From: Andrew MacLeod <amacleod@redhat.com>
Date: Mon, 19 Oct 2020 23:04:40 +0000 (-0400)
Subject: Use precision and sign to compare types for ranges
X-Git-Url: https://git.libre-soc.org/?a=commitdiff_plain;h=6e02de946125c36871bd4d8eff21f7f88f01a8aa;p=gcc.git

Use precision and sign to compare types for ranges

Sanity check ranges by comparing just SIGN and PRECISION.

	gcc/
	PR tree-optimization/97360
	* gimple-range.h (range_compatible_p): New.
	* gimple-range-gori.cc (is_gimple_logical_p): Use range_compatible_p.
	(range_is_either_true_or_false): Ditto.
	(gori_compute::outgoing_edge_range_p): Cast result to the correct
	type if necessary.
	(logical_stmt_cache::cacheable_p): Use range_compatible_p.
	* gimple-range.cc (gimple_ranger::calc_stmt): Check range_compatible_p
	before casting the range.
	(gimple_ranger::range_on_exit): Use range_compatible_p.
	(gimple_ranger::range_on_edge): Ditto.

	gcc/testsuite/
	* gcc.dg/pr97360-2.c: New test.
---

diff --git a/gcc/gimple-range-gori.cc b/gcc/gimple-range-gori.cc
index c4bfc658319..983f4c97e87 100644
--- a/gcc/gimple-range-gori.cc
+++ b/gcc/gimple-range-gori.cc
@@ -552,7 +552,7 @@ is_gimple_logical_p (const gimple *gs)
 	case BIT_AND_EXPR:
 	case BIT_IOR_EXPR:
 	  // Bitwise operations on single bits are logical too.
-	  if (types_compatible_p (TREE_TYPE (gimple_assign_rhs1 (gs)),
+	  if (range_compatible_p (TREE_TYPE (gimple_assign_rhs1 (gs)),
 				  boolean_type_node))
 	    return true;
 	  break;
@@ -618,7 +618,7 @@ range_is_either_true_or_false (const irange &r)
   // This is complicated by the fact that Ada has multi-bit booleans,
   // so true can be ~[0, 0] (i.e. [1,MAX]).
   tree type = r.type ();
-  gcc_checking_assert (types_compatible_p (type, boolean_type_node));
+  gcc_checking_assert (range_compatible_p (type, boolean_type_node));
   return (r.singleton_p () || !r.contains_p (build_zero_cst (type)));
 }
 
@@ -999,11 +999,20 @@ gori_compute::outgoing_edge_range_p (irange &r, edge e, tree name)
 
   // If NAME can be calculated on the edge, use that.
   if (m_gori_map->is_export_p (name, e->src))
-    return compute_operand_range (r, stmt, lhs, name);
-
-  // Otherwise see if NAME is derived from something that can be
-  // calculated.  This performs no dynamic lookups whatsover, so it is
-  // low cost.
+    {
+      if (compute_operand_range (r, stmt, lhs, name))
+	{
+	  // Sometimes compatible types get interchanged. See PR97360.
+	  // Make sure we are returning the type of the thing we asked for.
+	  if (!r.undefined_p () && r.type () != TREE_TYPE (name))
+	    {
+	      gcc_checking_assert (range_compatible_p (r.type (),
+						       TREE_TYPE (name)));
+	      range_cast (r, TREE_TYPE (name));
+	    }
+	  return true;
+	}
+    }
   return false;
 }
 
@@ -1156,7 +1165,7 @@ bool
 logical_stmt_cache::cacheable_p (gimple *stmt, const irange *lhs_range) const
 {
   if (gimple_code (stmt) == GIMPLE_ASSIGN
-      && types_compatible_p (TREE_TYPE (gimple_assign_lhs (stmt)),
+      && range_compatible_p (TREE_TYPE (gimple_assign_lhs (stmt)),
 			     boolean_type_node)
       && TREE_CODE (gimple_assign_rhs1 (stmt)) == SSA_NAME)
     {
diff --git a/gcc/gimple-range.cc b/gcc/gimple-range.cc
index 999d631c5ee..e4864ba60f6 100644
--- a/gcc/gimple-range.cc
+++ b/gcc/gimple-range.cc
@@ -392,8 +392,14 @@ gimple_ranger::calc_stmt (irange &r, gimple *s, tree name)
     {
       if (r.undefined_p ())
 	return true;
+      // We sometimes get compatible types copied from operands, make sure
+      // the correct type is being returned.
       if (name && TREE_TYPE (name) != r.type ())
-	range_cast (r, TREE_TYPE (name));
+	{
+	  gcc_checking_assert (range_compatible_p (r.type (),
+						   TREE_TYPE (name)));
+	  range_cast (r, TREE_TYPE (name));
+	}
       return true;
     }
   return false;
@@ -928,7 +934,7 @@ gimple_ranger::range_on_exit (irange &r, basic_block bb, tree name)
   else
     gcc_assert (range_of_expr (r, name, s));
   gcc_checking_assert (r.undefined_p ()
-		       || types_compatible_p (r.type(), TREE_TYPE (name)));
+		       || range_compatible_p (r.type (), TREE_TYPE (name)));
 }
 
 // Calculate a range for NAME on edge E and return it in R.
@@ -948,7 +954,7 @@ gimple_ranger::range_on_edge (irange &r, edge e, tree name)
 
   range_on_exit (r, e->src, name);
   gcc_checking_assert  (r.undefined_p ()
-			|| types_compatible_p (r.type(), TREE_TYPE (name)));
+			|| range_compatible_p (r.type(), TREE_TYPE (name)));
 
   // Check to see if NAME is defined on edge e.
   if (m_cache.outgoing_edge_range_p (edge_range, e, name))
diff --git a/gcc/gimple-range.h b/gcc/gimple-range.h
index 041dc7c2a97..a6e8793f284 100644
--- a/gcc/gimple-range.h
+++ b/gcc/gimple-range.h
@@ -115,6 +115,18 @@ gimple_range_ssa_p (tree exp)
   return NULL_TREE;
 }
 
+// Return true if TYPE1 and TYPE2 are compatible range types.
+
+static inline bool
+range_compatible_p (tree type1, tree type2)
+{
+  // types_compatible_p requires conversion in both directions to be useless.
+  // GIMPLE only requires a cast one way in order to be compatible.
+  // Ranges really only need the sign and precision to be the same.
+  return (TYPE_PRECISION (type1) == TYPE_PRECISION (type2)
+	  && TYPE_SIGN (type1) == TYPE_SIGN (type2));
+}
+
 // Return the legacy GCC global range for NAME if it has one, otherwise
 // return VARYING.
 
diff --git a/gcc/testsuite/gcc.dg/pr97360-2.c b/gcc/testsuite/gcc.dg/pr97360-2.c
new file mode 100644
index 00000000000..48aebf1b100
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/pr97360-2.c
@@ -0,0 +1,14 @@
+/* { dg-do compile } */
+/* { dg-options "-O2 " } */
+
+void *a;
+void *b(void);
+void *e(void);
+
+void *
+c() {
+  void *d;
+  if (d == b && e())
+    d = a;
+  return d;
+}