Re: [MiNT] PGO

[Vincent Rivière <vincent.riviere@freesbee.fr>]

Pawe? Góralski wrote:
> BTW, anyone has tried PGO feature (profile guided optimisation that came 
> with gcc 4) on Atari apps? Some people say that it can give very good 
> results (code execution speed increases).

I didn't know that feature.

I found that explanation:
http://mituzas.lt/2009/07/27/profile-guided-optimization-with-gcc/

When I compile with -fprofile-generate it fails because there are a lot of 
unresolved exterals like ___gcov_one_value_profiler and so on.
If I look at libgconv.a it is basically empty.
The reason may be that inhibit_libc is defined to false when configuring gcc.
The reason for that is that I didn't use --with-sysroot or --with-headers 
while configuring gcc to tell it where the MiNTLib includes are.
There is a nice explanation on Patrice Mandin's page (step 8):
http://pagesperso-orange.fr/patrice.mandin/en/howto-cross333.html

So the PGO feature is disabled in my GCC binaries, but it may work by 
rebuilding GCC the right way !

--
Vincent Rrivière