Re: Huge compile time & run time performance regression 3.3 -> HEAD

[Richard Guenther <rguenth@tat.physik.uni-tuebingen.de>]

On Sun, 18 May 2003, Richard Guenther wrote:

> On Sun, 18 May 2003, Richard Guenther wrote:
>
> > Top of a profile of gcc3.4 is
> >
> > Flat profile:
> >
> > Each sample counts as 0.01 seconds.
> >   %   cumulative   self              self     total
> >  time   seconds   seconds    calls   s/call   s/call  name
> >   7.47     79.18    79.18      906     0.09     0.09  compute_store_table
> >   6.92    152.54    73.36 262785751     0.00     0.00  expr_equiv_p
> >   6.76    224.21    71.67   170098     0.00     0.00  fixup_var_refs_insns
> >   5.58    283.38    59.17    12865     0.00     0.00  loop_regs_scan
> >   4.39    329.97    46.59   364279     0.00     0.00  compute_transp
>
> Compared to a 3.3 profile:
>
> Flat profile:
>
> Each sample counts as 0.01 seconds.
>   %   cumulative   self              self     total
>  time   seconds   seconds    calls  ms/call  ms/call  name
>   8.08     45.30    45.30   272942     0.17     0.17  compute_transp
>   7.15     85.38    40.08 263012170     0.00     0.00
> splay_tree_splay_helper
>   5.62    116.92    31.54 165540544     0.00     0.00  true_dependence
>   4.72    143.36    26.44 203228718     0.00     0.00
> mems_in_disjoint_alias_sets_p
>   3.80    164.68    21.32   171556     0.12     0.12  clear_table
>   3.61    184.92    20.24     9131     2.22     2.69  loop_regs_update

Sorry for always talking with myself in the public, but doesnt this look
like store-motion being the culprit? Wasnt that re-enabled in 3.4 only
(despite -fverbose-asm listing -fgcse-sm for both 3.3 and 3.4)?

Richard.