[llvm] 328bb44 - Add a policy to enable computing SchedDFSResult.

[Mark Lacey via llvm-commits]

Author: Mark Lacey
Date: 2020-04-22T16:36:11-07:00
New Revision: 328bb446ddd2c03e4da3e9aa0473fa2f1c52d34e

URL: https://github.com/llvm/llvm-project/commit/328bb446ddd2c03e4da3e9aa0473fa2f1c52d34e
DIFF: https://github.com/llvm/llvm-project/commit/328bb446ddd2c03e4da3e9aa0473fa2f1c52d34e.diff

LOG: Add a policy to enable computing SchedDFSResult.

Summary:
Make GenericScheduler compute SchedDFSResult on initialization if
the policy is set. This makes it possible to create classes
that extend GenericScheduler and rely on the results of SchedDFSResult,
e.g. to perform subtree scheduling.

NFC unless the policy is set.

Subscribers: MatzeB, hiraditya, javed.absar, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D78432

Added: 
    

Modified: 
    llvm/include/llvm/CodeGen/MachineScheduler.h
    llvm/lib/CodeGen/MachineScheduler.cpp

Removed: 
    


################################################################################
diff  --git a/llvm/include/llvm/CodeGen/MachineScheduler.h b/llvm/include/llvm/CodeGen/MachineScheduler.h
index 6cebaa47fe6a..f858b6905e8f 100644
--- a/llvm/include/llvm/CodeGen/MachineScheduler.h
+++ b/llvm/include/llvm/CodeGen/MachineScheduler.h
@@ -186,6 +186,9 @@ struct MachineSchedPolicy {
   // first.
   bool DisableLatencyHeuristic = false;
 
+  // Compute DFSResult for use in scheduling heuristics.
+  bool ComputeDFSResult = false;
+
   MachineSchedPolicy() = default;
 };
 

diff  --git a/llvm/lib/CodeGen/MachineScheduler.cpp b/llvm/lib/CodeGen/MachineScheduler.cpp
index 5cfc01952756..55b007533861 100644
--- a/llvm/lib/CodeGen/MachineScheduler.cpp
+++ b/llvm/lib/CodeGen/MachineScheduler.cpp
@@ -2733,6 +2733,9 @@ void GenericScheduler::initialize(ScheduleDAGMI *dag) {
   SchedModel = DAG->getSchedModel();
   TRI = DAG->TRI;
 
+  if (RegionPolicy.ComputeDFSResult)
+    DAG->computeDFSResult();
+
   Rem.init(DAG, SchedModel);
   Top.init(DAG, SchedModel, &Rem);
   Bot.init(DAG, SchedModel, &Rem);