diff options
| -rw-r--r-- | src/sub1.c | 8 |
1 files changed, 7 insertions, 1 deletions
diff --git a/src/sub1.c b/src/sub1.c index 1e9fd72ae..69a2871e1 100644 --- a/src/sub1.c +++ b/src/sub1.c @@ -210,7 +210,13 @@ mpfr_sub1 (mpfr_ptr a, mpfr_srcptr b, mpfr_srcptr c, mpfr_rnd_t rnd_mode) if (MPFR_UNLIKELY (exp_a > __gmpfr_emax)) return mpfr_overflow (a, rnd_mode, MPFR_SIGN (a)); if (MPFR_UNLIKELY (exp_a < __gmpfr_emin)) - goto underflow; + { + if (rnd_mode == MPFR_RNDN && + (exp_a < __gmpfr_emin - 1 || + (inexact * MPFR_INT_SIGN (a) >= 0 && mpfr_powerof2_raw (a)))) + rnd_mode = MPFR_RNDZ; + return mpfr_underflow (a, rnd_mode, MPFR_SIGN(a)); + } MPFR_SET_EXP (a, exp_a); MPFR_RET (inexact); } |