[tree-ssa] Speed up constant propagation [patch]

[Diego Novillo]

On Tue, 2003-06-17 at 05:08, Richard Guenther wrote:

> The worst case test went down from 38 minutes to 4:15 (mainline is 3:23)!
> Nice work! Time report follows (-fno-exceptions -O2 -march=athlon
> -funroll-loops).
> 
Cool.  Glad to hear that.

>  tree alias analysis   :  22.45 ( 9%) usr   0.11 ( 3%) sys  22.44 ( 9%) wall
>  tree PHI insertion    :  83.14 (33%) usr   0.39 ( 9%) sys  83.50 (33%) wall
>  tree SSA rewrite      :   8.73 ( 3%) usr   0.07 ( 2%) sys   8.93 ( 3%) wall
>  tree SSA other        :   2.77 ( 1%) usr   0.08 ( 2%) sys   2.87 ( 1%) wall
>  tree SSA to normal    :  12.39 ( 5%) usr   0.12 ( 3%) sys  12.44 ( 5%) wall
>  tree CCP              :  17.76 ( 7%) usr   0.13 ( 3%) sys  17.88 ( 7%) wall
>  tree COPYPROP         :   1.07 ( 0%) usr   0.00 ( 0%) sys   1.05 ( 0%) wall
>  tree DCE              :   4.41 ( 2%) usr   0.11 ( 3%) sys   4.57 ( 2%) wall
>
Which one is it?  PHI insertion times are pretty bad.  If we manage to
get that one below 10 secs, we will be beating mainline :)  (not that I
think this will be necessarily trivial, but if the test has heavy
aliasing, we may consider introducing zero-versions, a-la ORC, or see if
PTA helps).


Diego.