Index: lib/Target/NVPTX/NVPTXRegisterInfo.cpp
===================================================================
--- lib/Target/NVPTX/NVPTXRegisterInfo.cpp
+++ lib/Target/NVPTX/NVPTXRegisterInfo.cpp
@@ -119,11 +119,13 @@
   int FrameIndex = MI.getOperand(FIOperandNum).getIndex();
 
   MachineFunction &MF = *MI.getParent()->getParent();
-  int Offset = MF.getFrameInfo().getObjectOffset(FrameIndex) +
-               MI.getOperand(FIOperandNum + 1).getImm();
+  int Offset = MF.getFrameInfo().getObjectOffset(FrameIndex);
 
   // Using I0 as the frame pointer
-  MI.getOperand(FIOperandNum).ChangeToRegister(NVPTX::VRFrame, false);
+  MI.getOperand(FIOperandNum).ChangeToRegister(NVPTX::VRFrame, /*isDef=*/false);
+  // Special processing of dbg_value instructions.
+  if (!MI.isDebugValue())
+    Offset += MI.getOperand(FIOperandNum + 1).getImm();
   MI.getOperand(FIOperandNum + 1).ChangeToImmediate(Offset);
 }
 
Index: test/DebugInfo/NVPTX/dbg-value-const-byref.ll
===================================================================
--- /dev/null
+++ test/DebugInfo/NVPTX/dbg-value-const-byref.ll
@@ -0,0 +1,81 @@
+; RUN: llc -mtriple=nvptx64-nvidia-cuda < %s | FileCheck %s
+; Generated with -O1 from:
+; int f1();
+; void f2(int*);
+; int f3(int);
+;
+; int foo() {
+;   int i = 3;
+;   f3(i);
+;   i = 7;
+;   i = f1();
+;   f2(&i);
+;   return 0;
+; }
+;
+; Test that we generate valid debug info for optimized code,
+; particularly variables that are described as constants and passed
+; by reference.
+;
+; CHECK: DEBUG_VALUE: foo:i <- [DW_OP_deref] [$vrframe+0]
+; CHECK: DEBUG_VALUE: foo:i <- 3
+; CHECK: DEBUG_VALUE: foo:i <- 7
+; CHECK: DEBUG_VALUE: foo:i <- %
+
+; Function Attrs: nounwind ssp uwtable
+define i32 @foo() #0 !dbg !4 {
+entry:
+  %i = alloca i32, align 4
+  call void @llvm.dbg.value(metadata i32 3, metadata !10, metadata !DIExpression()), !dbg !15
+  %call = call i32 @f3(i32 3) #3, !dbg !16
+  call void @llvm.dbg.value(metadata i32 7, metadata !10, metadata !DIExpression()), !dbg !18
+  %call1 = call i32 (...) @f1() #3, !dbg !19
+  call void @llvm.dbg.value(metadata i32 %call1, metadata !10, metadata !DIExpression()), !dbg !19
+  store i32 %call1, i32* %i, align 4, !dbg !19, !tbaa !20
+  call void @llvm.dbg.value(metadata i32* %i, metadata !10, metadata !DIExpression(DW_OP_deref)), !dbg !24
+  call void @f2(i32* %i) #3, !dbg !24
+  ret i32 0, !dbg !25
+}
+
+declare i32 @f3(i32)
+
+declare i32 @f1(...)
+
+declare void @f2(i32*)
+
+; Function Attrs: nounwind readnone
+declare void @llvm.dbg.value(metadata, metadata, metadata) #2
+
+attributes #0 = { nounwind ssp uwtable }
+attributes #2 = { nounwind readnone }
+attributes #3 = { nounwind }
+
+!llvm.dbg.cu = !{!0}
+!llvm.module.flags = !{!11, !12}
+!llvm.ident = !{!13}
+
+!0 = distinct !DICompileUnit(language: DW_LANG_C99, producer: "clang version 3.5.0 ", isOptimized: true, emissionKind: FullDebug, file: !1, enums: !2, retainedTypes: !2, globals: !2, imports: !2)
+!1 = !DIFile(filename: "dbg-value-const-byref.c", directory: "")
+!2 = !{}
+!4 = distinct !DISubprogram(name: "foo", line: 5, isLocal: false, isDefinition: true, virtualIndex: 6, isOptimized: true, unit: !0, scopeLine: 5, file: !1, scope: !5, type: !6, retainedNodes: !9)
+!5 = !DIFile(filename: "dbg-value-const-byref.c", directory: "")
+!6 = !DISubroutineType(types: !7)
+!7 = !{!8}
+!8 = !DIBasicType(tag: DW_TAG_base_type, name: "int", size: 32, align: 32, encoding: DW_ATE_signed)
+!9 = !{!10}
+!10 = !DILocalVariable(name: "i", line: 6, scope: !4, file: !5, type: !8)
+!11 = !{i32 2, !"Dwarf Version", i32 2}
+!12 = !{i32 1, !"Debug Info Version", i32 3}
+!13 = !{!"clang version 3.5.0 "}
+!14 = !{i32 3}
+!15 = !DILocation(line: 6, scope: !4)
+!16 = !DILocation(line: 7, scope: !4)
+!17 = !{i32 7}
+!18 = !DILocation(line: 8, scope: !4)
+!19 = !DILocation(line: 9, scope: !4)
+!20 = !{!21, !21, i64 0}
+!21 = !{!"int", !22, i64 0}
+!22 = !{!"omnipotent char", !23, i64 0}
+!23 = !{!"Simple C/C++ TBAA"}
+!24 = !DILocation(line: 10, scope: !4)
+!25 = !DILocation(line: 11, scope: !4)