make it clear that we don't propagate the sign bit in mpfr_get_d and mpfr_set_d

and similar functions for binary32, decimal64 and binary128


git-svn-id: https://scm.gforge.inria.fr/anonscm/svn/mpfr/trunk@14296 280ebfd0-de03-0410-8827-d642c229c3f4

1 files changed, 4 insertions, 2 deletions

diff --git a/doc/mpfr.texi b/doc/mpfr.texi
index b6c502646..3e0f05ebd 100644
--- a/doc/mpfr.texi
+++ b/doc/mpfr.texi
@@ -1420,7 +1420,8 @@ to use @code{mpfr_set_float128}, one should define the macro
 If the system does not support the IEEE@tie{}754 standard,
 @code{mpfr_set_flt}, @code{mpfr_set_d}, @code{mpfr_set_ld},
 @code{mpfr_set_decimal64} and @code{mpfr_set_decimal128}
-might not preserve the signed zeros.
+might not preserve the signed zeros
+(and in any case they don't preserve the sign bit of NaN).
 The @code{mpfr_set_decimal64} and @code{mpfr_set_decimal128}
 functions are built only with the configure
 option @samp{--enable-decimal-float}, and when the compiler or
@@ -1608,7 +1609,8 @@ Convert @var{op} to a @code{float} (respectively @code{double},
 @code{long double}, @code{_Decimal64}, or @code{_Decimal128})
 using the rounding mode @var{rnd}.
 If @var{op} is NaN, some fixed NaN (either quiet or signaling) or the result
-of 0.0/0.0 is returned. If @var{op} is @pom{}Inf, an infinity of the same
+of 0.0/0.0 is returned (the sign bit is not preserved).
+If @var{op} is @pom{}Inf, an infinity of the same
 sign or the result of @pom{}1.0/0.0 is returned. If @var{op} is zero, these
 functions return a zero, trying to preserve its sign, if possible.
 The @code{mpfr_get_float128}, @code{mpfr_get_decimal64} and