llvm dev - Jan 2014 - [LLVMdev] making emitInlineAsm protected

On 01/29/2014 02:32 PM, Eric Christopher wrote:
> On Wed, Jan 29, 2014 at 2:27 PM, reed kotler <rkotler at mips.com>
wrote:
>> On 01/29/2014 02:18 PM, Rafael Espíndola wrote:
>>>>
>>>> I'd like to just check my code in and then you can look at
it in it's
>>>> totality and see if you have
>>>> a better solution .
>>>
>>> No!
>>>
>>> If it is the compiler creating instructions, it is not inline
>>> assembly. If you need to print mips16 and mips32 and they are two
>>> independent instruction sets, my guess is that you need to figure
out
>>> how to swap between two AsmPrinters.
>>>
>>> Cheers,
>>> Rafael
>>
>> We do switch them already.
>>
>> We create different functions for the stubs and assign them the mips32
>> attribute.
>>
>> Then they get assembled.
>>
>> The need for these particular stubs cannot be recognized until isel
>> lowering.
>>
>> Why do I need to make a complex mechanism here when all I need to do is
emit
>> some
>> some inline assembly code at the end of asm printer?
>>
>> What purpose will this serve?
>>
>
> Because we're not an assembly emitting compiler. We're an object
file
> emitting compiler and it's breaking abstractions. The correct way to
> do the work here is to emit the functions and lower them
> appropriately.
>
> -eric
>
So explain to me how this mechanism would work.

As I'm processing a single mips16 function, I realize that I need to 
create one or more mips32 helper functions.

I'm in a function pass. So I'm not supposed to be creating new 
functions, as far as I understand.


Also, I can't know which mips32 stub functions to create until I have 
processed all functions because otherwise I might create duplicates.


So how would you do this within the existing LLVM pass structure?

Reed

> So explain to me how this mechanism would work.
>
> As I'm processing a single mips16 function, I realize that I need to
create
> one or more mips32 helper functions.
>
> I'm in a function pass. So I'm not supposed to be creating new
functions, as
> far as I understand.
>
>
> Also, I can't know which mips32 stub functions to create until I have
> processed all functions because otherwise I might create duplicates.
>
>
> So how would you do this within the existing LLVM pass structure?
A module pass that iterates oven the functions should do it.

Cheers,
Rafael

On 01/29/2014 03:39 PM, Rafael Espíndola wrote:
>> So explain to me how this mechanism would work.
>>
>> As I'm processing a single mips16 function, I realize that I need
to create
>> one or more mips32 helper functions.
>>
>> I'm in a function pass. So I'm not supposed to be creating new
functions, as
>> far as I understand.
>>
>>
>> Also, I can't know which mips32 stub functions to create until I
have
>> processed all functions because otherwise I might create duplicates.
>>
>>
>> So how would you do this within the existing LLVM pass structure?
> A module pass that iterates oven the functions should do it.
>
> Cheers,
> Rafael
How would this pass get added to the chain?

It has to create more functions and then those in turn need to be compiled.

Reed