Add DBG_VALUE support to the linear DAG scheduler

The fast/linear DAG scheduler doesn't lower DBG_VALUEs except for
function entry nodes.

Patch by Joshua Cranmer!

Differential Revision: https://reviews.llvm.org/D43028

llvm-svn: 326631

1 files changed, 14 insertions, 1 deletions

diff --git a/llvm/lib/CodeGen/SelectionDAG/ScheduleDAGFast.cpp b/llvm/lib/CodeGen/SelectionDAG/ScheduleDAGFast.cpp
index 698e14453d1..f55d85f01e7 100644
--- a/llvm/lib/CodeGen/SelectionDAG/ScheduleDAGFast.cpp
+++ b/llvm/lib/CodeGen/SelectionDAG/ScheduleDAGFast.cpp
@@ -13,6 +13,7 @@
 
 #include "InstrEmitter.h"
 #include "ScheduleDAGSDNodes.h"
+#include "SDNodeDbgValue.h"
 #include "llvm/ADT/STLExtras.h"
 #include "llvm/ADT/SmallSet.h"
 #include "llvm/ADT/Statistic.h"
@@ -767,12 +768,24 @@ ScheduleDAGLinearize::EmitSchedule(MachineBasicBlock::iterator &InsertPos) {
       dbgs() << "\n*** Final schedule ***\n";
     });
 
-  // FIXME: Handle dbg_values.
   unsigned NumNodes = Sequence.size();
+  MachineBasicBlock *BB = Emitter.getBlock();
   for (unsigned i = 0; i != NumNodes; ++i) {
     SDNode *N = Sequence[NumNodes-i-1];
     DEBUG(N->dump(DAG));
     Emitter.EmitNode(N, false, false, VRBaseMap);
+
+    // Emit any debug values associated with the node.
+    if (N->getHasDebugValue()) {
+      MachineBasicBlock::iterator InsertPos = Emitter.getInsertPos();
+      for (auto DV : DAG->GetDbgValues(N)) {
+        if (DV->isInvalidated())
+          continue;
+        if (auto *DbgMI = Emitter.EmitDbgValue(DV, VRBaseMap))
+          BB->insert(InsertPos, DbgMI);
+        DV->setIsInvalidated();
+      }
+    }
   }
 
   DEBUG(dbgs() << '\n');