On Tue, Aug 1, 2017 at 11:05 PM, H.J. Lu <[email protected]> wrote:
> On Tue, Aug 1, 2017 at 1:49 PM, Uros Bizjak <[email protected]> wrote:
>> On Tue, Aug 1, 2017 at 9:46 PM, H.J. Lu <[email protected]> wrote:
>>> Add some tests for implementing interrupt handlers with naked attribute.
>>>
>>> OK for trunk?
>>>
>>> H.J.
>>> ---
>>> * gcc.dg/guality/pr25967-1.c: New test.
>>> * gcc.dg/guality/pr25967-2.c: Likewise.
>>> * gcc.dg/torture/pr25967-1.c: Likewise.
>>> * gcc.dg/torture/pr25967-2.c: Likewise.
>>
>> OK with a small change below.
>>
>
>>> +void
>>> +fn (void)
>>> +{
>>> + struct interrupt_frame *frame;
>>> + uword_t error;
>>> + asm ("lea " WORD_SIZE "(%%" STACK_POINTER "), %0" : "=r" (frame) : );
>>> + asm ("mov (%%" STACK_POINTER "), %0" : "=r" (error) : );
>>
>> The above two asm needs to be volatile. They are not "simple" asm, and
>> access stack pointer behind the compilers back. And please merge them
>> to one multi-line volatile asm statement.
>>
>
>
> This is what I am checking in.
OTOH, these asms can be avoided with something like:
--cut here--
typedef unsigned int uword_t __attribute__ ((mode (__word__)));
struct interrupt_frame
{
uword_t ip;
uword_t cs;
uword_t flags;
uword_t sp;
uword_t ss;
};
void
__attribute__((naked))
test (void)
{
register uword_t sp __asm__("sp");
long *error = (long *) sp;
struct interrupt_frame *frame
= (struct interrupt_frame *) (sp + sizeof (uword_t));
...
}
Uros.
