commit 0a7056fe52724d9da0ee691e770e5500ac2bb584
author Bill Wendling <isanbard@gmail.com> Tue Jan 05 23:48:12 2010 +0000
committer Bill Wendling <isanbard@gmail.com> Tue Jan 05 23:48:12 2010 +0000
tree 0de597e9ea58ed9862c0e2b1a2228761fb0382a9
parent 1be1c636341381eb5d919550b54784c5a73f517c

Add a semi-primitive form of scheduling via the "SDNode ordering" to the
bottom-up scheduler. We prefer the lower order number.

llvm-svn: 92806

llvm/lib/CodeGen/SelectionDAG/ScheduleDAGRRList.cpp

diff --git a/llvm/lib/CodeGen/SelectionDAG/ScheduleDAGRRList.cpp b/llvm/lib/CodeGen/SelectionDAG/ScheduleDAGRRList.cpp
index 0727bf9..1ad7919 100644
--- a/llvm/lib/CodeGen/SelectionDAG/ScheduleDAGRRList.cpp
+++ b/llvm/lib/CodeGen/SelectionDAG/ScheduleDAGRRList.cpp
@@ -1038,6 +1038,10 @@
         return 0;
       return SethiUllmanNumbers[SU->NodeNum];
     }
+
+    unsigned getNodeOrdering(const SUnit *SU) const {
+      return scheduleDAG->DAG->GetOrdering(SU->getNode());
+    }
     
     unsigned size() const { return Queue.size(); }
 
@@ -1120,6 +1124,14 @@
 
 // Bottom up
 bool bu_ls_rr_sort::operator()(const SUnit *left, const SUnit *right) const {
+  unsigned LOrder = SPQ->getNodeOrdering(left);
+  unsigned ROrder = SPQ->getNodeOrdering(right);
+
+  // Prefer an ordering where the lower the non-zero order number, the higher
+  // the preference.
+  if ((LOrder || ROrder) && LOrder != ROrder)
+    return LOrder != 0 && (LOrder < ROrder || ROrder == 0);
+
   unsigned LPriority = SPQ->getNodePriority(left);
   unsigned RPriority = SPQ->getNodePriority(right);
   if (LPriority != RPriority)