Bug#840458: linbox: FTBFS on i386: illegal instruction in test-{cra, charpoly}

[Tobias Hansen]

Hi Doug,

I think I figured out at least the test failures with "Illegal
instruction" on i386. The problem is that givaro is built using cpu
extensions that are not allowed.

Jerome figured out in [1] that the problem happens when givaro code is
called. And sure enough:

objdump -S /usr/lib/i386-linux-gnu/libgivaro.so.9.0.0 | grep
'\b\(ymm\|zmm\|vfm\)'
   15411:	c4 e3 79 6b 8b a4 29 	vfmaddsd %xmm2,-0x1d65c(%ebx),%xmm0,%xmm1
   154d1:	c4 e3 69 6b 8b ac 29 	vfmaddsd %xmm0,-0x1d654(%ebx),%xmm2,%xmm1

And in the i386 build logs for givaro there are these flags:
-mmmx -mpopcnt -msse -msse2 -msse3 -msse4.1 -msse4.2 -msse4a -mavx
-mfma4 -mfpmath=sse

Do you have time in the next days to disable these flags? Otherwise I
can do it. (I'm not sure if some of these flags (mmx, sse ?) are allowed
on i386 and didn't find that info. Ximin, do you know this?)

Best,
Tobias

[1] https://github.com/linbox-team/linbox/issues/44

On Tue, 11 Oct 2016 14:02:24 -0400 "Aaron M. Ucko" <amu at alum.mit.edu> wrote:
> Source: linbox
> Version: 1.4.2-1
> Severity: serious
> Justification: fails to build from source (but built successfully in the past)
> 
> The i386 build of linbox failed:
> 
>   ../build-aux/test-driver: line 107: 16085 Illegal instruction     "$@" > $log_file 2>&1
>   FAIL: test-cra
>   [...]
>   ../build-aux/test-driver: line 107: 16135 Illegal instruction     "$@" > $log_file 2>&1
>   FAIL: test-charpoly
> 
> Could you please take a look?
> 
> Thanks!
> 
> -- 
> Aaron M. Ucko, KB1CJC (amu at alum.mit.edu, ucko at debian.org)
> http://www.mit.edu/~amu/ | http://stuff.mit.edu/cgi/finger/?amu@monk.mit.edu
> 
>