MachineScheduler: Add -misched-print-dags flag

Add a flag to dump the schedule DAG to the debug stream. This will be
used in upcoming commits to test schedule DAG mutations such as macro
fusion.

llvm-svn: 342589

1 files changed, 6 insertions, 1 deletions

diff --git a/llvm/lib/CodeGen/MachineScheduler.cpp b/llvm/lib/CodeGen/MachineScheduler.cpp
index da01f6f5bbe..d60f17ad07f 100644
--- a/llvm/lib/CodeGen/MachineScheduler.cpp
+++ b/llvm/lib/CodeGen/MachineScheduler.cpp
@@ -100,8 +100,11 @@ static cl::opt<std::string> SchedOnlyFunc("misched-only-func", cl::Hidden,
   cl::desc("Only schedule this function"));
 static cl::opt<unsigned> SchedOnlyBlock("misched-only-block", cl::Hidden,
                                         cl::desc("Only schedule this MBB#"));
+static cl::opt<bool> PrintDAGs("misched-print-dags", cl::Hidden,
+                              cl::desc("Print schedule DAGs"));
 #else
-static bool ViewMISchedDAGs = false;
+static const bool ViewMISchedDAGs = false;
+static const bool PrintDAGs = false;
 #endif // NDEBUG
 
 /// Avoid quadratic complexity in unusually large basic blocks by limiting the
@@ -765,6 +768,7 @@ void ScheduleDAGMI::schedule() {
   findRootsAndBiasEdges(TopRoots, BotRoots);
 
   LLVM_DEBUG(dump());
+  if (PrintDAGs) dump();
   if (ViewMISchedDAGs) viewGraph();
 
   // Initialize the strategy before modifying the DAG.
@@ -1218,6 +1222,7 @@ void ScheduleDAGMILive::schedule() {
   SchedImpl->initialize(this);
 
   LLVM_DEBUG(dump());
+  if (PrintDAGs) dump();
   if (ViewMISchedDAGs) viewGraph();
 
   // Initialize ready queues now that the DAG and priority data are finalized.