Speex dev - Dec 2007 - Speex crashing on ARM with assembler optimization enabled.

Hi,

I'm trying to get speex working on an ARM board (ARM926EJ-Sid(wb) core,
ARM 5TE architecture) and getting segfaults if build with
"--enable-fixed-point
--enable-arm5e-asm" options. If I use just
"--enable-fixed-point", then
it runs fine, but once I add "--enable-arm5e-asm" it start crashing
(I use testenc to test it).

Further investigation showed, that it does not crash, if I enable arm asm
but disable both VAR_ARRAYS and USE_ALLOCA in config.h.

This tested with speex svn rev13928 and with 1.2beta3 (svn rev14298).
gcc version is 4.2.0

I guess it may be some alignment problem or so, like with MS compilers?
Did anyone had same problems? Any good ideas and directions where to
look and debug are welcome.


-- 
Regards,
Alexander Chemeris.

SIPez LLC.
SIP VoIP, IM and Presence Consulting
http://www.SIPez.com
tel: +1 (617) 273-4000

Did you test what happens if you only enable arm4 assembly? Also, if you
can do some investigation, it would be useful to check what bit of
assembly is causing the crash. Can you disable one at a time and check?

	Jean-Marc

Alexander Chemeris a ?crit :
> Hi,
> 
> I'm trying to get speex working on an ARM board (ARM926EJ-Sid(wb) core,
> ARM 5TE architecture) and getting segfaults if build with
"--enable-fixed-point
> --enable-arm5e-asm" options. If I use just
"--enable-fixed-point", then
> it runs fine, but once I add "--enable-arm5e-asm" it start
crashing
> (I use testenc to test it).
> 
> Further investigation showed, that it does not crash, if I enable arm asm
> but disable both VAR_ARRAYS and USE_ALLOCA in config.h.
> 
> This tested with speex svn rev13928 and with 1.2beta3 (svn rev14298).
> gcc version is 4.2.0
> 
> I guess it may be some alignment problem or so, like with MS compilers?
> Did anyone had same problems? Any good ideas and directions where to
> look and debug are welcome.
> 
>

On 12/13/07, Jean-Marc Valin <jean-marc.valin@usherbrooke.ca>
wrote:
> Did you test what happens if you only enable arm4 assembly?
Sure. I tested with "--enable-arm4-asm" and there was no difference.
> Also, if you can do some investigation, it would be useful to check what
bit
> of assembly is causing the crash. Can you disable one at a time and check?
ok. I'll try binary search, disabling optimizations.

Here is disasm of segfault point. Probably it may be helpful.

(gdb) bt
#0  0x40030334 in open_loop_nbest_pitch () from ./libspeex.so.1
#1  0x400313cc in pitch_search_3tap () from ./libspeex.so.1
#2  0x4002bec0 in nb_encode () from ./libspeex.so.1
#3  0x40036c84 in speex_encode_int () from ./libspeex.so.1
#4  0x00008d68 in main ()

(gdb) disassemble
Dump of assembler code for function open_loop_nbest_pitch:
... skipped...
0x40030300 <open_loop_nbest_pitch+620>: add     r0, r3, r8
0x40030304 <open_loop_nbest_pitch+624>: ldrsh   r3, [r0]
0x40030308 <open_loop_nbest_pitch+628>: mov     r3, r3, lsl #1
0x4003030c <open_loop_nbest_pitch+632>: strh    r3, [r0], #2
0x40030310 <open_loop_nbest_pitch+636>: add     r6, r6, #1      ; 0x1
0x40030314 <open_loop_nbest_pitch+640>: cmp     r6, r7
0x40030318 <open_loop_nbest_pitch+644>: bne     0x40030304
<open_loop_nbest_pitch+624>
0x4003031c <open_loop_nbest_pitch+648>: ldr     r3, [r11, #-92]
0x40030320 <open_loop_nbest_pitch+652>: cmp     r9, r3
0x40030324 <open_loop_nbest_pitch+656>: blt     0x40030474
<open_loop_nbest_pitch+992>
0x40030328 <open_loop_nbest_pitch+660>: mov     r6, r3
0x4003032c <open_loop_nbest_pitch+664>: mov     r7, #0  ; 0x0
0x40030330 <open_loop_nbest_pitch+668>: ldr     lr, [r11, #-84]
0x40030334 <open_loop_nbest_pitch+672>: ldrh    r3, [r7, lr]
0x40030338 <open_loop_nbest_pitch+676>: smulbb  r3, r3, r3
0x4003033c <open_loop_nbest_pitch+680>: mov     r3, r3, lsl #16
0x40030340 <open_loop_nbest_pitch+684>: mov     r12, r3, lsr #16
0x40030344 <open_loop_nbest_pitch+688>: ldr     r3, [r4, r10, lsl #2]
0x40030348 <open_loop_nbest_pitch+692>: smulbb  r1, r12, r3
0x4003034c <open_loop_nbest_pitch+696>: ldr     r2, [r11, #-80]
0x40030350 <open_loop_nbest_pitch+700>: ldrh    r0, [r7, r2]
0x40030354 <open_loop_nbest_pitch+704>: ldr     r2, [r5, r10, lsl #2]
0x40030358 <open_loop_nbest_pitch+708>: add     r3, r0, #1      ; 0x1
0x4003035c <open_loop_nbest_pitch+712>: smulbb  lr, r2, r3
0x40030360 <open_loop_nbest_pitch+716>: cmp     r1, lr
0x40030364 <open_loop_nbest_pitch+720>: ble     0x40030464
<open_loop_nbest_pitch+976>

(gdb) info registers
r0             0x4554   17748
r1             0x0      0
r2             0x38a1   14497
r3             0x4555   17749
r4             0xbec831ec       3200791020
r5             0xbec831f4       3200791028
r6             0xae84beb2       2927935154
r7             0xc7c    3196
r8             0x38a1   14497
r9             0x50     80
r10            0x0      0
r11            0xbec83464       3200791652
r12            0x0      0
sp             0xbec831e4       0xbec831e4
lr             0xbec83384       3200791428
pc             0x40030334       0x40030334 <open_loop_nbest_pitch+672>
fps            0x0      0
cpsr           0x10     16


I'm not very familiar with gdb, so excuse me if I'm doing something
wrong
with it. gdb is not very friendly to newcommers. :)


-- 
Regards,
Alexander Chemeris.

SIPez LLC.
SIP VoIP, IM and Presence Consulting
http://www.SIPez.com
tel: +1 (617) 273-4000