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Re: [PATCH] i386: Assembly Implementation cleanup

On Wed, Aug 12, 2015 at 1:38 PM, Florian Weimer <> wrote:
> On 08/12/2015 09:22 PM, H.J. Lu wrote:
>> On Wed, Aug 12, 2015 at 8:06 AM, H.J. Lu <> wrote:
>>> On Wed, Aug 12, 2015 at 8:01 AM, Florian Weimer <> wrote:
>>>> On 08/12/2015 02:44 PM, H.J. Lu wrote:
>>>>> Is there a way to truly inline syscall with 6 arguments, not by calling
>>>>> __libc_do_syscall?
>> With my GCC 5 patch:
>> This updated patch will generate optimized code when GCC 5
>> or above is used.  Any comments?
> I like it.  Perhaps you could quote a bit of disassembly in the commit
> message?


> I would suggest to define a new macro (say,
> __usues_many_argument_syscall or something shorter) which expands to
> "__attribute__ ((optimize ("omit-frame-pointer), noinline))â on i386 and
> apply it to the function in the C source file, instead of adding it to
> the makefiles (assuming that this works, I have not tried it).  This
> way, it would be more explicit what happens.  In the documentation of
> the new macro, quote a typical GCC error message if a many-argument
> system call is used without it.

This only applies to syscalls with 6 arguments.  It is easier
to add -fomit-frame-pointer to Makefile than a new macro since
it has to be added by hand for each system call with 6 arguments.


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