[Bug inline-asm/54450] Extended asm in global scope

[gjl at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=54450

--- Comment #7 from Georg-Johann Lay <gjl at gcc dot gnu.org> ---
(In reply to Eric Gallager from comment #6)
> (In reply to Marek Polacek from comment #2)
> > Probably dup of http://gcc.gnu.org/bugzilla/show_bug.cgi?id=41045
> 
> Agreed, closing as a duplicate of it
> 
> *** This bug has been marked as a duplicate of bug 41045 ***

Really?

What the OP wants is

>> void *ptr;
>>
>>   __asm__ ("my_function:\n\t"
>>            "jmp *%0\n\t" : : "r"(ptr));

Constraint "r" cannot work at toplevel, hence this PR is invalid.

What PR41045 is about is top-level asm arguments that are compiler-time
constants (constraint "n") and maybe also symbols (constraints "i" and "s").

So the initial request is only valid if the address of ptr was used (and &ptr
is CONST_INT, CONST or SYMBOL_REF etc.):

void *ptr;

__asm__ ("my_function:\n\t"
         "jmp ??? %0" : : "i" (&ptr));