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.
I don't want to push it quite yet as I wanted feedback to make sure we
don't actually do anything I'm not aware of with SSA_NAMES which have
the ABNORMAL_PHI flag set. Most of the code i can find in VRP and
vr-values appears to punt, so I presume not even considering those names
is fine?
This also seems like something that might be worth back-porting,
especially the hybrid pass parts...
Andrew
>From 146744fcde6a67f759ffc4aa3e8340861e229829 Mon Sep 17 00:00:00 2001
From: Andrew MacLeod <amacl...@redhat.com>
Date: Thu, 7 Oct 2021 10:12:29 -0400
Subject: [PATCH] Ranger : Do not process abnormal ssa-names.
* gimple-range-fold.h (gimple_range_ssa_p): Don't process names
that occur in abnormal phis.
* gimple-range.cc (gimple_ranger::range_on_edge): Return false for
abnormal and EH edges.
* gimple-ssa-evrp.c (rvrp_folder::value_of_expr): Ditto.
(rvrp_folder::value_on_edge): Ditto.
(rvrp_folder::value_of_stmt): Ditto.
(hybrid_folder::value_of_expr): Ditto for ranger queries.
(hybrid_folder::value_on_edge): Ditto.
(hybrid_folder::value_of_stmt): Ditto.
* value-query.cc (gimple_range_global): Always return a range if
the type is supported.
---
gcc/gimple-range-fold.h | 1 +
gcc/gimple-range.cc | 4 ++++
gcc/gimple-ssa-evrp.c | 39 ++++++++++++++++++++++++++++++++-------
gcc/value-query.cc | 3 ++-
4 files changed, 39 insertions(+), 8 deletions(-)
diff --git a/gcc/gimple-range-fold.h b/gcc/gimple-range-fold.h
index bc0874b5f31..350e2c4e039 100644
--- a/gcc/gimple-range-fold.h
+++ b/gcc/gimple-range-fold.h
@@ -93,6 +93,7 @@ gimple_range_ssa_p (tree exp)
{
if (exp && TREE_CODE (exp) == SSA_NAME &&
!SSA_NAME_IS_VIRTUAL_OPERAND (exp) &&
+ !SSA_NAME_OCCURS_IN_ABNORMAL_PHI (exp) &&
irange::supports_type_p (TREE_TYPE (exp)))
return exp;
return NULL_TREE;
diff --git a/gcc/gimple-range.cc b/gcc/gimple-range.cc
index 6eb3f71bbd3..85ef9745593 100644
--- a/gcc/gimple-range.cc
+++ b/gcc/gimple-range.cc
@@ -180,6 +180,10 @@ gimple_ranger::range_on_edge (irange &r, edge e, tree name)
int_range_max edge_range;
gcc_checking_assert (irange::supports_type_p (TREE_TYPE (name)));
+ // Do not process values along abnormal or EH edges.
+ if (e->flags & (EDGE_ABNORMAL|EDGE_EH))
+ return false;
+
unsigned idx;
if ((idx = tracer.header ("range_on_edge (")))
{
diff --git a/gcc/gimple-ssa-evrp.c b/gcc/gimple-ssa-evrp.c
index 437f19471f1..7f2055501a0 100644
--- a/gcc/gimple-ssa-evrp.c
+++ b/gcc/gimple-ssa-evrp.c
@@ -137,6 +137,9 @@ public:
tree value_of_expr (tree name, gimple *s = NULL) OVERRIDE
{
+ // Shortcircuit subst_and_fold callbacks for abnormal ssa_names.
+ if (TREE_CODE (name) == SSA_NAME && SSA_NAME_OCCURS_IN_ABNORMAL_PHI (name))
+ return NULL;
tree ret = m_ranger->value_of_expr (name, s);
if (!ret && supported_pointer_equiv_p (name))
ret = m_pta->get_equiv (name);
@@ -145,6 +148,9 @@ public:
tree value_on_edge (edge e, tree name) OVERRIDE
{
+ // Shortcircuit subst_and_fold callbacks for abnormal ssa_names.
+ if (TREE_CODE (name) == SSA_NAME && SSA_NAME_OCCURS_IN_ABNORMAL_PHI (name))
+ return NULL;
tree ret = m_ranger->value_on_edge (e, name);
if (!ret && supported_pointer_equiv_p (name))
ret = m_pta->get_equiv (name);
@@ -153,6 +159,9 @@ public:
tree value_of_stmt (gimple *s, tree name = NULL) OVERRIDE
{
+ // Shortcircuit subst_and_fold callbacks for abnormal ssa_names.
+ if (TREE_CODE (name) == SSA_NAME && SSA_NAME_OCCURS_IN_ABNORMAL_PHI (name))
+ return NULL;
return m_ranger->value_of_stmt (s, name);
}
@@ -283,9 +292,15 @@ tree
hybrid_folder::value_of_expr (tree op, gimple *stmt)
{
tree evrp_ret = evrp_folder::value_of_expr (op, stmt);
- tree ranger_ret = m_ranger->value_of_expr (op, stmt);
- if (!ranger_ret && supported_pointer_equiv_p (op))
- ranger_ret = m_pta->get_equiv (op);
+ tree ranger_ret;
+ if (TREE_CODE (op) == SSA_NAME && SSA_NAME_OCCURS_IN_ABNORMAL_PHI (op))
+ ranger_ret = NULL;
+ else
+ {
+ ranger_ret = m_ranger->value_of_expr (op, stmt);
+ if (!ranger_ret && supported_pointer_equiv_p (op))
+ ranger_ret = m_pta->get_equiv (op);
+ }
return choose_value (evrp_ret, ranger_ret);
}
@@ -295,9 +310,15 @@ hybrid_folder::value_on_edge (edge e, tree op)
// Call evrp::value_of_expr directly. Otherwise another dual call is made
// via hybrid_folder::value_of_expr, but without an edge.
tree evrp_ret = evrp_folder::value_of_expr (op, NULL);
- tree ranger_ret = m_ranger->value_on_edge (e, op);
- if (!ranger_ret && supported_pointer_equiv_p (op))
- ranger_ret = m_pta->get_equiv (op);
+ tree ranger_ret;
+ if (TREE_CODE (op) == SSA_NAME && SSA_NAME_OCCURS_IN_ABNORMAL_PHI (op))
+ ranger_ret = NULL;
+ else
+ {
+ ranger_ret = m_ranger->value_on_edge (e, op);
+ if (!ranger_ret && supported_pointer_equiv_p (op))
+ ranger_ret = m_pta->get_equiv (op);
+ }
return choose_value (evrp_ret, ranger_ret);
}
@@ -312,7 +333,11 @@ hybrid_folder::value_of_stmt (gimple *stmt, tree op)
else
evrp_ret = NULL_TREE;
- tree ranger_ret = m_ranger->value_of_stmt (stmt, op);
+ tree ranger_ret;
+ if (op && TREE_CODE (op) == SSA_NAME && SSA_NAME_OCCURS_IN_ABNORMAL_PHI (op))
+ ranger_ret = NULL;
+ else
+ ranger_ret = m_ranger->value_of_stmt (stmt, op);
return choose_value (evrp_ret, ranger_ret);
}
diff --git a/gcc/value-query.cc b/gcc/value-query.cc
index 730a2149275..ab133aab114 100644
--- a/gcc/value-query.cc
+++ b/gcc/value-query.cc
@@ -416,8 +416,9 @@ get_range_global (irange &r, tree name)
value_range
gimple_range_global (tree name)
{
- gcc_checking_assert (gimple_range_ssa_p (name));
tree type = TREE_TYPE (name);
+ gcc_checking_assert (TREE_CODE (name) == SSA_NAME
+ && irange::supports_type_p (type));
if (SSA_NAME_IS_DEFAULT_DEF (name) || (cfun && cfun->after_inlining)
|| is_a<gphi *> (SSA_NAME_DEF_STMT (name)))
--
2.17.2
