[Speex-dev] Re: sigsegv in _mm_load_ups (linux/gcc 3.x)

Jean-Marc Valin Jean-Marc.Valin at USherbrooke.ca
Fri Jan 6 17:24:06 PST 2006

Tom, Thorvald,

Could one of you submit the details to the gcc bugzilla so it gets
fixed? BTW, is 4.0 affected?


Le vendredi 06 janvier 2006 à 17:13 -0800, Tom Harper a écrit :
> Thorvald,
> re:
> At 03:18 AM 1/6/2006, Thorvald Natvig wrote:
> >I just checked it in the debugger, and this was with gcc 3.4.4 (mingw)... 
> >And the addresses were not properly aligned :( From a bit of googling, 
> >this seems to be a thread problem, as the gcc just maintains 16-byte 
> >alignment of the stack -- if the start function of the thread had 
> >misaligned stack,  the misalignment will be kept throughout the execution.
> Thanks!  This is exactly the issue- that, and the fact that gcc seems to be
> issuing a movaps call that copies into unaligned memory right after loading
> the xmm register.  No matter how we put the code together it always issues
> the movaps (probably because it needs more than 8 registers)- I am sure this
> code  would work fine on a machine with 16 xmm registers.  For now we will
> just use the c code for the unaligned _10 call.  Probably this could be fixed
> also by hand coding this particular chunk of assembler.
> Tom 
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