[LLVMdev] ARM thumb-2 instruction used for non-thumb2 CPUs

[Jim Grosbach]

On Jun 22, 2011, at 2:08 PM, Renato Golin wrote:

> On 22 June 2011 19:18, Anton Korobeynikov <anton at korobeynikov.info> wrote:
>> Unfortunately, you have to live with this. Until recently binutils
>> were quite buggy wrt thumb2 code, so, most probably you will need new
>> binutils in any case.
> 
> Hi Anton,
> 
> It's not so simple. GPL3 can be quite a nuisance to change and even to
> use. This is why LLVM is becoming to popular for ARM... ;)
> 
> Jim, how much work would you reckon it'll take to have a working assembler?
> 

You mean to patch the old binutils to support this old instruction? Very easy, I'd expect (well, as easy as anything ever is in binutils).

To get -integrated-as working so that we don't need to go through the assembler at all should be mostly a matter of bug fixing, modulo inline assembly support. For non-trivial inline assembly, and to get a system assembler replacement based on the MC assembler, it'll be a bigger task. The ARM asm parser is currently in need of some tender loving care. That's coming soon, but it's a non-trivial task.

For -integrated-as, I would suggest giving it a try. I'm not completely sure how complete the support is for ELF, but I think it's in somewhat OK shape, at least. Worth trying. That would neatly avoid the problem if it works. If it doesn't, we should fix the bugs so it does. ;)

-Jim