flow.c (propagate_one_insn): Revise yesterday's patch.

        * flow.c (propagate_one_insn): Revise yesterday's patch.  Delete
        a dead insn with a REG_RETVAL note when the entire libcall is not
        dead and remove the associated REG_LIBCALL note at the same time.

From-SVN: r54065

gcc/ChangeLog

+2002-05-30  Jeff Law <law@redhat.com>
+
+	* flow.c (propagate_one_insn): Revise yesterday's patch.  Delete
+	a dead insn with a REG_RETVAL note when the entire libcall is not
+	dead and remove the associated REG_LIBCALL note at the same time.
+
 Thu May 30 19:54:30 2002  J"orn Rennecke <joern.rennecke@superh.com>
 
 	* lcm.c (output.h): #include.

gcc/flow.c

@@ -1643,8 +1643,27 @@ propagate_one_insn (pbi, insn)
 
       if (libcall_is_dead)
 	prev = propagate_block_delete_libcall ( insn, note);
-      else if (!note)
-	propagate_block_delete_insn (insn);
+      else
+	{
+
+	  if (note)
+	    {
+	      /* If INSN contains a RETVAL note and is dead, but the libcall
+		 as a whole is not dead, then we want to remove INSN, but
+		 not the whole libcall sequence.
+
+		 However, we need to also remove the dangling REG_LIBCALL	
+		 note so that we do not have mis-matched LIBCALL/RETVAL
+		 notes.  In theory we could find a new location for the
+		 REG_RETVAL note, but it hardly seems worth the effort.  */
+	      rtx libcall_note;
+	 
+	      libcall_note
+		= find_reg_note (XEXP (note, 0), REG_LIBCALL, NULL_RTX);
+	      remove_note (XEXP (note, 0), libcall_note);
+	    }
+	  propagate_block_delete_insn (insn);
+	}
 
       return prev;
     }