re PR tree-optimization/89505 (LibreOffice miscompilation starting with r260383)

2019-02-26  Richard Biener  <rguenther@suse.de>

	PR tree-optimization/89505
	* tree-ssa-structalias.c (compute_dependence_clique): Make sure
	to handle restrict pointed-to vars with multiple subvars
	correctly.

	* gcc.dg/torture/pr89505.c: New testcase.

From-SVN: r269212

gcc/ChangeLog

 2019-02-26  Richard Biener  <rguenther@suse.de>
 
+	PR tree-optimization/89505
+	* tree-ssa-structalias.c (compute_dependence_clique): Make sure
+	to handle restrict pointed-to vars with multiple subvars
+	correctly.
+
+2019-02-26  Richard Biener  <rguenther@suse.de>
+
 	PR tree-optimization/89489
 	* tree-parloops.c (create_loop_fn): Copy over last_clique.
 

gcc/testsuite/ChangeLog

+2019-02-26  Richard Biener  <rguenther@suse.de>
+
+	PR tree-optimization/89505
+	* gcc.dg/torture/pr89505.c: New testcase.
+
 2019-02-26  Eric Botcazou  <ebotcazou@adacore.com>
 
 	* gnat.dg/opt77.adb: New test.

gcc/testsuite/gcc.dg/torture/pr89505.c

+/* { dg-do run } */
+
+struct S { int i; void *p; int j; };
+int a;
+int __attribute__((noinline))
+foo (struct S * __restrict p, int q)
+{
+  int *x = &p->j;
+  if (q)
+    x = &a;
+  p->j = 1;
+  *x = 2;
+  return p->j;
+}
+
+int main()
+{
+  struct S s;
+  if (foo (&s, 0) != 2)
+    __builtin_abort ();
+  return 0;
+}

gcc/tree-ssa-structalias.c

@@ -7613,7 +7613,10 @@ compute_dependence_clique (void)
 					      maybe_set_dependence_info);
 	  if (used)
 	    {
-	      bitmap_set_bit (rvars, restrict_var->id);
+	      /* Add all subvars to the set of restrict pointed-to set. */
+	      for (unsigned sv = restrict_var->head; sv != 0;
+		   sv = get_varinfo (sv)->next)
+		bitmap_set_bit (rvars, sv);
 	      varinfo_t escaped = get_varinfo (find (escaped_id));
 	      if (bitmap_bit_p (escaped->solution, restrict_var->id))
 		escaped_p = true;