> Why this? What was wrong with the previous formula > > #define OFFSET_MAX \ > ((((OFFSET)1 << (sizeof (OFFSET) * CHAR_BIT - 2)) - 1) * 2 + 1) > > (OFFSET being a signed type)?
The same formula is being used in lib/intprops.h:50: : ((((t) 1 << (TYPE_WIDTH (t) - 2)) - 1) * 2 + 1))) m4/longlong.m4:34: (1LL << (sizeof (long long int) * CHAR_BIT - 2)) m4/mktime.m4:223: : ((((time_t) 1 << (sizeof (time_t) * CHAR_BIT - 2)) - 1) m4/nanosleep.m4:59: : ((((t) 1 << (sizeof (t) * CHAR_BIT - 2)) - 1) * 2 + 1))) m4/stdint.m4:167: : ((((t) 1 << (sizeof (t) * CHAR_BIT - 2)) - 1) * 2 + 1))) Also in the documentation [1] we write "Gnulib code makes the following additional assumptions: ... There are no “holes” in integer values: all the bits of an integer contribute to its value in the usual way." Bruno [1] https://www.gnu.org/software/gnulib/manual/html_node/Other-portability-assumptions.html
