Turn off pass when using varloc-based LDV

Author: SLTozer

llvm/lib/CodeGen/RemoveLoadsIntoFakeUses.cpp

@@ -32,6 +32,9 @@
 #include "llvm/IR/Function.h"
 #include "llvm/InitializePasses.h"
 #include "llvm/Support/Debug.h"
+#include "llvm/Target/TargetMachine.h"
+
+#include "LiveDebugValues/LiveDebugValues.h"
 
 using namespace llvm;
 
@@ -74,6 +77,10 @@ INITIALIZE_PASS_END(RemoveLoadsIntoFakeUses, DEBUG_TYPE,
                     "Remove Loads Into Fake Uses", false, false)
 
 bool RemoveLoadsIntoFakeUses::runOnMachineFunction(MachineFunction &MF) {
+  // Skip this pass if we would use VarLoc-based LDV, as there may be DBG_VALUE
+  // instructions of the restored values that would become invalid.
+  if (debuginfoShouldUseDebugInstrRef(MF.getTarget().getTargetTriple()))
+    return false;
   // Only run this for functions that have fake uses.
   if (!MF.hasFakeUses() || skipFunction(MF.getFunction()))
     return false;