Add DAG printing for RMW stuff debugging

llvm-svn: 84776

1 files changed, 16 insertions, 0 deletions

diff --git a/llvm/lib/Target/MSP430/MSP430ISelDAGToDAG.cpp b/llvm/lib/Target/MSP430/MSP430ISelDAGToDAG.cpp
index fb841ba006c..550c46897c4 100644
--- a/llvm/lib/Target/MSP430/MSP430ISelDAGToDAG.cpp
+++ b/llvm/lib/Target/MSP430/MSP430ISelDAGToDAG.cpp
@@ -26,6 +26,7 @@
 #include "llvm/CodeGen/SelectionDAG.h"
 #include "llvm/CodeGen/SelectionDAGISel.h"
 #include "llvm/Target/TargetLowering.h"
+#include "llvm/Support/CommandLine.h"
 #include "llvm/Support/Compiler.h"
 #include "llvm/Support/Debug.h"
 #include "llvm/Support/ErrorHandling.h"
@@ -34,6 +35,14 @@
 
 using namespace llvm;
 
+#ifndef NDEBUG
+static cl::opt<bool>
+ViewRMWDAGs("view-msp430-rmw-dags", cl::Hidden,
+          cl::desc("Pop up a window to show isel dags after RMW preprocess"));
+#else
+static const bool ViewRMWDAGs = false;
+#endif
+
 STATISTIC(NumLoadMoved, "Number of loads moved below TokenFactor");
 
 /// MSP430DAGToDAGISel - MSP430 specific code to select MSP430 machine
@@ -288,8 +297,15 @@ void MSP430DAGToDAGISel::PreprocessForRMW() {
 /// InstructionSelect - This callback is invoked by
 /// SelectionDAGISel when it has created a SelectionDAG for us to codegen.
 void MSP430DAGToDAGISel::InstructionSelect() {
+  std::string BlockName;
+  if (ViewRMWDAGs)
+    BlockName = MF->getFunction()->getNameStr() + ":" +
+                BB->getBasicBlock()->getNameStr();
+
   PreprocessForRMW();
 
+  if (ViewRMWDAGs) CurDAG->viewGraph("RMW preprocessed:" + BlockName);
+
   DEBUG(errs() << "Selection DAG after RMW preprocessing:\n");
   DEBUG(CurDAG->dump());