Large Fortran program succesfully LTO'd.

[Jan Hubicka]

> Honza,
> 
> At the Cauldron meeting last week I mentioned that I wasn't able to compile
> our "small" weather forecasting program with LTO.
> 
> In the mean time I have read some bug reports with "multiple prevailing ..."
> errors, which made me try linking with the 'gold' linker - that worked.
> 
> So the only things building the software that I changed were adding -flto
> and -fuse-ld=gold.
> 
> Some statistics of the source code:
> 
> 3902 files totaling 1081944 lines.
> 
> The result works flawlessly.
> 
> Over the weekend I will study the LTO diagnostics to see what decisions were
> made with respect to inlining and other optimizations.

Great to hear, thanks!   I wonder if it would be possible to have -flto-report -fmem-report -Q
output of the link.  I am just trying to get more agressive type merging to work but it is
C++ only (because i can make use of the ODR rule here) and I wonder how many types you
get in other languages (hope is that C++ is the type heaviest of them all)

I would be interested if performance looks good, too!
Honza
> 
> Thanks !
> 
> -- 
> Toon Moene - e-mail: toon@moene.org - phone: +31 346 214290
> Saturnushof 14, 3738 XG  Maartensdijk, The Netherlands
> At home: http://moene.org/~toon/; weather: http://moene.org/~hirlam/
> Progress of GNU Fortran: http://gcc.gnu.org/wiki/GFortran#news