Merged vlefevre branch:

    svn merge -c-5445 .
    svn merge -r5436:HEAD .../mpfr/branches/vlefevre
* pow.c:
  - Moved the general case from mpfr_pow() to a new internal function
    mpfr_pow_general().
  - In this function (from old code), avoid unnecessary overflow test
    if the intermediate result is not an infinity (which was the case
    of underflow with non-zero result, thus not an overflow).
  - Fixed a double-rounding problem that occurred in this function in
    some underflow cases when rescaling the result.
  - Added log messages.
* mpfr-impl.h: added mpfr_pow_general prototype.
* pow_z.c:
  - The underflow case of mpfr_pow_pos_z() in rounding to nearest,
    which was incorrect, is now handled by calling mpfr_pow_general(),
    which can scale the result thus decide whether the rounded result
    should be 0 or nextabove(0). To avoid the exact cases of x^y with
    y integer (not supported by mpfr_pow_general()), rounding is done
    in precision 2 (this is also faster!).
  - Fixed underflow-related bug (case exact result = 2^(emin-2), in
    rounding to nearest).
  - Added log messages.
* pow_ui.c:
  - Swapped parameters x and y for consistency (-> y = x^n).
  - Fixed the internal overflows and underflows (which could yield
    spurious overflows/underflows and incorrect results) by using
    mpfr_pow_z.
* tests/tpow_all.c:
  - Test flags in test_others and cmpres; cmpres argument z1 can now
    be a null pointer (if unknown pure FP value, thus not tested).
  - Added a test of 2^(emin - i/4) with 0 <= i <= 12, that triggered
    the bugs mentioned above (and now fixed).

git-svn-id: svn://scm.gforge.inria.fr/svn/mpfr/trunk@5505 280ebfd0-de03-0410-8827-d642c229c3f4

1 files changed, 3 insertions, 0 deletions

diff --git a/mpfr-impl.h b/mpfr-impl.h
index a1f974c69..a23a4f4ff 100644
--- a/mpfr-impl.h
+++ b/mpfr-impl.h
@@ -1565,6 +1565,9 @@ __MPFR_DECLSPEC int mpfr_exp_2 _MPFR_PROTO ((mpfr_ptr, mpfr_srcptr,mp_rnd_t));
 __MPFR_DECLSPEC int mpfr_exp_3 _MPFR_PROTO ((mpfr_ptr, mpfr_srcptr,mp_rnd_t));
 __MPFR_DECLSPEC int mpfr_powerof2_raw _MPFR_PROTO ((mpfr_srcptr));
 
+__MPFR_DECLSPEC int mpfr_pow_general _MPFR_PROTO ((mpfr_ptr, mpfr_srcptr,
+                           mpfr_srcptr, mp_rnd_t, int, mpfr_save_expo_t *));
+
 __MPFR_DECLSPEC void mpfr_setmax _MPFR_PROTO ((mpfr_ptr, mp_exp_t));
 __MPFR_DECLSPEC void mpfr_setmin _MPFR_PROTO ((mpfr_ptr, mp_exp_t));