/* Occurs in branches/new-sum/src/sum.c@9344 on a 64-bit machine. */
static void
bug20150327 (void)
{
mpfr_t sum1, sum2, t[3];
mpfr_ptr p[3];
char *s[3] = { "0.10000111110101000010101011100001", "1E-100", "0.1E95" };
int i, r;
mpfr_inits2 (58, sum1, sum2, (mpfr_ptr) 0);
for (i = 0; i < 3; i++)
{
mpfr_init2 (t[i], 64);
mpfr_set_str (t[i], s[i], 2, MPFR_RNDN);
p[i] = t[i];
}
RND_LOOP(r)
{
int inex1, inex2;
mpfr_set (sum1, t[2], MPFR_RNDN);
inex1 = -1;
if (MPFR_IS_LIKE_RNDU ((mpfr_rnd_t) r, 1))
{
mpfr_nextabove (sum1);
inex1 = 1;
}
inex2 = mpfr_sum (sum2, p, 3, (mpfr_rnd_t) r);
if (!(mpfr_equal_p (sum1, sum2) && SAME_SIGN (inex1, inex2)))
{
printf ("mpfr_sum incorrect in bug20150327 for %s:\n",
mpfr_print_rnd_mode ((mpfr_rnd_t) r));
printf ("Expected ");
mpfr_dump (sum1);
printf ("with inex = %d\n", inex1);
printf ("Got ");
mpfr_dump (sum2);
printf ("with inex = %d\n", inex2);
exit (1);
}
}
for (i = 0; i < 3; i++)
mpfr_clear (t[i]);
mpfr_clears (sum1, sum2, (mpfr_ptr) 0);
}
static int
sum_tab (mpfr_ptr ret, mpfr_t *tab, unsigned long n, mpfr_rnd_t rnd)
{
mpfr_ptr *tabtmp;
unsigned long i;
int inexact;
MPFR_TMP_DECL(marker);
MPFR_TMP_MARK(marker);
tabtmp = (mpfr_ptr *) MPFR_TMP_ALLOC(n * sizeof(mpfr_srcptr));
for (i = 0; i < n; i++)
tabtmp[i] = tab[i];
inexact = mpfr_sum (ret, tabtmp, n, rnd);
MPFR_TMP_FREE(marker);
return inexact;
}
/* bug reported by Joseph S. Myers on 2013-10-27
https://sympa.inria.fr/sympa/arc/mpfr/2013-10/msg00015.html */
static void
bug20131027 (void)
{
mpfr_t sum, t[4];
mpfr_ptr p[4];
char *s[4] = {
"0x1p1000",
"-0x0.fffffffffffff80000000000000001p1000",
"-0x1p947",
"0x1p880"
};
int i, r;
mpfr_init2 (sum, 53);
for (i = 0; i < 4; i++)
{
mpfr_init2 (t[i], i == 0 ? 53 : 1000);
mpfr_set_str (t[i], s[i], 0, MPFR_RNDN);
p[i] = t[i];
}
RND_LOOP(r)
{
int expected_sign = (mpfr_rnd_t) r == MPFR_RNDD ? -1 : 1;
int inex;
inex = mpfr_sum (sum, p, 4, (mpfr_rnd_t) r);
if (MPFR_NOTZERO (sum) || MPFR_SIGN (sum) != expected_sign || inex != 0)
{
printf ("mpfr_sum incorrect in bug20131027 for %s:\n"
"expected %c0 with inex = 0, got ",
mpfr_print_rnd_mode ((mpfr_rnd_t) r),
expected_sign > 0 ? '+' : '-');
mpfr_dump (sum);
printf ("with inex = %d\n", inex);
exit (1);
}
}
for (i = 0; i < 4; i++)
mpfr_clear (t[i]);
mpfr_clear (sum);
}
/* check adding n random numbers, iterated k times */
static void
check_random (int n, int k, mpfr_prec_t prec, mpfr_rnd_t rnd)
{
mpfr_t *x, s, ref_s;
mpfr_ptr *y;
int i, st, ret = 0, ref_ret = 0;
gmp_randstate_t state;
gmp_randinit_default (state);
mpfr_init2 (s, prec);
mpfr_init2 (ref_s, prec);
x = (mpfr_t *) tests_allocate (n * sizeof (mpfr_t));
y = (mpfr_ptr *) tests_allocate (n * sizeof (mpfr_ptr));
for (i = 0; i < n; i++)
{
y[i] = x[i];
mpfr_init2 (x[i], prec);
mpfr_urandom (x[i], state, rnd);
}
st = cputime ();
for (i = 0; i < k; i++)
ref_ret = mpfr_sum_naive (ref_s, x, n, rnd);
printf ("mpfr_sum_naive took %dms\n", cputime () - st);
st = cputime ();
for (i = 0; i < k; i++)
ret = mpfr_sum (s, y, n, rnd);
printf ("mpfr_sum took %dms\n", cputime () - st);
if (n <= 2)
{
MPFR_ASSERTN (mpfr_cmp (ref_s, s) == 0);
MPFR_ASSERTN (ref_ret == ret);
}
for (i = 0; i < n; i++)
mpfr_clear (x[i]);
tests_free (x, n * sizeof (mpfr_t));
tests_free (y, n * sizeof (mpfr_ptr));
mpfr_clear (s);
mpfr_clear (ref_s);
gmp_randclear (state);
}
/* TODO: A test with more inputs (but can't be compared to mpfr_add). */
static void
check_extreme (void)
{
mpfr_t u, v, w, x, y;
mpfr_ptr t[2];
int i, inex1, inex2, r;
t[0] = u;
t[1] = v;
mpfr_inits2 (32, u, v, w, x, y, (mpfr_ptr) 0);
mpfr_setmin (u, mpfr_get_emax ());
mpfr_setmax (v, mpfr_get_emin ());
mpfr_setmin (w, mpfr_get_emax () - 40);
RND_LOOP (r)
for (i = 0; i < 2; i++)
{
mpfr_set_prec (x, 64);
inex1 = mpfr_add (x, u, w, MPFR_RNDN);
MPFR_ASSERTN (inex1 == 0);
inex1 = mpfr_prec_round (x, 32, (mpfr_rnd_t) r);
inex2 = mpfr_sum (y, t, 2, (mpfr_rnd_t) r);
if (!(mpfr_equal_p (x, y) && SAME_SIGN (inex1, inex2)))
{
printf ("Error in check_extreme (%s, i = %d)\n",
mpfr_print_rnd_mode ((mpfr_rnd_t) r), i);
printf ("Expected ");
mpfr_dump (x);
printf ("with inex = %d\n", inex1);
printf ("Got ");
mpfr_dump (y);
printf ("with inex = %d\n", inex2);
exit (1);
}
mpfr_neg (v, v, MPFR_RNDN);
mpfr_neg (w, w, MPFR_RNDN);
}
mpfr_clears (u, v, w, x, y, (mpfr_ptr) 0);
}
static void tableau(mpfr_t ret, int i, int j) {
int k;
if (col[i] < 0) { mpfr_set_d(ret, 0, GMP_RNDN); return; }
if (j <= n) {
mpfr_t s;
mpfr_zinit(s);
mpfr_set_d(s, 0, GMP_RNDN);
mpfr_t *tab = malloc(sizeof(mpfr_t) * (m + 1));
mpfr_ptr *ptab = malloc(sizeof(mpfr_ptr) * (m + 1));
for (k = 0; k <= m; k++) {
mpfr_zinit(tab[k]);
ptab[k] = (mpfr_ptr)&tab[k];
mpfr_mul(tab[k], q[i][k], a[k][j], GMP_RNDN);
}
mpfr_sum(s, ptab, m+1, GMP_RNDN);
for (k = 0; k <= m; k++) {
mpfr_clear(tab[k]);
}
free(ptab);
free(tab);
mpfr_set(ret, s, GMP_RNDN);
mpfr_clear(s);
return;
}
mpfr_set(ret, q[i][nonzero_row[j]], GMP_RNDN);
if (j <= n1) { mpfr_neg(ret, ret, GMP_RNDN); return; }
if (j <= n2 || i != 0) return;
mpfr_add(ret, ret, one, GMP_RNDN);
return;
}
/* glibc free() error or segmentation fault when configured
* with GMP 6.0.0 built with "--disable-alloca ABI=32".
* GCC's address sanitizer shows a heap-buffer-overflow.
* Fixed in r9369 (before the merge into the trunk). The problem was due
* to the fact that mpn functions do not accept a zero size argument, and
* since mpn_add_1 is here a macro in GMP, there's no assertion even when
* GMP was built with assertion checking (--enable-assert).
*/
static
void check_simple (void)
{
mpfr_t tab[3], r;
mpfr_ptr tabp[3];
int i;
mpfr_init2 (r, 16);
for (i = 0; i < 3; i++)
{
mpfr_init2 (tab[i], 16);
mpfr_set_ui (tab[i], 1, MPFR_RNDN);
tabp[i] = tab[i];
}
i = mpfr_sum (r, tabp, 3, MPFR_RNDN);
if (mpfr_cmp_ui (r, 3) || i != 0)
{
printf ("Error in check_simple\n");
exit (1);
}
mpfr_clears (tab[0], tab[1], tab[2], r, (mpfr_ptr) 0);
}
static void
check_underflow (void)
{
mpfr_t sum1, sum2, t[NUNFL];
mpfr_ptr p[NUNFL];
mpfr_prec_t precmax = 444;
mpfr_exp_t emin, emax;
unsigned int ex_flags, flags;
int c, i;
emin = mpfr_get_emin ();
emax = mpfr_get_emax ();
set_emin (MPFR_EMIN_MIN);
set_emax (MPFR_EMAX_MAX);
ex_flags = MPFR_FLAGS_UNDERFLOW | MPFR_FLAGS_INEXACT;
mpfr_init2 (sum1, MPFR_PREC_MIN);
mpfr_init2 (sum2, precmax);
for (i = 0; i < NUNFL; i++)
{
mpfr_init2 (t[i], precmax);
p[i] = t[i];
}
for (c = 0; c < 8; c++)
{
mpfr_prec_t fprec;
int n, neg, r;
fprec = MPFR_PREC_MIN + (randlimb () % (precmax - MPFR_PREC_MIN + 1));
n = 3 + (randlimb () % (NUNFL - 2));
MPFR_ASSERTN (n <= NUNFL);
mpfr_set_prec (sum2, (randlimb () & 1) ? MPFR_PREC_MIN : precmax);
mpfr_set_prec (t[0], fprec + 64);
mpfr_set_zero (t[0], 1);
for (i = 1; i < n; i++)
{
int inex;
mpfr_set_prec (t[i], MPFR_PREC_MIN +
(randlimb () % (fprec - MPFR_PREC_MIN + 1)));
do
mpfr_urandomb (t[i], RANDS);
while (MPFR_IS_ZERO (t[i]));
mpfr_set_exp (t[i], MPFR_EMIN_MIN);
inex = mpfr_sub (t[0], t[0], t[i], MPFR_RNDN);
MPFR_ASSERTN (inex == 0);
}
neg = randlimb () & 1;
if (neg)
mpfr_nextbelow (t[0]);
else
mpfr_nextabove (t[0]);
RND_LOOP(r)
{
int inex1, inex2;
mpfr_set_zero (sum1, 1);
if (neg)
mpfr_nextbelow (sum1);
else
mpfr_nextabove (sum1);
inex1 = mpfr_div_2ui (sum1, sum1, 2, (mpfr_rnd_t) r);
mpfr_clear_flags ();
inex2 = mpfr_sum (sum2, p, n, (mpfr_rnd_t) r);
flags = __gmpfr_flags;
MPFR_ASSERTN (mpfr_check (sum1));
MPFR_ASSERTN (mpfr_check (sum2));
if (flags != ex_flags)
{
printf ("Bad flags in check_underflow on %s, c = %d\n",
mpfr_print_rnd_mode ((mpfr_rnd_t) r), c);
printf ("Expected flags:");
flags_out (ex_flags);
printf ("Got flags: ");
flags_out (flags);
printf ("sum = ");
mpfr_dump (sum2);
exit (1);
}
if (!(mpfr_equal_p (sum1, sum2) && SAME_SIGN (inex1, inex2)))
{
printf ("Error in check_underflow on %s, c = %d\n",
mpfr_print_rnd_mode ((mpfr_rnd_t) r), c);
printf ("Expected ");
mpfr_dump (sum1);
printf ("with inex = %d\n", inex1);
printf ("Got ");
mpfr_dump (sum2);
printf ("with inex = %d\n", inex2);
exit (1);
}
}
}
for (i = 0; i < NUNFL; i++)
mpfr_clear (t[i]);
mpfr_clears (sum1, sum2, (mpfr_ptr) 0);
set_emin (emin);
set_emax (emax);
}
static
void check_special (void)
{
mpfr_t tab[3], r;
mpfr_ptr tabp[3];
int i;
mpfr_inits (tab[0], tab[1], tab[2], r, (mpfr_ptr) 0);
tabp[0] = tab[0];
tabp[1] = tab[1];
tabp[2] = tab[2];
i = mpfr_sum (r, tabp, 0, MPFR_RNDN);
if (!MPFR_IS_ZERO (r) || !MPFR_IS_POS (r) || i != 0)
{
printf ("Special case n==0 failed!\n");
exit (1);
}
mpfr_set_ui (tab[0], 42, MPFR_RNDN);
i = mpfr_sum (r, tabp, 1, MPFR_RNDN);
if (mpfr_cmp_ui (r, 42) || i != 0)
{
printf ("Special case n==1 failed!\n");
exit (1);
}
mpfr_set_ui (tab[1], 17, MPFR_RNDN);
MPFR_SET_NAN (tab[2]);
i = mpfr_sum (r, tabp, 3, MPFR_RNDN);
if (!MPFR_IS_NAN (r) || i != 0)
{
printf ("Special case NAN failed!\n");
exit (1);
}
MPFR_SET_INF (tab[2]);
MPFR_SET_POS (tab[2]);
i = mpfr_sum (r, tabp, 3, MPFR_RNDN);
if (!MPFR_IS_INF (r) || !MPFR_IS_POS (r) || i != 0)
{
printf ("Special case +INF failed!\n");
exit (1);
}
MPFR_SET_INF (tab[2]);
MPFR_SET_NEG (tab[2]);
i = mpfr_sum (r, tabp, 3, MPFR_RNDN);
if (!MPFR_IS_INF (r) || !MPFR_IS_NEG (r) || i != 0)
{
printf ("Special case -INF failed!\n");
exit (1);
}
MPFR_SET_ZERO (tab[1]);
i = mpfr_sum (r, tabp, 2, MPFR_RNDN);
if (mpfr_cmp_ui (r, 42) || i != 0)
{
printf ("Special case 42+0 failed!\n");
exit (1);
}
MPFR_SET_NAN (tab[0]);
i = mpfr_sum (r, tabp, 3, MPFR_RNDN);
if (!MPFR_IS_NAN (r) || i != 0)
{
printf ("Special case NAN+0+-INF failed!\n");
exit (1);
}
mpfr_set_inf (tab[0], 1);
mpfr_set_ui (tab[1], 59, MPFR_RNDN);
mpfr_set_inf (tab[2], -1);
i = mpfr_sum (r, tabp, 3, MPFR_RNDN);
if (!MPFR_IS_NAN (r) || i != 0)
{
printf ("Special case +INF + 59 +-INF failed!\n");
exit (1);
}
mpfr_clears (tab[0], tab[1], tab[2], r, (mpfr_ptr) 0);
}
static PyObject *
GMPy_Context_Fsum(PyObject *self, PyObject *other)
{
MPFR_Object *temp, *result;
mpfr_ptr *tab;
int errcode;
Py_ssize_t i, seq_length = 0;
CTXT_Object *context = NULL;
if (self && CTXT_Check(self)) {
context = (CTXT_Object*)self;
}
else {
CHECK_CONTEXT(context);
}
if (!(result = GMPy_MPFR_New(0, context))) {
return NULL;
}
if (!(other = PySequence_List(other))) {
Py_DECREF((PyObject*)result);
TYPE_ERROR("argument must be an iterable");
return NULL;
}
/* other contains a new list containing all the values from the
* iterable. Now make sure each item in the list is an mpfr.
*/
seq_length = PyList_GET_SIZE(other);
for (i=0; i < seq_length; i++) {
if (!(temp = GMPy_MPFR_From_Real(PyList_GET_ITEM(other, i), 1, context))) {
Py_DECREF(other);
Py_DECREF((PyObject*)result);
TYPE_ERROR("all items in iterable must be real numbers");
return NULL;
}
errcode = PyList_SetItem(other, i,(PyObject*)temp);
if (errcode < 0) {
Py_DECREF(other);
Py_DECREF((PyObject*)result);
TYPE_ERROR("all items in iterable must be real numbers");
return NULL;
}
}
/* create an array of pointers to the mpfr_t field of a Pympfr object */
if (!(tab = (mpfr_ptr *)GMPY_MALLOC((sizeof(mpfr_srcptr) * seq_length)))) {
Py_DECREF(other);
Py_DECREF((PyObject*)result);
return PyErr_NoMemory();
}
for (i=0; i < seq_length; i++) {
temp = (MPFR_Object*)PyList_GET_ITEM(other, i);
tab[i] = temp->f;
}
mpfr_clear_flags();
result->rc = mpfr_sum(result->f, tab, seq_length, GET_MPFR_ROUND(context));
Py_DECREF(other);
GMPY_FREE(tab);
_GMPy_MPFR_Cleanup(&result, context);
return (PyObject*)result;
}
/* Generic random tests with cancellations.
*
* In summary, we do 4000 tests of the following form:
* 1. We set the first MPFR_NCANCEL members of an array to random values,
* with a random exponent taken in 4 ranges, depending on the value of
* i % 4 (see code below).
* 2. For each of the next MPFR_NCANCEL iterations:
* A. we randomly permute some terms of the array (to make sure that a
* particular order doesn't have an influence on the result);
* B. we compute the sum in a random rounding mode;
* C. if this sum is zero, we end the current test (there is no longer
* anything interesting to test);
* D. we check that this sum is below some bound (chosen as infinite
* for the first iteration of (2), i.e. this test will be useful
* only for the next iterations, after cancellations);
* E. we put the opposite of this sum in the array, the goal being to
* introduce a chain of cancellations;
* F. we compute the bound for the next iteration, derived from (E).
* 3. We do another iteration like (2), but with reusing a random element
* of the array. This last test allows one to check the support of
* reused arguments. Before this support (r10467), it triggers an
* assertion failure with (almost?) all seeds, and if assertions are
* not checked, tsum fails in most cases but not all.
*/
static void
cancel (void)
{
mpfr_t x[2 * MPFR_NCANCEL], bound;
mpfr_ptr px[2 * MPFR_NCANCEL];
int i, j, k, n;
mpfr_init2 (bound, 2);
/* With 4000 tests, tsum will fail in most cases without support of
reused arguments (before r10467). */
for (i = 0; i < 4000; i++)
{
mpfr_set_inf (bound, 1);
for (n = 0; n <= numberof (x); n++)
{
mpfr_prec_t p;
mpfr_rnd_t rnd;
if (n < numberof (x))
{
px[n] = x[n];
p = MPFR_PREC_MIN + (randlimb () % 256);
mpfr_init2 (x[n], p);
k = n;
}
else
{
/* Reuse of a random member of the array. */
k = randlimb () % n;
}
if (n < MPFR_NCANCEL)
{
mpfr_exp_t e;
MPFR_ASSERTN (n < numberof (x));
e = (i & 1) ? 0 : mpfr_get_emin ();
tests_default_random (x[n], 256, e,
((i & 2) ? e + 2000 : mpfr_get_emax ()),
0);
}
else
{
/* random permutation with n random transpositions */
for (j = 0; j < n; j++)
{
int k1, k2;
k1 = randlimb () % (n-1);
k2 = randlimb () % (n-1);
mpfr_swap (x[k1], x[k2]);
}
rnd = RND_RAND ();
#if DEBUG
printf ("mpfr_sum cancellation test\n");
for (j = 0; j < n; j++)
{
printf (" x%d[%3ld] = ", j, mpfr_get_prec(x[j]));
mpfr_out_str (stdout, 16, 0, x[j], MPFR_RNDN);
printf ("\n");
}
printf (" rnd = %s, output prec = %ld\n",
mpfr_print_rnd_mode (rnd), mpfr_get_prec (x[n]));
#endif
mpfr_sum (x[k], px, n, rnd);
if (mpfr_zero_p (x[k]))
{
if (k == n)
n++;
break;
}
if (mpfr_cmpabs (x[k], bound) > 0)
{
printf ("Error in cancel on i = %d, n = %d\n", i, n);
printf ("Expected bound: ");
mpfr_dump (bound);
printf ("x[%d]: ", k);
mpfr_dump (x[k]);
exit (1);
}
if (k != n)
break;
/* For the bound, use MPFR_RNDU due to possible underflow.
It would be nice to add some specific underflow checks,
though there are already ones in check_underflow(). */
mpfr_set_ui_2exp (bound, 1,
mpfr_get_exp (x[n]) - p - (rnd == MPFR_RNDN),
MPFR_RNDU);
/* The next sum will be <= bound in absolute value
(the equality can be obtained in all rounding modes
since the sum will be rounded). */
mpfr_neg (x[n], x[n], MPFR_RNDN);
}
}
while (--n >= 0)
mpfr_clear (x[n]);
}
mpfr_clear (bound);
}
static void
generic_tests (void)
{
mpfr_t exact_sum, sum1, sum2;
mpfr_t *t;
mpfr_ptr *p;
mpfr_prec_t precmax = 444;
int i, m, nmax = 500;
int rnd_mode;
t = (mpfr_t *) tests_allocate (nmax * sizeof(mpfr_t));
p = (mpfr_ptr *) tests_allocate (nmax * sizeof(mpfr_ptr));
for (i = 0; i < nmax; i++)
{
mpfr_init2 (t[i], precmax);
p[i] = t[i];
}
mpfr_inits2 (precmax, exact_sum, sum1, sum2, (mpfr_ptr) 0);
for (m = 0; m < 4000; m++)
{
int non_uniform, n;
mpfr_prec_t prec;
non_uniform = randlimb () % 10;
n = (randlimb () % nmax) + 1;
prec = MPFR_PREC_MIN + (randlimb () % (precmax - MPFR_PREC_MIN + 1));
mpfr_set_prec (sum1, prec);
mpfr_set_prec (sum2, prec);
for (i = 0; i < n; i++)
{
mpfr_set_prec (t[i], MPFR_PREC_MIN +
(randlimb () % (precmax - MPFR_PREC_MIN + 1)));
mpfr_urandomb (t[i], RANDS);
if (m % 8 != 0 && (m % 8 == 1 || (randlimb () & 1)))
mpfr_neg (t[i], t[i], MPFR_RNDN);
if (non_uniform && MPFR_NOTZERO (t[i]))
mpfr_set_exp (t[i], randlimb () % 1000);
/* putchar ("-0+"[SIGN (mpfr_sgn (t[i])) + 1]); */
}
/* putchar ('\n'); */
get_exact_sum (exact_sum, t, n);
RND_LOOP (rnd_mode)
{
int inex1, inex2;
inex1 = mpfr_set (sum1, exact_sum, (mpfr_rnd_t) rnd_mode);
inex2 = mpfr_sum (sum2, p, n, (mpfr_rnd_t) rnd_mode);
if (!(mpfr_equal_p (sum1, sum2) && SAME_SIGN (inex1, inex2)))
{
printf ("generic_tests failed on m = %d, %s\n", m,
mpfr_print_rnd_mode ((mpfr_rnd_t) rnd_mode));
printf ("Expected ");
mpfr_dump (sum1);
printf ("with inex = %d\n", inex1);
printf ("Got ");
mpfr_dump (sum2);
printf ("with inex = %d\n", inex2);
exit (1);
}
}
}
for (i = 0; i < nmax; i++)
mpfr_clear (t[i]);
mpfr_clears (exact_sum, sum1, sum2, (mpfr_ptr) 0);
tests_free (t, nmax * sizeof(mpfr_t));
tests_free (p, nmax * sizeof(mpfr_ptr));
}
/* Test of s * (q * 2^(n-1) - 2^k) + h + i * 2^(-2) + j * 2^(-2)
* with h = -1 or 1, -1 <= i odd <= j <= 3, 2 <= q <= 3, s = -1 or 1,
* prec n-k.
* On a 64-bit machine:
* MPFR_RNDN, tmd=2, rbit=0, sst=0, negative is checked with the inputs
* -3*2^58, 2^5, -1, 2^(-2), 3*2^(-2)
* MPFR_RNDN, tmd=2, rbit=0, sst=1, negative is checked with the inputs
* -3*2^58, 2^5, -1, 3*2^(-2), 3*2^(-2)
*
* Note: This test detects an error in a result when "sq + 3" is replaced
* by "sq + 2" (11th argument of the first sum_raw invocation) and the
* corresponding assertion d >= 3 is removed, confirming that one cannot
* decrease this proved error bound.
*/
static void
check4 (void)
{
mpfr_t sum1, sum2, s1, s2, s3, s4, t[5];
mpfr_ptr p[5];
int h, i, j, k, n, q, r, s, prec, inex1, inex2;
mpfr_inits2 (257, sum1, sum2, s1, s2, s3, s4, (mpfr_ptr) 0);
for (i = 0; i < 5; i++)
{
mpfr_init2 (t[i], 2);
p[i] = t[i];
}
/* No GNU style for the many nested loops... */
for (k = 1; k <= 64; k++) {
mpfr_set_si_2exp (t[0], -1, k, MPFR_RNDN);
for (n = k + MPFR_PREC_MIN; n <= k + 65; n++) {
prec = n - k;
mpfr_set_prec (sum1, prec);
mpfr_set_prec (sum2, prec);
for (q = 2; q <= 3; q++) {
mpfr_set_si_2exp (t[1], q, n - 1, MPFR_RNDN);
inex1 = mpfr_add (s1, t[0], t[1], MPFR_RNDN);
MPFR_ASSERTN (inex1 == 0);
for (s = -1; s <= 1; s += 2) {
mpfr_neg (t[0], t[0], MPFR_RNDN);
mpfr_neg (t[1], t[1], MPFR_RNDN);
mpfr_neg (s1, s1, MPFR_RNDN);
for (h = -1; h <= 1; h += 2) {
mpfr_set_si (t[2], h, MPFR_RNDN);
inex1 = mpfr_add (s2, s1, t[2], MPFR_RNDN);
MPFR_ASSERTN (inex1 == 0);
for (i = -1; i <= 3; i += 2) {
mpfr_set_si_2exp (t[3], i, -2, MPFR_RNDN);
inex1 = mpfr_add (s3, s2, t[3], MPFR_RNDN);
MPFR_ASSERTN (inex1 == 0);
for (j = i; j <= 3; j++) {
mpfr_set_si_2exp (t[4], j, -2, MPFR_RNDN);
inex1 = mpfr_add (s4, s3, t[4], MPFR_RNDN);
MPFR_ASSERTN (inex1 == 0);
RND_LOOP (r) {
inex1 = mpfr_set (sum1, s4, (mpfr_rnd_t) r);
inex2 = mpfr_sum (sum2, p, 5, (mpfr_rnd_t) r);
MPFR_ASSERTN (mpfr_check (sum1));
MPFR_ASSERTN (mpfr_check (sum2));
if (!(mpfr_equal_p (sum1, sum2) &&
SAME_SIGN (inex1, inex2)))
{
printf ("Error in check4 on %s, "
"k = %d, n = %d (prec %d), "
"q = %d, s = %d, h = %d, i = %d, j = %d\n",
mpfr_print_rnd_mode ((mpfr_rnd_t) r),
k, n, prec, q, s, h, i, j);
printf ("Expected ");
mpfr_dump (sum1);
printf ("with inex = %d\n", inex1);
printf ("Got ");
mpfr_dump (sum2);
printf ("with inex = %d\n", inex2);
exit (1);
}
}
}
}
}
}
}
}
}
for (i = 0; i < 5; i++)
mpfr_clear (t[i]);
mpfr_clears (sum1, sum2, s1, s2, s3, s4, (mpfr_ptr) 0);
}
/* t[i] = (2^17 - 1) * 2^(17*(i-8)) for 0 <= i <= 16.
* t[17] = 2^(17*9+1) * j for -4 <= j <= 4.
* t[18] = 2^(-1) * k for -1 <= k <= 1.
* t[19] = 2^(-17*8) * m for -3 <= m <= 3.
* prec = MPFR_PREC_MIN and 17*9+4
*/
static void
check3 (void)
{
mpfr_t sum1, sum2, s1, s2, s3, s4, t[20];
mpfr_ptr p[20];
mpfr_flags_t flags1, flags2;
int i, s, j, k, m, q, r, inex1, inex2;
int prec[2] = { MPFR_PREC_MIN, 17*9+4 };
mpfr_init2 (s1, 17*17);
mpfr_init2 (s2, 17*17+4);
mpfr_init2 (s3, 17*17+4);
mpfr_init2 (s4, 17*17+5);
mpfr_set_ui (s1, 0, MPFR_RNDN);
for (i = 0; i < 20; i++)
{
mpfr_init2 (t[i], 20);
p[i] = t[i];
if (i < 17)
{
mpfr_set_ui_2exp (t[i], 0x1ffff, 17*(i-8), MPFR_RNDN);
inex1 = mpfr_add (s1, s1, t[i], MPFR_RNDN);
MPFR_ASSERTN (inex1 == 0);
}
}
for (s = 1; s >= -1; s -= 2)
{
for (j = -4; j <= 4; j++)
{
mpfr_set_si_2exp (t[17], j, 17*9+1, MPFR_RNDN);
inex1 = mpfr_add (s2, s1, t[17], MPFR_RNDN);
MPFR_ASSERTN (inex1 == 0);
for (k = -1; k <= 1; k++)
{
mpfr_set_si_2exp (t[18], k, -1, MPFR_RNDN);
inex1 = mpfr_add (s3, s2, t[18], MPFR_RNDN);
MPFR_ASSERTN (inex1 == 0);
for (m = -3; m <= 3; m++)
{
mpfr_set_si_2exp (t[19], m, -17*8, MPFR_RNDN);
inex1 = mpfr_add (s4, s3, t[19], MPFR_RNDN);
MPFR_ASSERTN (inex1 == 0);
for (q = 0; q < 2; q++)
{
mpfr_inits2 (prec[q], sum1, sum2, (mpfr_ptr) 0);
RND_LOOP (r)
{
mpfr_clear_flags ();
inex1 = mpfr_set (sum1, s4, (mpfr_rnd_t) r);
flags1 = __gmpfr_flags;
mpfr_clear_flags ();
inex2 = mpfr_sum (sum2, p, 20, (mpfr_rnd_t) r);
flags2 = __gmpfr_flags;
MPFR_ASSERTN (mpfr_check (sum1));
MPFR_ASSERTN (mpfr_check (sum2));
if (!(mpfr_equal_p (sum1, sum2) &&
SAME_SIGN (inex1, inex2) &&
flags1 == flags2))
{
printf ("Error in check3 on %s, "
"s = %d, j = %d, k = %d, m = %d\n",
mpfr_print_rnd_mode ((mpfr_rnd_t) r),
s, j, k, m);
printf ("Expected ");
mpfr_dump (sum1);
printf ("with inex = %d and flags =", inex1);
flags_out (flags1);
printf ("Got ");
mpfr_dump (sum2);
printf ("with inex = %d and flags =", inex2);
flags_out (flags2);
exit (1);
}
}
mpfr_clears (sum1, sum2, (mpfr_ptr) 0);
} /* q */
} /* m */
} /* k */
} /* j */
for (i = 0; i < 17; i++)
mpfr_neg (t[i], t[i], MPFR_RNDN);
mpfr_neg (s1, s1, MPFR_RNDN);
} /* s */
for (i = 0; i < 20; i++)
mpfr_clear (t[i]);
mpfr_clears (s1, s2, s3, s4, (mpfr_ptr) 0);
}
/* With N = 2 * GMP_NUMB_BITS:
i * 2^N + j + k * 2^(-1) + f1 * 2^(-N) + f2 * 2^(-N),
with i = -1 or 1, j = 0 or i, -1 <= k <= 1, -1 <= f1 <= 1, -1 <= f2 <= 1
ulp(exact sum) = 2^0. */
static void
check2 (void)
{
mpfr_t sum1, sum2, s1, s2, s3, s4, t[5];
mpfr_ptr p[5];
int i, j, k, f1, f2, prec, r, inex1, inex2;
#define N (2 * GMP_NUMB_BITS)
mpfr_init2 (sum1, N+1);
mpfr_init2 (sum2, N+1);
mpfr_init2 (s1, N+1);
mpfr_init2 (s2, N+2);
mpfr_init2 (s3, 2*N+1);
mpfr_init2 (s4, 2*N+1);
for (i = 0; i < 5; i++)
{
mpfr_init2 (t[i], 2);
p[i] = t[i];
}
for (i = -1; i <= 1; i += 2)
{
mpfr_set_si_2exp (t[0], i, N, MPFR_RNDN);
for (j = 0; j != 2*i; j += i)
{
mpfr_set_si (t[1], j, MPFR_RNDN);
inex1 = mpfr_add (s1, t[0], t[1], MPFR_RNDN);
MPFR_ASSERTN (inex1 == 0);
for (k = -1; k <= 1; k++)
{
mpfr_set_si_2exp (t[2], k, -1, MPFR_RNDN);
inex1 = mpfr_add (s2, s1, t[2], MPFR_RNDN);
MPFR_ASSERTN (inex1 == 0);
for (f1 = -1; f1 <= 1; f1++)
{
mpfr_set_si_2exp (t[3], f1, -N, MPFR_RNDN);
inex1 = mpfr_add (s3, s2, t[3], MPFR_RNDN);
MPFR_ASSERTN (inex1 == 0);
for (f2 = -1; f2 <= 1; f2++)
{
mpfr_set_si_2exp (t[4], f2, -N, MPFR_RNDN);
inex1 = mpfr_add (s4, s3, t[4], MPFR_RNDN);
MPFR_ASSERTN (inex1 == 0);
prec = mpfr_get_exp (s4);
mpfr_set_prec (sum1, prec);
mpfr_set_prec (sum2, prec);
RND_LOOP (r)
{
inex1 = mpfr_set (sum1, s4, (mpfr_rnd_t) r);
inex2 = mpfr_sum (sum2, p, 5, (mpfr_rnd_t) r);
MPFR_ASSERTN (mpfr_check (sum1));
MPFR_ASSERTN (mpfr_check (sum2));
if (!(mpfr_equal_p (sum1, sum2) &&
SAME_SIGN (inex1, inex2)))
{
printf ("Error in check2 on %s, prec = %d, "
"i = %d, j = %d, k = %d, f1 = %d, "
"f2 = %d\n",
mpfr_print_rnd_mode ((mpfr_rnd_t) r),
prec, i, j, k, f1, f2);
printf ("Expected ");
mpfr_dump (sum1);
printf ("with inex = %d\n", inex1);
printf ("Got ");
mpfr_dump (sum2);
printf ("with inex = %d\n", inex2);
exit (1);
}
}
}
}
}
}
}
for (i = 0; i < 5; i++)
mpfr_clear (t[i]);
mpfr_clears (sum1, sum2, s1, s2, s3, s4, (mpfr_ptr) 0);
}
/* i * 2^(46+h) + j * 2^(45+h) + k * 2^(44+h) + f * 2^(-2),
with -1 <= i, j, k <= 1, i != 0, -3 <= f <= 3, and
* prec set up so that ulp(exact sum) = 2^0, then
* prec set up so that ulp(exact sum) = 2^(44+h) when possible,
i.e. when prec >= MPFR_PREC_MIN.
------
Some explanations:
ulp(exact sum) = 2^q means EXP(exact sum) - prec = q where prec is
the precision of the output. Thus ulp(exact sum) = 2^0 is achieved
by setting prec = EXP(s3), where s3 is the exact sum (computed with
mpfr_add's and sufficient precision). Then ulp(exact sum) = 2^(44+h)
is achieved by subtracting 44+h from prec. The loop on prec does
this. Since EXP(s3) <= 47+h, prec <= 3 at the second iteration,
thus there will be at most 2 iterations. Whether a second iteration
is done or not depends on EXP(s3), i.e. the values of the parameters,
and the value of MPFR_PREC_MIN. */
static void
check1 (int h)
{
mpfr_t sum1, sum2, s1, s2, s3, t[4];
mpfr_ptr p[4];
int i, j, k, f, prec, r, inex1, inex2;
mpfr_init2 (sum1, 47 + h);
mpfr_init2 (sum2, 47 + h);
mpfr_init2 (s1, 3);
mpfr_init2 (s2, 3);
mpfr_init2 (s3, 49 + h);
for (i = 0; i < 4; i++)
{
mpfr_init2 (t[i], 2);
p[i] = t[i];
}
for (i = -1; i <= 1; i += 2)
{
mpfr_set_si_2exp (t[0], i, 46 + h, MPFR_RNDN);
for (j = -1; j <= 1; j++)
{
mpfr_set_si_2exp (t[1], j, 45 + h, MPFR_RNDN);
inex1 = mpfr_add (s1, t[0], t[1], MPFR_RNDN);
MPFR_ASSERTN (inex1 == 0);
for (k = -1; k <= 1; k++)
{
mpfr_set_si_2exp (t[2], k, 44 + h, MPFR_RNDN);
inex1 = mpfr_add (s2, s1, t[2], MPFR_RNDN);
MPFR_ASSERTN (inex1 == 0);
for (f = -3; f <= 3; f++)
{
mpfr_set_si_2exp (t[3], f, -2, MPFR_RNDN);
inex1 = mpfr_add (s3, s2, t[3], MPFR_RNDN);
MPFR_ASSERTN (inex1 == 0);
for (prec = mpfr_get_exp (s3);
prec >= MPFR_PREC_MIN;
prec -= 44 + h)
{
mpfr_set_prec (sum1, prec);
mpfr_set_prec (sum2, prec);
RND_LOOP (r)
{
inex1 = mpfr_set (sum1, s3, (mpfr_rnd_t) r);
inex2 = mpfr_sum (sum2, p, 4, (mpfr_rnd_t) r);
MPFR_ASSERTN (mpfr_check (sum1));
MPFR_ASSERTN (mpfr_check (sum2));
if (!(mpfr_equal_p (sum1, sum2) &&
SAME_SIGN (inex1, inex2)))
{
printf ("Error in check1 on %s, prec = %d, "
"i = %d, j = %d, k = %d, f = %d, "
"h = %d\n",
mpfr_print_rnd_mode ((mpfr_rnd_t) r),
prec, i, j, k, f, h);
printf ("Expected ");
mpfr_dump (sum1);
printf ("with inex = %d\n", inex1);
printf ("Got ");
mpfr_dump (sum2);
printf ("with inex = %d\n", inex2);
exit (1);
}
}
}
}
}
}
}
for (i = 0; i < 4; i++)
mpfr_clear (t[i]);
mpfr_clears (sum1, sum2, s1, s2, s3, (mpfr_ptr) 0);
}
static void
check_more_special (void)
{
char *str[NC] = { "NaN", "+Inf", "-Inf", "+0", "-0", "+1", "-1" };
int i, r, k[NS];
mpfr_t c[NC], s[NS], sum;
mpfr_ptr p[NS];
int inex;
for (i = 0; i < NC; i++)
{
int ret;
mpfr_init2 (c[i], 8);
ret = mpfr_set_str (c[i], str[i], 0, MPFR_RNDN);
MPFR_ASSERTN (ret == 0);
}
for (i = 0; i < NS; i++)
mpfr_init2 (s[i], 8);
mpfr_init2 (sum, 8);
RND_LOOP(r)
{
i = 0;
while (1)
{
while (i < NS)
{
p[i] = c[0];
mpfr_set_nan (s[i]);
k[i++] = 0;
}
inex = mpfr_sum (sum, p, NS, (mpfr_rnd_t) r);
if (! ((MPFR_IS_NAN (sum) && MPFR_IS_NAN (s[NS-1])) ||
(mpfr_equal_p (sum, s[NS-1]) &&
MPFR_SIGN (sum) == MPFR_SIGN (s[NS-1]))) || inex != 0)
{
printf ("Error in check_more_special on %s",
mpfr_print_rnd_mode ((mpfr_rnd_t) r));
for (i = 0; i < NS; i++)
printf (" %d", k[i]);
printf (" with\n");
for (i = 0; i < NS; i++)
{
printf (" p[%d] = %s = ", i, str[k[i]]);
mpfr_dump (p[i]);
}
printf ("Expected ");
mpfr_dump (s[NS-1]);
printf ("with inex = 0\n");
printf ("Got ");
mpfr_dump (sum);
printf ("with inex = %d\n", inex);
exit (1);
}
while (k[--i] == NC-1)
if (i == 0)
goto next_rnd;
p[i] = c[++k[i]];
if (i == 0)
mpfr_set (s[i], p[i], (mpfr_rnd_t) r);
else
mpfr_add (s[i], s[i-1], p[i], (mpfr_rnd_t) r);
i++;
}
next_rnd: ;
}
for (i = 0; i < NC; i++)
mpfr_clear (c[i]);
for (i = 0; i < NS; i++)
mpfr_clear (s[i]);
mpfr_clear (sum);
}