atomic_sub_and_test() asm constraints

atomic_sub_and_test() asm constraints

[Geert Uytterhoeven]

|   CC      mm/memcontrol.o
| {standard input}: Assembler messages:
| {standard input}:4076: Error: operands mismatch -- statement `subl
12(%fp),170(%a0)' ignored

Seems like we have bad asm constraints in

static inline int atomic_sub_and_test(int i, atomic_t *v)
{
        char c;
        __asm__ __volatile__("subl %2,%1; seq %0" : "=d" (c), "+m"
(*v): "g" (i));
        return c != 0;
}

Gr{oetje,eeting}s,

						Geert

--
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org

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when I'm talking to journalists I just say "programmer" or something like that.
							    -- Linus Torvalds

Re: atomic_sub_and_test() asm constraints

[Andreas Schwab]

Geert Uytterhoeven <geert@linux-m68k.org> writes:

> |   CC      mm/memcontrol.o
> | {standard input}: Assembler messages:
> | {standard input}:4076: Error: operands mismatch -- statement `subl
> 12(%fp),170(%a0)' ignored
>
> Seems like we have bad asm constraints in
>
> static inline int atomic_sub_and_test(int i, atomic_t *v)
> {
>         char c;
>         __asm__ __volatile__("subl %2,%1; seq %0" : "=d" (c), "+m"
> (*v): "g" (i));

Surely "g" is wrong, sub only accepts a data register as source operand
when the destination is in memory.

Andreas.

-- 
Andreas Schwab, schwab@linux-m68k.org
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