(ppc_adjust_cost): New function. Adjust for TYPE_JMPREG.

From-SVN: r6535

gcc/config/rs6000/rs6000.c

@@ -1999,3 +1999,37 @@ output_function_profiler (file, labelno)
   for (i = 3, j = 30; i <= last_parm_reg; i++, j--)
     fprintf (file, "\tai %d,%d,0\n", i, j);
 }
+
+/* Adjust the cost of a scheduling dependency.  Return the new cost of
+   a dependency LINK or INSN on DEP_INSN.  COST is the current cost.  */
+
+int
+ppc_adjust_cost (insn, link, dep_insn, cost)
+     rtx insn;
+     rtx link;
+     rtx dep_insn;
+     int cost;
+{
+  if (! recog_memoized (insn))
+    return 0;
+
+  if (REG_NOTE_KIND (link) != 0)
+    return 0;
+
+  if (REG_NOTE_KIND (link) == 0)
+    {
+      /* Data dependency; DEP_INSN writes a register that INSN reads some
+	 cycles later.  */
+
+      /* Tell the first scheduling pass about the latency between a mtctr
+	 and bctr (and mtlr and br/blr).  The first scheduling pass will not
+	 know about this latency since the mtctr instruction, which has the
+	 latency associated to it, will be generated by reload.  */
+      if (get_attr_type (insn) == TYPE_JMPREG)
+	return TARGET_POWER ? 5 : 4;
+
+      /* Fall out to return default cost.  */
+    }
+
+  return cost;
+}