re PR tree-optimization/48134 (ICE: in refs_may_alias_p_1, at…

re PR tree-optimization/48134 (ICE: in refs_may_alias_p_1, at tree-ssa-alias.c:1085 with custom flags)

2011-03-17  Richard Guenther  <rguenther@suse.de>

	PR middle-end/48134
	* tree-ssa.c (insert_debug_temp_for_var_def): If we propagated
	a value make sure to fold the statement.

	* gcc.dg/pr48134.c: New testcase.

From-SVN: r171098

gcc/ChangeLog

+2011-03-17  Richard Guenther  <rguenther@suse.de>
+
+	PR middle-end/48134
+	* tree-ssa.c (insert_debug_temp_for_var_def): If we propagated
+	a value make sure to fold the statement.
+
 2011-03-17  Chung-Lin Tang  <cltang@codesourcery.com>
 
 	PR target/43872

gcc/testsuite/ChangeLog

 2011-03-17  Richard Guenther  <rguenther@suse.de>
 
+	PR middle-end/48134
+	* gcc.dg/pr48134.c: New testcase.
+
+2011-03-17  Richard Guenther  <rguenther@suse.de>
+
 	PR middle-end/48165
 	* g++.dg/torture/pr48165.C: New testcase.
 

gcc/testsuite/gcc.dg/pr48134.c

+/* { dg-do compile } */
+/* { dg-options "-O2 -fstack-check=specific -fno-tree-dse -fno-tree-fre -fno-tree-loop-optimize -g" } */
+
+struct S
+{
+  int w, z;
+};
+struct T
+{
+  struct S s;
+};
+
+int i;
+
+static inline struct S
+bar (struct S x)
+{
+  i++;
+  return x;
+}
+
+int
+foo (struct T t, struct S s)
+{
+  struct S *c = &s;
+  if (i)
+    c = &t.s;
+  t.s.w = 3;
+  s = bar (*c);
+  return t.s.w;
+}

gcc/tree-ssa.c

@@ -455,13 +455,19 @@ insert_debug_temp_for_var_def (gimple_stmt_iterator *gsi, tree var)
 	continue;
 
       if (value)
-	FOR_EACH_IMM_USE_ON_STMT (use_p, imm_iter)
-	  /* unshare_expr is not needed here.  vexpr is either a
-	     SINGLE_RHS, that can be safely shared, some other RHS
-	     that was unshared when we found it had a single debug
-	     use, or a DEBUG_EXPR_DECL, that can be safely
-	     shared.  */
-	  SET_USE (use_p, value);
+	{
+	  FOR_EACH_IMM_USE_ON_STMT (use_p, imm_iter)
+	    /* unshare_expr is not needed here.  vexpr is either a
+	       SINGLE_RHS, that can be safely shared, some other RHS
+	       that was unshared when we found it had a single debug
+	       use, or a DEBUG_EXPR_DECL, that can be safely
+	       shared.  */
+	    SET_USE (use_p, value);
+	  /* If we didn't replace uses with a debug decl fold the
+	     resulting expression.  Otherwise we end up with invalid IL.  */
+	  if (TREE_CODE (value) != DEBUG_EXPR_DECL)
+	    fold_stmt_inplace (stmt);
+	}
       else
 	gimple_debug_bind_reset_value (stmt);