Re: [arm-gnu] How to make gas accept Thumb2 insns on armv6-m ?

[Daniel Jacobowitz <dan@xxxxxxxxxxxxxxxx>]

On Mon, Jun 08, 2009 at 04:49:48PM +0200, Christophe LYON wrote:
>
>> First of all, if you want to write Thumb-2, I believe you need
>> ".syntax unified" to get consistent behavior.  That will fix the
>> "dest must overlap one source register" error for armv6t2.
>>
>
> Sorry for the dumb follow-up: could you tell me where I can find some doc 
> on this unified syntax? I have grepped through your latest release doc 
> directory, and could only find references to it (eg in getting-started).

It's as documented in the ARM reference manuals.  There isn't a
separate GAS reference for it.

> In particular, just adding ".syntax unified" leads to other errors
> toto.s:3: Error: cannot honor width suffix -- `mul r3,r0,r3'
> toto.s:4: Error: cannot honor width suffix -- `mul ip,r2,r1'

I'm not entirely sure about this error in the first case, since that
ought to be valid as a 16-bit mul, shouldn't it?  The second case is
an unclear error message, but correct; that would have to be mul.w,
and as previously mentioned, armv6-m does not have mul.w.

-- 
Daniel Jacobowitz
CodeSourcery