re PR middle-end/87610 (wrong-code with restrict)

2018-10-15  Richard Biener  <rguenther@suse.de>

	PR middle-end/87610
	* tree-ssa-structalias.c (struct vls_data): Add escaped_p member.
	(visit_loadstore): When a used restrict tag escaped verify that
	the points-to solution of "other" pointers do not include
	escaped.
	(compute_dependence_clique): If a used restrict tag escaped
	communicated that down to visit_loadstore.

	* gcc.dg/torture/restrict-6.c: New testcase.

From-SVN: r265160

gcc/ChangeLog

@@ -1,3 +1,13 @@
+2018-10-15  Richard Biener  <rguenther@suse.de>
+
+	PR middle-end/87610
+	* tree-ssa-structalias.c (struct vls_data): Add escaped_p member.
+	(visit_loadstore): When a used restrict tag escaped verify that
+	the points-to solution of "other" pointers do not include
+	escaped.
+	(compute_dependence_clique): If a used restrict tag escaped
+	communicated that down to visit_loadstore.
+
 2018-10-15  Andreas Krebbel  <krebbel@linux.ibm.com>
 
 	* config/s390/s390.c (s390_expand_vec_init): Force vector element

gcc/testsuite/ChangeLog

@@ -1,3 +1,8 @@
+2018-10-15  Richard Biener  <rguenther@suse.de>
+
+	PR middle-end/87610
+	* gcc.dg/torture/restrict-6.c: New testcase.
+
 2018-10-15  Andreas Krebbel  <krebbel@linux.ibm.com>
 
 	* g++.dg/vec-init-1.C: New test.

gcc/testsuite/gcc.dg/torture/restrict-6.c

@@ -0,0 +1,24 @@
+/* { dg-do run } */
+
+extern void abort (void);
+
+void __attribute__((noinline)) g(int **a, int *b)
+{
+  *a = b;
+}
+
+int foo(int * restrict p, int *q)
+{
+  g(&q, p);
+  *p = 1;
+  *q = 2;
+  return *p + *q;
+}
+
+int main()
+{
+  int x, y;
+  if (foo(&x, &y) != 4)
+    abort ();
+  return 0;
+}

gcc/tree-ssa-structalias.c

@@ -7397,6 +7397,7 @@ delete_points_to_sets (void)
 struct vls_data
 {
   unsigned short clique;
+  bool escaped_p;
   bitmap rvars;
 };
 
@@ -7408,6 +7409,7 @@ visit_loadstore (gimple *, tree base, tree ref, void *data)
 {
   unsigned short clique = ((vls_data *) data)->clique;
   bitmap rvars = ((vls_data *) data)->rvars;
+  bool escaped_p = ((vls_data *) data)->escaped_p;
   if (TREE_CODE (base) == MEM_REF
       || TREE_CODE (base) == TARGET_MEM_REF)
     {
@@ -7428,7 +7430,8 @@ visit_loadstore (gimple *, tree base, tree ref, void *data)
 	    return false;
 
 	  vi = get_varinfo (find (vi->id));
-	  if (bitmap_intersect_p (rvars, vi->solution))
+	  if (bitmap_intersect_p (rvars, vi->solution)
+	      || (escaped_p && bitmap_bit_p (vi->solution, escaped_id)))
 	    return false;
 	}
 
@@ -7505,6 +7508,7 @@ compute_dependence_clique (void)
   unsigned short clique = 0;
   unsigned short last_ruid = 0;
   bitmap rvars = BITMAP_ALLOC (NULL);
+  bool escaped_p = false;
   for (unsigned i = 0; i < num_ssa_names; ++i)
     {
       tree ptr = ssa_name (i);
@@ -7574,7 +7578,12 @@ compute_dependence_clique (void)
 						 last_ruid);
 	    }
 	  if (used)
-	    bitmap_set_bit (rvars, restrict_var->id);
+	    {
+	      bitmap_set_bit (rvars, restrict_var->id);
+	      varinfo_t escaped = get_varinfo (find (escaped_id));
+	      if (bitmap_bit_p (escaped->solution, restrict_var->id))
+		escaped_p = true;
+	    }
 	}
     }
 
@@ -7587,7 +7596,7 @@ compute_dependence_clique (void)
 	 parameters) we can't restrict scoping properly thus the following
 	 is too aggressive there.  For now we have excluded those globals from
 	 getting into the MR_DEPENDENCE machinery.  */
-      vls_data data = { clique, rvars };
+      vls_data data = { clique, escaped_p, rvars };
       basic_block bb;
       FOR_EACH_BB_FN (bb, cfun)
 	for (gimple_stmt_iterator gsi = gsi_start_bb (bb);