The following improves on the fix for PR105142 which restricted the
expression lookup used for maybe_fold_comparisons_from_match_pd to
avoid picking up flow-sensitive info for use in places where guarding
conditions do not hold. Instead of not allowing to expand SSA
definitions there the following temporarily clears flow-sensitive
info on the SSA names and restores it when finished matching.
Bootstrapped on x86_64-unknown-linux-gnu, testing in progress.
PR tree-optimization/105142
* gimple-fold.cc (fosa_unwind): New global.
(follow_outer_ssa_edges): When the SSA definition to follow
is does not dominate fosa_bb, temporarily clear flow-sensitive
info.
(maybe_fold_comparisons_from_match_pd): Set up unwind stack
for follow_outer_ssa_edges and unwind flow-sensitive info
clearing after matching.
---
gcc/gimple-fold.cc | 19 ++++++++++++++++++-
1 file changed, 18 insertions(+), 1 deletion(-)
diff --git a/gcc/gimple-fold.cc b/gcc/gimple-fold.cc
index a1704784bc9..876ef45434e 100644
--- a/gcc/gimple-fold.cc
+++ b/gcc/gimple-fold.cc
@@ -6886,6 +6886,7 @@ and_comparisons_1 (tree type, enum tree_code code1, tree
op1a, tree op1b,
}
static basic_block fosa_bb;
+static vec<std::pair<tree, void *> > *fosa_unwind;
static tree
follow_outer_ssa_edges (tree val)
{
@@ -6899,7 +6900,15 @@ follow_outer_ssa_edges (tree val)
&& (def_bb == fosa_bb
|| dominated_by_p (CDI_DOMINATORS, fosa_bb, def_bb))))
return val;
- return NULL_TREE;
+ /* If the definition does not dominate fosa_bb temporarily reset
+ flow-sensitive info. */
+ if (val->ssa_name.info.range_info)
+ {
+ fosa_unwind->safe_push (std::make_pair
+ (val, val->ssa_name.info.range_info));
+ val->ssa_name.info.range_info = NULL;
+ }
+ return val;
}
return val;
}
@@ -6958,9 +6967,14 @@ maybe_fold_comparisons_from_match_pd (tree type, enum
tree_code code,
type, gimple_assign_lhs (stmt1),
gimple_assign_lhs (stmt2));
fosa_bb = outer_cond_bb;
+ auto_vec<std::pair<tree, void *>, 8> unwind_stack;
+ fosa_unwind = &unwind_stack;
if (op.resimplify (NULL, (!outer_cond_bb
? follow_all_ssa_edges : follow_outer_ssa_edges)))
{
+ fosa_unwind = NULL;
+ for (auto p : unwind_stack)
+ p.first->ssa_name.info.range_info = p.second;
if (gimple_simplified_result_is_gimple_val (&op))
{
tree res = op.ops[0];
@@ -6982,6 +6996,9 @@ maybe_fold_comparisons_from_match_pd (tree type, enum
tree_code code,
return build2 ((enum tree_code)op.code, op.type, op0, op1);
}
}
+ fosa_unwind = NULL;
+ for (auto p : unwind_stack)
+ p.first->ssa_name.info.range_info = p.second;
return NULL_TREE;
}
--
2.35.3
