From: Jeff Law <law@gcc.gnu.org>
Date: Mon, 19 Oct 1998 09:44:34 +0000 (-0600)
Subject: sched.c (update_flow_info): Handle death notes made invalid by instruction splitting.
X-Git-Tag: prereleases/libgcj-0.1~2438
X-Git-Url: http://git.ipfire.org/gitweb.cgi?a=commitdiff_plain;h=5f5702e21c93df1c76780b3ae40f7abe1d3b2a3e;p=thirdparty%2Fgcc.git

sched.c (update_flow_info): Handle death notes made invalid by instruction splitting.

�
        * sched.c (update_flow_info): Handle death notes made invalid by
        instruction splitting.  Partially reverts Oct 15, 1998 patch.
        * haifa-sched.c (update_flow_info): Likewise.

From-SVN: r23170
---

diff --git a/gcc/haifa-sched.c b/gcc/haifa-sched.c
index 806bb396d886..abc45d333842 100644
--- a/gcc/haifa-sched.c
+++ b/gcc/haifa-sched.c
@@ -7987,7 +7987,21 @@ update_flow_info (notes, first, last, orig_insn)
 	         register that was not needed by this instantiation of the
 	         pattern, so we can safely ignore it.  */
 	      if (insn == first)
-		{			
+		{
+		  /* We have accurate death notes after reload now, but this
+		     code is still necessary.  Consider splitting a store into
+		     (subreg:DF (reg:DC) 0).  The death notes will claim the
+		     entire DCmode value is dead.  But after splitting we know
+		     that only part of it is dead.  Ie, the splitting action
+		     actually eliminated the death of one or more hard
+		     registers.  */
+		  if (reload_completed && REG_NOTE_KIND (note) == REG_DEAD)
+		    {
+		      XEXP (note, 1) = REG_NOTES (insn);
+		      REG_NOTES (insn) = note;
+		      break;
+		    }
+			
 		  if (REG_NOTE_KIND (note) != REG_UNUSED)
 		    abort ();