[gcc r12-2323] Abstract out non_null adjustments in ranger.

[gcc r12-2323] Abstract out non_null adjustments in ranger.

[Aldy Hernandez]

https://gcc.gnu.org/g:79f71ec6fca0e093d27cb238d7c75dccb3a55d65

commit r12-2323-g79f71ec6fca0e093d27cb238d7c75dccb3a55d65
Author: Aldy Hernandez <aldyh@redhat.com>
Date:   Thu Jul 15 12:38:36 2021 +0200

    Abstract out non_null adjustments in ranger.
    
    There are 4 exact copies of the non-null range adjusting code in the
    ranger.  This patch abstracts the functionality into a separate method.
    
    As a follow-up I would like to remove the varying_p check, since I have
    seen incoming ranges such as [0, 0xff....ef] which are not varying, but
    are not-null.  Removing the varying restriction catches those.
    
    gcc/ChangeLog:
    
            * gimple-range-cache.cc (non_null_ref::adjust_range): New.
            (ranger_cache::range_of_def): Call adjust_range.
            (ranger_cache::entry_range): Same.
            * gimple-range-cache.h (non_null_ref::adjust_range): New.
            * gimple-range.cc (gimple_ranger::range_of_expr): Call
            adjust_range.
            (gimple_ranger::range_on_entry): Same.

Diff:
---
 gcc/gimple-range-cache.cc | 35 ++++++++++++++++++++++++++---------
 gcc/gimple-range-cache.h  |  2 ++
 gcc/gimple-range.cc       |  8 ++------
 3 files changed, 30 insertions(+), 15 deletions(-)

diff --git a/gcc/gimple-range-cache.cc b/gcc/gimple-range-cache.cc
index 98ecdbbd68e..23597ade802 100644
--- a/gcc/gimple-range-cache.cc
+++ b/gcc/gimple-range-cache.cc
@@ -81,6 +81,29 @@ non_null_ref::non_null_deref_p (tree name, basic_block bb, bool search_dom)
   return false;
 }
 
+// If NAME has a non-null dereference in block BB, adjust R with the
+// non-zero information from non_null_deref_p, and return TRUE.  If
+// SEARCH_DOM is true, non_null_deref_p should search the dominator tree.
+
+bool
+non_null_ref::adjust_range (irange &r, tree name, basic_block bb,
+			    bool search_dom)
+{
+  // Check if pointers have any non-null dereferences.  Non-call
+  // exceptions mean we could throw in the middle of the block, so just
+  // punt for now on those.
+  if (!cfun->can_throw_non_call_exceptions
+      && r.varying_p ()
+      && non_null_deref_p (name, bb, search_dom))
+    {
+      int_range<2> nz;
+      nz.set_nonzero (TREE_TYPE (name));
+      r.intersect (nz);
+      return true;
+    }
+  return false;
+}
+
 // Allocate an populate the bitmap for NAME.  An ON bit for a block
 // index indicates there is a non-null reference in that block.  In
 // order to populate the bitmap, a quick run of all the immediate uses
@@ -857,9 +880,8 @@ ranger_cache::range_of_def (irange &r, tree name, basic_block bb)
 	r = gimple_range_global (name);
     }
 
-  if (bb && r.varying_p () && m_non_null.non_null_deref_p (name, bb, false) &&
-      !cfun->can_throw_non_call_exceptions)
-    r = range_nonzero (TREE_TYPE (name));
+  if (bb)
+    m_non_null.adjust_range (r, name, bb, false);
 }
 
 // Get the range of NAME as it occurs on entry to block BB.
@@ -878,12 +900,7 @@ ranger_cache::entry_range (irange &r, tree name, basic_block bb)
   if (!m_on_entry.get_bb_range (r, name, bb))
     range_of_def (r, name);
 
-  // Check if pointers have any non-null dereferences.  Non-call
-  // exceptions mean we could throw in the middle of the block, so just
-  // punt for now on those.
-  if (r.varying_p () && m_non_null.non_null_deref_p (name, bb, false) &&
-      !cfun->can_throw_non_call_exceptions)
-    r = range_nonzero (TREE_TYPE (name));
+  m_non_null.adjust_range (r, name, bb, false);
 }
 
 // Get the range of NAME as it occurs on exit from block BB.
diff --git a/gcc/gimple-range-cache.h b/gcc/gimple-range-cache.h
index ecf63dc01b3..f842e9c092a 100644
--- a/gcc/gimple-range-cache.h
+++ b/gcc/gimple-range-cache.h
@@ -34,6 +34,8 @@ public:
   non_null_ref ();
   ~non_null_ref ();
   bool non_null_deref_p (tree name, basic_block bb, bool search_dom = true);
+  bool adjust_range (irange &r, tree name, basic_block bb,
+		     bool search_dom = true);
 private:
   vec <bitmap> m_nn;
   void process_name (tree name);
diff --git a/gcc/gimple-range.cc b/gcc/gimple-range.cc
index 1851339c528..b210787d0b7 100644
--- a/gcc/gimple-range.cc
+++ b/gcc/gimple-range.cc
@@ -69,9 +69,7 @@ gimple_ranger::range_of_expr (irange &r, tree expr, gimple *stmt)
   if (def_stmt && gimple_bb (def_stmt) == bb)
     {
       range_of_stmt (r, def_stmt, expr);
-      if (!cfun->can_throw_non_call_exceptions && r.varying_p () &&
-	  m_cache.m_non_null.non_null_deref_p (expr, bb))
-	r = range_nonzero (TREE_TYPE (expr));
+      m_cache.m_non_null.adjust_range (r, expr, bb, true);
     }
   else
     // Otherwise OP comes from outside this block, use range on entry.
@@ -95,9 +93,7 @@ gimple_ranger::range_on_entry (irange &r, basic_block bb, tree name)
   if (m_cache.block_range (entry_range, bb, name))
     r.intersect (entry_range);
 
-  if (!cfun->can_throw_non_call_exceptions && r.varying_p () &&
-      m_cache.m_non_null.non_null_deref_p (name, bb))
-    r = range_nonzero (TREE_TYPE (name));
+  m_cache.m_non_null.adjust_range (r, name, bb, true);
 }
 
 // Calculate the range for NAME at the end of block BB and return it in R.