On 10/16/21 5:27 AM, Andrew Pinski wrote:
On Fri, Oct 15, 2021 at 6:53 AM Andrew MacLeod via Gcc-patches
<gcc-patches@gcc.gnu.org> wrote:
I've been looking at the pathological time issue ranger has with the
testcase from, uuuuuh.. PR 97623 I think. I've lost the details, but
kept the file since it was showing unpleasant behaviour.
Most of the time is spent in callbacks from substitute_and_fold to
value_on_edge() dealing with PHI results and arguments. Turns out, its
virtually all wasted time dealing with SSA_NAMES with the
OCCURS_IN_ABNORMAL_PHI flag set..
This patch tells ranger not to consider any SSA_NAMEs which occur in
abnormal PHIs. This reduces the memory footprint of all the caches, and
also has a ripple effect with the new threader code which uses the GORI
exports and imports tables, making it faster as well as no ssa-name with
the abnormal flag set will be entered into the tables.
That alone was not quite enough, as all the sheer volume of call backs
still took time, so I added checks in the value_of_* class of routines
used by substitute_and_fold to indicate there is no constant value
available for any SSA_NAME with that flag set.
On my x86_64 box, before this change, that test case looked like:
tree VRP : 7.76 ( 4%) 0.23 ( 5%) 8.02
( 4%) 537k ( 0%)
tree VRP threader : 7.20 ( 4%) 0.08 ( 2%) 7.28 (
4%) 392k ( 0%)
tree Early VRP : 39.22 ( 22%) 0.07 ( 2%) 39.44 (
22%) 1142k ( 0%)
And with this patch , the results are:
tree VRP : 7.57 ( 6%) 0.26 ( 5%) 7.85
( 6%) 537k ( 0%)
tree VRP threader : 0.62 ( 0%) 0.02 ( 0%) 0.65
( 0%) 392k ( 0%)
tree Early VRP : 4.00 ( 3%) 0.01 ( 0%) 4.03
( 3%) 1142k ( 0%)
Which is a significant improvement, both for EVRP and the threader..
The patch adjusts the ranger folder, as well as the hybrid folder.
bootstrapped on x86_64-pc-linux-gnu with no regressions and no missed
cases that I have been able to find.
Did you test it with go enabled?
Because others and myself are now running into a bootstrap failure
most likely due to this patch.
The number of SSA_NAME_OCCURS_IN_ABNORMAL_PHI in go is increased due
to -fnon-call-exceptions being true there.
I would have sworn upside down I did, but looking at my build script,
somewhere along the way GO got turned off, so although I was building
ada, GO was not being included.. sorry.
I'll get this resolved this afternoon.
Andrew
