From: Andrew Trick <atrick@apple.com>
Date: Tue, 5 Jun 2012 03:44:34 +0000 (+0000)
Subject: sdsched: Use the right heuristics when -mcpu is not provided and we have no itinerary.
X-Git-Url: http://plrg.eecs.uci.edu/git/?a=commitdiff_plain;h=4eb4e5eb224b3d737558bcda8a0a369cc9d800e6;p=oota-llvm.git

sdsched: Use the right heuristics when -mcpu is not provided and we have no itinerary.
Use ILP heuristics for long latency instrs if no scoreboard exists.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@157978 91177308-0d34-0410-b5e6-96231b3b80d8
---

diff --git a/lib/CodeGen/SelectionDAG/ScheduleDAGRRList.cpp b/lib/CodeGen/SelectionDAG/ScheduleDAGRRList.cpp
index e90373c0318..67f42b18ee1 100644
--- a/lib/CodeGen/SelectionDAG/ScheduleDAGRRList.cpp
+++ b/lib/CodeGen/SelectionDAG/ScheduleDAGRRList.cpp
@@ -2331,22 +2331,21 @@ static int BUCompareLatency(SUnit *left, SUnit *right, bool checkPref,
   // and latency.
   if (!checkPref || (left->SchedulingPref == Sched::ILP ||
                      right->SchedulingPref == Sched::ILP)) {
-    if (DisableSchedCycles) {
+    // If neither instruction stalls (!LStall && !RStall) and HazardRecognizer
+    // is enabled, grouping instructions by cycle, then its height is already
+    // covered so only its depth matters. We also reach this point if both stall
+    // but have the same height.
+    if (!SPQ->getHazardRec()->isEnabled()) {
       if (LHeight != RHeight)
         return LHeight > RHeight ? 1 : -1;
     }
-    else {
-      // If neither instruction stalls (!LStall && !RStall) then
-      // its height is already covered so only its depth matters. We also reach
-      // this if both stall but have the same height.
-      int LDepth = left->getDepth() - LPenalty;
-      int RDepth = right->getDepth() - RPenalty;
-      if (LDepth != RDepth) {
-        DEBUG(dbgs() << "  Comparing latency of SU (" << left->NodeNum
-              << ") depth " << LDepth << " vs SU (" << right->NodeNum
-              << ") depth " << RDepth << "\n");
-        return LDepth < RDepth ? 1 : -1;
-      }
+    int LDepth = left->getDepth() - LPenalty;
+    int RDepth = right->getDepth() - RPenalty;
+    if (LDepth != RDepth) {
+      DEBUG(dbgs() << "  Comparing latency of SU (" << left->NodeNum
+            << ") depth " << LDepth << " vs SU (" << right->NodeNum
+            << ") depth " << RDepth << "\n");
+      return LDepth < RDepth ? 1 : -1;
     }
     if (left->Latency != right->Latency)
       return left->Latency > right->Latency ? 1 : -1;