re PR middle-end/71062 (r235622 and restrict pointers)

2016-05-12  Richard Biener  <rguenther@suse.de>

	PR tree-optimization/71062
	* tree-ssa-alias.h (struct pt_solution): Add vars_contains_restrict
	field.
	* tree-ssa-structalias.c (set_uids_in_ptset): Set vars_contains_restrict
	if the var is a restrict tag.
	* tree-ssa-alias.c (ptrs_compare_unequal): If vars_contains_restrict
	do not disambiguate pointers against it.
	(dump_points_to_solution): Re-structure and adjust for new
	vars_contains_restrict flag.
	* gimple-pretty-print.c (pp_points_to_solution): Likewise.

	* gcc.dg/torture/pr71062.c: New testcase.

From-SVN: r236174

7 files changed, 106 insertions, 26 deletions

diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index 40f1b66..ddea24b 100644
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,16 @@
+2016-05-12  Richard Biener  <rguenther@suse.de>
+
+	PR tree-optimization/71062
+	* tree-ssa-alias.h (struct pt_solution): Add vars_contains_restrict
+	field.
+	* tree-ssa-structalias.c (set_uids_in_ptset): Set vars_contains_restrict
+	if the var is a restrict tag.
+	* tree-ssa-alias.c (ptrs_compare_unequal): If vars_contains_restrict
+	do not disambiguate pointers against it.
+	(dump_points_to_solution): Re-structure and adjust for new
+	vars_contains_restrict flag.
+	* gimple-pretty-print.c (pp_points_to_solution): Likewise.
+
 2016-05-12  Martin Liska  <mliska@suse.cz>
 
 	* doc/invoke.texi: Explain connection between -fsanitize-recover=address
diff --git a/gcc/gimple-pretty-print.c b/gcc/gimple-pretty-print.c
index e27214f..4b0dc7c 100644
--- a/gcc/gimple-pretty-print.c
+++ b/gcc/gimple-pretty-print.c
@@ -632,17 +632,37 @@ pp_points_to_solution (pretty_printer *buffer, struct pt_solution *pt)
 	}
       pp_right_brace (buffer);
       if (pt->vars_contains_nonlocal
-	  && pt->vars_contains_escaped_heap)
-	pp_string (buffer, " (nonlocal, escaped heap)");
-      else if (pt->vars_contains_nonlocal
-	       && pt->vars_contains_escaped)
-	pp_string (buffer, " (nonlocal, escaped)");
-      else if (pt->vars_contains_nonlocal)
-	pp_string (buffer, " (nonlocal)");
-      else if (pt->vars_contains_escaped_heap)
-	pp_string (buffer, " (escaped heap)");
-      else if (pt->vars_contains_escaped)
-	pp_string (buffer, " (escaped)");
+	  || pt->vars_contains_escaped
+	  || pt->vars_contains_escaped_heap
+	  || pt->vars_contains_restrict)
+	{
+	  const char *comma = "";
+	  pp_string (buffer, " (");
+	  if (pt->vars_contains_nonlocal)
+	    {
+	      pp_string (buffer, "nonlocal");
+	      comma = ", ";
+	    }
+	  if (pt->vars_contains_escaped)
+	    {
+	      pp_string (buffer, comma);
+	      pp_string (buffer, "escaped");
+	      comma = ", ";
+	    }
+	  if (pt->vars_contains_escaped_heap)
+	    {
+	      pp_string (buffer, comma);
+	      pp_string (buffer, "escaped heap");
+	      comma = ", ";
+	    }
+	  if (pt->vars_contains_restrict)
+	    {
+	      pp_string (buffer, comma);
+	      pp_string (buffer, "restrict");
+	    }
+	  pp_string (buffer, ")");
+	}
+
     }
 }
 
diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog
index d61bb26..6dca22f 100644
--- a/gcc/testsuite/ChangeLog
+++ b/gcc/testsuite/ChangeLog
@@ -1,3 +1,8 @@
+2016-05-12  Richard Biener  <rguenther@suse.de>
+
+	PR tree-optimization/71062
+	* gcc.dg/torture/pr71062.c: New testcase.
+
 2016-05-12  Ilya Enkovich  <ilya.enkovich@intel.com>
 
 	PR tree-optimization/71006
diff --git a/gcc/testsuite/gcc.dg/torture/pr71062.c b/gcc/testsuite/gcc.dg/torture/pr71062.c
new file mode 100644
index 0000000..cc01dda
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/torture/pr71062.c
@@ -0,0 +1,20 @@
+/* { dg-do run } */
+
+extern void abort (void);
+
+char bar;
+
+int __attribute__((noinline,noclone))
+foo (char *__restrict p)
+{
+  if (p == &bar)
+    return 1;
+  return 0;
+}
+
+int main()
+{
+  if (foo (&bar) != 1)
+    abort ();
+  return 0;
+}
diff --git a/gcc/tree-ssa-alias.c b/gcc/tree-ssa-alias.c
index 58920e0..b663ddf 100644
--- a/gcc/tree-ssa-alias.c
+++ b/gcc/tree-ssa-alias.c
@@ -363,14 +363,17 @@ ptrs_compare_unequal (tree ptr1, tree ptr2)
   else if (obj1 && TREE_CODE (ptr2) == SSA_NAME)
     {
       struct ptr_info_def *pi = SSA_NAME_PTR_INFO (ptr2);
-      if (!pi)
+      /* We may not use restrict to optimize pointer comparisons.
+         See PR71062.  So we have to assume that restrict-pointed-to
+	 may be in fact obj1.  */
+      if (!pi || pi->pt.vars_contains_restrict)
 	return false;
       return !pt_solution_includes (&pi->pt, obj1);
     }
   else if (TREE_CODE (ptr1) == SSA_NAME && obj2)
     {
       struct ptr_info_def *pi = SSA_NAME_PTR_INFO (ptr1);
-      if (!pi)
+      if (!pi || pi->pt.vars_contains_restrict)
 	return false;
       return !pt_solution_includes (&pi->pt, obj2);
     }
@@ -521,17 +524,31 @@ dump_points_to_solution (FILE *file, struct pt_solution *pt)
       fprintf (file, ", points-to vars: ");
       dump_decl_set (file, pt->vars);
       if (pt->vars_contains_nonlocal
-	  && pt->vars_contains_escaped_heap)
-	fprintf (file, " (nonlocal, escaped heap)");
-      else if (pt->vars_contains_nonlocal
-	       && pt->vars_contains_escaped)
-	fprintf (file, " (nonlocal, escaped)");
-      else if (pt->vars_contains_nonlocal)
-	fprintf (file, " (nonlocal)");
-      else if (pt->vars_contains_escaped_heap)
-	fprintf (file, " (escaped heap)");
-      else if (pt->vars_contains_escaped)
-	fprintf (file, " (escaped)");
+	  || pt->vars_contains_escaped
+	  || pt->vars_contains_escaped_heap
+	  || pt->vars_contains_restrict)
+	{
+	  const char *comma = "";
+	  fprintf (file, " (");
+	  if (pt->vars_contains_nonlocal)
+	    {
+	      fprintf (file, "nonlocal");
+	      comma = ", ";
+	    }
+	  if (pt->vars_contains_escaped)
+	    {
+	      fprintf (file, "%sescaped", comma);
+	      comma = ", ";
+	    }
+	  if (pt->vars_contains_escaped_heap)
+	    {
+	      fprintf (file, "%sescaped heap", comma);
+	      comma = ", ";
+	    }
+	  if (pt->vars_contains_restrict)
+	    fprintf (file, "%srestrict", comma);
+	  fprintf (file, ")");
+	}
     }
 }
 
diff --git a/gcc/tree-ssa-alias.h b/gcc/tree-ssa-alias.h
index 0593b05..6680cc0 100644
--- a/gcc/tree-ssa-alias.h
+++ b/gcc/tree-ssa-alias.h
@@ -47,7 +47,6 @@ struct GTY(()) pt_solution
      includes memory at address NULL.  */
   unsigned int null : 1;
 
-
   /* Nonzero if the vars bitmap includes a variable included in 'nonlocal'.  */
   unsigned int vars_contains_nonlocal : 1;
   /* Nonzero if the vars bitmap includes a variable included in 'escaped'.  */
@@ -55,6 +54,9 @@ struct GTY(()) pt_solution
   /* Nonzero if the vars bitmap includes a anonymous heap variable that
      escaped the function and thus became global.  */
   unsigned int vars_contains_escaped_heap : 1;
+  /* Nonzero if the vars bitmap includes a anonymous variable used to
+     represent storage pointed to by a restrict qualified pointer.  */
+  unsigned int vars_contains_restrict : 1;
 
   /* Set of variables that this pointer may point to.  */
   bitmap vars;
diff --git a/gcc/tree-ssa-structalias.c b/gcc/tree-ssa-structalias.c
index 3956efd..5e3c7d0 100644
--- a/gcc/tree-ssa-structalias.c
+++ b/gcc/tree-ssa-structalias.c
@@ -6254,6 +6254,9 @@ set_uids_in_ptset (bitmap into, bitmap from, struct pt_solution *pt,
 	  pt->vars_contains_escaped_heap = vi->is_heap_var;
 	}
 
+      if (vi->is_restrict_var)
+	pt->vars_contains_restrict = true;
+
       if (TREE_CODE (vi->decl) == VAR_DECL
 	  || TREE_CODE (vi->decl) == PARM_DECL
 	  || TREE_CODE (vi->decl) == RESULT_DECL)
@@ -7505,7 +7508,7 @@ make_pass_build_ealias (gcc::context *ctxt)
 
 /* IPA PTA solutions for ESCAPED.  */
 struct pt_solution ipa_escaped_pt
-  = { true, false, false, false, false, false, false, false, NULL };
+  = { true, false, false, false, false, false, false, false, false, NULL };
 
 /* Associate node with varinfo DATA. Worker for
    cgraph_for_symbol_thunks_and_aliases.  */