re PR tree-optimization/16867 (Inline array initializer miscompilation at -O)

	PR tree-optimization/16867
	* tree.c (is_global_var): New function.
	(needs_to_live_in_memory): Check for TREE_ADDRESSABLE.
	Call is_global_var.
	* tree.h (DECL_NEEDS_TO_LIVE_IN_MEMORY_INTERNAL): Remove.
	Update all users.
	(is_global_var): Declare.
	* tree-dfa.c (dump_variable): Display global and addressable
	attributes.
	(add_referenced_var): Clarify documentation when marking
	variables call-clobbered.
	* tree-flow-inline.h (is_call_clobbered): Call is_global_var
	instead of needs_to_live_in_memory.
	(mark_call_clobbered): If the variable is a tag, mark it
	DECL_EXTERNAL.
	* tree-gimple.c (is_gimple_reg): Don't check for
	TREE_ADDRESSABLE.
	(is_gimple_non_addressable): Likewise.
	* tree-ssa-alias.c (get_nmt_for): Always check whether the tag
	needs to be marked call-clobbered.
	(setup_pointers_and_addressables): Call is_global_var instead
	of needs_to_live_in_memory.
	* tree-ssa-dce.c (need_to_preserve_store): Remove.
	Update all users with is_global_var.
	(mark_stmt_if_obviously_necessary): Fix processing of aliased
	stores.  Don't check the virtual definitions.  Rather, check
	whether the store is going into global memory.
	(find_obviously_necessary_stmts): Get the symbol from the PHI
	result.
	* tree-ssa-operands.c (get_call_expr_operands): Do not add
	clobbering may-defs if the call does not have side effects.


libjava/ChangeLog

	PR tree-optimization/16867
	* testsuite/libjava.lang/PR16867.java: New test.

From-SVN: r85874

1 files changed, 7 insertions, 4 deletions

diff --git a/gcc/tree-flow-inline.h b/gcc/tree-flow-inline.h
index d3e0a32..a9cc213 100644
--- a/gcc/tree-flow-inline.h
+++ b/gcc/tree-flow-inline.h
@@ -630,7 +630,7 @@ loop_containing_stmt (tree stmt)
 static inline bool
 is_call_clobbered (tree var)
 {
-  return needs_to_live_in_memory (var)
+  return is_global_var (var)
 	 || bitmap_bit_p (call_clobbered_vars, var_ann (var)->uid);
 }
 
@@ -639,8 +639,12 @@ static inline void
 mark_call_clobbered (tree var)
 {
   var_ann_t ann = var_ann (var);
-  /* Call-clobbered variables need to live in memory.  */
-  DECL_NEEDS_TO_LIVE_IN_MEMORY_INTERNAL (var) = 1;
+  /* If VAR is a memory tag, then we need to consider it a global
+     variable.  This is because the pointer that VAR represents has
+     been found to point to either an arbitrary location or to a known
+     location in global memory.  */
+  if (ann->mem_tag_kind != NOT_A_TAG)
+    DECL_EXTERNAL (var) = 1;
   bitmap_set_bit (call_clobbered_vars, ann->uid);
 }
 
@@ -649,7 +653,6 @@ static inline void
 mark_non_addressable (tree var)
 {
   bitmap_clear_bit (call_clobbered_vars, var_ann (var)->uid);
-  DECL_NEEDS_TO_LIVE_IN_MEMORY_INTERNAL (var) = 0;
   TREE_ADDRESSABLE (var) = 0;
 }