llvm dev - Feb 2010 - [LLVMdev] how to build eglibc using llvm-gcc without unsupported -fno-toplevel-reorder

Hi, Rafael

Inlined asm markup inside functions and on the top level is used to split
asm prologue/epilogue parts in very fine-grained manner.
So, splitting source c won't give the same result.

Regards,
Sergey Y.

2010/2/22 Rafael Espindola <espindola at google.com>

I haven't looked at the code, but why can't you split the .c
files
> into multiple files instead of splitting the generated asm? Not
> running gawk on produced assembly should be a nice cleanup anyway.
>
> Cheers,
> --
> Rafael Ávila de Espíndola
>
-------------- next part --------------
An HTML attachment was scrubbed...
URL:
<http://lists.llvm.org/pipermail/llvm-dev/attachments/20100222/6a994a74/attachment.html>

Hi,

llvm doesn't support -fno-toplevel-reorder option which affects
glibc/eglibc for some targets.
http://www.llvm.org/bugs/show_bug.cgi?id=6364
>From conversations with gcc and eglibc maintainers, seems option is
highly expected and is not going to deprecate.
>> 2010/2/23 Ian Lance Taylor <iant at google.com>:
>> If option is going to deprecate in gcc in near future as well, than it
>> make sense to consider changes in glibc(eglibc).
>> So, there are no plans to deprecate option. Did I understand correctly?
> Correct.  There are no plans to deprecate the -fno-toplevel-reorder
> option.
Are there any reasons why option can't be supported by llvm?

Regards,
Sergey Yakoushkin

2010/2/22 Török Edwin <edwintorok at gmail.com>:
> On 2010-02-21 23:36, Sergey Yakoushkin wrote:
>> Hi, Rafael
>>
>> Inlined asm markup inside functions and on the top level is used to
>> split asm prologue/epilogue parts in very fine-grained manner.
>> So, splitting source c won't give the same result.
>
> You could have 2 files:
>  - 1 which contains the function, and a marker where prolog ends
> (beginning of file is implicit marker of where it begins)
>  - 1 which contains the function, and a marker where epilog begins
> (end of file is implicit marker of where it ends)
>
> Or just look at ./sysdeps/x86_64/elf/initfini.c, its a single asm()
> block containing all relevant markers, and no C code.
> I think thats better than all these hacks to get the asm you want out of
> C code.
>
> Best regards,
> --Edwin