From: Aldy Hernandez <aldyh@redhat.com>
Date: Fri, 3 Sep 2021 09:22:26 +0000 (+0200)
Subject: Use non-null knowledge in path_range_query.
X-Git-Tag: basepoints/gcc-13~4980
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=410e8742638dadc8f84db681ca7bd9c031d41446;p=thirdparty%2Fgcc.git

Use non-null knowledge in path_range_query.

This patch improves ranges for pointers we are interested in a path, by
using the non-null class from the ranger.  This allows us to thread more
paths with minimal effort.

Tested on x86-64 Linux.

gcc/ChangeLog:

	* gimple-range-path.cc (path_range_query::range_defined_in_block):
	Adjust for non-null.
	(path_range_query::adjust_for_non_null_uses): New.
	(path_range_query::precompute_ranges): Call
	adjust_for_non_null_uses.
	* gimple-range-path.h: Add m_non_null and
	adjust_for_non_null_uses.
---

diff --git a/gcc/gimple-range-path.cc b/gcc/gimple-range-path.cc
index 6d6e5eb66354..db15eb3ff227 100644
--- a/gcc/gimple-range-path.cc
+++ b/gcc/gimple-range-path.cc
@@ -221,6 +221,9 @@ path_range_query::range_defined_in_block (irange &r, tree name, basic_block bb)
   else if (!fold_range (r, def_stmt, this))
     r.set_varying (TREE_TYPE (name));
 
+  if (bb)
+    m_non_null.adjust_range (r, name, bb);
+
   if (DEBUG_SOLVER && (bb || !r.varying_p ()))
     {
       fprintf (dump_file, "range_defined_in_block (BB%d) for ", bb ? bb->index : -1);
@@ -302,6 +305,35 @@ path_range_query::precompute_ranges_in_block (basic_block bb)
     }
 }
 
+// Adjust all pointer imports in BB with non-null information.
+
+void
+path_range_query::adjust_for_non_null_uses (basic_block bb)
+{
+  int_range_max r;
+  bitmap_iterator bi;
+  unsigned i;
+
+  EXECUTE_IF_SET_IN_BITMAP (m_imports, 0, i, bi)
+    {
+      tree name = ssa_name (i);
+
+      if (!POINTER_TYPE_P (TREE_TYPE (name)))
+	continue;
+
+      if (get_cache (r, name))
+	{
+	  if (r.nonzero_p ())
+	    continue;
+	}
+      else
+	r.set_varying (TREE_TYPE (name));
+
+      if (m_non_null.adjust_range (r, name, bb))
+	set_cache (r, name);
+    }
+}
+
 // Precompute the ranges for IMPORTS along PATH.
 //
 // IMPORTS are the set of SSA names, any of which could potentially
@@ -332,6 +364,7 @@ path_range_query::precompute_ranges (const vec<basic_block> &path,
       basic_block bb = curr_bb ();
 
       precompute_ranges_in_block (bb);
+      adjust_for_non_null_uses (bb);
 
       if (at_exit ())
 	break;
diff --git a/gcc/gimple-range-path.h b/gcc/gimple-range-path.h
index 0d2d2e7f75d2..517731310402 100644
--- a/gcc/gimple-range-path.h
+++ b/gcc/gimple-range-path.h
@@ -53,6 +53,7 @@ private:
   // Methods to precompute ranges for the given path.
   bool range_defined_in_block (irange &, tree name, basic_block bb);
   void precompute_ranges_in_block (basic_block bb);
+  void adjust_for_non_null_uses (basic_block bb);
   void ssa_range_in_phi (irange &r, gphi *phi);
 
   // Path navigation.
@@ -80,6 +81,7 @@ private:
 
   const bitmap_head *m_imports;
   gimple_ranger &m_ranger;
+  non_null_ref m_non_null;
 };
 
 #endif // GCC_TREE_SSA_THREADSOLVER_H