diff options
| -rw-r--r-- | atan.c | 13 | ||||
| -rw-r--r-- | tests/tatan.c | 14 |
2 files changed, 21 insertions, 6 deletions
@@ -176,7 +176,6 @@ mpfr_atan (mpfr_ptr atan, mpfr_srcptr x, mp_rnd_t rnd_mode) mpfr_t arctgt, sk, tmp, tmp2; mpz_t ukz; int comparaison, inexact, inexact2; - mp_exp_t estimated_delta; mp_prec_t prec, realprec; mp_exp_t exptol; int i, n0, oldn0; @@ -242,12 +241,12 @@ mpfr_atan (mpfr_ptr atan, mpfr_srcptr x, mp_rnd_t rnd_mode) } realprec = MPFR_PREC (atan) + MPFR_INT_CEIL_LOG2 (MPFR_PREC (atan)) + 4; - if (MPFR_PREC (atan) + 5 > MPFR_PREC (x) && MPFR_GET_EXP (x) < 0) + /* if (MPFR_PREC (atan) + 5 > MPFR_PREC (x) && MPFR_GET_EXP (x) < 0) { mpfr_uexp_t ue = (mpfr_uexp_t) (-MPFR_GET_EXP (x)); if (realprec < 2*ue + 5) realprec = 2*ue + 5; - } + } */ prec = realprec + BITS_PER_MP_LIMB; MPFR_SAVE_EXPO_MARK (expo); @@ -266,10 +265,11 @@ mpfr_atan (mpfr_ptr atan, mpfr_srcptr x, mp_rnd_t rnd_mode) for (;;) { /* n0 = ceil(log2(realprec + 2 + 1+ln(2.4)/ln(2))) */ - n0 = MPFR_INT_CEIL_LOG2 (realprec + 2 + 3); + mp_prec_t sup = MAX (-MPFR_GET_EXP (xp), 0) + 2; + n0 = MPFR_INT_CEIL_LOG2 (realprec + sup + 3); MPFR_ASSERTD (3*n0 > 2); - estimated_delta = 1 + 2 + MPFR_INT_CEIL_LOG2 (3*n0-2); - prec = realprec + estimated_delta; + prec = realprec + 1 + sup + MPFR_INT_CEIL_LOG2 (3*n0-2); + /* printf ("Prec=%lu realprec=%lu\n", prec, realprec); */ /* Initialisation */ mpfr_set_prec (sk, prec); @@ -324,6 +324,7 @@ mpfr_atan (mpfr_ptr atan, mpfr_srcptr x, mp_rnd_t rnd_mode) mpz_mul (ukz, ukz, ukz); mpz_neg (ukz, ukz); mpfr_atan_aux (tmp2, ukz, 2*twopoweri, n0 - i, tabz, tabi); + mpfr_mul (tmp2, tmp2, tmp, GMP_RNDN); /* Addition and iteration */ diff --git a/tests/tatan.c b/tests/tatan.c index 4b46661da..67f703a43 100644 --- a/tests/tatan.c +++ b/tests/tatan.c @@ -166,6 +166,20 @@ special (void) mpfr_atan (x, x, GMP_RNDN); MPFR_ASSERTN (MPFR_IS_NEG (x)); + /* Test regression */ + mpfr_set_prec (x, 48); + mpfr_set_prec (y, 48); + mpfr_set_str_binary (x, "1.11001110010000011111100000010000000000000000000e-19"); + mpfr_atan (y, x, GMP_RNDD); + if (mpfr_cmp_str (y, "0.111001110010000011111100000001111111110000010011E-18", 2, GMP_RNDN)) + { + printf ("Error in mpfr_atan (4)\n"); + printf ("Input 1.11001110010000011111100000010000000000000000000e-19 [prec=48]\n"); + printf ("Expected 0.111001110010000011111100000001111111110000010011E-18\n"); + printf ("Got "); mpfr_dump (y); + exit (1); + } + mpfr_clear (x); mpfr_clear (y); mpfr_clear (z); |