Mercurial > gnulib
changeset 18392:8f2f9412df5a
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.
| author | Paul Eggert <eggert@cs.ucla.edu> |
|---|---|
| date | Tue, 30 Aug 2016 12:29:21 -0700 |
| parents | e33d68885d8a |
| children | 73762a329243 |
| files | ChangeLog lib/intprops.h |
| diffstat | 2 files changed, 10 insertions(+), 1 deletions(-) [+] |
line wrap: on
line diff
--- a/ChangeLog Tue Aug 30 08:23:44 2016 -0700 +++ b/ChangeLog Tue Aug 30 12:29:21 2016 -0700 @@ -1,5 +1,14 @@ 2016-08-30 Paul Eggert <eggert@cs.ucla.edu> + 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. + strverscmp: sync with glibc Although this doesn't exactly synchronize with glibc byte-for-byte, it makes the code behave the same as glibc.
--- a/lib/intprops.h Tue Aug 30 08:23:44 2016 -0700 +++ b/lib/intprops.h Tue Aug 30 12:29:21 2016 -0700 @@ -330,7 +330,7 @@ _GL_BINARY_OP_OVERFLOW (a, b, _GL_ADD_OVERFLOW) #define INT_SUBTRACT_OVERFLOW(a, b) \ _GL_BINARY_OP_OVERFLOW (a, b, _GL_SUBTRACT_OVERFLOW) -#if _GL_HAS_BUILTIN_OVERFLOW || _GL_HAS_BUILTIN_OVERFLOW_P +#if _GL_HAS_BUILTIN_OVERFLOW_P # define INT_NEGATE_OVERFLOW(a) INT_SUBTRACT_OVERFLOW (0, a) #else # define INT_NEGATE_OVERFLOW(a) \