Re: [Discuss-gnuradio] how to debug the SSE assembler files (float_dotprod_sse.S)

[Martin Dvh]

Eric Blossom wrote:
> On Wed, Oct 10, 2007 at 11:02:52PM +0200, Martin Dvh wrote:
>> Hi All,
>>
>> I am writing some new optimized SSE assembler routines.
>>
>> I am trying to debug them with gdb but are having the following problems.
>>
>> For some reason gdb doesn't find the source right, or shows the wrong source.
>>
>> When I set a breakpoint on float_dotprod_sse it thinks it is in file 
>> ../../../../../gnuradio-core/src/lib/general/gr_remez.cc, line 864.
>> While in fact it is in file 
>> ../../../../../gnuradio-core/src/lib/filter/float_dotprod_sse.S
>>
>> I added -Wa,--gdwarf2 to CCASFLAGS to enable debugging assembler files.
>>
>> Also when I step in the assembler routine, it only shows me line line 864 of 
>> gr_remez.cc as it thinks this is the current sourcefile.
>> And when I say list float_dotprod_sse it also shows gr_remez.cc
>>
>> Since I created a segfault in the assembler routine I would really like to 
>> step through it.
>>
>> Any ideas what goes wrong here, and how to solve it?
>>
>> Greetings and thanks,
>> Martin Dudok van Heel
> 
> Try make installing the code first, otherwise you have to use libtool to
> run gdb to get it happy.  After installing, you can use gdb without
> magic.
I already found that out.
I did first install the code.
But still it takes the wrong sourcefile.

Any other ideas?

I am now trying without O2. (although I am not sure the SSE code likes this. 
The function calls with floating point parameters change. (with O2,
they are put right into the xmm0 register))


> FWIW, I think the way to run it via libtool is
> 
>   $ libtool --mode=execute gdb test_filter
Haven't tried this.
> 
> However, I much prefer to run gdb from within emacs.
> Thus, my preference for "make install" ;)
With make install, you shouldn't have to think about it.

Greetings,
Martin
> 
> Eric
> 
>