/* Copy propagation and SSA_NAME replacement support routines.
- Copyright (C) 2004, 2005, 2007 Free Software Foundation, Inc.
+ Copyright (C) 2004, 2005, 2006, 2007, 2008 Free Software Foundation, Inc.
This file is part of GCC.
tree type_d = TREE_TYPE (dest);
tree type_o = TREE_TYPE (orig);
+ /* If ORIG flows in from an abnormal edge, it cannot be propagated. */
+ if (TREE_CODE (orig) == SSA_NAME
+ && SSA_NAME_OCCURS_IN_ABNORMAL_PHI (orig))
+ return false;
+
+ /* If DEST is an SSA_NAME that flows from an abnormal edge, then it
+ cannot be replaced. */
+ if (TREE_CODE (dest) == SSA_NAME
+ && SSA_NAME_OCCURS_IN_ABNORMAL_PHI (dest))
+ return false;
+
/* For memory partitions, copies are OK as long as the memory symbol
belongs to the partition. */
if (TREE_CODE (dest) == SSA_NAME
tree mt_orig = symbol_mem_tag (SSA_NAME_VAR (orig));
if (mt_dest && mt_orig && mt_dest != mt_orig)
return false;
- else if (!useless_type_conversion_p (type_d, type_o))
- return false;
else if (get_alias_set (TREE_TYPE (type_d)) !=
get_alias_set (TREE_TYPE (type_o)))
return false;
+ else if (!MTAG_P (SSA_NAME_VAR (dest))
+ && !MTAG_P (SSA_NAME_VAR (orig))
+ && (DECL_NO_TBAA_P (SSA_NAME_VAR (dest))
+ != DECL_NO_TBAA_P (SSA_NAME_VAR (orig))))
+ return false;
/* Also verify flow-sensitive information is compatible. */
if (SSA_NAME_PTR_INFO (orig) && SSA_NAME_PTR_INFO (dest))
return false;
}
- /* If ORIG flows in from an abnormal edge, it cannot be propagated. */
- if (TREE_CODE (orig) == SSA_NAME
- && SSA_NAME_OCCURS_IN_ABNORMAL_PHI (orig))
- return false;
-
- /* If DEST is an SSA_NAME that flows from an abnormal edge, then it
- cannot be replaced. */
- if (TREE_CODE (dest) == SSA_NAME
- && SSA_NAME_OCCURS_IN_ABNORMAL_PHI (dest))
- return false;
-
/* Anything else is OK. */
return true;
}
return;
}
- gcc_assert (POINTER_TYPE_P (TREE_TYPE (orig_name)));
- gcc_assert (POINTER_TYPE_P (TREE_TYPE (new_name)));
+ gcc_assert (POINTER_TYPE_P (TREE_TYPE (orig_name))
+ && POINTER_TYPE_P (TREE_TYPE (new_name)));
#if defined ENABLE_CHECKING
gcc_assert (useless_type_conversion_p (TREE_TYPE (orig_name),
TREE_TYPE (new_name)));
- /* If the pointed-to alias sets are different, these two pointers
- would never have the same memory tag. In this case, NEW should
- not have been propagated into ORIG. */
- gcc_assert (get_alias_set (TREE_TYPE (TREE_TYPE (new_sym)))
- == get_alias_set (TREE_TYPE (TREE_TYPE (orig_sym))));
-#endif
-
- /* Synchronize the symbol tags. If both pointers had a tag and they
- are different, then something has gone wrong. Symbol tags can
- always be merged because they are flow insensitive, all the SSA
- names of the same base DECL share the same symbol tag. */
- if (new_ann->symbol_mem_tag == NULL_TREE)
- new_ann->symbol_mem_tag = orig_ann->symbol_mem_tag;
- else if (orig_ann->symbol_mem_tag == NULL_TREE)
- orig_ann->symbol_mem_tag = new_ann->symbol_mem_tag;
- else
- gcc_assert (new_ann->symbol_mem_tag == orig_ann->symbol_mem_tag);
-
/* Check that flow-sensitive information is compatible. Notice that
we may not merge flow-sensitive information here. This function
is called when propagating equivalences dictated by the IL, like
Since we cannot distinguish one case from another in this
function, we can only make sure that if P_i and Q_j have
- flow-sensitive information, they should be compatible. */
+ flow-sensitive information, they should be compatible.
+
+ As callers of merge_alias_info are supposed to call may_propagate_copy
+ first, the following check is redundant. Thus, only do it if checking
+ is enabled. */
if (SSA_NAME_PTR_INFO (orig_name) && SSA_NAME_PTR_INFO (new_name))
{
struct ptr_info_def *orig_ptr_info = SSA_NAME_PTR_INFO (orig_name);
gcc_assert (bitmap_intersect_p (new_ptr_info->pt_vars,
orig_ptr_info->pt_vars));
}
-}
+#endif
+
+ /* Synchronize the symbol tags. If both pointers had a tag and they
+ are different, then something has gone wrong. Symbol tags can
+ always be merged because they are flow insensitive, all the SSA
+ names of the same base DECL share the same symbol tag. */
+ if (new_ann->symbol_mem_tag == NULL_TREE)
+ new_ann->symbol_mem_tag = orig_ann->symbol_mem_tag;
+ else if (orig_ann->symbol_mem_tag == NULL_TREE)
+ orig_ann->symbol_mem_tag = new_ann->symbol_mem_tag;
+ else
+ gcc_assert (new_ann->symbol_mem_tag == orig_ann->symbol_mem_tag);
+
+ /* Copy flow-sensitive alias information in case that NEW_NAME
+ didn't get a NMT but was set to pt_anything for optimization
+ purposes. In case ORIG_NAME has a NMT we can safely use its
+ flow-sensitive alias information as a conservative estimate. */
+ if (SSA_NAME_PTR_INFO (orig_name)
+ && SSA_NAME_PTR_INFO (orig_name)->name_mem_tag
+ && (!SSA_NAME_PTR_INFO (new_name)
+ || !SSA_NAME_PTR_INFO (new_name)->name_mem_tag))
+ {
+ struct ptr_info_def *orig_ptr_info = SSA_NAME_PTR_INFO (orig_name);
+ struct ptr_info_def *new_ptr_info = get_ptr_info (new_name);
+ memcpy (new_ptr_info, orig_ptr_info, sizeof (struct ptr_info_def));
+ }
+}
/* Common code for propagate_value and replace_exp.
return flag_tree_copy_prop != 0;
}
-struct tree_opt_pass pass_copy_prop =
+struct gimple_opt_pass pass_copy_prop =
{
+ {
+ GIMPLE_PASS,
"copyprop", /* name */
gate_copy_prop, /* gate */
execute_copy_prop, /* execute */
| TODO_dump_func
| TODO_ggc_collect
| TODO_verify_ssa
- | TODO_update_ssa, /* todo_flags_finish */
- 0 /* letter */
+ | TODO_update_ssa /* todo_flags_finish */
+ }
};
OSDN Git Service
