Simon Kagstrom writes:
> At Wed, 23 Aug 2006 12:51:33 +0100,
> Andrew Haley wrote:
> > > But I cannot quite understand where the difference comes from. What I
> > > would like the original macro to generate is:
> > >
> > > .set push
> > > .set noreorder
> > > .long 0xfffe0009
> > > .short 0xffff
> > > .short 9
> > > .set pop
> >
> > So why not do that, then? In a single asm.
>
> I would love to, but I can't. That's what my original problem with
> __builtin_constant_p was. My original syscall macro indeed looked like
> this:
>
> #define _syscall1(type,name,atype,a) \
> type name(atype a) { \
> register unsigned long __v0 asm("$2"); \
> \
> __asm__ volatile ( \
> ".set push" \
> ".set noreorder " \
> ".long %1" \
> ".long %2" \
> ".short 0xffff #" #name " " \
> ".short %3" \
> ".set pop" \
> : "=&r" (__v0) \
> :"r?i" (__builtin_constant_p(a) ? 0xfffd : 0xfffe), "r?i" (a), \
> "i" (__NR_##name) ); \
> \
> return (type) __v0; \
> }
>
> and it didn't work because of the
>
> :"r?i" (__builtin_constant_p(a) ? 0xfffd : 0xfffe), "r?i" (a), \
>
> part.
But that __builtin_constant_p problem was because you put the call to
it in a function, not because of any other issues. Why not put the
*whole lot* in a macro? There's no need to break it into separate
functions. Why was the function you had before not something like
#define puts(string)
({ \
register unsigned long __v0 asm ("$2"); \
__asm__ volatile (".set push\n.set noreorder\n"); \
if (__builtin_constant_p (string)) \
{ \
__asm__ volatile (".long 0xfffd0000\n" ".long %0\n"::"i,!r" (string)); \
} \
else \
{ \
__asm__ volatile (".short 0xfffe\n" ".short %0\n"::"r" (string)); \
}; \
__asm__ volatile (".short 0xffff\t#" "puts" "\n\t" \
".short %1\n":"=&r" (__v0):"i" (1)); \
__asm__ volatile (".set\tpop\n"); \
(int) __v0; \
})
Surely that would work.
Andrew.
