Hi Paul,
On 5/3/24 2:50 PM, Paul Eggert wrote:
>> The macros for compilers who don't support GCC's builtins are
>> really clever. They don't look like they were too much fun to write
>> though. :)
>
> Actually they were fun in a twisted sort of way. My secret was to not
> work on them more than 30 minutes at a time (to prevent going
> crazy...).
Haha, nested ternary operators always hurt my brain. It would take me
much longer than you.
Also about this comment in intprops-internal.h:
/* This include file assumes that signed types are two's complement without
padding bits; the above macros have undefined behavior otherwise.
If this is a problem for you, please let us know how to fix it for your
host.
This assumption is tested by the intprops-tests module. */
If you want to check this at compile time I think this should work:
#if (−1 & 3) == 1
# error "signed magnitude"
#elif (-1 & 3) == 2
# error "one's complement"
#elif (-1 & 3) == 3
/* two's complement */
#endif
/* or */
typedef _gl_intprops_verify_twos_complement[(-1 & 3) == 3 ? 1 : -1];
Collin
