diff --git a/llvm/lib/CodeGen/MachineFunction.cpp b/llvm/lib/CodeGen/MachineFunction.cpp
--- a/llvm/lib/CodeGen/MachineFunction.cpp
+++ b/llvm/lib/CodeGen/MachineFunction.cpp
@@ -1148,11 +1148,11 @@
     // locations.
     ;
   } else {
-    // Assert that this is the entry block. If it isn't, then there is some
-    // code construct we don't recognise that deals with physregs across
-    // blocks.
+    // Assert that this is the entry block, or an EH pad. If it isn't, then
+    // there is some code construct we don't recognise that deals with physregs
+    // across blocks.
     assert(!State.first.isVirtual());
-    assert(&*InsertBB.getParent()->begin() == &InsertBB);
+    assert(&*InsertBB.getParent()->begin() == &InsertBB || InsertBB.isEHPad());
   }
 
   // Create DBG_PHI for specified physreg.
diff --git a/llvm/test/DebugInfo/X86/instr-ref-eh-landing-pad.ll b/llvm/test/DebugInfo/X86/instr-ref-eh-landing-pad.ll
new file mode 100644
--- /dev/null
+++ b/llvm/test/DebugInfo/X86/instr-ref-eh-landing-pad.ll
@@ -0,0 +1,92 @@
+; RUN: llc %s -stop-before=finalize-isel -o -\
+; RUN:     -experimental-debug-variable-locations \
+; RUN:   | FileCheck %s
+;
+; Test that instruction referencing variable locations can cope with exception
+; landing pads. Variable locations can be derived from the ABI-defined arguments
+; to landing-pad blocks, which should be treated much like argument locations.
+; This gloriously simple piece of C++:
+;
+;    void a() try { a(); } catch (int *&) { }
+;
+; Produces the code below. A nameless variable is attached to the landing-pad
+; record %0 (via %3), which salvages back to the entry to the landing pad. We
+; should place a DBG_PHI at that point. Instead of crashing.
+;
+; CHECK-LABEL: bb.1.lpad (landing-pad):
+; CHECK:       DBG_PHI $rax, 1
+; CHECK-NEXT:  EH_LABEL
+
+target datalayout = "e-m:e-p270:32:32-p271:32:32-p272:64:64-i64:64-f80:128-n8:16:32:64-S128"
+target triple = "x86_64-unknown-linux-gnu"
+
+@_ZTIPi = external dso_local constant i8*
+
+define dso_local void @_Z1av() local_unnamed_addr #0 personality i8* bitcast (i32 (...)* @__gxx_personality_v0 to i8*) !dbg !8 {
+entry:
+  invoke void @_Z1av()
+          to label %try.cont unwind label %lpad, !dbg !17
+
+lpad:                                             ; preds = %entry
+  %0 = landingpad { i8*, i32 }
+          catch i8* bitcast (i8** @_ZTIPi to i8*), !dbg !19
+  %1 = extractvalue { i8*, i32 } %0, 1, !dbg !19
+  %2 = tail call i32 @llvm.eh.typeid.for(i8* bitcast (i8** @_ZTIPi to i8*)) #3, !dbg !20
+  %matches = icmp eq i32 %1, %2, !dbg !20
+  br i1 %matches, label %catch, label %eh.resume, !dbg !20
+
+catch:                                            ; preds = %lpad
+  %3 = extractvalue { i8*, i32 } %0, 0, !dbg !19
+  %4 = tail call i8* @__cxa_begin_catch(i8* %3) #3, !dbg !20
+  call void @llvm.dbg.value(metadata i8* %3, metadata !13, metadata !DIExpression(DW_OP_plus_uconst, 32, DW_OP_stack_value)), !dbg !21
+  tail call void @__cxa_end_catch() #3, !dbg !22
+  br label %try.cont, !dbg !22
+
+try.cont:                                         ; preds = %entry, %catch
+  ret void, !dbg !24
+
+eh.resume:                                        ; preds = %lpad
+  resume { i8*, i32 } %0, !dbg !20
+}
+
+declare dso_local i32 @__gxx_personality_v0(...)
+
+; Function Attrs: nofree nosync nounwind readnone
+declare i32 @llvm.eh.typeid.for(i8*) #1
+
+declare dso_local i8* @__cxa_begin_catch(i8*) local_unnamed_addr
+
+declare dso_local void @__cxa_end_catch() local_unnamed_addr
+
+; Function Attrs: mustprogress nofree nosync nounwind readnone speculatable willreturn
+declare void @llvm.dbg.value(metadata, metadata, metadata) #2
+
+!llvm.dbg.cu = !{!0}
+!llvm.module.flags = !{!3, !4, !5, !6}
+!llvm.ident = !{!7}
+
+!0 = distinct !DICompileUnit(language: DW_LANG_C_plus_plus_14, file: !1, producer: "clang", isOptimized: true, runtimeVersion: 0, emissionKind: FullDebug, enums: !2, splitDebugInlining: false, nameTableKind: None)
+!1 = !DIFile(filename: "test.cpp", directory: ".")
+!2 = !{}
+!3 = !{i32 7, !"Dwarf Version", i32 4}
+!4 = !{i32 2, !"Debug Info Version", i32 3}
+!5 = !{i32 1, !"wchar_size", i32 4}
+!6 = !{i32 7, !"uwtable", i32 1}
+!7 = !{!"clang"}
+!8 = distinct !DISubprogram(name: "a", linkageName: "_Z1av", scope: !9, file: !9, line: 1, type: !10, scopeLine: 1, flags: DIFlagPrototyped | DIFlagAllCallsDescribed, spFlags: DISPFlagDefinition | DISPFlagOptimized, unit: !0, retainedNodes: !12)
+!9 = !DIFile(filename: "test.cpp", directory: "")
+!10 = !DISubroutineType(types: !11)
+!11 = !{null}
+!12 = !{!13}
+!13 = !DILocalVariable(scope: !8, file: !9, line: 1, type: !14)
+!14 = !DIDerivedType(tag: DW_TAG_reference_type, baseType: !15, size: 64)
+!15 = !DIDerivedType(tag: DW_TAG_pointer_type, baseType: !16, size: 64)
+!16 = !DIBasicType(name: "int", size: 32, encoding: DW_ATE_signed)
+!17 = !DILocation(line: 1, column: 16, scope: !18)
+!18 = distinct !DILexicalBlock(scope: !8, file: !9, line: 1, column: 14)
+!19 = !DILocation(line: 2, column: 1, scope: !18)
+!20 = !DILocation(line: 1, column: 21, scope: !18)
+!21 = !DILocation(line: 0, scope: !8)
+!22 = !DILocation(line: 2, column: 1, scope: !23)
+!23 = distinct !DILexicalBlock(scope: !8, file: !9, line: 1, column: 38)
+!24 = !DILocation(line: 2, column: 1, scope: !8)