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Re: [Announcement] Creating lightweight IPO branch
On Tue, May 5, 2009 at 10:38 AM, Andi Kleen <andi@firstfloor.org> wrote:
> On Tue, May 05, 2009 at 10:25:13AM -0700, Xinliang David Li wrote:
>> Andi,
>>
>> On Tue, May 5, 2009 at 1:49 AM, Andi Kleen <andi@firstfloor.org> wrote:
>> > Xinliang David Li <davidxl@google.com> writes:
>> >>
>> >> If the idea is generally accepted, I will prepare a series of patches
>> >> and submit them to gcc trunk.
>> >
>> > I was reading your wiki page. Interesting idea.
>> >
>> > One aspect that wasn't clear to me on reading it was how different
>> > compiler arguments for different files are handled. How would the
>> > compiler compiling another source file know what special arguments
>> > (like -I -D or special -f options) it needs? Or in what directory it
>> > was compiled in for -I paths? Or do you assume that is always all the
>> > same?
>>
>> This is actually mentioned in the document. Please see the section
>> about the module info record format. In each module info, the
>> information about -I paths, -D/-Us are recorded. Those will be passed
>> to the preprocessor when each module is processed.
>
> I found it after the post :/. But it seems to be only a small subset of
> options. ?How about -m or -f flags?
Right -- general option handling is yet need to be done. For instance,
we may not want to inline a function from a module with
-fstrict-aliasing to another function from a module with
-fno-strict-aliasing. This is a universal CMO problem. One simple
way is to use option checksum to make sure imported module has the
same option as the importing module.
Thanks,
David
>
> -Andi
>
> --
> ak@linux.intel.com -- Speaking for myself only.
>