This is the mail archive of the gcc-patches@gcc.gnu.org mailing list for the GCC project.


Index Nav: [Date Index] [Subject Index] [Author Index] [Thread Index]
Message Nav: [Date Prev] [Date Next] [Thread Prev] [Thread Next]

A new patch for delete_trivially_dead_insns


Hi,

Here is a new patch to fix gcc.c-torture/execute/980505-1.c.


-- 
H.J. Lu (hjl@gnu.org)
----
Thu Jun 11 07:21:07 1998  H.J. Lu  (hjl@gnu.org)

	* cse.c (delete_trivially_dead_insns): Update REG_NOTES when
	deleting a insn.

Index: cse.c
===================================================================
RCS file: /home/work/cvs/gnu/egcs/gcc/cse.c,v
retrieving revision 1.1.1.26
diff -u -p -r1.1.1.26 cse.c
--- cse.c	1998/06/09 14:37:37	1.1.1.26
+++ cse.c	1998/06/11 16:46:50
@@ -8893,8 +8894,46 @@ delete_trivially_dead_insns (insns, nreg
 
       if (! live_insn)
 	{
+	  /* We should update REG_NOTES when deleting a insn. */ 
+ 	  rtx set = single_set (insn);
+	  rtx dest;
+	  rtx src = NULL_RTX;
+	  rtx next;
+
+	  if (set)
+	    {
+	      dest = SET_DEST (set);
+	      if (GET_CODE (dest) == REG)
+		{
+		  src = SET_SRC (set);
+		  if (!CONSTANT_P (src)
+		      && GET_CODE (src) != REG
+		      && GET_CODE (src) != SUBREG)
+		    src = NULL_RTX;
+		}
+	    }
+	    
 	  count_reg_usage (insn, counts, NULL_RTX, -1);
-	  delete_insn (insn);
+	  next = delete_insn (insn);
+
+	  if (src)
+	    {
+	      /* We start from here and go forward until DEST is set. */
+	      for (; next; next = NEXT_INSN (next))
+		{
+		  if (REG_NOTES (next)
+		      && (GET_CODE (next) == INSN
+			  || GET_CODE (next) == JUMP_INSN
+			  || GET_CODE (next) == CALL_INSN))
+		    {
+		      set = single_set (next);
+		      if (set && rtx_equal_p (SET_DEST (set), dest))
+			break;
+
+		      replace_rtx (REG_NOTES (next), dest, src);
+		    }
+		}
+	    }
 	}
 
       if (find_reg_note (insn, REG_LIBCALL, NULL_RTX))


Index Nav: [Date Index] [Subject Index] [Author Index] [Thread Index]
Message Nav: [Date Prev] [Date Next] [Thread Prev] [Thread Next]