+2013-11-16 Alan Modra <amodra@gmail.com>
+
+ [BZ #5268]
+ * include/gmp.h (__mpn_extract_double, __mpn_extract_long_double):
+ Update prototypes.
+ * stdio-common/printf_fp.c: Likewise.
+ (__printf_fp): Use returned zero_bits.
+ * stdlib/dbl2mpn.c (__mpn_extract_double): Update funtion arguments.
+ * sysdeps/i386/ldbl2mpn.c (__mpn_extract_long_double): Don't perform
+ shifts for denormals here. Instead return leading zero bit count
+ and adjust return value of function.
+ * sysdeps/ieee754/dbl-64/dbl2mpn.c (__mpn_extract_long_double): Likewise.
+ * sysdeps/ieee754/ldbl-128/ldbl2mpn.c (__mpn_extract_long_double):
+ Likewise.
+ * sysdeps/ieee754/ldbl-96/ldbl2mpn.c (__mpn_extract_long_double):
+ Likewise.
+ * sysdeps/ieee754/ldbl-128ibm/ldbl2mpn.c (__mpn_extract_long_double):
+ Likewise. Return an extra 11 bits of precision.
+
2013-11-16 Alan Modra <amodra@gmail.com>
* Makerules (abilist): Define and use var in abilist rules.
/* Now define the internal interfaces. */
extern mp_size_t __mpn_extract_double (mp_ptr res_ptr, mp_size_t size,
- int *expt, int *is_neg,
- double value);
+ int *expt, int *zero_bits,
+ int *is_neg, double value);
extern mp_size_t __mpn_extract_long_double (mp_ptr res_ptr, mp_size_t size,
- int *expt, int *is_neg,
- long double value);
+ int *expt, int *zero_bits,
+ int *is_neg, long double value);
extern float __mpn_construct_float (mp_srcptr frac_ptr, int expt, int sign);
(u##size > v##size || (u##size == v##size && __mpn_cmp (u, v, u##size) >= 0))
extern mp_size_t __mpn_extract_double (mp_ptr res_ptr, mp_size_t size,
- int *expt, int *is_neg,
- double value);
+ int *expt, int *zero_bits,
+ int *is_neg, double value);
extern mp_size_t __mpn_extract_long_double (mp_ptr res_ptr, mp_size_t size,
- int *expt, int *is_neg,
- long double value);
+ int *expt, int *zero_bits,
+ int *is_neg, long double value);
extern unsigned int __guess_grouping (unsigned int intdig_max,
const char *grouping);
}
else
{
+ int zero_bits;
fracsize = __mpn_extract_long_double (fp_input,
(sizeof (fp_input) /
sizeof (fp_input[0])),
- &exponent, &is_neg,
+ &exponent, &zero_bits, &is_neg,
fpnum.ldbl);
- to_shift = 1 + fracsize * BITS_PER_MP_LIMB - LDBL_MANT_DIG;
+ to_shift = 1 + zero_bits;
}
}
else
}
else
{
+ int zero_bits;
fracsize = __mpn_extract_double (fp_input,
(sizeof (fp_input)
/ sizeof (fp_input[0])),
- &exponent, &is_neg, fpnum.dbl);
- to_shift = 1 + fracsize * BITS_PER_MP_LIMB - DBL_MANT_DIG;
+ &exponent, &zero_bits, &is_neg,
+ fpnum.dbl);
+ to_shift = 1 + zero_bits;
}
}
mp_size_t
__mpn_extract_double (mp_ptr res_ptr, mp_size_t size,
- int *expt, int *is_neg,
+ int *expt, int *zero_bits, int *is_neg,
double value)
{
#error "__mpn_extract_double is not implemented for this floating point format"
mp_size_t
__mpn_extract_long_double (mp_ptr res_ptr, mp_size_t size,
- int *expt, int *is_neg,
+ int *expt, int *zero_bits, int *is_neg,
long double value)
{
union ieee854_long_double u;
#error "mp_limb size " BITS_PER_MP_LIMB "not accounted for"
#endif
+/* The format does not fill the last limb. There are some zeros. */
+#define NUM_LEADING_ZEROS (N * BITS_PER_MP_LIMB - LDBL_MANT_DIG)
+ *zero_bits = NUM_LEADING_ZEROS;
+
if (u.ieee.exponent == 0)
{
/* A biased exponent of zero is a special case.
Either it is a zero or it is a denormal number. */
if (res_ptr[0] == 0 && res_ptr[N - 1] == 0) /* Assumes N<=2. */
- /* It's zero. */
- *expt = 0;
+ {
+ /* It's zero. */
+ *expt = 0;
+ return 1;
+ }
else
{
/* It is a denormal number, meaning it has no implicit leading
one bit, and its exponent is in fact the format minimum. */
int cnt;
+ int exp = 1 - IEEE854_LONG_DOUBLE_BIAS;
/* One problem with Intel's 80-bit format is that the explicit
leading one in the normalized representation has to be zero
if (res_ptr[N - 1] != 0)
{
count_leading_zeros (cnt, res_ptr[N - 1]);
- if (cnt != 0)
- {
-#if N == 2
- res_ptr[N - 1] = res_ptr[N - 1] << cnt
- | (res_ptr[0] >> (BITS_PER_MP_LIMB - cnt));
- res_ptr[0] <<= cnt;
-#else
- res_ptr[N - 1] <<= cnt;
-#endif
- }
- *expt = LDBL_MIN_EXP - 1 - cnt;
+ *zero_bits = cnt;
+ *expt = exp + NUM_LEADING_ZEROS - cnt;
+ return N;
}
else if (res_ptr[0] != 0)
{
count_leading_zeros (cnt, res_ptr[0]);
- res_ptr[N - 1] = res_ptr[0] << cnt;
- res_ptr[0] = 0;
- *expt = LDBL_MIN_EXP - 1 - BITS_PER_MP_LIMB - cnt;
+ exp -= BITS_PER_MP_LIMB;
+ *zero_bits = cnt;
+ *expt = exp + NUM_LEADING_ZEROS - cnt;
+ return 1;
}
else
{
#else
res_ptr[0] = 0x8000000000000000ul;
#endif
- *expt = LDBL_MIN_EXP - 1;
+ *expt = 1 - IEEE854_LONG_DOUBLE_BIAS;
}
}
}
mp_size_t
__mpn_extract_double (mp_ptr res_ptr, mp_size_t size,
- int *expt, int *is_neg,
+ int *expt, int *zero_bits, int *is_neg,
double value)
{
union ieee754_double u;
#else
#error "mp_limb size " BITS_PER_MP_LIMB "not accounted for"
#endif
+
/* The format does not fill the last limb. There are some zeros. */
-#define NUM_LEADING_ZEROS (BITS_PER_MP_LIMB \
- - (DBL_MANT_DIG - ((N - 1) * BITS_PER_MP_LIMB)))
+#define NUM_LEADING_ZEROS (N * BITS_PER_MP_LIMB - DBL_MANT_DIG)
+ *zero_bits = NUM_LEADING_ZEROS;
if (u.ieee.exponent == 0)
{
/* It is a denormal number, meaning it has no implicit leading
one bit, and its exponent is in fact the format minimum. */
int cnt;
+ int exp = 1 - IEEE754_DOUBLE_BIAS;
+ int n = N;
if (res_ptr[N - 1] != 0)
- {
- count_leading_zeros (cnt, res_ptr[N - 1]);
- cnt -= NUM_LEADING_ZEROS;
-#if N == 2
- res_ptr[N - 1] = res_ptr[1] << cnt
- | (N - 1)
- * (res_ptr[0] >> (BITS_PER_MP_LIMB - cnt));
- res_ptr[0] <<= cnt;
-#else
- res_ptr[N - 1] <<= cnt;
-#endif
- *expt = DBL_MIN_EXP - 1 - cnt;
- }
+ count_leading_zeros (cnt, res_ptr[N - 1]);
else
{
count_leading_zeros (cnt, res_ptr[0]);
- if (cnt >= NUM_LEADING_ZEROS)
- {
- res_ptr[N - 1] = res_ptr[0] << (cnt - NUM_LEADING_ZEROS);
- res_ptr[0] = 0;
- }
- else
- {
- res_ptr[N - 1] = res_ptr[0] >> (NUM_LEADING_ZEROS - cnt);
- res_ptr[0] <<= BITS_PER_MP_LIMB - (NUM_LEADING_ZEROS - cnt);
- }
- *expt = DBL_MIN_EXP - 1
- - (BITS_PER_MP_LIMB - NUM_LEADING_ZEROS) - cnt;
+ exp -= BITS_PER_MP_LIMB;
+ n = 1;
}
+ *zero_bits = cnt;
+ *expt = exp + NUM_LEADING_ZEROS - cnt;
+ return n;
}
}
else
mp_size_t
__mpn_extract_long_double (mp_ptr res_ptr, mp_size_t size,
- int *expt, int *is_neg,
+ int *expt, int *zero_bits, int *is_neg,
long double value)
{
union ieee854_long_double u;
#else
#error "mp_limb size " BITS_PER_MP_LIMB "not accounted for"
#endif
+
/* The format does not fill the last limb. There are some zeros. */
-#define NUM_LEADING_ZEROS (BITS_PER_MP_LIMB \
- - (LDBL_MANT_DIG - ((N - 1) * BITS_PER_MP_LIMB)))
+#define NUM_LEADING_ZEROS (N * BITS_PER_MP_LIMB - LDBL_MANT_DIG)
+ *zero_bits = NUM_LEADING_ZEROS;
if (u.ieee.exponent == 0)
{
Either it is a zero or it is a denormal number. */
if (res_ptr[0] == 0 && res_ptr[1] == 0
&& res_ptr[N - 2] == 0 && res_ptr[N - 1] == 0) /* Assumes N<=4. */
- /* It's zero. */
- *expt = 0;
+ {
+ /* It's zero. */
+ *expt = 0;
+ return 1;
+ }
else
{
/* It is a denormal number, meaning it has no implicit leading
one bit, and its exponent is in fact the format minimum. */
int cnt;
+ int exp = 1 - IEEE854_LONG_DOUBLE_BIAS;
+ int n = N;
#if N == 2
if (res_ptr[N - 1] != 0)
- {
- count_leading_zeros (cnt, res_ptr[N - 1]);
- cnt -= NUM_LEADING_ZEROS;
- res_ptr[N - 1] = res_ptr[N - 1] << cnt
- | (res_ptr[0] >> (BITS_PER_MP_LIMB - cnt));
- res_ptr[0] <<= cnt;
- *expt = LDBL_MIN_EXP - 1 - cnt;
- }
+ count_leading_zeros (cnt, res_ptr[N - 1]);
else
{
count_leading_zeros (cnt, res_ptr[0]);
- if (cnt >= NUM_LEADING_ZEROS)
- {
- res_ptr[N - 1] = res_ptr[0] << (cnt - NUM_LEADING_ZEROS);
- res_ptr[0] = 0;
- }
- else
- {
- res_ptr[N - 1] = res_ptr[0] >> (NUM_LEADING_ZEROS - cnt);
- res_ptr[0] <<= BITS_PER_MP_LIMB - (NUM_LEADING_ZEROS - cnt);
- }
- *expt = LDBL_MIN_EXP - 1
- - (BITS_PER_MP_LIMB - NUM_LEADING_ZEROS) - cnt;
+ exp -= BITS_PER_MP_LIMB;
+ n = 1;
}
#else
- int j, k, l;
+ int j;
for (j = N - 1; j > 0; j--)
if (res_ptr[j] != 0)
break;
count_leading_zeros (cnt, res_ptr[j]);
- cnt -= NUM_LEADING_ZEROS;
- l = N - 1 - j;
- if (cnt < 0)
- {
- cnt += BITS_PER_MP_LIMB;
- l--;
- }
- if (!cnt)
- for (k = N - 1; k >= l; k--)
- res_ptr[k] = res_ptr[k-l];
- else
- {
- for (k = N - 1; k > l; k--)
- res_ptr[k] = res_ptr[k-l] << cnt
- | res_ptr[k-l-1] >> (BITS_PER_MP_LIMB - cnt);
- res_ptr[k--] = res_ptr[0] << cnt;
- }
-
- for (; k >= 0; k--)
- res_ptr[k] = 0;
- *expt = LDBL_MIN_EXP - 1 - l * BITS_PER_MP_LIMB - cnt;
+ exp -= (N - 1 - j) * BITS_PER_MP_LIMB;
+ n = j + 1;
#endif
+ *zero_bits = cnt;
+ *expt = exp + NUM_LEADING_ZEROS - cnt;
+ return n;
}
}
else
mp_size_t
__mpn_extract_long_double (mp_ptr res_ptr, mp_size_t size,
- int *expt, int *is_neg,
+ int *expt, int *zero_bits, int *is_neg,
long double value)
{
union ibm_extended_long_double u;
- unsigned long long hi, lo;
+ uint64_t hi, lo;
int ediff;
u.ld = value;
*is_neg = u.d[0].ieee.negative;
*expt = (int) u.d[0].ieee.exponent - IEEE754_DOUBLE_BIAS;
+#define NUM_LEADING_ZEROS (128 - (LDBL_MANT_DIG + 11))
+ *zero_bits = NUM_LEADING_ZEROS;
- lo = ((long long) u.d[1].ieee.mantissa0 << 32) | u.d[1].ieee.mantissa1;
- hi = ((long long) u.d[0].ieee.mantissa0 << 32) | u.d[0].ieee.mantissa1;
+ lo = ((uint64_t) u.d[1].ieee.mantissa0 << 32) | u.d[1].ieee.mantissa1;
+ hi = ((uint64_t) u.d[0].ieee.mantissa0 << 32) | u.d[0].ieee.mantissa1;
- /* If the lower double is not a denormal or zero then set the hidden
- 53rd bit. */
- if (u.d[1].ieee.exponent != 0)
- lo |= 1ULL << 52;
- else
- lo = lo << 1;
-
- /* The lower double is normalized separately from the upper. We may
- need to adjust the lower manitissa to reflect this. */
- ediff = u.d[0].ieee.exponent - u.d[1].ieee.exponent - 53;
- if (ediff > 0)
+ if (u.d[0].ieee.exponent != 0)
{
- if (ediff < 64)
- lo = lo >> ediff;
+ /* If the high double is not a denormal or zero then set the hidden
+ 53rd bit. */
+ hi |= (uint64_t) 1 << 52;
+
+ /* If the lower double is not a denormal or zero then set the hidden
+ 53rd bit. */
+ if (u.d[1].ieee.exponent != 0)
+ lo |= (uint64_t) 1 << 52;
else
- lo = 0;
- }
- else if (ediff < 0)
- lo = lo << -ediff;
-
- /* The high double may be rounded and the low double reflects the
- difference between the long double and the rounded high double
- value. This is indicated by a differnce between the signs of the
- high and low doubles. */
- if (u.d[0].ieee.negative != u.d[1].ieee.negative
- && lo != 0)
- {
- lo = (1ULL << 53) - lo;
- if (hi == 0)
+ lo = lo << 1;
+
+ /* We currently only have 53 bits in lo. Gain a few more bits
+ of precision. */
+ lo = lo << 11;
+
+ /* The lower double is normalized separately from the upper. We may
+ need to adjust the lower manitissa to reflect this. */
+ ediff = u.d[0].ieee.exponent - u.d[1].ieee.exponent - 53;
+ if (ediff > 0)
{
- /* we have a borrow from the hidden bit, so shift left 1. */
- hi = 0x0ffffffffffffeLL | (lo >> 51);
- lo = 0x1fffffffffffffLL & (lo << 1);
- (*expt)--;
+ if (ediff < 64)
+ lo = lo >> ediff;
+ else
+ lo = 0;
}
- else
- hi--;
- }
+ else if (ediff < 0)
+ lo = lo << -ediff;
+
+ /* The high double may be rounded and the low double reflects the
+ difference between the long double and the rounded high double
+ value. This is indicated by a differnce between the signs of the
+ high and low doubles. */
+ if (u.d[0].ieee.negative != u.d[1].ieee.negative
+ && lo != 0)
+ {
+ hi--;
+ lo = -lo;
+ if (hi < (uint64_t) 1 << 52)
+ {
+ /* We have a borrow from the hidden bit, so shift left 1. */
+ hi = (hi << 1) | (lo >> 63);
+ lo = lo << 1;
+ (*expt)--;
+ }
+ }
+
#if BITS_PER_MP_LIMB == 32
- /* Combine the mantissas to be contiguous. */
- res_ptr[0] = lo;
- res_ptr[1] = (hi << (53 - 32)) | (lo >> 32);
- res_ptr[2] = hi >> 11;
- res_ptr[3] = hi >> (32 + 11);
- #define N 4
+ res_ptr[0] = lo;
+ res_ptr[1] = lo >> 32;
+ res_ptr[2] = hi;
+ res_ptr[3] = hi >> 32;
+ return 4;
#elif BITS_PER_MP_LIMB == 64
- /* Combine the two mantissas to be contiguous. */
- res_ptr[0] = (hi << 53) | lo;
- res_ptr[1] = hi >> 11;
- #define N 2
+ res_ptr[0] = lo;
+ res_ptr[1] = hi;
+ return 2;
#else
- #error "mp_limb size " BITS_PER_MP_LIMB "not accounted for"
+# error "mp_limb size " BITS_PER_MP_LIMB "not accounted for"
#endif
-/* The format does not fill the last limb. There are some zeros. */
-#define NUM_LEADING_ZEROS (BITS_PER_MP_LIMB \
- - (LDBL_MANT_DIG - ((N - 1) * BITS_PER_MP_LIMB)))
+ }
- if (u.d[0].ieee.exponent == 0)
+ /* The high double is a denormal or zero. The low double must
+ be zero. A denormal is interpreted as having a biased
+ exponent of 1. */
+ res_ptr[0] = hi;
+#if BITS_PER_MP_LIMB == 32
+ res_ptr[1] = hi >> 32;
+#endif
+ if (hi == 0)
{
- /* A biased exponent of zero is a special case.
- Either it is a zero or it is a denormal number. */
- if (res_ptr[0] == 0 && res_ptr[1] == 0
- && res_ptr[N - 2] == 0 && res_ptr[N - 1] == 0) /* Assumes N<=4. */
- /* It's zero. */
- *expt = 0;
+ /* It's zero. */
+ *expt = 0;
+ return 1;
+ }
+ else
+ {
+ int cnt;
+ int exp = 1 - IEEE754_DOUBLE_BIAS;
+ int n = 1;
+
+#if BITS_PER_MP_LIMB == 32
+ if (res_ptr[1] != 0)
+ {
+ count_leading_zeros (cnt, res_ptr[1]);
+ n = 2;
+ }
else
{
- /* It is a denormal number, meaning it has no implicit leading
- one bit, and its exponent is in fact the format minimum. We
- use DBL_MIN_EXP instead of LDBL_MIN_EXP below because the
- latter describes the properties of both parts together, but
- the exponent is computed from the high part only. */
- int cnt;
-
-#if N == 2
- if (res_ptr[N - 1] != 0)
- {
- count_leading_zeros (cnt, res_ptr[N - 1]);
- cnt -= NUM_LEADING_ZEROS;
- res_ptr[N - 1] = res_ptr[N - 1] << cnt
- | (res_ptr[0] >> (BITS_PER_MP_LIMB - cnt));
- res_ptr[0] <<= cnt;
- *expt = DBL_MIN_EXP - 1 - cnt;
- }
- else
- {
- count_leading_zeros (cnt, res_ptr[0]);
- if (cnt >= NUM_LEADING_ZEROS)
- {
- res_ptr[N - 1] = res_ptr[0] << (cnt - NUM_LEADING_ZEROS);
- res_ptr[0] = 0;
- }
- else
- {
- res_ptr[N - 1] = res_ptr[0] >> (NUM_LEADING_ZEROS - cnt);
- res_ptr[0] <<= BITS_PER_MP_LIMB - (NUM_LEADING_ZEROS - cnt);
- }
- *expt = DBL_MIN_EXP - 1
- - (BITS_PER_MP_LIMB - NUM_LEADING_ZEROS) - cnt;
- }
+ count_leading_zeros (cnt, res_ptr[0]);
+ exp -= BITS_PER_MP_LIMB;
+ }
#else
- int j, k, l;
-
- for (j = N - 1; j > 0; j--)
- if (res_ptr[j] != 0)
- break;
-
- count_leading_zeros (cnt, res_ptr[j]);
- cnt -= NUM_LEADING_ZEROS;
- l = N - 1 - j;
- if (cnt < 0)
- {
- cnt += BITS_PER_MP_LIMB;
- l--;
- }
- if (!cnt)
- for (k = N - 1; k >= l; k--)
- res_ptr[k] = res_ptr[k-l];
- else
- {
- for (k = N - 1; k > l; k--)
- res_ptr[k] = res_ptr[k-l] << cnt
- | res_ptr[k-l-1] >> (BITS_PER_MP_LIMB - cnt);
- res_ptr[k--] = res_ptr[0] << cnt;
- }
-
- for (; k >= 0; k--)
- res_ptr[k] = 0;
- *expt = DBL_MIN_EXP - 1 - l * BITS_PER_MP_LIMB - cnt;
+ count_leading_zeros (cnt, hi);
#endif
- }
+ *zero_bits = cnt;
+ *expt = exp + NUM_LEADING_ZEROS - cnt;
+ return n;
}
- else
- /* Add the implicit leading one bit for a normalized number. */
- res_ptr[N - 1] |= (mp_limb_t) 1 << (LDBL_MANT_DIG - 1
- - ((N - 1) * BITS_PER_MP_LIMB));
-
- return N;
}
mp_size_t
__mpn_extract_long_double (mp_ptr res_ptr, mp_size_t size,
- int *expt, int *is_neg,
+ int *expt, int *zero_bits, int *is_neg,
long double value)
{
union ieee854_long_double u;
#error "mp_limb size " BITS_PER_MP_LIMB "not accounted for"
#endif
+/* The format does not fill the last limb. There are some zeros. */
+#define NUM_LEADING_ZEROS (N * BITS_PER_MP_LIMB - LDBL_MANT_DIG)
+ *zero_bits = NUM_LEADING_ZEROS;
+
if (u.ieee.exponent == 0)
{
/* A biased exponent of zero is a special case.
Either it is a zero or it is a denormal number. */
if (res_ptr[0] == 0 && res_ptr[N - 1] == 0) /* Assumes N<=2. */
- /* It's zero. */
- *expt = 0;
+ {
+ /* It's zero. */
+ *expt = 0;
+ return 1;
+ }
else
{
/* It is a denormal number, meaning it has no implicit leading
one bit, and its exponent is in fact the format minimum. */
int cnt;
+ int exp = 1 - IEEE854_LONG_DOUBLE_BIAS;
+ int n = N;
if (res_ptr[N - 1] != 0)
- {
- count_leading_zeros (cnt, res_ptr[N - 1]);
- if (cnt != 0)
- {
-#if N == 2
- res_ptr[N - 1] = res_ptr[N - 1] << cnt
- | (res_ptr[0] >> (BITS_PER_MP_LIMB - cnt));
- res_ptr[0] <<= cnt;
-#else
- res_ptr[N - 1] <<= cnt;
-#endif
- }
- *expt = LDBL_MIN_EXP - 1 - cnt;
- }
+ count_leading_zeros (cnt, res_ptr[N - 1]);
else
{
count_leading_zeros (cnt, res_ptr[0]);
- res_ptr[N - 1] = res_ptr[0] << cnt;
- res_ptr[0] = 0;
- *expt = LDBL_MIN_EXP - 1 - BITS_PER_MP_LIMB - cnt;
+ exp -= BITS_PER_MP_LIMB;
+ n = 1;
}
+ *zero_bits = cnt;
+ *expt = exp + NUM_LEADING_ZEROS - cnt;
}
}
projects / thirdparty / glibc.git / commitdiff
