tree-outof-ssa.h (ssaexpand): Add partitions_for_undefined_values.

	* tree-outof-ssa.h (ssaexpand): Add partitions_for_undefined_values.
	(always_initialized_rtx_for_ssa_name_p): New predicate.
	* tree-outof-ssa.c (remove_ssa_form): Initialize new field of SA.
	(finish_out_of_ssa): Free new field of SA.
	* tree-ssa-coalesce.h (get_undefined_value_partitions): Declare.
	* tree-ssa-coalesce.c: Include tree-ssa.h.
	(get_parm_default_def_partitions): Remove extern keyword.
	(get_undefined_value_partitions): New function.
	* expr.c (expand_expr_real_1) <expand_decl_rtl>: For a SSA_NAME, do
	not set SUBREG_PROMOTED_VAR_P on the sub-register if it may contain
	uninitialized bits.
	* loop-iv.c (iv_get_reaching_def): Disqualify all subregs.

From-SVN: r253530

1 files changed, 16 insertions, 0 deletions

diff --git a/gcc/tree-outof-ssa.h b/gcc/tree-outof-ssa.h
index e751a26..1220b62 100644
--- a/gcc/tree-outof-ssa.h
+++ b/gcc/tree-outof-ssa.h
@@ -42,6 +42,10 @@ struct ssaexpand
   /* If partition I contains an SSA name that has a default def for a
      parameter, bit I will be set in this bitmap.  */
   bitmap partitions_for_parm_default_defs;
+
+  /* If partition I contains an SSA name that has an undefined value,
+     bit I will be set in this bitmap.  */
+  bitmap partitions_for_undefined_values;
 };
 
 /* This is the singleton described above.  */
@@ -70,6 +74,18 @@ get_gimple_for_ssa_name (tree exp)
   return NULL;
 }
 
+/* Return whether the RTX expression representing the storage of the outof-SSA
+   partition that the SSA name EXP is a member of is always initialized.  */
+static inline bool
+always_initialized_rtx_for_ssa_name_p (tree exp)
+{
+  int p = partition_find (SA.map->var_partition, SSA_NAME_VERSION (exp));
+  if (SA.map->partition_to_view)
+    p = SA.map->partition_to_view[p];
+  gcc_assert (p != NO_PARTITION);
+  return !bitmap_bit_p (SA.partitions_for_undefined_values, p);
+}
+
 extern bool ssa_is_replaceable_p (gimple *stmt);
 extern void finish_out_of_ssa (struct ssaexpand *sa);
 extern unsigned int rewrite_out_of_ssa (struct ssaexpand *sa);