Index: llvm/trunk/lib/MC/MCObjectFileInfo.cpp
===================================================================
--- llvm/trunk/lib/MC/MCObjectFileInfo.cpp
+++ llvm/trunk/lib/MC/MCObjectFileInfo.cpp
@@ -273,6 +273,17 @@
   case Triple::mips64el:
     FDECFIEncoding = dwarf::DW_EH_PE_sdata8;
     break;
+  case Triple::x86_64:
+    if (RelocM == Reloc::PIC_) {
+      FDECFIEncoding = dwarf::DW_EH_PE_pcrel |
+        ((CMModel == CodeModel::Small || CMModel == CodeModel::Medium)
+         ? dwarf::DW_EH_PE_sdata4 : dwarf::DW_EH_PE_sdata8);
+    } else {
+      FDECFIEncoding =
+        (CMModel == CodeModel::Small || CMModel == CodeModel::Medium)
+        ? dwarf::DW_EH_PE_udata4 : dwarf::DW_EH_PE_absptr;
+    }
+    break;
   default:
     FDECFIEncoding = dwarf::DW_EH_PE_pcrel | dwarf::DW_EH_PE_sdata4;
     break;