/* real.c - software floating point emulation.
Copyright (C) 1993, 1994, 1995, 1996, 1997, 1998, 1999,
- 2000, 2002, 2003, 2004, 2005, 2007 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>
return;
case rvc_nan:
/* ??? Print the significand as well, if not canonical? */
- strcpy (str, (r.sign ? "-NaN" : "+NaN"));
+ sprintf (str, "%c%cNaN", (r_orig->sign ? '-' : '+'),
+ (r_orig->signalling ? 'S' : 'Q'));
return;
default:
gcc_unreachable ();
return;
case rvc_nan:
/* ??? Print the significand as well, if not canonical? */
- strcpy (str, (r->sign ? "-NaN" : "+NaN"));
+ sprintf (str, "%c%cNaN", (r->sign ? '-' : '+'),
+ (r->signalling ? 'S' : 'Q'));
return;
default:
gcc_unreachable ();
else if (*str == '+')
str++;
+ if (!strncmp (str, "QNaN", 4))
+ {
+ get_canonical_qnan (r, sign);
+ return 0;
+ }
+ else if (!strncmp (str, "SNaN", 4))
+ {
+ get_canonical_snan (r, sign);
+ return 0;
+ }
+ else if (!strncmp (str, "Inf", 3))
+ {
+ get_inf (r, sign);
+ return 0;
+ }
+
if (str[0] == '0' && (str[1] == 'x' || str[1] == 'X'))
{
/* Hexadecimal floating point. */
do_divide (r, r, &pten);
}
+/* Returns the special REAL_VALUE_TYPE enumerated by E. */
+
+const REAL_VALUE_TYPE *
+get_real_const (enum real_value_const e)
+{
+ static REAL_VALUE_TYPE value[rv_max];
+
+ gcc_assert (e < rv_max);
+
+ /* Initialize mathematical constants for constant folding builtins.
+ These constants need to be given to at least 160 bits precision. */
+ if (value[e].cl == rvc_zero)
+ switch (e)
+ {
+ case rv_e:
+ {
+ mpfr_t m;
+ mpfr_init2 (m, SIGNIFICAND_BITS);
+ mpfr_set_ui (m, 1, GMP_RNDN);
+ mpfr_exp (m, m, GMP_RNDN);
+ real_from_mpfr (&value[e], m, NULL_TREE, GMP_RNDN);
+ mpfr_clear (m);
+ }
+ break;
+ case rv_third:
+ real_arithmetic (&value[e], RDIV_EXPR, &dconst1, real_digit (3));
+ break;
+ case rv_sqrt2:
+ {
+ mpfr_t m;
+ mpfr_init2 (m, SIGNIFICAND_BITS);
+ mpfr_sqrt_ui (m, 2, GMP_RNDN);
+ real_from_mpfr (&value[e], m, NULL_TREE, GMP_RNDN);
+ mpfr_clear (m);
+ }
+ break;
+ default:
+ gcc_unreachable();
+ }
+
+ return &value[e];
+}
+
/* Fills R with +Inf. */
void
SET_REAL_EXP (r, n);
r->sig[SIGSZ-1] = SIG_MSB;
}
-
if (DECIMAL_FLOAT_MODE_P (fmode))
decimal_real_convert (r, fmode, r);
}
base_fmt = fmt->qnan_msb_set ? &ieee_double_format : &mips_double_format;
- /* Renormlize R before doing any arithmetic on it. */
+ /* Renormalize R before doing any arithmetic on it. */
normr = *r;
if (normr.cl == rvc_normal)
normalize (&normr);
decode_decimal128 (fmt, r, buf);
}
-/* Single precision decimal floating point (IEEE 754R). */
+/* Single precision decimal floating point (IEEE 754). */
const struct real_format decimal_single_format =
{
encode_decimal_single,
false
};
-/* Double precision decimal floating point (IEEE 754R). */
+/* Double precision decimal floating point (IEEE 754). */
const struct real_format decimal_double_format =
{
encode_decimal_double,
false
};
-/* Quad precision decimal floating point (IEEE 754R). */
+/* Quad precision decimal floating point (IEEE 754). */
const struct real_format decimal_quad_format =
{
encode_decimal_quad,
false
};
\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,
- 24,
- 24,
- -126,
- 128,
- 23,
- -1,
- false,
- false,
- false,
- false,
- false,
- false
- };
-
-const struct real_format c4x_extended_format =
- {
- encode_c4x_extended,
- decode_c4x_extended,
- 2,
- 32,
- 32,
- -126,
- 128,
- 31,
- -1,
- false,
- false,
- false,
- false,
- false,
- false
- };
-
-\f
/* 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
OSDN Git Service
