re PR debug/48866 (gcc hangs when -g is set)

PR debug/48866
* df.h (enum debug_temp_where): New.
(dead_debug_init, dead_debug_finish) Declare.
(dead_debug_add, dead_debug_insert_temp): Declare.
(struct dead_debug_use, struct dead_debug): Moved from...
* df-problems.c: ... here.
(df_set_unused_notes_for_mw): Bind debug uses of unused regno
to a debug temp.
(df_create_unused_note): Likewise.
(df_set_dead_notes_for_mw): Move comment where it belongs.
(dead_debug_init): Export.
(dead_debug_reset_uses): New, factored out of...
(dead_debug_finish): ...this.  Export.
(dead_debug_reset): Remove.
(dead_debug_add): Export.
(dead_debug_insert_before): Rename to...
(dead_debug_insert_temp): ... this.  Add where argument.  Export.
Locate stored value for BEFORE_WITH_VALUE.  Avoid repeat inserts.
Return insertion count.
(df_note_bb_compute): Adjust.
* dce.c (word_dce_process_block): Adjust dead debug uses.
(dce_process_block): Likewise.

From-SVN: r186422

1 files changed, 42 insertions, 0 deletions

diff --git a/gcc/df.h b/gcc/df.h
index aec9788..c0fabb9 100644
--- a/gcc/df.h
+++ b/gcc/df.h
@@ -1101,4 +1101,46 @@ extern void union_defs (df_ref, struct web_entry *,
 			unsigned int *used, struct web_entry *,
 			bool (*fun) (struct web_entry *, struct web_entry *));
 
+/* Debug uses of dead regs.  */
+
+/* Node of a linked list of uses of dead REGs in debug insns.  */
+struct dead_debug_use
+{
+  df_ref use;
+  struct dead_debug_use *next;
+};
+
+/* Linked list of the above, with a bitmap of the REGs in the
+   list.  */
+struct dead_debug
+{
+  struct dead_debug_use *head;
+  bitmap used;
+  bitmap to_rescan;
+};
+
+/* This type controls the behavior of dead_debug_insert_temp WRT
+   UREGNO and INSN.  */
+enum debug_temp_where
+  {
+    /* Bind a newly-created debug temporary to a REG for UREGNO, and
+       insert the debug insn before INSN.  REG is expected to die at
+       INSN.  */
+    DEBUG_TEMP_BEFORE_WITH_REG = -1,
+    /* Bind a newly-created debug temporary to the value INSN stores
+       in REG, and insert the debug insn before INSN.  */
+    DEBUG_TEMP_BEFORE_WITH_VALUE = 0,
+    /* Bind a newly-created debug temporary to a REG for UREGNO, and
+       insert the debug insn after INSN.  REG is expected to be set at
+       INSN.  */
+    DEBUG_TEMP_AFTER_WITH_REG = 1
+  };
+
+extern void dead_debug_init (struct dead_debug *, bitmap);
+extern void dead_debug_finish (struct dead_debug *, bitmap);
+extern void dead_debug_add (struct dead_debug *, df_ref, unsigned int);
+extern int dead_debug_insert_temp (struct dead_debug *,
+				   unsigned int uregno, rtx insn,
+				   enum debug_temp_where);
+
 #endif /* GCC_DF_H */