GCC vs Sun CC on SPARC

[James Morrison]

Eric Botcazou <ebotcazou@libertysurf.fr> writes:

> Summary:
> - the Sun compiler produces very large (stripped) binaries with -fast, whose 
> size is only matched by GCC with -funroll-all-loops (this latter option 
> doesn't help wrt to -O2 and -O3, except for GCC 3.3.2).
> - in 32-bit mode, GCC 2.95.3 code runs slower than Sun CC code (time delta: 
> 13.5%), while GCC 3.3.2 code is on par with GCC 2.95.3 code (but only with  
> -funroll-all-loops).  GCC 3.4pre code is always faster than the 3 others 
> (time delta: -2.5% against Sun CC).
> - in 64-bit mode, GCC 3.3.2 code runs slower than Sun CC code (time delta: 
> 20%) and GCC 3.4pre code runs slower than Sun CC code too, although by 
> roughly half the previous margin (time delta: 11%).
> 
> 
> The results for GCC 3.4pre are pretty encouraging (amazing ?), especially in 
> 32-bit mode, but even in 64-bit mode given the larger initial gap.  I'm 
> going to try to figure out where the difference comes from.  Any ideas?
> 
> -- 
> Eric Botcazou

 Were any of these tests using -mtune=ultrasparc[123] ?

Jim