]> Savannah Git Hosting - gnulib.git/commit
intprops: tune INT_NEGATE_OVERFLOW for GCC 5 and 6
authorPaul Eggert <eggert@cs.ucla.edu>
Tue, 30 Aug 2016 19:29:21 +0000 (12:29 -0700)
committerPaul Eggert <eggert@cs.ucla.edu>
Tue, 30 Aug 2016 19:30:49 +0000 (12:30 -0700)
commit39fca95053926d63f2ffed3dd64dc41a7d35b767
tree645aa3ce9485654e42d711920f14655dd5edb4a0
parent5d856f70e9515ea5288d9cc9b15996af41bf4f7f
intprops: tune INT_NEGATE_OVERFLOW for GCC 5 and 6

* lib/intprops.h (INT_NEGATE_OVERFLOW): Tune for platforms like
GCC 5 and 6 that have __builtin_sub_overflow but not
__builtin_sub_overflow_p.  With the recent changes, these
platforms are a tiny bit faster with the INT_NEGATE_RANGE_OVERFLOW
implementation than with INT_SUBTRACT_OVERFLOW implementation,
since the former needs just one runtime comparison whereas the
latter needs two.
ChangeLog
lib/intprops.h