On Tue, 7 Nov 2000, Anders Magnusson wrote:

> I beg to differ. VAX is probably the architecture where gcc is best
> compared to the native compilers, and the vcc that follows Ultrix at
> least is more than bad; both in code generation and buggyness.
> 
> To illustrate this I took some time and made a simple benchmark: On a
> VAX8800 running Ultrix 4.5 I compiled the AT&T dc with those three
> compilers, and made it calculate something that takes time. dc do not
> use any library routines for its internal work so the differences do
> fairly well mirror the compiler efficiency:
> 
> Running the command:
> % echo "2 9999 ^ 3 6308 ^ / p" | /usr/bin/time ./dc
> 
> gave the following results:
> 
> cc:
>        44.7 real        44.4 user         0.0 sys
> 
> vcc:
>        51.0 real        50.8 user         0.0 sys  
> 
> gcc:
>        31.3 real        31.1 user         0.0 sys  
> 
> 
> This shows that there is a huge difference between the efficiency of
> those compilers. 
> All tests was compiled with -O on the compilers.

Okay, well that seems at least somewhat enlightening though obviously not
definitive.  So does anyone actually know of any real performance issues
with the code gcc generates.  I think we all know that there's a lot of
overhead with running gcc.  It sounded like there were some known issues
with it's code generation.

Are there any?

-brian.
--- Brian Chase | bdc@world.std.com | http://world.std.com/~bdc/ -----
This counter is [6,177,399,753] times as pointless as a real one.  -- K.