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Re: Tremendous increase in compile times for 3.4.1 with -mcpu=G5
- From: Bradley Lucier <lucier at math dot purdue dot edu>
- To: Dale Johannesen <dalej at apple dot com>
- Cc: Bradley Lucier <lucier at math dot purdue dot edu>, David Edelsohn <dje at watson dot ibm dot com>, Matt Austern <austern at apple dot com>, gcc at gcc dot gnu dot org
- Date: Tue, 10 Aug 2004 23:00:09 -0500
- Subject: Re: Tremendous increase in compile times for 3.4.1 with -mcpu=G5
On Tuesday, August 10, 2004, at 10:52 PM, Dale Johannesen wrote:
I suppose, but it's not obvious why that would cause local_alloc to do
that
much more work. Could we be tickling a bad algorithm in local-alloc?
There's more discussion in the PR,
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=16975
It appears that the main problem may be a slowdown in sbitmaps (used in
invalid_mode_change_p) caused by using HOST_WIDE_INTs. See also
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=13987
Brad