lower-subreg.c (resolve_simple_move): If called self-recursive...

* lower-subreg.c (resolve_simple_move): If called self-recursive,
	do not delete_insn insns that have not yet been emitted, only
	unlink them with remove_insn.
	* df-scan.c (df_insn_delete): Revert r197492.

From-SVN: r198042

gcc/ChangeLog

@@ -1,3 +1,10 @@
+2013-04-18  Steven Bosscher  <steven@gcc.gnu.org>
+
+	* lower-subreg.c (resolve_simple_move): If called self-recursive,
+	do not delete_insn insns that have not yet been emitted, only
+	unlink them with remove_insn.
+	* df-scan.c (df_insn_delete): Revert r197492.
+
 2013-04-17  Steven Bosscher  <steven@gcc.gnu.org>
 
 	* emit-rtl.c (link_insn_into_chain): Handle chaining of SEQUENCEs.

gcc/df-scan.c

@@ -1158,17 +1158,7 @@ df_insn_delete (rtx insn)
      In any case, we expect BB to be non-NULL at least up to register
      allocation, so disallow a non-NULL BB up to there.  Not perfect
      but better than nothing...  */
-  /* ??? bb can also be NULL if lower-subreg.c:resolve_simple_mov emits
-     an insn into a sequence and then does delete_insn on it.  Not sure
-     if that makes sense, but for now it means this assert cannot work.
-     See PR56738.
-     Disable for now but revisit before the end of GCC 4.9 stage1.  */
-#if 0
   gcc_checking_assert (bb != NULL || reload_completed);
-#else
-  if (bb == NULL)
-    return;
-#endif
 
   df_grow_bb_info (df_scan);
   df_grow_reg_info ();

gcc/lower-subreg.c

@@ -1069,7 +1069,13 @@ resolve_simple_move (rtx set, rtx insn)
 
   emit_insn_before (insns, insn);
 
-  delete_insn (insn);
+  /* If we get here via self-recutsion, then INSN is not yet in the insns
+     chain and delete_insn will fail.  We only want to remove INSN from the
+     current sequence.  See PR56738.  */
+  if (in_sequence_p ())
+    remove_insn (insn);
+  else
+    delete_insn (insn);
 
   return insns;
 }