[llvm] r190177 - mi-sched: Reorder Cyclicpath (latency) and CriticalMax (pressure) heuristics.

[Andrew Trick]

Author: atrick
Date: Fri Sep  6 12:32:36 2013
New Revision: 190177

URL: http://llvm.org/viewvc/llvm-project?rev=190177&view=rev
Log:
mi-sched: Reorder Cyclicpath (latency) and CriticalMax (pressure) heuristics.

The latency based scheduling could induce spills in some cases.

Modified:
    llvm/trunk/lib/CodeGen/MachineScheduler.cpp

Modified: llvm/trunk/lib/CodeGen/MachineScheduler.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/CodeGen/MachineScheduler.cpp?rev=190177&r1=190176&r2=190177&view=diff
==============================================================================
--- llvm/trunk/lib/CodeGen/MachineScheduler.cpp (original)
+++ llvm/trunk/lib/CodeGen/MachineScheduler.cpp Fri Sep  6 12:32:36 2013
@@ -2469,16 +2469,16 @@ void ConvergingScheduler::tryCandidate(S
                                                TryCand, Cand, RegExcess))
     return;
 
-  // For loops that are acyclic path limited, aggressively schedule for latency.
-  if (Rem.IsAcyclicLatencyLimited && tryLatency(TryCand, Cand, Zone))
-    return;
-
   // Avoid increasing the max critical pressure in the scheduled region.
   if (DAG->isTrackingPressure() && tryPressure(TryCand.RPDelta.CriticalMax,
                                                Cand.RPDelta.CriticalMax,
                                                TryCand, Cand, RegCritical))
     return;
 
+  // For loops that are acyclic path limited, aggressively schedule for latency.
+  if (Rem.IsAcyclicLatencyLimited && tryLatency(TryCand, Cand, Zone))
+    return;
+
   // Keep clustered nodes together to encourage downstream peephole
   // optimizations which may reduce resource requirements.
   //