llvm dev - Feb 2010 - [LLVMdev] llc generated machine assembly code for NASM

Thanks for Anton's reply.
Does anybody have an idea of roughly how much effort is required to make
intel asm printer to be usable? If it is within weeks, probably I can give
it a try.
Thanks,

Bengu

On Thu, Jan 28, 2010 at 12:18 AM, Anton Korobeynikov <
anton at korobeynikov.info> wrote:
> Hello
>
> > system native assemlber and linker to generate executables. And it
> runs. I
> > ran into problems on Windows since the generated assembly code is not
> able
> > to be assembled by NASM.
> That's correct. Use AT&T asm printer and GNU as everywhere.
Everything
> else is too weak to be usable and thus one should consider intel asm
> printer to be of "listing quality".
>
> --
> With best regards, Anton Korobeynikov
> Faculty of Mathematics and Mechanics, Saint Petersburg State University
>
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Hello
> Does anybody have an idea of roughly how much effort is required to make
> intel asm printer to be usable? If it is within weeks, probably I can give
> it a try.
The required efforts equal to ones required to write new assembler.
"Too weak to be usable" means "it's not possible to represent
many
important constructs with masm/nasm/fasm".

-- 
With best regards, Anton Korobeynikov
Faculty of Mathematics and Mechanics, Saint Petersburg State University

On 01/28/2010 11:41 AM, Anton Korobeynikov wrote:
>
> The required efforts equal to ones required to write new assembler.
> "Too weak to be usable" means "it's not possible to
represent many
> important constructs with masm/nasm/fasm".
Wow.  It's perhaps too much of a distraction, but I'm curious about the 
details of this.  It's probably because it's first mission is to be a 
compiler back-end, but the common wisdom is that gas is bare-bones and 
masm is featureful.  Clearly that doesn't hold for what LLVM needs, and 
you imply it's true for the whole family of assemblers that use Intel 
syntax.  Very surprising to those of us (well, me anyway) with minimal 
time writing actual assembly.

Is any of this documented somewhere I can just go off and read, or is it 
just lore in the LLVM community?

Dustin

Could you give me some examples of such constructs that are not possible to
represent with MASM/NASM/FASM but are able to represent with gas?

Thanks,

Bengu

On Thu, Jan 28, 2010 at 11:41 AM, Anton Korobeynikov <
anton at korobeynikov.info> wrote:
> Hello
>
> > Does anybody have an idea of roughly how much effort is required to
make
> > intel asm printer to be usable? If it is within weeks, probably I can
> give
> > it a try.
> The required efforts equal to ones required to write new assembler.
> "Too weak to be usable" means "it's not possible to
represent many
> important constructs with masm/nasm/fasm".
>
> --
>  With best regards, Anton Korobeynikov
> Faculty of Mathematics and Mechanics, Saint Petersburg State University
>
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Hi, Anton,

For a simple example, I took the machine assembly code generated by llc and
with a little manual change on the assebmly code (the way how llc generates
.text segment is not accepted by MASM),  it is able to be assembled and
linked by MASM. And it runs. Haven't tried it on NASM yet.

I am sure that you've run into many problems when efforts were carried out
to implement the Intel ASM printer between version 1.6 and 1.7. I'd
appreciated it if you could point me to any document with regard to relavent
problems at that time. Probably I don't need a fully functional production
quality assembler for my purpose. If I could find out that the gap between
the current llc and what I need is not huge, I would like to enhance the llc
Intel ASM printer by myself.

Thanks,
Bengu

On Thu, Jan 28, 2010 at 11:41 AM, Anton Korobeynikov <
anton at korobeynikov.info> wrote:
> Hello
>
> > Does anybody have an idea of roughly how much effort is required to
make
> > intel asm printer to be usable? If it is within weeks, probably I can
> give
> > it a try.
> The required efforts equal to ones required to write new assembler.
> "Too weak to be usable" means "it's not possible to
represent many
> important constructs with masm/nasm/fasm".
>
> --
>  With best regards, Anton Korobeynikov
> Faculty of Mathematics and Mechanics, Saint Petersburg State University
>
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