[Speex-dev] Problem with Blackfin assembly optimizations -- bug in fixed_bfin.h / resampler saturation???

Jean-Marc Valin jean-marc.valin at usherbrooke.ca
Tue Feb 12 13:50:20 PST 2008 

OK, a few things got accidentally broken. I've partially fixed it in
svn/git (the limitation is that you can't link with both libspeex and
libspeexdsp if configured as fixed-point debug).

Can you compile/test now?

	Jean-Marc

Frank Lorenz a écrit :
> Hi,
> 
> when I compile with FIXED_DEBUG enabled, I get an error -- both when make tries to build testenc.o and when I try to link my app against the speex lib:
> 
> 
> lorenz at panelmaker:~/Blackfin/tests/speex_loopthrough$ make
> bfin-uclinux-gcc -c -g -I/home/lorenz/include -o main.o main.c
> bfin-uclinux-gcc -gl -elf2flt -L/home/lorenz/lib -o speex_through main.o -lspeex_debug -lspeexdsp -lm
> /home/lorenz/lib/libspeex_debug.a(bits.o): In function `speex_bits_set_bit_buffer':
> /home/lorenz/Blackfin/speex-1.2beta3/libspeex/bits.c:72: multiple definition of `_spx_mips'
> /home/lorenz/lib/libspeex_debug.a(speex.o):/home/lorenz/Blackfin/speex-1.2beta3/libspeex/speex.c:52: first defined here
> /home/lorenz/lib/libspeex_debug.a(modes.o): In function `speex_mode_query':
> /home/lorenz/Blackfin/speex-1.2beta3/libspeex/modes.c:359: multiple definition of `_spx_mips'
> /home/lorenz/lib/libspeex_debug.a(speex.o):/home/lorenz/Blackfin/speex-1.2beta3/libspeex/speex.c:52: first defined here
> /home/lorenz/lib/libspeex_debug.a(modes_wb.o): In function `speex_lib_get_mode':
> /home/lorenz/Blackfin/speex-1.2beta3/libspeex/modes_wb.c:293: multiple definition of `_spx_mips'
> /home/lorenz/lib/libspeex_debug.a(speex.o):/home/lorenz/Blackfin/speex-1.2beta3/libspeex/speex.c:52: first defined here
> /home/lorenz/lib/libspeex_debug.a(nb_celp.o): In function `_ADD32':
> /home/lorenz/Blackfin/speex-1.2beta3/libspeex/fixed_debug.h:207: multiple definition of `_spx_mips'
> /home/lorenz/lib/libspeex_debug.a(speex.o):/home/lorenz/Blackfin/speex-1.2beta3/libspeex/speex.c:52: first defined here
> /home/lorenz/lib/libspeex_debug.a(quant_lsp.o): In function `compute_quant_weights':
> /home/lorenz/Blackfin/speex-1.2beta3/libspeex/quant_lsp.c:72: multiple definition of `_spx_mips'
> /home/lorenz/lib/libspeex_debug.a(speex.o):/home/lorenz/Blackfin/speex-1.2beta3/libspeex/speex.c:52: first defined here
> /home/lorenz/lib/libspeex_debug.a(sb_celp.o): In function `_DIV32':
> /home/lorenz/Blackfin/speex-1.2beta3/libspeex/fixed_debug.h:466: multiple definition of `_spx_mips'
> /home/lorenz/lib/libspeex_debug.a(speex.o):/home/lorenz/Blackfin/speex-1.2beta3/libspeex/speex.c:52: first defined here
> /home/lorenz/lib/libspeex_debug.a(speex_callbacks.o): In function `speex_default_user_handler':
> /home/lorenz/Blackfin/speex-1.2beta3/libspeex/speex_callbacks.c:140: multiple definition of `_spx_mips'
> /home/lorenz/lib/libspeex_debug.a(speex.o):/home/lorenz/Blackfin/speex-1.2beta3/libspeex/speex.c:52: first defined here
> /home/lorenz/lib/libspeex_debug.a(window.o):(.bss+0x0): multiple definition of `_spx_mips'
> /home/lorenz/lib/libspeex_debug.a(speex.o):/home/lorenz/Blackfin/speex-1.2beta3/libspeex/speex.c:52: first defined here
> /home/lorenz/lib/libspeex_debug.a(cb_search.o): In function `compute_weighted_codebook':
> /home/lorenz/Blackfin/speex-1.2beta3/libspeex/cb_search_bfin.h:38: multiple definition of `_spx_mips'
> /home/lorenz/lib/libspeex_debug.a(speex.o):/home/lorenz/Blackfin/speex-1.2beta3/libspeex/speex.c:52: first defined here
> /home/lorenz/lib/libspeex_debug.a(filters.o): In function `normalize16':
> /home/lorenz/Blackfin/speex-1.2beta3/libspeex/filters_bfin.h:37: multiple definition of `_spx_mips'
> /home/lorenz/lib/libspeex_debug.a(speex.o):/home/lorenz/Blackfin/speex-1.2beta3/libspeex/speex.c:52: first defined here
> /home/lorenz/lib/libspeex_debug.a(lsp.o): In function `lsp_enforce_margin':
> /home/lorenz/Blackfin/speex-1.2beta3/libspeex/lsp.c:594: multiple definition of `_spx_mips'
> /home/lorenz/lib/libspeex_debug.a(speex.o):/home/lorenz/Blackfin/speex-1.2beta3/libspeex/speex.c:52: first defined here
> /home/lorenz/lib/libspeex_debug.a(ltp.o): In function `inner_prod':
> /home/lorenz/Blackfin/speex-1.2beta3/libspeex/ltp_bfin.h:38: multiple definition of `_spx_mips'
> /home/lorenz/lib/libspeex_debug.a(speex.o):/home/lorenz/Blackfin/speex-1.2beta3/libspeex/speex.c:52: first defined here
> /home/lorenz/lib/libspeex_debug.a(vbr.o): In function `vbr_destroy':
> /home/lorenz/Blackfin/speex-1.2beta3/libspeex/vbr.c:272: multiple definition of `_spx_mips'
> /home/lorenz/lib/libspeex_debug.a(speex.o):/home/lorenz/Blackfin/speex-1.2beta3/libspeex/speex.c:52: first defined here
> /home/lorenz/lib/libspeex_debug.a(vq.o): In function `vq_nbest':
> /home/lorenz/Blackfin/speex-1.2beta3/libspeex/vq_bfin.h:38: multiple definition of `_spx_mips'
> /home/lorenz/lib/libspeex_debug.a(speex.o):/home/lorenz/Blackfin/speex-1.2beta3/libspeex/speex.c:52: first defined here
> /home/lorenz/lib/libspeex_debug.a(lpc.o): In function `_spx_lpc':
> /home/lorenz/Blackfin/speex-1.2beta3/libspeex/lpc.c:78: multiple definition of `_spx_mips'
> /home/lorenz/lib/libspeex_debug.a(speex.o):/home/lorenz/Blackfin/speex-1.2beta3/libspeex/speex.c:52: first defined here
> collect2: ld gab 1 als Ende-Status zurÃŒck
> make: *** [speex_through] Fehler 1
> 
> 
> again: any ideas how to proceed?
> 
> best regards,
> Frank
> 
> 
> 
> -----Ursprüngliche Nachricht-----
> Von: "Jean-Marc Valin" <jean-marc.valin at usherbrooke.ca>
> Gesendet: 08.02.08 21:50:56
> An: Frank Lorenz <Frank_wtal at web.de>
> CC: speex-dev at xiph.org
> Betreff: Re: [Speex-dev] Problem with Blackfin assembly optimizations -- bug in fixed_bfin.h / resampler saturation???
> 
> 
> Frank Lorenz a écrit :
>> Yes, this is another point: I wrote that the resampler breaks, but
>> this is not the case. Instead, the speex encoder corrupts its input
>> buffer when the "DIV32_16 bug" described above happens. Do you have
>> any idea how to proceed?
> 
> Can you try enabling --enable-fixed-point-debug (FIXED_DEBUG) and see if
> any error gets printed. I suspect there might be a place where the
> assumptions of DIV32_16 are violated, i.e. either the right hand side
> doesn't fit in 16 bits or the result doesn't fit in 16 bits. Can you check?
> 
> 	Jean-Marc
> 
>> best regards, Frank
>>
>>
>> -----Ursprüngliche Nachricht----- Von: "Jean-Marc Valin"
>> <jean-marc.valin at usherbrooke.ca> Gesendet: 06.02.08 11:07:46 An:
>> Frank Lorenz <Frank_wtal at web.de> CC: speex-dev at xiph.org Betreff: Re:
>> [Speex-dev] Problem with Blackfin assembly optimizations -- bug in
>> fixed_bfin.h / resampler saturation???
>>
>>
>> Frank Lorenz a écrit :
>>> I just started to examine the DIV32_16 function (Blackfin ASM 
>>> version), and wondered why the return value of the function inside 
>>> 'fixed_bfin.h' is of type 'spx_word16_t', but the local variable 
>>> 'res' which is returned by this function is of type 'spx_word32_t'.
>>>  Is this a trick of optimization or a bug? (Same question for 
>>> PDIV32_16 and MAX16, too!)
>> Neither (AFAIK). The idea is that sometimes gcc does 
>> silly/counter-intuitive things when I specify a 16-bit variable as a 
>> constraint. That way, I force the top 16 bits to be zero.
>>
>> Jean-Marc
>>
>>> best regards, Frank
>>>
>>>
>>> -----Ursprüngliche Nachricht----- Von: "Jean-Marc Valin" 
>>> <jean-marc.valin at usherbrooke.ca> Gesendet: 02.02.08 06:26:08 An: 
>>> speex-dev <speex-dev at xiph.org> Betreff: Re: FW: Re: [Speex-dev] 
>>> Problem with Blackfin assembly optimizations -- bug in fixed_bfin.h
>>> / resampler saturation???
>>>
>>>
>>> Frank Lorenz a écrit :
>>>> And yes, the same "overflow" happens even when I disable Blackfin
>>>>  ASM optimizations.
>>> Indeed, that shouldn't happen. Just to make sure I understand, so
>>> far there's two problems: 1) DIV32_16() in Blackfin assembly causes
>>>  problems 2) The resampler overflows
>>>
>>> When you fix/workaround those two, is the encoder/decoder working 
>>> correctly or are there other issues?
>>>
>>> About the DIV32_16() issue, could you try and replace it with a 
>>> function that compares the Blackfin-asm result with the real
>>> division and dumps the args and output when they don't match. I'd
>>> like to understand for what inputs that functions fails. That would
>>> help in fixing the problem.
>>>
>>> Thanks,
>>>
>>> Jean-Marc
>>>
>>>> best regards, Frank
>>>>
>>>> -----Ursprüngliche Nachricht----- Von: "Jean-Marc Valin" 
>>>> <jean-marc.valin at usherbrooke.ca> Gesendet: 01.02.08 12:11:39 An:
>>>>  Frank Lorenz <Frank_wtal at web.de> CC: speex-dev at xiph.org Betreff:
>>>>  Re: FW: Re: [Speex-dev] Problem with Blackfin assembly 
>>>> optimizations -- bug in fixed_bfin.h / resampler saturation???
>>>>
>>>>
>>>> Frank Lorenz a écrit :
>>>>> didn't get a reply to my last post (see below) -- do you have
>>>>> no idea what happens here?
>>>> Sorry, been quite busy lately. Still have a backlog of things to
>>>>  respond to (sorry to others as well), some of it quite old.
>>>>
>>>>> After some more tests, I disabled the DIV32_16 Blackfin 
>>>>> optimizations and now get good quality on the Blackfin.
>>>> OK, I'll need to investigate that one. It's mostly taken from the
>>>>  ADI manual, so I don't see what could have happened.
>>>>
>>>>> But when I have overdrive on the input, things become very bad
>>>> Does that happen without any assembly. Some amount of badness is
>>>>  expected from the fixed-point because of saturation issues. It 
>>>> shouldn't overflow though (can you check?)
>>>>
>>>>> -- I'm not sure if this is really a filter stability issue like
>>>>> I wrote some weeks ago.
>>>> I don't think it has to do with filters.
>>>>
>>>>> I use the speex resampler to downsample from 48 to 16 kHz. When
>>>>> I look to the downsampled signal before passing it to the
>>>>> encoder, there seems to be a bug in saturation. On overdrive,
>>>>> instead of holding a too big signal value at maximum (e.g.
>>>>> 32767) for some samples, the sample values I get from the
>>>>> resampler are [-32768,32767,-32768,...], i.e. the output of the
>>>>> resampler alters between the biggest possible negative value
>>>>> and the biggest possible positive value.
>>>> This is definitely bad. Can you send me an example file. Also,
>>>> can you reproduce that problem without the Blackfin assembly?
>>>>
>>>>> Does the resampler use the hardware saturation available on 
>>>>> Blackfin, or does it saturate by software? Can you point me to 
>>>>> the place I have to look at inside the resampler function for 
>>>>> saturation?
>>>> Saturation is entirely done in software. The resampler does the 
>>>> conversion using the WORD2INT macro.
>>>>
>>>> Jean-Marc
>>>>
>>>>
>>>>
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> 
> 
> 
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