diff options
| -rw-r--r-- | doc/mpfr.texi | 17 | ||||
| -rw-r--r-- | src/mpfr-impl.h | 4 | ||||
| -rw-r--r-- | src/set_exp.c | 4 |
3 files changed, 19 insertions, 6 deletions
diff --git a/doc/mpfr.texi b/doc/mpfr.texi index 771f16989..dc1b5efc6 100644 --- a/doc/mpfr.texi +++ b/doc/mpfr.texi @@ -2835,10 +2835,9 @@ infinity or zero is undefined. @end deftypefun @deftypefun int mpfr_set_exp (mpfr_t @var{x}, mpfr_exp_t @var{e}) -Set the exponent of @var{x} if @var{e} is in the current exponent range, -and return 0 (even if @var{x} is not a non-zero ordinary number); -otherwise, return a non-zero value. -The significand is assumed to be in [1/2,1). +Set the exponent of @var{x} to @var{e} if @var{x} is a non-zero ordinary +number and @var{e} is in the current exponent range, and return 0; +otherwise, return a non-zero value (@var{x} is not changed). @end deftypefun @deftypefun int mpfr_signbit (mpfr_t @var{op}) @@ -3646,6 +3645,16 @@ Note: this function has been renamed to @code{mpfr_get_z_2exp} in MPFR 3.0, but @code{mpfr_get_z_exp} is still available for compatibility reasons. +@item @code{mpfr_set_exp} changed in MPFR 3.2. +Before MPFR 3.2, the exponent was set whatever the contents of the MPFR +object in argument. In practice, this could be useful as a low-level +function when the MPFR number was being constructed by setting the fields +of its internal structure, but the API does not provide a way to do this +except by using internals. Thus, for the API, this behavior was useless +and could quickly lead to undefined behavior due to the fact that the +generated value could have an invalid format if the MPFR object contained +a special value (NaN, infinity or zero). + @item @code{mpfr_strtofr} changed in MPFR 2.3.1 and MPFR 2.4. This was actually a bug fix since the code and the documentation did not match. But both were changed in order to have a more consistent diff --git a/src/mpfr-impl.h b/src/mpfr-impl.h index 569bb8336..eee6afae2 100644 --- a/src/mpfr-impl.h +++ b/src/mpfr-impl.h @@ -784,7 +784,9 @@ typedef intmax_t mpfr_eexp_t; #ifdef MPFR_EXP_CHECK # define MPFR_GET_EXP(x) (mpfr_get_exp) (x) -# define MPFR_SET_EXP(x, exp) MPFR_ASSERTN (!mpfr_set_exp ((x), (exp))) +# define MPFR_SET_EXP(x, exp) (MPFR_ASSERTN ((exp) >= __gmpfr_emin && \ + (exp) <= __gmpfr_emax), \ + (void) (MPFR_EXP (x) = (exp))) # define MPFR_SET_INVALID_EXP(x) ((void) (MPFR_EXP (x) = MPFR_EXP_INVALID)) #else # define MPFR_GET_EXP(x) MPFR_EXP (x) diff --git a/src/set_exp.c b/src/set_exp.c index 22322ea32..42defe268 100644 --- a/src/set_exp.c +++ b/src/set_exp.c @@ -25,7 +25,9 @@ http://www.gnu.org/licenses/ or write to the Free Software Foundation, Inc., int mpfr_set_exp (mpfr_ptr x, mpfr_exp_t exponent) { - if (MPFR_LIKELY (exponent >= __gmpfr_emin && exponent <= __gmpfr_emax)) + if (MPFR_LIKELY (MPFR_IS_PURE_FP (x) && + exponent >= __gmpfr_emin && + exponent <= __gmpfr_emax)) { MPFR_EXP(x) = exponent; /* do not use MPFR_SET_EXP of course... */ return 0; |