Index: llvm/lib/CodeGen/MachineSink.cpp
===================================================================
--- llvm/lib/CodeGen/MachineSink.cpp
+++ llvm/lib/CodeGen/MachineSink.cpp
@@ -268,6 +268,16 @@
 INITIALIZE_PASS_END(MachineSinking, DEBUG_TYPE,
                     "Machine code sinking", false, false)
 
+static unsigned sizeNoDbg(const MachineBasicBlock &MBB) {
+  unsigned Size = 0;
+  for (auto &MI : MBB) {
+    if (MI.isDebugInstr())
+      continue;
+    Size++;
+  }
+  return Size;
+}
+
 bool MachineSinking::PerformTrivialForwardCoalescing(MachineInstr &MI,
                                                      MachineBasicBlock *MBB) {
   if (!MI.isCopy())
@@ -1175,7 +1185,7 @@
 
       // If this BB is too big or the block number in straight line between From
       // and To is too big, stop searching to save compiling time.
-      if (BB->size() > SinkLoadInstsPerBlockThreshold ||
+      if (sizeNoDbg(*BB) > SinkLoadInstsPerBlockThreshold ||
           HandledDomBlocks.size() > SinkLoadBlocksThreshold) {
         for (auto *DomBB : HandledDomBlocks) {
           if (DomBB != BB && DT->dominates(DomBB, BB))
@@ -1277,7 +1287,7 @@
         dbgs() << "CycleSink: Not sinking, sink block is the preheader\n");
     return false;
   }
-  if (SinkBlock->size() > SinkLoadInstsPerBlockThreshold) {
+  if (sizeNoDbg(*SinkBlock) > SinkLoadInstsPerBlockThreshold) {
     LLVM_DEBUG(
         dbgs() << "CycleSink: Not Sinking, block too large to analyse.\n");
     return false;