Fix irix6 -O3 -funroll-all-loops bootstrap failure reported by Kaveh Ghazi.

	* gcse.c (add_label_notes): New function.
	(pre_insert_insn): Call it.
	* unroll.c (unroll_loop): Look for insns with a REG_LABEL note, and
	pass the label to set_label_in_map.

From-SVN: r20658

gcc/ChangeLog

+Mon Jun 22 12:01:48 1998  Jim Wilson  <wilson@cygnus.com>
+
+	* gcse.c (add_label_notes): New function.
+	(pre_insert_insn): Call it.
+	* unroll.c (unroll_loop): Look for insns with a REG_LABEL note, and
+	pass the label to set_label_in_map.
+
 Mon Jun 22 19:01:14 1998  Dave Love  <d.love@dl.ac.uk>
 
 	* Makefile.in (install-info): Fix typpo in previous change.

gcc/gcse.c

@@ -641,6 +641,8 @@ static void pre_insert_copies         PROTO ((void));
 static int pre_delete                 PROTO ((void));
 static int pre_gcse                   PROTO ((void));
 static int one_pre_gcse_pass          PROTO ((rtx, int));
+
+static void add_label_notes	      PROTO ((rtx, rtx));
 
 /* Entry point for global common subexpression elimination.
    F is the first instruction in the function.  */
@@ -4354,6 +4356,7 @@ pre_insert_insn (expr, bb)
 #endif
       /* FIXME: What if something in cc0/jump uses value set in new insn?  */
       new_insn = emit_insn_before (pat, insn);
+      add_label_notes (SET_SRC (pat), new_insn);
       if (BLOCK_HEAD (bb) == insn)
 	BLOCK_HEAD (bb) = new_insn;
       /* Keep block number table up to date.  */
@@ -4364,6 +4367,7 @@ pre_insert_insn (expr, bb)
   else
     {
       new_insn = emit_insn_after (pat, insn);
+      add_label_notes (SET_SRC (pat), new_insn);
       BLOCK_END (bb) = new_insn;
       /* Keep block number table up to date.  */
       set_block_num (new_insn, bb);
@@ -4695,3 +4699,50 @@ one_pre_gcse_pass (f, pass)
 
   return changed;
 }
+
+/* If X contains any LABEL_REF's, add REG_LABEL notes for them to INSN.
+   We have to add REG_LABEL notes, because the following loop optimization
+   pass requires them.  */
+
+/* ??? This is very similar to the loop.c add_label_notes function.  We
+   could probably share code here.  */
+
+/* ??? If there was a jump optimization pass after gcse and before loop,
+   then we would not need to do this here, because jump would add the
+   necessary REG_LABEL notes.  */
+
+static void
+add_label_notes (x, insn)
+     rtx x;
+     rtx insn;
+{
+  enum rtx_code code = GET_CODE (x);
+  int i, j;
+  char *fmt;
+
+  if (code == LABEL_REF && !LABEL_REF_NONLOCAL_P (x))
+    {
+      rtx next = next_real_insn (XEXP (x, 0));
+
+      /* Don't record labels that refer to dispatch tables.
+	 This is not necessary, since the tablejump references the same label.
+	 And if we did record them, flow.c would make worse code.  */
+      if (next == 0
+	  || ! (GET_CODE (next) == JUMP_INSN
+		&& (GET_CODE (PATTERN (next)) == ADDR_VEC
+		    || GET_CODE (PATTERN (next)) == ADDR_DIFF_VEC)))
+	REG_NOTES (insn) = gen_rtx_EXPR_LIST (REG_LABEL, XEXP (x, 0),
+					      REG_NOTES (insn));
+      return;
+    }
+
+  fmt = GET_RTX_FORMAT (code);
+  for (i = GET_RTX_LENGTH (code) - 1; i >= 0; i--)
+    {
+      if (fmt[i] == 'e')
+	add_label_notes (XEXP (x, i), insn);
+      else if (fmt[i] == 'E')
+	for (j = XVECLEN (x, i) - 1; j >= 0; j--)
+	  add_label_notes (XVECEXP (x, i, j), insn);
+    }
+}

gcc/unroll.c

@@ -691,6 +691,8 @@ unroll_loop (loop_end, insn_count, loop_start, end_insert_before,
 
   for (insn = copy_start; insn != loop_end; insn = NEXT_INSN (insn))
     {
+      rtx note;
+
       if (GET_CODE (insn) == CODE_LABEL)
 	local_label[CODE_LABEL_NUMBER (insn)] = 1;
       else if (GET_CODE (insn) == JUMP_INSN)
@@ -716,6 +718,9 @@ unroll_loop (loop_end, insn_count, loop_start, end_insert_before,
 		}
 	    }
 	}
+      else if (note = find_reg_note (insn, REG_LABEL, NULL_RTX))
+	set_label_in_map (map, CODE_LABEL_NUMBER (XEXP (note, 0)),
+			  XEXP (note, 0));
     }
 
   /* Allocate space for the insn map.  */