[COMMITTED] path solver: Only compute relations for imports.

Aldy Hernandez aldyh@redhat.com
Thu Nov 4 14:39:46 GMT 2021


We are currently calculating implicit PHI relations for all PHI
arguments.  This creates unecessary work, as we only care about SSA
names in the import bitmap.  Similarly for inter-path relationals.  We
can avoid things not in the bitmap.

Tested on x86-64 and ppc64le Linux with the usual regstrap.  I also
verified that the before and after number of threads was the same
in a suite of .ii files from a bootstrap.

gcc/ChangeLog:

	PR tree-optimization/102943
	* gimple-range-path.cc (path_range_query::compute_phi_relations):
	Only compute relations for SSA names in the import list.
	(path_range_query::compute_outgoing_relations): Same.
	* gimple-range-path.h (path_range_query::import_p): New.
---
 gcc/gimple-range-path.cc |  7 ++++++-
 gcc/gimple-range-path.h  | 10 ++++++++++
 2 files changed, 16 insertions(+), 1 deletion(-)

diff --git a/gcc/gimple-range-path.cc b/gcc/gimple-range-path.cc
index d8c2a9b6a86..42309886c94 100644
--- a/gcc/gimple-range-path.cc
+++ b/gcc/gimple-range-path.cc
@@ -678,8 +678,12 @@ path_range_query::compute_phi_relations (basic_block bb, basic_block prev)
        gsi_next (&iter))
     {
       gphi *phi = iter.phi ();
+      tree result = gimple_phi_result (phi);
       unsigned nargs = gimple_phi_num_args (phi);
 
+      if (!import_p (result))
+	continue;
+
       for (size_t i = 0; i < nargs; ++i)
 	if (e_in == gimple_phi_arg_edge (phi, i))
 	  {
@@ -701,7 +705,8 @@ path_range_query::compute_outgoing_relations (basic_block bb, basic_block next)
 
   if (stmt
       && gimple_code (stmt) == GIMPLE_COND
-      && irange::supports_type_p (TREE_TYPE (gimple_cond_lhs (stmt))))
+      && (import_p (gimple_cond_lhs (stmt))
+	  || import_p (gimple_cond_rhs (stmt))))
     {
       int_range<2> r;
       gcond *cond = as_a<gcond *> (stmt);
diff --git a/gcc/gimple-range-path.h b/gcc/gimple-range-path.h
index 541613956e1..f21d07f71c4 100644
--- a/gcc/gimple-range-path.h
+++ b/gcc/gimple-range-path.h
@@ -62,6 +62,7 @@ private:
   void maybe_register_phi_relation (gphi *, tree arg);
   void add_copies_to_imports ();
   bool add_to_imports (tree name, bitmap imports);
+  inline bool import_p (tree name);
 
   // Path navigation.
   void set_path (const vec<basic_block> &);
@@ -97,4 +98,13 @@ private:
   bool m_undefined_path;
 };
 
+// Return TRUE if NAME is in the import bitmap.
+
+bool
+path_range_query::import_p (tree name)
+{
+  return (TREE_CODE (name) == SSA_NAME
+	  && bitmap_bit_p (m_imports, SSA_NAME_VERSION (name)));
+}
+
 #endif // GCC_TREE_SSA_THREADSOLVER_H
-- 
2.31.1



More information about the Gcc-patches mailing list