Index: llvm/trunk/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp
===================================================================
--- llvm/trunk/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp
+++ llvm/trunk/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp
@@ -4854,6 +4854,13 @@
     }
   }
 
+  if (!Op && N.getNode())
+    // Check if frame index is available.
+    if (LoadSDNode *LNode = dyn_cast<LoadSDNode>(N.getNode()))
+      if (FrameIndexSDNode *FINode =
+          dyn_cast<FrameIndexSDNode>(LNode->getBasePtr().getNode()))
+        Op = MachineOperand::CreateFI(FINode->getIndex());
+
   if (!Op) {
     // Check if ValueMap has reg number.
     DenseMap<const Value *, unsigned>::iterator VMI = FuncInfo.ValueMap.find(V);
@@ -4889,13 +4896,6 @@
     }
   }
 
-  if (!Op && N.getNode())
-    // Check if frame index is available.
-    if (LoadSDNode *LNode = dyn_cast<LoadSDNode>(N.getNode()))
-      if (FrameIndexSDNode *FINode =
-          dyn_cast<FrameIndexSDNode>(LNode->getBasePtr().getNode()))
-        Op = MachineOperand::CreateFI(FINode->getIndex());
-
   if (!Op)
     return false;
 
Index: llvm/trunk/test/DebugInfo/X86/stack-args.ll
===================================================================
--- llvm/trunk/test/DebugInfo/X86/stack-args.ll
+++ llvm/trunk/test/DebugInfo/X86/stack-args.ll
@@ -0,0 +1,76 @@
+; RUN: llc -filetype=obj -o - %s | llvm-dwarfdump - | FileCheck %s
+; Generated from:
+; void * __attribute__ (( regparm(2) )) f(void *, void *);
+; void * __attribute__ (( regparm(0) )) g(void *, void *);
+;  
+; void *g(void *t, void *k) {
+;   if (k == (void *)0)
+;     return (void *)0;
+;   return f(t, k);
+; }
+
+; CHECK: DW_TAG_formal_parameter
+; CHECK-NEXT: DW_AT_location	(DW_OP_fbreg +4)
+; CHECK-NEXT: DW_AT_name	("t")
+; CHECK: DW_TAG_formal_parameter
+; CHECK-NEXT: DW_AT_location	(DW_OP_fbreg +8)
+; CHECK-NEXT: DW_AT_name	("k")
+
+source_filename = "t.c"
+target datalayout = "e-m:e-p:32:32-f64:32:64-f80:32-n8:16:32-S128"
+target triple = "i386--linux-gnu"
+
+; Function Attrs: nounwind
+define i8* @g(i8* %t, i8* %k) local_unnamed_addr #0 !dbg !10 {
+entry:
+  call void @llvm.dbg.value(metadata i8* %t, metadata !14, metadata !DIExpression()), !dbg !16
+  call void @llvm.dbg.value(metadata i8* %k, metadata !15, metadata !DIExpression()), !dbg !17
+  %cmp = icmp eq i8* %k, null, !dbg !18
+  br i1 %cmp, label %return, label %if.end, !dbg !20
+
+if.end:                                           ; preds = %entry
+  %call = tail call i8* @f(i8* inreg %t, i8* inreg nonnull %k) #3, !dbg !21
+  br label %return, !dbg !22
+
+return:                                           ; preds = %entry, %if.end
+  %retval.0 = phi i8* [ %call, %if.end ], [ null, %entry ]
+  ret i8* %retval.0, !dbg !23
+}
+
+declare i8* @f(i8* inreg, i8* inreg) local_unnamed_addr
+
+; Function Attrs: nounwind readnone speculatable
+declare void @llvm.dbg.value(metadata, metadata, metadata) #2
+
+attributes #0 = { nounwind  }
+attributes #2 = { nounwind readnone speculatable }
+attributes #3 = { nounwind }
+
+!llvm.dbg.cu = !{!0}
+!llvm.module.flags = !{!5, !6, !7, !8}
+!llvm.ident = !{!9}
+
+!0 = distinct !DICompileUnit(language: DW_LANG_C99, file: !1, producer: "clang version 6.0.0  (llvm/trunk 319230)", isOptimized: true, runtimeVersion: 0, emissionKind: FullDebug, enums: !2, retainedTypes: !3)
+!1 = !DIFile(filename: "t.c", directory: "/")
+!2 = !{}
+!3 = !{!4}
+!4 = !DIDerivedType(tag: DW_TAG_pointer_type, baseType: null, size: 32)
+!5 = !{i32 1, !"NumRegisterParameters", i32 0}
+!6 = !{i32 2, !"Dwarf Version", i32 4}
+!7 = !{i32 2, !"Debug Info Version", i32 3}
+!8 = !{i32 1, !"wchar_size", i32 4}
+!9 = !{!"clang version 6.0.0  (llvm/trunk 319230)"}
+!10 = distinct !DISubprogram(name: "g", scope: !1, file: !1, line: 4, type: !11, isLocal: false, isDefinition: true, scopeLine: 4, flags: DIFlagPrototyped, isOptimized: true, unit: !0, variables: !13)
+!11 = !DISubroutineType(types: !12)
+!12 = !{!4, !4, !4}
+!13 = !{!14, !15}
+!14 = !DILocalVariable(name: "t", arg: 1, scope: !10, file: !1, line: 4, type: !4)
+!15 = !DILocalVariable(name: "k", arg: 2, scope: !10, file: !1, line: 4, type: !4)
+!16 = !DILocation(line: 4, column: 15, scope: !10)
+!17 = !DILocation(line: 4, column: 24, scope: !10)
+!18 = !DILocation(line: 5, column: 9, scope: !19)
+!19 = distinct !DILexicalBlock(scope: !10, file: !1, line: 5, column: 7)
+!20 = !DILocation(line: 5, column: 7, scope: !10)
+!21 = !DILocation(line: 7, column: 10, scope: !10)
+!22 = !DILocation(line: 7, column: 3, scope: !10)
+!23 = !DILocation(line: 8, column: 1, scope: !10)