diff --git a/llvm/lib/Transforms/IPO/WholeProgramDevirt.cpp b/llvm/lib/Transforms/IPO/WholeProgramDevirt.cpp
--- a/llvm/lib/Transforms/IPO/WholeProgramDevirt.cpp
+++ b/llvm/lib/Transforms/IPO/WholeProgramDevirt.cpp
@@ -389,6 +389,19 @@
   return true;
 }
 
+// Returns true if the function definition must be unreachable.
+//
+// Note if this helper function returns true, `F` is guaranteed
+// to be unreachable; if it returns false, `F` might still
+// be unreachable but not covered by this helper function.
+bool mustBeUnreachableFunction(Function *const F) {
+  // A function must be unreachable if its entry block ends with an
+  // 'unreachable'.
+  if (F->isDeclaration())
+    return false;
+  return isa<UnreachableInst>(F->getEntryBlock().getTerminator());
+}
+
 // A virtual call site. VTable is the loaded virtual table pointer, and CS is
 // the indirect virtual call.
 struct VirtualCallSite {
@@ -1038,6 +1051,9 @@
 
     // We can disregard unreachable functions as possible call targets, as
     // unreachable functions shouldn't be called.
+    if (mustBeUnreachableFunction(Fn))
+      continue;
+
     if (ExportSummary && (mustBeUnreachableFunction(
                              lookUpFunctionValueInfo(Fn, ExportSummary)))) {
       continue;
diff --git a/llvm/test/Transforms/WholeProgramDevirt/devirt_single_after_filtering_unreachable_function.ll b/llvm/test/Transforms/WholeProgramDevirt/devirt_single_after_filtering_unreachable_function.ll
new file mode 100644
--- /dev/null
+++ b/llvm/test/Transforms/WholeProgramDevirt/devirt_single_after_filtering_unreachable_function.ll
@@ -0,0 +1,87 @@
+; Test that regular LTO will analyze IR, detect unreachable functions and discard unreachable functions
+; when finding virtual call targets.
+; In this test case, the unreachable function is the virtual deleting destructor of an abstract class.
+
+; RUN: opt -S -passes=wholeprogramdevirt -whole-program-visibility -pass-remarks=wholeprogramdevirt %s 2>&1 | FileCheck %s
+
+; CHECK: remark: tmp.cc:21:3: single-impl: devirtualized a call to _ZN7DerivedD0Ev
+; CHECK: remark: <unknown>:0:0: devirtualized _ZN7DerivedD0Ev
+
+source_filename = "tmp.cc"
+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"
+
+%class.Derived = type { %class.Base }
+%class.Base = type { i32 (...)** }
+
+@_ZTV7Derived = constant { [4 x i8*] } { [4 x i8*] [ i8* bitcast ({ i8*, i8*, i8* }* @_ZTI7Derived to i8*), i8* bitcast (void (%class.Derived*)* @_ZN7DerivedD2Ev to i8*), i8* bitcast (void (%class.Derived*)* @_ZN7DerivedD0Ev to i8*), i8* bitcast (void (%class.Derived*)* @_ZN7Derived1xEv to i8*)] }, !type !0, !type !1, !type !2, !type !3, !vcall_visibility !4
+@_ZTVN10__cxxabiv120__si_class_type_infoE = external global i8*
+@_ZTS7Derived = constant [9 x i8] c"7Derived\00"
+@_ZTVN10__cxxabiv117__class_type_infoE = external global i8*
+@_ZTS4Base = constant [6 x i8] c"4Base\00"
+@_ZTI4Base = constant { i8*, i8* } { i8* bitcast (i8** getelementptr inbounds (i8*, i8** @_ZTVN10__cxxabiv117__class_type_infoE, i64 2) to i8*), i8* getelementptr inbounds ([6 x i8], [6 x i8]* @_ZTS4Base, i32 0, i32 0) }
+@_ZTI7Derived = constant { i8*, i8*, i8* } { i8* bitcast (i8** getelementptr inbounds (i8*, i8** @_ZTVN10__cxxabiv120__si_class_type_infoE, i64 2) to i8*), i8* getelementptr inbounds ([9 x i8], [9 x i8]* @_ZTS7Derived, i32 0, i32 0), i8* bitcast ({ i8*, i8* }* @_ZTI4Base to i8*) }
+@_ZTV4Base = constant { [4 x i8*] } { [4 x i8*] [ i8* bitcast ({ i8*, i8* }* @_ZTI4Base to i8*), i8* bitcast (void (%class.Base*)* @_ZN4BaseD2Ev to i8*), i8* bitcast (void (%class.Base*)* @_ZN4BaseD0Ev to i8*), i8* bitcast (void ()* @__cxa_pure_virtual to i8*)] }, !type !0, !type !1, !vcall_visibility !4
+
+define void @_ZN7Derived1xEv(%class.Derived* %this) {
+entry:
+  ret void
+}
+
+declare i1 @llvm.type.test(i8*, metadata)
+
+declare void @llvm.assume(i1)
+
+define i32 @func(%class.Base* %b) {
+entry:
+  %0 = bitcast %class.Base* %b to void (%class.Base*)***, !dbg !11
+  %vtable = load void (%class.Base*)**, void (%class.Base*)*** %0, !dbg !11
+  %1 = bitcast void (%class.Base*)** %vtable to i8*, !dbg !11
+  %2 = tail call i1 @llvm.type.test(i8* %1, metadata !"_ZTS4Base"), !dbg !11
+  tail call void @llvm.assume(i1 %2), !dbg !11
+  %vfn = getelementptr inbounds void (%class.Base*)*, void (%class.Base*)** %vtable, i64 0, !dbg !11
+  %3 = load void (%class.Base*)*, void (%class.Base*)** %vfn, !dbg !11
+  tail call void %3(%class.Base* %b), !dbg !11
+  ret i32 0
+}
+
+define void @_ZN7DerivedD2Ev(%class.Derived* %this) {
+entry:
+  ret void
+}
+
+define void @_ZN7DerivedD0Ev(%class.Derived* %this) {
+entry:
+  ret void
+}
+
+define void @_ZN4BaseD2Ev(%class.Base* %this) {
+entry:
+  ret void
+}
+
+define void @_ZN4BaseD0Ev(%class.Base* %this) {
+entry:
+  tail call void @llvm.trap()
+  unreachable
+}
+
+declare void @__cxa_pure_virtual() unnamed_addr
+
+declare void @llvm.trap()
+
+!llvm.dbg.cu = !{!5}
+!llvm.module.flags = !{!7}
+
+!0 = !{i64 16, !"_ZTS4Base"}
+!1 = !{i64 32, !"_ZTSM4BaseFvvE.virtual"}
+!2 = !{i64 16, !"_ZTS7Derived"}
+!3 = !{i64 32, !"_ZTSM7DerivedFvvE.virtual"}
+!4 = !{i64 1}
+!5 = distinct !DICompileUnit(language: DW_LANG_C_plus_plus_14, file: !6, isOptimized: true, runtimeVersion: 0, emissionKind: NoDebug, splitDebugInlining: false, nameTableKind: None)
+!6 = !DIFile(filename: "tmp.cc", directory: "")
+!7 = !{i32 2, !"Debug Info Version", i32 3}
+!8 = !DIFile(filename: "tmp.cc", directory: "")
+!9 = !DISubroutineType(types: !{})
+!10= distinct !DISubprogram(name: "func", scope: !8, file: !8, line: 20, type: !9, scopeLine: 20, flags: DIFlagPrototyped, spFlags: DISPFlagDefinition | DISPFlagOptimized, unit: !5, retainedNodes: !{})
+!11 = !DILocation(line: 21, column: 3, scope: !10)
\ No newline at end of file