Re: Finding out the optimizations used by Octave

[George]

On 1/23/10, Jaroslav Hajek <address@hidden> wrote:
> On Sat, Jan 23, 2010 at 4:51 AM, George <address@hidden> wrote:
>> Is there an Octave command to find which CPU optimizations are in use?
>
> I'm not sure if that's what you mean, but the CPU instruction set used
> is usually fixed at the time of compilation. Typically it's the FPU
> instructions by default on 32-bit machines, and SSE instructions on
> 64-bit machines. It also heavily depends on the compiler and flags
> used. Some compilers, like Intel C++, can use a runtime dispatch to
> different code paths optimized for different platforms (yes and it's
> Intel-centric). To find out the compiler and flags used, you can do
> (in Octave):
>
> octave:1> octave_config_info ("CXX")
> ans = g++
> octave:2> octave_config_info ("CXXFLAGS")
> ans = -O3 -march=native
>

I remember installing Octave on Windows, and it would ask me which
optimizations I wanted to use. I remember it crashing if I used SSE3.
I suppose the selection was just about the Atlas libraries? I think
so.

But right now I'm using Octave on Debian, and I installed Octave from
the Debian repository. I get this:

octave:1> octave_config_info ("CXXFLAGS")
ans = -O2 -g
octave:2> octave_config_info ("CXX")
ans = g++

The -g option generates a debug build, right? Why would Debian
distribute a debug build?