re PR tree-optimization/42730 (ice: verify_stmts failed)

2010-01-13  Richard Guenther  <rguenther@suse.de>

	PR tree-optimization/42730
	* tree-ssa-ccp.c (maybe_fold_stmt_indirect): Add shortcut for
	offset zero.

	* gcc.c-torture/compile/pr42730.c: New testcase.

From-SVN: r155872

gcc/ChangeLog

+2010-01-13  Richard Guenther  <rguenther@suse.de>
+
+	PR tree-optimization/42730
+	* tree-ssa-ccp.c (maybe_fold_stmt_indirect): Add shortcut for
+	offset zero.
+
 2010-01-13  Steve Ellcey  <sje@cup.hp.com>
 
 	PR target/pr42542

gcc/testsuite/ChangeLog

+2010-01-13  Richard Guenther  <rguenther@suse.de>
+
+	PR tree-optimization/42730
+	* gcc.c-torture/compile/pr42730.c: New testcase.
+
 2010-01-13  Steve Ellcey  <sje@cup.hp.com>
 
 	PR target/pr42542

gcc/testsuite/gcc.c-torture/compile/pr42730.c

+union bzz
+{
+  unsigned *pa;
+  void *pv;
+};
+
+void foo (void)
+{
+  union bzz u;
+  void **x;
+  void *y = 0;
+  x = &u.pv;
+  *x = y;
+}

gcc/tree-ssa-ccp.c

@@ -2120,6 +2120,10 @@ maybe_fold_stmt_indirect (tree expr, tree base, tree offset)
 	  && is_gimple_min_invariant (DECL_INITIAL (base)))
 	return DECL_INITIAL (base);
 
+      /* If there is no offset involved simply return the folded base.  */
+      if (integer_zerop (offset))
+	return base;
+
       /* Try folding *(&B+O) to B.X.  */
       t = maybe_fold_offset_to_reference (loc, base_addr, offset,
 					  TREE_TYPE (expr));