[Bug tree-optimization/19794] [meta-bug] Jump threading related bugs

["law at redhat dot com" <gcc-bugzilla@gcc.gnu.org>]

------- Additional Comments From law at redhat dot com  2005-04-02 01:31 -------
Some notes on recent poking and prodding.

The big perl speedup is consistent on my P4 -- but perl shows no significant
change on my AMD box.  Perl spends ~50% of its time in one routine (regexec)
and, surprise, that's the routine where profiling shows the great improvements.

Unfortunately, the profiling data hasn't pinpointed _why_ that routine is
running so much faster.  If one is to believe the oprofile data, the
huge reduction in cycles actually occurs in the function's header block.
But it's not substantially different between the version compiled with
and without the threading updates.  And it does not appear that threading has
turned any of the recursive calls into simple loops.  Looking at the profile
results from different P4 counters hasn't provided any additional insight
yet.  Sigh.

Anyway, I'll continue poking at Perl -- I'd really like to understand the 
huge improvements before installing the patch. 

-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=19794