>>> It seems we should just remove the use of register?
>>
>> I have a vague idea that it was once important to say "register" if
>> you are going to use the variable in an asm snippet that requires it
>> to be in a register. That might be wrong, or it might be obsolete
>> even if once true. We could try taking these out and seeing if the
>> buildfarm complains.
>
> We have several inline asm statements not using register despite using
> variables in a register (e.g. pg_atomic_compare_exchange_u32_impl()), so I
> wouldn't expect a problem with compilers we support.
>
> Should we make configure test for -Wregister? There's at least one additional
> use of register that we'd have to change (pg_regexec).
From a compilation perspective, "register" tells the compiler that you
cannot have a pointer on a variable, i.e. it generates an error if someone
adds something like:
void * p = ®ister_variable;
Removing the "register" declaration means that such protection would be
removed, and creating such a pointer could reduce drastically compiler
optimization opportunities.
--
Fabien.
