Patches to reorg.c

[Herman ten Brugge <herman at htbrug dot net dot HCC dot nl>]

Hello Guys,

I found some bugs in reorg.c while helping to port the gcc compiler to
the C30/C40 dsp.
The bugs occur because this dsp has 3 instruction after the delayed branch.
The code in reorg.c is probably mostly used for a single delayed instruction.
Overview of patches:
- I modified the call to fill_slots_from_thread. This routine could be called
  when there was already some code in the delay slot. This can happed at line
  3320.
- Added a call to mark_set_resources at line 3636.
- Checked if the condition codes are modified by instructions in the delayed
  branch slot in routine fill_slots_from_thread at line 3705.
- Marked correct resources in try_merge_delay_insns.

	Herman.

--- reorg.c.org	Sat Oct  4 11:30:32 1997
+++ reorg.c	Thu Oct  2 16:54:41 1997
@@ -266,7 +266,7 @@
 static void mark_target_live_regs PROTO((rtx, struct resources *));
 static void fill_simple_delay_slots PROTO((rtx, int));
 static rtx fill_slots_from_thread PROTO((rtx, rtx, rtx, rtx, int, int,
-					 int, int, int, int *));
+					 int, int, int, int *, rtx));
 static void fill_eager_delay_slots PROTO((rtx));
 static void relax_delay_slots	PROTO((rtx));
 static void make_return_insns	PROTO((rtx));
@@ -1888,9 +1888,13 @@
 	  if (! annul_p)
 	    mark_referenced_resources (next_to_match, &needed, 1);
 	}
-
-      mark_set_resources (trial, &set, 0, 1);
-      mark_referenced_resources (trial, &needed, 1);
+      else
+        {
+          /* We don't mark the resources when we pull them into the delay
+             slot because their results are ready anyway. */
+          mark_set_resources (trial, &set, 0, 1);
+          mark_referenced_resources (trial, &needed, 1);
+        }
     }
 
   /* See if we stopped on a filled insn.  If we did, try to see if its
@@ -1935,6 +1939,12 @@
 
 	      next_to_match = XVECEXP (PATTERN (insn), 0, slot_number);
 	    }
+          else
+            {
+              /* Account for resources set/needed by the last insn.  */
+              mark_set_resources (dtrial, &set, 0, 1);
+              mark_referenced_resources (dtrial, &needed, 1);
+            }
 	}
     }
 
@@ -2159,6 +2169,10 @@
 		   || ! INSN_FROM_TARGET_P (candidate))
 		  && insn_sets_resource_p (candidate, &needed, 1))
 		return 0;
+
+               /* Account for resources set/needed by the last insn.  */
+               mark_set_resources (candidate, &set, 0, 1);
+               mark_referenced_resources (candidate, &needed, 1);
 	    }
 
 
@@ -3322,7 +3336,8 @@
 				    NULL, 1, 1,
 				    own_thread_p (JUMP_LABEL (insn),
 						  JUMP_LABEL (insn), 0),
-				    0, slots_to_fill, &slots_filled);
+				    0, slots_to_fill, &slots_filled,
+				    delay_list);
 
       if (delay_list)
 	unfilled_slots_base[i]
@@ -3452,7 +3467,7 @@
 static rtx
 fill_slots_from_thread (insn, condition, thread, opposite_thread, likely,
 			thread_if_true, own_thread, own_opposite_thread,
-			slots_to_fill, pslots_filled)
+			slots_to_fill, pslots_filled, delay_list)
      rtx insn;
      rtx condition;
      rtx thread, opposite_thread;
@@ -3460,9 +3475,9 @@
      int thread_if_true;
      int own_thread, own_opposite_thread;
      int slots_to_fill, *pslots_filled;
+     rtx delay_list;
 {
   rtx new_thread;
-  rtx delay_list = 0;
   struct resources opposite_needed, set, needed;
   rtx trial;
   int lose = 0;
@@ -3636,6 +3651,8 @@
 
 		  delay_list = add_to_delay_list (temp, delay_list);
 
+		  mark_set_resources (trial, &opposite_needed, 0, 1);
+
 		  if (slots_to_fill == ++(*pslots_filled))
 		    {
 		      /* Even though we have filled all the slots, we
@@ -3705,7 +3722,9 @@
     {
       /* If this is the `true' thread, we will want to follow the jump,
 	 so we can only do this if we have taken everything up to here.  */
-      if (thread_if_true && trial == new_thread)
+      if (thread_if_true && trial == new_thread
+          && !insn_references_resource_p (XVECEXP (PATTERN (trial), 0, 0),
+                                          &opposite_needed, 0))
 	delay_list
 	  = steal_delay_list_from_target (insn, condition, PATTERN (trial),
 					  delay_list, &set, &needed,
@@ -3905,7 +3924,8 @@
 	    = fill_slots_from_thread (insn, condition, insn_at_target,
 				      fallthrough_insn, prediction == 2, 1,
 				      own_target, own_fallthrough,
-				      slots_to_fill, &slots_filled);
+				      slots_to_fill, &slots_filled,
+				      delay_list);
 
 	  if (delay_list == 0 && own_fallthrough)
 	    {
@@ -3920,7 +3940,8 @@
 		= fill_slots_from_thread (insn, condition, fallthrough_insn,
 					  insn_at_target, 0, 0,
 					  own_fallthrough, own_target,
-					  slots_to_fill, &slots_filled);
+					  slots_to_fill, &slots_filled,
+				          delay_list);
 	    }
 	}
       else
@@ -3930,14 +3951,16 @@
 	      = fill_slots_from_thread (insn, condition, fallthrough_insn,
 					insn_at_target, 0, 0,
 					own_fallthrough, own_target,
-					slots_to_fill, &slots_filled);
+					slots_to_fill, &slots_filled,
+					delay_list);
 
 	  if (delay_list == 0)
 	    delay_list
 	      = fill_slots_from_thread (insn, condition, insn_at_target,
 					next_active_insn (insn), 0, 1,
 					own_target, own_fallthrough,
-					slots_to_fill, &slots_filled);
+					slots_to_fill, &slots_filled,
+					delay_list);
 	}
 
       if (delay_list)

-- 
-------------------------------------------------------------------------
Herman ten Brugge			Email:	Haj.Ten.Brugge@net.HCC.nl