALUE_NEGATE (*r);
+ return;
+ }
+
+ if (mpfr_nan_p (m))
+ {
+ real_nan (r, "", 1, TYPE_MODE (type));
+ return;
+ }
+
+ rstr = mpfr_get_str (NULL, &exp, 16, 0, m, rndmode);
+
+ /* The additional 12 chars add space for the sprintf below. This
+ leaves 6 digits for the exponent which is supposedly enough. */
+ gcc_assert (rstr != NULL && strlen (rstr) < sizeof (buf) - 12);
+
+ /* REAL_VALUE_ATOF expects the exponent for mantissa * 2**exp,
+ mpfr_get_str returns the exponent for mantissa * 16**exp, adjust
+ for that. */
+ exp *= 4;
+
+ if (rstr[0] == '-')
+ sprintf (buf, "-0x.%sp%d", &rstr[1], (int) exp);
+ else
+ sprintf (buf, "0x.%sp%d", rstr, (int) exp);
+
+ mpfr_free_str (rstr);
+
+ real_from_string (r, buf);
+}
+
+/* Check whether the real constant value given is an integer. */
+
+bool
+real_isinteger (const REAL_VALUE_TYPE *c, enum machine_mode mode)
+{
+ REAL_VALUE_TYPE cint;
+
+ real_trunc (&cint, mode, c);
+ return real_identical (c, &cint);
+}
+
+/* Write into BUF the maximum representable finite floating-point
+ number, (1 - b**-p) * b**emax for a given FP format FMT as a hex
+ float string. LEN is the size of BUF, and the buffer must be large
+ enough to contain the resulting string. */
+
+void
+get_max_float (const struct real_format *fmt, char *buf, size_t len)
+{
+ int i, n;
+ char *p;
+
+ strcpy (buf, "0x0.");
+ n = fmt->p;
+ for (i = 0, p = buf + 4; i + 3 < n; i += 4)
+ *p++ = 'f';
+ if (i < n)
+ *p++ = "08ce"[n - i];
+ sprintf (p, "p%d", fmt->emax);
+ if (fmt->pnan < fmt->p)
+ {
+ /* This is an IBM extended double format made up of two IEEE
+ doubles. The value of the long double is the sum of the
+ values of the two parts. The most significant part is
+ required to be the value of the long double rounded to the
+ nearest double. Rounding means we need a slightly smaller
+ value for LDBL_MAX. */
+ buf[4 + fmt->pnan / 4] = "7bde"[fmt->pnan % 4];
+ }
+
+ gcc_assert (strlen (buf) < len);
+}
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