Insert the debugging instructions in one fell-swoop so that it doesn't call the

expensive "getFirstTerminator" call. This reduces the time of compilation in
PR12258 from >10 minutes to < 10 seconds.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@152704 91177308-0d34-0410-b5e6-96231b3b80d8

diff --git a/lib/CodeGen/SelectionDAG/ScheduleDAGSDNodes.cpp b/lib/CodeGen/SelectionDAG/ScheduleDAGSDNodes.cpp
index d2aec08534afdab084524536fef18d1981969c71..69dd813b24e0171b973f805b2de7d795cff154ed 100644 (file)
--- a/lib/CodeGen/SelectionDAG/ScheduleDAGSDNodes.cpp
+++ b/lib/CodeGen/SelectionDAG/ScheduleDAGSDNodes.cpp
@@ -855,16 +855,17 @@ EmitSchedule(MachineBasicBlock::iterator &InsertPos) {
     }
     // Add trailing DbgValue's before the terminator. FIXME: May want to add
     // some of them before one or more conditional branches?
+    SmallVector<MachineInstr*, 8> DbgMIs;
     while (DI != DE) {
-      MachineBasicBlock *InsertBB = Emitter.getBlock();
-      MachineBasicBlock::iterator Pos= Emitter.getBlock()->getFirstTerminator();
-      if (!(*DI)->isInvalidated()) {
-        MachineInstr *DbgMI= Emitter.EmitDbgValue(*DI, VRBaseMap);
-        if (DbgMI)
-          InsertBB->insert(Pos, DbgMI);
-      }
+      if (!(*DI)->isInvalidated())
+        if (MachineInstr *DbgMI = Emitter.EmitDbgValue(*DI, VRBaseMap))
+          DbgMIs.push_back(DbgMI);
       ++DI;
     }
+
+    MachineBasicBlock *InsertBB = Emitter.getBlock();
+    MachineBasicBlock::iterator Pos = InsertBB->getFirstTerminator();
+    InsertBB->insert(Pos, DbgMIs.begin(), DbgMIs.end());
   }
 
   InsertPos = Emitter.getInsertPos();