diff options
| -rw-r--r-- | doc/mpfr.texi | 4 | ||||
| -rw-r--r-- | src/compound.c | 12 | ||||
| -rw-r--r-- | tests/tcompound.c | 12 |
3 files changed, 15 insertions, 13 deletions
diff --git a/doc/mpfr.texi b/doc/mpfr.texi index f87600ca0..a00435dd2 100644 --- a/doc/mpfr.texi +++ b/doc/mpfr.texi @@ -2268,8 +2268,8 @@ used for @code{pow}. @deftypefun int mpfr_compound (mpfr_t @var{rop}, mpfr_t @var{op}, long int @var{n}, mpfr_rnd_t @var{rnd}) Set @var{rop} to the power @var{n} of one plus @var{op}, following IEEE@tie{}754-2019 for the special cases and exceptions. -When @var{n} is zero and @var{op} is larger or equal @minus{}1, -@var{rop} is set to 1 (IEEE@tie{}754-2019 also allows NaN)@. +When @var{n} is zero and @var{op} is NaN or greater or equal to @minus{}1, +@var{rop} is set to 1. @end deftypefun @deftypefun int mpfr_cos (mpfr_t @var{rop}, mpfr_t @var{op}, mpfr_rnd_t @var{rnd}) diff --git a/src/compound.c b/src/compound.c index 55a9e9205..0e63e7cb3 100644 --- a/src/compound.c +++ b/src/compound.c @@ -69,15 +69,15 @@ mpfr_compound (mpfr_ptr y, mpfr_srcptr x, long n, mpfr_rnd_t rnd_mode) /* Special cases */ if (MPFR_IS_SINGULAR (x)) { - if (MPFR_IS_NAN (x) || (MPFR_IS_INF (x) && MPFR_SIGN (x) < 0)) + if (n == 0 || MPFR_IS_ZERO (x)) { - MPFR_SET_NAN (y); - MPFR_RET_NAN; + /* (1+Inf)^0 = 1 and (1+x)^0 = 1, even for x = NaN */ + return mpfr_set_ui (y, 1, rnd_mode); } - else if (n == 0 || MPFR_IS_ZERO (x)) + else if (MPFR_IS_NAN (x) || (MPFR_IS_INF (x) && MPFR_SIGN (x) < 0)) { - /* (1+Inf)^0 = 1 and (1+x)^0 = 1 */ - return mpfr_set_ui (y, 1, rnd_mode); + MPFR_SET_NAN (y); + MPFR_RET_NAN; } else if (MPFR_IS_INF (x)) /* x = +Inf */ { diff --git a/tests/tcompound.c b/tests/tcompound.c index 3ac18ceaa..7c41af0aa 100644 --- a/tests/tcompound.c +++ b/tests/tcompound.c @@ -55,13 +55,15 @@ check_ieee754 (void) exit (1); } - /* compound(x,0) = 1 for x >= -1 or x = qNaN */ - for (i = -1; i <= 2; i++) + /* compound(x,0) = 1 for x >= -1 or x = NaN */ + for (i = -2; i <= 2; i++) { - if (i != 2) - mpfr_set_si (x, i, MPFR_RNDN); - else + if (i == -2) + mpfr_set_nan (x); + else if (i == 2) mpfr_set_inf (x, 1); + else + mpfr_set_si (x, i, MPFR_RNDN); mpfr_compound (y, x, 0, MPFR_RNDN); if (mpfr_cmp_ui (y, 1) != 0) { |