re PR c++/86569 (-Wnonnull-compare affects code generation since r233684)

	PR c++/86569
	* cp-gimplify.c (cp_fold): Don't fold comparisons into other kind
	of expressions other than INTEGER_CST regardless of TREE_NO_WARNING
	or warn_nonnull_compare.

	* g++.dg/warn/Wnonnull-compare-9.C: New test.

From-SVN: r262928

gcc/cp/ChangeLog

+2018-07-23  Jakub Jelinek  <jakub@redhat.com>
+
+	PR c++/86569
+	* cp-gimplify.c (cp_fold): Don't fold comparisons into other kind
+	of expressions other than INTEGER_CST regardless of TREE_NO_WARNING
+	or warn_nonnull_compare.
+
 2018-07-19  Paolo Carlini  <paolo.carlini@oracle.com>
 
 	Revert fix for c++/59480 (and testsuite followup)

gcc/cp/cp-gimplify.c

@@ -2381,21 +2381,26 @@ cp_fold (tree x)
       else
 	x = fold (x);
 
-      if (TREE_NO_WARNING (org_x)
-	  && warn_nonnull_compare
-	  && COMPARISON_CLASS_P (org_x))
+      /* This is only needed for -Wnonnull-compare and only if
+	 TREE_NO_WARNING (org_x), but to avoid that option affecting code
+	 generation, we do it always.  */
+      if (COMPARISON_CLASS_P (org_x))
 	{
 	  if (x == error_mark_node || TREE_CODE (x) == INTEGER_CST)
 	    ;
 	  else if (COMPARISON_CLASS_P (x))
-	    TREE_NO_WARNING (x) = 1;
+	    {
+	      if (TREE_NO_WARNING (org_x) && warn_nonnull_compare)
+		TREE_NO_WARNING (x) = 1;
+	    }
 	  /* Otherwise give up on optimizing these, let GIMPLE folders
 	     optimize those later on.  */
 	  else if (op0 != TREE_OPERAND (org_x, 0)
 		   || op1 != TREE_OPERAND (org_x, 1))
 	    {
 	      x = build2_loc (loc, code, TREE_TYPE (org_x), op0, op1);
-	      TREE_NO_WARNING (x) = 1;
+	      if (TREE_NO_WARNING (org_x) && warn_nonnull_compare)
+		TREE_NO_WARNING (x) = 1;
 	    }
 	  else
 	    x = org_x;

gcc/testsuite/ChangeLog

+2018-07-23  Jakub Jelinek  <jakub@redhat.com>
+
+	PR c++/86569
+	* g++.dg/warn/Wnonnull-compare-9.C: New test.
+
 2018-07-20  Martin Sebor  <msebor@redhat.com>
 
 	PR middle-end/82063

gcc/testsuite/g++.dg/warn/Wnonnull-compare-9.C

+// PR c++/86569
+// { dg-do compile }
+// { dg-options "-fcompare-debug=-Wnonnull-compare" }
+
+bool b;
+
+int
+main ()
+{
+  return ((!b) != 0);
+}