diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index 75333143b52..b0f45f6dffe 100644
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,9 @@
+2003-04-08  Hans-Peter Nilsson  <hp@axis.com>
+
+	* reorg.c (fill_slots_from_thread): When considering changing the
+	insn following a reg-to-reg copy insn to use the source reg of the
+	copy, bail out if there's overlap between the registers.
+
 2003-04-08  Zdenek Dvorak  <rakdver@atrey.karlin.mff.cuni.cz>
 
 	* function.c (postponed_insns): New.
diff --git a/gcc/reorg.c b/gcc/reorg.c
index e3859a6db41..161e7b03ab2 100644
--- a/gcc/reorg.c
+++ b/gcc/reorg.c
@@ -2813,11 +2813,13 @@ fill_slots_from_thread (insn, condition, thread, opposite_thread, likely,
 	 that would make the replacement into the insn invalid.  We also can't
 	 do this if it modifies our source, because it might be an earlyclobber
 	 operand.  This latter test also prevents updating the contents of
-	 a PRE_INC.  */
+	 a PRE_INC.  We also can't do this if there's overlap of source and
+	 destination.  Overlap may happen for larger-than-register-size modes.  */
 
       if (GET_CODE (trial) == INSN && GET_CODE (pat) == SET
 	  && GET_CODE (SET_SRC (pat)) == REG
-	  && GET_CODE (SET_DEST (pat)) == REG)
+	  && GET_CODE (SET_DEST (pat)) == REG
+	  && !reg_overlap_mentioned_p (SET_DEST (pat), SET_SRC (pat)))
 	{
 	  rtx next = next_nonnote_insn (trial);