If dbg_declare() or dbg_value() is not lowered by isel then emit DEBUG message instead of creating DBG_VALUE for undefined value in reg0.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@121059 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 2 insertions, 4 deletions

diff --git a/lib/CodeGen/SelectionDAG/FastISel.cpp b/lib/CodeGen/SelectionDAG/FastISel.cpp
index fddd358dcf..490b857b0e 100644
--- a/lib/CodeGen/SelectionDAG/FastISel.cpp
+++ b/lib/CodeGen/SelectionDAG/FastISel.cpp
@@ -55,6 +55,7 @@
 #include "llvm/Target/TargetLowering.h"
 #include "llvm/Target/TargetMachine.h"
 #include "llvm/Support/ErrorHandling.h"
+#include "llvm/Support/Debug.h"
 using namespace llvm;
 
 /// startNewBlock - Set the current block to which generated machine
@@ -517,10 +518,7 @@ bool FastISel::SelectCall(const User *I) {
     } else {
       // We can't yet handle anything else here because it would require
       // generating code, thus altering codegen because of debug info.
-      // Insert an undef so we can see what we dropped.
-      BuildMI(*FuncInfo.MBB, FuncInfo.InsertPt, DL, II)
-        .addReg(0U).addImm(DI->getOffset())
-        .addMetadata(DI->getVariable());
+      DEBUG(dbgs() << "Dropping debug info for " << DI);
     }
     return true;
   }