Re: about named address space

[Rony Paul <ronypaul77@gmail.com>]

On Wed, May 4, 2011 at 4:35 PM, Ian Lance Taylor <iant@google.com> wrote:
> Rony Paul <ronypaul77@gmail.com> writes:
>
>> Thank you for your reply. I am new in this development. so I am askig
>> you  very basic question. I dont have enough knowledge on "backend",
>> what did you man with this term?
>>
>> my task is to use one memory space as big endian, other as little
>> endian, and to use  copying of pointer from 1 memory space to another.
>> Just tell me what should be my beggining step? which files I should modify?
>
> Please reply to the mailing list, not just to me.  Also, please don't
> top-post.  Thanks.
>
> Re: backend: See http://en.wikipedia.org/wiki/Compilers .  In gcc the
> backend is the CPU-specific code in config/CPU.
>
> You haven't said anything about your target.  Is your memory different
> at the hardware level?  If not, named address spaces are probably not
> the right approach.
>
> Ian
>
>
>> Rony Paul <ronypaul77@gmail.com> writes:
>>
>>> I want to use named address space support to allow mixed endian
>>> applications. Specifying the endianness of address spaces.
>>> Can you suggest me what should I do in this purpose? and which files I
>>> need to modify ?
>>
>> In general named address space is described here:
>>
>> http://gcc.gnu.org/onlinedocs/gccint/Named-Address-Spaces.html
>>
>> You didn't mention which backend you are using and you didn't mention
>> how you mean to handle pointers to an address space of different
>> endianness.  Named address spaces seem appropriate if some of your
>> memory is big-endian and some is little-endian.  I don't know whether
>> they are appropriate if you want to have both big-endian and
>> little-endian pointers to the same area of memory.
>>
>> Ian
>
Thank you for the reply.

Yes I have separate memory at the hardware level. And as far I learnt
that named address space is already implemented for SPU processor. SPU
port uses the __ea address space to refer to memory in the host
processor, rather than memory local to the SPU processor.
I am now just in the learning phase. SO , if I want to modify that
code (just to learn) and want to add one more address space keyword
like "__ea"............what should I do?

And if I could change it, then my final target is to add named address
support for different endianess for i386.


- Rony