diff options
Diffstat (limited to 'src/strtofr.c')
| -rw-r--r-- | src/strtofr.c | 13 |
1 files changed, 8 insertions, 5 deletions
diff --git a/src/strtofr.c b/src/strtofr.c index 67f5caa62..a1904cc04 100644 --- a/src/strtofr.c +++ b/src/strtofr.c @@ -743,11 +743,14 @@ parsed_string_to_mpfr (mpfr_t x, struct parsed_string *pstr, mpfr_rnd_t rnd) of the pstr_size most significant digits of pstr->mant, with equality in case exact is non-zero. */ - /* test if rounding is possible, and if so exit the loop */ - if (exact || mpfr_can_round_raw (result, ysize, - (pstr->negative) ? -1 : 1, - ysize_bits - err - 1, - MPFR_RNDN, rnd, MPFR_PREC(x))) + /* test if rounding is possible, and if so exit the loop. + Note: we also need to be able to determine the correct ternary value, + thus we use the MPFR_PREC(x) + (rnd == MPFR_RNDN) trick. + For example if result = xxx...xxx111...111 and rnd = RNDN, + then we know the correct rounding is xxx...xx(x+1), but we cannot know + the correct ternary value. */ + if (exact || mpfr_round_p (result, ysize, ysize_bits - err - 1, + MPFR_PREC(x) + (rnd == MPFR_RNDN))) break; next_loop: |