Simple Value Range Propagation

[Zdenek Dvorak]

Hello,

> On Sun, 8 Jun 2003, Josef Zlomek wrote:
> > It takes 2% of compile time and adds 0.5 % overall performance on
> > SPECint2000.
> 
> Say that 35 times, and you'll end up with a compiler that is twice as
> slow.
> 
> And, in fact, GCC 3.3 _is_ already about twice as slow as GCC 2.95 for
> my application (without overall improvement in code quality, though,
> unlike your patch).

say this at every new optimization (because with the current structure
of gcc you cannot get much cheaper, considering that just a pass over
insns takes 1% of time), and you will end up with gcc 2.95 :-)

Zdenek