re PR libmudflap/53952 (FAIL: libmudflap.c++/pass55-frag.cxx ( -O[123]) execution test)

PR libmudflap/53952
* expr.c (mem_ref_refers_to_non_mem_p): Factor out
implementation into...
(addr_expr_of_non_mem_decl_p_1): ... this new function.
(addr_expr_of_non_mem_decl_p): New.
* tree.h (addr_expr_of_non_mem_decl_p): Declare.
* tree-mudflap.c (mf_xform_derefs_1): Don't change MEM_REFs
and TARGET_MEM_REFs that have an ADDR_EXPR of a non-mem DECL
as base operand.

From-SVN: r194519

gcc/ChangeLog

@@ -1,3 +1,15 @@
+2012-12-15  Alexandre Oliva <aoliva@redhat.com>
+
+	PR libmudflap/53952
+	* expr.c (mem_ref_refers_to_non_mem_p): Factor out
+	implementation into...
+	(addr_expr_of_non_mem_decl_p_1): ... this new function.
+	(addr_expr_of_non_mem_decl_p): New.
+	* tree.h (addr_expr_of_non_mem_decl_p): Declare.
+	* tree-mudflap.c (mf_xform_derefs_1): Don't change MEM_REFs
+	and TARGET_MEM_REFs that have an ADDR_EXPR of a non-mem DECL
+	as base operand.
+
 2012-12-14  Yvan Roux  <yvan.roux@linaro.org>
 
 	* optabs.c (expand_atomic_store): Elide redundant model test.

gcc/expr.c

@@ -4557,21 +4557,48 @@ get_bit_range (unsigned HOST_WIDE_INT *bitstart,
   *bitend = *bitstart + tree_low_cst (DECL_SIZE (repr), 1) - 1;
 }
 
+/* Returns true if ADDR is an ADDR_EXPR of a DECL that does not reside
+   in memory and has non-BLKmode.  DECL_RTL must not be a MEM; if
+   DECL_RTL was not set yet, return NORTL.  */
+
+static inline bool
+addr_expr_of_non_mem_decl_p_1 (tree addr, bool nortl)
+{
+  if (TREE_CODE (addr) != ADDR_EXPR)
+    return false;
+
+  tree base = TREE_OPERAND (addr, 0);
+
+  if (!DECL_P (base)
+      || TREE_ADDRESSABLE (base)
+      || DECL_MODE (base) == BLKmode)
+    return false;
+
+  if (!DECL_RTL_SET_P (base))
+    return nortl;
+
+  return (!MEM_P (DECL_RTL (base)));
+}
+
 /* Returns true if the MEM_REF REF refers to an object that does not
    reside in memory and has non-BLKmode.  */
 
-static bool
+static inline bool
 mem_ref_refers_to_non_mem_p (tree ref)
 {
   tree base = TREE_OPERAND (ref, 0);
-  if (TREE_CODE (base) != ADDR_EXPR)
-    return false;
-  base = TREE_OPERAND (base, 0);
-  return (DECL_P (base)
-	  && !TREE_ADDRESSABLE (base)
-	  && DECL_MODE (base) != BLKmode
-	  && DECL_RTL_SET_P (base)
-	  && !MEM_P (DECL_RTL (base)));
+  return addr_expr_of_non_mem_decl_p_1 (base, false);
+}
+
+/* Return TRUE iff OP is an ADDR_EXPR of a DECL that's not
+   addressable.  This is very much like mem_ref_refers_to_non_mem_p,
+   but instead of the MEM_REF, it takes its base, and it doesn't
+   assume a DECL is in memory just because its RTL is not set yet.  */
+
+bool
+addr_expr_of_non_mem_decl_p (tree op)
+{
+  return addr_expr_of_non_mem_decl_p_1 (op, true);
 }
 
 /* Expand an assignment that stores the value of FROM into TO.  If NONTEMPORAL

gcc/tree-mudflap.c

@@ -877,6 +877,9 @@ mf_xform_derefs_1 (gimple_stmt_iterator *iter, tree *tp,
       break;
 
     case MEM_REF:
+      if (addr_expr_of_non_mem_decl_p (TREE_OPERAND (t, 0)))
+	return;
+
       addr = fold_build_pointer_plus_loc (location, TREE_OPERAND (t, 0),
 					  TREE_OPERAND (t, 1));
       base = addr;
@@ -886,6 +889,9 @@ mf_xform_derefs_1 (gimple_stmt_iterator *iter, tree *tp,
       break;
 
     case TARGET_MEM_REF:
+      if (addr_expr_of_non_mem_decl_p (TMR_BASE (t)))
+	return;
+
       addr = tree_mem_ref_addr (ptr_type_node, t);
       base = addr;
       limit = fold_build_pointer_plus_hwi_loc (location,

gcc/tree.h

@@ -6304,6 +6304,9 @@ extern unsigned HOST_WIDE_INT compute_builtin_object_size (tree, int);
    succeed.  */
 extern int can_move_by_pieces (unsigned HOST_WIDE_INT, unsigned int);
 
+/* Is it an ADDR_EXPR of a DECL that's not in memory?  */
+extern bool addr_expr_of_non_mem_decl_p (tree);
+
 extern unsigned HOST_WIDE_INT highest_pow2_factor (const_tree);
 extern tree build_personality_function (const char *);