diff options
Diffstat (limited to 'tests/tsub.c')
| -rw-r--r-- | tests/tsub.c | 353 |
1 files changed, 353 insertions, 0 deletions
diff --git a/tests/tsub.c b/tests/tsub.c index b7a304901..452ce4588 100644 --- a/tests/tsub.c +++ b/tests/tsub.c @@ -1159,6 +1159,358 @@ bug20180217 (void) } } +/* Tests on UBF. + * + * Note: mpfr_sub1sp will never be used as it does not support UBF. + * Thus there is no need to generate tests for both mpfr_sub1 and + * mpfr_sub1sp. + * + * Note that mpfr_sub1 has a special branch "c small", where the second + * argument c is sufficiently smaller than the ulp of the first argument + * and the ulp of the result: MAX (aq, bq) + 2 <= diff_exp. + * Tests should be done for both the main branch and this special branch + * when this makes sense. + */ +#define REXP 1024 + +static void test_ubf_aux (void) +{ + mpfr_ubf_t x[11]; + mpfr_ptr p[11]; + int ex[11]; + mpfr_t ee, y, z, w; + int i, j, k, neg, inexact, rnd; + const int kn = 2; + mpfr_exp_t e[] = + { MPFR_EXP_MIN, MPFR_EMIN_MIN, -REXP, 0, + REXP, MPFR_EMAX_MAX, MPFR_EXP_MAX }; + + mpfr_init2 (ee, sizeof (mpfr_exp_t) * CHAR_BIT); + mpfr_inits2 (64, y, z, (mpfr_ptr) 0); + mpfr_init2 (w, 2); + + for (i = 0; i < 11; i++) + p[i] = (mpfr_ptr) x[i]; + + /* exact zero result, with small and large exponents */ + for (i = 0; i < 2; i++) + { + mpfr_init2 (p[i], 5 + (randlimb () % 128)); + mpfr_set_ui (p[i], 17, MPFR_RNDN); + mpz_init (MPFR_ZEXP (p[i])); + MPFR_SET_UBF (p[i]); + } + for (j = 0; j < numberof (e); j++) + { + inexact = mpfr_set_exp_t (ee, e[j], MPFR_RNDN); + MPFR_ASSERTD (inexact == 0); + inexact = mpfr_get_z (MPFR_ZEXP (p[0]), ee, MPFR_RNDN); + MPFR_ASSERTD (inexact == 0); + mpz_sub_ui (MPFR_ZEXP (p[0]), MPFR_ZEXP (p[0]), kn); + + for (k = -kn; k <= kn; k++) + { + /* exponent: e[j] + k, with |k| <= kn */ + mpz_set (MPFR_ZEXP (p[1]), MPFR_ZEXP (p[0])); + + for (neg = 0; neg <= 1; neg++) + { + RND_LOOP (rnd) + { + /* Note: x[0] and x[1] are equal MPFR numbers, but do not + test mpfr_sub with arg2 == arg3 as pointers in order to + skip potentially optimized mpfr_sub code. */ + inexact = mpfr_sub (z, p[0], p[1], (mpfr_rnd_t) rnd); + if (inexact != 0 || MPFR_NOTZERO (z) || + (rnd != MPFR_RNDD ? MPFR_IS_NEG (z) : MPFR_IS_POS (z))) + { + printf ("Error 1 in test_ubf for exact zero result: " + "j=%d k=%d neg=%d, rnd=%s\nGot ", j, k, neg, + mpfr_print_rnd_mode ((mpfr_rnd_t) rnd)); + mpfr_dump (z); + printf ("inexact = %d\n", inexact); + exit (1); + } + } + + for (i = 0; i < 2; i++) + MPFR_CHANGE_SIGN (p[i]); + } + + mpz_add_ui (MPFR_ZEXP (p[0]), MPFR_ZEXP (p[0]), 1); + } + } + for (i = 0; i < 2; i++) + { + MPFR_UBF_CLEAR_EXP (p[i]); + mpfr_clear (p[i]); + } + + /* Up to a given exponent (for the result) and sign, test: + * (t + .11010) - (t + .00001) = .11001 + * (t + 8) - (t + 111.00111) = .11001 + * where t = 0 or a power of 2, e.g. 2^200. Test various exponents + * (including those near the underflow/overflow boundaries) so that + * the subtraction yields a normal number, an overflow or an underflow. + * In MPFR_RNDA, also test with a 2-bit precision target, as this + * yields an exponent change. + * + * Also test the "MAX (aq, bq) + 2 <= diff_exp" branch of sub1.c with + * .1 - epsilon (possible decrease of the exponent) and .111 - epsilon + * in precision 2 (possible increase of the exponent). The first test + * triggers a possible decrease of the exponent (see bug fixed in r13806). + * The second test triggers a possible increase of the exponent (see the + * "exp_a != MPFR_EXP_MAX" test to avoid an integer overflow). + */ + for (i = 0; i < 8; i++) + { + static int v[4] = { 26, 1, 256, 231 }; + + mpfr_init2 (p[i], i < 4 ? 5 + (randlimb () % 128) : 256); + if (i < 4) + mpfr_set_si_2exp (p[i], v[i], -5, MPFR_RNDN); + else + { + mpfr_set_si_2exp (p[i], 1, 200, MPFR_RNDN); + mpfr_add (p[i], p[i], p[i-4], MPFR_RNDN); + } + ex[i] = mpfr_get_exp (p[i]) + 5; + MPFR_ASSERTD (ex[i] >= 0); + } + mpfr_inits2 (3, p[8], p[9], p[10], (mpfr_ptr) 0); + mpfr_set_si_2exp (p[8], 1, 0, MPFR_RNDN); + ex[8] = 5; + mpfr_set_si_2exp (p[9], 1, 0, MPFR_RNDN); /* will be epsilon */ + ex[9] = 0; + mpfr_set_si_2exp (p[10], 7, 0, MPFR_RNDN); + ex[10] = 5; + + for (i = 0; i < 11; i++) + { + mpz_init (MPFR_ZEXP (p[i])); + MPFR_SET_UBF (p[i]); + } + + for (j = 0; j < numberof (e); j++) + { + inexact = mpfr_set_exp_t (ee, e[j], MPFR_RNDN); + MPFR_ASSERTD (inexact == 0); + inexact = mpfr_get_z (MPFR_ZEXP (p[0]), ee, MPFR_RNDN); + MPFR_ASSERTD (inexact == 0); + for (i = 1; i < 11; i++) + mpz_set (MPFR_ZEXP (p[i]), MPFR_ZEXP (p[0])); + for (i = 0; i < 11; i++) + { + mpz_add_ui (MPFR_ZEXP (p[i]), MPFR_ZEXP (p[i]), ex[i]); + mpz_sub_ui (MPFR_ZEXP (p[i]), MPFR_ZEXP (p[i]), 5 + kn); + } + mpz_sub_ui (MPFR_ZEXP (p[9]), MPFR_ZEXP (p[9]), 256); + for (k = -kn; k <= kn; k++) + { + for (neg = 0; neg <= 1; neg++) + { + int sign = neg ? -1 : 1; + + RND_LOOP (rnd) + for (i = 0; i <= 10; i += 2) + { + mpfr_exp_t e0; + mpfr_flags_t flags, flags_y; + int inex_y; + + if (i >= 8) + { + int d; + + e0 = MPFR_UBF_GET_EXP (p[i]); + if (e0 < MPFR_EXP_MIN + 3) + e0 += 3; + + if (rnd == MPFR_RNDN) + d = i == 8 ? (e0 == __gmpfr_emin - 1 ? 3 : 4) : 6; + else if (MPFR_IS_LIKE_RNDZ (rnd, neg)) + d = i == 8 ? 3 : 6; + else + d = i == 8 ? 4 : 8; + + mpfr_clear_flags (); + inex_y = mpfr_set_si_2exp (w, sign * d, e0 - 3, + (mpfr_rnd_t) rnd); + flags_y = __gmpfr_flags | MPFR_FLAGS_INEXACT; + if (inex_y == 0) + inex_y = rnd == MPFR_RNDN ? + sign * (i == 8 ? 1 : -1) : + MPFR_IS_LIKE_RNDD ((mpfr_rnd_t) rnd, sign) ? + -1 : 1; + mpfr_set (y, w, MPFR_RNDN); + + mpfr_clear_flags (); + inexact = mpfr_sub (w, p[i], p[9], (mpfr_rnd_t) rnd); + flags = __gmpfr_flags; + + /* For MPFR_RNDF, only do a basic test. */ + MPFR_ASSERTN (mpfr_check (w)); + if (rnd == MPFR_RNDF) + continue; + + goto testw; + } + + mpfr_clear_flags (); + inexact = mpfr_sub (z, p[i], p[i+1], (mpfr_rnd_t) rnd); + flags = __gmpfr_flags; + + /* For MPFR_RNDF, only do a basic test. */ + MPFR_ASSERTN (mpfr_check (z)); + if (rnd == MPFR_RNDF) + continue; + + e0 = MPFR_UBF_GET_EXP (p[0]); + + if (e0 < __gmpfr_emin) + { + mpfr_rnd_t r = + rnd == MPFR_RNDN && e0 < __gmpfr_emin - 1 ? + MPFR_RNDZ : (mpfr_rnd_t) rnd; + flags_y = MPFR_FLAGS_UNDERFLOW | MPFR_FLAGS_INEXACT; + inex_y = mpfr_underflow (y, r, sign); + } + else if (e0 > __gmpfr_emax) + { + flags_y = MPFR_FLAGS_OVERFLOW | MPFR_FLAGS_INEXACT; + inex_y = mpfr_overflow (y, (mpfr_rnd_t) rnd, sign); + } + else + { + mpfr_set_si_2exp (y, sign * 25, e0 - 5, MPFR_RNDN); + flags_y = 0; + inex_y = 0; + } + + if (flags != flags_y || + ! SAME_SIGN (inexact, inex_y) || + ! mpfr_equal_p (y, z)) + { + printf ("Error 2 in test_ubf with " + "j=%d k=%d neg=%d i=%d rnd=%s\n", + j, k, neg, i, + mpfr_print_rnd_mode ((mpfr_rnd_t) rnd)); + printf ("emin=%" MPFR_EXP_FSPEC "d " + "emax=%" MPFR_EXP_FSPEC "d\n", + (mpfr_eexp_t) __gmpfr_emin, + (mpfr_eexp_t) __gmpfr_emax); + printf ("b = "); + mpfr_dump (p[i]); + printf ("c = "); + mpfr_dump (p[i+1]); + printf ("Expected "); + mpfr_dump (y); + printf ("with inex = %d and flags =", inex_y); + flags_out (flags_y); + printf ("Got "); + mpfr_dump (z); + printf ("with inex = %d and flags =", inexact); + flags_out (flags); + exit (1); + } + + /* Do the following 2-bit precision test only in RNDA. */ + if (rnd != MPFR_RNDA) + continue; + + mpfr_clear_flags (); + inexact = mpfr_sub (w, p[i], p[i+1], MPFR_RNDA); + flags = __gmpfr_flags; + if (e0 < MPFR_EXP_MAX) + e0++; + + if (e0 < __gmpfr_emin) + { + flags_y = MPFR_FLAGS_UNDERFLOW | MPFR_FLAGS_INEXACT; + inex_y = mpfr_underflow (y, MPFR_RNDA, sign); + } + else if (e0 > __gmpfr_emax) + { + flags_y = MPFR_FLAGS_OVERFLOW | MPFR_FLAGS_INEXACT; + inex_y = mpfr_overflow (y, MPFR_RNDA, sign); + } + else + { + mpfr_set_si_2exp (y, sign, e0 - 1, MPFR_RNDN); + flags_y = MPFR_FLAGS_INEXACT; + inex_y = sign; + } + + testw: + if (flags != flags_y || + ! SAME_SIGN (inexact, inex_y) || + ! mpfr_equal_p (y, w)) + { + printf ("Error 3 in test_ubf with " + "j=%d k=%d neg=%d i=%d rnd=%s\n", + j, k, neg, i, + mpfr_print_rnd_mode ((mpfr_rnd_t) rnd)); + printf ("emin=%" MPFR_EXP_FSPEC "d " + "emax=%" MPFR_EXP_FSPEC "d\n", + (mpfr_eexp_t) __gmpfr_emin, + (mpfr_eexp_t) __gmpfr_emax); + printf ("b = "); + mpfr_dump (p[i]); + printf ("c = "); + mpfr_dump (p[i <= 8 ? i+1 : 9]); + printf ("Expected "); + /* Set y to a 2-bit precision just for the output. + Since we exit, this will have no other effect. */ + mpfr_prec_round (y, 2, MPFR_RNDA); + mpfr_dump (y); + printf ("with inex = %d and flags =", inex_y); + flags_out (flags_y); + printf ("Got "); + mpfr_dump (w); + printf ("with inex = %d and flags =", inexact); + flags_out (flags); + exit (1); + } + } + + for (i = 0; i < 11; i++) + MPFR_CHANGE_SIGN (p[i]); + } + + for (i = 0; i < 11; i++) + mpz_add_ui (MPFR_ZEXP (p[i]), MPFR_ZEXP (p[i]), 1); + } + } + for (i = 0; i < 11; i++) + { + MPFR_UBF_CLEAR_EXP (p[i]); + mpfr_clear (p[i]); + } + + mpfr_clears (ee, y, z, w, (mpfr_ptr) 0); +} + +/* Run the tests on UBF with the maximum exponent range and with a + reduced exponent range. */ +static void test_ubf (void) +{ + mpfr_exp_t emin, emax; + + emin = mpfr_get_emin (); + emax = mpfr_get_emax (); + + set_emin (MPFR_EMIN_MIN); + set_emax (MPFR_EMAX_MAX); + test_ubf_aux (); + + set_emin (-REXP); + set_emax (REXP); + test_ubf_aux (); + + set_emin (emin); + set_emax (emax); +} + #define TEST_FUNCTION test_sub #define TWO_ARGS #define RAND_FUNCTION(x) mpfr_random2(x, MPFR_LIMB_SIZE (x), randlimb () % 100, RANDS) @@ -1188,6 +1540,7 @@ main (void) for (i=0; i<50; i++) check_two_sum (p); test_generic (MPFR_PREC_MIN, 800, 100); + test_ubf (); tests_end_mpfr (); return 0; |