[PATCH] Fix PR69801

[Richard Biener]

Bootstrapped and tested on x86_64-unknown-linux-gnu, applied.

Richard.

2016-02-16  Richard Biener  <rguent...@suse.de>

        PR middle-end/69801
        * fold-const.c (operand_equal_p): For COND_EXPR zero operand
        mask OEP_ADDRESS_OF.

        * gcc.dg/pr69801.c: New testcase.

Index: gcc/fold-const.c
===================================================================
*** gcc/fold-const.c    (revision 233418)
--- gcc/fold-const.c    (working copy)
*************** operand_equal_p (const_tree arg0, const_
*** 3118,3123 ****
--- 3118,3128 ----
                                      TREE_OPERAND (arg1, 0), flags));
  
        case COND_EXPR:
+         if (! OP_SAME (1) || ! OP_SAME (2))
+           return 0;
+         flags &= ~OEP_ADDRESS_OF;
+         return OP_SAME (0);
+ 
        case VEC_COND_EXPR:
        case DOT_PROD_EXPR:
          return OP_SAME (0) && OP_SAME (1) && OP_SAME (2);
Index: gcc/testsuite/gcc.dg/pr69801.c
===================================================================
*** gcc/testsuite/gcc.dg/pr69801.c      (revision 0)
--- gcc/testsuite/gcc.dg/pr69801.c      (working copy)
***************
*** 0 ****
--- 1,7 ----
+ /* { dg-do compile } */
+ 
+ struct {
+     char c[1];
+ } b, c;
+ int d, e;
+ void fn1() { e ? (d ? b : c).c : (d ? b : c).c; }