[src/get_d128.c] For the special values, avoid double to _Decimal128

conversions, as for such conversions, GCC generates from 2 to 3 MB in
the shared library when the decimal encoding is BID, and there will be
no fix in GCC:
  https://gcc.gnu.org/bugzilla/show_bug.cgi?id=96173
We now use computations on _Decimal128 constants directly, which could
thus be done at compile time. We expect no problems similar to double,
as the _Decimal128 implementation should follow the IEEE 754 rules.
This commit should avoid a large part of the problem reported at:
  https://gforge.inria.fr/tracker/?func=detail&atid=619&aid=21849&group_id=136
(merged changesets r14087-14088 from the trunk)

git-svn-id: svn://scm.gforge.inria.fr/svn/mpfr/branches/4.1@14094 280ebfd0-de03-0410-8827-d642c229c3f4

1 files changed, 3 insertions, 4 deletions

diff --git a/src/get_d128.c b/src/get_d128.c
index 69b1d2064..c849f6c29 100644
--- a/src/get_d128.c
+++ b/src/get_d128.c
@@ -40,22 +40,21 @@ https://www.gnu.org/licenses/ or write to the Free Software Foundation, Inc.,
 static _Decimal128
 get_decimal128_nan (void)
 {
-  return (_Decimal128) MPFR_DBL_NAN;
+  return 0.0dl / 0.0dl;
 }
 
 /* construct the decimal128 Inf with given sign */
 static _Decimal128
 get_decimal128_inf (int negative)
 {
-  return (_Decimal128) (negative ? MPFR_DBL_INFM : MPFR_DBL_INFP);
+  return negative ? - 1.0dl / 0.0dl : 1.0dl / 0.0dl;
 }
 
 /* construct the decimal128 zero with given sign */
 static _Decimal128
 get_decimal128_zero (int negative)
 {
-  _Decimal128 zero = 0;
-  return (_Decimal128) (negative ? -zero : zero);
+  return negative ? - 0.0dl : 0.0dl;
 }
 
 /* construct the decimal128 smallest non-zero with given sign: